Report to the U.S. Congress
Under Public Law 109-58, The Energy Policy Act of 2005
Report on
Alternatives to Industrial Radioactive Sources
DRAFT May 30, 2006
U.S. Department of Energy
Alternatives to Industrial Radioactive Sources
Table of Contents
Page
Executive Summary .................................................................................................... i
Part 1: Survey of Industrial Applications of Large Radioactive Sources
1.
2.
3.
4.
5.
6.
7.
8.
9.
Background........................................................................................................................ 1
Industrial Applications of Category 1 Radioactive Sealed Sources................................... 3
Industrial Applications of Category 2 Radioactive Sealed Sources ................................ 4
Well Logging Sources........................................................................................................ 4
Current Domestic and International Programs to Manage and Dispose of
Radioactive Sources .......................................................................................................... 5
5.1 Domestic Efforts to Establish and Manage Radioactive
Sealed Source Inventories........................................................................................... 5
5.1.1 Regulations Governing Sealed Sources ........................................................ 5
5.1.2 Development of a National Source Tracking System (NSTS) ...................... 7
5.1.3 DOE and NRC Data Calls for Interim Inventories .......................................... 8
5.1.4 Radioactive Sources and the Department of Defense................................... 8
5.1.5 U.S. Department of State .............................................................................. 8
5.2 International Efforts to Establish and Manage Radioactive Sealed
Source Inventories....................................................................................................... .9
5.2.1 Export/Import Controls .................................................................................. 10
Domestic Disposal Options for Radioactive Sources ........................................................ 10
6.1 Disposal of Commercial Radioactive Sources........................................................... 12
6.2 Excess, Unwanted, and Orphan Sources.................................................................. 12
Transportation of Sources ................................................................................................ 13
Research and Development Program Plan ....................................................................... 14
Legislative Recommendations for Alternative Technologies............................................. 16
Part 2: Research and Development Plan for Alternative Technologies
1.
Background........................................................................................................................ 19
2.
3.
4.
5.
6.
Current Status.................................................................................................................... 20
Proposed Research and Development Plan ..................................................................... 20
3.1 Objectives .................................................................................................................... 20
3.2 Challenges ................................................................................................................... 21
3.3 Anticipated Outcomes.................................................................................................. 21
Details of Research and Development Plan...................................................................... 21
4.1 Replace with Nonradioactive Materials ....................................................................... 21
4.2 Replace with Less Hazardous and Less Dispersible Material..................................... 22
4.3 Utilize Integrated Security Features if Alternative is Not Available.............................. 24
Need for Incentives............................................................................................................ 25
Recommendations ............................................................................................................. 26
6.1 Research and Development Options.......................................................................... 26
6.2 Collaborative Efforts ................................................................................................... 26
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Alternatives to Industrial Radioactive Sources
Appendices
A.
B.
C.
D.
E.
F.
G.
Acronyms and Abbreviations.............................................................................................
IAEA Code of Conduct List of Categorization of Sources ................................................
Applications for Medical Radioisotopes.............................................................................
Class C Radioisotope Production Methods .......................................................................
United States Regulatory Guidance for Sealed Source Management ..............................
Glossary.............................................................................................................................
References ............................................................................................................
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U.S. Department of Energy
Alternatives to Industrial Radioactive Sources
Executive Summary
The control and management of radioactive sealed sources has become of increased importance
due to the potential for the sources to be used in a malicious act. As part of the response to this
threat, The Energy Policy Act of 2005 (Public Law 109-58), section 957 requires the Secretary of
Energy to furnish a report to Congress by August 1, 2006, on Alternatives to Industrial
Radioactive Sources. Under Subpart E, this task was assigned to the Department of Energy
(DOE) Office of Nuclear Energy (NE). Per Section 957 NE was tasked to perform a survey of
industrial applications of large industrial sources that 1) included well logging sources;
2) considered information on current domestic, international, Department of Defense (DoD),
State Department, and commercial programs to manage and dispose of radioactive sources; and
3) analyzed available disposal options for currently deployed or future sources, and recommended
legislative options for Congress to consider to remedy identified deficiencies.
In addition, NE was tasked to propose a research and development program to develop alternative
technologies that would replace the use of radioactive sealed sources. The goal of this program is
to reduce the availability of radioactive sealed sources that pose health and safety concerns and/or
could be a proliferation risk. Section 957 requests that particle accelerators for well logging and
other industrial applications be addressed in the program plan.
In this report, radioactive sources are considered radioactive sealed sources, i.e., radioactive
material sealed in a capsule or between layers of non-radioactive material (usually metal that is
welded shut) to prevent leakage or escape of the radioactive material. Sealed sources are
physically small in size and range in activity levels from micro Curies to thousands of Curies.
They provide critical capabilities in the oil and gas, electrical power, medical, construction, and
food industries. The primary concern with radioactive sealed sources is the number in use,
combined with their portability and size, making control and management challenging.
A “large industrial source” is considered a Category 1 or 2 sealed source as defined by the
International Atomic Energy Agency in its Code of Conduct on the Safety and Security of
Radioactive Sources (see appendix B). Category 1 sources are the most dangerous and could
cause the death or permanently injure anyone who remains nearby the unshielded material for
minutes to an hour. Typical sources include radioisotope thermoelectric generators, irradiators,
and radiation teletherapy devices. Category 2 sources could be fatal if a person were exposed to
unshielded material for a period of hours to days. These sources are typically used in industrial
gamma radiography and medical brachytherapy devices.
Well logging gauges and other industrial gauges contain sealed sources that are typically
Category 3, and could inflict injury to persons in close proximity for longer periods but are
unlikely to cause fatalities.
Although not specifically mandated under this task, a discussion of medical applications is
addressed in Appendix C. Approximately100 radioisotopes are used in medical diagnosis,
sterilization of medical products, radiotherapy, and research in nuclear medicine. Some medical
devices that utilize radioactive sealed sources also are Category 1 or 2 and should be considered
for further study for alternative technology development.
Although improvements in physical security and regulatory controls can reduce the risks that
radioactive sealed sources would be used in a malicious act, such as a radiological dispersal
device (RDD), the widespread use of radiological source materials also needs to be addressed.
The development of alternatives that do not use radioactive materials is an important strategy to
adopt for both for increased safety and security.
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U.S. Department of Energy
Alternatives to Industrial Radioactive Sources
The proposed research and development program for alternatives will focus on three objectives:
•
Replace radioactive source isotopes with technologies that do not use radioactive materials:
This is the primary objective of the research and development plan. Reducing the number of
sealed sources is the most effective way to reduce all risks associated with sealed sources.
The use of non-radioactive applications would significantly increase worker safety by
completely removing a source of ionizing radiation from the work place as well as greatly
limiting the availability of radioactive sources that might be used for criminal or terrorist
activity.
•
Reduce the effectiveness of sealed sources in harming populations and disrupting
infrastructure: This objective is intended to address situations in which the number of
radioactive sources or the industrial use of these radioactive sources does not have a
technically or economically feasible non- radioactive alternative. This approach would reduce
(1) the ease with which a source can be dispersed, (2) the hazard to humans, or (3) the
difficulty of clean up should the sealed source be used in an RDD event. These sealed
sources would be considered RDD-resistant.
•
Prevent the theft or decrease the recovery time of sealed sources: This object is intended to
address situations for which either non-radioactive or RDD resistant alternatives to existing
sealed sources are not feasible. Reducing the likelihood of the theft or the recovery time may
not mitigate all vulnerabilities.
Developing and deploying alternative technologies may not mitigate all vulnerabilities. That
disused sources could be donated or sold to a foreign country with less controls remains a
potential area of concern. Also, the cost/benefit of the alternative sources may not be attractive to
the end-user. The Federal government may, therefore, need to establish incentives for both
manufacturers and users, including bearing the cost of disposal of existing sources, to reduce
vulnerabilities and address the RDD risk.
Finally, much of the information in this report is based on information contained in the NRC
Draft Report, “Radiation Protection and Security Task Force Report to the President and
Congress,” which is expected to be finalized in August 2006. That draft report is being prepared
in response to Section 651[d] of the Energy Policy Act of 2005 (Public Law 109-58), which tasks
the NRC to report to the President and Congress with recommendations to address the security of
radiation sources in the United States. The Task Force is comprised of multiple Federal agencies
that are addressing 11 topical areas related to the life-cycle of radiation sources. This draft report
gives the most current and detailed information on the management, control, and disposal of
sealed sources. The NRC task force is also addressing whether additional legislative and/or
regulatory changes need to be made for radioactive sealed source security. Other references have
been utilized in addressing this tasking; a list is provided in Appendix G.
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U.S. Department of Energy
Alternatives to Industrial Radioactive Sources
Part 1 Survey of Industrial Applications of Large Radioactive Sources
1. Background
In the Department of Energy (DOE), the Office of Nuclear Energy (NE) has the lead for
responding to Section 957 of the Energy Policy Act of 2005, which requires that the DOE
conduct a survey of industrial applications of large industrial sources, with well logging sources
considered as one class of large industrial sources; supply information on current domestic,
international, Department of Defense (DoD), State Department, and commercial programs to
manage and dispose of radioactive sources; analyze available disposal options for currently
deployed or future sources; and recommend legislative options that Congress may consider to
remedy identified deficiencies.
Because of the concern that nuclear materials could be used by terrorists in a radiological event,
the Federal government is taking action to better secure and account for its nuclear materials. Of
special concern are radioactive sealed sources, which are relatively small in size, easily
transportable, and used widely in medical, academic, industrial, and military applications.
Radioactive materials contained in sealed sources have the potential to be used in radiological
dispersal devices (RDDs). The intent of the RDD is to disperse particles of radioactive materials
into the environment through detonation of a conventional explosive. The use of radioactive
materials in an RDD is widely recognized to have a greater likelihood of physically disruptive
consequences than of lethal radioactive consequences. However, the psychological and economic
consequences of dispersal could be quite severe and carry varying levels of risk to public health.
For example, in addition to creating mass panic, the evacuation and cleanup of contaminated
areas could have serious economic impact.
In the late 1980’s, several Federal agencies identified the need to implement enhanced strategies
to control, manage, and protect radioactive sealed sources that could be used as RDDs. This need
was reinforced and strategies were accelerated after the events of September 11, 2001. Figure 1-1
provides a timeline of actions taken to strengthen the security of sealed source materials.
In conducting its survey, the DOE has adopted international guidance1 to define “large” as a
Category 1 or 2 radioactive sealed source based on activity levels in Curies. Appendix B defines
the IAEA categories and lists the IAEA Code of Conduct radionuclides considered of greatest
risk to public health, safety, and security. The IAEA-defined Category 1 and 2 sealed sources
perform a wide variety of applications in the industrial, medical, and academic communities.
Radioactive sealed sources detect oil and gas deposits in the petroleum industry, measure
thicknesses in the manufacturing sector, and examine welds in the construction industry. The
food industry uses sealed sources to irradiate food to improve its shelf life. In the medical
industry, sealed sources help diagnose and treat cancer. The academic community uses them for
both instruction and research.
1 International Atomic Energy Agency Code of Conduct on the Safety and Security of Radioactive
Sources.
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U.S. Department of Energy
Alternatives to Industrial Radioactive Sources
Figure 1-1: Timeline of Events for Management and Control of Radioactive Sealed Sources*
Pre-9/11/01
A pr 8 7
Licen se Tracking
S yste m
19 9 1
Fina l Ru le :
S ecu rity of
S tore d Ma teria l
1 99 0
DO E’s O ffsite S o u rce
Re cove ry P rog ra m
19 9 1
Rep o rts o f
L o ss o r Th e ft
1 99 7
Fin al Rule :
Ra d io gra ph y Un its
S e cure d to P re ve nt
Tamp e ring
Jun 99
MO U with DO E
o n Ma n ag eme n t
o f S ou rce s
De c 0 0
Fin a l Rule:
G en e ra lly L ice nsed
Device Re gistra tio n
Fe b 0 1
NRC’s L o st S ou rce
E n fo rce me nt Po licy
Ma r 01
G en e ra l L ice nse
Tracking S ystem
/////
/////
1987
19 9 9
20 0 0
2 0 01
1 99 8
20 01
1998 - 2003
D ev elopm ent of IAEA C ode of C onduc1 t
Post-9/11/01
Jun 03
NRC Ord e rs:
P a no ramic Irrad ia tor
Licen see s
Oct 0 1
2 0 02
CRCP D Na tio na l O rph a n
Trila tera l In itia tive :
Ra dioa ctive Ma teria l
US , Mexico , Ca na da
Ma y 03
Disp o sition Pro gra m
NRC/DO E
2 0 01
RDD Rep o rt
S afe gu ard s
A d viso rie s
2002
2001
O ct 0 3
US Co mmitme nt to
Cod e o f Con d uct1
S ep 03
IA EA Bo ard of
G overn ors A d op t
Co de of Co n du ct1
2003
O ct 0 3
Inte rim
Data ba se
Ja n 0 4
NRC O rd ers:
Man u fa ctu re rs &
Distrib uto rs
2004
Dec 0 5
Fin al Rule :
Imp ort/E xp ort
Co ntro ls
A ug 05
E ne rgy
P olicy Act 3
Dec 0 5
Incre ase d
Con trols 4
2 00 5
Ma terials
S e curity
A ssessme n ts
2005
2006
2006
1998 - 2003
D ev elopm ent of IAEA C ode of C onduc1 t
20 0 5
Up da ted
In terim
Da ta b ase
Future
Jul 0 5
Fina l Ru le :
P o rtab le Ga u ge s
Jul 0 5
NRC O rd ers:
RAMQ C 2
2007
Jun 0 7
Na tio na l So urce
Tra cking S yste m
2006
A p r 06
In itial Imp le me n ta tio n
o f P re -lice nsing
G uida nce
Aug 0 6
Fin al Rule :
Natio n al S ou rce
Tracking S ystem
*Courtesy of the Nuclear Regulatory Commission
2 0 06
Up da te d Inte rim
Data ba se
20 06
In crea se Me asu res
to V e rify A u th en ticity
of Licen se es/S h ip pe rs
2
20 0 7
W eb -ba se d
Lice n sin g
2008
De c 08
Fin a l Ru le:
E n h an ce d S e cu rity a t
Ma teria ls Facilitie s
U.S. Department of Energy
Alternatives to Industrial Radioactive Sources
Industry utilizes Category 1 and 2 sources based on their physical and/or economic attractiveness.
Some devices are very portable; others produce energy in lieu of available electricity, and still
others accomplish specific, beneficial purposes, like those in the medical arena. In the
construction industry, sealed sources are used to perform radiographic examination of
construction welds, while other sources are used to determine compaction and moisture content of
roadways. Sealed sources have economic value because they don’t require much power and can
be used in remote areas.
Most of the radioactive materials used in industrial sealed sources are man made; some result
from the fission of nuclear reactor fuel and others are produced in reactors by irradiation of
radioactive or non-radioactive targets. In addition, some radioactive materials are decay products
of natural uranium. These isotopes are then purified through a chemical or mass separations
process (the radioisotope differs from its target material and has to be separated from it. Appendix
D provides a listing of the IAEA Category 1 and 2 radionuclides of concern and how they are
produced.
Sealed sources are manufactured in relatively few countries, but because of their wide range of
applications, they are used the world over. Most sources considered high-risk (e.g., cobalt-60,
cesium-137) are produced in Canada and Russia. Other source-manufacturing countries include
Argentina, Hungary, India, and South Africa. Thus, developing technological alternatives will
mean working together with international partners, who will be key to a successful domestic
program.
2. Industrial Applications of Category 1 Radioactive Sealed Sources
Radioisotope Thermoelectric Generators (RTGs). RTGs produce power from radioactive decay
and are used as power sources in remote locations, e.g., light houses, and for military
applications. RTGs typically contain 30,000 to 300,000 Curies of strontium-90 contained in many
individual sealed sources. The use of strontium-90 was driven by several positive features,
including its large heat generation, long half-life, low cost, and decay by betaemission. Plutonium-238 is also used, but these units, much smaller and more expensive than the
strontium-units, are primarily for deep-space exploration. Because RTG’s are relatively large—
they can weigh between 800 and 8,000 pounds—they would be difficult to steal. Many RTGs in
the United States have already been replaced with alternative technologies, such as batteries and
solar cells. The remaining RTGs are located at DOE and DoD sites. The exception are those that
DOE provides to the National Aeronautics and Space Administration for deep space exploration.
These are shipped to NASA and temporarily stored pending launch. RTGs containing radioactive
material are still used in foreign countries, especially in countries with unreliable power sources.
They are used, for example, to power light houses in the former Soviet Union. Because they are
often located in remote areas, or in countries with less stringent controls, they remain a risk
factor.
Industrial Irradiators: Irradiators are used to kill living organisms (e.g., in sterilization of medical
instruments and blood, or food irradiation). They may be mobile or stationary and generally
contain hundreds of cobalt-60 “pencils” ranging from 100,000 to 5 million Curies, or cesium-137.
Large industrial irradiators are considered “self-protecting,” meaning that anyone attempting to
steal the radioactive material would get a lethal dose of radiation. Although some concern with
these devices could arise because of the need for transport to replenish them after decay, stringent
regulatory controls are in place to protect the material. Facilities that house the equipment also
have strict regulatory controls. For security purposes, cobalt-60 is preferred over the use of
cesium-137 in irradiators. In addressing security concerns, the use of Cobalt-60 is recommended
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U.S. Department of Energy
Alternatives to Industrial Radioactive Sources
and should be encouraged over the use of cesium-137. Cobalt requires more shielding, thus
making the device large, heavy, and difficult to move and is more expensive to the user thus
making it attractive for recycling and reuse.
Mobile Irradiators. Mobile irradiators are another class of industrial device; however, they are not
licensed for use in the United States. Typically, they are used in countries with large amounts of
fresh fruits and vegetables that need irradiation to prolong shelf life. Examples are seed
irradiators, which are usually mounted on large trucks or trailers for transport to irradiate seeds
during planting. Mobile irradiators can contain approximately 3500 Curies of Cs-137, however,
because of the size of the irradiator they would be difficult to steal; of more concern is the
possibility that they would be abandoned. These devices are considered self-shielded because
their massive design (each can weigh 10-67 tons) incorporates heavy shielding, which makes the
sources difficult to extract; however, the abandonment of these devices is of concern.
Research Irradiators. Research irradiators are generally smaller than industrial irradiators and
usually contain sealed sources with cesium-137 because cesium requires less shielding than
cobalt-60. These types of irradiators are good candidates for replacement with an alternative
technology as they are often times more vulnerable than industrial irradiators as less shielding
means less mass and also because the types of facilities where they are located may not have
effective security.
3. Industrial Applications of Category 2 Radioactive Sealed Sources
Radiography. Radiography cameras use gamma rays to image and measure sophisticated
construction processes, including the integrity of welds. Most new radiography cameras use
iridium-192 or other radionuclides, though cobalt-60 and cesium-137 are also used. The choice of
radionuclide depends on the application, e.g., Cobalt-60 can effectively penetrate very thick
materials, while the other radionuclides can inspect plastics and very thin or low density
materials. The chief concern for these heavily shielded devices, as for Category 1 mobile
irradiators, is abandonment.
Fixed Industrial Gauges. Nonportable gauging devices (gauges mounted in fixed locations) are
designed to measure or control such things as material density, flow, level, thickness, or weight.
They contain a gamma-emitting sealed source, usually cesium-137, or a sealed neutron source,
usually americium-241 and beryllium, and radiate through the substance being measured to a
readout or controlling device. Generally small and connected to process control equipment,
they’re not easily recognizable, which could result in loss of control should the facility modernize
or shut down.
4. Sources Used For Well Logging
Well logging gauges determine the characteristics of underground formations to predict the
commercial viability of a new or existing oil or gas well. The gauges measure certain properties
of an underground formation, such as type of rock, porosity, hydrocarbon content, and density. In
oil well logging, the data give benchmark measurements which are then compared with
measurements made in other ways to help find formations likely to contain hydrocarbons.
Although americium-241 and cesium-137 are the most often-used sources, the size of the source
depends on the specific tool function and design, i.e., sources of the same isotope but of lesser
activities are used for shop and pre- and post- job tool calibrations.
There may be five to ten thousand sources in use performing neutron activation analysis and other
diagnostics, with many containing a neutron source in the 15-20 Curie range. Well logging
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U.S. Department of Energy
Alternatives to Industrial Radioactive Sources
sources also typically use a cesium-137 gamma source in the tens of Curies for a simultaneous
density scan. Well logging units, highly mobile and easily moved from site to site, are vulnerable
for theft. Recent technological advances have included logging-while-drilling, which furnishes
real time data during drilling operations and improves the evaluation of geologic formations
while reducing drilling costs. The real-time information support decision making, because
evaluation can start as soon as the drill bit reaches a formation.
Before 1987, well logging tools were traditionally lowered into a well on a wireline. Information
collected by the detectors reached the surface through the wireline and was plotted on a chart as
the logging tool slowly rose from the bottom of the well. This meant drilling had to stop while
parts of the rig were removed before a well logging tool could be inserted. More recent
technology allows well logging to be accomplished during drilling. This technology, called
“logging while drilling,” requires attaching the neutron source to the drill bit. The drilling
industry has implemented this alternative to replace traditional well logging sources and has
investigated replacing the traditional type of isotope used with a deuterium-tritium (D-T) source.
The D-T uses a small accelerator to drive a fusion reaction to create neutrons. The Energy
Compensation Sources (ECS) calibrates the well logging tool while the well is being drilled. The
D-T sources cannot sustain the stress from this type of operation; however a sufficiently large
americium/beryllium source performs satisfactorily in this manner.
Tritium neutron generators (tritium sources within a neutron generator tube) are also used for well
logging applications. These devices, which determine the porosity and permeability of reservoir
rock formations, are used as traditional well logging tools (drilling is stopped before the tool is
lowered) and are not suitable for logging-while-drilling. These sources used are less hazardous
than americium and cesium sources because they produce a neutron stream only when power is
applied; meaning the user can’t use them without an available power source.
Logging-while-drilling furnishes real-time data, improves the evaluation of geologic formations,
and reduces costs. In April, 2000, the NRC, noting the relatively low activity (50 micro Curies) of
the ECS as compared with traditional well-logging sources (3 – 20 Curies), revised its regulations
on the use of the ECS, which are used in the logging-while-drilling process, to 100 micro Curies.
Well logging sources present a unique set of problems, and the use of several Curies of any
transuranic alpha emitter in a source that is easily transportable raises concerns. When it isn’t
practical to substitute D-T sources for large Am Be sources, an alternative to Amercium-241
should be considered. If the oil exploration industry could work with a 1 MeV monoenergetic
neutron source, a couple of viable gamma emitters are available. The primary improvement
would be a source that decays to insignificance in a decade or two instead of centuries.
Table 1-1 Description of Applications and Numbers of Category 1 and 2 Units at NRCLicensee Facilities
Application
Radionuclides
Activity Range
No. of
(Category 1 and 2)
Units**
Power Sources
Strontium-90
3,000 Ci – 244,000 Ci
34
Plutonium-238
85,000 Ci – 570,000 Ci
(RTGs)
Industrial and
Cobalt-60
300 Ci – 40, 000 Ci / source
550
Research
Cesium-137
27 Ci – 213,000 Ci
794
Iridium-192
22 Ci – 330 Ci
1903
Measuring
Americium-241
20 Ci to 50 Ci
18
Americium-beryllium
16 Ci – 44 Ci
296
Devices
Plutonium-238
38 Ci – 50 Ci
7
*NRC 2005 Interim Inventory Data - IAEA Category 1 and 2 sources regulated by NRC
**The RTGs are located at military installations.
5
Alternative.
Tech. Exist
Yes
No
Some
Some
U.S. Department of Energy
Alternatives to Industrial Radioactive Sources
5. Current Domestic and International Programs to Manage and Dispose of
Radioactive Sources
5.1 Domestic Efforts to Establish and Manage Radioactive Sealed
Source Inventories
Recognizing the need for tighter security for radioactive sealed sources, in July 2002 the DOE
and NRC formed an interagency Working Group to address the vulnerabilities, protection, and
control of sources that could be used in RDDs. The Group’s report, “Radiological Dispersal
Devices: An Initial Study to Identify Radioactive Materials of Greatest Concern and Approaches
to Their Tracking, Tagging, and Disposition,” addressed four areas: (1) defining the relative
hazards of radioactive materials and identifying the radioisotopes of concern; (2) analyzing
options for developing a national source tracking system (NSTS); (3) identifying technological
methods for tagging and monitoring sources; and (4) facilitating the final disposition of
unsecured, excess, and unwanted sources. The report recommended a national-level system for
the inventory and tracking of high-risk sealed sources. It also recommended that the NRC and
DOE establish interim inventories of their Category 1 and 2 radioactive sealed sources until the
national system is implemented.
In addition to the DOE/NRC activities, the international community, through the IAEA, also
addressed source security in its Code of Conduct on the Safety and Security of Radioactive
Sources[the Code], and its related Export and Import Guidance on Radioactive Sources. The
United States has made a political commitment to the IAEA to work toward following the
guidance in the Code, which includes establishment of a “national registry.”
5.1.1 Regulations Governing Sealed Sources
Regulations on the possession, use, receipt, transfers, and disposal of radioactive materials in the
United States is granted to multiple Federal agencies.
The Atomic Energy Act grants authority to regulate radioactive materials to DOE and NRC and
establishes the types and uses of radioactive material for which the authority has been granted.
DOE and NRC promulgate and enforce regulations for governmental and commercial use of
these materials. DOE establishes radiation protection standards and program requirements for
protecting people from ionizing radiation resulting from DOE activities. NRC establishes licenses
for persons to receive, possess, use, transfer, or dispose of byproduct, source or special nuclear
materials. Except for nuclear reactors, the NRC may transfer regulatory authority for these
materials to ‘Agreement States,’ as long as the states can assure NRC they have compatible
regulatory programs.
Other Federal agencies regulate specific applications, devices, containers, shipment of radioactive
materials, and limits on radioactive materials released to the environment. Regulations are further
described in Appendix E.
The Energy Policy Act of 2005 requires the establishment of a National Source Tracking System.
Before the Energy Policy Act, no Federal legislation or regulations existed to require routine
reporting of radioactive sealed source inventories to a central repository. To close the gap in
reporting requirements, NRC is revising its regulations via the Federal Register Notice (FRN)
process and has issued its proposed Rule, National Source Tracking of Sealed Sources, which
establishes a national source registry and tracking system (NSTS) for transaction-based reporting
of select sealed source materials. Each time a Category 1 or 2 sealed source is sent or received by
a licensee, NSTS will receive a transaction report.
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U.S. Department of Energy
Alternatives to Industrial Radioactive Sources
The DOE has Environment, Safety, and Health (ES&H) regulations that include an inventory
verification of radioactive sealed sources; however, no requirement exists for tracking the sealed
source or reporting results to a centralized system. The annual inventory requirement for
accountable radioactive sealed sources is covered under Title 10 of the Code of Federal
Regulations, Part 835, Occupational Radiation Protection. But to work in concert with NRC and
prepare to include DOE data in the national system, DOE is also drafting a directive to define its
NSTS reporting requirements, including transfers of Category 1 and 2 radioactive sealed sources
to and from NRC licensees.
5.1.2 Development of a National Source Tracking System (NSTS)
In 2003, after the DOE/NRC Working Group report was issued, NRC began to develop and
implement sealed radioactive source tracking regulations and to design the business case for the
NSTS. Recognizing the need for the NSTS to serve many Federal agencies, NRC enlisted their
support and help in developing the system. The NRC also solicited input from the 2,500 or so
commercial, academic, medical, and governmental entities licensed by NRC or its Agreement
States and who may own and/or transfer radioactive sources of concern.
The NSTS is being designed to give a life cycle account of each high-risk source.
Licensees would be responsible for most of the system's input. Some of the main users and
transactions include:
•
•
•
•
•
•
Manufacturers would record source creation, shipment, and receipt of spent sources.
Licensees who use the materials would record source receipt, shipments to a vendor or
disposal facility, request to import sources or export to a foreign recipient, and storage-intransit.
Disposal facilities would record source receipt, disposal, or other long-term disposition.
All licensees would perform periodic physical inventories, record the results, and report
loss or theft.
Customs officials would use the system to validate imports against licensee requests for
import from a foreign vendor.
Other government agencies might use the system to gain information on materials at
licensee locations or in transit.
The benefits of a national system are:
•
Better accountability for the movement and possession of materials, which could help
deter and detect source loss or theft. For example, the system would allow automatic
alerts on sources that are shipped but not recorded as received. This information would
allow follow-up action to verify materials security.
•
An import/export notification report will be developed as one of the routine reports in the
NSTS and provided to Customs. Customs, however, is not expected to have direct access
to the information in the NSTS.
•
Better information for decision-makers to use to assess hazards posed by these materials
in terms of actual movement, storage, use, and final disposition.
When fully deployed, the NSTS will carry information on radiation sources owned by NRC,
Agreement State licensees, and DOE. The system won’t have information on Department of
Defense radiation sources unless they’re owned under a NRC license.
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5.1.3 DOE and NRC Data Calls for Interim Inventories
Since the NSTS isn’t expected to be operational until mid-2007, the DOE and NRC have
established interim annual inventory data calls. Table 1-2 provides the 2005 DOE and NRC
inventories by IAEA Category 1 and 2 radionuclides.
The NRC data call collects information relevant to commercial licensees. The data call assigns
each source to a specific license and includes licensee information, isotopic data, and source data
(model numbers, manufacture serial numbers) for Category 1 and 2 quantities of materials using
the IAEA Categorization model. The isotopes reported are americium-241, americium/beryllium,
californium-252, cobalt-60, cesium-137, iridium-192, plutonium-238, plutonium-239/beryllium,
selenium-75, and strontium-90.
The DOE data call collects information on individual sealed sources subject to Title 10 Code of
Federal Regulations (CFR) 835, Subpart M-Sealed Radioactive Source Control and the guidance
in DOE Guide 441.1-13, Sealed Radioactive Source Accountability and Control Guide. This data
call includes information on model numbers, manufacturer serial numbers, as well as the location
(building and room number) of the source and whether or not the source has a known disposition
path (primarily to account for nuclear materials in the DOE complex that would require recovery
and disposition at some time) and also the source status (in use or not in use).
Although the NSTS will help detect theft and make the user more source-accountable, the system
cannot by itself guarantee the physical protection of high-risk radioactive sealed sources or
preclude theft. The NSTS will provide an additional tool to be used in conjunction with other
security measures and controls.
5.1.4 Radioactive Sealed Sources and the Department of Defense
Four branches of the military—Air Force, Army, Navy Marines—use sources for ionizing
radiation. Examples include linear accelerators, cyclotrons, radiofrequency generators, and other
electron tubes that produce x-rays. These devices and processes use plutonium or enriched
uranium, thorium, by-product material, or naturally occurring or accelerator-produced radioactive
materials, such as radium. The military has radiation control programs and regulations to manage
and control its sources.
Each branch of the military is licensed by the NRC to receive, own, distribute, use, transport,
transfer, and dispose of radioactive material. The license is either a Master Materials License,
authorizing the use of byproduct material in any form and as needed, or limited to some
maximum quantity, or an NRC-specific license issued to a single specified applicant as in a
specific Army installation. As an NRC licensee, the Department of Defense is expected to
participate in the NSTS and report its inventory of “nationally tracked” sources under the
proposed NRC Rule.
5.1.5 U.S. Department of State
The U.S. Department of State (DOS) has primary responsibility for coordinating
U.S. participation in various international efforts, including the safety and security of radiological
materials. The DOS is the lead agency, and manages the distribution of resources for, interagency
and international coordination on nonproliferation and security. The DOS is working to find and
secure dangerous orphan sealed sources and to help some other countries do the same. In
interactions with key international organizations, such as the IAEA, the DOS encourages the use
of alternatives to radioactive sealed sources. DOS also works with other international partners,
including the International Source Suppliers and Producers Association, on adequate management
of sources throughout their life cycle and to promote international harmonization of export and
import controls.
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Table 1-2. Radioactive Sealed Source Inventories for Category 1 and 2 Radioisotopes per 2005 NRC
and DOE Agency Data Calls (empty cells indicate none)
Amounts Listed in Curies
Isotope
IAEA
IAEA
Category 1
Threshold
Limits
(Curies)
Category 2
Threshold
Limits
(Curies)
NRC
No. of Units
DOE
No. of Units
1
NRC
DOE
No. of Units
No. of Units
20
18
21
Am-241
2000
Am-241/Be
2000
20
296
Cf-252
500
5
1
Cm-244
4
2
Co-60
800
22148
18
8
18399
98
Cs-137
3000
233
1329
30
1109
48
Gd-153
30000
Ir-192
2000
20
1903
0
0
20
13
112
1
20
1
5
300
1
Pm-147
Pu-238
2000
Pu-239/Be
2000
5
Ra-226
1
Se-75
5000
Sr-90
30000
0
50
4
24
271
300
10
341
22411
1620
21754
632
Tm-170
Yb-169
totals
5.2 International Efforts to Establish and Manage Radioactive Sealed
Source Inventories
The IAEA, through technical symposia and training, promotes collaboration among
international partners to identify gaps and strengthen radioactive materials controls.
The IAEA Code of Conduct (“the Code”) on the Safety and Security of Radioactive Sources
furnishes guidance for the safety and security of radioactive sources. In September 2003 the Code
was revised to better address security concerns associated with radioactive sealed sources;
published in January 2004, it has garnered the commitment 80 foreign states, including its
supplemental guidance on the Import and Export of Radioactive Sources. The Code advocates
international cooperation in development of regulations and controls that would enhance the
safety and security of radioactive sealed sources during transfers and within and between member
states. The IAEA recommends that each member state (i) Achieve and maintain a high level of
safety and security of radioactive sources; (ii) Prevent unauthorized access or damage to, and
loss, theft or unauthorized transfer of, radioactive sources, so as to reduce the likelihood of
accidental harmful exposure to such sources or the malicious use of such sources to cause harm to
individuals, society or the environment; and (iii) Mitigate or minimize the radiological
consequences of any accident or malicious act involving a radioactive source. In addition, the
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Code calls for member States to establish a national register of Category 1 or 2 radioactive
sources. To help member states, the IAEA offers its Regulatory Authority Information System
(RAIS) database, a management tool for documenting and consolidating information on
regulatory controls of radiation sources. RAIS lets regulatory authorities do the daily work of
sealed source management. The database contains inventories and detailed records on every
radiation source, including licenses, registrations, and information on the facility where the
source is used. The IAEA also sponsors education and training to develop and sustain a trove of
the skills, knowledge, and expertise of the scientists, legislators, regulators, politicians,
administrators, and employees in facilities that use radioactive sources.
The Code and its Annex, “Categorization of Radiation Sources,” identifies 26 radionuclides
and threshold activities as sources of high risk or concern. The categorization is based on Dvalues, which provide the basis for determining how dangerous a source is. The United States
will work toward following this categorization in developing requirements for its NSTS and
also for developing regulations and policy on radioactive sealed sources.
5.2.1 Export/Import Controls
International controls are essential in life-cycle management of radioactive sources, including
their import and export. After the Code was signed in September 2003, the international
community felt that the import and export of radioactive sources was an area where controls
needed to be strengthened. Accordingly, the IAEA developed “Guidance on the Import and
Export of Radioactive Sources.” Together, these documents outline recommendations on the roles
and responsibilities of entities engaged in both the import and export of commercial sources, to
ensure they’re managed safely and securely and to help prevent malicious use. The import/export
guidance seeks to harmonize multilateral interactions and, as of May 2006, 83 States have made a
political commitment to follow the Guidance.
The United States has made a political commitment to work toward following the IAEA
import/export guidance, and with interagency coordination, will continue to promote international
harmonization.
6. Domestic Disposal Options for Radioactive Sources
To protect the public, workers, and the environment from the release of radioactive sources, it is
important to consider the disposition of disused sources. This section discusses our domestic
disposal system for radioactive sources, including governing laws, disposal requirements,
available disposal options, ongoing disposal initiatives, and financial surety requirements.
Low-Level Radioactive Waste (LLW)
The DOE manages the disposal of DOE sealed sources through procedures comparable to NRC
regulations. These sources are classified according to waste type as either low-level radioactive
waste (LLRW) or transuranic waste. Under the Low-Level Radioactive Waste Policy
Amendments Act (LLRWPAA) of 1985, DOE disposes of its sources at DOE radioactive waste
disposal facilities in accordance with DOE policies and orders. DOE is also responsible for the
disposal of LLRW owned or generated by the U.S. Navy resulting from the decommissioning of
naval vessels, LLRW owned or generated by the Federal government as a result of any research,
development, testing, or production of atomic weapons, and for any LLRW exceeding the Class
C limits (i.e., greater-than-Class C or “GTCC”) from activities licensed by NRC. DOE has
LLRW disposal facilities at the Hanford Site in Richland, WA; Idaho National Laboratory in
Idaho; the Nevada Test Site in Nevada; the Los Alamos National Laboratory in New Mexico; and
the Savannah River Site in South Carolina. Most of these sites may accept waste only from onsite
generators.
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The types of sealed sources disposed of at DOE facilities are similar to those used by commercial
industry, such as Am-241, Pu-238, Pu-239, and other actinide sources used for imaging and
measurement (e.g., radiography cameras, well logging, and calibration); Co-60, Cs-137, Sr-90,
and other beta/gamma sources used in irradiators (for therapy or sterilization) and in power
sources (e.g., radioisotope thermoelectric generators); Pu-238/beryllium neutron sources used in
level gauges and other devices; and radium-226 and other miscellaneous small sources used to
support DOE mission activities.
Greater than Class C Waste
Under the LLRWPAA, DOE is responsible for disposal of commercial GTCC at an NRClicensed facility, but because such a facility doesn’t exist, NRC regulations require that GTCC
sources be disposed of in a geologic repository, unless it approves an alternative disposal method.
DOE has started to prepare an environmental impact statement (EIS) to analyze disposal
alternatives for GTCC LLRW. The scope would include disposal capacity needed for current and
projected GTCC LLRW, including GTCC sealed sources, generated by NRC and Agreement
State licensees. EPA is participating in the EIS as a cooperating agency.
As required by the Energy Policy Act of 2005, DOE will submit a report to Congress in fiscal
year 2006 on the estimated cost and proposed schedule to complete the EIS. Section 631 also
requires that, when the EIS is done, DOE will report to Congress on the disposal alternatives and
wait for Congressional direction before implementing a decision. The time required to build and
license a new facility, or to modify and license an existing one, is unknown. And some
alternatives may require Federal legislation to implement. Finally, existing policies don’t include
the disposal of non-DOE sources from commercial generators at DOE facilities.
Transuranic Waste
The Waste Isolation Pilot Plant (WIPP) Land Withdrawal Act, PL 102-579, and the EPA 1998
Certification Decision authorize DOE to dispose of transuranic waste generated by atomic energy
defense activities at WIPP, an underground repository near Carlsbad, New Mexico. DOE is
required to operate WIPP in accordance with EPA regulations for high-level waste (re:
40CFR191 and 40 CFR194). NRC doesn’t use the classification “transuranic”; what to DOE is
transuranic waste is GTCC to NRC.
Low Radioactivity Sources
The EPA Clean Metals Program addresses common sources that, because of their lower
radioactivity, are not considered IAEA Category 1 or 2 sources. The Program works with the
metal processing and demolition industries to identify and properly dispose of sources detected in
the scrap metal recycling stream (e.g., improperly disposed of exit signs containing tritium may
contaminate water supplies and community water systems). Some states and the Conference of
Radiation Control Program Directors administer programs to recover and dispose of lower
activity sources. The EPA, under authorities in the Atomic Energy Act of 1954 (AEA), also
issues general environmental protection standards and radiation protection guidelines for some of
the facilities that dispose of sealed sources.
To increase awareness on the proper handling and disposition of found sources, the EPA works
with industries that may come in contact with lost, stolen, or abandoned sources. The scrap metal
and metal melting industries have reported over 4,000 radiation alarms, with 34 confirmed source
meltings. With the help of the scrap metal industry, EPA developed a CD-ROM training program,
“Responding to Radiation Alarms at Metal Processing Facilities,” to teach a standard protocol for
responding to these alarms. This program continues to be distributed to state radiation control
program officials and metal processing facilities worldwide. To prevent radioactive materials
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from ever being mixed in with the scrap metal, the EPA also developed a voluntary partnership
with the National Demolition Association, producing a CD-based training program entitled
“Identifying Radioactive Sources at the Demolition Site.” This material has become part of the
training programs of more than 800 U.S. demolition contractors.
In 2001, EPA conducted a pilot program with the State of Colorado to try to round up known, but
unsecured, orphan radioactive sources. During this pilot, 30 cesium sources were recovered and
returned to a source manufacturer for disposition at a cost of $30,000. A legal template was
developed for states to use during future roundups. This pilot set the stage for the nationwide
roundup, currently ongoing, which is funded by the NRC and DOE.
From 1999 through 2005, the DOE Orphan Source Recovery (OSR) Program recovered 12,024
sealed sources comprised of six principal isotopes (Pu-238, Pu-239, Am-241, Cs-137, Sr-90 and
Co-60). The owners varied from individuals, small firms, or colleges having one source, to large
firms with hundreds. The OSR Program forecasts an FY 2006 recovery of 1,960 sources.
6.1 Disposal of Commercial Radioactive Sources
Three major factors affect disposal of commercial sources: restrictions associated with the
LLRWPAA, waste classification requirements, and cost.
LLRWPAA Restrictions
Under the LLRWPAA, states must provide disposal capability for commercial Class A, B, and C
LLRW, as defined by NRC regulations or comparable Agreement State regulations. The
regulations outline characterization, design, and construction requirements for new disposal
facilities and set requirements for facility operation, closure, post-closure, monitoring, and
financial surety.
The LLRWPAA encouraged regions to form compacts to handle the low-level radioactive waste
(LLRW) they generate. Two commercial disposal facilities (Barnwell, South Carolina, and
Richland, Washington) are operating. Barnwell serves the Atlantic Compact and 36 other states.
In June 2008, Barnwell will close to the non-Atlantic Compact states. The Richland facility
accepts waste from the Northwest and Rocky Mountain Compacts.
Another commercial LLRW disposal facility, in Clive, UT, accepts only Class A waste and is not
associated with a specific compact. Waste Control Specialists is in the licensing process for a new
commercial LLRW disposal facility in Andrews County, TX to serve the Texas Compact. A
licensing decision is expected after December 2007.
Waste Classification Requirements
Commercial radioactive sources are subject to waste classification requirements in 10CFR61,
Licensing Requirements for Land Disposal of Radioactive Waste (or comparable Agreement State
regulations). The NRC waste classification system imposes increased isolation based on the
material’s toxicity, longevity, and mobility. Class A, B, and C waste can be disposed of at
commercial disposal facilities, with increased restrictions associated with increased class. GTCC
waste is generally not considered appropriate for disposal at one of these facilities. As mentioned
earlier, DOE is responsible for the disposal of GTCC LLRW. Many, if not most, Category 1 and
2 sources would be classified as GTCC because of their relatively high radioactivity. Some Class
B/C sources don’t meet existing commercial disposal facility criteria and thus, like GTCC
sources, have no disposal path.
Disposal Cost
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Disposal cost at commercial facilities is a function of volume, weight, and radioactivity. Sources
are often physically very small with a relatively high radioactivity per unit volume or mass.
Often, to meet disposal criteria, small sources must be encapsulated in an inert, stable medium
such as concrete, which significantly increases disposal weight and volume while radioactivity
remains the same and may result in a disposal cost in the tens of thousands of dollars. High cost
can be a big disincentive to proper disposal of disused sources, even prohibitive for some
licensees. These sources may therefore remain in storage indefinitely, which could lead to
abandonment, misuse, or theft absent other disposition alternatives, such as recycling or reuse.
While NRC policy favors disposal over long-term storage, it sets no time limits on storage if the
material is being safely and securely managed. But even though a stored source is still subject to
NRC regulations, permanent disposal in a licensed facility is inherently more secure than
indefinite storage by the licensee.
From licensees holding byproduct material at activity levels above certain thresholds, NRC
regulations require financial sureties or a decommissioning funding plan. For sealed sources, the
thresholds are fairly high and only affect possessors of individual IAEA Category 1 sources or
significant quantities of lower activity sources; small quantity possessors don’t have to have
financial assurance. Possessors without funds set aside to cover the costs of disposal or other
appropriate disposition must leave their sources in prolonged storage, unfortunately subject to
possible misuse or abandonment.
6.2 Excess, Unwanted, and Orphan Sources
Tracking Missing Sources
NRC/Agreement State regulations aim at preventing radiation exposure to workers and the
public. Preventing theft and accidental loss of sources, including those in storage, is one goal of
the overall safety requirements. NRC’s main way of controlling and recovering lost and stolen
sources is through regulations and enforcement. Licensees must report lost, stolen, or missing
licensed material exceeding specified quantities within time frames ranging from immediate
notification to 30 days after the occurrence. The notification process lets the NRC/Agreement
State take appropriate action to recover the source and to protect public safety and security, based
on the source and the circumstances. All reported events are recorded in the Nuclear Materials
Events Database for occurrences under the purview of the NRC or an Agreement State. A
General Tracking System, which focuses on Category 3 or lower is used for tracking individual
devices and sources. A database is being developed that will track sources with higher
radioactivity.
When lost or abandoned radioactive material is found, NRC can try to find the owner but is
prohibited from taking possession of the material. When the owner can’t be found, isn’t licensed
to possess the material, or can’t resume possession, NRC relies on an Memorandum of
Understanding (MOU) with DOE or EPA to recover and disposition the material.
The availability of disposal options is thus a critical element in the development of alternative
technologies. If disused sources have no disposal path, they may become vulnerable to misuse,
theft, or transfer to nations with poor regulatory controls.
7. Transportation of Sources
The greatest vulnerability of a radioactive source to loss or theft occurs during transportation.
NRC recently implemented new security measures and coordination for Radioactive Material
Quantity of Concern (RAMQC) shipments. The objective of these requirements is to ensure
timely detection of any loss or diversion of shipments containing Category 1 quantities of
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radioactive material. When licensees use contract carriers, they must seek reasonable assurance
that the carrier meets certain additional security requirements. If the carrier has a tracking and
security plan that the U.S. Department of Transportation (DOT) requires for shipments of
highway route quantities of radioactive material, the licensee shall verify and document that the
carrier’s tracking and security plan meets all NRC requirements, or get written confirmation that
the carrier will implement these provisions. Licensees must notify the NRC Operations Center in
advance of shipment dates for all radioactive material above Category 1 quantities.
The NRC has Additional Security Measures (ASMs) for transportation of
RAMQC. Shipping and tracking information on all RAMQC shipments, including the isotopes
and quantities, consignees and consignors, routes, carriers, schedules, and points of contact, is
supplied to and updated by the NRC daily. This information is shared with other agencies and
authorities on a “need to know” basis.
8. Research and Development Program Plan
Although improvements in physical security and regulatory controls can reduce the risks that
radioactive sealed sources could be used in RDDs, a significant factor contributing to the problem
is the widespread use of these materials. Each industrial application using radiological source
material needs to be evaluated to identify suitable potential alternative technologies and plan for
research and development that can bring them into fruition. The general approach to fostering the
research and development of alternative technologies to reduce risks associated with the handling
use and storage of large sealed sources will focus on three objectives:
•
•
•
Replace radioactive source isotopes with technologies that do not use radioactive materials.
Reduce the effectiveness of sealed sources in harming populations and disrupting
infrastructure.
Prevent the theft or decrease the recovery time of sealed sources.
The details of the research and discussions of various technologies are provided in Part 2 of this
report
Impact of adopting alternative technologies:
Once the alternative technologies become available, Figure 2 describes a possible process for
evaluating and adopting these technologies and the potential impact of this process on the current
inventory of sealed sources.
•
First a sealed source would be evaluated to determine if a non-radioactive alternative is
available. If an alternative is available, its adoption could be encouraged with financial
incentives. If the alternative was adopted, the sealed source would become surplus and
either disposed of or placed in interim storage while awaiting disposal.
•
If a non-radioactive alternative was not available, the applicability of (1) a less harmful or
dispersible alternative source or (2) a source or device containing a source with integrated
security features would be evaluated. These improved sources can be considered RDD
resistant. If a RDD resistant source could replace the existing source, its adoption could be
encouraged with financial incentives. If the alternative was adopted, the disused sealed
source would become surplus and either disposed of or placed in interim storage while
awaiting disposal.
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Figure 2: Process for Evaluating / Adopting Alternatives
Outcomes
Current
Status
At Risk
Inventory
(Isotope and
application)
Nonradioactive
alternatives
to existing
source exist
Yes
RDD
Resistant
Inventory
No
Alternative
Sources
Less harmful
alternatives to
existing source
exist
Yes
Encourage
alternative
use with
incentives
Disused
Sources
No
Alternative
sources with
integrated
security
features exist
Interim
Storage
Disposition of
sources
displaced by
alternatives
Yes
Disposal
At Risk Inventory
Decreased
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With regard to the existing inventory of sealed sources in the United States, the expected
outcomes of adopting alternative technologies are:
•
The total number of sealed sources will be reduced because of adoption of technologies that
do not use radioactive materials.
•
Sealed sources remaining in use will have features that make them RDD resistant
•
Sealed sources replaced by non-radioactive technologies or by RDD resistant sealed sources
will either be disposed of or placed in safe secure interim storage locations while awaiting
disposal
As one can see, the development and use of alternative technologies may not mitigate all
vulnerabilities associated with sealed sources. Disused sources could be donated or sold to a
foreign country with less controls, and disused sources would require storage until a disposal
path has been identified. In addition, a thorough cost/benefit analysis should be conducted to
determine whether or not the alternative would be attractive to the end-user. To ensure
alternatives technologies are considered for use by industry, the Federal government may need to
establish incentives for manufacturers and users, including bearing the cost of disposal, to reduce
vulnerabilities and address the RDD risk.
9. Legislative Recommendations
Any additional legislation for the control and management of radioactive sealed sources requires
multi-Federal agency buy-in. The NRC Radiation Source Protection and Security Task Force is
addressing recommendations both for Congressional action and Federal agency action or
considerations to address deficiencies. Their report will be transmitted to Congress and the
President August 7, 2006.
In addressing legislative recommendations for the development of alternatives, the Task Force
recommends the U.S. government should consider legislation for economic incentives to
encourage use of alternative technologies. If an alternative exists and is economically feasible,
these incentives could encourage end use. Incentives could include tax breaks, to encourage
transfer to the new technology, or incentives to help offset the disposal costs for the disused
source. The Office of Nuclear Energy endorses this recommendation as a means to foster the
adoption of alternative technology use.
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Part 2: Research and Development Plan for Alternative Technologies
1. Background
Section 957 requires the Secretary of Energy to establish a research and development program to
develop alternative technologies to replace the use of radioactive sealed sources. The goal is to
reduce the availability of radioactive sealed sources that pose health and safety concerns and/or
could be a proliferation risk. Section 957 makes reference to particle accelerators for well logging
and other industrial applications, and portable accelerators that produce short-lived radioactive
material at industrial sites. This Research and Development Program Plan will focus on those
and other technologies.
A research and development program plan for alternate technologies to radioactive sealed sources
should include several key pieces of information: the general uses of the radioactive sources in
industry; the vulnerability of the sources, including an assessment of risks to both health and
safety and security; and, the cost/benefit and assessment of whether the identified project is
economically viable and desired by end users.
Specifically, the plan should consider non-radioactive alternatives to using radioactive materials
as one option. This can be achieved by either (1) replacing the source with radioactive material
with a non-radioactive source, or (2) changing the process requiring radiation to one that does not
need radioactivity to produce results.
Where there are no technically or economically feasible alternatives, the plan should focus on
either making the sealed source less harmful to humans and more resistant to damage or
dispersion or making the radioactive sealed source more difficult to steal and easier to track,
should it be stolen.
The DOE anticipates two potential challenges to persuading industry to replace their sealed
sources with technically viable alternatives. First, as noted earlier, some radioactive sealed
sources have no approved disposal option or disposal is cost-prohibitive to the user. Second, the
alternatives may not be economically desirable, for reasons other than disposal costs. So, in
addition to funding research and development, the U.S. government should consider legislation
for economic incentives to encourage use of the developed and proven alternative technologies.
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2. Current Status
In order to identify the radioactive sealed sources that are considered of greatest concern, the
DOE used inventory data from the NRC 2005 Data Call for Category 1 and 2 sources.2 The
NRC data call provides a listing of Category 1 and 2 sealed sources as well as their use by the
NRC licensee3 (see Table 2-1.) Although the DOE has similar inventory information, the
majority of DOE Category 1 and Category 2 sealed sources are in storage pending disposition in
secure locations and are not identified by use.
Section 957 requires that alternative technologies be identified that could replace “large”
radioactive sealed sources. For the purpose of this report, “large” is defined as Category 1 and 2
sealed sources based on IAEA categorization (see Appendix B). In addition, Section 957 also
mandates consideration of well logging sources as one class of large radioactive sources. The
DOE and NRC inventories provide the number of Category 1 and 2 sources currently in use in
civilian industry and government programs. The inventories also provide critical information on
the number of Category 1 and 2 sources that can be examined for replacement with alternative
technologies. Additionally, these inventories provide a significant aide to the Department’s
research and development program’s ability to identify industries where there are a significant
number of sources in use and where sources may be most vulnerable to terrorists. More detailed
information on the sealed sources used in industry is provided in the first part of this report.
3. Proposed Research and Development Plan
3.1 Objectives
The general approach to fostering the research and development of alternative technologies to
reduce risks associated with the handling use and storage of large sealed sources will focus on
three objectives:
•
Replace radioactive source isotopes with technologies that do not use radioactive materials:
This is the primary objective of the research and development plan. Reducing the number of
sealed sources is the most effective way to reduce all risks associated with sealed sources.
The use of non-radioactive applications would significantly increase worker safety by
completely removing a source of ionizing radiation from the work place as well as greatly
limiting the availability of radioactive sources that might be used for criminal or terrorist
activity.
•
Reduce the effectiveness of sealed sources in harming populations and disrupting
infrastructure: This objective is intended to address situations in which the number of
radioactive sources or the industrial use of these radioactive sources does not have a
technically or economically feasible non- radioactive alternative. This approach would
reduce (1) the ease with which and source can be dispersed, (2) the hazard to humans, or
(3) the difficulty of clean up should the sealed source be used in a RDD. These sealed
sources would be considered RDD-resistant.
2 IAEA Category 1 and 2 sources are defined in Appendix B.
3 To be licensed to use nuclear materials or operate a facility that uses nuclear materials, an entity or
individual submits an application to the NRC. The Staff reviews this information, using standard review
plans, to ensure that the applicant’s assumptions are technically correct and that the environment will not be
adversely affected by a nuclear operation or facility.
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•
Alternatives to Industrial Radioactive Sources
Prevent the theft or decrease the recovery time of sealed sources: This object is intended to
address situations for which either non-radioactive or RDD resistant alternatives to existing
sealed sources are not feasible. Reducing the likelihood of the theft or the recovery time of
sealed sources will reduce the chances a sealed source can be used to harm the US population
and disrupt the infrastructure.
3.2 Challenges (non technical)
The DOE identified at least two potential challenges to persuading industry to replace their sealed
sources with technically viable alternatives:
First, The alternatives may not be economically desirable (not counting disposal costs for
existing sealed sources). Thus, adoption of alternative technologies may not be effective unless
economic incentives are established to encourage the adoption of those alternatives.
Second, as noted in part 1 of this report, some radioactive sealed sources do not have an approved
disposal option. Also the source may have an approved disposal option; however, the disposal of
the sealed source may be cost-prohibitive to the current user. The lack of an approved disposal
path for the sealed source or the costs of source disposal may prohibit industry from adopting any
new technology.
3.3 Anticipated Outcomes:
With regard to the existing inventory of sealed sources in the United States the intended outcomes
of the proposed research and development program are:
•
The total number of sealed sources will be reduced because of adoption of technologies that
do not use radioactive materials.
•
Sealed sources remaining in use will have features that make them RDD resistant.
•
Sealed sources replaced by non radioactive technologies or by RDD resistant sealed sources
will either be disposed of or placed in safe secure interim storage locations while awaiting
disposal.
The results of the technologies resulting from the proposed research and development plan are
shown in Table xx.
4. Details of Research and Development Plan
4.1 Utilize Technologies That Do Not Require Radioactive Isotopes
In developing its research and development program plan, the DOE identified industries and
applications where the radioactive sealed sources could be replaced by technologies that do not
utilize radioactive isotopes. This objective can be achieved in two ways, either (1) replace the
source of radioactive material with a non-radioactive source or (2) change a process requiring
radiation into one that does not require radiation.
Use of Non-radioactive Sources
The first approach has been successful used in the United States in replacing cobalt-60 radiation
sources in cancer therapy with linear accelerators that produce high energy x-rays. Additionally,
the U.S. Department of Agriculture has studied the technical and economic feasibility of using xray sources as alternatives to cobalt-60 and cesium-137 in food irradiators. Industrial electron
accelerators can use a steady electric field (direct current), a varying electric field
(radiofrequency), or linear induction, which uses a series of magnetic switches to accelerate
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electrons. While direct current accelerators’ very limited penetration restricts their use to thin
streams of food or liquid, radio frequency linear accelerators can deliver a more uniform dose of
radiation at different depths and have already been used to process food and sterilize medical
devices. The study noted that converting high-energy electron beams to x-rays increases their
penetration. Currently, no industrial electron accelerators can operate for long in the x-ray mode,
but Atomic Energy of Canada is developing a high-powered machine, known as a pseudocontinuous wave accelerator, which the DOE is using to develop a pulsed induction linear
accelerator that may make x-rays a viable alternative for irradiating food.
Tritium neutron generators (tritium sources within a neutron generator tube) have replaced
americium beryllium sources for some well logging applications. These sources used are less
hazardous than americium and cesium sources because they produce a neutron stream only when
power is applied; meaning the user can’t use them without an available power source. These
devices, which determine the porosity and permeability of reservoir rock formations, are used as
traditional well logging tools (drilling is stopped before the well logging tool is lowered into the
bore hole). However more recent technology allows well logging to be accomplished during
drilling. This technology, called “logging while drilling,” requires attaching the neutron source to
the drill bit. Unfortunately, current neutron generators are not rugged enough to be mounted on a
drill bit. Because the “logging while drilling,” technique saves time and money, the adoption of
neutron generators by the oil exploration industry has been limited.
Although non-radioactive technologies have successfully demonstrated that radioactive sealed
source can be replaced in certain situations, research is needed to expand the applications of these
technologies. Specific areas of research would be (1) making neutron accelerators more rugged
to withstand the stresses in oil drilling operations and (2) making the radiation output of X-ray
sources more similar in energy and intensity to the types of sealed sources they would replace.
Use Of Processes That Do Not Utilize Ionizing Radiation
A second way to eliminate the use of sealed radioactive sources is to modify a process requiring
ionizing radiation into one that does not require ionizing radiation. (The type of radiation emitted
by radioactive material is referred to an ionizing radiation) For example, many industrial
processes use gauges containing radioactive material such as cesium-137 to determine thickness.
Recently lasers have been, successfully used in certain processes to replace cesium-137 gauges
for assessing thickness. In another area, various methods have been developed to replace
radiography cameras in a number of industrial settings.
The EPA has developed a robust program intended to foster the modification of processes that
use ionizing radiation to those that do not require the use of ionizing radiation. The EPA’s
Radiation Protection Division has been committed to reducing the number of incidences of
radioactive sources that fall out of regulatory control and enter into the public domain, and has
conducted a number of projects over the years. These projects include alternatives for fixed
gauging devices, radiography cameras and portable moisture density gauges. The efforts to date
have included demonstration projects for devices that are currently or near entering the market
place, validation studies, and research and development for concepts requiring future
development. Future areas of study are expected to include well logging devices.
In selecting candidate research projects, the EPA identifies a specific industry that would benefit
from a change to an alternative technology; surveys the application in an effort to determine if an
alternative to the sealed source is technically feasible and generate a request for proposal to the
research community.
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The EPA program works in concert with industry to identify likely alternatives to radioactive
materials and radiation generating devices that will provide the same or better technical
performance with an equivalent economic benefit. The EPA program originally focused on
environmental protection instead of security concerns; however, the current program addresses
both concerns by eliminating circumstances in which radionuclides could be accidentally or
maliciously dispersed into the environment. The EPA research indicates that users are interested
in available alternatives; however, it also indicates that the alternatives are very use-specific.
The EPA created an advisory board consisting of end users and Government and other
stakeholders to identify candidate projects as alternatives to radioactive sealed sources. The EPA
program is operating at a modest funding level, approximately $200K per year.
Because the EPA program is well established and firmly connected to industry, a cooperative
agreement between the DOE and EPA is recommended so that Federal resources could be shared
in the development of alternative technologies. To date, the EPA program has not focused on
Category 1 or 2 sealed sources. Accordingly, the scope of the EPA program would have to be
expanded to address these larger sources. The EPA process should serve as a role model for other
Federal research and development programs.
4.2 Replace Radioactive Isotope With Less Hazardous and Less Dispersible
Materials
Alternatives to radioactive sealed sources may not be either available or practical for some
industrial applications. In addition, current technologies are quite mature and have been
successful for a long time. Thus, alternatives may not be attractive to some end users. In these
cases consideration should be given to developing methods and technologies to that result in
sealed sources that contain less dispersible and/or less hazardous radionuclides.
Less Dispersible Sources
In the area of creating less-dispersible sealed source materials, the NRC has funded research to
determine whether or not cesium chloride or americium-beryllium could be made dispersion
resistant. Initial results of research performed at the Argonne National Laboratory using a nonradioactive form of cesium-chloride in a proprietary compound called Ceramicrete showed
improved strength and enhanced fracture resistance of the material. It was also resistant to
shattering and fragmentation by impact load. Research with actual radioactive cesium-chloride
was not pursued due to resource limitations.
Research performed at Ames Laboratory on americium-beryllium substituted non-radioactive
compounds with similar physical properties as a surrogate for americium-beryllium. Hot pressing
and pressureless sintering, using aluminum as an intermediate liquid phase, were used to fabricate
dense, hard, and strong material that resisted shattering or other means of dispersal. This research
also successfully demonstrated the application of surface modification techniques, such as
nitriding and deposition of ceramic coatings, to surface-harden stainless steel material, which is
used for sealed sources capsules.
Both NRC research programs showed promise in identifying the potential for dispersible material
to be made less dispersible or dispersion-resistance. However, funding for both programs was
terminated in 2005 and no additional research is planned. This research was particularly
significant in demonstrating that radioactive materials can made less-dispersible thus reducing
their risks associated both with accidental release and use in an RDD. Key issues that remain to
be answered are the stability, over extended periods, of these matrices in the highly radioactive
and hot environment in the interior of a sealed source. In addition, the effect of the build up of
the decay products on the molecular structure of the matrices needs to be examined.
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U.S. Department of Energy
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In addition, very preliminary results from the University of 1New Mexico State University
indicate cesium chloride powder can be made more dispersion resistant using an inexpensive
technical step in its production. Specifically, the heating of the cesium chloride powder above
its melting point and then cooling it converts the powder to a solid crystalline structure. The
current research involves non-radioactive cesium chloride however additional research needs to
be conducted using radioactive cesium chloride.
Another way to prevent dispersal is to make the source capsule difficult to penetrate. As
indicated above, the NRC funded research at the Ames laboratory included efforts to harden
sealed source capsules by modifying their surfaces. In addition to this effort, there are other
techniques that should be investigated such a new types of materials for source capsules or
thickening the source capsule. An important consideration in these types of investigation is to
make sure that the new types of source capsules do not significantly modify the energy of the
radiation emitted by the sealed source.
Sources That Are Less Hazardous To Human Health
Because of their physical and chemical properties, certain radioactive materials and sources are
less hazardous to human health. For example, a radioisotope that acts as an alpha emitter during
decay could be replaced by a radioisotope that is a beta or gamma emitter. The key factors to
consider in assessing the hazard to a person are:
•
•
•
•
The time is takes for the material to decay.
Energy of the radiation emitted
The type of radiation emitted
The time the material resides in the body
Using these factors, strategies for reducing the harm to humans and impact on infrastructure can
be developed. International and national scientific organizations have published documents that
assess the harm produce by many radioactive isotopes normalized to radioactivity (i.e on a per
Curie basis). Thus, it should be a relatively simple process to identify less hazardous substitutes
for the set of isotopes currently used in industry. However, the set of isotopes currently used by
industry have been in use for a long time and probably represent those radioactive materials that
are economically most advantageous to use based on cost, availability, and other features.
Accordingly, it will be necessary to evaluate the practicality of substituting less hazardous
radioactive materials for currently used radioactive materials.
For example, if the oil exploration industry could work with a 1 MeV monoenergetic neutron
source, a couple of viable gamma emitters are available. The primary improvement would be a
source that decays to insignificance in a decade or two instead of centuries. However, because
gamma emitters are not efficient as alpha emitters, such as americium) a significantly larger
amount the gamma emitter would be needed to produce a useable level of neutrons.
A novel way to apply this approach would be to use portable or miniature neutron generators
(e.g., D-T accelerators), similar to those discussed above as replacements to sealed neutron
sources, to produce radioactive isotopes locally as needed. As discussed in Appendix C,
exposure of certain types of non radioactive materials with neutrons produces radioactive
isotopes. Typically these isotopes have very short half lives, on the order of hours or days and
thus, would not present a significant hazard in an RDD. An example of this approach is the
replacement of cesium-137 (half life 30 years) by cesium-132 (half life 6.5 days). Cesium-132 is
produced by irradiating non-radioactive cesium-133 with neutrons and it emits almost the same
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U.S. Department of Energy
Alternatives to Industrial Radioactive Sources
energy as cesium-137. Thus it could be substituted for cesium-137. However, because of the
concerns listed blow, widespread use of such radioactive materials may be problematic.
The very short half lives of radioactive materials produced by neutron irradiation limit the
applications for which these materials would useful because only this approach only be practical
for applications where a rapidly decreasing radiation field is acceptable. In addition, the dose to
workers may increase because of the radiation source would have to be constantly regenerated
and replaced. Finally,, the neutron generators would have to generate enough neutrons to
produce useful quantities of radioactive isotopes in a relatively short time to be practical. (Note, it
seems unlikely that sufficient isotopes could be generated in this manner to be used in
applications that require sealed sources containing IAEA class 1 or 2 quantities of radioactive
materials.) Accordingly, research is needed to identify isotopes for which could replace current
sealed sources and to develop portable neutron generators with sufficient neutron generating
capacity to produce useful quantities of these isotopes. In addition, potential doses to workers
would have to be analyzed.
4.3 Utilize Integrated Security Features if Alternative is Not Available
Some applications of sealed sources may not lend themselves to a technical or economically
viable replacement. If alternative technologies cannot be identified, additional security and
control should be incorporated to aid in the protection of radioactive sealed sources. Two types
of security devices intended to supplement existing security measures are envisioned. One type
would provide an alert that a sealed source had been tampered with. Another type would be
tracking device integrated into the sealed source. Both of these security devices are intended to
aid individuals who would respond in the event a source was stolen by alerting them to a sealed
source theft and the location of the stolen source.
Devices intend to warn of tampering could be based on continuous monitoring of the radiation
field produced by the sealed source and be designed to alarm if the existing radiation level in the
vicinity of a sealed source changed. Because the scenario a terrorist would use to steal a sealed
source is not known such devices could be programmed to alarm based on a set of predetermined
temporal variations in the radiation level. Clearly such alarms would have to be designed to
permit authorized operations. One key aspect in the design of such devices would be to keep the
number of false alarms at or below some acceptable level.
Devices intend to track the location of sealed source could be a passive or active in design. A
passive device could be similar to the microchip imbedded in high value property or in animals.
The drawbacks to passive devices is that these types of devices only emit a signal in response to
exposure to some type of non-ionizing radiation field. Thus, one would have to know the
approximate location of the source when using a passive device. However, if one knew the
approximate location of the radiation source, the radiation emitted by the source itself could act as
a tracking device.
An active device could continually track the source using global positioning technology. In each
case, the tracking devices would be required to continue to operate in close proximity to
significant radiation fields. The drawback to active devices is that the material needed to shield
the source will also block the electro-magnetic signal it uses to communicate with external
receivers. Accordingly, active tracking device would only be able to provide the location of a
source when it is unshielded. The most likely times would be when it is being removed and when
it is being incorporated into an RDD.
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U.S. Department of Energy
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Based on the above, research should focus on using a combination of “tamper” alarms and active
detectors to optimize the response of individuals or groups in response to a terrorist operjation to
a sealed source. In addition, research is needed to determine whether or not a tracking device
would be able to function in the high radiation, high-temperature environment of a sealed source.
5. Need For Incentives:
Application of alternative technologies may not be effective unless economic incentives are
established to encourage the adoption of those alternatives. U.S. market place competition
typically encourages, evaluates, and ultimately determines if non-radioactive technology will take
the place of radioactive sources or devices. Also, it is recognized that there are some alternative
technologies that have been in the marketplace but have not been sufficiently attractive to replace
radioactive sources and devices yet. Thus, even if alternatives are viable, adoption of the
alternative in the commercial sector will depend on its feasibility as well as its economic
attractiveness. Accordingly, a wide range of incentives may be needed and should be established
with stakeholder input. Regulatory mandates or economic incentives such as underwriting the
disposal cost or providing tax incentives may be required to encourage use of the alternatives. It
may be useful to work with EPA, NRC, and various sealed source manufacturing and user
communities to identify the most effective set of incentives for encouraging the use of alternative
technologies to reduce the risks associated with sealed sources.
6. Disposition of Sources Displaced by Alternatives
The creation of alternatives to Category 1 and 2 radioactive sealed sources will most likely result
in the generation of disused sources becoming radioactive waste. As the radioactive sources are
replaced with alternatives, they will become waste and will require a disposal path. As noted
previously, some of these newly created waste materials do not have a regulatory approved
disposal pathway; other sources may be owned by companies that cannot afford to replace their
existing source with the alternative technology or to dispose of their sealed source. Thus
incentives should be provided by the Federal government to aid both in the adoption of the new
technology and to assist in offsetting the disposition cost of any disused source.
7. Research and Development Recommendations
If resources are identified, the Department recommends that requests for proposal be developed to
address the following projects:
•
Use of accelerators that produce X-rays that provide energies and intensities similar to
isotopes currently used by industry.
•
Development of neutron generators that are sufficiently rugged to withstand industrial
environments, such as well logging.
•
Development of miniature portable neutron generators that could generate high fluxes of
neutrons.
•
Develop improved encapsulation materials that are resistant to fire, explosions, or
penetration by cutting or drilling tools.
•
Identify isotopes for various industrial operations that could be replaced by less-hazardous
isotopes without any loss of function.
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U.S. Department of Energy
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•
Determine the stability, over time, of the crystalline structure of radioactive isotopes used in
sealed sources.
•
Examine the effectiveness of integrating tracking devices into the high radiation, hightemperature environment of a sealed source.
•
Examine whether the combined response of “tamper” alarms and tracking devices would
thwart theft of a sealed source.
This program should be run by the Department of Energy’s Office of Science and should include,
but not be limited to, contractors and facilities currently administered by the Office of Science.
5.2 Collaborative Efforts
•
The DOE should partner with the EPA in identifying non-radioactive alternatives to sealed
sources and radiation generating devices
•
The DOE should coordinate with the NRC’s research and development program to identify
Category 1 and 2 sources that can be modified or created to be RDD-resistant and support
NRC efforts to investigate the effects of the environment inside a sealed source on the
structural integrity of materials proposed for dispersion resistant sealed sources.
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U.S. Department of Energy
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Appendix A
Acronyms and Abbreviations
AEA
Atomic Energy Act of 1954, as amended
CFR
Ci
Code of Federal Regulations
Curies
DoD
DOE
DOS
DOT
U.S. Department of Defense
U.S. Department of Energy
U.S. Department of State
U.S. Department of Transportation
EIS
EPA
Environmental impact statement
U.S. Environmental Protection Agency
GTCC
Greater-than Class C
IAEA
International Atomic Energy Agency
LANL
LLRW
LLRWPAA
Los Alamos National Laboratory
low-level radioactive waste
Low-Level Radioactive Waste Policy Amendment Act of 1985
MOU
Memorandum of Understanding
NASA
NNSA
NRC
NSTS
National Aeronautics and Space Administration
National Nuclear Security Administration
U.S. Nuclear Regulatory Commission
National Source Tracking System
OSR
Off-site Source Recovery
RAMQ
RDD
RTG
RTR
Radioactive Material Quantity of Concern
Radiological dispersal device
Radioisotope Thermoelectric Generators
Radiological Threat Reduction
U.S.
United States
WESF
WIPP
Waste Encapsulation and Storage Facility
Waste Isolation Pilot Plant
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U.S. Department of Energy
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Appendix B
International Atomic Energy Agency
Code of Conduct List of Sources (Annex 1 of the Code):
The Code of Conduct categorization is composed of a list of 26 radionuclides and threshold
activity levels that fall into categories that define a dangerous source (a source that could, if not
under control, give rise to exposure sufficient to cause severe deterministic effects (i.e., an effect
that is fatal or life threatening or results in a permanent injury that reduces the quality of life)).
The underlying methodology for the categorization is detailed in IAEA Safety Guide No. RS-G1.9. In general:
•
Category 1: personally extremely dangerous. If not safely managed or securely
protected would be likely to cause permanent injury to a person who handled them,
or were otherwise in contact with them, for more than a few minutes. It would
probably fatal to be close to this amount of unshielded material for a period of a few
minutes to an hour. These sources are typically used in practices such as radiothermal
generators, irradiators and radiation teletherapy.
•
Category 2: personally very dangerous. If not safely managed or securely protected,
could cause permanent injury to a person who handled them, or were otherwise in
contact with them, for a short time (minutes to hours). It could possibly be fatal to be
close to this amount of unshielded radioactive material for a period of hours to days.
These sources are typically used in practices such as industrial gamma radiography,
high dose rate brachytherapy and medium dose rate brachytherapy.
•
Category 3: personally dangerous. If not safely managed or securely protected, could
cause permanent injury to a person who handled them, or were otherwise in contact
with them, for some hours. It could possibly – although unlikely – be fatal to be close
to this amount of unshielded radioactive material for a period of days to weeks. These
sources are typically used in practices such as fixed industrial gauges involving high
activity sources (for example, level gauges, and some logging gauges.
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U.S. Department of Energy
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Table B-1: IAEA Radionuclides of Concern
Category 1
Radionuclide
Category 2
1000 x D
Category 3
10 x D
D
(TBq)
(Ci)a
2.E+01
6.E-02
2.E+00
6.E-01
2.E+01
6.E-02
2.E+00
5.E+02
2.E-01
5.E-00
2.E-02
5.E-01
(TBq)
(Ci)
Am-241
6.E+01
Am-241/Be
a
(TBq)
(Ci)
2.E+03
6.E-01
6.E+01
2.E+03
Cf-252
2.E+01
a
Cm-244
5.E+01
1.E+03
5.E-01
1.E+01
5.E-02
1.E+00
Co-60
3.E+01
8.E+02
3.E-01
8.E+00
3.E-02
8.E-01
Cs-137
1.E+02
3.E+03
1.E+00
3.E+01
1.E-01
3.E+00
Gd-153
1.E+03
3.E+04
1.E+01
3.E+02
1.E+00
3.E+01
Ir-192
8.E+01
2.E+03
8.E-01
2.E+01
8.E-02
2.E+00
Pm-147
4.E+04
1.E+06
4.E+02
1.E+04
4.E+01
1.E+03
Pu-238
6.E+01
2.E+03
6.E-01
2.E+01
6.E-02
2.E+00
Pu-239 /Be
6.E+01
2.E+03
6.E-01
2.E+01
6.E-02
2.E+00
Ra-226
4.E+01
1.E+03
4.E-01
1.E+01
4.E-02
1.E+00
Se-75
2.E+02
5.E+03
2.E+00
5.E+01
2.E-01
5.E+00
Sr-90 (Y-90)
1.E+03
3.E+04
1.E+01
3.E+02
1.E+00
3.E+01
Tm-170
2.E+04
5.E+05
2.E+02
5.E+03
2.E+01
5.E+02
Yb-169
3.E+02
8.E+03
3.E+00
8.E+01
3.E-01
8.E+00
Au-198*
2.E+02
5.E+03
2.E+00
5.E+01
2.E-01
5.E+00
Cd-109*
2.E+04
5.E+05
2.E+02
5.E+03
2.E+01
5.E+02
Co-57*
7.E+02
2.E+04
7.E+00
2.E+02
7.E-01
2.E+01
Fe-55*
8.E+05
2.E+07
8.E+03
2.E+05
8.E+02
2.E+04
Ge-68*
7.E+02
2.E+04
7.E+00
2.E+02
7.E-01
2.E+01
Ni-63*
6.E+04
2.E+06
6.E+02
2.E+04
6.E+01
2.E+03
Pd-103*
9.E+04
2.E+06
9.E+02
2.E+04
9.E+01
2.E+03
Po-210*
6.E+01
2.E+03
6.E-01
2.E+01
6.E-02
2.E+00
Ru-106
(Rh-106)*
3.E+02
8.E+03
3.E+00
8.E+01
3.E-01
8.E+00
Tl-204*
2.E+04
5.E+05
2.E+02
5.E+03
2.E+01
5.E+02
b
a
The primary values to be used are given in TBq. Curie values are provided for practical usefulness and
are rounded after conversion.
b
Criticality and safeguard issues will need to be considered for multiples of D.
*These radionuclides are very unlikely to be used in individual radioactive sources with activity levels that
would place them within Categories 1, 2, or 3 and would, therefore, not be subject to the paragraph
relating to national registries or the paragraphs relating to import and export control (See IAEA Safety
Guide No. RS-G-1.9.)
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Appendix C
Applications for Medical Radioisotopes
Approximately 100 radioisotopes are used in medical diagnosis, sterilization of medical products,
radiotherapy, and research in nuclear medicine. Only a few have quantities of concern for
possible diversion. In radiotherapy, teletherapy sources contain 1,350 to 27,000 Curies of cesium137 or cobalt-60.
Blood irradiators use cesium-137 or cobalt-60 to sterilize blood and kill antigens before a
transfusion. Blood irradiators have been in production since the 1950s to help protect the world’s
blood supply. Some manufacturers will take the units back for remanufacture, but disposal
options are minimal. An alternative technology for the cesium based blood irradiator would be
the x-ray based blood irradiator.
Teletherapy devices use cobalt-60 and cesium-137 sealed sources for treating cancer by placing a
radioactive source in the device, then focusing the resulting radiation beam on the cancerous
portion of the patient’s body. Teletherapy devices in the United States have been replaced with
particle accelerators. The excess teletherapy devices were shipped to foreign countries.
It is unlikely that these countries would replace these devices with electron accelerators because
of the lack of reliable electrical power and skilled technicians to operate them.
A variation of the teletherapy device is the gamma knife, which is used for the treatment of brain
cancer. Gamma knife stereotactic radiosurgery has revolutionized the treatment of small brain
tumors that were considered inoperable by furnishing the precision needed to focus intense
radiation on tumor tissue deep within the brain, while minimally affecting the surrounding
noncancerous areas. Hundreds to thousands of Curies of cobalt-60 are involved.
Brachytherapy uses iridium-192 metallic seeds in High Dose Rate (HDR) afterloading systems to
treat cancer by direct implantation of the source radiation within the tumor. The HDR unit is selfshielded and highly mobile. Cesium-137 “needles” and iridium-192 “seed ribbons” are also
employed in brachytherapy. These sources are low activity, on the order of millicuries, and would
create a nuisance if employed in an RDD, but would be unlikely to create a significant exposure
problems. Brachytherapy is in wide use for gynecological and prostatic cancers. Alternative
technologies include surgery, external beam therapy, chemotherapy, and, for prostate cancer,
permanent iodine-125 seed implantation.
In the search for alternative technologies to radionuclear medicine, it’s important to consider not
only the economic impact—healthcare costs could escalate if the alternative technology is more
expensive—but more importantly, the quality of patient care and the life-saving applications of
the radionuclide. In addition, the costs of disposal of the disused source would need to be
considered to prevent it from being donated or sold.
Table C-1: Applications and Numbers of Medical Devices
Using NRC-regulated Radioactive Sources*
Application
Radionuclides
Activity Range
Medical
Cobalt-60
10 Ci – 13,000 Ci
Cesium-137
27 Ci – 12,000 Ci
Iridium-192
24 Ci
*NRC 2005 Interim Inventory Data - IAEA Category 1 and 2 sources regulated by NRC
29
No. of
Units
176
417
1
Alt. Tech. Exist
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Appendix D
Production Methods for IAEA Code of Conduct Radioisotopes
The IAEA Code of Conduct lists 25 different radioisotopes (see Appendix B) used in the
manufacture of radioactive sources. Depending on the strength of the source, IAEA classifies
these sources as health hazard Categories 1, 2, and 3, with Category 1 being the most lethal.
These radioisotopes are produced in a number of ways and used by industry for different
purposes.
The NRC organizes radioactive waste into three classes:
•
•
•
Low Level Radioactive Waste (LLRW)
High Level Radioactive Waste (HLRW)
Transuranic Waste (TRUW).
These classifications define the disposal route. Most IAEA Category 1, 2, and 3 sealed sources
are classified by NRC as LLRW and are disposed of by established methods for LLRW.
IAEA Code of Conduct categories and NRC waste classifications are defined by a number of
factors, such as the origin and strength of the radioactive materials and whether they long-lived or
not. This appendix examines how these radioisotopes are produced.
Radioisotope production
Most radioisotopes do not occur naturally. They must be made via a number of nuclear reaction
pathways, usually followed by chemical purification or mass separation in order to have a high
concentration of the desired radionuclide. There are many different types of nuclear reactions, but
the ones employed to manufacture the isotopes listed in IAEA Code of Conduct require either a
reactor, an accelerator, or are by-products extracted from spent reactor fuel or by natural
radioactive decay.
Reactor-made radioisotopes:
A reactor provides a flux of neutrons that can be used for isotope production. The neutrons are
captured by the atoms in the target material that has been inserted into the reactor core. Often the
radioisotope is made from the same element as the target material but one neutron heavier. An
example of this is nickel-63. By inserting a non-radioactive nickel-62 target into the reactor core
and irradiating it with a high flux of neutrons for a sufficient length of time, some of the nickel-62
atoms are converted into radioactive nickel-63. Other radioisotopes require the capture of more
than one neutron, for example curium-244. A plutonium-242 target is used to captures two
neutrons to make plutonium-244. This isotope then undergoes decay to make curium-244. The
curium must then be extracted chemically from the target material before it is manufactured into a
source.
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Table D-1: Reactor-made IAEA Code of Conduct radioisotopes.
Radioisotope
Target
Reaction (Assume single
neutron capture unless
otherwise noted.)
Common Forms
Ac-227
Ra-226
Single neutron capture followed by
beta decays
HCl solution
Au-198
Au-197
Single neutron capture
Metal
Cd-109
Enriched Cd-108
Single neutron capture
Metal
Cf-252
Transuranics
multiple neutron capture followed
by beta decay
Solution or custom
forms
Cm-244
Pu-242
double neutron capture followed by
beta decay
Oxide
Co-60
Co-59
Single neutron capture
Nickel-plated
pellets
Gd-153
Enriched Gd-152
Single neutron capture
Metal
Fe-55
Enriched Fe-55
Single neutron capture
Metal
I-125
Xe-124
Xe-125 beta decays to I-125
NaI, KI
Ir-192
Enriched Ir-191
Single neutron capture
Metal
Ni-63
Enriched Ni-62
Single neutron capture
HCl solution
Pd-103
Enriched Pd-102
Single neutron capture
Metal
Pm-147
Enriched Nd-146
Nd-147 beta decays to Pm-147
HCl solution
Po-210
Bi-209
Bi-210 beta decays to Po-210
HCl solution
Pu-238
U-236
U-237 beta decays to Np-237,
which captures neutron, then beta
decays to Pu-238
Oxide
Se-75
Enriched Se-74
Single neutron capture
Metal
Tl-204
Enriched Tl-203
Single neutron capture
Metal
Tm-170
Tm-169
Single neutron capture
Metal
Yb-169
Enriched Yb-168
Single neutron capture
Metal
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Accelerator-made Radioisotopes:
An accelerator, such as a linear accelerator (commonly called a linac) or a cyclotron, provides a
beam of protons for radioisotope production. These protons strike the atoms in the target material
that is placed in the pathway of the beam. When this happens, a number of different types of
nuclear reactions may occur: the incoming proton may knock out one or more neutrons, some
protons, or combinations of neutrons and protons.
The production of Fe-55 is one example. Mn-55 is used as the target material. The incoming
proton is captured and knocks out a neutron, thus making the Fe-55. (This is called a “p-n”
reaction.) The target material and proton beam energy must be optimized to maximize the yield of
the desired radioisotope. The irradiated target, once removed from the beam line, needs to be
processed in order to extract the radioisotope of interest.
Table D-2: Accelerator-made IAEA Code of Conduct Radioisotopes.
Radioisotope Target
Reaction
Common
Form
Cd-109
Co-57
Natural Indium
Ni-58
Proton spallation*
(p,2n)
HCL solution
HCl solution
Fe-55
Mn-55
(p,n)**
HCl solution
Ge-68
Gallium chloride
Rubidium bromide
Molybdenum metal
Natural Gallium
Gallium-69
Various p-n reactions
Various p-n reactions
Proton spallation
(p,xn)
(p,2n)
HCl solution
Se-75
Rubidium bromide
Proton spallation
HCl solution
*Proton spallation is a nuclear reaction is which the incoming proton knocks out several protons
and neutrons from the target nucleus.
**Referred to as a “p-n reaction.” This simply means one proton from the beam has displaced a
neutron, which has been ejected by the nucleus. Similarly for a p,2n reaction, where 2 neutrons
have been ejected. The letter x signifies that more than one neutron can be ejected. Its value
depends on the specific nuclear reaction
By-products radioisotopes:
Fission by-products are usually chemically extracted from spent nuclear fuel. Examples are Sr-90,
Cs-137, and Kr-85. By-products are also produced from the natural decay of another isotope. An
example of this is the decay of Cm-244 (see Table D-1) to Pu-240 by alpha decay. As the Cm244 decays, the amount of Pu-240 increases. After enough plutonium has grown in, it is
chemically extracted from the curium.
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Table D-3: By-product IAEA Code of Conduct Radioisotopes.
Radioisotope
Source
Common Form
Am-241
Cs-137
Extracted from Pu-241, which beta
decays to Am-241
Fission product extracted from uranium
and plutonium spent fuel
Kr-85
Fission product extracted from spent
reactor fuel
Pm-147
Fission product extracted from uranium
and plutonium spent fuel
Pu-236
Extracted from spent uranium and
plutonium fuel
Extracted from spent uranium and
plutonium fuel
Cm-244 alpha decays to Pu-240
Pu-239
Pu-240
Ra-226
Extracted from U-234, which alpha
decays to Ra-226
Ru-106
Fission product extracted from uranium
and plutonium spent fuel
Sr-90
Fission product extracted from uranium
and plutonium spent fuel
Th-229
Extracted from U-233, which alpha
decays to Th-229
Oxide
Oxides
Oxides
Oxides
HNO3 solution
The production of the various plutonium isotopes can be viewed as either reactor made or byproducts. Their production often starts with various isotopes of uranium either as reactor target
material or reactor fuel. These isotopes of uranium are bombarded with neutrons to produce other,
heavier isotopes of uranium that decay to various isotopes of neptunium. These neptunium
isotopes undergo additional beta decay to produce a range of plutonium isotopes. These
plutonium isotopes are then sorted out using a mass separator. Enriched isotopes of uranium are
also used as reactor target materials to make specific plutonium radioisotopes. An example of this
is Pu-238, which uses U-236 as the initial target material. It’s listed under reactor-made
radioisotopes.
Neutron sources:
The following are listed as IAEA Code of Conduct sources:
•
•
Am-241/Be
Pu-239/Be
These are neutron sources. The radioactive species are Am-241 and Pu-239, both of which decay
with the emission of an alpha particle. Their methods of production are listed in the tables above.
Beryllium (Be), on the other hand, is a stable light-weight metal. Beryllium is combined with
these two radioisotopes in order to make a neutron source. The alpha particles emitted by the Am241 and Pu-239 are energetic enough to break up the beryllium nucleus with the emission of a
neutron.
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Appendix E
United States Regulatory Guidance for Sealed Source Management
Department of Energy
The DOE (DOE) has established controls for ionizing radiation in Title 10 United States Code of
Federal Regulation Part 835 “Occupational Radiation Protection.” The DOE places additional
requirements on these materials through a system of contractually mandated DOE Orders. The
DOE’s 10 CFR 835 regulations mandate requirements for sealed source accountability and
control at isotope amounts which are significantly lower than the IAEA Category 1 and 2 source
thresholds. DOE sources are used and stored at DOE controlled facilities, the Department acts as
the owner of these materials and allows operations with these materials through regulatory and
contract mechanisms. This requirement is in contrast to the NRC’s responsibility to regulate the
use of byproduct materials throughout the United States (excluding DOE facilities and activities).
Nuclear Regulatory Commission
The NRC controls category 1 and 2 sealed sources through Title 10 United States CFR Part 20
“Standards for Protection against Radiation.” This regulation specifies the necessary controls for
sealed sources that are derived from by product material. The NRC defines byproduct material as
“any radioactive materials (except special nuclear material) yielded in. or made radioactive by,
exposure to the radiation incident to the process of producing or utilizing special nuclear
material.’ This requirement, currently, limits the scope of the NRC regulations to large industrial
sources that are made from the nuclear reactor process. The NRC requires potential users of
radioactive materials to apply for an NRC Nuclear Material License. The NRC license sets the
possession limits for the licensee, the general conditions in which the materials can be used,
identifies inventory requirements and disposal requirements when the material or source is no
longer needed. The NRC has been granted the authority to transfer its regulatory authority to
‘Agreement States’ provided the States can show they have the regulatory program and resources
that are comparable to the NRC. As with the DOE 10 CFR 835 regulation, the NRC and
Agreement States regulate more isotopes at much lower quantities than the IAEA code of
conduct.
Other Federal Agencies
The Department of Transportation, Department of Defense, Department of Homeland Security,
Department of State, Occupational Health and Safety Administration and Environmental
Protection Agency generate regulations for specific applications with radioactive materials.
The Department of Transportation (DOT) has the primary responsibility to regulate the
transportation of Class 7 radioactive materials in motor vehicles, rail cars, or freight containers.
The DOT regulations, in general, provide specification on the type and construction of the
containers used to transport sealed sources. The DOE and NRC share some oversight
responsibility of radioactive material transportation with the DOT.
The Department of Defense regulates military applications of radioactive material, the ,
Department of State extends control with the DOE and NRC to regulate import and export of
radioactive materials to foreign countries, and the Environmental Protection Agency regulates
and recovers material in cooperation with the DOE orphan source recovery program.
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Appendix F
Glossary
1. Disused Source. A radioactive source which is no longer used, and is not intended to be used,
for the practice for which an authorization has been granted.
2. Industrial Applications. The IAEA identifies industrial applications for radioactive sources as
being industry, medicine, research, agriculture, and education. An NRC proposed rule states
that radioactive sources are being used in the following industries: oil and gas, electrical
power, construction, medical, and food. The GAO acknowledges radioactive sources as also
being used in commercial manufacturing and research activities (government and private).
3. Large Radioactive Source. The IAEA Code of Conduct includes a system for categorizing
radioactive sources based on their potential to cause harm to people. The system places
sources into five categories, with 1 being the greatest risk and 5 the lowest risk. Categories 1,
2, and 3 are all classified as “dangerous” sources. For this report, the radioactive sources
listed in Categories 1, 2, and 3 are considered to be large radioactive sources. They
encompass sources that LANL determined to be “large radiological sources of concern”
based on their radioactivity level and concerns related to transport, contamination, and dose
emitters. They include all industrial and research irradiators, all teletherapy units and blood
irradiators, all of the RTGs, seed irradiators, high-end well-logging sources (exceed 10 Curies
of plutonium or americium), and the very largest radiography sources.
a. Category 1. Personally extremely dangerous. This amount of radioactive material, if
not safely managed or securely protected would be likely to cause permanent injury
to a person who handled them, or were otherwise in contact with them, for more than
a few minutes. It would probably be fatal to be close to this amount of unshielded
material for a period of a few minutes to an hour.
b. Category 2. Personally very dangerous. This amount of radioactive material, if not
safely managed or securely protected, could cause permanent injury to a person who
handled them, or were otherwise in contact with them for a short time (minutes or
hours). It could possibly be fatal to be close to this amount of unshielded radioactive
material for a period of hours to days.
c. Category 3. Personally dangerous. This amount of radioactive material, if not safely
managed or securely protected, could cause permanent injury to a person who
handled them, or were otherwise in contact with them for some hours. It could
possibly, although it is unlikely, be fatal to be close to this amount of unshielded
radioactive material for a period of days to weeks.
4. Orphan Source. A radioactive source which is not under regulatory control, either because it
has never been under regulatory control or because it has been abandoned, lost, misplaced,
stolen, or transferred without proper authorization.
5. Safety. Measures intended to minimize the likelihood of accidents involving
radioactive sources and, should an accident occur, to mitigate its consequences.
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6. Sealed Source. A sealed radioactive source having a half-life equal to or greater than
30 days and an isotopic activity level equal to or greater than the corresponding value
given in Appendix E of 10 CFR Part 835.
7. Security. Measures to prevent unauthorized access or damage to, and loss, theft or
unauthorized transfer of, radioactive sources.
8. Storage. To hold radioactive sources in a facility that furnishes containment with the
intention of retrieval.
9. Well logging Radioactive Sources. Well logging is a method of studying the materials
surrounding exploratory boreholes. A tool consisting of a neutron or gamma-ray
source and one or more detectors is lowered into the borehole. The response of the
detectors to radiation returning from outside the borehole depends in part on the
lithology, porosity, and fluid characteristics of the material. In principle, the
characteristics of the materials outside the borehole can be inferred from the response
of the detectors.
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Appendix G
References
Nuclear Regulatory Commission, Report on Radiation Protection and Security Task Force,
Report to the President and Congress, Draft Report, April 24, 2006
Lawrence Livermore National Laboratory (LLNL). Home page, description of research projects.
www.llnl.gov (accessed April 2006).
Off-Site Source Recovery Project, www.doeal.gov/OSRP/, description of activities; (accessed
April 2006)
Nuclear Regulatory Commission; www.nrc.gov, description of licensing process and types,
accessed April 2006).
International Atomic Energy Agency, Development opportunities for small and medium scale
accelerator driven neutron sources Report of a technical meeting held in Vienna, 18–21 May
2004, IAEA TECDOC 1439, February 2005
International Atomic Energy Agency, Strengthening control over radioactive sources in
authorized use and regaining control over orphan sources National strategies, IAEA-TECDOC1388, February 2004
International Atomic Energy Agency, Code of Conduct on the Safety and Security of Radioactive
Sources, January 2004
Van Tuyle, George, et al, “Life-Cycles of Large Radiological Sources – Assessing RDD
Concerns and Options,” November 2003.
Van Tuyle, G. et al., Reducing RDD Concerns Related to Large Radiological Source
Applications, Los Alamos National Laboratory, LA-UR-03-6664, September 2003
Report to the Nuclear Regulatory Commission and the Secretary of Energy, Radiological
Dispersal Devices, An Initial Study to Identify Radioactive Materials of Greatest Concern and
Approaches to Their Tracking, Tagging, and Disposition, May 2003.
Government Accounting Office, NUCLEAR NONPROLIFERATION DOE, Action Needed to
Ensure Continued Recovery of Unwanted Sealed Radioactive Sources, GAO 03-438, April 2003.
Government Accounting Office, Nuclear Security: Federal and State Action Needed to Improve
Security of Sealed Radioactive Sources, GAO-03-804, August 2003.
Ferguson, C. D., Perera J., Taseen, K., Commercial Radioactive Sources, Surveying the Security
Risks, Monterey Institute of International Studies, Occasional Paper Number 11, January 2003
Morrison, R. M., An Economic Analysis of Electronic Accelerators and Cobalt-60 for Irradiating
Food, (U.S. Department of Agriculture Technical Bulletin, 1762), June 1989
37