Characterization Surveys and
Early Site Investigations
Tom Hansen, CHP, PMP
Ameriphysics, LLC
[email protected]
Outline
• Introduction to Characterization
• Overview of the RSSI Process
• Historical Site Assessment
• Radiological Surveys
• Other Considerations
• Summary
• References
copyright 2010
-2-
Ameriphysics, LLC
Introduction to Characterization
• Characterization can be viewed as the initial steps
toward site decommissioning
• It is an iterative process, and is used to:
– Define the scope of work and prepare site plans
– Select decontamination and decommissioning techniques
– Develop waste disposal strategies
– Refine cost estimates and schedules
– Collect data needed for regulatory or stakeholder approval
– Develop ES&H controls
– Determine release criteria, and
– Provide input for Final Status Survey design
copyright 2010
-3-
Ameriphysics, LLC
Introduction to Characterization
Inputs
• The primary types of activities performed during
characterization consist of records and documentation
reviews, surveys and sampling, and data analysis and
dose modeling
• The following graph shows an example of the level of
each of these activities during a decommissioning
project – not actual data, rather graph to show focus of
effort over project
copyright 2010
-4-
Ameriphysics, LLC
Introduction to Characterization
100
50
Analysis
Surveys
Records
0
Records
95
70
30
10
0
0
0
10
Surveys
5
25
40
60
50
30
20
20
Analysis
0
5
30
30
50
70
80
70
copyright 2010
-5-
Records
Surveys
Analysis
Ameriphysics, LLC
Introduction to Characterization
Outputs
• The type and extent of radiological and non-rad
contaminants
• The level of surface and volumetric contamination
• Site-specific pathways and any off-site contaminants
• Background reference areas (if needed)
• Recommendations regarding instrumentation, analytical
methods, and data analysis protocols
• The data necessary to conduct further project planning
• Input for final status/release surveys
copyright 2010
-6-
Ameriphysics, LLC
Introduction to Characterization
Regulator and Stakeholder Interaction
• Since characterization provides information to support
license termination – both regulators and
stakeholders are often keenly interested in the
planning and conduct of characterization
• These interests often manifest themselves as
regulatory and stakeholder approvals of the
characterization plan
• The characterization planning process should be
developed in a manner to support outside reviews
copyright 2010
-7-
Ameriphysics, LLC
Overview of the RSSI Process
Radiation Survey and Site Investigation (RSSI)
Process
• A consensus approach, agreed upon by DOE, DOD,
EPA, and NRC, to demonstrate compliance with a dose
or risk-based regulation
• A graded approach that starts with the Historical Site
Assessment (HSA) and is later followed by other
surveys that lead to the final status survey
• Each survey has specified goals and objectives to
support a final decision on whether or not a site or
facility complies with the appropriate regulations
copyright 2010
-8-
Ameriphysics, LLC
Overview of the RSSI Process
Steps of the RSSI Process
• Site Identification
• Historical Site Assessment
• Scoping Survey
• Characterization Survey
• Remedial Action Support Survey
• Final Status Survey
• Confirmation and Verification
copyright 2010
-9-
Ameriphysics, LLC
Historical Site Assessment
The primary purpose of the Historical Site
Assessment (HSA) is to collect existing information
concerning the site and its surroundings
• Areas that have no reasonable potential for residual
contamination are classified as non-impacted areas
• Areas with some potential for residual contamination are
classified as impacted areas
copyright 2010
- 10 -
Ameriphysics, LLC
Historical Site Assessment
The primary objectives of the HSA are to:
• Identify potential sources of contamination
• Determine whether or not the site poses a threat to
human health and the environment
• Differentiate impacted from non-impacted areas
• Provide input to scoping and characterization survey
design
• Provide an assessment of the likelihood of contaminant
migration, and
• Identify additional potential radiation sites
copyright 2010
- 11 -
Ameriphysics, LLC
Historical Site Assessment
The HSA typically consists of three phases:
• Identification of a candidate site
• Preliminary investigation of the facility or site
• Site visits or inspections
copyright 2010
- 12 -
Ameriphysics, LLC
Historical Site Assessment
Data Sources
• Design and as built drawings
• Facility modifications
• Licenses, applications, and correspondence
• Routine surveys
• Other operating records and documents
• Interviews with operators and support personnel
• Event log - accidents and unplanned events
• Photographs
• Construction materials
copyright 2010
- 13 -
Ameriphysics, LLC
Historical Site Assessment
The HSA is followed by an evaluation of the
site based on the information collected
• Identify potential contaminants
• Identify potentially contaminated areas
• Identify potentially contaminated media
• Develop a conceptual model of the site
• Professional judgment
copyright 2010
- 14 -
Ameriphysics, LLC
Historical Site Assessment
Identify Potential Contaminants
• How long was the site operational?
• What types of processes occurred at the site?
• What is the probability of leakage from the sources?
• Where are the most likely locations for contamination
within the facility?
copyright 2010
- 15 -
Ameriphysics, LLC
Historical Site Assessment
Identify Potentially Contaminated Areas
• Initial assessment should allow areas to be classified as
impacted or non-impacted
– Impacted areas have a reasonable potential for contamination
based on historical data or known contamination
• Material storage and usage locations; spill, leak, and
discharge areas; onsite disposal or burial locations
– Non-impacted areas have no reasonable potential for residual
contamination
• May be based on site history, previous investigations, or
activity within that portion of the site (i.e. offices vs.
processing area)
copyright 2010
- 16 -
Ameriphysics, LLC
Historical Site Assessment
Identify Potentially Contaminated Areas
• All sources of contamination in impacted areas should be
identified and their dimensions recorded (vertically and
horizontally if possible)
• Sources can be delineated and characterized through:
– Visual inspection (during reconnaissance visit)
– Interviews with knowledgeable personnel associated with the site
– Waste disposal, waste manifests, and waste sampling data
• Potential for migration of contamination (off-site and onsite) should be evaluated where appropriate
copyright 2010
- 17 -
Ameriphysics, LLC
Historical Site Assessment
Identify Potentially Contaminated Media
• Once the potential sources and locations of contamination
have been identified, one must look at the type of
environmental media that has been impacted
• These media include:
– Surface and subsurface soils
– Surface water and ground water
– Air
– Buildings / physical structures
copyright 2010
- 18 -
Ameriphysics, LLC
Historical Site Assessment
Develop a Conceptual Model
• A site diagram showing :
– General layout of the site
• Building locations
• Site boundaries
– Areas of known contamination
– Areas of suspected contamination
– Types and concentrations of contaminants in impacted areas
– Potentially contaminated media, and
– Locations of background (non-impacted) areas
copyright 2010
- 19 -
Ameriphysics, LLC
Historical Site Assessment
Develop a Conceptual Model
• The conceptual model is used to :
– Assess nature and extent of contamination
– Identify potential contaminant sources
– Identify release mechanisms
– Identify potential exposure pathways
– Identify human or ecological receptors
– Identify data gaps, and
– Provide organized approach to assessing the need for and
collecting additional site characterization data
copyright 2010
- 20 -
Ameriphysics, LLC
Historical Site Assessment
Develop a Conceptual Model
• The HSA is the initial step in the development of this
model
• The conceptual model should be upgraded and modified
as the site characterization data become available
copyright 2010
- 21 -
Ameriphysics, LLC
Historical Site Assessment
Professional Judgment
• Professional judgment is the expression of opinion based
on technical knowledge and professional experience,
assumptions, algorithms, and definitions
• There may be circumstances where traditional sources of
information, data, models, or scientific principles are
unavailable, unreliable, conflicting, or too costly or time
consuming to obtain
• Professional judgment can be used as an independent
review of historical data to support decision making in
situations where data are not reasonably obtainable by
collection or experimentation
copyright 2010
- 22 -
Ameriphysics, LLC
Historical Site Assessment
Historical Site Assessment Report
• A document that summarizes what is known about the
site, what is assumed or inferred, activities conducted
during the HSA, and all researched information
• References should be cited for each factual statement
• The report should be organized in such a way that it
supports the site conceptual model
• It may be advisable to have an independent review of the
report for factual accuracy
copyright 2010
- 23 -
Ameriphysics, LLC
Radiological Surveys
Types
• Scoping
• Characterization
• Remedial Action Support
copyright 2010
- 24 -
Ameriphysics, LLC
Radiological Surveys
Scoping Survey
• The primary objectives of a scoping survey are to:
– Perform a preliminary hazard assessment
– Support classification of all or part of the site as a Class 3
area
– Evaluate whether the survey plan can be optimized for use
in the characterization or final status surveys
– Provide input to the characterization survey design if
necessary
copyright 2010
- 25 -
Ameriphysics, LLC
Radiological Surveys
Scoping Survey
• Scoping surveys are conducted after the HSA is
completed and consist of judgment measurements based
on the HSA data
• If the results of the HSA indicate that an area is impacted
and no contamination is found, the area may be
classified as Class 3 and a Class 3 final status survey is
performed
• If the scoping survey locates contamination, the area may
be considered Class 1 or 2 for the final status survey and
a characterization survey is typically performed
copyright 2010
- 26 -
Ameriphysics, LLC
Radiological Surveys
Characterization Survey
• If an area could be classified as Class 1 or Class 2 for
the final status survey, based on the HSA and scoping
survey results, a characterization survey is warranted
• The characterization survey is planned based on the
HSA and scoping survey results
• This type of survey is a detailed radiological investigation
of the area
copyright 2010
- 27 -
Ameriphysics, LLC
Radiological Surveys
Characterization Survey
• The primary objectives of a characterization survey are
to:
– Determine the nature and extent of the contamination
– Collect data to support evaluation of remedial alternatives and
technologies
– Evaluate whether the survey plan can be optimized for use in
the final status survey
– Support Remedial Investigation/Feasibility Study requirements
– Provide input to the final status survey design
copyright 2010
- 28 -
Ameriphysics, LLC
Radiological Surveys
Characterization Survey
• The characterization survey is the most comprehensive
of all the survey types and generates the most data
• This includes preparing a reference grid, systematic as
well as judgment measurements, and surveys of
different media (e.g., surface soils, interior and exterior
surfaces of buildings)
• The decision as to which media will be surveyed is a
site-specific decision addressed throughout the
Radiation Survey and Site Investigation Process
copyright 2010
- 29 -
Ameriphysics, LLC
Radiological Surveys
Remedial Action Support Survey
• If an area is adequately characterized and is
contaminated above the release criterion, a
decontamination plan should be prepared
• A remedial action support survey is performed while
remediation is being conducted and guides the cleanup
in a real-time mode
copyright 2010
- 30 -
Ameriphysics, LLC
Radiological Surveys
Remedial Action Support Survey
• Remedial action support surveys are conducted to:
– Support remediation activities
– Determine when a site or survey unit is ready for the final
status survey
– Provide updated estimates of site-specific parameters used
for planning the final status survey
copyright 2010
- 31 -
Ameriphysics, LLC
Radiological Surveys
Remedial Action Support Survey
• The determination that a survey unit is ready for a final
status survey following remediation is an important step
in the RSSI Process
• Remedial activities result in changes to the distribution
of contamination within the survey unit, and site-specific
parameters used during final status survey planning
may need to be reestablished following remediation
• Obtaining updated values for these critical parameters
should be considered when planning a remedial action
support survey
copyright 2010
- 32 -
Ameriphysics, LLC
Radiological Surveys
Preliminary Considerations
• Selection of survey instrumentation and analytical
techniques are typically based on a knowledge of the
appropriate DCGLs, because remediation decisions are
made based on the level of the residual contamination as
compared to the DCGL
• Exposure rate measurements may be needed to assess
occupational and public health and safety
• The location of underground utilities should be considered
before conducting a survey to avoid compounding the
problems at the site
copyright 2010
- 33 -
Ameriphysics, LLC
Radiological Surveys
Preliminary Considerations
• Adequacy of Historical Site Assessment
• Designed to confirm HSA conclusions
• Scaling factors
• Release potentially non-impacted areas
• Use of GPS
• Serves as a guide for the final or release survey
• Adequate for Job Safety Analysis
• Regulatory agency may request outputs (reports)
copyright 2010
- 34 -
Ameriphysics, LLC
Radiological Surveys
Survey Planning
• Types of samples and measurements (systematic,
random, biased)
• Required sensitivity of instruments
• Number of samples and measurements
• Sample and measurement location
• Types of analyses
• Data validation and QC/QA
• Data reporting
copyright 2010
- 35 -
Ameriphysics, LLC
Radiological Surveys
Instrument Selection
• Radiation type and energy
• Minimum Detectable Activity (or Concentration)
• Instrument measurement efficiency
• Scaler or rate meter
• Qualitative vs. quantitative data
• New technologies
copyright 2010
- 36 -
Ameriphysics, LLC
Radiological Surveys
copyright 2010
- 37 -
Ameriphysics, LLC
Radiological Surveys
copyright 2010
- 38 -
Ameriphysics, LLC
Radiological Surveys
copyright 2010
- 39 -
Ameriphysics, LLC
Radiological Surveys
Low background
alpha-beta
counters
copyright 2010
Gamma
spectroscopy
- 40 -
Ameriphysics, LLC
Radiological Surveys
copyright 2010
- 41 -
Ameriphysics, LLC
Radiological Surveys
copyright 2010
- 42 -
Ameriphysics, LLC
Radiological Surveys
Positioning Systems
• Allows “exact” location to be recorded
properly each time a sample is taken
• Use of traditional map- spotting
techniques are slow and require trained
personnel
• Modern positioning techniques: global
positioning system (GPS) and
microwaves, ultrasound and laser
ranging systems are preferable
copyright 2010
- 43 -
Ameriphysics, LLC
Radiological Surveys
copyright 2010
- 44 -
Ameriphysics, LLC
Radiological Surveys
GammaCamTM
• Both a two- and a three –
dimensional GammaCam system
have been developed
• Provides remote 2D or 3D
information on position and relative
strengths of gamma-ray radiation
fields
• Remote operation minimizes
worker exposure, and
• Provides easy to read 2D or 3D
color images of gamma radiation
fields over black and white image
copyright 2010
- 45 -
Ameriphysics, LLC
Radiological Surveys
In Situ Object Counting
System (ISOCS)
copyright 2010
- 46 -
•
Field deployable gamma
spectroscopy
•
Real-time in situ, non-intrusive
characterization
•
Broad energy range
•
Monte Carlo modeling in place of
conventional source calibrations
•
Ability to model complex geometries
•
Reduced worker exposure, and
•
70% cost savings compared to
getting a coring sample followed by
offsite analysis
Ameriphysics, LLC
Radiological Surveys
Pipe ExplorerTM System
• Pneumatically operated air-tight
tubular membrane
• Can tow a variety of radiation
detectors and video cameras
• Able to navigate around elbows
and obstructions
• Contamination doesn’t move with
detectors, eliminating false
readings, and
• More cost effective than
demolition on large jobs
copyright 2010
- 47 -
Ameriphysics, LLC
Radiological Surveys
Surveillance and
Measurement System (SAMS)
• Isotopic identification in handheld detector
• Provides real-time data
• Easy to operate
• Can detect up to 70 (expandable
to 95) radionuclides
• Reduces worker exposure, and
• Capital cost of $10,000 is
recovered after 66 samples have
been analyzed
copyright 2010
- 48 -
Ameriphysics, LLC
Radiological Surveys
Surface Contamination Monitor
• 400 radiation measurements per
square meter
• About 70% cost reduction
compared to surveys with handheld instruments
• 5-6 times faster for beta-gamma
and 2 times faster for alpha
survey, and
• 16 times faster for free release
surveys due to automated report
generation
copyright 2010
- 49 -
Ameriphysics, LLC
Radiological Surveys
Characterization Survey Reporting
• Site characterization and operational history
• Instrumentation and survey procedures
• Findings and results
– Clearly identify contaminant levels and impacted areas
• Data presentation
• Maps and figures
• Supporting information and QA/QC
• Documentation developed to support regulator and
stakeholder review for license release
copyright 2010
- 50 -
Ameriphysics, LLC
Other Considerations
• Chemical processes identified from HSA
• Typical ACM, PCB, lead-paint and mold
– Based on construction materials and time
period of construction
• ES&H for sampling activities – proper PPE
• Mindful of disposal site requirements for
materials
copyright 2010
- 51 -
Ameriphysics, LLC
Other Considerations
XRF Analysis
• Hand-held battery-operated unit
• Can analyze 25 elements
• Stores up to 3,000 data points
• Results available in 20 seconds
• 96% cost savings compared to
sample and analysis by
laboratory, and
• Capital cost of $25,000 is
recovered after only 20 samples
copyright 2010
- 52 -
Ameriphysics, LLC
Summary
• Successful characterization requires
investigation and planning
• Ensure that all potential areas of contamination
(all media and pathways) are investigated
• Select the proper tools and methods for the
investigation
• Review and revise as needed based on results
copyright 2010
- 53 -
Ameriphysics, LLC
References
• EPA 1994 – Guidance for the Data Quality
Objectives Process
• DOE 1994 – Decommissioning Handbook
• IAEA 1997 – Radiological Characterization of
Shutdown Nuclear Reactors for
Decommissioning Purposes – IAEA TRS #389
• NRC 2000 – MARSSIM (NUREG-1575, Rev 1)
• ASME 2004 – Decommissioning Handbook
copyright 2010
- 54 -
Ameriphysics, LLC
Characterization Surveys and
Early Site Investigations
Tom Hansen, CHP, PMP
Ameriphysics, LLC
[email protected]