Irradiation Testing of Research
Reactor Materials at Low
Temperature (<100℃) at HANARO
Bong Goo Kim, Jong Myeong Oh, Sung Jae Park, Seong Woo Yang,
Myoung-Hwan, Byung-Chul Lee and Tae Kyu Kim
Oct. 23, 2012
5th ISMTR, Oct. 22 – 25, 2012, Columbia, Mo, USA
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Contents
Introduction to HANARO
Irradiation device for material irradiation
testing at HANARO
Design and manufacturing of capsule
Irradiation data & future works
Summary
2
Introduction to HANARO
3
Status of Nuclear Plants in Korea
Present Nuclear Power Plants in Korea (2012. 10.)
- 19 PWRs, 4 CNADUs in operation
- 9 PWRs under construction
In operation
- 8 PWRs in the plan
Under const.
Planning
Daejeon Area
- KAERI(HANARO)
- KEPCO NF (KNF); Fuel Fabrication
HANARO
Fuel fabrication facility
SEOUL
Samchuk
Uljin
Youngdeok
Daejeon
Wolsung 4 CANDUs
Younggwang
Gori
Kijang
Research Reactor
4
HANARO (1)
General Design Features of HANARO
Reactor Type
Thermal Power
Thermal Neutron Flux (peak)
Fast Neutron Flux (peak)
Fuel Element
Coolant
Moderator
Reflector
Core Cooling
Absorber Material
OR
Open-Tank-In-Pool
30 MW
5.4×1014 n/cm2-s (E<0.625 eV)
2.1×1014 n/cm2-s (E>1.0 MeV)
19.75% enrichment, U3Si-Al Matrix, Al Clad
H2O
H2O/D2O
D2O
Upward Forced Convection Flow
Hafnium
Neutron Flux of Vertical Holes
Location
Core
Plan view of HANARO
Ave. Neutron flux(n/cm2•sec)
Hole
Name
No.
Fast
CT
IR
OR
1
2
4
1.4×1014
1.3×1014
1.2~1.5×1013
LH*
NTD*
1
2
IP
17
4.7×1011
7.7×1010
~1.0×1011
2.0×109
~1.5×1012
Reflector
Thermal
Remarks
3.0×1014
Fuel/Mat. Irradiation
2.7×1014
and RI Production
2.0~2.5×1014
7.4×1013
Fuel/Mat. Irradiation ,
3.7~4.0×1014 RI Production and
Neutron activation
1.8×1013
Analysis, Neutron
~1.3×1014
transmutation doping
* LH; Large Hole in the Reflector, NTD; Neutron Transmutation Doping
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HANARO (2)
Reactor hall
Core
CNRF
6
Experimental Facilities in HANARO
Vertical Test Holes
Multi-purpose research reactor; 32 vertical holes & 7 horizontal beam ports
Installed
IR1
CT, IR2
OR
IP, LH
HTS
PTS
NTD
CNS
:
:
:
:
:
Fuel Test Loop
Capsule Irradiation & RI Production
Capsule Irradiation & RI Production
RI Production
Hydraulic Transfer System
for RI Production
: Pneumatic Transfer System
for Neutron Activation Analysis
: Neutron Transmutation Doping
of Silicon
: Cold Neutron Research Facility
Plan view of HANARO
PTS #1
PTS #2
PTS #3
Horizontal Beam Ports
Installed
ST1 : PGNAA, RSI Test Station, PNS
ST2 : High Resolution Powder Diffractometer,
Four Circle Diffractometer
ST3 : Neutron Reflectometer-Vertical
NR : Neutron Radiography Facility
CN : Small Angle Neutron Spectrometer
IR : BNCT & Dynamic Radiography
IP
PTS
OR
Under-development
ST3 : Neutron Reflectometer-Horizonal
High Intensity Powder Diffractometer
ST4 : Triple Axis Spectrometer (thermal)
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Irradiation device for material
irradiation testing at HANARO
8
Instrumented Capsule for Materials(1/2)
Charpy
Tube
5th stage
Design Characteristics
R-CT
경도/인
Hardnes
s/Tensile
장
ü
ü
ü
ü
ü
ü
ü
Total Length : ∼6 m ( 60 mm D x 870 mm H)
5 Stages Independent Temp. Control
Max. Temp. Control : Up to 500℃
Atmosphere : 1 atm∼3×10-3 torr (He, Dry)
Instrumentations : T/Cs, Small heaters, F/Ms
Available Space(Max.): 40 mm D × 600 mm L
Available Specimen : Tensile, Charpy, R-CT,
SP, Tube, hardness, PCVN, MBE, TEM, etc.
Applications
ü Material Tests
- Reactor Pressure Vessel
- Reactor Core Materials
- CANDU Pressure Tube Materials
ü Safety and Integrity-Related Tests
ü Study on the extension of reactor lifetime
ü Industry Application Material Tests
ü Fundamental Research
9
Instrumented Capsule for Materials(2/2)
Geometrical shape of the instrumented capsules for the material
irradiation tests, which consists of the bottom guide structure, the main
body, the protection tube, and the guide tube
Typical schematic view of the holder and its section including the
thermocouple positions ; A total of 12 thermocouples are used (three for
Stages 1 and 3, and two for Stages 2, 4 and 5), and they are installed on
the top and bottom edges of the specimen inserted in hole #3 and/or #4.
Several typical specimens for the irradiation testing
Bottom
guide
Main
body
Guide
Tube
Protection
Tube
TEM (case)
Tensile
0.4T CT
Small Tensile
Hv / Microstructure
10
Instrumented Capsule for Nuclear Fuel
Design Characteristics
ü
ü
ü
ü
ü
ü
Total Length : 5,000 mm
Diameter of Outer Tube : 56 mm
Length of Outer Tube : 730 mm
3 Test Fuel Rods : 200 mm long
Instrumentations : TCs, LVDTs, SPNDs
Control of Irradiating Temperature Using
Mixed Gas(He/Ne)
Applications
ü Fuel Pellet Irradiation Test
- Advanced PWR Fuel (Fuels for SFR, VHTR)
ü Fuel Design Data Production
- Surface Temperature of Fuel Pellet
- Internal Pressure of Element Fuel Rod
- Deformation of Fuel Pellet
ü Fundamental Research
11
Design and manufacturing of Capsule
12
Capsule Design
The geometrical shape of the main body and a typical cross section for
arbitrary including the specimens with three different shapes (Type1;
Circular, Type2; Rectangular, Type3; Square)
The specimens are basically canned by a tube of 1 mm in thickness
made of stainless steel. Also, there are two kinds of canning tubes; a
closed tube for the graphite circular specimens (Type1 #1&2) and an
opened tube with side slots to contact between the specimen and the
cooling water (Type1 #5, Type2&3).
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Nuclear analysis
Assuming that a capsule is irradiated at the CT test hole of HANARO,
neutron fluxes and heat generation rates of specimens at 30 MW thermal
power of HANARO were evaluated using the MCNP5 code.
The following figures show the geometric models of the capsule loaded
in the core for the nuclear analysis. The reactivity effect owing to the
capsule loading in the core was then analyzed to confirm the reactor
safety. The expected neutron fluxes at the specimens were evaluated to
satisfy the required value.
(a) cross-section at CT test hole
(b) axial-section of specimens
(c) axial-section of a capsule at CT test hole
HANARO Core Model (MCNP 5)
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Thermal analysis (1/2)
Three models;
- 2-dimensional model of the quarter sections for all specimens
- axi-symmetric model for circular specimens (Type1 #1,2,5)
- 3-dimensional model for rectangular and square specimens (Type2~3
#3,4,6)
Boundary conditions
- the temperature (40 ℃) of the cooling water and heat transfer
coefficient (h = 30.3×103 W/m2 ℃) at the outer surface of the canning
tube
Axi-symm.
Stage
5 (Top)
3 (Mid)
(a) 2D model
(b) Axi-symm. Model
Typical models of canned graphite specimen
1 (Bottom)
Specimen
No.
1&2
3&4
5-1
5-2
6
1&2
3&4
5-1
5-2
6
1&2
3&4
5-1
5-2
6
Shape
Material
Cir
Rect
Cir
Cir
Squ
Cir
Rect
Cir
Cir
Squ
Cir
Rect
Cir
Cir
Squ
Gr
Zr
Be
Zr
Zr
Gr
Be
Be
Zr
Be
Gr
Be
Be
Zr
Be
2D
or 3D
Max.
Max.
Min.
90.2
58.4
40.5
47.9
49.8
153.6
42.2
41.1
60.8
41.2
122.1
41.6
40.6
53.6
40.9
85.0
58.4
41.1
48.0
49.8
142.0
42.2
42.7
60.9
41.2
114.1
41.6
41.7
53.6
40.9
71.5
40.0
40.0
40.0
40.0
112.0
40.0
40.0
40.0
40.0
92.6
40.0
40.0
40.0
40.0
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Thermal analysis (2/2)
The temperature distribution for the canned graphite
specimen at stage 5 using the 2D model, and the profile
in the radial direction at the position.
The maximum temperature at the specimen is 90.2 ℃,
and rapidly decreased at the gap between the specimen
and canning.
The results of the canned graphite specimen using an
axi-symmetric model.
The closed canning tube has a similar temperature with
that of the cooling water. The temperature in the radial
direction is uniformly distributed without the gradient,
similar to the 2D model. In this case the temperature
difference between the top and bottom along the center
of the specimen in the axial direction is about 13 ℃.
The maximum value is 85 ℃ at the top of the specimen
center, and the minimum is 71.5 ℃ at the bottom, which
can increase the heat transfer owing to the direct
contact between the specimen and canning tube.
The temperature distribution of the zircaloy-4
specimens with rectangular and square shapes at stage
5 and of the zircaloy-4 specimens with rectangular
shape at stage 3 using the 3D model.
The maximum temperature at stage 3 is 63.3 ℃ in these
figures.
Type2 at stage 5
Type2 at stage 3
16
Fluence monitors
Typical flux wires (Iron, nickel, and titanium) and
a fluence monitor (F/M) container (pure aluminum)
used for irradiation tests of materials at HANARO.
A new type of fluence monitor (F/M) container
contains wires encapsulated in Al 6061 tube. The
encapsulation is about 18 mm long with an outer
diameter of 6 mm, and is engraved with a unique
identification number. Wires are also placed
within holes drilled of each pure aluminum
sample holder or within the tube, which is
directly exposed to the coolant. A new type of
F/M container with fluence wires such as Fe, Ni,
Ti and Nb can be easily assembled under a
helium atmosphere.
Fluence Wires
Al Container
A new type of F/Ms are also axially and radially
located at each stage in the capsule. After
irradiation testing of the capsule, the radial and
axial fluence distribution will be estimated after
irradiation testing.
17
Capsule Assembling
A mockup capsule was fabricated to
carry an out out-of-pile test.
After carrying out the out-of-pile
test using the mock-up capsule,
compatibility and requirements,
such as pressure drop (> 200 kPa at
of 19.6 kg/sec of rated flow) and
vibration (less than 300 μm at 110%
of rated flow) were verified.
Two capsules were fabricated to
load in test holes, CT and IR, of
HANARO.
These capsules were loaded and
carrying out the irradiation testing
at the test holes from September
2012 at HANARO.
Mockup capsule for the out-of-pile test
Two capsules for irradiation testing
18
Irradiation data
HANARO Power (30 MW)
11M-20K (CT test hole)
HANARO Power (30 MW)
11M-21K (IR2 test hole)
IR2 CT
19
Future works
Tensile tests, hardness tests and measurements of thermal
diffusivity of unirradiated graphite, beryllium, and zircaloy4 are carrying out.
The comparison of measured temperatures of specimens
with the calculated temperatures of specimens is
proceeding.
After irradiation testing, PIE (measurements of irradiation
growth, tensile strength, hardness, swelling, thermal
diffusivity) including an evaluation of fluence will be
performed.
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Summary
21
Two capsules were designed and fabricated to irradiate materials
using reflector materials in a research reactor such as graphite,
beryllium, and zircaloy-4 at low temperature (<100℃).
The thermal analysis results with FE models show in good
agreement with each another, except for the canned graphite
specimens having the difference of 12℃ between 2D and axisymmetric models.
The temperatures of beryllium and zircaloy-4 specimens at all
stages are 40 to less than about 65 ℃. The zircaloy-4’s
temperatures are higher than those of the beryllium specimens.
New type of fluence monitor (F/M) container was designed and
prepared for irradiating nuclear materials and reflector materials
of research reactors.
Two capsules including specimens using research reactor were
started to irradiate at the test holes from September 2012 at
HANARO.
The measured temperatures of specimens during irradiation
and/or after irradiation will be compared with the calculated
temperatures.
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