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BALAKOVO-3 VVER-1000
1. Name of Experiment:
------------------
Balakovo-3 VVER-1000 Ex-vessel Neutron Dosimetry Benchmark
2. Purpose and Phenomena Tested:
----------------------------
The reliable determination of RPV neutron field parameters is needed for an
evaluation of the radiation embrittlement of RPV steel. Calculational
procedures used for the determination of neutron fluence, fluence rate and
spectrum at critical points of Reactor Pressure Vessel (RPV) of Russian design
water-water-power-reactor with electrical power 1000 MW (VVER-1000) are to be
validated.
To solve this task, a neutron dosimetry experiment using activation and
fissionable detectors was carried out at Russian NPP Balakovo, unit 3
(Balakovo-3), during cycle 5, from March 1994 to January 1995. The detectors
were installed in the ex-vessel cavity near the outer RPV surface.
The purpose was to: (1) evaluate the reliability of ex-vessel dosimetry
measurement techniques, (2) provide data for a 3D full scale validation of
neutron transport calculations, (3) develop the regulatory guides for a RPV
ex-vessel neutron dosimetry procedure.
The area of neutron transport investigation extends from the reactor core
center to the biological shield, from the core bottom to the top, and includes
60-degree azimuthal sector (Fig. 1).
3. Description of Source and Experimental Configuration:
----------------------------------------------------
The details are available in ref. [1].
The activation detectors were situated in aluminum capsules which were attached
to the experimental rack. This experimental rack had azimuthal and axial rods
which were situated in the cavity near the outer surface of the pressure vessel
on the same reactor radius 228 cm from the center. Detail information includes
capsules coordinates, construction and material data, and also the arrangement
of the detector sets in the capsules.
The reactor configuration includes:
- the design description of the VVER-1000 reactor,
- the azimuthal-radial geometrical approximation of the reactor (r-theta model),
- axial-radial geometrical approximation of the reactor (r-z model),
- material compositions of the modeled zones and temperatures of the water
layers,
- nuclear concentrations of the zones.
The neutron source is a 3D power reactor core with fuel assemblies of hexagonal
form and with the same form arrangement of the fuel pins. The fuel is fresh and
burnup uranium dioxide. The 5th fuel cycle was arranged with fresh fuel on the
core periphery which had the initial 235U enrichment of 4.4 %. The irradiation
period was 170.1 Effective Full Power Days (EFPD). The detail fission source
description includes:
- reactor operating data during the detector irradiation time (total power
history, 2D assemblies power distributions, coolant temperature variations),
- time-dependent neutron-physical parameters of the core:
- 2D and 3D assemblies power distributions
- 2D and 3D assemblies burnup distributions
- 3D pin-to-pin power distributions of the peripheral assemblies
- 3D pin-to-pin burnup distributions of the peripheral assemblies
- heavy metal concentration in assemblies
- burnup-dependence of neutron emission.
To estimate the composition of the fuel as a function of burnup (e.g. using MCNP
and Monteburns) the following information can be usefull in addition to the one
provided in ref. [1]:
- Balakovo-3 cooling water with boron acid H3BO3:
EFPD = 0: Concentration H3BO3 5.2 g/kg H2O
EFPD = 170.1: Concentration H3BO3 2.7 g/kg H2O
- Average fuel temperature per VVER-1000 Full Power is 830 C degrees.
4. Experimental data and Uncertainties:
------------------------------------
As experimental data to be compared with calculations were chosen the
End-Of-Irradiation Activities (EOIAs). The analysis of data measured by the
participants of Balakovo-3 experiment resulted in reference absolute EOIAs sets
for capsule positions at 9.4°, 32°, 37°, 47° and 55.8° azimuth angles. The
following dosimetry reactions were analyzed: 237Np(n,f)137Cs, 238U(n,f)137Cs,
93Nb(n,n')93mNb, 58Ni(n,p)58Co, 54Fe(n,p)54Mn, 46Ti(n,p)46Sc, 63Cu(n,alpha)60Co,
93Nb(n,gamma)94Nb.
The experimental results include also set of evaluated Reaction Rates (RR) and
very detailed ex-vessel azimuthal and axial distributions of the 54Fe(n,p)
reaction rates.
The following centers took part in measurements by their own activation
detectors, and results of which were used in the intercomparison:
- SEC NRS of GOSATOMNADZOR of Russia, Moscow, Russia,
- Research Institute of Atomic Reactors (RIAR), Dimitrovgrad, Russia,
- Moscow Institute of Engineering Physics (MIFI, Moscow) in cooperation with
Institute of Physics Technical and Radio Technical Measurements (VNIIFTRY,
Mendeleevo), Russia,
- Russian Research Center "Kurchatov Institute" (KI), Moscow, Russia,
- Forschungszentrum Rossendorf e.V. (FZR), Dresden, Germany,
- The NRG, formed the Netherlands Energy Research Foundation (ECN), Petten,
The Netherlands,
- SKODA, Nuclear Machinary, Plzen, Czech Republic.
Niobium-93 measurement data were resulted from "robin round" intercomparison,
in which the same niobium foils were analyzed.
Additional centers took part in this stage of intercomparison:
- SIEMENS AG KWU, Erlangen, Germany,
- VTT Chemical Technology, Espoo, Finland,
- Institute for Nuclear Research and Nuclear Energy (INRNE), Sofia, Bulgaria,
- SCK(CEN Fuel Research, Mol, Belgium.
The detector activities were measured in participant own laboratories by using
their own measurement techniques. The results intercomparison procedure was a
"blind test" one. The uncertainty of reference results reflects as the
statistical discrepancy of results of different participants (in case of
representative statistic) and an evaluated uncertainty of participant data (in
case of two values in the intercomparison).
5. Comparison of Measurements and Calculations:
-------------------------------------------
The measured data are accompanied with neutron transport calculated results.
The reference measured EOIAs (E) were compared with calculated results (C).
The comparison of E with C resulted from DORT code (Sn method) coupled with
BUGLE-96 library and TRAMO code (Monte Carlo method) with library based on
ENDF/B-VI data are demonstrated by table 1.
Table 1 - Average C/E for Balakovo-3 benchmark
Reaction DORT&BUGLE-96 TRAMO&ENDF/B-VI
237Np(n,f) 0.951 0.918
93Nb(n,n') 0.982 0.937
238U(n,f) 0.986 0.936
58Ni(n,p) 1.069 1.014
54Fe(n,p) 1.097 1.043
46Ti(n,p) 0.974 0.961
63Cu(n,a) 0.998 1.010
6. Special Features:
----------------
1. Experimental reference data obtained by interlaboratory ex-vessel dosimetry
experiment
2. Detailed reactor and neutron source description
3. Interlaboratory neutron transport calculations by Sn and Monte Carlo methods
and intercomparison of results
4. Comparison between calculated and experimental reference data
7. Author/Organizer:
----------------
Organization of the Ex-Vessel Balakovo-3 Exercise:
Scientific and Engineering Center for Nuclear and Radiation Safety (SEC NRS)
of Russian GOSATOMNADZOR, 14/23 Avtozavodskaya ul., 109280 Moscow, Russia;
Forschungszentrum Rossendorf e.V. (FZR), Postfach 510119, 01314 Dresden, Germany.
Compiler of data for Sinbad:
G.I. Borodkin (SEC NRS), B. Böhmer and K. Noack (FZR)
e-mail: borodkin@ntc.asvt.ru
boehmer@fz-rossendorf.de
noack@fz-rossendorf.de
Reviewer of compiled data:
I. Kodeli
OECD/NEA, 12 bd des Iles, 92130 Issy les Moulineaux, France
e-mail: ivo.kodeli@oecd.org
8. Availability:
------------
Unrestricted
9. References:
----------
[1] G. Borodkin, B. Boehmer, K. Noack, N. Khrennikov,
Balakovo-3 VVER-1000 Ex-vessel Neutron Dosimetry Benchmark Experiment,
report for SINBAD project, FZR/SEC NRS, 2002
[2] G.I. Borodkin and O.M. Kovalevich, Interlaboratory VVER-1000 Ex-vessel
Experiment at Balakovo-3 NPP, Report on the 9th International Symposium on
Reactor Dosimetry, 2 - 6 Sep. 1996, Prague, Czech Republic, Report E-147,
1996.
[3] International Workshop on the Balakovo-3 Interlaboratory Dosimetry
Experiment, September 2 - 5, 1997, FZR, Rossendorf, Dresden, Germany.
Minutes on the Workshop.
[4] Borodkin, G. I., Kovalevich, O. M., Barz, H.-U., Böhmer, B., Stephan, I.,
Ait Abderrahim, H., Voorbraak, W., Hogel, J., Polke, E., Schweighofer, W.,
Seren, T., Borodin, A. V., Vikhrov, V. I., Lichadeev, V. V.,
Markina, N. V., Grigoriev, E. I., Troshin, V. S., Penev I., and Kinova, L.
Balakovo-3 Ex-vessel Exercise: Intercomparison of Results, Reactor
Dosimetry: Radiation Metrology and Assessment, ASTM STP 1398,
John G. Williams, David W. Vehar, Frank H. Ruddy and David M. Gilliam,
Eds., American Society for Testing and Materials, West Conshohoken, PA,
2001, pp. 320-327.
[5] G. Borodkin and B. Boehmer, Validation of 3D Synthesis RPV Neutron Fluence
Calculations using VVER-1000 Ex-Vessel Reference Dosimetry Results,
2000 ANS Annual Meeting, June 4-8, 2000, San Diego, California, Transactions
of the ANS, volume 82, 2000, pp. 223-225.
[6] B. Boehmer, J. Konheiser, G. Borodkin and G. Manturov, Testing of Neutron
Data Libraries in Application to Reactor Pressure Vessel Dosimetry, Internat.
Conference on Nuclear Data for Science and Technology, Oct. 7-12, 2001,
Tsukuba, Ibaraki, Japan.
[7] GOSATOMNADZOR of Russia. Safety Guides. Procedure of Neutron Dosimetry on
the Ex-Vessel Surface of VVER of NPP (RB-018-01). (Draft), G.I. Borodkin
et al., November 2001.
10. Data and Format:
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FILE NAME bytes Content
---- ----------- ------ -------
1 balak3-a.htm 16,695 This information file
2 balakovo.pdf 627,029 Reference 1 with the description of Experiment
3 gip-b3.inp 3,109 Input data for GIP cross-section mixing code
4 dort-b3.inp 90,096 Input data for DORT transport code
5 fig1.gif 10,750 Fig. 1: VVER-1000 60-degrees sector with dosimetry
positions for Balakovo-3
6 fig2.gif 23,994 Fig. 2: VVER-1000 radial-axial model used for Balakovo-3
7 fig3.gif 8,611 Fig. 3: 30-degree scheme of VVER-1000 baffle
8 fig4.gif 21,514 Fig. 4: Arrangement and description of VVER-1000 fuel assemblies
9 fig5.gif 7,887 Fig. 5: Numeration of pin positions in VVER-1000 fuel assembly
10 fig6.gif 4,056 Fig. 6: Scheme of capsule in which dosimeters were irradiated
11 figA1.gif 10,260 Fig. A.1: TRAMO input spectra and adjusted spectra
(single spectrum adjustment – SSA, multi spectrum adjustment
– MSA) for two detector positions.
12 figB2.gif 8,219 Fig. B.2: Absolute calculated neutron spectra at 55.8°
ex-vessel position.
13 table 1.1.xls 15,360 Table 1.1: NPP and core design parameters
14 table 1.2.xls 16,384 Table 1.2: Fuel assembly description
15 table 1.3.xls 14,848 Table 1.3: Dosimetry irradiation description
16 table 1.4.xls 16,896 Table 1.4: Material (zone) numbers and compositions
17 table 1.5.xls 14,336 Table 1.5: Densities and chemical compositions
18 table 1.6.xls 14,336 Table 1.6: VVER-1000 baffle channels
19 table 1.7.xls 17,408 Table 1.7: Total power history during detector irradiation
20 table 1.8.xls 16,384 Table 1.8: Nuclear concentration of zones
21 table 1.9.xls 15,360 Table 1.9: Reference Measured absolute End-Of-Irradiation Activities
22 table 1.10.xls 14,848 Table 1.10: Measured absolute End-Of-Irradiation Activities (EOIA)
23 table 1.11.xls 13,824 Table 1.11: Evaluated photofission effects
24 table 2.1.xls 14,336 Table 2.1: Average Relative Standard Deviations for Reference EOIA
25 table 2.2.xls 18,432 Table 2.2: Ratios of calculated-to-measured fuel assembly powers
26 table 2.3.xls 14,336 Table 2.3: Correction factors to account for local power history
effects
27 table A.1.xls 13,824 Table A.1: Calculation Positions
28 table A.2.xls 14,848 Table A.2: Relative Standard Deviations (RSD) for different
spatial points
29 table A.3.xls 14,848 Table A.3: Auto Correlation Matrix and RSD for Point 6
(PVC, theta=9.4)
30 table A.4.xls 14,848 Table A.4: Cross Correlation Matrix for 1/4 RPV thickness position
and a cavity position
31 table A.5.xls 16,896 Table A.5: Fluence and dpa values before and after adjustment
32 table A.6.xls 14,848 Table A.6: Relations between MSA and SSA results for fluence integrals
33 table B.1.xls 14,336 Table B.1: Comparison of calculated fluence rates at 55.8° position.
34 table B.2.xls 14,336 Table B.2: C/E data for 3D synthesis DORT using different libraries.
35 table B.3.xls 14,848 Table B.3: C/E data for 3D synthesis DORT/BUGLE-96t with
different dosimetry files.
36 table B.4.xls 16,384 Table B.4: Absolute evaluated experimental reaction rates and
C/E ratios.
37 table B.5.xls 14,848 Table B.5: C/E results for different calculations.
38 table B.6.xls 14,848 Table B.6: C/E for Cd covered (n,gamma)-detectors (3D synthesis).
39 table B.7.xls 14,336 Table B.7: C/E for bare (n,gamma)-detectors (3D synthesis calculations).
40 FILE_1.DAT 1,782 Assembly burnup per effective full power days (EFPD)
41 File_2.dat 2,354 Emitted neutrons per EFPD interval
42 File_3.dat 16,960 Axial burnup distribution per EFPD
43 File_4.dat 17,154 Relative axial neutron source distributions per EFPD interval
44 File_5.dat 221,170 Pin numbers in assembly
45 File_6.dat 177,872 Pin numbers in assembly
46 File_7.dat 2,597 Total power history during detectors irradiation
SINBAD Benchmark Generation Date: 6/2003
SINBAD Benchmark Last Update: 6/2003
