1. ATTENUATION OF RADIATION DAMAGE AND NEUTRON FIELD IN RPV WALL (Plans and preliminary results)
Milan Brumovsky, Milos Kytka, Milan Marek, Petr Novosad
V.N.Golovanov, V.V.Lichadeev, V.M.Raetsky, A.L.Petelin, V.N.Lyssakov
Author: M.Brumovský

2. IAEA TECHNICAL CO-OPERATION PROJECT
CO-ORDINATOR :
NUCLEAR RESEARCH INSTITUTE REZ plc
IRRADIATION REALISATION :
RIAR, DIMITROVGRAD
TESTING SPECIMENS :
PROJECT ANALYSIS AND EVALUATION:
Author: M.Brumovský

3. PURPOSE OF THE EXPERIMENT
Radiation damage in reactor pressure vessel wall (RPV) is usually determined on the basis of neutron field calculations and experiments from surveillance specimen programme testing. However, it is known that neutron spectrum is changing through the RPV wall but no direct correlation exist between neutron damage and neutron spectrum.
Thus, real radiation damage through RPV wall can be determined by a large scale experiment of mock-up type only where changes in material properties through the vessel wall are determined and connected simultaneously with changes in neutron field in specimens locations.
Author: M.Brumovský

4. TECHNICAL SPECIFICATION OF THE EXPERIMENT
Neutron fluence on inner mock-up surface – approx. 6 x 1023 m-2 (En larger than 0.5 MeV),
(approx.4 x 1023 m-2 (En larger than 1 MeV),
in the location of test specimens (i.e. in one specimen layer) the maximum difference should not be larger than 15 % in neutron flux between layer centre and layer sides/boundaries
Irradiation temperature – 288 +/- 10 °C throughout whole specimen block
Author: M.Brumovský

5. NEUTRON DOSIMETRY
Neutron dosimetry should be assured to characterise neutron field (fluence and spectrum) in the whole specimens block in all three directions.
TEMPERATURE MEASUREMENTS Temperature through the specimens block should be realised by a set of thermocouples located in typical locations – outer surfaces as well as in the block centre. Temperature should be continuously measured and in agreed time intervals recorded.
Author: M.Brumovský

6. IRRADIATED SPECIMENS WWER-1000 IAEA REFERENCE STEEL JRQ
BASE METAL :
SPECIMENS FROM MIDDLE HALF OF THICKNESS
(I.E. ACCORDING TO ACCEPTANCE TESTS)
SPECIMENS FROM ALL LAYERS OF THE WHOLE THICKNESS
WELD METAL
IAEA REFERENCE STEEL JRQ
PWR RPV MATERIALS
BASE METAL
Author: M.Brumovský

7. Author: M.Brumovský

8. TYPE OF SPECIMENS
-      Charpy V-notch impact specimens
-     Pre-cracked Charpy size static fracture toughness specimens
-     Instrumented hardness specimens (for determination of tensile properties)
TOGETHER
809 IRRADIATED SPECIMENS
Author: M.Brumovský

9. IRRADIATION IRRADIATION WAS PERFORMED IN NIIAR – REACTOR RBT-6
IRRADIATION FACILITY „KORPUS“
IRRADIATION IN CYCLES
NEUTRON FLUENCE ON THE FIRST LAYER
 (7 – 8) x 1023 m-2 (E > 0.5 MeV)
MEAN IRRADIATION TEMPERATURE
(286  6) OC
Author: M.Brumovský

10. IRRADIATION ASSEMBLY „KORPUS“ ORIGINAL DESIGN
Author: M.Brumovský

11. REAL IRRADIATIONS TWO IRRADIATION CAPSULES: CZR-1 AND CZR-2
2 IRRADIATION BLOCKS
IRRADIATION BLOCK:
18 LAYERS
EITHER 9 CHARPY-SIZE SPECIMENS
OR UP TO 36 INSERTS (10X10X13.75 mm)
Author: M.Brumovský

12. CONFIGURATION OF THE EXPERIMENT
Author: M.Brumovský

13. NEUTRON MONITORS
Assembling of 120 capsules with 600 NRI fluence monitors and 600 RIAR monitors, their installation into the plates of the ampoule
Neutron fluence monitors are installed in plates under block B, between blocks B and C and above block C. The capsules also contain RIAR monitors
Author: M.Brumovský

14. Capsules location in the holes of monitor plates No.2, 3, 4.
Author: M.Brumovský

15. TEMPERATURE MEASAUREMENT
Installation of 72 thermocouples:
Specimens of block B are installed on the second layer of the ampoule, and specimens of block C – on the third layer. On the 1st and 4th layers there are simulators. Location of the specimens in blocks B and C corresponds to the diagram proposed by NRI. The notches of Charpy specimens view the reactor core.
Author: M.Brumovský

16. LOCATION OF THERMOCOUPLES
Author: M.Brumovský

17. REAL IRRADIATIONS EXPERIMENT CZR- 1 (BLOCKS B + C) BLOCK B:
15Kh2NMFAA-BM – ¼ OF THICKNESS
15Kh2NMFAA-WM
BOTH IN 5 DEPTHS
IAEA JRQ as reference – ¼ OF THICKNESS
BLOCK C:
ASTM A 533-B – BM
ASTM A 533-B – WM
Author: M.Brumovský

18. Temperature change over thickness of samples blocks B (1,2) and C (3,4,5). 1, 4 - Charpy samples with index J, 2, 5 - samples with other indices and, 3 - Charpy samples with index A; 6 - average irradiating temperature value, 7 и 8 - bounds of the range 280<Т<290 0С.
Author: M.Brumovský

19. REAL IRRADIATIONS EXPERIMENT CZR- 2 (BLOCKS A + D) BLOCK A:
15Kh2NMFAA-BM – THROUGH THICKNESS
IAEA JRQ as reference – ¼ OF THICKNESS
BLOCK D:
IAEA JRQ – THROUGH THICKNESS
IAEA IRQ – 1/4 OF THICKNESS
Author: M.Brumovský

20. Temperature change over thickness of sample blocks A (1,2) and D (3,4)
Temperature change over thickness of sample blocks A (1,2) and D (3,4). 1 - samples with index A, 2 - samples with index R, 3 - samples wth index J, 4 - samples with index R; 5 - average irradiating temperature value, 6 and 7 - bounds of the range 280<Т<290 0С.
Author: M.Brumovský

21. COMPARISON OF NEUTRON FLUENCES IN BOTH EXPERIMENTS
Author: M.Brumovský

22. COMPARISON OF NEUTRON FLUENCES WITH DIFFERENT NEUTRON ENERGIES
Author: M.Brumovský

23. SPECTRAL INDEXES
Author: M.Brumovský

24. TRANSITION TEMPERATURES OF JRQ STEEL
Author: M.Brumovský

25. TYPICAL CHARPY CURVE
Author: M.Brumovský

26. PRELIMINARY CONCLUSIONS
IRRADIATION EXPERIMENTS PERFORMED SUCCESSFULLY
TARGET NEUTRON FLUENCE AND IRRADIATION TEMPERATURES REACHED
PRELIMINARY DISTRIBUTION OF NEUTRON FLUENCES AND ENERGY SPECTRA OBTAINED
SOME DISCREPANCIES WITH RG 1.99 FOUND
DETAILED NEUTRON SPECTROSCOPY AND CALCULATIONS IN PROGRESS - WILL BE FINISHED TILL 12/2005
MECHANICAL TESTING IN PROGRESS – PLANNED TO BE FINISHED TILL 12/2006
Author: M.Brumovský