ATTENUATION OF RADIATION DAMAGE AND NEUTRON FIELD IN RPV WALL ( Plans and preliminary results)

04/19/23 Author: M.Brumovský1

Nuclear Research Institute Řež plc



ATTENUATION OF RADIATION DAMAGEAND 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



04/19/23 2Author: M.Brumovský

IAEA TECHNICAL CO-OPERATION PROJECT

CO-ORDINATOR :NUCLEAR RESEARCH INSTITUTE REZ plc

IRRADIATION REALISATION :RIAR, DIMITROVGRAD

TESTING SPECIMENS :NUCLEAR RESEARCH INSTITUTE REZ plc

RIAR, DIMITROVGRADPROJECT ANALYSIS AND EVALUATION:

NUCLEAR RESEARCH INSTITUTE REZ plc




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.




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




NEUTRON DOSIMETRY• Neutron dosimetry should be assured to

characterise neutron field (fluence and spectrum) in the whole specimens block in all three directions.

TEMPERATURE MEASUREMENTSTemperature 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.




IRRADIATED SPECIMENS• WWER-1000

– 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• SPECIMENS FROM MIDDLE HALF OF THICKNESS

(I.E. ACCORDING TO ACCEPTANCE TESTS)

• SPECIMENS FROM ALL LAYERS OF THE WHOLE THICKNESS

• PWR RPV MATERIALS– BASE METAL

– WELD METAL




-150

-125

-100

-75

-50

-25

0

25

0 25 50 75 100 125 150 175 200 225

distance from the surface of the plate in mm

tem

per

atu

er i

n °

C

1/4-T 3/4-TTT41J

T0

-150

-125

-100

-75

-50

-25

0

25

0 25 50 75 100 125 150 175 200 225

distance from the surface of the plate in mm

tem

per

atu

er i

n °

C

1/4-T 3/4-TTT41J

T0

Figure 2. Charpy T41J and T0 versus distance from the surface in Block 5JRQ22.




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




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




IRRADIATION ASSEMBLY „KORPUS“ORIGINAL DESIGN




REAL IRRADIATIONS

• TWO IRRADIATION CAPSULES:– CZR-1 AND CZR-2

• IRRADIATION CAPSULE:– 2 IRRADIATION BLOCKS

• IRRADIATION BLOCK:– 18 LAYERS

• EITHER 9 CHARPY-SIZE SPECIMENS• OR UP TO 36 INSERTS (10X10X13.75 mm)




CONFIGURATION OF THE EXPERIMENT

CORE

Capsule Capsule Capsule Capsule

Capsule Capsule

CZR - 2 CZR - 1

Imitator Capsule Capsule Imitator

Imitator Imitator Capsule Capsule Imitator Imitator




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




Core

1 10 6 1

2

3 8

4

5 11 2 Front plate

6

7 5

8

9 12 7 3

1

2

3

4

5

6

7

8

9

10 22 18 13

11

12 20

13

14 23

14 Back plate

15

16 17

17

18 24 19 15

Capsules location in the holes of monitor plates No.2, 3, 4.




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.




LOCATION OF THERMOCOUPLES

CO

RE

2 8 4 , 5 2 8 7 , 8 2 8 6 , 3 2 8 8 , 9 - 2 7 9 , 92 5 2 9 2 7 3 1 3 5 3 3

2 9 9 , 7 2 8 5 , 32 9 4 , 0 5 2 9 7 , 7 2 9 4 , 8 1 1 2 9 4 , 7

1 3 7 9

1 3 1 7 1 5 1 9 2 3 2 12 8 5 , 0 - 2 9 2 , 5 2 8 0 , 9 2 7 6 , 8 2 9 1 , 1

2 8 4 , 5 2 8 7 , 7 2 8 6 , 4 2 8 8 , 9 2 7 2 , 5 2 7 9 , 82 6 3 0 2 8 3 2 3 6 3 4

2 9 4 , 1 6 2 9 7 , 8 2 9 4 , 7 1 2 2 9 4 , 42 2 9 9 , 7 4 8 2 8 5 , 3 1 0

1 4 1 8 1 6 2 0 2 4 2 22 8 5 , 0 2 8 6 , 0 2 9 2 , 5 2 8 0 , 9 2 7 6 , 9 2 9 1 , 2

Stor

ey 2

St

orey

3




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

– BOTH IN 5 DEPTHS• IAEA JRQ as reference – ¼ OF THICKNESS




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.

279280281282283284285

286287288289290291

0 5 10 15 20

Distance from the front heaters block, cm

Tem

pera

ture

of

sam

ples

laye

r, 0 C

1

2

3

4

5

6

7

8




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




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.

279

280

281

282

283

284

285

286

287

288

289

290

291

0 5 10 15 20

Distance from the front heaters block, cm

Tem

pera

ture

of

sam

ples

laye

r, 0 C

1

2

3

4

5

6

7




COMPARISON OF NEUTRON FLUENCES IN BOTH EXPERIMENTS

F (0.5 MeV)

F = 9,0527e-0,1486x

R2 = 0,9998

F = 7,8368e-0,1486x

R2 = 0,9998

0

1

2

3

4

5

6

7

8

9

0 20 40 60 80 100 120 140 160 180 200x, mm

F, 1

0^

23

m/2

Block B

Block C

Block A

Block D

Exponenciální (Block B)

Exponenciální (Block D)




COMPARISON OF NEUTRON FLUENCES WITH DIFFERENT NEUTRON ENERGIES

F(0,5 MeV) = 9,0527e-0,0149x

F(1 MeV) = 5,2499e-0,0153x

F(3 MeV) = 1,0205e-0,1956x

F(1 MeV)/RG 1.99 = 5,2499e-0,0094x

0

1

2

3

4

5

6

7

8

9

0 20 40 60 80 100 120 140 160 180 200x, mm

F, 1

0^

23

m-2

B(0,5 MeV)

C(0,5 MeV)

A(0,5 MeV)

D(0,5 MeV)

A,D(1 MeV)

A,D(3 MeV)

RG 1.99(1 MeV)

Exponenciální (B(0,5 MeV))

Exponenciální (A,D(1 MeV))

Exponenciální (A,D(3 MeV))

Exponenciální (RG 1.99(1 MeV))




SPECTRAL INDEXES

0

5

10

15

20

25

0 50 100 150 200x, mm

SP

EC

TR

AL

IND

EX

0.5/1 MeV

0.5/3 MeV

Lineární (0.5/1 MeV)

Exponenciální (0.5/3 MeV)




TRANSITION TEMPERATURES OF JRQ STEEL

-160

-140

-120

-100

-80

-60

-40

-20

0

20

40

60

80

100

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230

MATERIAL DEPTH, mm

TT

41J,

°C

TT_41J UNIRRADIATED

TT_41J IRRADIATED

6JRQ24 TT_41J UNIRRAD




TYPICAL CHARPY CURVE

0

25

50

75

100

125

150

175

200

-130 -90 -50 -10 30 70 110 150 190 230 270

Temperature

En

erg

y [

J]

LAYER 4 - RIAR

LAYER 4

LAYER 4 - NRI




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

ATTENUATION OF RADIATION DAMAGE AND NEUTRON FIELD IN RPV WALL ( Plans and preliminary results)

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