1

Nodalisation and Visualisation

of VVER440/V213 core

2nd EUMUG

SUJB, Prague

1 – 2 March 2010

Juraj Jančovič, Peter Juriš

jancovic@vuje.sk, juris@vuje.sk

2

Motivation

Approach

Development of a brand new nodalisation

Intensified activities to join CSARP/MCAP

Model verification using RELAP5 code calculations and comparison

with ASTEC code results

Development of in-vessel core behaviour visualisation

Development of a new model for PSA L2 analyses (1471.25 MWt)

Detailed core nodalisation, 3-loop primary circuit model

MELCOR 1.8.5 version of the code used

3

MELCOR 1.8.5 model

Integral model allowing modelling of a scenario from initiating event up to both in-vessel and ex-vessel phase of severe accidents

Capable of source term calculation, including source term time history in time period 0 s – 172 800 s (2 days)

Steam generator tube creep rupture model evaluated

MELCOR 1.8.5 model

4

VVER440 RPV/core

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1. CV004 DOWNCOMMER 2. CV009 LP-BEZ_UO2 3. CV010 DZK_R12_A69 4. CV011 DZK_R3_A69 5. CV012 DZK_R45_A69 6. CV013 DZK_R6_A69 7. CV014 DZK_R7_A69 8. CV015 AZ_R12_A1012 9. CV016 AZ_R3_A1012 10. CV017 AZ_R45_A1012 11. CV018 AZ_R6_A1012 12. CV019 AZ_R7_A1012 13. CV020 AZ_R12_A1315 14. CV021 AZ_R3_A1315 15. CV022 AZ_R45_A1315 16. CV023 AZ_R6_A1315 17. CV024 AZ_R7_A1315 18. CV025 AZ_R12_A1619 19. CV026 AZ_R3_A1619 20. CV027 AZ_R45_A1619 21. CV028 AZ_R6_A1619 22. CV029 AZ_R7_A1619 23. CV040 HZK 24. CV041 PodVekomValec 25. CV042 PodVekomPolgula

9,54 m

CV004

FL049 FL048

11,92 m CV042

13,652 m

CV040

FL028 FL029 FL025 FL026 FL027

7,495 m

CV

029

FL023 FL024 FL020

CV025 CV026 CV027 CV028

FL021 FL022

6,320 m

CV

024

FL018 FL019 FL015

CV020 CV021 CV022 CV023

FL016 FL017

5,390 m

FL010

CV017 CV018

CV

019

FL011 FL012 FL013 FL014

4,563 m

FL

032

FL0

32

FL

034

FL0

34

FL005

CV010 CV011 CV012 CV013

CV

014

FL006 FL007 FL008 FL009

FL

031

FL0

31

FL

033

FL0

33

2,203 m

0,284 m

FL004 CV009

FL046 FL047

10,808 m CV041

REAKTOR

3,9 m

2,4 m

3,9 m

2,4 m

FL108 FL109 CV110

8,472 m

9,872 m

10,368 m

9,996 m

10,244 m

HS00064hemisph.

2,763 m

3,213 m

1,653 m

2,203 m

4,77 m

5,08 m

HS

00

00

1c

HS

00

00

2c

HS00003c

HS00004c

HS00005c

HS00006c 3,663 m

HS

00

06

1c

HS00008c

HS00009c

HS00010c

HS00011c

5,70 m HS00012c

6,01 m HS00013c

CV164

8,968 m

8,472 m

FL165 FL166

8,596 m

8,844 m

HS00014c

HS00015c

HS00016c

HS00017c 7,25 m

6,94 m

6,63 m

HS00021r

HS00022r

HS00023r

HS00024r

HS00025r

1,653 m

HS

00

04

0c

HS

00

04

5c

7,695 m

HS

00

06

2c

9,54 m

HS00043r

HS

00

04

1c

11,636 m

11,845 m

HS

00

04

6c

HS

00

04

7c

HS

00

04

9c

10,9 m

11,44 m

11,84 m

HS

00

04

4c

HS

00

06

3c

HS

00

04

2c

HS

00

05

0c

HS

00

04

8c

12,685 m

12,485 m 13,569 m

12,2 m

HS00051r 12,6 m

4,113 m HS00007c

1,653m

1,653m

FL0

41

FL0

42

FL0

43

FL0

44

5,0m

FL0

38

FL0

38

CV015 CV016

FL0

35

FL0

35

5,0m

6,0m

FL0

36

FL0

36

6,0m

FL0

39

FL0

39

7,0m

FL0

37

FL0

37

7,0m

FL0

40

FL

040

5,0m 5,0m

7,0m 7,0m

6

7

8

Difference due to “after scram geometry” modeling

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Visualisation of core:

Shows evolution of core degradation

It is run in MS EXCEL

Used in verification of calculations and as a required outputfor PSA L2 scenario description and documentation.

Uses plot file output

Core visualisation

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Core visualisation

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Core visualisation

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Visualisation observations

All mass from core ejected from RPV

I some cases there are large differences in temperatureof neighbouring cells

Lower support plate can fail even when submerged in water (with TSFAIL option at 1273 K)

Prolongation of cladding without fuel can support debrisand prevent it falling onto support plate for some time

Visualisation

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Bugs and experience

CFs creep model „ghostly“ crashes when experiencing negative pressure

Just four valid numbers in RN package (40 030 kg vs. 5.108 kg)

Some test scenarios with vessel flooded experienced large RN class mass numerical error up to ~ 9%

Core crashes with not sufficient explanation, example:

RN package error ...... in VOLUM

Bugs and experience

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Nodalisation and visualisation of core

New nodalisation (along with 3loop PC/SC and ~50 volume containment) reaches addressable memory limits; not a single flow path can be added

Visualisation puts together essential core parameters into one picture

Core composition and relations between components easily seen

Conclusions