ERMSAR 2012, Cologne, March 21 – 23, 2012 Hydrogen Stratification in Experimental Facilities and...

ERMSAR 2012, Cologne, March 21 – 23, 2012

Hydrogen Stratification in Experimental Facilities and PWR Containments – Results and Conclusions of

Selected COCOSYS Simulations

S. Schwarz, S. Band, M. Sonnenkalb

GRS Germany


– During a severe accident hydrogen (H2) could be generated in the reactor coolant system (RCS)

– In case of a release at an elevated position in the containment -> atmospheric stratification -> high H2 concentrations above and low H2 concentrations below the release position

– Stratification can be dissolved by different processes

– H2 distribution in containment -> flammability

– Experiments, COCOSYS validated: THAI, PANDA, HDR E11.2

– PWR application by COCOSYS

2


HDR containment

COCOSYS nodalisation 143 nodes inclusive annular compartments and gap

E11.2 experiment

0 – 12.5 h: upper steam injection

12.32 – 12.87 h: H2/He injection

12.88 – 16 h: lower steam injection

16.25 – 20 h: spraying upper hemisphere

after 20 h: natural cooldown, venting

3

D48P

R1902L R1902R R1903

R1903P

R1905

R180524

H2/HeR180523

R1804L R1804R

R1708oL

R1708uL

R1708oR

R1708uR

RMon_20

RMon_17

R22_14

R22_12

R20_14

R20_12

R19_12

R16_7

R14_7

R15_7

R13_3

R13_1

R12_3

R12_1R8_1

R9_3

R9_1

R4 R2 R2

R1

R1 R1

D43M

D41M

D393M

D378M

D363M

D348M

D333M

D317M

D45M

D317W

D333W

D348W

D363W

D378W

D393W

D41W

D43W

D45W

D48M

D45P

D43P

D41P

D393P

D378P

D363P

D348P

D333P

D317P

50 m

31 m

-10 m

steam

steam

steelshell

RPV

90?spiral stair case side

270?stair case side

D317T

D333T


(cocosys)HDR E11.2 Exp.,1-id

0 5 10 15 20 25

Zeit (h)

0

5

10

15

20

H2+

He c

once

ntr

atio

n (

%)

CG435 40.5m 295° 2.4mC1_HE+H2_GAS_D41MCG1434_34mC1_HE+H2_GAS_D348TCG432 30.6m-270°-ÜÖC1_HE+H2_GAS_R1902RR1_CG1033_-4.5mC1_HE+H2_GAS_R1phases

4

D48P

R1902L R1902R R1903

R1903P

R1905

R180524

H2/HeR180523

R1804L R1804R

R1708oL

R1708uL

R1708oR

R1708uR

RMon_20

RMon_17

R22_14

R22_12

R20_14

R20_12

R19_12

R16_7

R14_7

R15_7

R13_3

R13_1

R12_3

R12_1R8_1

R9_3

R9_1

R4 R2 R2

R1

R1 R1

D43M

D41M

D393M

D378M

D363M

D348M

D333M

D317M

D45M

D317W

D333W

D348W

D363W

D378W

D393W

D41W

D43W

D45W

D48M

D45P

D43P

D41P

D393P

D378P

D363P

D348P

D333P

D317P

50 m

31 m

-10 m

steam

steam

steelshell

RPV


270?stair case side

D317T

D333T

H2/He concentrations experiment, COCOSYSinjection phase

• Hydrogen stratification• Light gas cloud (H2/He,

air steam) in upper region

ERMSAR 2012, Cologne, March 21 – 23, 2012 5


0 5 10 15 20 25

Zeit (h)

0

5

10

15

20

H2+

He c

once

ntr

atio

n (

%)


D48P

R1902L R1902R R1903

R1903P

R1905

R180524

H2/HeR180523

R1804L R1804R

R1708oL

R1708uL

R1708oR

R1708uR

RMon_20

RMon_17

R22_14

R22_12

R20_14

R20_12

R19_12

R16_7

R14_7

R15_7

R13_3

R13_1

R12_3

R12_1R8_1

R9_3

R9_1

R4 R2 R2

R1

R1 R1

D43M

D41M

D393M

D378M

D363M

D348M

D333M

D317M

D45M

D317W

D333W

D348W

D363W

D378W

D393W

D41W

D43W

D45W

D48M

D45P

D43P

D41P

D393P

D378P

D363P

D348P

D333P

D317P

50 m

31 m

-10 m

steam

steam

steelshell

RPV


270?stair case side

D317T

D333T

H2/He concentrations experiment and COCOSYSduring lower steam injectionand 1st part of spraying

- Concentrations at different elevations

- Same elevation -> same color for COCOSYS and experiment

Hydrogen stratification in domeContraction of light gas cloudSimulated by COCOSYSContraction accelerated during spraying



0 5 10 15 20 25

Zeit (h)

0

5

10

15

20

H2+

He c

once

ntr

atio

n (

%)


6

D48P

R1902L R1902R R1903

R1903P

R1905

R180524

H2/HeR180523

R1804L R1804R

R1708oL

R1708uL

R1708oR

R1708uR

RMon_20

RMon_17

R22_14

R22_12

R20_14

R20_12

R19_12

R16_7

R14_7

R15_7

R13_3

R13_1

R12_3

R12_1R8_1

R9_3

R9_1

R4 R2 R2

R1

R1 R1

D43M

D41M

D393M

D378M

D363M

D348M

D333M

D317M

D45M

D317W

D333W

D348W

D363W

D378W

D393W

D41W

D43W

D45W

D48M

D45P

D43P

D41P

D393P

D378P

D363P

D348P

D333P

D317P

50 m

31 m

-10 m

steam

steam

steelshell

RPV


270?stair case side

D317T

D333T

H2/He concentrations experiment and COCOSYS2nd part of spraying and remaining test

Mixing of atmospherePartial dilution of stratification by outside sprayingSimulated by COCOSYS


steel shell

annularcompartmentsannular

compartments

equipmentcompartments

PWR containment

steel shell diameter 56 m

equipment compartments separated by doors and rupture elements from rest of containment

Passive Autocatalytic Recombiner (PAR) concept with ~60 devices

COCOSYS nodalisation: 281 zones inclusive annular compartments and gap


Core melt scenario “ND*” Loss of SG-feedNo ECCS availableRelease from RCS/Prz.at an elevated position

Main events: 1.4 h start steam

release from RCS/Prz. 2.2 h start H2 release

from RCS/Prz. 6.4 h start release by

MCCI in cavity 17.1 h start melt -

sump water contact


compartments

releasefrom RCS

releaseby MCCI

steel shell



reference containment ND* core melt scenario

0 2 4 6 8 10 12 14 16 18 20

time (h)

0

2

4

6

8

10

H2

co

nce

ntr

atio

n (

Vo

l%)

C1_H2_GAS_D110C1_H2_GAS_D23AC1_H2_GAS_R67AC1_H2_GAS_R66AC1_H2_GAS_R65AC1_H2_GAS_R43AC1_H2_GAS_RSUAphases


compartments

releasefrom RCS

releaseby MCCI

steel shell


Hydrogen concentrations dome and equipment compartments

Hydrogen generation in equipment compartments, difference to E11.2

Mixing of dome, combination of heat sinks and sources, difference to E11.2

Hydrogen stratification in equipment compartments


reference containment ND* core melt scenario

0 2 4 6 8 10 12 14 16 18 20

time (h)

0

2

4

6

8

10

H2

con

cen

tratio

n (

Vo

l%)

C1_H2_GAS_D110C1_H2_GAS_D23AC1_H2_GAS_R74AC1_H2_GAS_R73AC1_H2_GAS_R72AC1_H2_GAS_R52Aphases


compartments

releasefrom RCS

releaseby MCCI

steel shell

equipmentcompartments Hydrogen concentrations

dome and compartments behind missile protection

Hydrogen stratification behind missile protection


Summary, conclusions– COCOSYS was validated successfully against several

stratification experiments; here the example HDR E11.2 was shown..

– A hydrogen release at an elevated position can create an atmospheric stratification – high hydrogen concentrations at and above the release position an low concentrations below.

– Same for experiments (f.e. HDR E11.2) and the PWR calculation.

– PWR in addition: stratification behind missile protection.

– The dilution of the stratification as observed in E11.2 cannot be compared with the PWR calculation because the boundary conditions differed strongly between both cases.

ERMSAR 2012, Cologne, March 21 – 23, 2012 Hydrogen Stratification in Experimental Facilities and...

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Transcript of ERMSAR 2012, Cologne, March 21 – 23, 2012 Hydrogen Stratification in Experimental Facilities and...