ML20235D058

Discusses BWR Pressure Suppression Designs Based on Peak Pressure Prediction on Computer Codes Developed from Tests Performed at Humboldt & Bodega Bay

ML20235D058
Person / Time
Site:	Humboldt Bay, 05000000, Bodega Bay
Issue date:	04/30/1963
From:	Rosen M US ATOMIC ENERGY COMMISSION (AEC)
To:	Deyoung R US ATOMIC ENERGY COMMISSION (AEC)
Shared Package
ML20234A767	List: IA-85-665, Discusses Seismic Design of Nuclear Power Plants,Including Const of Nuclear Plants in Seismically Active Zones ML20234A761 ML20234A769 ML20234A792 ML20234A798 ML20234A803 ML20234A812 ML20234A816 ML20234A827 ML20234A830 ML20234A838 ML20234A841 ML20234A844 ML20234A847 ML20234A851 ML20234A855 ML20234A858 ML20234A861 ML20234A864 ML20234A868 ML20234A871 ML20234A874 ML20234A893 ML20234A896 ML20234A900 ML20234A911 ML20234A922 ML20234A929 ML20234A932 ML20234A937 ML20234A944 ML20234A956 ML20234A965 ML20234A968 ML20234A976 ML20234A984 ML20234A993 ML20234A996 ML20234A999 ML20234B005 ML20234B008 ML20234B023 ML20234B032 ML20234B035 ML20234B040 ML20234B062 ML20234B066 ML20234B076 ML20234B084 ML20234B098 ... further results
References
FOIA-85-665 NUDOCS 8709250100
Download: ML20235D058 (2)

Text

..

I

"' )

a

_ , ( \

~ ,

f' TD~r)) \

SD ~ o? C f APR ') a org I

,)

I i R. C. DeYoung, Deputy Assistant Director for Reactor Technology, DRL HUMBOLDT BAY AND BODEGA BAY USE OF TESTS TO SUBSTANTIATE PRESENT BWR DESIGE Present BUR pressure suppression designs base their prediction of peak pressure on computer codes developed from tests performed at Humboldt Bay, and Bodega Bay. These codes incorporate conservative assumptions (c'.g. , no stermi condensation on the drywell valls and structures,100%

liquid cargover through the vents, use of Hoody's model for blowdown mass and energy rates) so that the calculated drywell and wetwell pres-sure for the test conditions are always higher than those measured. As discussed below, since many of the design features of the tests have been carried over into present BWR designs, the use of these computer codes should result in conservative predictions of peak vetwell and drywell pressures for these designs. In addition, a substantial margin between the calculated peak pressure and the design pressure is incor-porated into all designs.

Considering available experimental methods, the Bodega and Humboldt Bay tests were poorly conducted. For example, blowdwn rates were not measured, and in the Bodega Bay tests the liquid carryover wcs not measured. In addition, the degree to which the analytical model agrees with the test results varies from test to test. Consequently, the effect of any varia-tions in design features can only be partially understood.

Design features in the tents which are similar to those utilized in actual BWR designs include maintaining the same vent resistance factor, the same downcomer submergence, and the same break to irent area ratio as '

in Bodega tests B-17 and B-30. The amount of water in the vetwell in present designs is such that the water temperature vill not exceed 170*F during blowdown. This temperature is based upon a minor extrapolation of the Hu:nboldt and Bodega test results where complete condensation was observed at 163*F (condensation in the pool water may be possible up to

• the saturation temperature of 240'F).

The testa did not establish whether there is a minimum required spacing between downcomer pipes, what spacing is required between the bottom of downcomer pipes and the bottom of the torus to prevent severe blowdown c impacts, the maximum pool water temperature that will permit condensation, f.

and the influence cf changes in vent system designs on the peak vet and h 4 .

drywell pressures.

s il 8709250100 851217 PDR FOIA '

FIRESTOSS-665 PDR -

_ - - - - - - - - - - ~ ~ ~ - ~ ~ ~

(

(

f-.- '

"r l R. D. DeYoung

! c api; 3 9 633 b'

of the features of the Bodoga and Humboldt Bay tests, p As new designs are presented that differ from the Bod .

..,' (such and the LILCO Shoreham Plant), additional tests may be warranted l Applicants with new designs should either run additional tests or show that design changes are not significant or result in greater margin .

i The DRL Technical Assistance Group at Phillips is developing the CONTEMPT P code which can be used to calculato BWR containment pressure transients. -

This codo has satisfactorily predicted the available Humboldt and Bodega test results and is scheduled for cot:pletion this June. When completed, DRL will have an independent ::ethod of verifying the adequacy of DWR designs.

The Phillips' group believes the Shoreham containment design when compared to prescat designs is similar in regards to the important . ' ,

j pressure cc,de. suppression parameters and can be analyzed using the CONTEMPT-PS

?  !

'* Original signed by M. Itosen i

RT-385A Morris Rosen, Chief DRL:NTS:HS Nuclear Technology Branch Division of Reactor Licensing l

Distribution:

S uppl<$~ -G DRL Reading

} ADRT Reading NTB Reading 3 h"c: a S. Levine M. Rosen

11. Specter [.

1 h

\

omcg, . DR..L :NT. S .

. .DR. .L. ; N TB. .... . _

sumuc > llSpc c cer ;Ibw....L ..MRos en., ,,,,,,.

onc 5. , ,

Furata AFC.38f4 (Iter. p.33). 4/ 3. 0. ./. 6 9...=.m.

4. ./.,'3.:./. .l

6. 9....... .. . . , , , , , , ,

..i...._....

?E '

_ _ _ _ . - - - - -