ML20214G535

Summary of 741018 Meeting W/Util & B&R Re Sacrificial Shield Pressure Response post-CP Review.List of Attendees Encl

ML20214G535
Person / Time
Site:	Columbia
Issue date:	11/01/1974
From:	Orndoff J US ATOMIC ENERGY COMMISSION (AEC)
To:	US ATOMIC ENERGY COMMISSION (AEC)
References
CON-WNP-0054, CON-WNP-54 NUDOCS 8605220259
Download: ML20214G535 (4)

Text

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im 1 1974 50-397. % %.

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AFFLICANT:

Washington Public Power Supply System (WPPSS)

FACILITf:

Washington Nuclear Project No. 2 SUDGIARY OF MEFfING BELD TO DISCUSS SACRIFICIAL SHIELD FRRSSURE RESPONSE Representatives of VFPSS met with the Regulatory staff on October 18, 1974 to discuss our continuing post-CP review of the sacrificial shield design for their BWR/5, Mark II system. A list of attendees is given in Enclosure 1.

I WPPSS summarized their present situation with regard to the construction schedule. The sacrificial shield is msw a critical path item because of delays incurred in resolving the concerns with subcompartment pressure response and structural design. The analyses currently in use are more sophisticated than those origina13y used and the answers are coming out differently. Concrete for the battaa section of the sacrificial shield pedestal is being poured and construction will be stalled soon until the shield design can be finalized. A minimum of three months of delay appears to be certain. WPPSS reported on the results of their analyses.

The following susmery lists the significant features of the discussions.

1.

WPPSS presented the results of their sensitivity studies of the shield compartment pressure response. Pressures are very sensitive to model assumptions. Model variations are the result of assumptions used for (a) flow splitting at the pipe break, (b) flow splitting about the free-standing insulation between the shield and the pressure vessel, and (c) venting and vent plugging at the penetrations.

2.

The staff stated that WPPSS would have to came up with a realistic i

model that they could support. Criteria for plugging or not l

plugging of the vents are important. Qualitative and difficult j

judgments are hard to justify and should be avoided.

3.

WPPSS will submit their subcompartment analyses, providing information required by the staff to aske an independent check. WPPSS will provide a model making use of realistic assumptions based on what they feel are the actual conditions.

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Distribution:

Docket File G.' Lear AEC PDR S. Pewlicki local PDR R. S. Boyd L Reading G. 141nas V. A. Moore R. Cudlin R. C. DeYoung J. Kudrick D. Skovholt A. Gluckmann D. Muller l

W. Besaw R. Denise J. Orndoff W. Butler J. Stolz R. Clark R. Ireland D. Vassallo K. Kniel K. Coller A. Schwencer F. Collins R. Purple D. Ziemann G. Rnighton G. Dicker B. Youngblood W. Regan S. Varga R. W. Klecker P. Schroeder H. Denton R. Tedesco R. Maccary V. Stello B. Grimes M. Spangler R. Ballard Jacob Kastner W. Gann111 V. Benaroya R. Vollmer Q. Long G. Lainas J. Rnight S. Pawlicki L. Shao T. Ippolito R. Houston T. Novak D. Ross EP Project Manager Attorney, OCC R0 (3)

M. Maigret R. Fraley (16)

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ATOMIC ENERGY COMMISSION

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NOV 1 gy4 DOCKET NO:

50-397 APPLICANT:

Washington Public Power Supply System (WPPSS)

FACILITY :

Washington Nuclear Project No. 2 (formerly Hanford-2)

SUMMARY

OF MEETING HELD TO DISCUSS SACRIFICIAL SHIELD PRESSURE RESPOSSE Represeatatives of WPPSS met with the Regulatory staff on October 18, 1974 to discuss our continuing post-CP review of the sacrificial shield design for their BWR/5, Mark II system. A list of attendees is given in Enclosure 1.

WPPSS summarized their present situation with regard to the construction schedule. The sacrificial shield is now a critical path item because of delays incurred in resolving the concerns with subcompartment pressure response and structural design. The analyses currently in use are core sophisticated than those originally used and the answers are coming out differently. Concrete for the bottom section of the sacrificial shield pedestal is being poured and construction will be stalled soon until the shield design can be finalized. A minimum of three months of delay appears to be certain. WPPSS reported on the results of their analyses.

The following summary lists the significant features of the discussions.

1.

WPPSS presented the results of their sensitivity studies of the shield compartment pressure response. Pressures are very sensitive to model assumptions. Model variations are the result of assumptions used for (a) flow splitting at the pipe break, (b) flow splitting about the free-standing insulation between the shield and the pressure vessel, and (c) venting and vent plugging at the penetrations.

2.

The staff stated that WPPSS would have to come up with a realistic model that they could support. Criteria for plugging or not plugging of the vents are important. Qualitative and difficult judgments are hard to justify and should be avoided.

3.

WPPSS will submit their subcompartment analyses, providing information required by the staff to make an independent check. WPPSS will provido a model making use of realistic assumptions based on what they feel are the actual conditions.

ff l.4O John Orndoff

//

Light Water Reactors Projects Branch 1-2 Directorate of Licensing

ENCLOSURE 1 LIST OF ATTENDEES

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WASHINGTON PUBLIC POWER SUPPLY SYSTEM WASHINGTON NUCLEAR PROJECT No. 2 t

OCTOBER 18, 1974 AEC WPPSS Burns & Roe R. Boyd C. Fies D. Baker S. Pawlicki C. Gelhaus F. Patti G. Lainas J. Woolsey T. Hsu R. Cudlin A. Stivers M. Kroncish J. Kudrick J. Verderber A. Gluckmann W. Besaw J. Orndoff

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