ML20198F946
| ML20198F946 | |
| Person / Time | |
|---|---|
| Site: | Washington Public Power Supply System |
| Issue date: | 10/29/1975 |
| From: | Cox T Office of Nuclear Reactor Regulation |
| To: | Moore V Office of Nuclear Reactor Regulation |
| References | |
| CON-WNP-1099 NUDOCS 8605290151 | |
| Download: ML20198F946 (2) | |
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Docket File (
LWR 2-3 File MWilliams TCox EGoulbourne OCT. 2 91975 ASchwencer Docket flos. 50-460 and 50-513 c4$. A. floore, Assistant Director for Light Water Reactors, Group 2. DRL
- 6. d ;f THRU: A. Schwencer, Chief, Light Water Reactors Branch 2-3, DRL f
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WilP-1,4 HEARIllG TESTIM 0 fly Otl REACTOR PRESSURE VESSEL SUPPORT ISSUE I believe that the testimony filed in this case on October 15, 1975, regarding reactor pressure vessel supports, should be supplemented to include some material recognizing and addressing the specific issue of containment subcompartment differential pressure analyses (SPA).
The rad safety hearing is scheduled for flovember 11, 1975.
Applicant, in a recent submittal to the staff (Attachment 1) concerning the RPV support issue, presented a revised design (they have added guard pipes on hot and cold legs) and analysis of the subcompartment pressure differentials. Their new analysis uses essentially the same computational techniques as the earlier design analysis which we reported acceptable in Supplement ilo. 1, June 2, 1975. But for the revised design, the Applicant claims much reduced reactor cavity
, pressures from that approved by staff in June 1975.
I feel the Board will inquire into staff review status on this issue quite apart from
~
the fact that the SPA pressure-time histories are only one of several inputs to the total loads on RPV supports.
The staff testimony of October 15,1975 (Attachnent 2, see page 7, last paragraph) states that we are confident that if Applicant uses certain known analytical techniques like WHAM, Applicant can, in our judgement, adequately predict the RPV loads resulting from forces applied by the i
"themal and hydraulic response of the core to the postulated rupture".
The reference to the UHAM code at this point in the testimony applies only to the calculation of " internal pressure diff arentials" rather l
l than to subcompartment pressure differentials or to jet impingenent l
loads. We must also provide testimony to our conviction that Applicant I
can predict pressure-time histories within containment subconcartments, i
either with the engineering criteria and methods he proposes to use or those which we require him to use. We must similarly conclude that Applicant can adequately design for jet impingement loads on affected structures or components.
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8605290151 751029 PDR ADOCK 05000460 A
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OCT. 2 91975 6
s V. A. Moore A. Schwencer 2-I suggest that the ASLB will not be satisfied with a verbal statement by the LPf1 at the hearing that we are considering the SPA and jet i
impingement loads as part of the overall " generic" issue and expect a satisfactory resolution. We must provide some bases for the con-clusion, and then draw the conclusion, pursuant to 10 CFR 50.35(a),
that Applicant has described the proposed design, including but not limited to the principal engineering criteria, and that such further technical and design information as may be required to complete the safety analysis can be left for later consideration, and that this infonnation will be supplied by Applicant and reviewed by staff within the time required to ha included in the Final Safety Analysis Report.
I've included a suggested supplement (Attachment 3) to the October 15, 1975 testimony, and respectfully request your early consideration of this material.
c,ijrM s w dby T.Cox Thomas Cox, Project Manager Light Water Reactors Branch 2-3 Division of Reactor Licensing Attachments:
1.
Ltr fm WPPSS to R. S. Boyd dtd 9/3/75 2.
Supplemental Testimony by V'. iloonan -
3.
Proposed Ifodification to Testimony by V. tioonan RL: LWR 2-3 RL: LWR 2-3 o,,,..
TCox:pgM ASc ncer__
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Forma MC 318 (Rev. 9 53) MCM 0240
- u. s. oovaRNMEMt PRINTING OPPICEa 9974 534-16e