ML20155F332

Discusses 750527 Meeting Re Discussion W/Staff That Loads Being Used by Util Not Adequately Supported by Test Data & Possibly Questionable Design Practices Being Used to Factor Load Into Design

ML20155F332
Person / Time
Site:	Grand Gulf, 05000000
Issue date:	05/29/1975
From:	Butcher E Office of Nuclear Reactor Regulation
To:	Maccary R, Tedesco R Office of Nuclear Reactor Regulation
Shared Package
ML20155E140	List: ML20155E133 ML20155E182 ML20155E227 ML20155E338 ML20155E354 ML20155E367 ML20155E405 ML20155E430 ML20155E447 ML20155E473 ML20155E503 ML20155E550 ML20155E557 ML20155E565 ML20155E578 ML20155E600 ML20155E714 ML20155E728 ML20155E753 ML20155E770 ML20155E794 ML20155E948 ML20155E967 ML20155E986 ML20155F001 ML20155F053 ML20155F176 ML20155F191 ML20155F203 ML20155F217 ML20155F228 ML20155F252 ML20155F279 ML20155F302 ML20155F332 ML20155F378 ML20155F477 ML20155F485 ML20155F516 ML20155F534 ML20155F545 ML20155F560 ML20155F589 ML20155G308
References
FOIA-88-91 NUDOCS 8806160351
Download: ML20155F332 (2)

Text

UNITED STATES O g

NUCLEAR REGULATORY COMdSSION W ASHINGToN, D. C. 20555 MAY 2 9 1975 NOTE TO: R. L. Tedesco, Assistant Director for Containment Safety, DTR R. R. Maccary, Assistant Director for Engineering, DTR THRU : R. C. DeYoung, Assistant Director for Light Water Reactors Gro RL GRAND GULF MARK III CONTAINMENT DESIGN On 5/27/75 a meeting was held with the Deputy Director of Nuclear Reacter Regulttion to discuss with menbers of the NRC staff their cenclusion that the loads being used by the Grand Gulf AE are not adequately supported by the test data ar.d that possibly questionable design practises are being used to facter these loads into the design. The purpose of this meno is to outline the options identified at this meeting to resolve these concerns for all the BWR-6/ Mark III applications and identify a specific course of action with schedule objectives ,for Grand Gulf.

The following design options will be offered to all the Mark III applicant to assure the NRC that the design loads will be sufficiently conservative to account for the uncertainties in the current test data.

1) The applicants could agree to use standard engineering practices with a conservative load profile to be specified by the containment systens branch and verified by additional testing at a latar date not necessar-ily before beginning construction; or

2) The applicants could agree to use standard engineering practices and to delay construction until the results of additional testing, to be spec-ified by the containment systems branch, is available and has been re-viewed by the NRC staff (CSB estinates that the testing and data evalua-tion could take as long as 3-4 conths); or

3) The applicants could agree to reloc, ate structures and mechanical and electrical equipment below a certain elevation (approx. 20 feet above the suppression pool) to be specified by the Containment Systems Branch.

Ioads on structures and equipment that cannot be relocated (i.e. vertical walls) must be justified by either option 1) or 2) above.

The adoption of one of these options would be acceptable for issuance of con-struction permits and PDA's for applications using the GE Mark III contain-ment concept (tbis group includes the GESSAR-238, Perry, Allens Creek, and River Bend plants, for which the ACRS has co=pleted its reviews; and Douglas Point, Barton, Montague, Skrigit, Clinton, and Hartsville, for which the staff SERs have yet to be issued).

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_2 lgy 2 3 975 The Grand Gulf case is the cost pressing problen because the CP has been issued and the applicants will begin pouring concrete for the contain. tent base mat on 6/26/75. It was decided that construction on the containment should not proceed until the NRC is satisfied that the cargins in the structural capability are adequate to account for the uncertainties in tde current data or until better test data is available. If the Grand Gulf applicants agree to voluntarily adopt one of the above options, no' enforce-ment action would be necessary to satisfy NRC staff concerns. If they do not agree to one of the options the NRC will have to identify a specific health and safety concern upon which to base a Show Cause Order if we requira resolutien of this concern prior to pouring concrete. The following is the specific course of action and schedule objectives agreed upon for Grand Gulf:

CSB - Specify by 5/30/75 additional tests required to justify design loads.

- Specify by 5/29/75, a conservative load profile that =ust be used if the applicants do not wait for additional test data.

- Specify restr.ctions on elevation above the suppression pool for structures and cechanical equipment, by 5/29/75.

SEB - Prepare a question list by 5/30/75 identifying discussion topics for a 6/4/74 ceeting with the applicants to attempt to identify the margins in the existing design.

- Determine what targins if any exist in the contain=ent design, by 6/5/75.

RL - Inform the applicant by 5/30/75, of the actions the NPC intends to

.' take based on their response to the options outlined above. Provide tha question list prepared by SEB and request the appliccnts to be prepared

. to discuss these questions and their decision to adopt one of the NRC options at a meeting on 6/4/75.

- Make reco=:endation to regulatory management on whetber or not to issue a Shou Cause Order based on the results of the 6/4/75 ceeting with the applicant and SEB's abilit'/ to determine the existing design targins.

The reco=endation should be prepared by 6/6/75.

c Q Ldf Eduard J. Butcher, Project Engineer Light Water Reactors Branch 1-2 Division of Reactor Licensing cc:

VAMoore Shou BBo rdenick GClainis JMCutchin FSchroeder RLCudlin RPowell JKudrick JStolz RS Boyd RMaccary WRButler BRusche LShao LSlegers AGiambusso RCDeYoung ISibweil ECCase EJButcher DCrutentield W0lmstead