ML17083B305

Propounds That Low Power Operation Acceptable & Will Not Compromise Required Corrective Actions.Requirement Re Hot Shimming for Closely Spaced Restraints on Large Bore Piping Merits Further Review

ML17083B305
Person / Time
Site:	Diablo Canyon
Issue date:	04/09/1984
From:	Ebersole J Advisory Committee on Reactor Safeguards
To:	Palladino N NRC COMMISSION (OCM)
References
ACRS-R-1082, NUDOCS 8404100506
Download: ML17083B305 (6)

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~O 4tt44 UNITED STATES NUCLEAR REGULATORY COMMISSlON ADVISORYCOMMITTEEON REACTOR SAFEGUARDS WASHINGTON, D. C. 20555 Enclosure 4

April 9, 1984 Honorable Nunzio J. Palladfno Chairman U.

S. Nuclear Regulatory Commission Washington, D.C.

20555

SUBJECT:

ACRS REPORT ON DESIGN CONTROL MEASURES AT THE DIABLO CANYON NUCLEAR POWER PLANT During its 288th meeting, April 5-7, 1984, the Advisory Committee on Reactor Safeguards reviewed the technical issues arising from the Diablo Canyon Licensee's design control measures for small and large bore piping, as requested fn your letter dated April 4, 1984.

During this review we had the benefit of presentations by members of the NRC Staff, including NRC Inspector Isa Yfn, by representatives of the Pacific Gas 5 Electric Company (Licensee) and of the Independent Design Veriffcation Program organfza-

tions, and by Mr. Charles

Stokes, a member of the public.

We also had the benefit of the documents listed.

We were informed that there fs no longer disagreement between the NRC Staff and Mr. Yin.

They now agree on a series of actions that must be completed by the Licensee and by the NRC Staff to resolve certain questions, and agree that these should be completed before operation at full power.

They agree also that operation and low power testing at levels up to five percent of full power can be permitted without undue risk to the health and safety of the public.

We agree that it is acceptable to permit low power operation at this time.

We believe that such operation will not compromise corrective actions that may be requi red.

We believe that the several actions proposed by the NRC Staff for comple-tion before operation above five percent power will provide a

suitable basis for considering operation at full power.

The Licensee has agreed to the actions proposed by the NRC Staff before operation above five percent power with one exception.

This exception relates to the need for or desirabil ity of "hot shimming" for closely spaced restraints on large. bore piping.

We believe that thfs requirement deserves further technical review and discussion between the NRC Staff hand the Licensee.

<0

Honorable Nunzio J. Palladino Apri1 9, 1984 We understand that allegations such as those made by Mr. Stokes will be investigated and appropriately considered by the NRC Staff.

Additional comments by ACRS members Robert

Axtmann, Jesse

Ebersole, and David Okrent are presented below.

Sincerely, Jesse C. Ebersole Chairman Additional Comments b

ACRS members Robert Axtmann, Jesse

Ebersole, and David Okrent We agree with the ACRS conclusion on operation at five percent power.

In view of the limited time available for review of this matter, the bulk of documentation, and the lateness of some documents in reaching us, our review was of necessity limited in its depth.

Prior to an ascent in power above five percent, the NRC Staff should pre-pare a document discussing in considerable detail how the various relevant issues raised by its inspectors and others have been handled.

The NRC Staff should also perform a careful examination of a

selected sample of actual construction details to help assure that the appropriate quality has been accomplished.

We believe the ACRS should be given an opportunity to review these results prior to the achievement of full power at the Diablo Canyon Nuclear Power Plant.

References:

l.

U.

S. Nuclear Regulatory Commission Transcript of the March 26 and 27, 1984 meeting in the matter of Discussion/Possible Vote on Diablo Canyon Criticality and Low Power Operation, Pages68-102, 233-256,

263, 279, and 281-287 2.

U.

S; Nuclear Regulatory Commission Transcript of the March 28, 1984 meeting between Staff, Applicant and Intervenor on Diablo Canyon, Pages 1-124 3.

U.

S. Nuclear Regulatory Commission Transcript of the meeting on April 2, 1984 in the matter of Pacific Gas 5 Electric Company on Diablo Canyon, Pages 1-272 4.

I. T. Yin, "Diablo Canyon 1, Summary of Findings Resulting From ollow-up of Allegations and NRC Independent Overview," Draft dated Mar'ch 29, 1984

Honorable Nunzio J. Palladino 3

Apri1 9, 1984 5.

6.

70 8.

9.

10.

11.

12.

I. T. Yin, "Diablo Canyon 1, Draft Investigation/Inspection Report,"

Rev. 3, dated March 29, 1984 Memorandum, with enclosure, from Darrell G. Eisenhut, Director, Division of Licensing, U.

S. Nuclear Regulatory Commission, to Chairman Palladino and Commissioners, U. S. Nuclear Regulatory Commission,

Subject:

Diablo Canyon - Allegations Concerning Small Bore Piping and Supports (Board Notification No.83-171), dated October 27, 1983 U.

S. Nuclear Regulatory Commission, "Safety Evaluation Report Related to the Operation of Diablo Canyon Nuclear Power Plant, Units 1

and 2,"

USNRC Report NUREG-0675, Supplement No. 22, dated March 1984 Exhibit A, "Affidavit of Charles Stokes,"

dated November 1983 to Motion to Atomic Safety and Licensing Appeal Board, "Joint Inter-venor s'otion to Augment or, in the Alternative, to Reopen the Re-cord" fn the Matter of Pacific Gas and Electric Company (Diablo Canyon Nuclear Power Plant, Units 1

and 2), dated February 14, 1984 Pacific Gas and Electric Company's Answer in Opposition to Joint Intervenors'otion to Augment or, in the Alternative, to Reopen the Record in the Matter of Pacific Gas and Electric Company (Diablo Canyon Nuclear Power Plant, Units 1

and 2) without attach-

ments, dated March 6, 1984 Letter No. DCL-84-131, from J. 0. Schuyler, Pacific Gas and Electric Company to Mr. Harold R. Denton, Director, Office of Nuclear Reactor Regulation, U.

S. Nuclear Regulatory Comnission,

Subject:

Response

to Board Notification 84-071 on Diablo Canyon Unit 1, dated April 4, 1984 Summary of Remarks of Charles Stokes Before the Advisory Committee on Reactor Safeguards Concerning the Diablo Canyon Nuclear Power Plant, dated April 6, 1984 Letter No. P105-6 from Robert L. Cloud, Robert L. Cloud Associates, Inc., to Mr. G.

A. Maneatis, Pacific Gas and Electric Company, Mr. H.

R. Denton, U.

S. Nuclear Regulatory Commission, and Mr. J.

B. Martin, Region V, U.

S. Nuclear Regulatory Commission, regarding allegations at Diablo Canyon, dated February 3, 1984