ML20012C587

Forwards SER Re Facility Piping Support Calculations for safety-related Piping,Per 890320-23 & 0724-29 Audits.No Significant Safety Concern for Existing safety-related Piping Sys Noted

ML20012C587
Person / Time
Site:	Grand Gulf
Issue date:	03/16/1990
From:	Kintner L Office of Nuclear Reactor Regulation
To:	Cottle W SYSTEM ENERGY RESOURCES, INC.
Shared Package
ML20012C588	List: ML20012C587 ML20012C589
References
TAC-71863, NUDOCS 9003220237
Download: ML20012C587 (4)

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March 16, 1990 Docket No. 50-416 Mr. W. -- T. Cottle Vice Presid2nt, Nuclear Operations System Energy Resources, Inc.

Post Office Box 469-Port Gibson, Mississippi 39150

SUBJECT:

CRAND GULF HUCLEAR~ STATION,) UNIT 1 - 111DIT OF PIPING SUPPOR CALCULATIONS (TAC NO. 71863 On March 20-23,1989,)an NRC review team performed an audit at the Grand Gulf Nuclear Station'(GGNS, Unit 1 of pipe support calculations for safety-related piping. As a result, a follow-up audit was performed during July 24-29, 1989.

The IRC review team during each audit consisted of a Mechanical Engineering Branch staff menber (different in each audit) and a consultant f mm EAS, Inc.

L A number of technical concerns were ~ identified and discussed with System Energy Resources, Inc. (the. licensee).. Enclosed is the NRC staff's Safety Evaluation

. Report of these concerns.

Based upon the staff evaluation of licensee's design practices and responses, we conclude that there is no significant safety n

L concern for existing safety-related piping systems. However, the licensee has undertaken a snubber reduction program, based on the application of the damping values in ASME Section III Code Case N-411. These damping values are higher

.than those under which the plant was licensed, so that for the same seismic

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excitation a~ smaller number of snubbers is required to achieve the same piping.

stress-levels as those obtained with the lower danping values. -It is, therefore, very likely that'the loads on the remaining supports, both rigid restraints and snubbers,' will increase while the redundanqy of the' system will decmase.

Thus, the' reliability of the remaining supports should be higher than that in the-original design. To provide this assurance of reliability, the licensee should consider the effects of the technical issues raised in the audits.

The design or reevaluation of all piping supports in the. snubber reduction program and in pipirg system additions or modifications should include the effects identified in the enclosed safety Evaluation Report.

The licensee has alrea@ revised the GGNS Pipe Support Design Specification to include most of these effects for application to new supports.

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i This letter coupletes our review of this natter for GGNS Unit 1.

You are requested to advise us by letter of your disposition of the rennining effects identified in the enclosed Safety Evaluation Report with respect to

incorporating them into the GGNS Pipe Support Design Specification.

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I addition, you are requested to describe design calculations made for cable L

tray supports in the. turbine building.

l The reporting and/or recordleeping requirenents contained in this letter affect fewer than ten respondents; therefore, OMB clearance is not required under P.L.96-511.

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Orignal Signed by:

Lester L. Kintner, Senior Project Manager l.

Project Directorate II-1.

Division of Reactor Projects. I/II Office of Nuclear Reactor Regulation

Enclosure:

As stated cc w/ enclosure:

See next page

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3. Varga 14-E-4 G. Lainas 14-H-3 E. Adensam 14-B-20 P. Anderson 14-B-20 L. Kintner 14-B-20 l

OGC (Por inform. Only) 15-D-18 E. Jordan MNBB-3302

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Mr. W. T. Cottle.

Grand Gulf IOclear Station (GGNS)

System Energy Resources, Inc.

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Mr. T. fl. Cloninger Mr. C. R. Hutchinson Vice President, Nuclear Engineering GGNS General Manager l

& Support Systera Energy Resources, Inc.

System Energy Resources, Inc.

P. O. Box 756 P. O. Box 31995 Port Gibson, Mississippi 39150 Jackson, Mississippi 39286 Robert B. McGehee, Esquire The Honorable William J. Guste, Jr.

Wise Carter, Child, and Attorney General Ca raway Department of Justice P. O. Box 651 State of Louisiana Jackson, Mississippi 39205 P. O. Box 94005 Baton Rouge, LA 70804-9005 Nicholas S. Reynolds, Esquire Bishop, Cook, Purcell Alton B. Cobb, M.D.

and Reynolds State Health Officer 1400 L Street, N.W.

12th Floor State Board of Health Washington, D.C.

20005-3502 P. O. Box 1700 Mr. Ralph T. Lally Manager of Quality Assurance Entergy Services, Inc.

Office of the Governor P. O. Box 31995 State of Mississippi Jackson, Mississippi 39286 Jackson, Mississippi 39201 Mr. Jack McMillan, Director

Pmsident, Division of Solid Waste Management Claiborne County Board cf Supervisors Hississippi Department of flatural Port Gibson, Mississippi 39150 Resource s P. O. Box 10385 Jackson, Mississippi 39209 Regional Administ9 tor, Region II U.S. Esclear Regulatory Consission Mr. John G. Cesare 101 Mcrietta St., Suite 2900 Director, fluclear Licensing Atlanta, Georgia 30323 System Energy Resources, Inc.

P. O. Box 469 Port Gibson, Mississippi 39150 Mi ke Moore, Attorney General Frank Spencer, Assist. Attorney General fir. C. B. Hogg, Project Manager State of Mississippi Bechtel Power Corporation Post Office Box 22947 P. O. Bcx 2166 Jackson, Mississippi 39225 Houston, Texas 77252-2166 Mr. H. O. Christensen Senior Resident Inspector U.S. Nuclear Regulatory Counission Route 2, Box 399 Port Gibson, Nississippi 39150

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