ML18054B151

Provides Justification Re Operability Determination for Continued Operation W/Piping Support Sys Stress Calculation. All Identified Deficiencies Have Been Reanalyzed & Found Acceptable or Reworked to Meet FSAR Allowables

ML18054B151
Person / Time
Site:	Palisades
Issue date:	12/01/1989
From:	Berry K CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.)
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 8912070313
Download: ML18054B151 (3)

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consumers Power Kenneth W Berry Director l'DWERINli Nuclear Licensing MICHlliAN'S l'RDliRESS General Offices: 1945 West Parnall Road, Jackson, Ml 49201 * (517) 788-1636 December 1, 1989 Nuclear Regulatory Commission Document Control Desk Washington, DC 20555 DOCKET 50-255 - LICENSE DPR PALISADES PLANT -

OPERABILITY DETERMINATION FOR CONTINUED OPERATION WITH PIPING SUPPORT SYSTEM STRESS CALCULATION DEFICIENCIES During dicussions on November 22, 1989, Consumers Power Company was requested to provide, prior to Plant startup from the current maintenance outage, a written operability determination, justifying continued operation of the Plant while reduced confidence in the accuracy of piping support system stress calculation packages exists. On November 21, 1989 Consumers Power Company submitted a summary of our plans to conduct a reverification of safety-related piping, supports, anchors and associated records. The purpose of this submittal is to provide our basis for concluding the Plant can be safely operated during completion of the Safety-Related Piping Reverification Program.

Recent NRC inspections and subsequent internal reviews have led to the conclusion that Consumers Power Company's previous efforts to review and upgrade piping support system stress capabilities were not accomplished with the thoroughness and attention to detail necessary to assure full compliance with NRC requirements. This conclusion results in questioning the validity of piping support system stress calculation packages. To address these concerns Consumers Power Company has initiated or completed the actions described below to support continued operation of the plant until these concerns are completely resolved.

First, during the current maintenance outage, we conducted a plant walkdown and a re-evaluation of a reasonable sample of pipe supports. Our re-evaluation revealed a small percentage of the supports were ioaded slightly beyond the FSAR allowable limits but well within industry code allowables, thus the actual loads do not represent a safety concern. All identified deficiencies have been reanalyzed and found acceptable or reworked to meet FSAR allowables.

In cases where rework of the as-built condition has been undertaken in response to these re-evaluations, the rework has increased pre-existing margins of safety. In no case was rework required to remedy conditions where equipment was rendered incapable of performing its safety-related design function and are concluded to be not safety significant.

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Nuclear Regulatory Commission Palisades Plant Stress Calculation Deficiencies December 1, 1989

• 2 Secondly, a total of 43 pipe hanger calculations have been redone (including walkdown and recalculation) with only one significant problem being identified.

This problem was identified in a modification package involving a main steam system pipe support and was completed about two years ago. Therefore, we conclude there has been no safety significant discoveries during the recent reanalysis efforts.

Third, as described in our Safety-Related Piping Reverification Program submittal of November 21, 1989, Consumers Power Company has initiated a program to reverify safety-related piping, supports and anchors are loaded within FSAR allowables, and to assure that record drawings accurately reflect the as-built condition. This program requires complete walkdowns, resolution of deficiencies and subsequent re~evaluation or rework of ~11 Regulatory Guide 1

1.26 Class 1 piping two and one-half inches or larger. It also requires a third party independent overview of piping stress analysis reverification work. Nonconformances identified during this program will be dispositioned through our Configuration Control Program. This dispositioning process will also require that nonconformances be reviewed against a set of interim operating criteria previously submitted and reviewed by the NRC (reference Consumers Power Company letters dated November 13 and 22, 1989) to determine if continued operation of the Plant is justified. If the interim operating criteria are not satisfied, system operability will be evaluated in accordance with Plant Technical Specifications and reportability will be determined per 10CFRSO.

In addition to the above re-evaluation and reverification efforts our Inservice Inspection Program includes an inspection of safety-related supports to verify support condition, including condition of welds. At least one cycle of inspections has been completed on each support for Class 1, 2 and 3 systems during our first 10 year inspection interval. While this effort does not specifically verify conformance of the as-built to the as-analyzed support configurations, it provides added assurance that the material condition of the supports is good.

Given that recently identified deficiencies have not represented equipment incapable of performing safety-related design functions, and a program has been initiated to reverify safety-related systems and components with provision to appropriately disposition nonconformances, it is Consumers Power Company's position that the health and safety of the public has not been placed at undue OC1189-0020-NL02

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Nuclear Regulatory Commission Palisades Plant Stress Calculation Deficiencies December 1, 1989

• 3 risk nor will be placed at undue risk by restarting the Plant at the conclusion of the current maintenance outage.

Kenneth W Berry Director, Nuclear Licensing CC Administrator, Region III, USNRC NRC Resident Inspector - Palisades OC1189-0020-NL02

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