ML20042A653
| ML20042A653 | |
| Person / Time | |
|---|---|
| Site: | Washington Public Power Supply System, 05000464 |
| Issue date: | 03/05/1982 |
| From: | Mazur D WASHINGTON PUBLIC POWER SUPPLY SYSTEM |
| To: | Faulkenberry R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| References | |
| 10CFR-050.55E, 10CFR-50.55E, GO-1-82-0064, GO-1-82-64, NUDOCS 8203230653 | |
| Download: ML20042A653 (3) | |
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Docket Nos. 50 l+60/513 pgJ $0 55(e) Report Washington Public Power Supply System P.O. Box 968 3000 GeorgeWashingtonWay Richland, Washington 99352 (509)372-5000 March 5,1982 g G0-1 0064 (P 4 RECEIVED G
Nuclear Regulatory Commission I MAR 2 2 7982w [~1 Region V -
, c _,j 1450 Maria Lane, Suite 210 " 9
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Walnut Creek, California 94596 9 EE[$"% "
eQ G ffo Attention: Mr. R. H. Faulkenberry 4 9 $; ~2 Chief, Reactor Construction 3 g, g Projects Branch g a
Subject:
PROJECTS 1 & 4 DOCKET NOS. 50-460 AND 50-513 POTENTIALLY REPORTABLE CONDITION LUMPED MASS PIPE STRESS ANALYSIS LOADS
Reference:
Telecon CR Edwards, Supply System to J. Ekhart, Region V Nuclear Regulatory Commission, dated January 14, 1982.
In the above reference the Supply System informed your office of a potentially reportable deficiency under 10CFR50.55(e) concerning the use of lumped mass loads in the performance of pipe stress analysis.
Attachment "A" to this letter contains a description of the deficiency and what actions are being taken by the Project to verify the safety significance of the deficiency. Due to the nature and extensive amount of time necessary to complete the design analysis, we have concluded that this is a reportable condition in accordance with paragraph (IV) of 10CFR50.55(e). Thus, we are submitting Attachment "A" as an interim report. At this time, it is not possible to provide a final completion date for the subject design analysis. Therefore, the Supply System will provide your office with interim status reports on a semiannual basis.
If you have any questions or desire further information, please advise.
Np 1
D. W. Ma ur Program Director, WNP-1/4 Attachment DWM:MER:lm cc: CR Bryant, BPA/399 V. Stello, Director of Inspection, NRC A. Toth, NRC FDCC/899
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ATTACHMENT A s
! WNP-1/4 DOCKET NOS. 50.460 AND 50-513 REPORTABLE CONDITION 10CFR50.55(e)
LUMPED MASS LOADING ON PIPING SYSTEM ANALYSIS BACKGROUND During a recent peer review conducted at the UE&C home office by the Supply System relative to the design of piping systems, it was determined that not all piping analyses had been performed in accordance with approved UE&C procedures. In particular, it was determined that the use of lumped mass loads was not, in all cases, applied in accordance with the applicable procedure.
DESCkIPTION OF THE DEFICIENCY The cu'rrently approved UE&C procedure for performing pipe stress analysis requires that between every two (2) supports a lumped mass load is to be applied. Contrary to the procedure requirement, not all pipe stress analyses were performed in this manner. UE&C Engineering has stated that the deviations were conscious decisions made by the Engineer; however, no record of the assumption or the rationale to support the decision has been documented. The calculations in question had been checked and signed off by an independent second party. Under the current checking system, there is no specific requirement for the checker to verify the details of the dynamic modeling of the lumped. mass loads.
Verification of the model by the checker would have indicated whether or not lumped mass loads were accurately applied to the system.
SAFETY IMPLICATIONS The pipe stress analyses originally examined by the Supply System during the peer review and identified as not being consistent with the procedure have been reanalyzed by UE&C Engineering to include the lumped mass criteria. It was confirmed that the as-designed systems were adequate, without any modification. However, the reanalysis did confirm that piping stresses,and ,suppert loads did increase in one (1) of the reanalyzed
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systems, thus causing a degree of uncertainty as to whether design allowable limits will be maintaiaed in all cases. Stress margins exist for pipe support designs; therefore, the potential increases in support loads are expected not to impact design adequacy. However, a random sample investigation cannot conclusively eliminate the potential for '
- r; an isolated case; therefore, corrective actions will be taken as described below.
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CORRECTIVE ACTION The Supply System has identified the aforementioned discrepant conditions on Quality Finding Report (QFR) 99-1257 which was issued to UE&C on l February 25, 1982. The recommended corrective action documented in the QFR assigned UE&C the task of reviewing all piping system analyses I to identify which piping systems deviate from the criteria for lumped j mass spacing. Where discrepancies are noted, a reanalysis will be j performed unless the mass changes are considered to be trivial. Resolution 4
of trivial mass changes may be by parametric studies if design margins
, are demonstrated to be adequate. Further, the details of any parametric ,
studies used as justification for reported analysis results must be '
made available to the Supply System for evaluation.
The QFR also addresses the procedural inadequacy of the current " checking" program and requires upgrading of the procedure and further training of personnel to attain compliance with ANSI N45.2.ll.
STATUS
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4 Since UE8C has not yet responded to the QFR, we are unable to provide
- a schedule for completion of the corrective actions; therefore, we
] will provide interim status reports on a remiannual basis.
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