ML19294B519

Ro:Reanalysis of RCS Pipe Restraints Revealed Less Conservative Design than Assumed on Two Reactor Coolant Hot Leg Whip Restraints Near Steam Generator Tops.Cause Unstated.Action During Refueling Outage in Eight Wks

ML19294B519
Person / Time
Site:	Davis Besse
Issue date:	02/15/1980
From:	Murray T TOLEDO EDISON CO.
To:
References
NUDOCS 8003040471
Download: ML19294B519 (1)

Text

February 15, 1980 TO: U. S. Nucicar Regulatory Commission Of fice of Inspection and Enforcement Region III Attention: Tom Tambling

SUBJECT:

Reportable Occurrence Per Technical Specification 6.9.1.8.1 Davis-Besse Unit 1 Mode 1, Power (WT) = 2772, and LoM (WE) = 923 An extensive re-analysis of the reactor coolant system pipe restraints revealed a design deficiency on two reactor coolant hot leg whip restraints near the top of each steam generator. The design is less conservative than assumed in the accident analysis of the safety analysis report and is being reported under Technical Specification 6.9.1.8.i.

Based on pipe stress analysis, a break would not occur at the postulated location on the reactor coolant piping. Analysis indicated an extremely low probability of a design basis- accident. The Company Nuc1 car Review Board has reviewed the occurrence and has determined that continued operation for eight weeks until shutdown fer the scheduled refueling outage does not compromise the health and safety of the public. Remedial action will be completed during the refueling outage.

Luis Reyes, NRC on-site inspector, was notified at 1440 hours0.0167 days <br />0.4 hours <br />0.00238 weeks <br />5.4792e-4 months <br /> on February 15, 1980.

Y $b Terry D. Murray Station Superintendent Davis-Besse Nuclear Power Station Toledo Edison company TDM/BRB/ljk h00A S

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