ML19260D958
| ML19260D958 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 01/31/1980 |
| From: | Opeka J NORTHEAST UTILITIES |
| To: | |
| References | |
| MP-1-1412, NUDOCS 8002120669 | |
| Download: ML19260D958 (2) | |
Text
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January 31, 1980 MP-1 -1412 Mr. Boyce H. Grier Director, Region I Office of Inspection and Enforcement U. S. tiuclear Regulatory Commission 631 Park Avenue King of Prussia, Pennsylvania 19406
Reference:
Provisional License DPR-21 Docket tio. 50-245 Reportable Occurrence R0-80-02/1P
Dear Mr. Grier:
This letter is forwarded to prohde prompt notification of Reportable Occurrence R0-80-02/IP as required by the Millstone Unit 1 Technical Specifications.
On January 31, 1980 after evaluating infomation gathered as a result of a meeting with the General Electric Company it became apparent that an error existed in the analysis described in the Safety Analysis Report that could have pemitted reactor operation in a manner less conservative than assumed in the analysis.
Thte Technical Specifications establish MAPLHGR (Maximum Average Planar Linear Heat Generation Rates) limits based on Emergency Core Cooling System capabilities.
Investigation by the General Electric Company has found that Low Pressure Coolant injection (LPCI) loop selection logic instrumentation is insensitive to low pressure differentials that would result from a small break, less than.1 f t, in the discharge side of the recirculation loops.
This could result in the LPCI System injecting to the brcken loop.
This scenario combined with a loss of normal power and assuming the worst single failure (loss of the Gas Turbine Generator) would result in less LPCI flow getting into the reactor vesse' than assumed in the accident analysis hence resulting in higher peak clad temperatures than previously analyzed.
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1951 301 9
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Mr. Boyce H. Grier Page 2 At this time the plant is operating at approxinately 40 percent while repairs are being made to a hanger associated with the isolation condenser.
Prior to returning to a higher power level, administrative limits will be placed on operation to insure compliance with ECCS criteria.
Further infomation will be provided in the followup 14 day report.
Yours truly, J. F. Opeka Station Superintendent Hillstone fluclear Power Station JF0/PJP:lls cc: Director, Office of ifanagement Infomation and Program Control, Washington, D.C. (2) ms 1951 302