ML18066A847

Provides Notification of Error in ECCS Calculation Results as Defined in 10CFR50.46

ML18066A847
Person / Time
Site:	Palisades
Issue date:	01/20/1997
From:	Bordine T CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.)
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 9701290264
Download: ML18066A847 (2)

Text

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Power Thomas C. Bordlne Manager, Licensing

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MIClllGANoS Palisades Nuclear Plant: 27780 Blue Star Memorial Highway, Cov~*rt,. Ml. 49043 January 20, 1997 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555 DOCKET 50-255 - LICENSE DPR PALISADES PLANT NOTIFICATION UNDER 10 CFR PART 50.46 OF ERROR IN ECCS CALCULATlON RESULTS 10 CFR Part 50.46(a)(3)(ii) requires a 30-day report whenever a significant change or error in the Emergency Core Cooling System (ECCS) analysis occurs. "Significant" is defined in 10 CFR Part 50.46(a)(3)(i) as being a change of greater than 50°F in the peak cladding temperature. An input error by Siemens Power Corporation which .

resulted in an overprediction of peak cladding temperature by 104°F, was reported internal to Siemens on May 4, 1995. This error was not reported to Palisades until December 20,. 1996. This letter submits the required report.

Siemens internal correspondence dated May 4, 1995, described several errors found in the ECCS analysis for a postulated Large Break Loss of Coolant Accident (LB LOCA) at Palisades. Siemens had originally reported a peak clad temperature of 2095°F for Palisades cycle 12. With the errors corrected, the new peak clad temperature for Cycle 12 was 1991°F, a reduction of 104°F. This change should have caused Siemens to immediately notify Palisades based on 10 CFR Part 50.46(a)(3)(ii). However, Siemens concluded that formal notification was not required since they had determined that the errors were "conservative and there are no unresoved safety issues arising from these errors." The errors discussed in the Siemens letter were corrected during Cycle 12, and thus have no impact on the current ECCS analysis for a LB LOCA. Palisades was then

- - --and--remains in compliance with 1p CFR Part 50.46(b).

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• These errors were found during a special utility assessment of Siemens, initiated and led by Consumers Power Company, to follow up on recently reported LB LOCA methodology concerns. Once the errors were discovered, Siemens began an internal investigation of the event and determined that Palisades should be formally notified.

This notification was provided on December 20, 1996.

Additional reviews of past events were performed by Nuclear Fuel Users Group Assessment Teams and no other items significant to Palisades were found.

SUMMARY

OF COMMITMENTS This letter contains no new commitments and -no revisions to existing commitments.

~Q~ Thomas C. Bordine Manager, Licensing CC Administrator, Region Ill, USNRC Project Manager, NRR, USNRC NRC Resident Inspector - Palisades