ML19259A731

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Interim Rept Re Plant Conditions Following Sse.Assumes Loss of Offsite Power & non-safety Grade Sys Which Has No Engineering Evaluation to Address Unavailability of Pressurizer Heaters During This Condition
ML19259A731
Person / Time
Site: Midland
Issue date: 01/05/1979
From: Howell S
CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.)
To:
References
HOWE-4-79, NUDOCS 7901100227
Download: ML19259A731 (2)


Text

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{Q Senior Vice President General of fices: 1945 West Parnalt Fload, Jackson, Michigan 49201 * ($17) 788-0453 January 5, 1979 Hove h-79 Mr J G Keppler, Regional Director Office of Inspection and Enforcement Region III US Iluelear Regulatory Commission 799 Roosevelt Road Glen Ellyn, IL 60137 MIDLAUD IiUCLEAR PLA*;T UNIT N0 1, DOCKET no 50-329 UNIT E0 2, DOC ET no 50-330 PRESSURIZER HEATER SYSTEM Consumers Power Company informed the NRC on December T,1978 of a potentially reportable matter concerning the plant conditions following a Safe Shutdown Earthquake (SSE) and assun'ng the loss of offsite power and all non-safety grade systems. The specific issue is that no engineering evaluation is available which addresses the unavailability of pressurizer heaters during plant hot shutdown. This letter is an interim 50.55(e) report on this subject.

There are two options available which are being pursued, which should result in the resolution of this issue. They are as follevs:

1. CPCo and B&W are investigating the feasibility of performing a conplete engineering evaluation to define the plant response to unavailability of pressurizer heaters during plant hot shutdown. An engineering plan to conduct this or alternative engineering evaluations or a decision that this option is not viable vill be available by February 28, 1979 Also to be investigated are specific operating procedures which could be taken following an SSE to assure acceptable plant conditions. It may well be possible to demonstrate that the availability of heaters is not a requirement.
2. Consumers has requested B&W to perform an engineering evaluation to determine if a sufficient number of pressuriser heaters would be operable following an SSE. The methodology to be employed is not finalized at this time.

As a matter of information, CPCo made a decision in November, in order to enhnnee plant licensability, to upgrade to Class lE pressurizer control and power supply for a portion of the heaters in each pressurizer.

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Another interim 50.55(e) report will be provided on or before March 16, 1979 at which time we vill provide the status on the above two options.

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, , YM WV(k CC: Director of Office of Inspection & Enfcrcement Att: Mr John G Davis, Acting Director, USHRC (15)

Director, Office of Managenent Information & Program Control, USURC (1) s