ML19210C520
| ML19210C520 | |
| Person / Time | |
|---|---|
| Site: | Big Rock Point File:Consumers Energy icon.png |
| Issue date: | 10/31/1979 |
| From: | Bixel D CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| IEB-79-24, NUDOCS 7911150063 | |
| Download: ML19210C520 (2) | |
Text
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5 General Offices: 212 West Michigan Avenue, Jackson, Michigan 49201 e Area Code 517 708-0550 October 31, 1979 Mr James G Keppler Office of Inspection and Enforcement Region III US Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, IL 60137 DOCKET 50-155 - LICENSE DPR BIG ROCK POINT PLANT - CONSUMERS POWER COMPANY RESPONSE TO IE BULLETIN 79-24: FR0 ZEN LINES Attached is Consumers Power Company's response to IE Bulletin 79-24 (Frozen Lines).
IE Bulletin 79-24 dated Septer.ber 27, 1979 requested that all plants report the results by 10/31/79 of reviews to determine that adequate protective measures have been taken to assure that safety-related process, instrument and sample lines do not freeze during extremely cold weather.
Consumers Power Company's review is divided into two parts:
Part 1 of the discussion addresses critical safety-related systems (standby systems that are required to cope with postulated accidents).
Part 2 of the discussion addresses recent freezing problems in noncritical safety-related systems (systems that are not required to be operable to cope with postulated accidents).
1.
Critical Safetv-Related Systems Heating capacity and other design features have proven adequate to prevent freezing in areas where critical safety-related equipment is located.
Checks are conducted to assure normal conditions on a periodic basic, in all such areas which are supplied by heat sources other than the plant heating boiler. Three such areas are involved:
A.
The screen, well and pump house is provided with thermostatically controlled electric heat and abnormal conditions would be detected during routine inspection rounds made by Operations personnel.
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2 B.
The post-incident Leat exchanger and pump room is provided with thermostatically controlled electric heat and abnormal temperature conditions would be detected by Operations personnel during routine inspection rounds.
It is probable that this room would never experience freezing conditions since it is below grade with limited potential for outside air circulation.
C.
The emergency diesel generator room is provided with thermostatically controlled electric heat and room low temperature remote alarm.
In addition, electric heating features are included for various diesel engine components.
The room and the heating equipment for the engine are checked during routine inspection rounds by Operations personnel.
Freeze protection features outlined in the Cold Weather Checkoff List are done on a seasonal basis in late October for the above areas as well as noncritical safety-related equipment and nonsafety-related equipment.
Our experience over seventeen years of operation and our continued surveillance provides an adequate level of assurance that all critical safety-related systems will not be subject to inadvertent inoperability due to freezing.
2.
Noncritical Safety-Related Systens Freezing has been experienced in only two systems in this category during the entire plant operating history.
A.
The stack gas effluent radiation monitor sample line was modified by heat tracing and insulating in November 1976 to preclude freezing of condensing moisture.
This modification has proven to be effective.
B.
The discharge canal liquid radiation sampling system has experienced freezing problems and a similar modification to prevent freezing is expected to be completed this fall.
Pending the modification on the canal sample system, Consumers Power Company believes that all safety-related systems in this category are adequately protected from freezing.
David A Bixel (Signed)
David A Bixel Nuclear Licensing Administrator CC Director, Office of Nuclear Reactor Regulation D'. rector, Office of Inspection and Enforcement 1332 535