ML18051A307
| ML18051A307 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 02/10/1983 |
| From: | Toner K CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | Crutchfield D Office of Nuclear Reactor Regulation |
| References | |
| TASK-09-03, TASK-9-3, TASK-RR NUDOCS 8302160370 | |
| Download: ML18051A307 (2) | |
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consumers Power company General Offices: 212 West Michigan Avenue, Jackson, Ml 49201 * (517) 788-0550 February 10, 1983 Dennis M Crutchfield, Chief Operating Reactor Branch No 5 Nuclear Reactor Regulation US Nuclear Regulatory Commission Washington, DC 20555 DOCKET 50-255 - LICENSE DPR ;
PALISADES PLANT -
SEP TOPIC IX-3 "STATION SERVICE AND COOLING WATER SYSTEMS" -
WITHDRAWAL OF COMMITMENT TO INSTALL A FLOOD ALARM FOR THE WATER INTAKE BUILDING By letter dated March 17, 1982, Consumers Power Company responded to an NRC concern regarding the loss of the service water pumps due to a passive failure which results in flooding of the service water pump motors.
As indicated in the letter, Consumers Powe'r Company evaluated the NRC concern and concluded that certain actions were necessary for its resolution.
Accordingly, Consumers Power Company committed to verifying the adequacy of the intake structure drainage area and to installing appropriate devices to provide a control room alarm to warn the operator of intake structure flooding.
Subsequently, the aforementioned commitments were embodied in the final version of NUREG-0820 "Integrated Plant Safety Assessment, Systematic Evaluation Program, Palisades Plant" dated October 1982.
The purpose of this
~submittal is to describe the results of the aforementioned intake.structure drainage verification, to indicate that the need does not exist for the aforementioned alarm and to withdraw the commitment to install such an alarm.
By letter dated August 25, 1982, Consumers Power Company provided the results of the intake structure drainage verification.
As stated in the letter, calculations of drainage capacity revealed that adequate capacity exists to handle the largest postulated slot break.
As further stated in the letter, the equilibrium water level resulting from the Ao'"3~
flood would be approximately two feet above the floor.
It should be noted that this equilibrium level is approximately two feet and eight inches below the limiting components; the service water pump motors.
In an attempt to provide the NRC with an adequate rationale for withdrawing the commitment to install the flood alarm, Consumers Power Company recently reviewed its intake structure drainage verification calculations.
The review indicated that the calculations assumed a maximum slot break leak of 800 gpm OC0283-0007B-NL02 SS02lb0370 830210 PDR ADOCK 0500025.5 p
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DMCrutchfield, Chief Palisades Plant SEP TOPIC IX-3 February 10, 1983 as postulated by Branch Technical Position MEB 3-1.
In addition, the calculations assumed that only the four four-inch floor drains were available for draining (ie, the three 26-inch manholes were assumed not to be available for draining) and the doors to the water intake building were closed. The results of the calculations indicate that at an equilibrium level of two feet, the drainage flow is 1,081 gpm.
Since this drainage flow is greater than the maxiumum postulated slot break leak of 800 gpm, it was concluded that the drainage capacity is adequate and, therefore, no operator action is necessary to prevent flooding of the service water pump motors.
Although Consumers Power Company still considers it prudent to replace one solid 26-inch manhole cover with a grated cover to increase the drainage flow area (thereby increasing the margin between the calculated drainage flow and the maximum postulated slot break flow) Consumers Power Company does not consider it necessary to intall the flood alarm.
Therefore, Consumers Power Company intends to withdraw its commitment to install such an alarm.
Kerry A Toner Senior Licensing Engineer CC Administrator, Region III, USNRC NRC Resident Inspector - Palisades OC0283-0007B-NL02