ML18046B072
| ML18046B072 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 11/16/1981 |
| From: | Crutchfield D Office of Nuclear Reactor Regulation |
| To: | Hoffman D CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| References | |
| REF-GTECI-B-68, REF-GTECI-PV, REF-GTECI-SY, TASK-05-07, TASK-5-7, TASK-B-68, TASK-OR, TASK-RR LSO5-81-11-304, NUDOCS 8111200705 | |
| Download: ML18046B072 (5) | |
Text
-i.'*
Docket No. 50-255 LSOS11-034 Mr. David P. Hoffman Nuclear Licensing Administrator Consumers Power Company 1945 W. Parnall Road Jackson, Michigan 49201
Dear Mr. Hoffman:
November 16, 1981
SUBJECT:
SYSTEMATIC EVALUATION PROGRAM TOPIC V-7, REACTOR COOLANT PUMP OVERSPEED - PALISADES Enclosed is a copy of our evaluation of Systematic Evaluation Program (SEP)
Topic V-7. This topic is being reviewed generically by NRC under generic issue B-68 "Pump Overspeed During LOCA 11
- For the reasons described in the enclosed SER this topic is considered complete.
Enclosure:
As stated cc w/enclosure:
See next page Sincerely, Dennis M. Crutchfield, Chief Operating Reactors Branch No. 5 Division of Licensing
( 8111200705 811116~
I ~DR ADOCK 05000255:
PDR NRC FORM 318 (10-80) NRCM 0240 OFFICIAL RECORD COPY USGPO: 1981-335-960
Docket No. 50-255 LS 05 11-034
- *Mr. David P. Hoffman e.:
UNITEDSTATES:
.e NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 November 16, 1981
- Nuclear Licensing Administrator Consumers Power Company l 945 *W. Parna 11 Road Jackson, Michigan 49201
Dear Mr. Hoffman:
SUBJECT:
SYSTEMATIC.EVALUATION PROGRAM TOPIC V-7, REACTOR COOLANT PUMP OVERSPEED - PALISADES Enclosed is a copy of.our evaluation of Systematic Evaluation Program (SEP)
T9pic V-7.
This topic is being reviewed generically by NRC under generic issue B-68 11 Pump Overs peed During LOCA~'.
For the reasons described in the enclosed SER this topic -is con.sidered *-
complete.
Enclosure:
As stated cc w/enclosure:
See next page Sincerely,
~1/.7Y~
r Dennis M. Crutchfield, Chief Operating Reactors Branch No. 5 Division of Licensing
SYSTEMATIC EVALUATION PROGRAM TOPIC V-7 PALISADES Topic:
V-7 Reactor Coolant Pump Overspeed I.
INTRODUCTION The purpose of this topic review is to assure that, in the event of a major LOCA, a reactor coolant pump assembly is not driven to a speed which would cause a structural failure of the unit and result in missiles which could increase the consequences of a LOCA.
II.
REVIEW CRITERIA Standard Review Plan (SRP} Section_S.4.l.1,-Regulatory Guide (R. G.*)
1. 14.
I I I.
RELATED SAFETY TOPI CS AND INTERFACES 111-10.B, Pump Flywheel Integrity*
IV.
REVIEW GUIDELINES See Evaluation V.
EVALUATION A ~eview of reactor coolant pump overspeed due to LOCA is part of an ongoing generic review.
The related generic task is B-68, ~Pump
-2..
civerspeed During LOCA
~
The results of the ~RC generic inv~stigation to date have not identified additional protective measures that should be required to prevent excessive pump overspeed during a LOCA.
The pump flywheel integrity at Palisades has been assured by an inservice inspection of the flywheel to detect flaws which could lead to flywheel failure.
The staff safety evaluation of the Palisades Pump Flywheel ISi program was issued on May 15, 1981.
The probability of attaining an overspeed following a LOCA which is s*ufficient to cause loss of flywheel integrity is very remote.
This probability woi1ld be the product of the conditional probabilities of a break of a large primary system coolant pipe, the probability of*
failure of the pipe restraints so that the break could become a double-ended guillotine break (calcu1ations show a significantly small~r over-speed for a realistically constrained guillotine break) and the probability
.of a loss of electric power to the pump so that there is no electric braking effect and the pump is permitted to accelerate freely. Also, the pump would have to r~main free spinning.
Seizing of the shaft or motor components could prevent overspeed.
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- On the basis of low probability of the sequence of events necessary and because*of the licensee's performance of an inservice inspection program for the flywheel, continued operation of the Palisades reactor is accep-tabl~. If upon completion of the staff's generic r~view of task ~~68, new requirements are determined to be necessary to minimize pump overspeed in the event of a LOCA, these new requirements will be reviewed for appli-cability on all oper~ting reactors.