ML20004C593
| ML20004C593 | |
| Person / Time | |
|---|---|
| Site: | Big Rock Point File:Consumers Energy icon.png |
| Issue date: | 06/01/1981 |
| From: | Hoffman D CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | Crutchfield D Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8106040308 | |
| Download: ML20004C593 (2) | |
Text
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General offices: 212 West Mic.'igan Avenue, Jackson, MI 49201 e (517) 788-0550 V
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Director, Nuclear Reactor Regulation Att Mr Dennis M Crutchfield, Chief
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Operating Reactors Branch No 5 y
com US Nuclear Regulatory Commission
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DOCKET 50-155 - LICENSE DPR BIG ROCK POINT PLANT - SAFETY CONCERUS ASSOCIATED WITH PIPE BREAKS IN THE BWR SCRAM SYSTEM NRC letter dated April 10, 1981 provided NRC evaluation of the above subject and requested bcth a generic and plant specific evaluation of its conclusions and recommendations. The concerns expressed in this evaluation appear to be two-fold. These are the abilities to provide reactor core cooling and to centain reactor water inside primary containment. In presentation of this subject to the Advisory Committee on Reactor Safeguards (ACRS) Subcocmittee on Reactor Operations on March 10, 1981, Mr C Michelson, NRC, noted that the safety con-cerns associated with pipe breaks in the BWR scrsm systems are applicable to General Electric (GE) Mark I and II containment designs.
Consumers Power Company has reviewed the NRC letter dated April 10, 1081 and its attachments to determine its applicability to Big Rock Point (ERP). Our review indicates that the design and locatien of the BRP scram system make the concerns presented by Mr C Michelson not applicable to BRP. The following facts substantiate this conclusion:
- 1) 3RP was constructed in the early 1960's using a containment design that doesn't include a suppression pool (ie, basically a PWR type containment) and that does contain the entire hydraulic portion of the scram system, except for the suction line to the control rod drive (CRD) pumps. Therefore, the 3RP design is not susceptible to pipe breaks in the scra= system that result in loss of reactor water from containment. Postulated scram system pipe breaks are bounded by previous Emergency Core Cooling System (ECCS) analyses.
- 2) The location of ECCS components at 3RP eliminates the environmental effects concern resulting from scram system pipe breaks. The ECCS vater supply is provided by the fire system which is supplied by pumps external to containment. Post Incident recirculation ficv for the ECCS is also provided by pumps and a heat exchanger external to containment. In addition, all of the ECCS electrical components F106040307
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Mr Dennis M Crutchfield, Chief 2
Big Rock Point Plant June.1, 1981 located inside of containment are required to meet Electrical Equipment Qualification requirements (reference: Consumers Power letters dated Octcber 31, 1980 and January 30,1981).
- 3) In the 18 years operation of BRP, no indications or occurrences of scram system pipe breaks have been identified. This history agrees eith the GE conclusion that scram system piping failures have a low probability of occurrence.
GE letter MFN-091-81 dated April 30, 1981 from Glenn G Shervood to Darrell Eisenhut, NRC indicates that the safety concerns a.ss?ciated with pipe breaks in the BWR scram system is not applicable to BWR 6.erk III designs.
We have discussed this conclusion with GE and have ascertained that the same conclusion of non-applicability applies to BRP for essentially the same reasons.
Consumers Power has concluded based on the above that the safety concerns associated with pipe breaks in the BWR scram system are not applicable to Big Rock Point.
Therefore, this letter provides our response to both the generic and plant specific evaluation requests of NRC letter dated April 10, 1981.
David P Hoffman (Signed)
David P Hoffman Nuclear Licensing Administrator CC Director, Region III, USNRC NRC Resident Inspector - Big Rock Point l
s-CONSUMERS POWER COMPANY Big Rock Point Plant Response to NRC letter dated April 10, 1981 Docket No 50-155 License No DPR-6 At 'the request of the Commission and pursuant to sue Atomic Energy Act of 195h, and the Energy Reorganization Act of 197h, as amended, and the Commission's Rules and Regulations thereunder, Consumers Power Company submits our response to NRC letter dated April 10, 1981 entitled, " Safety Concerns Associated With Pipe Breaks In The BWR Scram System".
Consumers Power Company's response is dated June 1, 1981.
CONSUMERS POWER COMPANY By R B DeWitt (Signed)
R B DeWitt, Vice President Nuclear Operations Sworn and subscribed to before me this 1st day of June 1981.
Helen I Dempski (Signed)
(SEAL)
Helen I Dempski, Notary Public Jackson County, Michigan My fommission expires December ik, 1983 j
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