ML19249A245
| ML19249A245 | |
| Person / Time | |
|---|---|
| Site: | Midland |
| Issue date: | 08/15/1979 |
| From: | Howell S CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| HOWE-220-79, NUDOCS 7908210447 | |
| Download: ML19249A245 (1) | |
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Stephen H. Howell 4
Senior Vice President General Of fices: 1945 West Penell Road, Jackson. Michigan 49201. (517) 788 0453 August 15, 1979 Hove-221-79 Mr J G Keppler, Regional Director Office of Inapection and Enforcement US Nuclear Regulatory Commission Reglon III 799 Roosevelt Road Glen Ellyn, IL 6013T MIDLAIID UUCLEAR PL/JG -
UNIT 1;o 1, DOCKET no 50-329 UNIT no 2, DOCKET EO 50-330 SMALL EREAK/ REACT,0R COOLidif Pl14P OPERh2 ION IhTERACTION In accordance with the requirements of 10 CFR 50 55/c), this letter constitutes an interim report concerning a potentially unsafe ca.turtion if the reactor coolant pumps cre tripped after high system void fractions develop in the loop.
S.ecifict.11y, for the low probability events 4nvolvird a range of small reactor I
2 coolant system breaks (approxinately 0.025 ft' to 0.2 ft ), cnnlyses show that a high void fraction vill develop in the primary system during the ccurse of the occident. 10 CFR 50 Appendix K criteria may be exceeded if reactor coolant pumps are tripped after creation of this high void condition. TAW,Itidland's KSSS Supplier, has been working closely with the liRC staff (D1 Rosztozy) concerning this analysis.
MW reports that onalyses have been perforned which confirm a safe situation if the reactor coolant pumps are tripped promptly in the transient prior to establiching a high void fraction. mW mede a recommendation to the 177FA operating plants that "Upon receipt of an ESFAS actuation cauced by low RC pressure, all operatinS RC purps must be tripped imediately." CPCo is con-sidering an automatic / safety grade trip system.to accomplish the reco= ended action for the Midland Flant.
Another report, either interim or final, will be sent on or before October 19, 1979 l
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CC: Director of Office of Inspection and Enforcement Att: Mr Victor Stello,iSNRC (15) 761339 Director of Office of Management Information and Program Control, lGimC (1) 590s w W7 M