ML20076J544

Comments on 810629 Generic Evaluation of NUREG-0737,Item II.E.4.2 Containment Purge & Vent Valve High Radiation Isolation. Automatic Isolation of Containment Purge & Vent Valves on High Containment Radiation Unnecessary

ML20076J544
Person / Time
Site:	Hatch
Issue date:	08/31/1983
From:	Nix H GEORGIA POWER CO.
To:	Stolz J Office of Nuclear Reactor Regulation
References
RTR-NUREG-0737, RTR-NUREG-737, TASK-2.E.4.2, TASK-TM NED-83-440, TAC-56049, TAC-59542, NUDOCS 8309070229
Download: ML20076J544 (2)

Text

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Georg a Pow Company

, 333 Pedrnant Avenue

< Atlanta. Gecwg!a 30308

- Telephone 404 526-6526 MaAng Address Pos' Offce Box 4545 m At anta. Georgia 30302 Georgia Power Power Generation Department - 44 August 31, 1983 Director of Nuclear Reactor Regulation Attention: Mr. John F. Stolz, Chief Operating Reactors Branch No. 4 Division of Licensing U. S. Nuclear Regulatory Consnission Washirgton, D. C. 20555 NRC DOCKm s 50-321, 50-366 OPERATING LICENSES DPR-57, NPF-5 ENIN I. HATCI NUCLEAR PIANP UNITS 1, 2 NUREG-0737 ITDi II.E.4.2(7) CONTAINMENT PUIGE AND VENT VALVE HIGH PADIATION ISOLATION Gentlemen:

The NR Owners Group subnitted a generic evaluation of the subject item by T. J. Dente's letter of June 29, 1981. The Owners Group position, which was endorsed by Georgia Power Conpany (GPC) was that automatic isolation of contairunent purge and vent valves on high containment radiation was not necessary for Mark I and II plants. %e basis for this conclusion was that:

(1) the purge and vent valves are normally closed, (2) there are existing separate, diverse signals for automatic closure of these valves, (3) various signals would alert operators to manually close these valves, and (4) the radiological consequences of a break which would not automatically isolate the purge and vent valves are acceptably low. Additional information supporting this position was provided by the Owners Group in a November 19, 1981, meeting and by T. J. Dente's letter of June 14, 1982.

l Your letter of July 29, 1981, transmitted to GPC two NRC staff Safety Evaluations in which it was concluded that the Owners Group position was not acceptable. %e staff considers a high radiation isolation signal necessary l to reduce the reliance on operator action and on indirect parameters such as l high drywell pressure and low reactor water level for timely isolation of I purge and vent valves.

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! 8309070229 830831 PDR ADOCK 05000321 P PDR

Georgia Power A Director of Nuclear Reactor Regulation Attention: Mr. John F. Stolz, Chief Operating Reactors Branch No. 4 August 31, 1983 Page Two While GPC shares the staff's desire to prevent an excessive release of radioactivity through purge and vent valves during accident conditions, we maintain- that the present containment isolation design at Plant Hatch adequately serves this purpose. We consider the addition of a high radiation signal for purge and vent valve isolation an unnecessary conservatism.

However, we are willing to make this modification to the Hatch units in the interest of resolving Item II.E.4.2(7) . GPC will sutait a description of the intended modification by November 1, 1983. Installation will take place during the first refueling outage follc, wing conpletion of _ design and parts procurement. We estimate that this will be accomplished for Unit 1 by the end of the refueling outage following Cycle 7, currently scheduled for 1985, and for Unit 2 by the end of the refueling outage followi-- Cycle 5, currently scheduled for 1985. Because this modification represent.s an increase in the conservatism of the contairnent isolation design rather than correction of a deficiency, GPC considers no interim compensatory measures necessary and plans no action in this regard.

Please contact this office if there are any questions.

Very truly yours, H. C. Nix, Jr.

qv General Manager JH/mb xc: J. T. Beckham, Jr.

t Senior Resident Inspector l

J. P. O'Reilly (NRC-Region II) l 700775 W - - . , . _ - .- - - -