ML19257A293

Forwards Request for Addl Info Re Util 790109 & 0829 Responses to NRC Re Containment Purging. Electrical Review Criteria Encl.Requests Reply within 60 Days

ML19257A293
Person / Time
Site:	Hatch
Issue date:	12/10/1979
From:	Ippolito T Office of Nuclear Reactor Regulation
To:	Whitmer C GEORGIA POWER CO.
References
TAC-42603, TAC-42604, TAC-51984, TAC-51985, NUDOCS 8001030582
Download: ML19257A293 (5)

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NUCLEAR REGULATORY COMMISSION g g,, g/ j WASHINGTON, D. C. 20555 I)..

• DECEYBER 1 0 1979 Docket Nos. 50-321 and 50-366 Mr. Charles F. Whitmer Vice President - Engineering Georgia Power Company P. O. Box 4545 Atlanta, Georgia 30302

Dear Mr. Whitmer:

You responded by letters dated January 9,1979 and August 29,1979 to our letter of November 29, 1978 concerning Containment Purging.

In your response you have attempted to justify unlimited purging during power operation.

During the course of our review of your submittals, we identified several areas where additional information is necessary to allow unlimited purging during power operation as you propose at Hatch Nuclear Plant Units Nos.1 and 2.

The enclosed request for additional information was discussed with you during a meeting on October 4,1979.

In addition, you were provided draft review criteria we are using for the electrical portion of the review. This review criteria is also enclosed.

Please provide your response within 60 days of receipt of this letter.

Feel free to contact our office if you have any questions on this request for additional infonnation.

Sincerely n

Thomas A. Ippolito, Chi 3f Operating Reactors Branch #3 Division of Operating Reactors

Enclosures:

1.

Request for Additional Information 2.

Electrical Review Criteria cc w/ enclosures:

7 7

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J G

iUU see next page gn 8 001 OG O U i-

Mr. Charles F. Whitmer Georgia Power Company 2

cc:

G. F. Trowbridge, Esquire Shaw, Pittman, Potts and Trowbridge 1800 M Street, N. W.

Washington, D. C.

20036 Ruble A. Thomas Vice President P. O. Box 2625 Southern Services, Inc.

Binningham, Alabama 35202 Ozen Batum P. O. Box 2625 Southern Services, Inc.

Birmingham, Alabama 35202 Mr. William Widner Georgia Power Comoany Power Generation Department P. O. Box 4545 Atlanta, Georgia 30302 Mr. L. T. Gucwa Georgia Power Company Engineering Department P. O. Box 4545 Atlanta, Georgia 30302 Appling County Public Library Parker Street Baxley, Georgia 31413 1bb7 34h Mr. R. F. Rogers U. S. Nuclear Regulatory Commission P. O. Box 710 Baxley, Georgia 31513

ENCLOSLRE 1 REQUEST FOR ADDITIONAL INFORMATION FOR CONTAINMENT PURGE SYSTEM AND CONTAINMENT VENTING SYSTEM FO..

HATCH NUCLEAR STATION, UNITS 1 AND 2_

DOCKET NOS. 50-321/366 1.

With regard to the containment purge and venting system, provide the following infomation:

Discuss the provisions made to ensure that isolation valve a.

closure will not be prevented by debris which coeld poten-tially become entrained in the escaping air and stear..

b.

Discuss the provisions made for testing the availability of the isolation function and the leakage rate of the isolation valves, individually, during recctor operation.

Specify the amount of containment atmosphere released through c.

the purge and vent isolation valves for a spectrum of break sizes during the maximum closure time allowed in your Technical Specifications.

d.

Provide an analysis to demonstrate the acceptability of the provisions made to protect structures and safety-related equipment, e.g., fans, filters, and ductwork, located beyond the purge system isolation valves against loss cf " unction from the environment created by the escaping air and steam, e.

For the containment purge isolation valves, specify the differential pressure across the valve for wilich the maximum leak rate occurs.

Provide test results (e.g., from vendor tests of leakage rate versus valve differential pressure) which support your conclusion.

2.

Describe the modifications mentioned in your August 10,1979 and August 29, 1979 letters. When will these modifications be completed?

Does the system as modified conform with the following criteria:

a.

Overriding one type of safety actuation signal rust not cause the blocking of any other safety actuation signal.

b.

Sufficient physical features are provided to fa:ili ate administra-

, tive control.

System level annunciation of the overridden sta us is provided c.

for every safety system inpacted when any overr'de is active.

1667 34ii

. 3.

Are the two units identical in respect to safety actuation circuits?

Describe any differences.

4.

Your letter of August 29, 1979 indicates that the containment spray injection valves have a (single?) key lock bypass switch which bypasses all isolation signals. Address how this switch is justified from a single failure standpoint.

5.

Clarify if purging requires the use of the key lock bypass switch above or below 850 psig steam line pressure. Address how this switch is justified from a single failure standpoint.

6.

Describe keylocked bypass switches and interfaces with valve control circuits.

7.

Describe valve position switches and features to facilitate administra-tive control.

8.

If the high radiation logic calls for valve closure, do both valve trains respond?

9.

The Hatch 2 FSAR indicates that the radiation " upscale trips" meet the requirements of IEEE-279. Discuss the qualifications of other portions of the radiation monitoring channels.

10. Your letter of August 29, 1979 indicates that the analysis of a LOCA while purging through the 18" lines is unacceptable.

'n' hat prevents purging through the 18" lines during reactor operation?

11. The FSAR describes the hybrid "one out of two taken Nice" signal that represents the containment pressure and reactor vessel level.

Is this descriptive of one out of two independent channels of actuation signals?

166734'p

ENCLOSURE 2 ELECTRICAL REVIEW C:ITE:.I-Ine crimary intent of this evaluation is to deter -i e i# - e #:llcwing N:~

staff criteria are met for the safety sigel-tc al'. Our;e ar:.ertila:icn isolation valves:

(1) Criterion no.1 - The overriding

• of one tyce of safety actuation signal (e.g., radiation)must not cause the blockin; cf 3.1y other type of safety actuation signal (e.g., pressure) tc the isolation valves.

(2)

Criterion no. 2 - Sufficient physical features (e.g.

ka/ lock switches) are provided to facilitate adeouate ac-i-istra-ive control s.

(3) Criterion no. 3 - The syctem-level annunciaticq of r.e :verridden status is provided for every safety syster ' tac e:,ne any override is active.

Incidental to this review, the following acditional NRC staf# design critcria were used in the evaluation:

(1) Criterion no. 4 - Diverse signals should be orovicac :: ir.itiate isolation of the containment ventilation syste.

5: sci'i cally,

containment high radiation, safety infection actua-ion, ard containment high pressure should automatically initiate CVI.

his 's in conformance with Branch Technical Positior. 6.' cf Se:ti:n 6.2.4 cf the Standard Review Plan.

(2)

Criterion no. 5 - The instrumentation and con:rci syste s orovided to initiate CVI should be designed an: cual'fiec as sa#aty-grade equioment.

(3)

Criterion no. 6 - The overriding or rasetting' cf - e isc~.ation actuation signal should not cause the automatic reocenir.g of any ' solation / purge val ve.

'The following definition is given for cla-ity of use i : th's evaluatior.:

Override:

The signal is still present, ar.d i-is b.o:2.sd ' orter to perform a function contrary Ic the s'; a'..

Rese :

The signal has come anc gone, ar.d r.e :i-c.': i: beirg clea-ec to return it to the no' mal corti:icr P00R~0 RIEL 1667 34'6