ML20128F894

Forwards Request for Addl Info Re Util 840629 & 0720 Responses to Generic Ltr 84-09 Concerning Recombiner Capability Requirements of 10CFR50.44.Response Requested within 45 Days of Ltr Receipt

ML20128F894
Person / Time
Site:	Cooper
Issue date:	05/15/1985
From:	Vassallo D Office of Nuclear Reactor Regulation
To:	Pilant J NEBRASKA PUBLIC POWER DISTRICT
References
GL-84-09, GL-84-9, NUDOCS 8505290754
Download: ML20128F894 (3)

Text

h May .1'5, 1985 Docket No. 50-298' DISTRIBUTION tEEEETffei NRC PDR L'o&l~ PDR ' ' .0RB#2 Rdg HThompson OELD p Mr.- J. M. Pilant, ' Technical ELJordan BGrimes

. Staff Manager . JPartlow ESylvester Nuclear Power Group SNorris . -ACRS (10)_

Nebraska Public Power District Gray File ' JKudrick Post Office Box'499 Columbus -Nebraska 68601

~

SUBJECT:

REQUEST FOR' ADDITIONAL INFORMATION -

HYDROGEN RECOMBINER CAPABILITY

.Re: Cooper Nuclear Station We have reviewed your submittals dated June 29, 1984 and July 20, 1984

- responding to Generic Letter 84-09, "Recombiner Capability Requirements of 10 CFR 50.44(c)(3)(ii)." We find that additional-information:is required to pemit completion of our review. Our Request for Additional Infomation

-(RAI) 'i s . enclosed.- Please respond to the RAI within 45 days of_ receipt of this letter.

The reporting and/or recordkeeping requirements of this letter affect fewer than ten respondents; therefore, OMB clearance is not required under P.L.96-511.'

Sincerely,-

-i Original signed by/

=Domenic B..Vassallo, Chief Operating Reactors Branch:#2 Division of. Licensing As stated

~

'CC:

lSee next-page hgf]$$ 8

-g&/

ORB!2:DL' ORBf2:DL CS ORB #2:DL SN rs ESylvester:ps JK DVassallo 1 05/11/85 05/ 14/85 05/ /85 05//f785

r_____. _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ . _ - ________

Mr. J. F. Pilant Cooper Nuclear Station I

!!ebraska Public Power District cc:

Mr. G. D'. Watson, General Counsel Nebraska Public Power District Post Office Ecx 499 Columbus, Nebraska 68601 ,'i Mr. Arthur C. Gehr, Attorney '

Snell & Wilmer

. 3100 Valley Center Phoenix, Arizona 85073

' Cooper Nuclear Station ATTN: Mr._ Paul Thomason, Division Manager of Nuclear Operations Post Office Box 98 '

Brownville, Nebraska 68321 l -

Director I

Nebraska Dept. of Environmental Control Post Office Box 94877 State House Station p ' Lincoln, Nebraska 68509 I

( Mr. h'illiam Siebert, Commissioner f Nemaha County Board of Commissioners Nemaha County Courthouse Auburn, Nebraska 68305 Mr. Dennis DuBois U. S. Nuclear Regulatory Commission Resident Inspector

. Post Office Box 218 Brownville, Nebraska 68321 Robert D. Martin Regional Administrator Region IV Office U. S. Nuclear Regulatory Commission 611 Ryan Plaza Drive, Suite 1000 Arlington, Texas 76011 H. Ellis Simmons, Director Division of Radiological Health Department of Health 301 Centennial Mall, South Post Office Box 95007

. Lincoln, Nebraska 68509

ENCLOS'URE REQUEST FOR ADDITIONAL INFORMATION HYDROGEN RECOMBINER CAPABILITY COOPER NUCLEAR STATION

1. Provide a list of all pressurized systems within the containment using atmospheric air. Include the volumes and flowrates of air that could be released into the containment in case of system failure. Also, describe the isolation provisions for these systems and provide a reference to relevant drawings. In general, justify the use of atmospheric air within the containment.

?. In case of a pressure drop in the normal Nitrogen Supply System for the drywell pneumatic system, the check valve between the Nitrogen Supply System and Instrument Air System would automatically open and inject atmospheric air into the drywell piping. We do not find automatic actuation of a back-up air system to be in compliance with the criteria provided in Generic Letter 84-09. To be acceptable, the system should be designed such that an inadvertent inleakage of air can be prevented and adequate administrative controls should be developed to prevent the use of the back-up air system during power operation and during post-accident situations. If the air supply is used during cold shutdown modes, give the procedures preventing start-up of the plant whenever the drywell accumulators are filled with air.

3. Plants such as Cooper are required by 10 CFR 50.44(g) to be provided with a post-accident combustible gas control system. In meeting this requirement, the staff requires that the hydrogen generation rates stipulated in Regulatory Guide 1.7 be used in evaluating the adequacy of those systems which were a part of the original design basis accident (DBA) analysis. Consequently, you are requested to show how Cooper meets the requirements of 10 CFR 50.44(g) and show that the hydrogen generation rates used in the combustible gas control analysis comply with Regulatory Guide 1.7.

4. If it is your intention to obtain approval for the currentl air CAD system as a means of compliance with 10 CFR 50.44(g)y-designed

, note that this CAD system would be a potential source of oxygen to the containment following a LOCA. As such, it would not meet Criterion 3 of Generic Letter 84-09. It is necessary that Cooper meet all three criteria of Generic Letter 84-09 to demonstrate that the facility does

not rely primarily on purge /repressurization for post-LOCA combustible gas control. Plants that rely on purge /repressurization as the primary means of post-LOCA combustible gas control are reovired by 10 CFR 50.44(c)(3)(ii) to be provided with the capability for hydrogen-oxygen recombination. Therefore, if you conclude in response to Item 3 above that a CAD system is required to meet 10 CFR 50.44(g), please discuss how you intend to comply with 10 CFR 50.44(c)(3)(ii) without either converting your air CAD system to a nitrogen CAD system or adding recombiner capability.

- . . -