ML20147F945

Forwards Request for Addl Info Re Suppression Pool Temp Transients in Order to Complete Review of Topical Rept Nede 21078P Test Results Employed by GE for BWR Containment & Vertical Vent Loads

ML20147F945
Person / Time
Site:	Cooper
Issue date:	12/13/1978
From:	Desiree Davis Office of Nuclear Reactor Regulation
To:	Pilant J NEBRASKA PUBLIC POWER DISTRICT
References
NUDOCS 7812260051
Download: ML20147F945 (4)

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\ . [, . - December 13, i377 Docket No. 50-298 Nebraska Public Pow r District ATTN: Mr. J. M. Pilant, Director Licensing & Ouality Assurance P. O. Box 499 Columbus, Nebraska 68601 RE: SUPPRESSION POOL TEMPERATURE TRANSIENTS Gentl emen:

As part of our continuing review of the effects of elevated suppression pool temperatures on safety-relief valve (SRV) discharge loads, we have recently transmitted a request for additional information to General Electric (GE) regarding topical report NEDE 21078P, " Test Results Employed by GE for BWR Containment and Vertical Vent Loads."

Certain information which we require in order to complete our review of this report is of a pisnt-specific nature. Since you have adopted this topical report as part of your docketed material, we are transmitting to you the enclosed request for additional information.

You are requested to provide the information identified in the enclosure as soon as practical. Your projected submittal date for your response should be provided within ten days of your receipt of this letter.

The material contained in NEDE 21078P, the supplemental generic information requested from GE, and the plant-specific infomation requested in this letter will serve as part of the bases for our review of SRV loads in the Mark I Containment Long-Term Program (LTP).

Since the referenced report has been classified as proprietary under our rules, and since we have detemined that the requests contained in Part B of the enclosure are proprietary, they are, therefore, being withheld from public disclosure.

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Nebraska Public Power District -

2- December 13, 1977 We are aware that the Mark I Owners Group is developing a quencher-type SRV discharge device as part of the LTP. Al though ' the quencher devices are believed to be less sensitive to elevated pool = temperatures, it is our view that licensee responses to the enclosed request for additional information should be provided for each facility regardless -

of the- type of discharge device that will be utilized upon completion of the-LTP.

Silncerely, 7' ,

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Don .K. Davis, Acting Chief Operating Reactors Branch #2 Division of Operating Reactors

Enclosure:

Request for Additional Information cc: See next page e

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e Nebraska Public Power District December 13, 1977 cc Mr.w/

G.enclosure D. Watson,(non-proprietary)l:

General Counse .

Nebraska Public Power District P. O. Box 499 Columous, Nebraska 68601 RMr. Arthur C. Gehr, Attorney Snell & Wilmer 400 Security Building ,

Phoenix, Arizona 85004 Cooper Nuclear Station ATTN: Mr. L. Lessor

' Station Superintendent P. O. Box 98 Brownville, Neoraska 68321 Auburn Public Library 118 - 15th Street

' Auburn, Nebraska 68305 t

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l REQUEST FOR ADDITIONAL INFORMATION REGARDING SUPPRESSION P00L TEMPERATURE TRANSIENTS Part A: Non-Proo rieta ry 1.

Provide figures which depict the reactor pressure, safety / relief valve (SRV1 discharge mass flux, and suppression pool bulk temperature versus time for the following events which are based on current Tecnnical Specification limits:

(a) Stuck-open SRV during power operation assuming reactor scram at ten minutes after the suppression pool reaches a bulk pool temperature of 110 F and all RHR systems are operable.

(b) Same events as in (a) above with only one RHR train operable.

(c) Stuck-open SRV during hot standby assuming an initial 120 F bulk pool temperature and only one RHR train operable.

(d) Automatic Depressurization System (ADS) activated following a small line break assuming an initial 120 F bulk pool temperature and only one RHR train operable.

(e) Primary system is isolated and deoressurized at a rate of 100 F per hour with an initial 120 F bulk pool temperature and only one RHR train operable.

2.

Briefly describe the suppression pool temoerature monitoring system at your f acility and the relative location of the temperature sensors to the SRV discharge points.

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