ML20113A272

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Forwards Addl Info Describing Safety Relief Valve Transients to Clarify Re Confirmatory Issue 21 Concerning Suppression Pool Temp limits.Two-minute Limit for stuck-open Safety Relief Valves Deleted from Tech Specs
ML20113A272
Person / Time
Site: Perry  FirstEnergy icon.png
Issue date: 04/03/1985
From: Edelman M
CLEVELAND ELECTRIC ILLUMINATING CO.
To: Youngblood B
Office of Nuclear Reactor Regulation
References
NUDOCS 8504100137
Download: ML20113A272 (2)


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P O. BOX 5000 - CLEVELAND, OHIO 44101 - TELEPHONE (216) 622-9800 - lLLUMINATING BLDG. - 55 PUBLICSOUARE Serving The Best Location in the Nation MURRAY R. EDELMAN vicE PRESIDENT April 3, 1985 NUCt. EAR PY-CEI/NRR-0124 L Mr. B. J. Youngblood, Chief Licensing Branch No. 1 Division of Licensing U.S. Nuclear Regulatory Commission Washington, D.C. 20555 Perry Nuclear Power Plant Docket Nos. 50-440; 50-441 Additional Info. Regarding Confirmatory Issue No. 21, Suppression Pool Temperature Limits

Dear Mr. Youngblood:

This letter is submited to clarify our letter (PY-CEl/t4RR-0057L, June 29,1983) which provided supplementary information to resolve Confirmatory Issue 21, Suppression Pool Temperature Limits.

Table 2 of the referenced letter (attached)' stated that Perry's operating procedures would require the operator to scram the plant if a stuck-open safety relief valve could not be closed within two minutes or the suppression pool temperature increased to 110 F.

Based on recent discussions with the NRC staf f no technical justification could be identified to support scramming the reactor solely because a SRV was stuck open for two minutes. The suppression pool temperature is the critical parameter measured and the parameter on which the operator will take actions to shutdown the plant. The latest draft Technical Specifications 3.6.3.1 and 3.4.2.1 now require the plant to be shut down should the suppression pool temperature exceed 110 F.

The two minute limit was removed from Perry Technical Specifications 3.4.2.1 Action b, and will be removed from PNPP operating procedures.

If you have any questions, please call.

Very truly y rs, 850410013k!!bo 00 i PDR ADOC PDR Murray R. Ede man A Vice President Nuclear Group MRE:njc cc: Jay Silberg, Esq.

John Stefano (2)

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- TABLE 2

"+- DESCRIPTION OF SRV TRANSIENTS CASE 1 A - STUCK OPEN SRV DURING POWER WITH 1 RHR LOOP AVAILABLE

. ' Ev'ent initiated by.SORV occurring when pool temperature is at' TS 1 (95 F).

3, x

.- Operator initiates.RHR in pool cooling mode.

. RHR operating 10 minutes 'later.

.- At pool temperature of 110 F operator manually scrams reactor.

NOTE: Perry's operating. procedures will not specify the maximum number of attempts the operator will be allowed to use to reclose a stuck-open SRV.. However, Perry's operating procedures will require the operator to scram, when the suppression pool reaches the Technical Specification pool temperature limit for reactor scram orj if a SORV can't be' shut within two minutes.

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. The main condenser is available for approximately 20 seconds as a heat sink and can be reinstated at 1200 seconds at 30% steamline flow if vessel pressure is above 125 psia.

- . At pool temperature of 120 F, 3 additional SRV's are available to further depressurize the vessel at a cool down rate of 100 F/hr., if necessary.

. When vessel pressure reaches the THT shutdown cooling permissive pressure of 134.7 psia,-operator starts change over from RHR pool cooling mode to vessel shutdown cooling mode. This action is assumed to take 16 minutes.

There is no RHR on during this time. Vessel pressure is maintained with SRV'sLif necessary.

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