ML20198E281

Followup Part 21 & Deficiency Rept Re Signal Failure Potential in Safety Injection Recirculation Path.Initially Reported on 850724.Control Logic for Valves Will Be Changed

ML20198E281
Person / Time
Site:	Point Beach
Issue date:	10/30/1985
From:	Fay C WISCONSIN ELECTRIC POWER CO.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
CON-NRC-85-116, REF-PT21-85, REF-PT21-85-462-000 PT21-85-462, PT21-85-462-000, VPNPD-85-498, NUDOCS 8511130268
Download: ML20198E281 (2)

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lHsconsin Electnc eom couem 231 W. MICHIGAN, P.O. BOX 2046. MILWAUKEE, WI 53201 VPNPD-85-498 '

I NRC-85-ll6 ,

j October 30, 1985 Mr. J. G. Keppler, Regional Administrator Office of Inspection and Enforcement, Region III U. S. NUCLEAR REGULATORY COMMISSION 799 Roosevelt Road Glen Ellyd, Illinois 60137

Dear Mr. Keppler:

DOCKET NOS. 50-266 AND 50-301 SINGLE FAILURE POTENTIAL IN SAFETY INJECTION RECIRCULATION PATH POINT BEACH NUCLEAR PLANT, UNITS 1 AND 2 The purpose of this letter is to follow up with information regarding our final estrective actions and design changes which we are implementing to ensure flow in the recirculation path for the safety injection pumps. This subject and our initial corrective-

' actions were discussed in our 10 CFR 21 report dated July 24, 1985.

-The corrective actions involve preventing valves SI-897A or B from failing closed and stopping all recircula+ ion for both safety injection pumps. These air-operated valves normally fail closed l on loss of instrument air, however, the valves each have a manual operator which can override the air operator. As part of the initial l corrective action the. valves were opened with the manual operator.

This prevents either. valve from failing closed on a loss of instrument air or loss of control power to the valve operator.

Prior to initiating containaient sump recirculation, the Emergency Operating Procedures require these manual operators to be positioned such'that the valves can be closed. A special order has been issued to provide for the use of locks to establish administrative controls over the operation of the SI-897A and B valves and SI-851A and B containment sump isolation valves (FSAR Figure 6.2-1, Sheet 1 of 2, shows the SI-897A and B and the SI-851A and-B valves) whenever these. valves must be operated for, testing 8511130268 851030  !

ADOCK 05000266 PDR S. PDR O g HOV 41985

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~ Mr .3 J. .G..Keppler October-30, 1985 Page 2 purposes or in the unlikely event of an accident requiring containment sump-recirculation. These administrative controls

. prevent.the: opening;of!either SI-851 valve:until one of the SI-897.. valves _is fully: closed. These,short-term corrective actions were outlined in our letter.to you of July 24-and'have been implemented.

-The following-additional corrective actions'will be taken to further address the single failure possibilities discussed in-LtheLJuly 24 letter. The control-logic for the valves will be= ,

-changed.to "hard wire" the administrative controls' discussed above. The control. logic ~for the SI-851A or B will be modified to prohibit either; valve from leaving its' closed position until

one of the-SI-897 valves has been fully closed. The-control logic for the SI-897A or'B valves will also be modified to preclude opening either valve if either one of.the SI-851 valves is not closed._ These modifications will provide safeguards against inadvertent opening of the SI-897Evalves during residual heat removal- (RHR)' recirculation from the containment sump. The portion of'the control' power circuit for valves SI-897A and B,.which

'provides an alarm in the control room whenever either of the valves is shut, will also be modified such that a loss of power

.to-the circuitLor closure of either. valve'will cause an alarm'to

' occur.-

tu iIld J We believe these modifications, together with the corrective-actions already taken, will: ensure the safety injection pumps are

=not damaged by-loss of recirculation flow during those evolutions

- where-the pump is runningcunder pressure conditions exceeding their shutoff head. They will also prevent the release of radioactive

< materialivia the path, created'if:either of the SI-897. valves is open at;the same time either of the SI-851 valves is open

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,during containment sump =recirculationc We expect to get these changes throughsour;modificati.on approval

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process and completeLthe necessary control!1ogic rewiring within

.six-months. Please contact us if you have any questions concerning

-this matter.

Very truly yours,

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C.'W. Fay Vice President Nuclear Power-Copies' to H. R. Denton, NRC Washington i J. I. McMillen, NRC Region III l l NRC Resident Inspector j p

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