ML20088A293

Responds to 840326 Request for Clarification of 831026 Submittal Describing Alternate Shutdown Capability (10CFR50,App R).Fire Repairs Not Proposed for Sys Required for Hot Shutdown

ML20088A293
Person / Time
Site:	Point Beach
Issue date:	04/04/1984
From:	Fay C WISCONSIN ELECTRIC POWER CO.
To:	Harold Denton, John Miller Office of Nuclear Reactor Regulation
References
TAC-11079, TAC-11080, NUDOCS 8404110354
Download: ML20088A293 (5)

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lMsconsin Electnc mcomu \

231 W. MICHIGAN, P.O. 80X 2046, MILWAUKEE, W153211 0 i I

April 4, 1984 Mr. H. R. Denton, Director Office of Nuclear Reactor Regulation U. S. NUCLEAR REGULATORY COMMISSION Washington, D. C. 20555 Attention: Mr. J. R. Miller, Chief Operating Reactors, Branch 3 Gentlemen:

DOCKET NOS. 50-266 AND 50-301 RE5'PONSE TO 10 CFR 50 APPENDIX _R ALTERNATE SHUTDOWN CAPABILITY POINT BEACH NUCLEAR PLANT, UNITS 1 AND 2 This is in response to a March 26, 1984 request by Mr. T. Colburn of your staff for clarification of our October 26, 1983 submittal which described alternate shutdown capability at Point Beach Nuclear Plant. The Staff's requests and our responses are as follows:

1. Post Fire Repairs The Staff will not accept post fire repairs to systems required for hot shutdown. Provide clarification to show that post fire repairs are proposed only for systems required for cold shutdown.

Clarification No post fire repairs are proposed for systems required for hot shutdown. Post fire repairs are proposed to the residual heat removal (RHR) and component cooling water (CCW) systems which are required for cold shutdown only. The proposed repairs are as follows:

1. Replacement of RHR pump cables.

2. Replacement of CCW pump cables.

3. Replacement of a CCW pump motor.

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Mr.'H.'R. Denton April 4, 1984 2.. Operator Actions The. Staff will.not accept post fire repair activity by the operators to achieve hot shutdown. Provide clarification to show that repair activity is not proposed.-

Clarification The operator actions necessary to achieve hot shutdown are listed in Table 5-1 of our October 26 submittal. Only valve lineup and

-breaker. operations are-required. Table 3-1 includes the disconnection of D.C.. power to ,

prevent spurious operation of certain devices.

This means that the breaker which provides D.C.

power to the device will be tripped OPEN by the ,

operator. We do not propose to physically-disconnect any cables.

3; = Source Range Monitor The licensee proposes to provide either an installed spare rack or a portable monitoring unit. Provide i clarification 1to show that a portable unit will require no more than to be pluggedtinto an available power source.

Clarification We are eval'uating' alternatives for this item:and have not' developed a fina11 design' . If the decision i:s made to use a portable monitor, it will' be equipped with a plug and a proper receptacle will be.provided.

a4 . Zone 17 Cable Separation The licensee proposes alternate shutdown-capability-for-redundant instrument cables :b1 the-zone. : Provide clarification to show how redundant hot shutdown system cables :bi the' zone:arenprotected'in accordance with Section.III.G.2.

Clarification-Thefonly redundant cables:for.a hot shutdown system

.which are-located in. Zone 7~are the normal control These cables.

cables-for the CVCS charging ~ pumps.

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.Mr. H. R. Denton_ April 4, 1984 can.be isolated at the alternate shutdown panels located in the charging pump area.

Therefore, alternate shutdown capability for charging pump operation is provided.

5. High-Low Pressure Interface The Staff is concerned about high-low pressure interfaces. Provide clarification to show which of the components listed in Table 3-1 are high-low pressure interfaces.

Clarification The high-low pressure interface components listed in Table 3-1 for which spurious actuation is credible and their system function are listed below.

1,2-V200A Letdown isolation valve 1,2-V200B Letdown isolation valve 1,2-V200C Letdown isolation valve 1-MOV-1299 Excess letdown isolation valve 2-MOV-1299 Excess letdown isolation valve 1-MOV-700 RCS-RHR isolation valve 1-MOV-701 RCS-RHR isolation valve 2-MOV-700 RCS-RHR isolation valve MOV-701 RCS-RHR isolation valve 1-PCV-430 Pressurizer PORV l-PCV-431C Pressurizer PORV 2-PCV-430 Pressurizer PORV 2-PCV-431C Pressurizer PORV 1,2-RC570A Reactor vessel head vent isolation valve 1,2-RC570B. Reactor vessel head vent isolation valve

1,2-RC580A- Pressurizer head vent isolation valve

-1,2-RC580B Pressurizer head vent isolation valve 1,2-RC575A Head vent system isolation valve 1,2-RC575B Head vent system isolation L.

valve 1-MOV-598 RCS drain isolation valve 1-MOV-599 RCS drain isolation valve 2-MOV-598 RCS drain isolation valve 2-MOV-599 RCS drain isolation valve

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l Mr. H. R. Denton April 4, 1984

6. Excess Letdown Isolation Valve Provide clarifications which explain th< operation of the proposed fire safe relay modification.

Clarification The normally deenergized fire safe relay (FSR) would be installed in parallel with the valve opening coil with normally closed contacts in the valve opening circuit. A hot short between the control switch and the FSR circuit would energize the FSR, open its contacts in the valve opening circuit, and prevent spurious valve operation. However, in the event of a hot short between the energizing contacts and the opening circuit contacts of the FSR, actuation of the FSR prior to the MOV opening coil cannot be assured.

Therefore, we propose to modify the excess letdown valve control circuits on each unit so that a minimum of two separate shorts in two separate sets of cable would be required for spurious valve operation. One short would have to occur between a specific non-energized conductor and a conductor within the same cable or another cable which is energized at 120 VAC with respect to plant ground. A second short would also be necessary between a specific conductor and plant ground either directly or by short to another grounded wire. The occurrence of specific double shorts is not considered to be a credible event.

The double break protection modification is shown on'the attached Figure 4-9A.

Should you have questions regarding these clarifications, please contact us.

Very truly yours, V/

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Vice President-Nuclear Power C. W. Fay Attachment Copy.to NRC Resident Inspector j

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cost FIG. 4-9 A DOUBLE BREAK CIRCUlT MODIFICATION FOR EXCESS LETDOWN ISOLATION VALVES (1,2 MOV 1299)

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