ML17334A412

Submits Update Re Compliance W/Items II.E.4.2 & II.F.1 of NUREG-0737.Design Mod Initiated to Replace Existing NESW CIVs w/air-operated Valves of Superior Leak Tightness & Corrosion Resistance Characteristics

ML17334A412
Person / Time
Site:	Cook
Issue date:	07/09/1982
From:	Hunter R INDIANA MICHIGAN POWER CO. (FORMERLY INDIANA & MICHIG
To:	Harold Denton Office of Nuclear Reactor Regulation
References
RTR-NUREG-0737, RTR-NUREG-737, TASK-2.E.4.2, TASK-2.F.1, TASK-TM AEP:NRC:0702, AEP:NRC:702, NUDOCS 8207160091
Download: ML17334A412 (5)

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REGULATORY INFORMATION DISTRIBUTION 'SYSTEM (R IDS)

'AOCE'8 SION NBR 82071 6009 1 DOC ~ DATE 82/07/09 NOTARIZED NO DOCKET FACIL:50 BYNAME 315 Donald', Cook Nuclear Power Planti Unit 1< Indiana 8 05000315 50-316 Donald C ~ Coom Nuclear Power Plant< Unf t 2< Inoiana R 05000316 AU1H AUTHOR AFFILIATION HLNTERgR ~ ST Indiana 8 Michigan Electric Co ~

R E<C I P ~ NAME RECIPIENT AFFILIATION OE.NTONr H, ~ R 0 Office of Nuclear Reactor Regulation~ Director SLBJECT! Submi:ts- update re compliance w/items II.E.4,2 8 II of NUReg<<0737.Design mod initiated to replace existing

'. 1 hESN CIVs w/air -operateo valves of superior leak tightness corrosion resistance characteristics.

DISTRISUTIOt'ODE: AOSSS COPIES RECEIVED:LTD L ESCL J SIZE:

TITLE: Response to NUREG -0737/NUREG-0660 TMI Action Plan Rgmts (OL's)

NGTES:

RECIPIENT COPIES RECIPIENT COPIES ILr CODE/NAvE L.T TR ENCL ID CODE/b.at E LTTR ENCL ORB ei BC 01 7 7 INTERVAL: ELO/HDS3 0 IE/DEP D IR 33 1 1 IE/DEP EPOS 1 IE/DEP/EPLB 3 NRR/DE OIR 21 1 1 NRR/DE/AOCSE 22 1 1 NRR/DE/ADl'GE 23 1 1 NRR/OHFS DIR 28 1 1 NRR/DHFS/DEPY29 1 1 NRR/OL DIR 1 NRR/DL/AOL 16 1 1 NRR/DL/ADOR 15 1 1 NRH/DL/ADSA 17 1 1 NRR/DL/GRAB 18 3 3 NRR/DSI DIR 24 1 1 NRR/DSI/ADOPS25 1 1 NRR/DSI/ADRP 26 1 1 NRR/DS I/AORS 27 1 NRR/OS I/AEB 1 NRR/DS I/ETSB 1 1 NRR/OS I/RAB 1 1 NRR/DST D IR 30 1 1 NRR/OST/AOGP 31 1 1 NRR/DST/AOT 32 1 1 REG F ILE 04 1 1 RGN3 1 1 EXTERhAL: ACRS 34 10 10 FEMA-REP OI V 1 1 I.NPO/J ~ STARNES 1 1 LPOR 03 2 2 NRC PDR 02 1 1 NSIC 05 1 1 NTIS 1 TOTAL NUMBER OF COPIES REQUIRED: L'TTR,54 ENCL 53

INDIANA 1 MICHIGAN ELECTRIC COMPANY P. O. 8OX 18 BOWLING GREEN STATlON HEW YORK ~ Ho Y 10004 July 9, 1982 AEP:NRC:0702 Donald C. Cook Nuclear Plant Unit Nos. 1 and 2 Docket Nos. 50-315 and 50-316 License Nos. DPR-58 and DPR>>74 NUREG-0737 Item II.E.4.2 and Item II.F.1, Attachment 6 Mr. Harold R. Denton, Director Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Washington, D.C. 20555

References:

(1) Letter AEP:NRC:0253 dated October 24, 1979 (2) Letter AEP:NRC:0334B dated March 10, 1980 The reference letters provided information to the Staff regarding the Cook Plant's compliance with various requirements contained in NUREG-0737. At the time of the above referenced submittals, our responses concerning Item II.E.4.2, "Containment Isolation Depend-ability", correctly stated that each containment isolation valve (CIV) in the Cook Plant was controlled by its own control switch. However, subsequent to planned modifications, the Non-Essential Service Water System (NESW) and the Post-Accident Containment Hydrogen Monitoring System (PACHMS) will use one switch to control more than one CIV. We have re-reviewed the criteria set-forth in NUREG-0737 and, for reasons summarized below, have concluded that the use of one switch to control more than one CIV in the NESW and PACHM systems is acceptable. This letter is being submitted in order to update the record with regard to our compliance with Item II.E.4.2 of NUREG-0737.

A design modification has been initiated to replace the existing NESW CIVs (56 valves per Unit) with air-operated valves of superior leak tightness and corrosion resistance characteristics. Fourteen of the valves being replaced are check valves. Thus, the scope of the design modification includes providing controls for an additional fourteen air-operated valves.

This design modification, which we plan to implement during the 1982 refueling outage for each"Unit of the Cook Plant, represents our corrective action to the difficulties experienced with 10 CFR 50 Appendix J leak rate testing of certain valves. Upon completion of the design modifications, two train oriented, airoperated CIVs will be 8207160091 820709 PDR *DOCK 05000315 P PDR

provided in-series on each NESW supply and return line to and from the containment.

The control switches for the existing forty-two (42) air-operated NESW CIVs are located on the IV panel in the main control room. The IV panel, the panels on either side immediately adjacent to the IV panel and the NESW system panel contain insufficient space for the additional switches. Therefore, the decision was made to control two CIVs from the same switch. Although one switch does control more than one valve, no flow path (supply or return line) can be opened by a single switch. We believe that the operation of more than one CIV with a single control switch in the manner described above is acceptable and does not violate the requirements of Item II.E.4.2 of NUREG-0737.

The PACHMS is being installed in fulfillment of the requirements of Item II.F.l, Attachment 6, of NUREG-0737. Each of the two redundant trains of the PACHMS is a closed loop system designed to Seismic Class I standards and is capable of withstanding exposure to containment design pressure.

The PACHMS, which is described in our AEP:NRC:0631 letter dated January 11, 1982 (*), utilizes nine sampling lines, each with two in-series CIVs. Four sampling lines are associated with the Train analyzer and five sampling lines are associated with the Train 'A'ydrogen

'B'ydrogen analyzer. Such an arrangement assures that failure of a single electrical train would not result in closure of all PACHMS CIVs with a resultant loss of hydrogen monitoring capability. PACHMS operation requires that the two air-operated CIVs in each sample inlet line and the air operated CIV in the return line be opened at the same time. The control switches for the PACHMS are of the spring return type to prevent inadvertent valve opening and for the operator to obtain a sample, three valve control switches would have to be held in the open position simultaneously. Therefore, one switch was chosen to operate both the two CIVs on the sampling inlet line and the CIV in the return line. It should be noted that, prior to reset of the containment isolation signal each PACHMS CIV is capable of being tripped on a containment isolation signal from either a Train 'A'r a Train isolation signal. In addition, the PACHMS CIVs are designed

'B'ontainment to fail closed on loss of air and further, failure of the control circuits would also normally cause the valve to close. However, since the PACHMS is fully capable of withstanding exposure to containment design pressure, the hypothetical failure of the PACHMS CIVs to close would not constitute a threat to containment integrity. Based on the above considerations, we have concluded that operation of more than one PACHMS CIV with a single control switch is acceptable.

(*) Due to a typographical error the letter was dated January ll, 1981.

Mr. Harold R. Denton 4 AEP:NRC:0702 This document has been prepared following Corporate Procedures which incorporate a reasonable set of controls to insure its accuracy and completeness prior to signature by the undersigned.

Very truly yours, R. S. Hunter Vice President

/md cc: John E. Dolan - Columbus R. W. Jurgensen W. G. Smith, Jr. Bridgman R. C. Callen G. Charnoff Joe Williams, Jr.

NRC Resident Inspector at Cook Plant Bridgman

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