ML20197K127

Forwards Info on ECCS & Emergency Feedwater Sys,In Response to Items E & F of IE Bulletin 85-003, Motor-Operated Valve Common Mode Failures During Plant Transients Due to Improper Switch Settings

ML20197K127
Person / Time
Site:	Yankee Rowe
Issue date:	05/14/1986
From:	Heider L YANKEE ATOMIC ELECTRIC CO.
To:	Murley T NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
DCC-86-051, DCC-86-51, FYR-86-050, FYR-86-50, IEB-85-003, IEB-85-3, NUDOCS 8605200266
Download: ML20197K127 (7)

Text

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Te'ephone (6 ") *' - 'oo YANKEE ATOMIC ELECTRIC COMPANY TWX 710-380-7619

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1671 Worcester Road Framingham, f.fassachusetts 01701 DCC 66-051

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May 14, 1986 FYR 86-050 United States Nuclear Regulatory Commission Region I 631 Park Avenue King of Prussia, PA 19406 Attention: Dr. Thomas E. Murley Regional Administrator

References:

(a) License No. DPR-3 (Docket No. 50-29)

(b) Yankee Nuclear Power Station, " Final Safety Analysis Report," Volume 1 Sections 212 and 220, dated July 1985 (c) IE Bulletin No. 85-03, " Motor-operated Valve Common Mode Failures During Plant Transients Due to Improper Switch Settings," dated November 15, 1985 Subj ect.: IE Bulletin No. 85-03, items e and f

Dear Sir:

In accordance with the requirements outlined in Items e and f of IE Bulletin No. 85-03 (Reference (c)), we hereby submit the following two attachments.

If you have any questions regarding this submittal, please contact us.

Very truly yours, YANKEE ATOMIC ELECTRIC COMPANY d W L. ileider Vice President and Manager of Operations GP/no Attachments COMMONWEALTH OF MASSACHUSETTS)

)ss MIDDLESEX COUNTY )

Then personally appeared before me, L. H. Heider, who, being duly sworn, did state that he is Vice President and Manager of Operations of Yankee Atomic Electric Company, that he is duly authorized to execute and flle the foregoing document in the name and on the behalf of Yankee Atomic Electric Company and that the statements therein are true to the est of his knowledge nd belief.

/ w # tat "Krinand R. Soucy Notary P h My Commission Expires August 29, 1991 8605200266 860514 Ml PDR ADOCK 05000029 pII G PDR , ,

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ATTACHMENT A 4n ,

Emergency Core Coolina System (ECCS)

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Each of the LPSI and NPSI pumps and aasociated valves are dedicated for the ECCS Only. A dedicated ECCS, along' with the primary system being isolated from the ECCS by check valves, o'nlycallows the ECCS to be prealigned such that no Motor-Operated Valves -(MOVs) are required to operate on a Safety Injection ActuationSidnal(SIAS). Per the YNPS Technical Specifications, all MOVs are aligned such.that no MOVs are.requirdt g to operate following a SIAS.

The YNPS HPSI System includes the safety injection tank with its associated piping land valves to the HPSI and LPSI pumps, LPSI pump discharge piping and valve's to the HPSI pumps. the HPS1 andjLPSI pumps themselves, and the HPSI puttps discharge' piping up to' the Main Coolant System. The HPSI System does C ,

not include the LPSI header piping, the safety injection accumulator (part of LPSI), or the Vapor'Cpatainer (VC) Sump Recirculation System (including hot lag injection).

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1 A failure of the Maih Coolant System pressure boundary and its attendant loss of coolant or a major steam line break with its accompanying rapid cooldown of the Main Coolant System results in a system depressurization and the

-* initiation of a SIAS. SIAS stsets each train of HPSI and LPSI pumps simultaneously. The-LPSI'puups discharge to the LPEI header and through a crossover to the suctlon of the KPSI pumps. The HPSI pumps discharge to the HPSI header. The HPSI and LPSI di'scharge piping are separated up to a point adjacent to each main coolant loop, where the two lines join together downstream of a check valve in each line and enter the cold leg through the same nozzle. Each leg of the HPSI hdader incorporates a throttle valve to maintain header' pressure and ensure injection to the intact loops in the event of a break in one of the injection lines. Suction continues from the safety injection tank until a prescribed level is reached. Again, no MOVs are required to operate to establish HPSI flow. With the decrease in Main Coolant System pressure on the downstream side of the ECCS check valves to a value less than the design head of the HPSI/LPSI pumps on the upstream side of the ECCS check valves, HPSI System flow is established. Additional information on the HPSI System is available in Reference (b).

Table No. 1, "ECCS Motor-Operated Valves," is a listing of not only all HPSI MOVs in question but of all ECCS MOVs. Also indicated is their normal and HPSI System functional posi,tions. From Table No. 1, the following may be readily ascertained: ,

, 1. The normal position for not only all HPSI System MOVs, but for all ECCS i MOVs as compared to their required position for HPSI System flow is one and the same, i.e., no valvo' operation is required to institute HPSI Syst'em flow. '

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f ATTACHMENT A (Continued)

Dedicated Emergency Core Cooling System (ECCS)

2. All HPSI System flow path valves have two control switches, one of which is key-locked to prevent inadvertent operation of the valves and to assure Technical Specification compliance of valve positions.

3. HPSI MOVs, i.e, MOVs in the earlier described HPSI flow path, are indicated by Remark No. 1 under the remarks column (total nine MOVs)

Since no MOVs are required to operate to establish HPSI System flow, the inherent simplicity exhibited by the YNPS dedicated ECCS results in a HPSI System which requires no MOVs "... to be tested for operational readiness in accordance with 10CFR50.55a(g) ..." Table No.1 is provided for information only; no MOVs have been identified in the HPSI System which would require reporting per IE Bulletin No. 85-03. Therefore, no further action is required to be taken for IE Bulletin No. 85-03 in regards to the HPSI System.

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TABLE No. 1 ECCS Motor-Operated Valves ECCS Normal HPSI Valve No. ECCS Function Position Position Remarks HPSI Syctern CS-MOV-536 Loop 1 HPSI Dsch Viv Open Open 1, 2 CS-MOV-537 Loop 2 HPSI Dsch Viv Open Open 1, 2 CS-MOV-538 Loop 3 HPSI Dsch Viv Open Open 1, 2 CS-MOV-539 Loop 4 HPSI Dsch Viv Open Open 1, 2 SI-MOV-4 LPSI/HPSI Xover Viv Open Open 1, 2 SI-MOV-46 HPSI Hde Dsch Viv Open Open 1, 2 , 3 SI-MOV-48 SIT /HPSI/LPSI Recire Vlv Open Open 1,2,3 SI-MOV-49 SIT /HPSI/LPSI Recire Viv Open Open 1,2,3 SI-MOV-518 SIT /Dsch Viv Open Open 1,2,3 LPSI System SI-MOV-22 Loop 4 LPSI Dsch Viv Open Open 4 SI-MOV-23 Loop 3 LPSI Dsch Viv Open Open 4 SI-MOV-24 Loop 2 LPSI Dsch Viv Open Open 4 SI-MOV-25 Loop 1 LPSI Dsch Viv Open Open 4 CS-MOV-533 LPSI Hde Dsch Viv Open Open 2, 3 CS-MOV-534 No Function Close Close 5 CS-MOV-535 LPSI Hdr Dsch Viv Open Open 2, 3 SI-MOV-516 VC Sump Viv Close close 2, 6 SI-MOV-517 VC Sump Viv Close close 2, 6 SI-MOV-1 SI Accum Viv Open Open 2 SI-MOV-514 Hot Leg Inj Viv Close Close 2, 6 SI-MOV-515 Hot Leg Inj Vlv Close Close 2, 6 CS-MOV-532 LPSI Recire Viv Close Close 2, 7 CS-MOV-524 Hot Leg Inj/Chrg Viv Open Open 8 REMARKS

1. HPSI flow path motor-operated valve.

2. Two control switches, one key-locked.

3. Closes for recirculation / hot leg injection mode of ECCS.

4. Circuit breakers removed.

5. Power cables disconnected at motor starter.

6. Opens for recirculation / hot leg injection mode of ECCS.

7. Open 30 minutes / week maximum for LPSI pump testing / SIT mixing.

8. Hot leg injection mode of ECCS.

4 ATTACHMENT B Emergency Feedwater System Analogous to the HPSI System (Attachment A), the YNPS Emergency Feedwater System exhibits the same simplicity of design and operation. That is, the Emergency Feedwater System is a dedicated system prealigned to serve its intended function with secondary system pressure boundary isolation being provided by in-line check valves. No Motor-operated Valves (MOVs) are required to be operated to establish Emergency Feedwater System flow.

The YNPS Emergency Feedwater System includes the primary water storage tank, suction piping to the two motor-driven emergency boiler feed pumps, and discharge piping to the Boiler Feed System. Also part of the Emergency Feedwater System is a second path which includes the demineralized water storage tank suction piping to the turbine-driven emergency boiler feed pump, the turbine-driven emergency boiler feed pump, and discharge piping which joins to the same piping utilized by the motor-driven emergency boiler feed pumps to the Boiler Feed System.

One turbine-driven pump and two motor-driven pumps are available for supplying emergency feedwater to the steam generators. The two motor-driven pumps take a suction from the primary water storage tank and have the demineralized water storage tank available as a backup. Each pump is capable of discharging to the steam generator side of the four motor-operated isolation valves in the feedwater supply piping. The two motor-driven pumps are capable of being operated from the Control Room or locally. All emergency feedwater pumps are manually started by the operators; there is no autostart feature.

Under the condition of total loss of ac power to the station, feed to the steam generators is provided by the steam turbine-driven triplex pump located in the Auxiliary Boiler Room. Pump suction is from the demineralized water storage tank with the primary water storage tank as a backup. The turbine-driven pump is capable of discharging to the steam generator feedwater piping through the same piping as_the motor-driven pumps. This pump is operated locally. Steam for the turbine is taken from a separate branch line off Main Steam Line Nos. 2 and 3 through a pressure-reducing station in the Auxiliary Boiler Room. When nuclear steam is not available during plant shutdown, steam can be supplied from the building heat steam line. Again, no MOVs are required to operate to institute Emergency Feedwater System flow, only pump starts. In fact, the turbine-driven side of Emergency Feedwater System has no MOVs at all, only check valves and manual valves. Additional information on the Emergency Feedwater System is available in Reference (b).

Table No. 2. " Emergency Feedwater System Motor-Operated Valves," is a listing of all Emergency Feedwater System MOVs, along with their normal and functional position. .

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. ATTACHMENT B (Continued)

Emergency Feedwater System From Table No. 2 the following may be readily ascertained:

1. The normal and operational position of all Emergency Feedwater System MOVs is one and the same, i.e., no valve operation is required to institute Emergency Feedwater System flow.

2. No MOVs are in line with the turbine-driven pump portion of-the Emergency Feedwater System, i.e., the discharge piping from the turbine-driven pump to the Boiler Feed System contains only check valves and manual valves.

As with the HPSI System, since no MOVs are required to operate to establish Emergency Feedwater System flow, the Emergency Feedwater System requires no MOVs "... to be tested for operational readiness in accordance with 10CFR50.55a(g) ..." Table No. 2 is provided for information only. No MOVs have been identified in the Emergency Feedwater System which would require reporting per IE Bulletin No. 85-03. Therefore, no further action is required to be taken for IE Bulletin No. 85-03 in regards to the Emergency Feedwater System.

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TABLE NO. 2 Emergency Feedwater System Motor-Operated Valves Emergency Feedwater Normal System Valve No. Function Position Position Remarks EBF-MOV-555 Motor-Driven Emergency Open Open 1 Fdwtr Pumps Dsch Viv EBF-MOV-556 Motor-Driven Emergency Open Open 1 Fdwtr Pumps Kover Viv EBF-MOV-557 Motor-Driven Emergency Close Close 2 Fdwtr Pumps Alt Stm Gen Fdwtr Sys Dsch Viv REMARKS

1. Emergency Feedwater System MOV.

2. Pressure boundary isolation valve between Emergency Feedwater System and Alternate Steam Generator Feedwater System not in Emergency Feedwater System flow path.

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