ML18151A057

LER 87-002-00:on 870104,three Control/Relay Room Chillers Tripped on High Condenser Discharge Pressure.Caused by Insufficient Svc Water Flow to Condenser of Chiller Unit. Valve Lineup to & from Chiller checked.W/870917 Ltr

ML18151A057
Person / Time
Site:	Surry
Issue date:	09/17/1987
From:	Benson D VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
87-024, 87-24, LER-87-002-02, LER-87-2-2, NUDOCS 8709240517
Download: ML18151A057 (4)

Text

POW 28-06-01 NRC Form 366 U.S. NUCLEAR REGULATORY COMMISSION (9-83)

APPROVED 0MB. NO. 3160-0104 EXPIRES: B/31/88 LICENSEE EVENT REPORT (LER')

• ./

FACILIT'I' NAME (1) DOCKET NUMBER (2) PAGE l3J TITLE (4)

Surry Power Station, Unit 1 !o 15 Io Io Io 12 18 IO 1 loF O I 3 Control /Relay Room Chiller Tripped Due To Inadequate Service Water Flow EVENT DATE '15) LER NUMBER (6) REPORT DATE (7) ,OTHER FACILITIES INVOLVED (Bl MONTH DAY YEAfl YEAR FACl:Ll:Y-Y NAMES DOCKET NUMB!:R(S) o 11 oI 4 8 1 8J1- op 12 - o I o OI 9 11 7 s 17 OPERATING N THIS REPORT IS SUBMITT£D Pl:IRSUANT TO THE R£QUIR£MENTS OF 10 CFR §: (t:htJClc on* or mar* of th* fol/o,ying) *.(1,1)

MODE 18) 20.402(b)

-- 20.406(c)

- 60.73(all2)(iv)

- 73.71(b)

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&0.731all2)(1) 50.721a112lM 50.73(a)12)(vll)

&0.73(a)(2)CYlll)(A)

-- 73.71(c)

OTHER (Spoclfy in Ab1tr*ct b*low *nd In T*xt, NRC Form 366A)

- &0.73(1)(2)(ii)

&0.73(1)(2)(1U)

- &0.73(all2llvlilltB) 60.73(1)(2)hd LICENSEE CONTACT FOR THIS LER (121 NAME TELEPHONE NUMBER AREA CODE D. L. Benson, Station Manager 81 0 14 31 5 17 I -1 3 11 I 814 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT 113)

CAUSE SYSTEM COMPONENT MANUFAC- MANUFAC-TURER SYSTEM COMPONENT TURER I I I I I I I I I I I I I I I I I I I I I I I I I. I I I SUPPLEMENTAL REPORT EXPECTED (141 MONTH DAY YEAR

• EXPECTED

.n YES (If yes, compl*t* EXPECTED SUBMISSION DA TE)

ABSTRACT (Limit to 1400 spoc*s, i.*.. opproxim*toly flfto*n singl*-spoc* rypowrltton lines) (18)

SUBMISSION DATE 115)

I I I On January 4, 1987 at 0610 hours0.00706 days <br />0.169 hours <br />0.00101 weeks <br />2.32105e-4 months <br />, one of the three control room/

relay room chillers (1-VS-E-4C) {EIIS-CHU} tripped on high condenser discharge pressure. The 'A' chiller unit had pre-viously been removed from service for maintenance. This is contrary to Technical Specification 3.14 which requires one control/relay chiller to be operating and another to be operable.

The 'C' chiller was returned to service at 0730 hours0.00845 days <br />0.203 hours <br />0.00121 weeks <br />2.77765e-4 months <br />. At the time of these events, both Units 1 and 2 were at cold shutdown.

The cause of the event was insufficient service water (SW)

{EIIS-BI} flow to the condenser of the control room/relay room chiller unit. It is believed that the manual service water dis-charge isolation valve was partially obstructed. The valve was cycled several times, cooling flow was reestablished and the chiller was returned to service at 0730 hours0.00845 days <br />0.203 hours <br />0.00121 weeks <br />2.77765e-4 months <br />. Service water pressure to the control/relay room chillers is* checked every four hours; and the SW strainers are cleaned whenever SW pressure becomes low. The control/relay room ventilation system is being evaluated by Engineering, and plans are being developed to upgrade the system. The rotating SW strainer has been re-placed.

8709240517 870917 Tt: l'2-PDR ADOCK 05000280 S PDR 1 !*

. I NRC Form 3t.

(9-83)

POW 28-06-01 e e U.S. NUCLEAR REGULATORY COMMISSION NRC Form 366A 19-831 LICENSEE EVENT REPORT (LERI TEXT CONTINUATION APPROVED OM8 NO. 3150-0104 EXPIRES: 8/31 /88 FACILl'fY NAME 111 DOCKET NUMBER (2) LER NUMBER 161 PAGE (3)

Surry Power Station,_ Unit 1 0 .1 s IO IO IO I2 18 IO 8 17 - 0 I d 2 - a O OI 2 OF ol 3 TEXT 1/f,,,,,,. _ia-,und, u* tHJdltioMINRC Fonnll!ii!A'*i 1171 1.0 Description of the Event On January 4, 1987 at 0610 hours0.00706 days <br />0.169 hours <br />0.00101 weeks <br />2.32105e-4 months <br />, one of the three control room/relay room chillers (1-VS-E-4C) {EIIS-CHU}

tripped on high condenser discharge* pressure. The 'A' chiller unit had previously been removed from service for maintenance. This is contrary to Technical Specification 3.14 which requires one control/relay chiller to be operating and another to be operable.

The 'C' chiller was returned to service at 0730 hours0.00845 days <br />0.203 hours <br />0.00121 weeks <br />2.77765e-4 months <br />.

At the time of these events, both Units 1 and 2 were at cold shutdown.

2 ..0 Safety Consequences and Implications The control/relay room air conditioning system consists of three 100% capacity air conditioning chiller units.

The design temperature of the control and relay room spaces is from 40 dgrees Fahrenheit to 100 degrees Fahrenheit and the electrical equipment has been qualified at 120 degrees Fahrenheit ambient temperature.

During this event, the control/relay room air han4ling units remained operable or operating .. Additionally, there was no noticeable increase in ambient temperature of tqe control or relay room areas. Therefore, this event did not create an unreviewed safety question and the health and safety of the public were not affected.

3.0 Cause The cause of the event was insufficient service water (SW) {EIIS-BI} flow to the condenser of the control room/relay room chiller unit. It is believed that-the manual service water discharge isolation valve was partially obstructed.

4.0 Immediate Corrective Action The valve lineup to and from the inoperable chiller was checked and SW was verified to be available for the chiller condenser SW pump. No SW temperature difference was observed across the condenser unit and it was determined that there was no cooling flow.

NRC FORM 366A

• U.S.GPO: 1986-0-624-536/455 19-831

POW 28-06-01 e e NRC Farm 366A U.S. NUCLEAR REGULATORY COMMISSION 19-831 LICENSEE EVENT REPORT (LER) TEXT CONTINUATION APPROVED 0MB NO. 3150-0104 EXPIRES: 8/31/88 FACILIT'f NAME 111 DOCKET NUMBER 121 LER NUMBER 161 PAGE 131 Surry Power Station, Unit 1 a 1s I a I a I o 12 1 a1o a 11 - o ro 1 2 - 01 o or 3 oF o 13 TEXT /If mota ,,_,. ia ,.,,und, UN - NRC Form 365A '1/ 1171 The manual discharge isolation valve was cycled several times and cooling flow was returned. The chiller was returned to service with no further problems.

5.0 Additional Corrective Action Service water pressure to the control/relay room chillers is checked every four hours; and the SW strainers are cleaned whenever SW pressure becomes low.

6.0 Actions Taken to Prevent Recurrence The control/relay room ventilation system is being evaluated by Engineering, and plans are being developed to upgrade the system. The rotating SW strainer has been replaced.

7.0 Similar Events Unit 1 LER 86-024 Unit 1 LER 86-027 Unit 1 LER 86-030 Unit 1 LER 86-031 8.0 Manufacturer/Model Number N/A NRC FORM 366A

• U.S.GPO: 1986*0-624-538/455 19-831

e VIRGINIA ELECTRIC AND POWER COMPANY Surry Power Station P. 0. Box 315 Surry, Virginia 23883 September 17, 1987 U.S. Nuclear Regulatory CODDD.ission Serial No.: 87-024 Document Control Desk Docket No.: 50-280 016 Phillips Building Licensee No.: DPR-32*

Washington, D.C. 20555 Gentlemen:

Pursuant to Surry Power Station Technical Specifications, Virginia Electric and Power Company hereby submits the following Licensee Event Report for Surry Unit 1.

.REPORT NUMBER 87-002-00 This report has been reviewed by the Station Nuclear Safety and Operating Committee and will be reviewed by Safety Evaluation and Control. The report

• was prepared within the thirty day time requirement, but due to administra-tive error, it was never submitted to SNSOC. Consequently, this report is being forwarded at* this.time.

• Very truly yours, David L. Benson Station Manager Enclosure cc: Dr. J. Nelson Grace Regional Administrator Suite 2900 101 Marietta Street, NW Atlanta, Georgia 30323

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