ML18151A053

LER 87-021-00:on 870818,control/relay Room Chiller 1-VS-E-4B Tripped on High Condenser Discharge Pressure.Caused by Inadequate Svc Water Flow Due to Buildup of Seaweed in Y-type Suction Strainers.Strainers cleaned.W/870911 Ltr

ML18151A053
Person / Time
Site:	Surry
Issue date:	09/11/1987
From:	BENSON D L VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
87-023, 87-23, LER-87-021, LER-87-21, NUDOCS 8709160296
Download: ML18151A053 (4)

Text

,, NRC Form ,366 (9-83) FACILITY NAME (11 TITLE (41 LICENSEE EVENT REPORT CLER) Surrv Power Station. Unit 1 POW 28-06-01 U.S. NUCLEAR REGULATORY COMMISSION APPROVED 0MB NO. 3160-0104 EXPIRES: 11/31/88 I DOCKET NUMBER (21 I P*"'E (31 O I 5 I O I O I O 12 I. 8 I O 1 I OF O I 3 Control /Relay Room Chillers Tripped Due To Inadequate Service Water Flow EVENT DATE (51 LER NUMBER (61 REPORT DATE (71 OTHER FACILITIES INVOLVED (Bl MONTH DAY . YEAR YEAR :)t tr MONTH DAY YEAR FACILITY NAMES DOCKET NUMBER(SI OPERATING MODE (91 .. ">.' ' ' O 1 5 j O . I O I O I I I THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Chock one or mar* of tho follo"(ln11}

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&0,73(111211*1 LICENSEE CONTACT FOR THIS LEA (121

• NAME TELEPHONE NUMBER AREA CODE D. L. Benson, Station Manager 810 1--4 3 15 I 71-13 I 1 18 14 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT 1131 CAUSE SYSTEM COMPONENT TURER I I I I I I I !i!!ii!ll!!!!!i!!!!!i!i!!!i!i!i!i!!illilllilllli!illi I I I I. I I I I I I I I I I :i!i!l!l!l!l!l!l!i!llllllll!ll!lllllli!lli!lllli!!!!!

I I I I I I I l!l!l!illll!lllli!lll!lllllllllllllllliiiliiililiii SUPPlEMENTAL REPORT EXPECTED (141 MONTH DAY YEAR n YES (If yes, complete EXPECTED SUBMISSION DATE} I-xi NO EXPECTED SUBMISSION DATE 1161 I I I ABSTRACT (Limit to 1400 ,paces, i.* .* *pproxim*tely fiftHn 1/n11le-11Mce typewritten line1/ (161 NRC Form 368 (9-831 On August 18, 1987 at 1139 hours0.0132 days <br />0.316 hours <br />0.00188 weeks <br />4.333895e-4 months <br />, one of the three control/ relay room chillers (1-VS-E-4B)

{EIIS-CHU}

tripped on high condenser discharge pressure.

The 'A' chiller unit had previously been removed from service in order to clean its service water (SW) suction strainer.

At 1142 hours0.0132 days <br />0.317 hours <br />0.00189 weeks <br />4.34531e-4 months <br />, the 'C' chiller was declared inoperable when its freon relief valve lifted. This is contrary to Technical Specification 3.14 which requires one control/relay room chi1ler-*:;;t6_*be

• operating and another to be operable.

The 'A' chiller was returned to service at 1143 hours0.0132 days <br />0.318 hours <br />0.00189 weeks <br />4.349115e-4 months <br /> and the 'B' chiller was returned to service at 1300 hours0.015 days <br />0.361 hours <br />0.00215 weeks <br />4.9465e-4 months <br />. At the time of these events, both Units 1 and 2 were at 100% power. The cause of this event was insufficient SW flow.to the condenser of the chiller units due to a buildup of seaweed in the y.:..type suction strainers. -The SW-strainers were cleared of debris. 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 "1 strainer has been replaced.

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Y \/ \ 8709160 PDR AD5tfr 870911 s "osooo2a 0 PDR NRC Form 31111A 19-831

• FACILITY NAME 111 e e LICENSEE EVENT REPORT (LER) TEXT CONTINU~TION POW 28-06-01 U.S. NUCLEAR REGULATOR_Y COMMISSION APPROVED 0MB NO. 3150--0104 EXPIRES: 8/31 /88 DOCKET NUMBER 121 LEA NUMBER 1111 PAGE 131 Surry Power Station, Unit 1 o Is I o I o I o I 2 18 b 8 17 -O I 2 I 1 -o In n I? OF nl TEXT (If,,_ -* ,.,,,..,, uw NRC Fomt3116A'*J 1171 NRC FO .. M 386A Ul-831 1.0 Description of the Event On August 18,.1987 at 1139 hours0.0132 days <br />0.316 hours <br />0.00188 weeks <br />4.333895e-4 months <br />, one of the three control/relay room chillers (1-VS-E-4B)

{EIIS-CHU}

tripped on high condenser discharge pressure.

The 'A' chiller unit had previously been removed from service in cider to clean its service water (SW) suction strainer.

At 1142 hours0.0132 days <br />0.317 hours <br />0.00189 weeks <br />4.34531e-4 months <br />, the 'C' chiller was declared inoperable when its freon relief valve lifted. This is contrary to Technical Specification 3.14 which requires one control/relay room chiller to be operating and another to be operable.

The 1 A' chiller was returned to service at 1143 hours0.0132 days <br />0.318 hours <br />0.00189 weeks <br />4.349115e-4 months <br /> and the 'Bi chiller was returned to service at 1300 hours0.015 days <br />0.361 hours <br />0.00215 weeks <br />4.9465e-4 months <br />. At the time of the~e events, both Units 1 and 2 were at 100% power. 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 degrees 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 handling units remained operable or operating.

Additionally, there was no noticeable increase in ambient temperature of the 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 control/relay room chillers tripped and/or had a freon relief valve lift due to high condenser discharge pressure resulting from low SW flow. The low SW flow was due to a buildup of seaweed in the upstream SW Y-Type strainers

{EIIS-STR}.

A contributing factor was that a rotating strainer in the SW system was scheduled for replacement and had been removed from service. .u.s.GPO:

111&11-0-824-638/465

.. NRC Form 366A 19-831 FACILITY NAME 11) e e LICENSEE EVENT REPORT (LER) TEXT CONTINUATION POW 28-06-01 U.S. NUCLEAR REGULATORY COMMISSION APPROVED DMB ND. 3150-0104 EXPIRES: 8/31 /88 DOCKET NUMBER (2) LER NUMBER (6) PAGE 13) Surry Power Station, Unit 1 NRC FORM 366.A 19-831 0 I 5 I O I O I O 12 I 81 0 8 I 7 -0 I 21 1 -0 I O ol 3 OF O 13 4.0 Immediate Corrective Action The SW strainers were cleared of debris. 5.o* Additional Corrective Action Service water pressure to the control/reiay 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 See Ul-LER 87-005 Ul-LER 87-018 8.0 Manufacturer/Model Number N/A

• U.S.GPO: 1988-D-824*538/455 September 11, 1987 U.S. Nuclear Regulatory Cmmnission Document Control Desk 016 Phillips Building Washington, D.C. 20555 Gentlemen:

VIRGINIA ELECTRIC AND POWER COMPANY Surry Power Station P. 0. Box 316 Surry, Virginie 23883 Serial No.: Docket No.: Licensee No. : 87-023 50-280 DPR-32 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 87-021-00 This report has been reviewed by the Station Nuclear Safety and Operating Cmmnittee and will be reviewed by Safety Evaluation and Control. 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 4~1/ ~\ / \ \