ML18150A497

LER 87-014-00:on 870630,discovered That Auxiliary Feedwater (AFW) Could Be Lost to Operating Unit in Event of High Energy Line Break in Main Steam Valve House.Caused by Poor Review of AFW Supply.Review continuing.W/870730 Ltr

ML18150A497
Person / Time
Site:	Surry
Issue date:	07/30/1987
From:	Benson D VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
87-016, 87-16, LER-87-014, LER-87-14, NUDOCS 8708050149
Download: ML18150A497 (4)

Text

POW 28-06-_01 NRC Form 366 * (9-83,) U.S. NUCLEAR REGULATORY COMMISSION APPROVED 0MB NO. 3160,0104 EXPIRES: 8/31/88 LICENSEE EVENT REPORT (LER) FACILITY NAME (1) !DOCKET NUMBER (2) PAGE 131

• Surry P9wer *station.

Unit 1 o I 5 I o Io I o 12 I 8 I O 1 loF O I 3 TITLE (41 Inadequate R*eview of AFW Suoply FollowinQ a HELB in Safecrnards EVENT DATE (5) LER NUMBER (6) REPORT DATE (71 OTHER FACILITIES INVOLVED (Bl MONTH DAY YEAR YEAR FACILITY NAMES DOCKET NUMBER(SI o I 6 31 o a 1 al 1 .:.... ol 1 14 -o I o ol 1

• 3 I o a I 1 01s1010101 I I OPERATING THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check one or more of the folloV(inlJ)

(11) MODE (9) N 20.402(b) 20.406(cl 50,73(11(2)(ivl 73.71(bl -POWER 1

• 20.406(1)(1

)(I) LEVEL -<101 1 I O I O 20.405t1H1Hm

,...._ _,__ &0.36(c){1) 50.73(11(21(v) 73.71(cl ,__. -50.38(cl(2) 50.73(1)(2l{viil . OTHER (Spacify in Abstr*ct bl/ow and in T*Kt, NRC Form ,__. --=~== :::::::::;:

60.73(11(21(11

&0.73(1)(2)(vllll(A) 366A) -,...._ 50,73(11{2){ill 50.73(11(21(vllll(BI

--50.73(11(2)(iiil 50.73(1)(21(,i)

LICENSEE CONTACT FOR THIS LER (121 NAME TELEPHONE NUMBER AREA CODE D. L. Benson, Stat~n Manager . 81 01 4 31 51 7 I -I 31 11 8 Ill CAUSE SYSTEM COMPONENT I I I I I I I I COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (131 TURER I I I I I I SUP~LEMENTAL REPORT EXPECTED (141 SYSTEM I I COMPONENT.

I I I I I I . MANUFAC-TURER I I I I I I EXPECTED SUBMISSION MONTH DAY YEAR :1 YES /If v**. complete EXPECTED SUBMISSION DATE) DATE (151 nl1 ~11 RIR ABSTRACT (Limit to 1400 spaces, i.B., approximately fifteen single-space typewritten lines} (161 NRC Form 386 19-83) On June 30, 1987 with Unit One at 100% power and Unit Two at 69% power, *it was determined as a result of a company initiated

• safety system functional inspection, that a unique scenario could exist whereby auxiliary feedwater (AFW) {EIIS-BA}

could be lost to*an operating unit. In the event of a high energy line break (HELB) in the main steam valve house (MSVH) of an operating unit, the AFW pumps {EIIS-P} on that unit could be rendered inoperable due to the harsh environment.

With the unaffected unit at cold shutdown and only one of its motor driven AFW pumps available for cross connect to the affected unit, an assumed loss of offsite power, with a single failure could result in a loss of AFW to the affected unit. Administrative controls have been established to ensure that . when a unit is above 350 degrees/450 psig, two motor driven AFW pumps will be available from the other unit. Engineeririg is reviewing the original s~fety analysis for the HELB (loss of AFW) to assess the adequacy of the evaluation and determine if additional corrective actions are required.

97oso~o 00 1il i~~&eo PDR " PDR s . ...._\ t P*' p., ,

NRC Form 366A* (9-83) FACILITY NAME (11 POW 28-06~01 LICENSEE EVENT REPORT (LER) TEXT CONTINUATION*

U,S, NUCLEAR REGULATORY COMMISSION APPROVED 0MB NO. 3150--0104 EXPIRES: 8/31/88 DOCKET NUMBER (21 LER NUMBER (61 PAGE (31 ?Urry Power Station, Unit 1 o Is Io Io I o 12 1 a I o a 11 -o I 114 -o I o -o I 2 oF o 13 TEXT /ff tnOf9 _,,. i& n,quintd, usa additional NRC Farm 366A 's/ (171 . NRC FORM 366A (9-831 1. 0 Description of the Event* On June 30, 1987 with Unit One at 100% power and Unit Two at 69% power, it was determined as a result of a company initiated safety system functional inspection, that a unique scenario could exist whereby auxiliary feedwater

• (AFW) {EIIS.:..BA}

could be lost to an operating unit. In the event of a high energy line break (HELB) in the main steam valve house (MSVH) of an operating unit, the AFW pumps {EIIS-P} on that unit could be rendered inoperable due to the harsh environment.

With the unaffected unit at cold .shutdown and only one of its motor driven AFW pumps available.*

for cross connect to the affected unit, an assumed loss of offsite power, with a single failure could result in a loss of AFW to' the affected unit. The existing Technical Specification requires that only one motor driven AFW pump be available when the unit is at cold shutdown.

This specification was developed in 1980 to provide assurance that AFW could be supplied from one unit to another in the event that the AFW pumps in one unit were destroyed by fire (Appendix R). The HELB event was not considered at that time, and Appendix R does not require cqnsideration of the single failure criterion.

This event is reportable in accordance with lOCFR 50. 73(a) (2) (v). 2.0 Safety Consequences and Implications This scenario is not analyzed in the UFSAR. ever, a main steam line break is a condition IV event and is of very low probability.

Engineering is reviewing the original safety analysis to determine whether an unreviewed safety question exists. Additionally, Functional Restoration Procedure H.l provides guidance in-the event of total loss of FW and AFW to the Steam Generators.

Further protection is provided through an extensive non-destructive testing program of the main steam postulated break points in the main steam valve house .

NRC Form 366A 19-831 FACILITY NAME (1) e .pow 28-06-01 e .. LICENSEE EVENT REPORT (LERI TEXT CONTINUATION DOCKET NUMBER 121 U.S. NUCLEAR REGULATORY COMMISSION APPROVED 0MB NO. 3150-0104 EXPIRES: 8/31/88 PAGE 13) SURRY POWER STATION, UNIT 1 o 15 Io Io Io 12 I 810 81 7 -o 11 I 4 lo In n I ':l OF n h TEXT (If mo,e-,,.c.

ia ,wqund, u* tldditioMI NRC Form 366A'1/ l17l NRc FOAM 366.A 19-831 3.0 Cause Section l4B.5.1.7 of the UFSAR considers a HELB in the MSVH and assumes that should all three of the affected units AFW pumps become inoperable; redundancy is not lost because there are three AFW pumps* available from the unaffected unit. The UFSAR does not consider .the possibility that only one AFW pump from the unaffected unit might be available when that unit is at cold shutdown.

4.0 Immediate Corrective Action Administrative controls have been established to ensure that when a unit is above 350 degrees/450 psig, two motor driven AFW pumps will be available from the other unit. ,. 5.0 Additional Corrective Actions Engineering is reviewing the original safety analysis for the HELB (loss of AFW) to assess the adequacy of the evaluation and to qetermine if additional corrective actions are required.

6.0 Actions Taken to Prevent Recurrence None. 7.0 Similar Events None 8.0 Manufacturer/Model Number N/A

• U.S.GPO: 1986*0*824-538/455

.. e Vepco . July 30, 1987 U.S. Nuclear Regulatory Commission Document Control Desk 016 Phillips Building Washington, D.C. 20555 Gentlemen:

Pursuant to Surry Power Station Technical and Power Company hereby submits the for Surry Unit 1 and 2. VIRGINIA ELECTRIC AND POWER COMPANY P, D. Box 315 Surry, Virginia 23883 Serial No: 87-016 Docket No: 50-280 50-281 License No: DPR-32 DPR-37 Specifications~

Virginia Electric following Licensee Event Report REPORT NUMBER 87-014-00 This report has been reviewed by the Station Nuclear Safety and Operating Committee and will be reviewed by Safety Evaluation and Control. Very truly yours, David L. Benson Station Manager Enclosure pc: Dr. J. Nelson Grace Regional Administrator Suite 2900 101 Marietta Street, NW Atlanta, Georgia 30323