ML18153C608

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LER 91-002-00:on 910326,main Stream Safety Valves Out of Tolerance.Caused by Minor Setpoint Drift.Affective Valve Adjusted & Valve Tested to Verify Setpoint to Be within Required tolerance.W/910423 Ltr
ML18153C608
Person / Time
Site: Surry Dominion icon.png
Issue date: 04/23/1991
From: Kansler M
VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:
NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
91-240, LER-91-002-01, LER-91-2-1, NUDOCS 9104290115
Download: ML18153C608 (6)
v • d • e


Text

ACCELERATED DISTRIBUTION DEMONSTRATION SYSTEM

~ e. e REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)

ACCESSION NBR:9104290115 DOC.DATE: 91/04/23 NOTARIZED: NO DOCKET#

FACIL:50-281 suirry Power station, Unit 2, Virginia Electric & Powe 05000281 AUTH.NAME AUTHOR AFFILIATION .

KANSLER,M.R. Virginia Power (Virginia Electric & Power Co.)

KANSLER,M.R. Virginia Power (Virginia Electric & Power Co.)

RECIP .'NAME RECIPIENT AFFILIATION

  • R I

SUBJECT:

LER 91*-002-00:on 910326,main stream safety valves out of tolerance.caused by minor setpoint drift.Affective valve D adjustiad & valve tested to verify setpoint to be within requircad tolerance. W/910423 ltr. s DISTRIBUTION CODE: IE2 2T COPIES RECEIVED: LTR / ENCL TITLE: 50.73/50.9 Licensee Event Report (LER),-Ynciden~Rpt, et-c-.~~~~

l SIZE:

I NOTES:lcy NMSS/IMSB/PM. 05000281 A D

RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL D PD2-2 L~ 1 1 PD2-2 PD *1 1 BUCKLEY,B 1 1 s INTERNAL: ACNW 2 2 ACRS 2 2 AEOD/DOA 1 1 AEOD/DSP/TPAB 1 1 AEOD/RO.~B/DSP 2 2* NRR/DET/ECMB 9H 1 1 NRR/DET/EMEB 7E 1 1 NRR/DLPQ/LHFBll 1 1 NRR/DLPQ/LPEBlO 1 1 NRR/DOEA/OEAB 1 1 NRR/DREP/PRPBll 2 2 NRR/DST/SELB 8D 1 1 NRR/DST/SICB 7E 1 1 N~- ,.t,'-12,~.QJ 1 1 NRR/DST/SRXB SE 1 1 RE .  ;...,~*"'"'7~ 1 1 RES/DSIR/EIB 1 1 RGN2 F,I:LE 01 1 1 EXTERNAL: EG&G BRYCE,J.H 3 3 L ST LOBBY WARD 1 1 NRC PDR 1 1 NSIC MAYS,G 1 1 R NSIC MURPHY,G.A 1 1 NUDOCS FULL TXT 1 1 I

NOTES: 1 1 D

s I

A D

D NOTE TO A.LL "RIDS" RECIPIENTS:

s PLEASE HELP US TO REDUCE WASTE! CONTACT THE DOCUMENT CONTROL DESK, ROOM PI-37 (EXT. 'lfj.)79) TO ELIMINATE YOUR NAME FROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEED!

FULL TEXT CONVERSION REQUIRED TOTAL NUMBER OF COPIES REQUIRED: LTTR 34 ENCL 34

Virginia Electric and Power Company Surry Power Station '

P. 0. Box 315' Surry, Virginia 23883 April 23, 1991 U.S. Nuclear Regulatory Commission Serial No.: 91-240 Document Control Desk DocketNo.: 50-281 Washington, D. C. 20555 License No.: DPR-37 Gentlemen:

Pursuant to SUJrry Power Station Technical Specifications, Virginia Electric and Power Company hereby submits the following Licensee Event Report for Unit 2.

REPORT NUMBER 91-002-00 This report has lbeen reviewed by the Station Nuclear Safety and Operating Committee and will be r~viuwed by the Corporate Management Safety Review Committee.

Very truly yours,

/JA-/U--~

. ansler Stat on Manage:r Enclosure cc: . Regional Administrator Suite2900 101 Marietta Street, NW Atlanta, Georgia 30323 9104290115 910423 PDR ADOCK 05000281 S PDR

NRC FORM 366 (6-89) e U.S. NUCLEAR REGULATORY COMMISSION e APPROVED 0MB NO. 3150-0104

' EXPIRES: 4/30/92 ESTIMATED BURDEN PER RESPONSE TO COMPLY WTH THIS INFORMATION COLLECTION REQUEST: 50.0 HRS. FORWARD LICENSEE EVENT REPORT (LER) COMMENTS REGARDING BURDEN ESTIMATE TO THE RECORDS AND REPORTS MANAGEMENT BRANCH (P-530), U.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555, AND TD THE PAPERWORK REDUCTION PROJECT (3150-0104), OFFICE OF MANAGEMENT AND. BUDGET, WASHINGTON, DC 20503.

FACILITY NAME (1) DOCKET NUMBER (2) I PAGE 13)

Surry Power Station, Unit 2 Io Is I o Io I o I 21 8 1l 1 loF O I 3 TITLE (4)

Main Steam Safety Valves Out of Tolerance Due to Minor Setpoint Drift EVENT DATE (6) LER NUMBER (6) REPORT DATE (7) OTHER FACILITIES INVOLVED (8)

MONTH DAY YEAR YEAR tt: SE~~~~~:fL ti ~~tll/:~~ MONTH DAY YEAR . FACI LJTV NAMES DOCKET NUMBER(S)

OPERATING THIS FIEPORT IS SUBMITTED PURSUANT TO THE R~QUIREMENTS OF 10 CFR §: (Check ons or more of th* following) (11)

MODE (9) N

~---'---~

POWER L~~~L I

01 7 (5 -

~:0.402(b)

10.406(1)(1 )(I) 20,406(c) 60,38(c)(1) 50.73(1)(2)(iv) 60.73(1)(2)(v) 73.71(bl 73.71(cl

_  :!0.405(1)(1)(ii)

-..i 50.38(c)(2)

- 60.73(11(2) (vii)

- OTHER /Spacify in Abst~*ct btJlow and In Texr, NRC Form lftlll\1= -

!0.405(11(1 )(iii) 50,73(1)(2)(1) 60.73(1)(2)(vllll(A) 366A)
!0.406(1)(1)11*1
!0.405(11(1 )(vi - 60.73(1)(2)(ii) 50.73(1)(2)(ili) t:ICENSEE CONTACT FOR THIS LER (121 60,73(1)(2)(vlii) (Bl .

60.73(1)(2)(x)

NAME TELEPHONE NUMBER AREA CODE M. R. Kansler, Station Manager 8 I 01 4 3 I 51 7 1- I 3 1l I 81 4 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13)

MANUFAC- MANUFAC-CAUSE SYSTEM COMPONENT TURER TURER X y I I I I I I I I I I I I I I I I I I I I I SUPPLEMENTAL REPORT EXPECTED (14) MONTH DAY YEAR EXPECTED I YES (If y*s. compl*t* EXPEC1'ED SUBMISSION DATE) hi NO ABSTRACT (Limit to 1400 spaces, i.s., epproxim*ttJ/V fifttJtJn single-space typewritten lines} (16)

SUBMISSION DATE (161 I I I On March 26, 1991, with Unit 2 at 75% power during end of fuel cycle coast down, setpoint testing of the fifteen Main Steam Code Safety Valves revealed that the lift setting of 2-M:S-SV-205B was outside of the + 3% "as found" range allowed by Surry's Technical Specifications. The valve exhibited a lift se:tting of 3.3% below its nominal value (1135 psig). The safety valve was readjusted to be within the required setpoint tolerance. This event is reportable pursuant to 10CFR50.73(a)(2)(i)(B) for conditions prohibited by Technical Specifications 3.6.A, 3.6.B.3 and 3.6.D.

NRC Form 366 (IHl9)

J NRC FORM 366A (6-89)

U.S. NUCLEAR REGULATORY COMMISSION APPROVED 0MB NO. 3150-0104 EXPIRES: 4/30/92 ESTI* ED BURDEN PER RESPONSE TO COMPLY WTH oTHIS LICIENSEE E~E-REPORT (LER) INFORMATION COLLECTION REQUEST: 50.0 HRS. FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO THE RECORDS TEXT CONTINUATION AND REPORTS MANAGEMENT BRANCH (P-530). U.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555, AND TO THE PAPERWORK REDUCTION PROJECT (3150-0104), OFFICE OF MANAGEMENT AND BUDGET, WASHINGTON, DC 20503.

FACILITY NAME (11 DOCKET NUMBER (21 LER NUMBER (6) PAGE (3)

Surry Power Station, Unit 2 o 1s Io Io Io I 21s I 1 91 1 - 01 012 - o 10 o 12 OF 013 TEXT (ff,,,,,,. apaett ii tw1uitff, use additio11al NRC Fann .BA'*) (171

1. O DESCRIPTION QF. THE EVENT On March 26, *1991, with Unit 2 at 75% power during end of fuel cycle coa:;t down, setpoint testing of the fifteen Main Steam Code Safety Valves

[EIIS-SB,RV] revealed that the lift setting of 2-MS-SV-205B was outside of the +/-. 3% "as found" range allowed by Surry's Technical Specifications.

The valve exhibited a lift setting of 1097 psig, 3.3% below its nominal value (1135 psig). This event is reportable pursuant to 10CFR50. 73(a)(2)(i)(B) for conditions prohibited by Technical Specifications 3.6.A, 3.6.B.3 and 3.6.D.

2. 0 fil!J~NIFICANT SAFETY CONSEQUENCES AND IMPLICATIONS The: Main Steam Code Safety Valves are provided to prevent overpressure conditions in the secondary side of the steam generators and to ensure residual heat removal capability by relief of steam to atmosphere if the main condenser and steam generator power operated reli,ef valves are unavailable. Since the "as found" setting was below the nominal lift setpoint, the valve would open earlier than anticipated by the accident analysis but above the setpoint of the steam generator power operated relief valve (1035 psig).
  • Therefore, the low safety valve lift setpoints did not increase the probability of excessive blowdown and had no impact on the accident analysis. Because the safeties would have performed their safety function, the health and safety of the public were not affected .

3.0 .c.AUSE OF THE EVENT The, Main Steam Safety Valve experienced a minor setpoint drift which can be expected under normal operating conditions. Although the spe,::ific cause of this setpoint drift is not known, its occurrence is well documented in the industry and is not considered to be abnormal.

4.0 lMJ\:fEDIATE CORRECTIVE ACTION<S}

The. affected valve was adjusted to within + 1% of the required setpoints.

s. O All.UITIONAL CORRECTIVE ACTION<S}

The valve was tested three. times to verify lift setpoint to be within its required tolerance and based upon evaluations of the test data, it was determined that no additional testing or maintenance was required.

6. O ACTIONS TO PREVENT RECURRENCE NoJrJ.e.

NRC Form 366A (6-891

e NRC FORM 366A

  • U.S. NUCLEAR REGULATORY COMMISSION (6-89) - APPROVED 0MB NO. 3150-0104

- EXPIRES: 4/30/92 ESTIMATED BURDEN PER RESPONSE TO COMPLY WTH THIS LIC:ENSEE EVENT REPORT (LER) INFORMATION COLLECTION REQUEST: 50.0 HRS. FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO THE RECORDS TEXT CONTINUATION AND REPORTS MANAGEMENT BRANCH (P-530). U.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555, AND TO 1HE PAPERWORK REDUCTION PROJECT (3150-0104), OFFICE OF MANAGEMENT AND,BUDGET, WASHINGTON. DC 20503.

FACILITY NAME (1) DOCKET NUMBER (2) LEA NUMBER (6) PAGE (3)

Surry Power Station, Unit 2 o Is Io I o I o I 2 1s I 1 9 I 1 - o I o12 - o ,o o I 3 oF o13 TEXT (If man, apace i.s n,quir.d, uso *ddltk.nal NRC Fann 3ti&A'a) (17)

7. O SIMILAR EVENTS Unit 1 LER 86-016-00, "B" Main Steam Safety Valve Setpoints.

Unit 1 LER 90-011-00, Main Steam Safety Valves Out of Tolerance Due to Minor Setpoint Drift.

8. O .A..1!DITIONAL INFORMATION Dresser 6" inlet, 10" outlet safety relief valve, Type 3707RA-RT21 (2-MS-SV-205B).

NRC Form 366A (~9)

" e LER 281-91-002-00 VERIFICATION OF ACCURACY Correspondence Review Form Signatures.

DR - S 0364 Work Orde:r #3899195894 Procedure 2-MPT-0427-01 ACTION PLAN None.

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