05000458/LER-1993-010
| ML20056F032 | |
| Person / Time | |
|---|---|
| Site: | River Bend  |
| Issue date: | 08/16/1993 |
| From: | Booker J, Lorfing D GULF STATES UTILITIES CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| LER-93-010, LER-93-10, RBG-38878, NUDOCS 9308250443 | |
| Download: ML20056F032 (5) | |
| Event date: | |
|---|---|
| Report date: | |
| 4582093010R00 - NRC Website | |
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8e.'g GULF STATES D T:LITIES col >fPANY j
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August 16, 1993 l RBG- 38878 {
File Nos. G9.5, G9.25.1.3 ;
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U.S. Nuclear Regulatory Commission !
Document Control Desk i Washington, D.C. 20555 !
Gentlemen:
t River Bend Station - Unit 1 ,
Docket No. 50-458 !
l Please find enclosed Supplement I to Licensee Event Report No.93-010 for !
River Bend Station -Unit 1. This supplemental report is submitted to provide the i status of additional reviews of procedural guidance as part of the corrective action ,
for this event. :5 t
Sincerely, !
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J. E Booker ,
Manager - Safety Assessment !
and Quality Verification ,
River Bend Nuclear Gmup ffDNIJJPS/DRD/DCH/kym B73>h(p ,
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23000S ,y> ;
i 9308250443 930816 79 IfI !
- D l ADOCK 05000453' PDR as hi .
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cc: U.S. Nuclear Regulatory Commission !
611 Ryan Plaza Drive, Suite 400 !
Arlington, TX 76011 l
i NRC Resident Inspector "
P.O. Box 1051 i.
St. Francisville, LA 70775 !
INPO Records Center -
700 Galleria Parkway [
Atlanta, GA 30339-5957 !'
Mr. C.R. Oberg 3
Public Utility Commission of Texas j 7800 Shoal Creek Blvd., Suite 400 North j Austin, TX 78757 !
1 Depanment of Environmental Quality Radiation Protection Division l P.O. Box 82135 i
Baton Rouge, LA 70884-2135 ATrN: Administrator #
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l NRC FORM 366 U.S. NUCLEAR RIGJLATORY CDNISSION APPROVED BY CMB NO. 3150-0104 (5-92) EXPIRES 5/31/95 E ST IMATED SURDEN PER RESPONSE TO COMPLY WITH
'" I3U" LICDTSEE EVENT REPORT (LER) $ARpl"$^MgNT5 REGARDING BURDEN ES MATE b THE INFORMATION AND RECORDS MANAGEMENT BRANCH (MNBB 7714), U.S. NUCLEAR REGULATORY COMMISSION, (See reverse for required number of digits / characters for each block) WASHINGTON, D: 20555-0001, AND TO THE PAPERWORK REDUCTION PROJECT (3150-0104), OFFICE OF MANAGEMENT AND BUDGET, WASHINGTON, DC 20503.
FACILITY NAME (1) DOCKET WIA4BER (2) PAGE (3)
RIVER BEND STATION 05000458 1 OF 4 TITLE (4) LDSS OF SHUTDOWN COOLING DURING DE-ENERGlZATION OF A POWER DISTRIBUTION PANEL EVENT DATE (5) (ER NLMBER (6) REPORT DATE (7) OTHER FACILITIES INVOLVED (8)
MONTH CAY YEAR YEAR MONTH DAY YEAR NUMBER NUMBER 05000 FACILITY hAME DOCKET NUMBER 05 14 93 93 -- 010 -- 01 08 16 93 05000 OPE RAT ING THIS REPORT IS SUBNITTED PURSUANT TO THE REQUIREQ 3 OF 10 CFR 6: (Check one or more) (11)
EDE (9) 20.402(b) 20.405(c) x 50.73(a)(2)(iv) 73. 71(b)
POWER 20.405(a)(1)(i) 50.36(c)(1) 50.73(a)(2)(v) 73.71(c)
LEVEL (10) 20.405(a)(1)(ii) 50.36(c)(2) 50. 73(a)(2)(vi i ) OTHER 20.405(a)(1)(iii) 50.73(a)(2)(i) 50.73(a)(2)(viii)(A) (Specif y in 20.405(a)(1)(iv) 50.73(a)(2)(ii) A t act ow 50.73(a)(2)(viii)(B)
. 20.405( a )(1 )( v) 50.73(a)(2)(iii) 50.73(a)(2)(x) NaC Form 366A) '
L ICE NSE E CONT ACT FOR THIS l E R (12)
NAME TELEPHONE NUMBER (include Area Code) l DAVID N. LORFING, SUPERVISOR - NUCLEAR LICENSING (504) 381-4157 (XMPLETE ONE LINE FOR EACH CCMPONENT FAf tURE DESCRIBED IN THIS REPORT (13)
CAUSE SYSTEM COMPONENT MANUFACTURER CAUEE SYSTEM COMPokENT MANUFACTURER 0
SUPPLEMENTAt REPORT EXPECTED (14) EXPECTED "*" UA yrs SUBMISSION (If yes, conplete EXPECTED SUBMISSION DATE). X No ,
DATE (15) l ABSIRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines) (16)
On 05/14/93 with the plant in Operational Condition 4 (Cold Shutdown), shutdown cooling (SDC) was lost for approximately three minutes when one of the SDC suction valves closed. This occurred due to the initiation of a spurious engineered safety feature (ESF) actuation signal during de-energization of a 120 VAC power distribution panel. Therefore, this report is submitted pursuant to 10CFR50.73(b)(2)(iv) as an ESF actuation.
The root cause of this incident was that on-shift management personnel missed the need for compensatory measures when opening breaker #22 to prevent a loss of SDC. Corrective actions include revising procedum! guidance to clarify which valve isolates when breaker #22 is opened. The duration of the loss was minimal (3 minutes) and instmmentation indicated no change in reactor coolant temperature.
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NRC FORM 366 (5-92)
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I REQUIRED NUMBER OF DIGITS / CHARACTERS FOR EACH BLOCK BLOCK maEER OF EDEER TITLE DIGITS / CHARACTERS 1 UP TO 46 FACILITY NAME 8 TOTAL DOCKET NUMBER 3 IN ADDITION TO 05000 3 VARIES PAGE NUMBER 4 UP 10 76 TITLE 6 TOTAL 5 EVENT DATE 2FRL'M 7 TOTAL 2 FOR YEAR LER NUMBER 3 FOR SEQUENTIAL NUMBER 2 FOR REVISION NUMBER 7 REPORT DATE 2 E CK UP TO 18 -- FACILITY NAME O OTHER FACILITIES INVOLVED 8 TOTAL -- DOCKET NUMBER 3 IN ADDITION TO 05000 9 1 OPERATING MODE 10 3 POWER LEVEL s
REQUIREMENTS OF 10 CFR CHECK EDX THAT APPLIES 12 UP TO 50 FOR NAME LICENSEE CONTACT 14 FOR TELEPHONE CAUSE VARIES 2 FOR SYSTEM 13 4 FOR COMPONENT EACH COMPONENT FAILURE 4 FOR MANUFACTURER NPRDS VARIES CHECK BOX THAT APPLIES SU FME R R P OU EX N D 15 EXPECTCD SUBMISSION DATE 2 K
CRC FORM 366A U.S. CDCLEAR REEULATORY COMISSitD APPROUfD B7 OMB CD. 31s0-0104
'(5-92) EXPIRES 5/31/95 ES11MA S BURDEN PER RESPONSE TO COMPLY WITH THIS INfuRMATION COLLECTION REQUEST: 50.0 HRS.
FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO LICENSEE EVENT REPORT (LER) THE INFORMATION AND RECORDS MANAGEMENT BRANCH TEXT CONTINUATION (MNss 7 m ), U.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555 0001, AND TO THE PAPERWORK REDUCTION PROJECT (3150-0104), OFFICE OF MANAGEMENT AND BUDGET, WASHINGTON, DC 20503.
FAtlllTY NAME (1) DOCKET NUMBER (?) LER NUMBER (6? PAGE (3)
YEAR SEQUEUTIAL REVISION NUMBER NUMBER RIVER BEND STATION 05000458 2W4 93 -- 010 -- 01 ,
TEXT (If more space h required, use additional copiec of NRC Fnrm 366A) (1r)
REPORTED CONDITION On 05/14/93 with the plant in Operational Condition 4 (Cold Shutdown), shutdown cooling (SDC) ovas lost for approximately three minutes when one of the SDC suction valves closed. This occurred due to the initiation of a spurious engineered safety feature (ESF) actuation signal during de-energization of a 120 VAC power distribution panel. Therefore, this report is submitted pursuant to 10CFR50.73(b)(2)(iv) as an ESF actuation.
INVESTIGATION On 05,14/93, preparations were in progress to allow electrical maintenance to repair power line conditioner SCM"XRCl4A1. This power line conditioner supplies panel SCM*PNL0l A. This work was being done under maintenance work order (MWO) R158874. Operations Section Procedure (OSP)-0019, " Electrical Load Lists" (attachment 43 and enclosure 43), was being used to de-energize all loads on SCM*XRCl4Al.
When breaker ("BKR*) #22 was opened, an isolation signal was genented that caused valve E12*MOVF008 (*20*) to close. This caused residual heat removal (RHR) pump "A" (*P*) to trip.
- Control room operators recognized immediately that shutdown cooling had been lost, and corrective actions were initiated. Breaker #22 on SCM*PNLOI A was closed, the isolation signal was reset, E12*MOVF008 was opened and RHR pump "A" was staned to re-establish shutdown cooling. The pump trip occurred at i
1310 and shutdown cooling was restored at 1313. The total time that shutdown cooling was not in service was three minutes. Instrumentation in the control room indicated no rise in reactor coolant temperature i during this time period. Abnormal Operating Procedure (AOP)-0051, " Loss of Decay Heat Removal" was -
l used to assist in restoring shutdown cooling and AOP-0003, " Automatic Isolations," was used to restore any other valves that weuld have closed when breaker #22 was opened. All other valves that would have closed from this ESF signal were already in the closed position due to plant conditions, with the exception of l E12 MOVF053A, the shutdown cooling return valve. This valve was opened after RHR pump "A" was j started to re-establish flow to the reactor.
- Operations Section Procedure (OSP)-0019 gives directions for compensatory measures to take when de-energizing electrical buses and panels. This procedure provides guidance for SCM*PNLOI A which had been independently reviewed by the Shift Supen'isor, Control Operating Foreman and Shift Technical i
Advisor. All three individuals did not recognize the fact that measures were needed to prevent a loss of shutdown cooling when opening breaker #22. Once shutdown cooling had been re-established, steps were i taken to prevent isolation of the Division I shutdown cooling valves so that shutdown cooling would not be i
lost again. The de-energization of SCM*PNLOI A was then completed with no other problems.
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NRC FORM 366A ($ 92)
ERC 70R.' 366A U.S. NUCLEAR REGULATORY Cukt41SSIC3 APPROVED itY OMB CO. 3150-0104
"(5-92) EXNRES 5/31/95
' ESTIMATED BURDEN FER RESPONSE TO COMPLY WITH THIS % FORMATION COLLECTION REQUEST: 50.0 HRS.
FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO LICENSEE EVENT REPORT (LER) THE INFORMATION AND RECORDS MANAGEMENT BRANCH TEXT CONTINUATION (MNBB 7714), U.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555-0001, AND TO THE PAPERWDRK REDUCTION PROJECT (3150-0104), OFflCE OF MANAGEMENT AND BUDGET, WASHINGTON, DC 20503.
TACILITY NAME (1) DOCtIT N!MBER (?) (IR WlMBER (6) PAGr (3)
YEAR SEQUENTIAL REVISION yuppER NUMBER RIVER BEND STATION 05000458 3@4 93 -- 010 -- 01 TEXT (if more space is required, use a%tional copics of NRC Foran 366A) (17)
ROOT CAUSE The root cause of this incident was that on-shift management personnel missed the need for compensatory measures when opening breaker #22 to prevent a loss of SDC. This occurred during the reviews of attachment 43 and enclosure 43 to OSP-0019. Contributing factors to this oversight were as follows:
- 1. The compensa'.ory measures to take for opening breaker #22 were very poorly written and led to improper interpretation of what actions needed to be taken. The recommendations for breaker #22 in enclosure 43 reference another procedure when actuation of components can occur if preventive measures are not taken. Infonnation of this kind for all other breakers on SCM*PNLOI A is listed in enclosure 43.
- 2. The Shift Supervisor was too involved in the actual perfonnance of this evolution, and therefore unable to maintain proper oversight during the implementation of OSP-0019.
A review of previous LERs revealed that LER 89-012 was similar. In LER 89-012, a loss of shutdown cooling occurred while an operator was hanging a clearance tag. The hanging of the clearance tag required the opening of breaker #20 on panel ISCM*PNLOlB. Prior to the even the Operator reviewed the power loss effect card. This card revealed that a reactor water cleanup system (RWCU) (*CE*) isolation would occur when the breaker was opened but did not make the Operator aware of the isolation of shutdown cooling.
CORRECTIVE ACTION To prevent recurrence of this incident, the following corrective measures will be taken:
- 1. A change notice will be written for OSP-0019 attachment 43 and enclosure 43 to clearly state what valve will isolate on opening of breaker #22 on SCM*PNLOI A. All needed information will be put in enclosure 43 such that there is no need to reference another procedure.
Attachment 44 and enclosure 44 to OSP-0019 were also reviewed and the same problems are present for breaker #20 on SCM*PNLOlB. Enclesure 44 will also be changed by this change notice.
NRC FORM 366A (5-92)
I m.4
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C2C 70RM 3664 U.S. NUCLEAR REGULATC27 COMMISSION APPROVED BY OMB to. 3150-0104 ,
"(5 92) EXP!RES 5/31/95
- ESTIMATED BURDEN PER RESPONSE TO COMPLY WITH THIS INFORMATION COLLECTION REQUEST: 50.0 HRS.
FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO LICENSEE EVENT REPORT (LER) THE INFORMATION AND RECORDS MANAGEMENT BRANCH TEXT CONTINUATION (MNBB m 4), U.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555-0001, AND TO ThE PAPERWORK i' REDUCTION PROJECT (3150-0104), OFFICE OF MANAGEMENT AND BUDGET. WASHINGTON, DC 20503.
FACILITY NAME (1) DOCKET NUMBER (2) LER NUMBER (6) PAGE (3)
YEAR SEQUEhiT I AL REVISION RIVER BEND STATION 05000458 4 OF 4 93 -- 010 -- 1 T[xi (i f more <-pac e i s requi re d. use additionet copies of NRC Form 3664) (17)
- 2. A memo will be sent to all Shift Supervisors to remind them of the need to maintain pmper oversight during evolutions. This memo will also emphasize the need to stop other evolutions when performing a critical task if this is needed to prevent confusion.
- 3. This event will be included in the industry events training during requalification tmining.
- 4. GSU has reviewed applicable OSP-0019 guidance to identify additional cases in which other procedures are referenced when compensatory measures are required. Additional cases have been identified as a result of this review. GSU will evaluate- these findings and revise procedures as required by February 1,1994.
SAFETY ASSESSMENT At the time shutdown cooling was lost, the plant had been shutdown since 04/17/93 at 1519 (27 days). The duration of the loss was minimal (3 minutes) and instrumentation indicated no change in reactor coolant -
temperature.
f Note: Energy industry identification system codes are indicated in the text as (*XX*).
I NRC FORM 366A (5-92)