ML20156A122
| ML20156A122 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom  |
| Issue date: | 06/04/2020 |
| From: | Christopher Hunter NRC/RES/DRA/PRB |
| To: | |
| Littlejohn J (301) 415-0428 | |
| References | |
| LER 1985-003-00 | |
| Download: ML20156A122 (5) | |
Text
LER No.:
Event
Description:
Date of Event:
Plant:
PRECURSOR DESCRIPTION SHEET 27 7/85-003 Loss of One RHR and LPCI Train June 3, 1985 Peach Bottom 2 EVENT DESCRIPTION Sequence On June 1 during a test, the "A" residual heat removal (RUR) system outboard injection valve (154A) failed in mid-position.
This failure was not detected.
On June 3, the ERR loop A injection valve failed to open in a test and could not be opened manually at the valve.
This failure also affected LPCI system train A operation.
The valve's lock nut and yoke nut had been damaged in a May 29 hydro test.
A trust bearing was also found damaged.
Corrective Action The valve was repaired.
Plant/Event Data Systems involved:
LPCI and RHR Components and Failure Modes Involved:
Injection valve -
failed in test twice Component Unavailability Duration:
96 h Plant Operating Mode:
6 (0% power)
Discovery Method:
Testing Reactor Age:
11.8 years Plant Type:
BWR Comments None Event Identifier:
277/85-003 E-101
MODELING CONSIDERATIONS AND DECISIONS Initiators Modeled and Initiator Nonrecovery Estimate Transient, LOOP, small LOCA (Postulated event)
Base case Events are conservatively assumed to occur at power Branches Impacted and Branch Nonrecovery Estimate LPCI base case one train failed RHR (shutdown base case One train failed coding mode)
Plant Models Utilized BWR plant Class C Event Identifier:
277/85-003 E-102
CONDITIONAL CORE DAMAGE CALCULATIONS LER Number:
Event Description-Event Date:
Plant:
277/85-003 Loss of One RHR and One LPCI Train 6/3/B5 Peach Bottom 2 UNAVAILABILITY, DURATION= 9b NON-RECOVERABLE INITIATING EVENT PROBABILITIES TRANS LOOP LOCA SEQUENCE CONDITIONAL PROBABILITY SUMS End State/Initiator
- 1.
- 8.
480E-14 1.777E-13
- 1.
037E-12 CD TRANS LOOP LOCA Total 3.984 E-06
- 9. 604E-09
- 2. 393E-08
- 0.
OOOE+00
- 0.
OOOE+OO
- 0.
OOOE+00
- 0.
OO0E+00 DOMINANT SEQUENCE.S End State: CV Conditional Probability:
9.905E-11 156 TRANS SCRAM -SLC.OR.RODS PCS/TRANS SRV.CLOSE FW/PCS.LOCA HPCI RCIC/LOCA -SRV.ADS -COND/FW.PCS RHR Event Identifier: 277/85-003 E-103
(SDC) -RHRiSPCOOL)/-LPCI.RHR(SDC)
End State; CD Conditional Probability:
3.237E-06 101 TRANS -SCRAM PCS/TRANS SRV.CHALL/TRANS.-SCRAM -SRV.CLOSE -FW/PCS.TRANS RHR(SDC) RHR(SPCDOL)/-LPCI.RH R(SDC)
C.1.AND.V/RHR(SDC).RHR(SPCOOL)
SEQUENCE CONDITIONAL PROBABILITIES Sequence End State Seq. Prob Non-RecoVtt 101 TRANS -SCRAM PCS/TRANS SRV.CHALL/TRANS.-SCRAM -SRV.CLUSE -FW
/PCS.TRANS RHR(SDC) RHR(SPCOOL)/-LPCI.RHR(SDC) C.1.AND.
V/RHR(SDC).RHRiSPCOOL) 102 TRANS -SCRAM PCS/TRANS SRV.CHALL/TRANS.-SCRAM -SRV.CLOSE FN
/PCS.TRANS -HPCI RHR(SDC) RHR(SPCOOL)/-LPCI.RHR(SDC) C.
I.AND.V/RHR(SDC).RHR(SPCDOL) 135 TRANS SCRAM -SLC.OR.RODS PCS/TRANS -SRV.CLDSE FW/PCS.TRANS HPCI RCIC/TRANS.OR.LOOP -SRV.ADS -CONDIFW.PCS RHR(SDC) -
RHR(SPCDDL) I-LPCI.RHR(SDC) 139 TRANS SCRAM -SLC.OR.RODS PCS/TRANS -SRV.CLOSE FWIPCS.TRANS HPCI RCIC/TRANS.OR.LOOP -SRV.ADS CDND/FW.PCS -LPCS RHR(
SDC) -RHRISPCOOL)/-LPCJ.RHR(SDC) 156 TRANS SCRAM -SLC.OR.RDDS PCS/TRANS SRV.CLOSE FW/PCS.LOCA HPCI RCIC/LOCA -SRV.ADS -CDND/FW.PCS RHR(SDC) -RHR(SPCOO L)/-LPCI.RHR(SDC) 160 TRANS SCRAM -SLC.OR.RODS PCS/TRANS SRV.CLDSE FN/PCS.LDCA HPCI RCIC/LDCA -SRV.ADS COND/FW.PCS -LPCS RHRfSDC) -RHR (SPCOOL) /-LPCI.RHR(SDC) 227 LOOP -EMER6.PIJWER SCRAM -SLC.DR.RODS HPCI RCIC/TRANS.OR.LDD P -SRV.ADS -LPCS_ RHR(SDC) -RHR(SPCDOL)/-LPCI.RHR(SDC) 315 LOCA SCRAM -SLC.OR.RODS PCS/LOCA FW/PCS.LDCA HPCI -SRV.ADS
-COND/FW.PCS RHR(SDC) -RHR(SPCODL)/-LPCI.RHR(SDC) 319 LOCA SCRAM -SLC.DR.RODS PCS/LOCA FW/PCS.LDCA HPCI -SRV.ADS COND/FW.PCS -LPCS RHR(SDC) -RHR(SPCDOL)/-LPCI.RHR(SDC)
CD CD CV CV CV CV CV CV CV 3.237E-06 t 1.015E-01 5.66b0E-07
- 3.
82SE-02 4.619E-11 2.285E-02 2.377E-11 1.177E-02 9.905E-11 I 4.008E-02 5.097E-11 2.065E-07 iJI1BE-11 3.461E-02 1.640E-11 1.363E-02
- 8.
43BE-12 7.020E-03 I dominant sequence for end state It non-recovery credit for edited case Note:
Conditional probability values are differential values which reflect the added risk due to observed failures.
Parenthetical values indicate a reduction in risk compared to a similar period without the existing failures.
MODEL:
DATA:
b:bvrctree. cup b:peachpro.cmp No Recovery Limit BRANCH FREgUENCIES/PRDBABILITIES Event Identifier:
277/B5-003 E-104
Branch System BrachSysemNon-Recov Opr Fail TRANS LOOP LOCA SCRAM SLC. OR. RODS PCS/IRANS PCS/LOCA SRV. CHALLITRANS. -SCRAM SRV. CHALL/TRANS. SCRAM SRV. CHALL/LOOP. -SCRAM SRV. CHALL/LOOP. SCRAM SR?. CLOSE EMERG. POWER FW/PCS. TRANS FW/PCS.LOCA HPCI RCIC/TRANS. OR. LOOP RCIC/LOCA CRD SRV. ADS COND/FW. PCS LPCS LPCI (RHR) /LPCS Branch Model:
I.OF.2 Train I Cond Prob:
Train 2 Cond Prob:
RHRSWILPCS. LPCI.TRANS RHRSW/LPCS. LPCI.LOOP RHRSW/LPCS.LPCI.LOCA RHR (SDC)
Branch Model:
I.OF.2+ser Train 1 Cond Prob:
Train 2 Cond Prob:
Serial Component Probability:
RHR(SDC) /-LPCI RHR(SDC) /LPCI RHR (SPCODL) I-LPCI.RHR (SDC)
C.
I.AND.V/RHR(SDC).RHR(SPCOOL) 111 forced-JD HARRIS 10-07-1986 14:54:34 Event Identifier: 277/B5-003
- 1.
- 1.
- 3.
- 4.
1 OOE-04
- 1.
OOOE-02
- 1.
- 1.
OOOE+00
- 1.
OOOE+00 1.000E+00 I.
O0OE+00
- 1.
OOOE+00
- 3.
- 2.
708E-04 4.600OE-01
- 1.
OOOE+00 1.000OE-01
- 6.
- 1.
OOOE+00 1.000E-02
- 6.
- 1.
000E+00
- 3.
000E-03 4.OOOE-04 > 1.000E-01 4.OOOE-03 > Failed I.
OOOE-01
- 5.
OOOE-01
- 5.
OOOE-01
- 5.
OOOE-01 2.039E-02 ) I.180E-01 4.OOOE-03 > Failed 1.00OOE-01
- 2.
OOOE-02
- 2.
OOOE-02 1.000E+00
- 2.
OOOE-02 5.200E-01 1.0OO0E+00 l.0O0E+00
- 3.
- 3.
- 1.
000E+00
- 1.
OOOE+00
- 1.
OOOE+00 1.000E+00
- 1.
O00E+00 I.
000E+00
- 1.
OOOE+00
- 1.
000E+00
- 1.
000E+00
- 5.
1IOOE-0 I 3.400E-01
- 3.
- 5.
- 5.
- 1.
OOOE+00 1.000E+00 I.
000E+00 3.400E-01
- 3.
- 3.
- 4.
OOOE-02
- 4.
OOOE-02
- 4.
OOOE-02 1.000E+00 1.000E+00
- 1.
OO0E+00
- 3.
- 4.
OOOE -02
- 4.
OOOE-02
- 4.
OOOE-02 3.400E-01 1.000OE+00J 1.000OE+00
- 1.
OOOE+00
- 3.
400E-01 E-105