ML063170289
| ML063170289 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 05/31/2006 |
| From: | NRC/RES/DRASP/DDOERA/OEGI |
| To: | |
| Shared Package | |
| ML063170246 | List: |
| References | |
| LER-05-002-00 | |
| Download: ML063170289 (29) | |
Text
1 For the initiating event assessment, the parameter of interest is the measure of the conditional core damage probability (CCDP). This is the value obtained when calculating the probability of core damage for an initiating event with subsequent failure of one or more components following the initiating event.
1 Final Precursor Analysis Accident Sequence Precursor Program ---Office of Nuclear Regulatory Research Millstone 3 Inadvertent Reactor Trip and Safety Injection Event Date: 4/17/2005 LER 423-2005-002 CCDP1 = 7.6E-06 May 31, 2006 Event Summary Description.
On April 17, 2005 at 0829, during normal 100% power operating conditions the solid state protection system (SSPS) generated an "A" Train SSPS Steam Line Pressure Low SI/MSI signal that tripped the reactor, closed the main steam isolation valves (MSIVs), and started the "A" train of the emergency core cooling system (ECCS). Following the trip, all control rods inserted and the auxiliary feedwater system actuated automatically as expected, however the turbine driven auxiliary feedwater pump (TDP) tripped on startup. Immediately following the trip, control room operators entered the emergency operating procedure network, manually initiated "B" safety injection (SI) actuation so as to have a two-train SI actuation, and continued to place the plant in a stable condition. Later into the event at 0844, operators also manually initiated "B" main steam isolation (MSI) actuation.
At 0840, reactor coolant system (RCS) pressure reached 2350 psia and both pressurizer power operated relief valves (PORVs) began cycling as designed. The pressurizer safety valves remained closed throughout the event. Safety injection was terminated at 0913. After performing their safety function, both PORVs leaked, however the leakage did not exceed the 10 gpm Technical Specification limit. Leakage was conservatively estimated to be 5.3 gpm with the plant at 2250 psia. Additionally, a field observation at 0858 reported RCS leakage from two charging system valves (3CHS*V661 and 3CHS*MV8511 B) into the auxiliary building.
Valve 3CHS*MV8511 B leakage was terminated when the valve was closed at 0905 and valve 3CHS*V661 was isolated at 1032. The leakage was determined to have commenced at 0830 and initial leakage was estimated to be approximately 60 gpm.
Regarding secondary side plant response, following the reactor trip, approximately 8 seconds after the TDP began feeding the steam generators (SGs), the TDP trip throttle valve closed.
This resulted in isolating steam to the pump turbine which then began to coast down.
Subsequent manual restart of the TDP pump occurred at 1019. The two motor driven AFW pumps provided flow to the SGs throughout the event.
LER 423-2005-002 2
Within one hour of event initiation, plant parameters were stabilized and ECCS systems were stopped and placed in a standby condition. The event was terminated at 1905.
Analysis Results The event importance is calculated to be 7.6E-06. Based on sensitivity analyses, upper and lower bounds of the event importance may be 1.6 E-05 and 2E-06. The upper bound uses TDP not recovered with a pessimistic SI termination HEP (0.01); the lower bound assumes TDP recovery and a very low SI termination HEP (0.0001).
Model Assessment summary This event was modeled as an initiating event analysis, with a weighted average combination of TRANS and SLOCA (pressurizer PORV or SRV), depending on the success of the operators to terminate the SI or not.
Key Modeling Assumptions The following key assumptions are made:
1.
AFW TDP is unavailable during the event. A sensitivity analysis with a recovered pump is also made.
2.
If the operators terminate the SI injection, the event is modeled as a transient.
3.
If the operators fail to terminate the SI injection, the event is modeled as a small LOCA (pressurizer PORV or SRV).
SPAR model used in the analysis Millstone 3 SPAR model 3.21.
Unique system and operational considerations None Modifications to event tree and fault tree models None of the SPAR model fault trees and event trees are changed.
An event tree logic is generated and used to define the weighted average combination
LER 423-2005-002 3
of TRANS and SLOCA, based on the operator action to terminate the SI. This event tree is given in Figure 1.
Initiating event probability changes None.
Basic event probability changes HPR-XHE-XM-RECIRC: Operator fails to start high pressure recirculation.
The HEP value for this basic event is 5E-03 in the SPAR model. As pointed out by the reviewer of this document, this HEP value is very conservative for this type of small LOCA where a long time period passes before RWST is depleted.
Moreover, the switchover to sump recirculation is a semi-automatic action. The plant-specific value calculated by the licensee for this operator action is 1.1E-04 and it is deemed to be a more accurate estimate of the HEP. Thus, it is used for the base case calculations.
The following two event tree nodes are introduced in Figure 1:
OP-TERM: Operators terminate SI. The time window for this is taken as hours, rather than minutes, which provides ample time to diagnose.
Failure of OP-TERM is driven by diagnosis; extra time and high stress are postulated and the HEP is estimated as 2E-03. Sensitivity analyses with higher and lower HEPs are also made.
CCDP: conditional core damage probability, given TRANS or SLOCA without TDP occurs. SPAR models are quantified to calculate these CCDPs; CCDPs with TDP available (recovered) are also calculated. The results are summarized as follows:
CCDP with TDP CCDP without TDP TRANS 1.9E-06 5.4E-06 SLOCA 1.1E-03 1.1E-03 Calculations Table 1 summarizes the results of the eight CCDP calculations made using GEM. These CCDPs are later used in Figures 1 through 4 to estimate event importance for the base case
LER 423-2005-002 4
and various sensitivities. Figure 1 shows the calculations for the base case. Additional sensitivity analyses are made, as shown in Figures 2, 3 and 4. Based on these calculations, the event importance is estimated as 7.6E-06, with upper and lower bound estimates of 1.6 E-05 and 2 E-06.
The upper bound estimate is taken from Figure 2 with TDP not recovered, coupled with a pessimistic SI termination HEP (0.01).
The lower bound is taken from Figure 2 given TDP recovery and a very low SI termination HEP (0.0001).
Conclusion The event importance is calculated to be 7.6E-06. Since this value is greater than that of the acceptance threshold for ASP program, this event should be retained in the ASP data base.
References 1.
Licensee Event Report LER 423-2005-002, issued 6/16/2005 2.
NRC Memorandum dated April 20, 2005: Special Team Inspection Charter - Millstone Unit 3 NGS.
LER 423-2005-002 5
Table 1.
Input Transient and Small LOCA CCDPs are calculated for 4 cases, using Millstone 3 SPAR_3.21 Model. Gem files for base case (Case 1) are attached.
Case 1 AFW TDP fails; HEP for HPR is set to 1.1E-04.
GEM Run CCDP TRANS-TDP-LIC 5.40E-06 SLOCA-TDP-LIC 1.10E-03 Case 2 AFW TDP is recovered; HEP for HPR is set to 1.1E-04.
GEM Run CCDP TRANS-TDP-LIC 1.90E-06 SLOCA-TDP-LIC 1.10E-03 Case 3 AFW TDP fails; HEP for HPR is set to 5 E-03.
GEM Run CCDP TRANS-TDP-LIC 5.60E-06 SLOCA-TDP-LIC 6.00E-03 Case 4 AFW TDP is recovered; HEP for HPR is set to 5 E-03.
GEM Run CCDP TRANS-TDP-LIC 1.90E-06 SLOCA-TDP-LIC 6.00E-03 HEPs for Operator terminates SI (OP-TERM) are taken as:
high 1.00E-02 base 2.00E-03 low 1.00E-04 The CCDPs and OP-TERM are used in the next set of event tree models to estimate the event CCDP for four cases.
LER 423-2005-002 6
Figure 1 Base Case Calculation (case 1)
Reactor trip with SI occurs Operators Terminate SI CCDP due to TRANSIENT or SLOCA low OP-TERM Base OP-TERM High OP-TERM OP-TERM CCDP 1
OK TRANS 2
CD 5.4E-06 5.39E-06 5.35E-06 5.4E-06 1
3 OK SLOCA 4
CD 1.1E-07 2.20E-06 1.10E-05 1.1E-03 Sum =
5.5E-06 7.6E-06 1.6E-05 Case 1 AFW TDP fails; HEP for HPR is set to 1.1E-04.
GEM Run CCDP TRANS-TDP-LIC 5.40E-06 SLOCA-TDP-LIC 1.10E-03 HEPs for Operator terminates SI (OP-TERM) are taken as:
OP-TERM 1 - OP-TERM high 1.00E-02 9.90E-01 base 2.00E-03 9.98E-01 low 1.00E-04 1.00E+00
LER 423-2005-002 7
Figure 2 Case 2 Calculation Reactor trip with SI occurs Operators Terminate SI CCDP due to TRANSIENT or SLOCA low OP-TERM Base OP-TERM High OP-TERM OP-TERM CCDP 1
OK TRANS 2
CD 1.9E-06 1.90E-06 1.88E-06 1.9E-06 1
3 OK SLOCA 4
CD 1.1E-07 2.20E-06 1.10E-05 1.1E-03 Sum =
2.0E-06 4.1E-06 1.3E-05 Case 2 AFW TDP is recovered; HEP for HPR is set to 1.1E-04.
GEM Run CCDP TRANS-TDP-LIC 1.90E-06 SLOCA-TDP-LIC 1.10E-03 HEPs for Operator terminates SI (OP-TERM) are taken as:
OP-TERM 1 - OP-TERM high 1.00E-02 9.90E-01 base 2.00E-03 9.98E-01 low 1.00E-04 1.00E+00
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Figure 3 Case 3 Calculation Reactor trip with SI occurs Operators Terminate SI CCDP due to TRANSIENT or SLOCA low OP-TERM Base OP-TERM High OP-TERM OP-TERM CCDP 1
OK TRANS 2
CD 5.6E-06 5.59E-06 5.54E-06 5.6E-06 1
3 OK SLOCA 4
CD 6.0E-07 1.20E-05 6.00E-05 6.0E-03 Sum =
6.2E-06 1.8E-05 6.6E-05 Case 3 AFW TDP fails; HEP for HPR is set to 5 E-03.
GEM Run CCDP TRANS-TDP-LIC 5.60E-06 SLOCA-TDP-LIC 6.00E-03 HEPs for Operator terminates SI (OP-TERM) are taken as:
OP-TERM 1 - OP-TERM high 1.00E-02 9.90E-01 base 2.00E-03 9.98E-01 low 1.00E-04 1.00E+00
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Figure 4 Case 4 Calculation Reactor trip with SI occurs Operators Terminate SI CCDP due to TRANSIENT or SLOCA low OP-TERM Base OP-TERM High OP-TERM OP-TERM CCDP 1
OK TRANS 2
CD 1.9E-06 1.90E-06 1.88E-06 1.9E-06 1
3 OK SLOCA 4
CD 6.0E-07 1.20E-05 6.00E-05 6.0E-03 Sum =
2.5E-06 1.4E-05 6.2E-05 Case 4 AFW TDP is recovered; HEP for HPR is set to 5 E-03.
GEM Run CCDP TRANS-TDP-LIC 1.90E-06 SLOCA-TDP-LIC 6.00E-03 HEPs for Operator terminates SI (OP-TERM) are taken as:
OP-TERM 1 - OP-TERM high 1.00E-02 9.90E-01 base 2.00E-03 9.98E-01 low 1.00E-04 1.00E+00
LER 423-2005-002 10 Attachment A: GEM Outputs GEM output files for the base case (case 1):
1.
TRANS without TDP 2.
SLOCA without TDP
LER 423-2005-002 11 I N I T I A T I N G E V E N T A S S E S S M E N T Code Ver : 7:26 Fam : MIL3_3 Model Ver : 2005/10/28 User : INEEL Init Event: IE-TRANS Ev ID: TRANS-TDP-LIC Total CCDP: 5.4E-006 Desc : Transient CCDP with licensee HEP for HPR - no TDP BASIC EVENT CHANGES Event Name Description Base Prob Curr Prob Type AFW-TDP-TM-P2 FEED PUMP P2 IS IN TEST OR M 5.0E-003 1.0E+000 TRUE HPR-XHE-XM-RECIRC OPERATOR FAILS TO START HIGH 5.0E-003 1.1E-004 IE-LLOCA LARGE LOSS OF COOLANT ACCIDE 5.0E-006 +0.0E+000 IE-LOCCW LOSS OF COMPONENT COOLING WA 4.0E-004 +0.0E+000 IE-LOCHS LOSS ODF CONDENSER HEAT SINK 9.0E-002 +0.0E+000 IE-LODCA LOSS OF DC BUS 301-A INITIAT 1.3E-003 +0.0E+000 IE-LODCB LOSS OF DC BUS 301-B INITIAT 1.3E-003 +0.0E+000 IE-LOMFW LOSS OF MAIN FEEDWATER INITI 1.0E-001 +0.0E+000 IE-LOOP LOSS OF OFFSITE POWER 3.6E-002 +0.0E+000 IE-LOSWS LOSS OF SERVICE WATER 4.0E-004 +0.0E+000 IE-MLOCA MEDIUM LOSS OF COOLANT ACCI 4.0E-005 +0.0E+000 IE-RHR-CLDIS-V RHR COLD LEG DISCHARGE ISLO +0.0E+000 +0.0E+000 IE-RHR-HLDIS-V RHR HOT LEG DISCHARGE ISLOCA +0.0E+000 +0.0E+000 IE-RHR-SUC-V RHR SUCTION LINE ISLOCA EVEN +0.0E+000 +0.0E+000 IE-SGTR STEAM GENERATOR TUBE RUPTURE 4.0E-003 +0.0E+000 IE-SI-CLDIS-V SI COLD LEG DISCHARGE ISLOC +0.0E+000 +0.0E+000 IE-SI-HLDIS-V SI HOT LEG DISCHARGE ISLOCA +0.0E+000 +0.0E+000 IE-SLOCA SMALL LOSS OF COOLANT ACCIDE 4.0E-004 +0.0E+000 IE-TRANS TRANSIENT 7.0E-001 1.0E+000 SEQUENCE PROBABILITIES Truncation : Cummulative : 100.0% Individual : 1.0%
Event Tree Name Sequence Name CCDP %Cont TRANS 18 3.7E-006 TRANS 02-02-12 7.9E-007 TRANS 02-02-10 5.5E-007 TRANS 19-08 1.0E-007 TRANS 19-18 9.2E-008 SEQUENCE LOGIC Event Tree Sequence Name Logic TRANS 18 /RPS AFW FAB 2006/05/31 10:45:09 page 1
LER 423-2005-002 12 TRANS 02-02-12 /RPS /AFW
/PORV LOSC
/RCPT /RSD
/BP1 BP2 HPI SSC1 TRANS 02-02-10 /RPS /AFW
/PORV LOSC
/RCPT /RSD
/BP1 BP2 HPI /SSC1
/PZR1 LPI TRANS 19-08 RPS /RCSPRESS
/MFW BORATION TRANS 19-18 RPS RCSPRESS Fault Tree Name Description AFW AUXILIARY FEEDWATER BORATION MILLSTONE 3 EMERGENCY BORATION FOR ATWS BP1 RCP SEAL STAGE 1 INTEGRITY BP2 RCP SEAL STAGE 2 INTEGRITY FAB FEED AND BLEED HPI HIGH PRESSURE INJECTION LOSC LOSS OF ALL SEAL COOLING LPI LOW PRESSURE INJECTION MFW MILLSTONE 3 MAIN FEEDWATER FAULT TREE PORV PORVs ARE CLOSED PZR1 RCS DEPRESS FOR LPI/RHR RCPT REACTOR COOLANT PUMP TRIP RCSPRESS FAILURE TO LIMIT RCS PRESSURE TO <3200 PSI RPS REACTOR TRIP RSD RAPID SECONDARY DEPRESS SSC1 RCS COOLDOWN (POST-LOCA)
SEQUENCE CUT SETS Truncation: Cummulative: 100.0% Individual: 1.0%
Event Tree: TRANS CCDP: 3.7E-006 Sequence: 18 CCDP % Cut Set Cut Set Events 2.0E-006 53.53 HPI-XHE-XM-FB AFW-MDP-CF-START 1.5E-007 4.05 HPI-XHE-XM-FB AFW-MDP-FS-1A AFW-MDP-TM-1B 2006/05/31 10:45:09 page 2
LER 423-2005-002 13 1.5E-007 4.05 HPI-XHE-XM-FB AFW-MDP-TM-1A AFW-MDP-FS-1B 1.2E-007 3.17 HPI-XHE-XM-FB AFW-MDP-CF-RUN 9.0E-008 2.43 HPI-XHE-XM-FB AFW-AOV-CC-F083 AFW-MDP-TM-1A 9.0E-008 2.43 HPI-XHE-XM-FB AFW-AOV-CC-F085 AFW-MDP-TM-1B 6.9E-008 1.87 PPR-SRV-CC-PRV2 AFW-MDP-CF-START 6.9E-008 1.87 AFW-MDP-CF-START PPR-SRV-CC-PRV1 5.2E-008 1.39 HPI-XHE-XM-FB AFW-MDP-TM-1A AFW-MDP-FR-1B 5.2E-008 1.39 HPI-XHE-XM-FB AFW-MDP-FR-1A AFW-MDP-TM-1B 4.8E-008 1.30 HPI-XHE-XM-FB AFW-TNK-FC-DWST 4.8E-008 1.30 HPI-XHE-XM-FB AFW-TNK-FC-CST 4.5E-008 1.21 HPI-XHE-XM-FB AFW-MDP-FS-1A AFW-MDP-FS-1B 4.0E-008 1.08 HPI-XHE-XM-FB AFW-PMP-FR-P1B AFW-MDP-TM-1A 4.0E-008 1.08 AFW-PMP-FR-P1A HPI-XHE-XM-FB AFW-MDP-TM-1B Event Tree: TRANS CCDP: 7.9E-007 Sequence: 02-02-12 CCDP % Cut Set Cut Set Events 3.1E-007 38.89 CVC-XHE-XM-ACOOL NOTSUMMER SWS-FAN-CF-HVY2ABS /RCS-MDP-LK-BP1 RCS-MDP-LK-BP2 CVC-P3AOP-P3BSTBY 3.1E-007 38.89 CVC-XHE-XM-ACOOL NOTSUMMER SWS-FAN-CF-HVY2ABS /RCS-MDP-LK-BP1 RCS-MDP-LK-BP2 CVC-P3BOP-P3ASTBY 2.5E-008 3.11 CVC-XHE-XM-ACOOL NOTSUMMER SWS-PND-CF-23AB /RCS-MDP-LK-BP1 RCS-MDP-LK-BP2 CVC-P3BOP-P3ASTBY 2.5E-008 3.11 CVC-XHE-XM-ACOOL NOTSUMMER SWS-PND-CF-23AB /RCS-MDP-LK-BP1 RCS-MDP-LK-BP2 CVC-P3AOP-P3BSTBY 2.4E-008 3.09 CVC-XHE-XM-ACOOL NOTSUMMER SWS-FAN-CF-HVY2ABR /RCS-MDP-LK-BP1 RCS-MDP-LK-BP2 CVC-P3BOP-P3ASTBY 2.4E-008 3.09 CVC-XHE-XM-ACOOL NOTSUMMER SWS-FAN-CF-HVY2ABR /RCS-MDP-LK-BP1 RCS-MDP-LK-BP2 CVC-P3AOP-P3BSTBY 1.9E-008 2.35 CVC-XHE-XM-ACOOL NOTSUMMER SWS-FAN-FS-2A SWS-FAN-FS-2B
/RCS-MDP-LK-BP1 RCS-MDP-LK-BP2 CVC-P3BOP-P3ASTBY 1.9E-008 2.35 CVC-XHE-XM-ACOOL NOTSUMMER SWS-FAN-FS-2A SWS-FAN-FS-2B
/RCS-MDP-LK-BP1 RCS-MDP-LK-BP2 2006/05/31 10:45:09 page 3
LER 423-2005-002 14 CVC-P3AOP-P3BSTBY 1.2E-008 1.56 CVC-XHE-XM-ACOOL SWS-XHE-XL-VENT SWS-FAN-CF-HVY2ABS /RCS-MDP-LK-BP1 RCS-MDP-LK-BP2 CVC-P3BOP-P3ASTBY 1.2E-008 1.56 CVC-XHE-XM-ACOOL SWS-XHE-XL-VENT SWS-FAN-CF-HVY2ABS /RCS-MDP-LK-BP1 RCS-MDP-LK-BP2 CVC-P3AOP-P3BSTBY Event Tree: TRANS CCDP: 5.5E-007 Sequence: 02-02-10 CCDP % Cut Set Cut Set Events 2.2E-007 38.90 CVC-XHE-XM-ACOOL NOTSUMMER
/SSC1 SWS-FAN-CF-HVY2ABS
/RCS-MDP-LK-BP1 RCS-MDP-LK-BP2 CVC-P3AOP-P3BSTBY 2.2E-007 38.90 CVC-XHE-XM-ACOOL NOTSUMMER
/SSC1 SWS-FAN-CF-HVY2ABS
/RCS-MDP-LK-BP1 RCS-MDP-LK-BP2 CVC-P3BOP-P3ASTBY 1.7E-008 3.11 CVC-XHE-XM-ACOOL NOTSUMMER SWS-PND-CF-23AB /SSC1
/RCS-MDP-LK-BP1 RCS-MDP-LK-BP2 CVC-P3AOP-P3BSTBY 1.7E-008 3.11 CVC-XHE-XM-ACOOL NOTSUMMER SWS-PND-CF-23AB /SSC1
/RCS-MDP-LK-BP1 RCS-MDP-LK-BP2 CVC-P3BOP-P3ASTBY 1.7E-008 3.09 CVC-XHE-XM-ACOOL NOTSUMMER SWS-FAN-CF-HVY2ABR /SSC1
/RCS-MDP-LK-BP1 RCS-MDP-LK-BP2 CVC-P3AOP-P3BSTBY 1.7E-008 3.09 CVC-XHE-XM-ACOOL NOTSUMMER SWS-FAN-CF-HVY2ABR /SSC1
/RCS-MDP-LK-BP1 RCS-MDP-LK-BP2 CVC-P3BOP-P3ASTBY 1.3E-008 2.35 CVC-XHE-XM-ACOOL NOTSUMMER
/SSC1 SWS-FAN-FS-2A SWS-FAN-FS-2B /RCS-MDP-LK-BP1 RCS-MDP-LK-BP2 CVC-P3AOP-P3BSTBY 1.3E-008 2.35 CVC-XHE-XM-ACOOL NOTSUMMER
/SSC1 SWS-FAN-FS-2A SWS-FAN-FS-2B /RCS-MDP-LK-BP1 RCS-MDP-LK-BP2 CVC-P3BOP-P3ASTBY 8.6E-009 1.56 CVC-XHE-XM-ACOOL SWS-XHE-XL-VENT
/SSC1 SWS-FAN-CF-HVY2ABS
/RCS-MDP-LK-BP1 RCS-MDP-LK-BP2 CVC-P3AOP-P3BSTBY 8.6E-009 1.56 CVC-XHE-XM-ACOOL SWS-XHE-XL-VENT
/SSC1 SWS-FAN-CF-HVY2ABS
/RCS-MDP-LK-BP1 RCS-MDP-LK-BP2 2006/05/31 10:45:09 page 4
LER 423-2005-002 15 CVC-P3BOP-P3ASTBY Event Tree: TRANS CCDP: 1.0E-007 Sequence: 19-08 CCDP % Cut Set Cut Set Events 3.2E-008 30.88 CVC-XHE-XM-BOR RPS-BME-CF-RTBAB 2.7E-008 25.76 RPS-XHE-XE-NSGNL CVC-XHE-XM-BOR RPS-CBI-CF-6OF8 /RPS-CCP-TM-CHA 2.4E-008 23.21 CVC-XHE-XM-BOR RPS-ROD-CF-RCCAS 1.8E-008 17.46 RPS-CCX-CF-6OF8 RPS-XHE-XE-NSGNL CVC-XHE-XM-BOR /RPS-CCP-TM-CHA 2.1E-009 1.99 CVC-XHE-XM-BOR RPS-UVL-CF-UVDAB RPS-XHE-XE-SIGNL Event Tree: TRANS CCDP: 9.2E-008 Sequence: 19-18 CCDP % Cut Set Cut Set Events 2.0E-008 22.09 RPS-BME-CF-RTBAB RCS-PHN-MODPOOR RCS-PHN-PL 1.7E-008 18.43 RPS-XHE-XE-NSGNL RCS-PHN-MODPOOR RCS-PHN-PL RPS-CBI-CF-6OF8
/RPS-CCP-TM-CHA 1.5E-008 16.61 RCS-PHN-MODPOOR RCS-PHN-PL RPS-ROD-CF-RCCAS 1.2E-008 12.49 RPS-CCX-CF-6OF8 RPS-XHE-XE-NSGNL RCS-PHN-MODPOOR RCS-PHN-PL
/RPS-CCP-TM-CHA 1.9E-009 2.10 RPS-BME-CF-RTBAB PPR-SRV-CC-SRV3 1.9E-009 2.10 RPS-BME-CF-RTBAB PPR-SRV-CC-SRV2 1.9E-009 2.10 RPS-BME-CF-RTBAB PPR-SRV-CC-SRV1 1.6E-009 1.76 RPS-XHE-XE-NSGNL RPS-CBI-CF-6OF8
/RPS-CCP-TM-CHA PPR-SRV-CC-SRV3 1.6E-009 1.76 RPS-XHE-XE-NSGNL RPS-CBI-CF-6OF8
/RPS-CCP-TM-CHA PPR-SRV-CC-SRV1 1.6E-009 1.76 RPS-XHE-XE-NSGNL RPS-CBI-CF-6OF8
/RPS-CCP-TM-CHA PPR-SRV-CC-SRV2 1.5E-009 1.58 RPS-ROD-CF-RCCAS PPR-SRV-CC-SRV2 1.5E-009 1.58 RPS-ROD-CF-RCCAS PPR-SRV-CC-SRV3 1.5E-009 1.58 RPS-ROD-CF-RCCAS PPR-SRV-CC-SRV1 1.3E-009 1.43 RCS-PHN-MODPOOR RCS-PHN-PL RPS-UVL-CF-UVDAB RPS-XHE-XE-SIGNL 1.1E-009 1.23 RPS-BME-CF-RTBAB PPR-SRV-CC-PRV2 1.1E-009 1.23 RPS-BME-CF-RTBAB PPR-SRV-CC-PRV1 1.1E-009 1.19 RPS-CCX-CF-6OF8 RPS-XHE-XE-NSGNL
/RPS-CCP-TM-CHA PPR-SRV-CC-SRV1 1.1E-009 1.19 RPS-CCX-CF-6OF8 RPS-XHE-XE-NSGNL
/RPS-CCP-TM-CHA PPR-SRV-CC-SRV2 1.1E-009 1.19 RPS-CCX-CF-6OF8 RPS-XHE-XE-NSGNL 2006/05/31 10:45:09 page 5
LER 423-2005-002 16
/RPS-CCP-TM-CHA PPR-SRV-CC-SRV3 9.4E-010 1.02 RPS-XHE-XE-NSGNL RPS-CBI-CF-6OF8
/RPS-CCP-TM-CHA PPR-SRV-CC-PRV1 9.4E-010 1.02 RPS-XHE-XE-NSGNL RPS-CBI-CF-6OF8
/RPS-CCP-TM-CHA PPR-SRV-CC-PRV2 BASIC EVENTS (Cut Sets Only)
Event Name Description Curr Prob AFW-AOV-CC-F083 CST ISOLATION VALVE 83 FAILS TO OPEN 9.0E-004 AFW-AOV-CC-F085 CST ISOLATION VALVE 85 FAILS TO OPEN 9.0E-004 AFW-MDP-CF-RUN AFW MDP FAILS TO RUN 5.9E-006 AFW-MDP-CF-START CCF OF AFW MDPS TO START 9.9E-005 AFW-MDP-FR-1A AFW MOTOR-DRIVEN PUMP FAILS TO RUN 5.2E-004 AFW-MDP-FR-1B AFW MOTOR-DRIVEN PUMP FAILS TO RUN 5.2E-004 AFW-MDP-FS-1A AFW MOTOR-DRIVEN PUMP 1A FAILS TO START 1.5E-003 AFW-MDP-FS-1B AFW MOTOR-DRIVEN PUMP 1B FAILS TO START 1.5E-003 AFW-MDP-TM-1A AFW MDP UNAVAILABLE DUE TO TEST AND MAINTENAN 5.0E-003 AFW-MDP-TM-1B AFW MDP UNAVAILABLE DUE TO TEST AND MAINTENAN 5.0E-003 AFW-PMP-FR-P1A AFW PUMPS FAIL TO RUN (EXCLUDING DRIVER) 4.0E-004 AFW-PMP-FR-P1B AFW PUMPS FAIL TO RUN (EXCLUDING DRIVER) 4.0E-004 AFW-TNK-FC-CST CST OR PUMP SUCTION PATH IS UNAVAILABLE 2.4E-006 AFW-TNK-FC-DWST DWST OR PUMP SUCTION PATH IS UNAVAILABLE 2.4E-006 CVC-P3AOP-P3BSTBY CHARGING PUMP 3A IN OPERATION WHILE PUMP 3B I 5.0E-001 CVC-P3BOP-P3ASTBY CHARGING PUMP 3B IN OPERATION WHILE PUMP 3A I 5.0E-001 CVC-XHE-XM-ACOOL OPERATOR FAILS TO ESTABLISH ALTERNATE PUMP CO 4.0E-002 CVC-XHE-XM-BOR OPERATOR FAILS TO INITIATE EMERGENCY BORATION 2.0E-002 HPI-XHE-XM-FB OPERATOR FAILS TO INITIATE FEED AND BLEED COO 2.0E-002 NOTSUMMER NOT SUMMER TIME OPERTION 7.5E-001 PPR-SRV-CC-PRV1 PORV 1 FAILS TO OPEN ON DEMAND 7.0E-004 PPR-SRV-CC-PRV2 PORV 2 FAILS TO OPEN ON DEMAND 7.0E-004 PPR-SRV-CC-SRV1 SAFETY RELIEF VALVE 1 FAILS TO OPEN ON HIGH P 1.2E-003 PPR-SRV-CC-SRV2 SAFETY RELIEF VALVE 1 FAILS TO OPEN ON HIGH P 1.2E-003 PPR-SRV-CC-SRV3 SAFETY RELIEF VALVE 1 FAILS TO OPEN ON HIGH P 1.2E-003 RCS-MDP-LK-BP1 RCP SEAL STAGE 1 INTEGRITY (BINDING/POPPING O 1.3E-002 RCS-MDP-LK-BP2 RCP SEAL STAGE 2 INTEGRITY (BINDING/POPPING O 2.0E-001 RCS-PHN-MODPOOR MODERATOR TEMP COEFFICIENT NOT ENOUGH NEGATIV 1.4E-002 RCS-PHN-PL POWER AT HIGH LEVEL 9.0E-001 RPS-BME-CF-RTBAB CCF OF RTB-A AND RTB-B (MECHANICAL) 1.6E-006 RPS-CBI-CF-6OF8 CCF 6 BISTABLES IN 3 OF 4 CHANNELS 2.7E-006 RPS-CCP-TM-CHA CH-A IN T&M 5.0E-003 RPS-CCX-CF-6OF8 CCF 6 ANALOG PROCESS LOGIC MODULES IN 3 OF 4 1.8E-006 RPS-ROD-CF-RCCAS CCF 10 OR MORE RCCAS FAIL TO DROP 1.2E-006 RPS-UVL-CF-UVDAB CCF UV DRIVERS TRAINS A AND B (2 0F 2) 1.0E-005 RPS-XHE-XE-NSGNL OPERATOR FAILS TO RESPOND WITH NO RPS SIGNAL 5.0E-001 RPS-XHE-XE-SIGNL OPERATOR FAILS TO RESPOND WITH RPS SIGNAL PRE 1.0E-002 SSC1 RCS COOLDOWN (POST-LOCA) 3.0E-001 SWS-FAN-CF-HVY2ABR CCF OF SWS VENTILLATION FANS TO RUN 8.2E-006 SWS-FAN-CF-HVY2ABS CCF OF SWS VENTILLATION FANS TO START 1.0E-004 SWS-FAN-FS-2A SWS FAN HVY-2A FAILS TO START 2.5E-003 2006/05/31 10:45:09 page 6
LER 423-2005-002 17 Event Name Description Curr Prob SWS-FAN-FS-2B SWS FAN HVY-2B FAILS TO START 2.5E-003 SWS-PND-CF-23AB CCF O SWS VENTILLATION AODS TO OPEN 8.3E-006 SWS-XHE-XL-VENT OPERATOR FAILS TO PROVIDE ALTERNATE VENTILATI 3.0E-002 2006/05/31 10:45:09 page 7
LER 423-2005-002 18 I N I T I A T I N G E V E N T A S S E S S M E N T Code Ver : 7:26 Fam : MIL3_3 Model Ver : 2005/10/28 User : INEEL Init Event: IE-SLOCA Ev ID: SLOCA-TDP-LIC Total CCDP: 1.1E-003 Desc : SLOCA CCDP with licensee HEP for HPR - no TDP BASIC EVENT CHANGES Event Name Description Base Prob Curr Prob Type AFW-TDP-TM-P2 FEED PUMP P2 IS IN TEST OR M 5.0E-003 1.0E+000 TRUE HPR-XHE-XM-RECIRC OPERATOR FAILS TO START HIGH 5.0E-003 1.1E-004 IE-LLOCA LARGE LOSS OF COOLANT ACCIDE 5.0E-006 +0.0E+000 IE-LOCCW LOSS OF COMPONENT COOLING WA 4.0E-004 +0.0E+000 IE-LOCHS LOSS ODF CONDENSER HEAT SINK 9.0E-002 +0.0E+000 IE-LODCA LOSS OF DC BUS 301-A INITIAT 1.3E-003 +0.0E+000 IE-LODCB LOSS OF DC BUS 301-B INITIAT 1.3E-003 +0.0E+000 IE-LOMFW LOSS OF MAIN FEEDWATER INITI 1.0E-001 +0.0E+000 IE-LOOP LOSS OF OFFSITE POWER 3.6E-002 +0.0E+000 IE-LOSWS LOSS OF SERVICE WATER 4.0E-004 +0.0E+000 IE-MLOCA MEDIUM LOSS OF COOLANT ACCI 4.0E-005 +0.0E+000 IE-RHR-CLDIS-V RHR COLD LEG DISCHARGE ISLO +0.0E+000 +0.0E+000 IE-RHR-HLDIS-V RHR HOT LEG DISCHARGE ISLOCA +0.0E+000 +0.0E+000 IE-RHR-SUC-V RHR SUCTION LINE ISLOCA EVEN +0.0E+000 +0.0E+000 IE-SGTR STEAM GENERATOR TUBE RUPTURE 4.0E-003 +0.0E+000 IE-SI-CLDIS-V SI COLD LEG DISCHARGE ISLOC +0.0E+000 +0.0E+000 IE-SI-HLDIS-V SI HOT LEG DISCHARGE ISLOCA +0.0E+000 +0.0E+000 IE-SLOCA SMALL LOSS OF COOLANT ACCIDE 4.0E-004 1.0E+000 IE-TRANS TRANSIENT 7.0E-001 +0.0E+000 SEQUENCE PROBABILITIES Truncation : Cummulative : 100.0% Individual : 0.0%
Event Tree Name Sequence Name CCDP %Cont SLOCA 03 1.1E-003 SLOCA 07 5.6E-005 SLOCA 12 7.7E-006 SLOCA 10 5.4E-006 SLOCA 22 5.2E-006 SLOCA 21 3.7E-006 SLOCA 05 2.8E-006 SLOCA 16 4.5E-007 SLOCA 15 2.8E-007 SLOCA 11 2.2E-007 SLOCA 20 6.2E-008 SLOCA 18 5.6E-009 2006/05/31 13:15:02 page 1
LER 423-2005-002 19 SLOCA 09 2.9E-011 SEQUENCE LOGIC Event Tree Sequence Name Logic SLOCA 03 /RPS /AFW
/HPI /SSC
/PZR RHR HPR SLOCA 07 /RPS /AFW
/HPI SSC HPR SLOCA 12 /RPS /AFW HPI SSC1 SLOCA 10 /RPS /AFW HPI /SSC1
/PZR1 LPI SLOCA 22 RPS SLOCA 21 /RPS AFW FAB SLOCA 05 /RPS /AFW
/HPI /SSC PZR HPR SLOCA 16 /RPS AFW
/FAB /SSCR
/SSC PZR SLOCA 15 /RPS AFW
/FAB /SSCR
/SSC /PZR RHR HPR SLOCA 11 /RPS /AFW HPI /SSC1 PZR1 SLOCA 20 /RPS AFW
/FAB SSCR HPR SLOCA 18 /RPS AFW
/FAB /SSCR SSC HPR SLOCA 09 /RPS /AFW 2006/05/31 13:15:02 page 2
LER 423-2005-002 20 HPI /SSC1
/PZR1 /LPI LPR Fault Tree Name Description AFW AUXILIARY FEEDWATER FAB FEED AND BLEED HPI HIGH PRESSURE INJECTION HPR HIGH PRESSURE RECIRC LPI LOW PRESSURE INJECTION LPR LOW PRESSURE RECIRC PZR RCS DEPRESS FOR LPI/RHR PZR1 RCS DEPRESS FOR LPI/RHR RHR RESIDUAL HEAT REMOVAL RPS REACTOR TRIP SSC SECONDARY SIDE COOLING SSC1 RCS COOLDOWN (POST-LOCA)
SSCR SECONDARY SIDE COOLING RECOVERY SEQUENCE CUT SETS Truncation: Cummulative: 100.0% Individual: 1.0%
Event Tree: SLOCA CCDP: 1.1E-003 Sequence: 03 CCDP % Cut Set Cut Set Events 2.8E-004 26.56 LPI-ICC-FC-MINFLO 2.0E-004 18.97 RHR-XVM-CO-V43 1.1E-004 10.43 HPR-XHE-XM-RECIRC 7.8E-005 7.36 NOTSUMMER SWS-FAN-CF-HVY2ABS 4.1E-005 3.87 CVC-MOV-CF-MINFL 2.7E-005 2.58 RSS-MOV-CF-LPSI 2.6E-005 2.48 LPI-MOV-CF-8804AB 2.5E-005 2.37 RSS-MDP-TM-P1A RSS-MDP-TM-P1B RSS-XHE-XM-P1C RSS-XHE-XM-P1D Event Tree: SLOCA CCDP: 5.6E-005 Sequence: 07 CCDP % Cut Set Cut Set Events 5.5E-005 98.01 SSC-XHE-XM-CDOWN HPR-XHE-XM-RECIRC1 2006/05/31 13:15:02 page 3
LER 423-2005-002 21 Event Tree: SLOCA CCDP: 7.7E-006 Sequence: 12 CCDP % Cut Set Cut Set Events 2.4E-006 31.21 HPI-TNK-FC-RWST 1.6E-006 20.19 CVC-XHE-XM-ACOOL NOTSUMMER SWS-FAN-CF-HVY2ABS CVC-P3BOP-P3ASTBY 1.6E-006 20.19 CVC-XHE-XM-ACOOL NOTSUMMER SWS-FAN-CF-HVY2ABS CVC-P3AOP-P3BSTBY 2.1E-007 2.68 CVC-XHE-XM-ACOOL SWS-MOV-CF-50AB CVC-P3BOP-P3ASTBY 2.1E-007 2.68 CVC-XHE-XM-ACOOL SWS-MOV-CF-71AB CVC-P3BOP-P3ASTBY 2.1E-007 2.68 CVC-XHE-XM-ACOOL SWS-MOV-CF-50AB CVC-P3AOP-P3BSTBY 2.1E-007 2.68 CVC-XHE-XM-ACOOL SWS-MOV-CF-71AB CVC-P3AOP-P3BSTBY 1.2E-007 1.61 CVC-XHE-XM-ACOOL NOTSUMMER SWS-PND-CF-23AB CVC-P3AOP-P3BSTBY 1.2E-007 1.61 CVC-XHE-XM-ACOOL NOTSUMMER SWS-PND-CF-23AB CVC-P3BOP-P3ASTBY 1.2E-007 1.60 CVC-XHE-XM-ACOOL NOTSUMMER SWS-FAN-CF-HVY2ABR CVC-P3AOP-P3BSTBY 1.2E-007 1.60 CVC-XHE-XM-ACOOL NOTSUMMER SWS-FAN-CF-HVY2ABR CVC-P3BOP-P3ASTBY 9.6E-008 1.25 ACP-BAC-LP-34C CVC-XHE-XM-ACOOL CVC-P3BOP-P3ASTBY 9.6E-008 1.25 ACP-BAC-LP-34C CVC-XHE-XM-ACOOL CVC-P3AOP-P3BSTBY 9.4E-008 1.22 CVC-XHE-XM-ACOOL NOTSUMMER SWS-FAN-FS-2A SWS-FAN-FS-2B CVC-P3AOP-P3BSTBY 9.4E-008 1.22 CVC-XHE-XM-ACOOL NOTSUMMER SWS-FAN-FS-2A SWS-FAN-FS-2B CVC-P3BOP-P3ASTBY Event Tree: SLOCA CCDP: 5.4E-006 Sequence: 10 CCDP % Cut Set Cut Set Events 1.7E-006 31.40 HPI-TNK-FC-RWST /SSC1 1.1E-006 20.31 CVC-XHE-XM-ACOOL NOTSUMMER
/SSC1 SWS-FAN-CF-HVY2ABS CVC-P3BOP-P3ASTBY 1.1E-006 20.31 CVC-XHE-XM-ACOOL NOTSUMMER
/SSC1 SWS-FAN-CF-HVY2ABS CVC-P3AOP-P3BSTBY 1.4E-007 2.69 CVC-XHE-XM-ACOOL SWS-MOV-CF-50AB
/SSC1 CVC-P3BOP-P3ASTBY 2006/05/31 13:15:02 page 4
LER 423-2005-002 22 1.4E-007 2.69 CVC-XHE-XM-ACOOL SWS-MOV-CF-71AB
/SSC1 CVC-P3BOP-P3ASTBY 1.4E-007 2.69 CVC-XHE-XM-ACOOL SWS-MOV-CF-50AB
/SSC1 CVC-P3AOP-P3BSTBY 1.4E-007 2.69 CVC-XHE-XM-ACOOL SWS-MOV-CF-71AB
/SSC1 CVC-P3AOP-P3BSTBY 8.7E-008 1.62 CVC-XHE-XM-ACOOL NOTSUMMER SWS-PND-CF-23AB /SSC1 CVC-P3BOP-P3ASTBY 8.7E-008 1.62 CVC-XHE-XM-ACOOL NOTSUMMER SWS-PND-CF-23AB /SSC1 CVC-P3AOP-P3BSTBY 8.6E-008 1.61 CVC-XHE-XM-ACOOL NOTSUMMER SWS-FAN-CF-HVY2ABR /SSC1 CVC-P3BOP-P3ASTBY 8.6E-008 1.61 CVC-XHE-XM-ACOOL NOTSUMMER SWS-FAN-CF-HVY2ABR /SSC1 CVC-P3AOP-P3BSTBY 6.7E-008 1.26 ACP-BAC-LP-34C CVC-XHE-XM-ACOOL
/SSC1 CVC-P3BOP-P3ASTBY 6.7E-008 1.26 ACP-BAC-LP-34C CVC-XHE-XM-ACOOL
/SSC1 CVC-P3AOP-P3BSTBY 6.6E-008 1.23 CVC-XHE-XM-ACOOL NOTSUMMER
/SSC1 SWS-FAN-FS-2A SWS-FAN-FS-2B CVC-P3BOP-P3ASTBY 6.6E-008 1.23 CVC-XHE-XM-ACOOL NOTSUMMER
/SSC1 SWS-FAN-FS-2A SWS-FAN-FS-2B CVC-P3AOP-P3BSTBY Event Tree: SLOCA CCDP: 5.2E-006 Sequence: 22 CCDP % Cut Set Cut Set Events 1.6E-006 30.88 RPS-BME-CF-RTBAB 1.3E-006 25.76 RPS-XHE-XE-NSGNL RPS-CBI-CF-6OF8
/RPS-CCP-TM-CHA 1.2E-006 23.21 RPS-ROD-CF-RCCAS 9.1E-007 17.46 RPS-CCX-CF-6OF8 RPS-XHE-XE-NSGNL
/RPS-CCP-TM-CHA 1.0E-007 1.99 RPS-UVL-CF-UVDAB RPS-XHE-XE-SIGNL Event Tree: SLOCA CCDP: 3.7E-006 Sequence: 21 CCDP % Cut Set Cut Set Events 2.0E-006 53.50 HPI-XHE-XM-FB AFW-MDP-CF-START 1.5E-007 4.05 HPI-XHE-XM-FB AFW-MDP-TM-1A AFW-MDP-FS-1B 1.5E-007 4.05 HPI-XHE-XM-FB AFW-MDP-FS-1A AFW-MDP-TM-1B 2006/05/31 13:15:02 page 5
LER 423-2005-002 23 1.2E-007 3.17 HPI-XHE-XM-FB AFW-MDP-CF-RUN 9.0E-008 2.43 HPI-XHE-XM-FB AFW-AOV-CC-F083 AFW-MDP-TM-1A 9.0E-008 2.43 HPI-XHE-XM-FB AFW-AOV-CC-F085 AFW-MDP-TM-1B 6.9E-008 1.87 AFW-MDP-CF-START PPR-SRV-CC-PRV1 6.9E-008 1.87 PPR-SRV-CC-PRV2 AFW-MDP-CF-START 5.2E-008 1.39 HPI-XHE-XM-FB AFW-MDP-TM-1A AFW-MDP-FR-1B 5.2E-008 1.39 HPI-XHE-XM-FB AFW-MDP-FR-1A AFW-MDP-TM-1B 4.8E-008 1.30 HPI-XHE-XM-FB AFW-TNK-FC-CST 4.8E-008 1.30 HPI-XHE-XM-FB AFW-TNK-FC-DWST 4.5E-008 1.21 HPI-XHE-XM-FB AFW-MDP-FS-1A AFW-MDP-FS-1B 4.0E-008 1.08 HPI-XHE-XM-FB AFW-PMP-FR-P1B AFW-MDP-TM-1A 4.0E-008 1.08 AFW-PMP-FR-P1A HPI-XHE-XM-FB AFW-MDP-TM-1B Event Tree: SLOCA CCDP: 2.8E-006 Sequence: 05 CCDP % Cut Set Cut Set Events 2.8E-007 10.03 LPI-ICC-FC-MINFLO RCS-XHE-RCSDEP 2.2E-007 8.03 LPI-ICC-FC-MINFLO RCS-SOV-CC-AUXSPRAY 2.2E-007 8.03 LPI-ICC-FC-MINFLO RCS-SOV-CC-SPRAY 2.0E-007 7.17 RCS-XHE-RCSDEP RHR-XVM-CO-V43 1.6E-007 5.73 RCS-SOV-CC-AUXSPRAY RHR-XVM-CO-V43 1.6E-007 5.73 RCS-SOV-CC-SPRAY RHR-XVM-CO-V43 1.1E-007 3.94 RCS-XHE-RCSDEP HPR-XHE-XM-RECIRC 8.8E-008 3.15 RCS-SOV-CC-AUXSPRAY HPR-XHE-XM-RECIRC 8.8E-008 3.15 RCS-SOV-CC-SPRAY HPR-XHE-XM-RECIRC 7.8E-008 2.78 NOTSUMMER RCS-XHE-RCSDEP SWS-FAN-CF-HVY2ABS 6.2E-008 2.22 NOTSUMMER RCS-SOV-CC-SPRAY SWS-FAN-CF-HVY2ABS 6.2E-008 2.22 NOTSUMMER RCS-SOV-CC-AUXSPRAY SWS-FAN-CF-HVY2ABS 4.1E-008 1.46 RCS-XHE-RCSDEP CVC-MOV-CF-MINFL 3.3E-008 1.17 RCS-SOV-CC-AUXSPRAY CVC-MOV-CF-MINFL 3.3E-008 1.17 RCS-SOV-CC-SPRAY CVC-MOV-CF-MINFL Event Tree: SLOCA CCDP: 4.5E-007 Sequence: 16 CCDP % Cut Set Cut Set Events 9.9E-008 22.18 AFW-MDP-CF-START RCS-XHE-RCSDEP 7.9E-008 17.74 AFW-MDP-CF-START RCS-SOV-CC-SPRAY 7.9E-008 17.74 AFW-MDP-CF-START RCS-SOV-CC-AUXSPRAY 2006/05/31 13:15:02 page 6
LER 423-2005-002 24 7.5E-009 1.68 AFW-MDP-FS-1A AFW-MDP-TM-1B RCS-XHE-RCSDEP 7.5E-009 1.68 AFW-MDP-TM-1A AFW-MDP-FS-1B RCS-XHE-RCSDEP 6.0E-009 1.34 AFW-MDP-FS-1A AFW-MDP-TM-1B RCS-SOV-CC-AUXSPRAY 6.0E-009 1.34 AFW-MDP-TM-1A AFW-MDP-FS-1B RCS-SOV-CC-AUXSPRAY 6.0E-009 1.34 AFW-MDP-TM-1A AFW-MDP-FS-1B RCS-SOV-CC-SPRAY 6.0E-009 1.34 AFW-MDP-FS-1A AFW-MDP-TM-1B RCS-SOV-CC-SPRAY 5.9E-009 1.31 AFW-MDP-CF-RUN RCS-XHE-RCSDEP 4.7E-009 1.06 PPR-SRV-CF-PORVS AFW-MDP-CF-START 4.7E-009 1.05 AFW-MDP-CF-RUN RCS-SOV-CC-SPRAY 4.7E-009 1.05 AFW-MDP-CF-RUN RCS-SOV-CC-AUXSPRAY 4.5E-009 1.01 AFW-AOV-CC-F085 AFW-MDP-TM-1B RCS-XHE-RCSDEP 4.5E-009 1.01 AFW-AOV-CC-F083 AFW-MDP-TM-1A RCS-XHE-RCSDEP Event Tree: SLOCA CCDP: 2.8E-007 Sequence: 15 CCDP % Cut Set Cut Set Events 2.8E-008 9.94 LPI-ICC-FC-MINFLO AFW-MDP-CF-START 2.4E-008 8.59 ACP-BAC-LP-34C AFW-MDP-TM-1B 2.0E-008 7.10 AFW-MDP-CF-START RHR-XVM-CO-V43 1.2E-008 4.29 ACP-BAC-LP-34D ESF-FAN-FS-5A 1.2E-008 4.29 ACP-BAC-LP-34D ESF-FAN-FS-6A 1.1E-008 3.90 AFW-MDP-CF-START HPR-XHE-XM-RECIRC 7.7E-009 2.75 AFW-MDP-CF-START NOTSUMMER SWS-FAN-CF-HVY2ABS 7.2E-009 2.58 ACP-BAC-LP-34C AFW-MDP-FS-1B 4.3E-009 1.55 ACP-BAC-LP-34C AFW-AOV-CC-F083 4.0E-009 1.45 AFW-MDP-CF-START CVC-MOV-CF-MINFL Event Tree: SLOCA CCDP: 2.2E-007 Sequence: 11 CCDP % Cut Set Cut Set Events 6.7E-008 30.01 RCS-XHE-RCSDEP1 HPI-TNK-FC-RWST
/SSC1 4.4E-008 19.41 RCS-XHE-RCSDEP1 CVC-XHE-XM-ACOOL NOTSUMMER /SSC1 SWS-FAN-CF-HVY2ABS CVC-P3BOP-P3ASTBY 4.4E-008 19.41 RCS-XHE-RCSDEP1 CVC-XHE-XM-ACOOL NOTSUMMER /SSC1 SWS-FAN-CF-HVY2ABS CVC-P3AOP-P3BSTBY 5.8E-009 2.58 RCS-XHE-RCSDEP1 CVC-XHE-XM-ACOOL 2006/05/31 13:15:02 page 7
LER 423-2005-002 25 SWS-MOV-CF-50AB /SSC1 CVC-P3AOP-P3BSTBY 5.8E-009 2.58 RCS-XHE-RCSDEP1 CVC-XHE-XM-ACOOL SWS-MOV-CF-71AB /SSC1 CVC-P3AOP-P3BSTBY 5.8E-009 2.58 RCS-XHE-RCSDEP1 CVC-XHE-XM-ACOOL SWS-MOV-CF-71AB /SSC1 CVC-P3BOP-P3ASTBY 5.8E-009 2.58 RCS-XHE-RCSDEP1 CVC-XHE-XM-ACOOL SWS-MOV-CF-50AB /SSC1 CVC-P3BOP-P3ASTBY 3.5E-009 1.55 RCS-XHE-RCSDEP1 CVC-XHE-XM-ACOOL NOTSUMMER SWS-PND-CF-23AB
/SSC1 CVC-P3BOP-P3ASTBY 3.5E-009 1.55 RCS-XHE-RCSDEP1 CVC-XHE-XM-ACOOL NOTSUMMER SWS-PND-CF-23AB
/SSC1 CVC-P3AOP-P3BSTBY 3.5E-009 1.54 RCS-XHE-RCSDEP1 CVC-XHE-XM-ACOOL NOTSUMMER SWS-FAN-CF-HVY2ABR
/SSC1 CVC-P3BOP-P3ASTBY 3.5E-009 1.54 RCS-XHE-RCSDEP1 CVC-XHE-XM-ACOOL NOTSUMMER SWS-FAN-CF-HVY2ABR
/SSC1 CVC-P3AOP-P3BSTBY 2.7E-009 1.20 ACP-BAC-LP-34C RCS-XHE-RCSDEP1 CVC-XHE-XM-ACOOL /SSC1 CVC-P3AOP-P3BSTBY 2.7E-009 1.20 ACP-BAC-LP-34C RCS-XHE-RCSDEP1 CVC-XHE-XM-ACOOL /SSC1 CVC-P3BOP-P3ASTBY 2.6E-009 1.17 RCS-XHE-RCSDEP1 CVC-XHE-XM-ACOOL NOTSUMMER /SSC1 SWS-FAN-FS-2A SWS-FAN-FS-2B CVC-P3AOP-P3BSTBY 2.6E-009 1.17 RCS-XHE-RCSDEP1 CVC-XHE-XM-ACOOL NOTSUMMER /SSC1 SWS-FAN-FS-2A SWS-FAN-FS-2B CVC-P3BOP-P3ASTBY Event Tree: SLOCA CCDP: 6.2E-008 Sequence: 20 CCDP % Cut Set Cut Set Events 5.6E-009 9.00 PCS-XHE-XO-SEC LPI-ICC-FC-MINFLO AFW-MDP-CF-START 4.8E-009 7.78 ACP-BAC-LP-34C PCS-XHE-XO-SEC AFW-MDP-TM-1B 4.0E-009 6.43 PCS-XHE-XO-SEC AFW-MDP-CF-START RHR-XVM-CO-V43 2.4E-009 3.89 ACP-BAC-LP-34D PCS-XHE-XO-SEC ESF-FAN-FS-6A 2.4E-009 3.89 ACP-BAC-LP-34D PCS-XHE-XO-SEC 2006/05/31 13:15:02 page 8
LER 423-2005-002 26 ESF-FAN-FS-5A 2.4E-009 3.89 ACP-BAC-LP-34C PPR-SRV-OO-WTR1 AFW-MDP-TM-1B 2.2E-009 3.54 PCS-XHE-XO-SEC AFW-MDP-CF-START HPR-XHE-XM-RECIRC 1.5E-009 2.49 PCS-XHE-XO-SEC AFW-MDP-CF-START NOTSUMMER SWS-FAN-CF-HVY2ABS 1.4E-009 2.33 ACP-BAC-LP-34C PCS-XHE-XO-SEC AFW-MDP-FS-1B 1.2E-009 1.94 ACP-BAC-LP-34D PPR-SRV-OO-WTR2 ESF-FAN-FS-5A 1.2E-009 1.94 ACP-BAC-LP-34D PPR-SRV-OO-WTR2 ESF-FAN-FS-6A 8.6E-010 1.40 ACP-BAC-LP-34C PCS-XHE-XO-SEC AFW-AOV-CC-F083 8.1E-010 1.31 PCS-XHE-XO-SEC AFW-MDP-CF-START CVC-MOV-CF-MINFL 7.2E-010 1.17 ACP-BAC-LP-34C PPR-SRV-OO-WTR1 AFW-MDP-FS-1B Event Tree: SLOCA CCDP: 5.6E-009 Sequence: 18 CCDP % Cut Set Cut Set Events 5.4E-009 97.26 SSC-XHE-XM-CDOWN AFW-MDP-CF-START HPR-XHE-XM-RECIRC1 Event Tree: SLOCA CCDP: 2.9E-011 Sequence: 09 CCDP % Cut Set Cut Set Events 4.7E-012 16.08 CVC-CKV-CC-DISCH /SSC1 HPI-MDP-CF-START LPR-XHE-XM-ERROR 1.8E-012 5.94 SWS-MOV-OO-50A CVC-CKV-CC-DISCH RSS-MDP-TM-P1B RSS-XHE-XM-P1D
/SSC1 HPI-MDP-TM-P1B 1.8E-012 5.94 CVC-CKV-CC-DISCH RSS-MDP-TM-P1B SWS-MOV-OO-71A RSS-XHE-XM-P1D
/SSC1 HPI-MDP-TM-P1B 1.8E-012 5.94 SWS-MOV-OO-50A CCE-MDP-TM-P1B RSS-MDP-TM-P1B CVC-XHE-XM-ACOOL RSS-XHE-XM-P1D /SSC1 HPI-MDP-TM-P1B CVC-P3AOP-P3BSTBY 1.8E-012 5.94 CCE-MDP-TM-P1B RSS-MDP-TM-P1B CVC-XHE-XM-ACOOL SWS-MOV-OO-71A RSS-XHE-XM-P1D /SSC1 HPI-MDP-TM-P1B CVC-P3AOP-P3BSTBY 1.8E-012 5.94 SWS-MOV-OO-50A RSS-MDP-TM-P1B CVC-MDP-TM-P3B CVC-XHE-XM-ACOOL RSS-XHE-XM-P1D /SSC1 2006/05/31 13:15:02 page 9
LER 423-2005-002 27 HPI-MDP-TM-P1B CVC-P3AOP-P3BSTBY 1.8E-012 5.94 RSS-MDP-TM-P1B CVC-MDP-TM-P3B CVC-XHE-XM-ACOOL SWS-MOV-OO-71A RSS-XHE-XM-P1D /SSC1 HPI-MDP-TM-P1B CVC-P3AOP-P3BSTBY 1.8E-012 5.94 CVC-CKV-CC-DISCH RSS-MDP-TM-P1A SWS-MOV-OO-50B RSS-XHE-XM-P1C
/SSC1 HPI-MDP-TM-P1A 1.8E-012 5.94 CVC-CKV-CC-DISCH RSS-MDP-TM-P1A SWS-MOV-OO-71B RSS-XHE-XM-P1C
/SSC1 HPI-MDP-TM-P1A 1.8E-012 5.94 RSS-MDP-TM-P1A CVC-XHE-XM-ACOOL SWS-MOV-OO-50B RSS-XHE-XM-P1C
/SSC1 HPI-MDP-TM-P1A CVC-P3BOP-P3ASTBY CCE-MDP-TM-P1A 1.8E-012 5.94 RSS-MDP-TM-P1A CVC-XHE-XM-ACOOL SWS-MOV-OO-71B RSS-XHE-XM-P1C
/SSC1 HPI-MDP-TM-P1A CVC-P3BOP-P3ASTBY CCE-MDP-TM-P1A 1.8E-012 5.94 RSS-MDP-TM-P1A CVC-XHE-XM-ACOOL SWS-MOV-OO-50B RSS-XHE-XM-P1C
/SSC1 HPI-MDP-TM-P1A CVC-MDP-TM-P3A CVC-P3BOP-P3ASTBY 1.8E-012 5.94 RSS-MDP-TM-P1A CVC-XHE-XM-ACOOL SWS-MOV-OO-71B RSS-XHE-XM-P1C
/SSC1 HPI-MDP-TM-P1A CVC-MDP-TM-P3A CVC-P3BOP-P3ASTBY 1.2E-012 4.20 CVC-MOV-CF-SUCT /SSC1 HPI-MDP-CF-START LPR-XHE-XM-ERROR 1.2E-012 4.20 CVC-MOV-CF-VCT /SSC1 HPI-MDP-CF-START LPR-XHE-XM-ERROR 1.2E-012 4.20 /SSC1 CVC-MOV-CF-DISCH HPI-MDP-CF-START LPR-XHE-XM-ERROR BASIC EVENTS (Cut Sets Only)
Event Name Description Curr Prob ACP-BAC-LP-34C 4160 VAC BUS 34C FAILS 4.8E-006 ACP-BAC-LP-34D 4160 VAC BUS 34D FAILS 4.8E-006 AFW-AOV-CC-F083 CST ISOLATION VALVE 83 FAILS TO OPEN 9.0E-004 AFW-AOV-CC-F085 CST ISOLATION VALVE 85 FAILS TO OPEN 9.0E-004 AFW-MDP-CF-RUN AFW MDP FAILS TO RUN 5.9E-006 AFW-MDP-CF-START CCF OF AFW MDPS TO START 9.9E-005 AFW-MDP-FR-1A AFW MOTOR-DRIVEN PUMP FAILS TO RUN 5.2E-004 AFW-MDP-FR-1B AFW MOTOR-DRIVEN PUMP FAILS TO RUN 5.2E-004 AFW-MDP-FS-1A AFW MOTOR-DRIVEN PUMP 1A FAILS TO START 1.5E-003 AFW-MDP-FS-1B AFW MOTOR-DRIVEN PUMP 1B FAILS TO START 1.5E-003 AFW-MDP-TM-1A AFW MDP UNAVAILABLE DUE TO TEST AND MAINTENAN 5.0E-003 AFW-MDP-TM-1B AFW MDP UNAVAILABLE DUE TO TEST AND MAINTENAN 5.0E-003 AFW-PMP-FR-P1A AFW PUMPS FAIL TO RUN (EXCLUDING DRIVER) 4.0E-004 2006/05/31 13:15:02 page 10
LER 423-2005-002 28 Event Name Description Curr Prob AFW-PMP-FR-P1B AFW PUMPS FAIL TO RUN (EXCLUDING DRIVER) 4.0E-004 AFW-TNK-FC-CST CST OR PUMP SUCTION PATH IS UNAVAILABLE 2.4E-006 AFW-TNK-FC-DWST DWST OR PUMP SUCTION PATH IS UNAVAILABLE 2.4E-006 CCE-MDP-TM-P1A CCE MDP P1A UNAVAILABLE DUE TO TEST AND MAINT 5.0E-003 CCE-MDP-TM-P1B CCE MDP P1B UNAVAILABLE DUE TO TEST AND MAINT 5.0E-003 CVC-CKV-CC-DISCH CHARGING DISCHARGE CKV 8815 FAILS TO OPEN 1.0E-004 CVC-MDP-TM-P3A PUMP P3A IS IN TEST OR MAINTENANCE 5.0E-003 CVC-MDP-TM-P3B PUMP P3B IS IN TEST OR MAINTENANCE 5.0E-003 CVC-MOV-CF-DISCH COMMON CAUSE FAILURE OF DISCHARGE MOVS 2.6E-005 CVC-MOV-CF-MINFL CCF OF CVC/RWST MINFLOW VALVES TO CLOSE 8511A 4.1E-005 CVC-MOV-CF-SUCT CCF OF CVC SUCTION MOVS CV112D/E 2.6E-005 CVC-MOV-CF-VCT COMMON CAUSE FAILURE OF VCT MOVS 2.6E-005 CVC-P3AOP-P3BSTBY CHARGING PUMP 3A IN OPERATION WHILE PUMP 3B I 5.0E-001 CVC-P3BOP-P3ASTBY CHARGING PUMP 3B IN OPERATION WHILE PUMP 3A I 5.0E-001 CVC-XHE-XM-ACOOL OPERATOR FAILS TO ESTABLISH ALTERNATE PUMP CO 4.0E-002 ESF-FAN-FS-5A AFW SUPPLY FAN 5A FAILS TO START 2.5E-003 ESF-FAN-FS-6A AFW EXHAUST FAN 6A FAILS TO START 2.5E-003 HPI-MDP-CF-START HPI PUMPS FAIL FROM COMMON CAUSE TO START 6.8E-005 HPI-MDP-TM-P1A HPI PUMP TRAIN P1A IS IN TEST OR MAINTENANCE 5.0E-003 HPI-MDP-TM-P1B HPI PUMP TRAIN P1B IS IN TEST OR MAINTENANCE 5.0E-003 HPI-TNK-FC-RWST RWST IS UNAVAILABLE 2.4E-006 HPI-XHE-XM-FB OPERATOR FAILS TO INITIATE FEED AND BLEED COO 2.0E-002 HPR-XHE-XM-RECIRC OPERATOR FAILS TO START HIGH PRESSURE RECIRC 1.1E-004 HPR-XHE-XM-RECIRC1 OPERATOR FAILS TO START HIGH PRESSURE RECIRC 5.5E-002 LPI-ICC-FC-MINFLO MINFLOW VALVE 8511A,B OR 8512A,B INTERLOCKS F 2.8E-004 LPI-MOV-CF-8804AB LPSI TO SI VALVES 8804A,B FAIL FROM COMMON CA 2.6E-005 LPR-XHE-XM-ERROR OPERATOR FAILS TO INITIATE LOW PRESSURE RECIR 1.0E-003 NOTSUMMER NOT SUMMER TIME OPERTION 7.5E-001 PCS-XHE-XO-SEC OPERATOR FAILS TO ESTABLISH SECONDARY COOLING 2.0E-001 PPR-SRV-CC-PRV1 PORV 1 FAILS TO OPEN ON DEMAND 7.0E-004 PPR-SRV-CC-PRV2 PORV 2 FAILS TO OPEN ON DEMAND 7.0E-004 PPR-SRV-CF-PORVS CCF OF PORVS TO OPEN 4.8E-005 PPR-SRV-OO-WTR1 PORV 1 FAILS TO RECLOSE AFTER PASSING WATER 1.0E-001 PPR-SRV-OO-WTR2 PORV 2 FAILS TO RECLOSE AFTER PASSING WATER 1.0E-001 RCS-SOV-CC-AUXSPRAY PRESSURIZER AUX SPRAY VALVE FAILS TO OPEN 8.0E-004 RCS-SOV-CC-SPRAY PRESSURIZER SPRAY VALVE FAILS TO OPEN 8.0E-004 RCS-XHE-RCSDEP OPERATOR FAILS TO DEPRESSURIZE THE RCS 1.0E-003 RCS-XHE-RCSDEP1 OPERATOR FAILS TO RAPIDLY DEPRESSURIZE THE RC 4.0E-002 RHR-XVM-CO-V43 RHR MANUAL VALVE V43 MISALIGNED OPEN (PSA PRO 2.0E-004 RPS-BME-CF-RTBAB CCF OF RTB-A AND RTB-B (MECHANICAL) 1.6E-006 RPS-CBI-CF-6OF8 CCF 6 BISTABLES IN 3 OF 4 CHANNELS 2.7E-006 RPS-CCP-TM-CHA CH-A IN T&M 5.0E-003 RPS-CCX-CF-6OF8 CCF 6 ANALOG PROCESS LOGIC MODULES IN 3 OF 4 1.8E-006 RPS-ROD-CF-RCCAS CCF 10 OR MORE RCCAS FAIL TO DROP 1.2E-006 RPS-UVL-CF-UVDAB CCF UV DRIVERS TRAINS A AND B (2 0F 2) 1.0E-005 RPS-XHE-XE-NSGNL OPERATOR FAILS TO RESPOND WITH NO RPS SIGNAL 5.0E-001 RPS-XHE-XE-SIGNL OPERATOR FAILS TO RESPOND WITH RPS SIGNAL PRE 1.0E-002 RSS-MDP-TM-P1A RSS MDP P1A UNAVAILABLE DUE TO TEST AND MAINT 5.0E-003 RSS-MDP-TM-P1B RSS MDP P1B UNAVAILABLE DUE TO TEST AND MAINT 5.0E-003 RSS-MOV-CF-LPSI LPSI ISOLATION VALVES FAIL FROM COMMON CAUSE 2.7E-005 2006/05/31 13:15:02 page 11
LER 423-2005-002 29 Event Name Description Curr Prob RSS-XHE-XM-P1C OPERATOR FAILS TO ALIGN RSS P1C FOR RECIRCULA 1.0E+000 RSS-XHE-XM-P1D OPERATOR FAILS TO ALIGN RSS P1D FOR RECIRCULA 1.0E+000 SSC-XHE-XM-CDOWN OPERATOR FAILS TO INITIATE RCS COOLDOWN USING 1.0E-003 SSC1 RCS COOLDOWN (POST-LOCA) 3.0E-001 SWS-FAN-CF-HVY2ABR CCF OF SWS VENTILLATION FANS TO RUN 8.2E-006 SWS-FAN-CF-HVY2ABS CCF OF SWS VENTILLATION FANS TO START 1.0E-004 SWS-FAN-FS-2A SWS FAN HVY-2A FAILS TO START 2.5E-003 SWS-FAN-FS-2B SWS FAN HVY-2B FAILS TO START 2.5E-003 SWS-MOV-CF-50AB CCW ISOLATION VLVS FAIL FROM COMMON CAUSE TO 1.0E-005 SWS-MOV-CF-71AB TBCCW ISOLATION VLVS FAIL FROM COMMON CAUSE T 1.0E-005 SWS-MOV-OO-50A COMPONENT COOLING WATER ISOLATION VLV FAILS T 1.0E-003 SWS-MOV-OO-50B COMPONENT COOLING WATER ISOLATION VLV FAILS T 1.0E-003 SWS-MOV-OO-71A TBCCW ISOLATION VALVE FAILS TO CLOSE 1.0E-003 SWS-MOV-OO-71B TBCCW ISOLATION VALVE FAILS TO CLOSE 1.0E-003 SWS-PND-CF-23AB CCF O SWS VENTILLATION AODS TO OPEN 8.3E-006 2006/05/31 13:15:02 page 12