ML063170280
| ML063170280 | |
| Person / Time | |
|---|---|
| Site: | Kewaunee  |
| Issue date: | 07/11/2006 |
| From: | NRC/RES/DRASP/DDOERA/OEGI |
| To: | |
| Shared Package | |
| ML063170246 | List: |
| References | |
| IR-04-001 | |
| Download: ML063170280 (55) | |
Text
1 Final Precursor Analysis Accident Sequence Precursor Program ---Office of Nuclear Regulatory Research Kewaunee Power Station Auxiliary Feedwater Pumps Assumed to Fail from Postulated Loss of Primary Water Source Auxiliary Feedwater Pumps Postulated to Fall due to Air Ingestion Through Pump Packing Turbine-Driven Auxiliary Feedwater Pump Inoperable Due to Insufficient Net Positive Suction Head Emergency Diesel Generator Exhaust Ductwork Not Adequately Protected from Potential Tornado Winds &
Missiles EDG Unanalyzed Condition : Design Deficiency - CCW System Inoperable Due to Pump "RunOut" Conditions Unanalyzed internal flooding condition - inadequate design Event Date 2/11/2005 Event Date 3/26/2005 Event Date 4/20/2005 Event Date 3/24/2005 Event Date 3/28/2005 Event Date 3/15/2005 LER 305-2005-002-01 (AFW)
LER 305-2005-006-00 (AFW)
LER 305-2005-008-01 (AFW)
LER 305-2005-005-01 (EDG)
LER 305-2005-007-00 (CCW)
LER 305-2005-004-01 (Int. Flood)
Total windowed importance of 6 LERs Total without Internal Flood CDP = 1.4 x 10-5 CDP = 4 x 10-8 CDP < 9 x 10 -7 CDP = 3 x 10 -4 CDP = 3E-04 CDP = 1.4 x 10-5 July 11, 2006 Condition Summary Auxiliary feedwater pump (AFW) plant conditions that are reported in three different LERs in a three-month period are discussed and analyzed as a single plant condition in this document, since they lead to the potential failure of all three AFW pumps.
Two additional LERs, LER 305-2005-005-01 (EDG) and LER 305-2005-007-00 (CCW) are also discussed in Appendices A and B of this document. Finally, the internal flooding LER 305-2005-004-01 importance already calculated in a separate ASP analysis is also windowed with the five LERs analyzed in this report to calculate the total importance.
LER-305/2005-002 2
Condition
Description:
- 1)
Auxiliary Feedwater Pumps Assumed to Fail from Postulated Loss of Primary Water Source - Safe Shutdown and Accident Analysis Assumptions Not Assured - Inadequate Design of Pump Protective Equipment. Event Date 2/11/2005. LER 305-2005-002-01.
On 2/11/2005, while the Kewaunee Nuclear Power Plant (KNPP) was operating at full power, plant engineering personnel discovered that the AFW system discharge pressure switches may not operate in time to protect the AFW pumps from damage in the event of a loss of condensate storage tank (CST) water caused by a tornado. During a tornado that causes substantial plant equipment damage and a loss of offsite power, the AFW pumps are required equipment to conduct a safe plant shutdown. Compensatory measures were put in place to protect the pumps in case a tornado watch was declared for the area. These measures allowed continued plant operation. On 2/19/2005, while the plant was operating at full power, during investigative efforts for AFW system operability related to pump protection from a loss of CST water, the potential for a loss of the AFW pumps from a high energy line break (HELB) was discovered. The AFW pumps could be damaged during a feedwater system HELB due to damaged common suction piping. The damaged common piping is postulated to create the same effect on the AFW pumps as the loss of CST inventory. Consequently, the AFW pumps could not be assured to be operable under all postulated design basis HELB scenarios.
As a consequence of the 2/19/2005 discovery, a plant shutdown was completed on 2/20/2005.
In both events the scenario that causes the pump failures is also a scenario that requires the AFW pumps to support a required plant shutdown. Also, in both cases, it can be assumed that all available AFW pumps could be affected by the failure.
All three AFW pumps are expected to start on a plant trip as a consequence of low steam generator [SG] level signals that are created. A reactor trip is an expected consequence of the scenarios that are identified as the contributors to the events described Considering the scenarios, main feed HELB and a tornado induced loss of off site power, the need for the AFW pumps is inherently more important. In effect, the consequential loss of AFW under the scenarios described introduces a loss of secondary cooling event.
The significance of a tornado event is reduced by the low probability of occurrence of an initiating tornado of the magnitude assumed. Also, there is a chance that the tornado that could be expected to strike the KNPP site and plant proper will be of substantially lower magnitude such that total CST damage would not occur.
The probability of a HELB occurring that would cause damage to all three AFW pumps is also a low probability event. Although HELBs are required to be assumed to occur, in this instance the HELB would have to occur in the worst case orientation to incur the worst case damage to the common suction piping.
LER-305/2005-002 3
2)
Auxiliary Feedwater Pumps Postulated to Fall due to Air Ingestion Through Pump Packing, Event Date 3/26/2005, LER 305-2005-006-00 On March 26, 2005, while the Kewaunee Nuclear Power Plant was in the refueling shutdown mode, plant personnel determined a potential existed for damage to the AFW pumps due to air ingestion through the pump's packing gland. A conservative calculation has shown that during certain main steam line break (MSLB) post-accident conditions the pressure in the pump's inlet chamber can be sub-atmospheric for short periods. During those short sub-atmospheric periods cooling and lubrication of the pump's packing would stop, air could flow through the packing and into the inlet chamber, causing damage to the pump due to air entrainment.
Communication with the pump's vendor indicates the pump can handle up to 5% gas by volume without distress. At 20% gas by volume there is a good chance that the pump will lose prime and run gas bound.
Seizure of the rotor would then occur almost immediately."
The AFW pump shafts are sealed with mechanical packing and require a small amount of leak-off water to cool the packing and seal the pump. When the leak-off cooling water is lost, the packing can become damaged due to overheating. Damaged packing can cause an increase in the clearance between the packing and the shaft. If the inlet chamber conditions are sub-atmospheric, air could be drawn into the pump. In the case of KNPP's AFW pumps, air ingestion will potentially air bind then damage the pump.
During operation of the AFW pumps under certain accident conditions, the pressure at the pump suction could go below atmospheric pressure. Consequently, the KNPP system design is potentially vulnerable to the AFW pumps ingesting air. As stated above, the AFW pump can handle up to 5% gas by volume without distress and at 20% gas by volume there is a good chance that the pump will lose prime and run gas bound.
It is not currently known or easily calculated if the gap formed when the packing erodes will restrict air ingestion enough to keep the pump below 20% gas by volume during the period this condition is postulated to exist.
3)
Turbine-Driven Auxiliary Feedwater Pump Inoperable Due to Insufficient Net Positive Suction Head, Event Date 4/20/2005, LER 305-2005-008-01 During review of design information associated with a planned modification of the AFW system correct previously identified AFW system design deficiencies, it was determined that insufficient NPSH may exist for each of the plant's three AFW pumps following a MSLB event. The insufficient NPSH results, in part, from the excessive flow (runout) condition of the AFW pumps as they supply flow to the depressurized SG.
During a MSLB event, the resultant high flow rates cause a decrease in AFW pump NPSH.
When cavitation of the pump occurs, discharge pressure drops rapidly. The motor-driven AFW
LER-305/2005-002 4
pumps were equipped with a low discharge pressure switch that initiated a pump trip at 350 psig. From discussions with the pump vendor and from testing performed, it was determined that, for both the train A and train B motor-driven AFW pumps, there is a high probability that the AFW pump discharge pressure switches would have caused a protective trip of the motor-driven pumps, prior to the pumps being rendered inoperable from damage due to low NPSH.
Following action to isolate the faulted SG, the motor-driven AFW pumps could then have been restarted, supplying flow to the intact SG for continued heat removal. After undergoing a protective trip from their discharge pressure switches, sufficient time is available to manually restart the motor-driven AFW pumps for continued heat removal, due to the inherent cooldown that occurs as the faulted SG blows down in a MSLB event.
From discussion with the vendor, it was determined that there is a low probability that one or both of the motor-driven AFW pumps would have been damaged before tripping, rendering them unable to subsequently provide flow to the SGs. For large MSLBs, discharge pressure would be expected to drop rapidly, initiating a pump trip. While severe damage to the pump is unlikely, the vendor estimated a 5% probability that damage might occur that would render the pump unable to be restarted and deliver sufficient flow. For smaller MSLBs, pump discharge pressure may have dropped to a value slightly above the low discharge pressure setpoint. In this case, the pump would have operated for a short time while cavitating before operators took action that reduced flow. For this case, the vendor estimated a 15 to 20% probability of pump damage rendering the pump inoperable.
The turbine-driven AFW pump low discharge pressure switch was set to initiate a pump trip at 100 psig. Due to this low setpoint, it was determined that the switch would likely not have caused a protective trip of the pump in time to prevent pump damage. Consequently, in responding to a postulated MSLB, the turbine-driven pump would have been rendered inoperable due to low NPSH.
The cause of the occurrence is an original system design error. Previous calculations and testing that were performed for AFW system response to a MSLB event were focused on ensuring that adequate AFW flow would be provided by the turbine-driven AFW pump without due consideration of all suction head parameter concerns.
Conditional duration: Since the condition existed for a long time, the maximum time of one year is used for the duration in a conditional assessment.
Recovery opportunity: Recovery is modeled whenever applicable; especially for the plant condition for AFW pumps.
LER-305/2005-002 5
Analysis Results Analysis results are summarized in Table A.
Table A. Summary of Condition Importances Leading to Windowed Sum LER Type of Event Delta CDP Total Importance for LER Windowed Total Importance LER 305-2005-002-01 (AFW)
LER 305-2005-006-00 (AFW)
LER 305-2005-008-01 (AFW)
SLB 1.60E-06 SBO 1.20E-05 Seismic 2.10E-07 Tornado 6.70E-07 Total AFW-related) 1.45E-05 LER 305-2005-005-01 (EDG)
Tornado + LOOP 4.00E-08 LER 305-2005-007-00 (CCW)
Any initiating event 9.00E-07 LER 305-2005-004-01 (Int. Flood)
Internal flooding 3.00E-04 Total windowed importance of 6 LERs 3.15E-04 I.
AFW LERs Four different initiating events that may lead to increased risk due to this plant condition are modeled as discussed below.
1.
Steam Line Break (SLB) Events This event is modeled by Using the SLB event tree of Figure 1, with the initiating event frequency of 3.3E-04/year. First the base case CDF is quantified. Then the GENERATE option of the SAPHIRE software is used to quantify the CDF of the CURRENT case when all three AFW pumps are assumed failed. Table 1 shows the SLB sequence CDF and the total SLB CDF for the base and the current cases. Table 2 shows the cutsets of the current case. Table 5 contains the basic events changed in the change sets to get the current case. The calculated CDFs are as follows:
CDF(base) =
8.62E-10 /year CDF(current) =
8.06E-06/year CDF (with AFW recovery) = the same as CDF(base)
LER-305/2005-002 6
It is assumed that 20% of the time, all three AFW pumps will be catastrophically failed by the condition and can not be recovered. In the remaining 80% of the time the pumps are recoverable. The CDF of the plant condition then can be written as follows:
CDF(plant condition) = 0.2
- CDF(current) + 0.8
CDF(plant condition) = 1.61E-06 /year.
Condition Importance: CDP = [CDF(plant condition) - CDF(base) ]
- 1 year.
CDP(SLB) = 1.61E-06.
2.
Station Blackout (SBO) Events This event is modeled by Using the LOOP event tree of Figure 2, with the initiating event frequency of 3.59E-02/year. First the base case CDF is quantified. Then the GENERATE option of the SAPHIRE software is used to quantify the CDF of the CURRENT case when all three AFW pumps are assumed failed. Table 3 shows the LOOP sequences 18-X-X (the SBO sequences) and their CDFs and the total SBO CDF for the base and the current cases. Table 4 shows the cutsets of the current case. Table 5 contains the basic events changed in the change sets to get the current case. The calculated CDFs are as follows:
CDF(base) =
4.20E-06 /year CDF(current) =
4.38E-05 /year CDF (with TDP recovery) = the same as CDF(base)
It is assumed that 20% of the time, the TDP will be catastrophically failed by the condition and can not be recovered. In the remaining 80% of the time the TDP is recoverable. The CDF of the plant condition then can be written as follows:
CDF(plant condition) = 0.2
- CDF(current) + 0.8
- CDF(with TDP recovery)
CDF(plant condition) = 1.21E-05 /year.
Condition Importance: CDP = [CDF(plant condition) - CDF(base) ]
- 1 year.
LER-305/2005-002 7
3.
Seismic Events The seismic model is discussed in Appendix C. Four cases are studied as shown in Table C-1.
Case IV is used. Assuming the base case for seismic is negligible, the condition importance is CDP(seismic) = 2.1E-07.
4.
Tornado Events The likelihood of having a tornado with wind speeds that would damage the CSTs is calculated to be IE-TOR = 6.7E-07/year By the licensee. The licensee CDF estimate is 4E-08/year.
This estimate is used to calculate the condition importance from tornado events as CDP(tornado) = 4 E-08.
The condition importance is calculated as the sum of the importances of these events.
CDP(total-AFW) = 1.4 E-05.
II.
LER 305-2005-005-01 (EDG)
The condition importance is calculated in Appendix A as CDP(EDG) = 4 E-08.
III.
LER 305-2005-007-00 (CCW)
The condition importance is calculated in Appendix B as CDP(CCW) = 9 E-07.
IV.
LER 305-2005-004-01 (Int. Flood)
LER-305/2005-002 8
The condition importance for this LER is calculated in a separate ASP analysis as CDP (CCW) = 3 E-04.
V.
Total Condition Importance of Windowed Events The total condition importance from all six LERs discussed in this package can be estimated as the sum of each condition importance, since they apply to different initiating events.
The total windowed delta CDP for six LERs is calculated as CDP(Six LERs) = 3 E-04.
Importance The parameter of interest in this evaluation is the measure of the incremental change between the conditional probability of core damage for the period in which the condition existed and the nominal core damage probability obtained with the equipment availability modeled in the base case SPAR model.
The risk significance of these conditions with a duration of 8760 hours0.101 days <br />2.433 hours <br />0.0145 weeks <br />0.00333 months <br /> was determined by subtracting the baseline core damage probability (point estimate) from the conditional core damage probability (point estimate), as summarized in the previous section.
Dominant Sequences Dominant sequences for the newly introduced SLB event tree are discussed below. The SBO sequences are given in Table 4.
The SLB sequences for plant condition CDP calculation are reported in Tables 1 and 1a, and are defined in Figure 1 by the SLB event tree.
Failure of AFW pumps directs the operators to feed and bleed action (since MFW is also assumed nonrecoverable, due to the nature of the events considered). Thus, the following two sequences become dominant, especially due to failure of operator actions:
Large steamline break event occurs; Reactor trips; SI signal is generated; AFW is actuated and fails; HP injection starts;
LER-305/2005-002 9
MFW recovery is not feasible; Operators fail to implement feed and bleed; Large steamline break event occurs; Reactor trips; SI signal is generated; AFW is actuated and fails; HP injection starts; MFW recovery is not feasible; Operators implement feed and bleed; RWST is depleted; Operator action of switchover to sump recirculation fails; The following two failure combinations (cutsets) represent the major contributors to the above sequences:
1 LARGE STEAM LINE BREAK OCCURS (IE-SLB) 3.30E-04 OPERATOR FAILS TO INITIATE FEED AND BLEED COOLING (HPI-XHE-XM-FB) 2.00E-02 Core damage occurs = 6.6E-06 2
IE-SLB LARGE STEAM LINE BREAK OCCURS IE-SLB) 3.30E-04 (Feed and bleed cooling is successful) ( ~1.0 )
OPERATOR FAILS TO INITIATE HPR (HPR-XHE-XM) 2.00E-03 Core damage occurs = 6.6E-07 Results Tables The sequences are shown in Tables 1 and 1a.
The sequence definitions are shown in Figure 1.
The top cutsets are shown in Table 2.
SBO results are in tables 4 and 5.
Modeling Assumptions
LER-305/2005-002 10 Assessment summary This event was modeled as a condition assessment for 8760 hours0.101 days <br />2.433 hours <br />0.0145 weeks <br />0.00333 months <br />. The AFW pumps are not protected from failure due to air ingestion during tornado or seismic events; as well as from failure during potential runout conditions (large steamline break).
An analysis (covering all three AFW-related pump LERs) is performed, assuming a large steamline or feedline break would fail all three AFW pumps; but only 20% of the time, the failure is nonrecoverable. Additional two LERs that can be windowed with the three AFW-related LERs are also analyzed in Appendices A and B.
Key Modeling Assumptions All three AFW pumps are assumed to be failed by any one of the issues involved; a non-recovery factor of 0.2 is used, as mentioned in both the licensee and previous NRC analyses on the same condition.
SLB initiating event tree already created for the ASP analysis of McGuire LER 2005-002 event is used for Kewaunee. This event tree addresses the event tree nodes required for success in a SLB event for a PWR. Kewaunee-specific system failure models (fault trees) are used in the SLB event tree.
SLB, SBO, seismic, and tornado events are considered, consistent with the licensee and other NRC analyses for the same condition. Since the SLB event tree is newly introduced into the SPAr model for this condition, it is discussed in more detail here.
The existing SBO model is used, as summarized elsewhere. Seismic event analysis is given in Appendix C. The tornado contribution is deemed to be negligible and licensee analysis results are adopted.
SLB Event:
Base Case:
The base is defined as a large SLB event. The frequency of such an event is estimated below.
Plant Condition Cases:
Plant condition is defined as the deficiency in AFW pump configuration that would lead to failure of all three AFW pumps if a large HELB event occurs.
LER-305/2005-002 11 Table 3 provides the change sets used in the SPAR model to run base and condition cases.
SPAR model used in the analysis Kewaunee SPAR model version 3.31, run by SAPHIRE 7.26 software. SLB event tree and three fault trees are imported from the McGuire SPAR model and are incorporated into the Kewaunee SPAR model..
Unique system and operational considerations A SLB event tree is imported from the McGuire SPAR model. The event tree picture is given by Figure 1. This event tree introduces one new initiating event (IE-SLB), and three new fault trees. Each new fault tree has a single basic event, as discussed in the next sections.
Modifications to event tree and fault tree models A new event tree named SLB is introduced.
Three new fault trees named ISGTR, MSI, and HPI-STH are introduced. These fault trees are shown in Figures 2, 3, and 4.
Initiating event probability changes For the SLB event tree, a frequency is assigned for a large SLB, as discussed below:
IE-SLB = 3.3E-04/year.
This frequency is calculated with zero large HELB events (those that will rapidly reduce the faulted SG pressure to atmospheric pressure, before the MSIVs are closed) observed in 1520 power operation years for the fleet of domestic PWRs (taken from Kewaunee internal flooding LER-2005-004-00 ASP analysis). Non-informative prior is used to calculate the frequency as:
IE-SLB = (0 +0.5) / 1520 = 3.3 E-04/year.
It may be argued that, since Kewaunee has less than the average number of steam loops in the domestic PWR plant pool, its frequency may be lower.
LER-305/2005-002 12 Also note that the frequency of any size SLB or feedline break is IE-SLB = 1.1E-02/yr (from NUREG/CR-5750; categories K1+K3)
Thus, the probability of large SLB, given any SLB is the ratio 3.3E-04/1.1E-2 = 0.03.
Basic event probability changes Three new basic events are introduced, one in each of the new fault trees. These basic events are shown in Figures 2, 3, and 4 and they are taken from the McGuire SLB model. These values are deemed to be generic for PWRs, thus applicable to Kewaunee.
A probability of 20% non-recovery is also used in calculation of the condition importance.
Sensitivity / Uncertainty Analyses The major contributor to plant condition uncertainty is the nonrecovery probability of 0.2 used for AFW pumps. If this probability is increased to 1.0 (no recovery, the event importance associated with the three AFW LERs will increase about a factor of five.
When all six LERs are windowed, the importance is dominated by the internal flooding condition which is quantified in a separate ASP analysis. The sum of condition importances from other five LERs do not affect the first significant figure of the total windowed importance.
Other Windowed Events Two other events that are windowed with this AFW pump plant condition are discussed in Appendices A and B.
Note that the internal flooding ASP analysis for LER 2005-004 can also be windowed with the five LERs mentioned in this ASP analysis. Since the CDP of the internal flooding condition is much higher than the ones analyzed in the current package, the conclusions and the insights obtained would not be changed: these five LERs and the internal flooding LER address different initiating events. Thus, their condition importances are additive, but would not pile up to increase the importance beyond linearly.
LER-305/2005-002 13 References 1.
Licensee Event Report 305/05-002, Revision 1, Auxiliary Feedwater Pumps Assumed to Fail from Postulated Loss of Primary Water Source - Safe Shutdown and Accident Analysis Assumptions Not Assured - Inadequate Design of Pump Protective Equipment at Kewaunee Power station, dated January 30, 2006 (ADAMS Accession No. ML060410107).
2.
Licensee Event Report 305/005-005, Revision 1, Emergency Diesel Generator Exhaust Ductwork Not Adequately Protected from Potential Tornado Winds & Missiles, dated September 29, 2005 (ADAMS Accession No. ML052790505).
3.
Licensee Event Report 305/05-006, Revision 0, Auxiliary Feedwater Pumps Postulated to Fall due to Air Ingestion Through Pump Packing at kewaunee Power station at kewaunee Power station, dated May 25, 2005 (ADAMS Accession No. ML051530312).
4.
Licensee Event Report 305/05-007, revision 0, Unanalyzed Condition : Design Deficiency
- Component Cooling Water System Inoperable Due to Pump "Run Out" Conditions at kewaunee Power station, dated May 27, 2005 (ADAMS Accession No. ML051540040).
5.
Licensee Event Report 305/05-008, Revision 1, Turbine-Driven Auxiliary Feedwater Pump Inoperable Due to Insufficient Net Positive Suction Head at Kewaunee Power station, dated November 9, 2005 (ADAMS Accession No. ML053210186).
6.
Licensee event Report 305/05-004, Revision 0, Safe Shutdown Potentially Challenged By Unanalyzed Internal Flooding Events and Inadequate Design at Kewanuee Power station, dated May 16, 2005 (ADAMS Accession No. ML051440302). (This event is analyzed in a separate ASP package).
7.
Licensee event Report 369/05-002, Revision 1,Main Steam Isolation Valve Inoperable Due To Internal Binding at at McGuire Nuclear Station, dated January 23. 2006 (ADAMS Accession No. ML060380514) 8 KEWAUNEE SPAR-EE Model: KEWA-EE-312, August 2005 Revision 1.
Incorporation of External Events into SPAR Models - A Demonstration with Kewaunee Model. Unpublished report/model, US NRC, RES / OERA.
LER-305/2005-002 14 Table 1. Dominant Sequences Event tree Sequence Plant Condition Freq Per Year Base Freq Per Year Sequence Importance Failure SLB 08 7.12E-06 8.09E-11 7.12E-06 feed and bleed SLB 07 9.32E-07 3.72E-12 9.32E-07 sump recirculation SLB 09-31 2.92E-09 0.00E+00 2.92E-09 induced SGTR SLB 09-30 5.49E-10 0.00E+00 5.49E-10 induced SGTR SLB 10-11 4.12E-10 0.00E+00 4.12E-10 ATWS TOTALS =
8.06E-06 8.46E-11 8.06E-06 Note: See SLB event tree in Figure 1 for sequence definitions.
List of all event tree sequences, in the order they appear in Figure 1 are shwon in Table 1a
LER-305/2005-002 15 Table 1a. Large SLB Sequence Results Event tree Sequence Curr Freq Per Year Base Freq Per Year Difference Curr Cnt Base Cnt End State SLB 04 0.00E+00 6.99E-11
-6.99E-11 1
3 CD SLB 05 0.00E+00 4.69E-10
-4.69E-10 1
26 CD SLB 07 9.32E-07 3.72E-12 9.32E-07 609 2
CD SLB 08 7.12E-06 8.09E-11 7.12E-06 69 12 CD SLB 09-04 0.00E+00 0.00E+00 0.00E+00 0
0 CD SLB 09-06 6.60E-12 6.60E-12 0.00E+00 2
2 CD SLB 09-10 0.00E+00 0.00E+00 0.00E+00 0
0 CD SLB 09-12 0.00E+00 0.00E+00 0.00E+00 0
0 CD SLB 09-14 0.00E+00 0.00E+00 0.00E+00 0
0 CD SLB 09-17 6.61E-11 6.61E-11 0.00E+00 10 10 CD SLB 09-19 1.39E-10 1.39E-10 0.00E+00 6
6 CD SLB 09-21 1.02E-11 1.02E-11 0.00E+00 3
3 CD SLB 09-22 0.00E+00 0.00E+00 0.00E+00 0
0 CD SLB 09-23 0.00E+00 0.00E+00 0.00E+00 0
0 CD SLB 09-25 0.00E+00 0.00E+00 0.00E+00 0
0 CD SLB 09-27 0.00E+00 0.00E+00 0.00E+00 0
0 CD SLB 09-28 0.00E+00 0.00E+00 0.00E+00 0
0 CD SLB 09-30 5.49E-10 0.00E+00 5.49E-10 42 0
CD SLB 09-31 2.92E-09 0.00E+00 2.92E-09 24 0
CD SLB 10-04 0.00E+00 0.00E+00 0.00E+00 1
0 CD SLB 10-06 0.00E+00 0.00E+00 0.00E+00 1
0 CD SLB 10-08 0.00E+00 0.00E+00 0.00E+00 1
0 CD SLB 10-09 0.00E+00 0.00E+00 0.00E+00 1
0 CD SLB 10-10 0.00E+00 7.99E-12
-7.99E-12 1
1 CD SLB 10-11 4.12E-10 0.00E+00 4.12E-10 4
0 CD SLB 10-12 5.59E-12 5.59E-12 0.00E+00 1
1 CD SLB 11 3.99E-12 3.99E-12 0.00E+00 1
1 CD TOTALS =
8.06E-06 8.62E-10 8.06E-06 778 67
LER-305/2005-002 16 HPR SUMP RECIRC HPI-STH STOP OR THROTTLE HPI HPI HIGH PRESSURE INJECTION FAB FEED AND BLEED MSI MAIN STEAM LINE ISOLATION AFW AUXILIARY FEEDW ATER AVAILABLE ISGTR INDUCED SGTR RPS REACTOR PROTECTION SYSTEM IE-SLB STEAM LINE BREAK ENDSTATE 1
OK 2
OK 3
OK 4
CD 5
CD 6
OK 7
CD 8
CD 9
T SGTR 10 T ATW S 11 CD SLB - Kewaunee PW R B Steamline Break 2006/02/17 Figure 1. Steam Line Break Event Tree
LER-305/2005-002 17 HPI-STH 1.000E-2 HPI-XHE-STH STOP OR THROTTLE HPI OPERATOR FAILS TO STOP OR THROTTLE HPI HPI-STH - STOP OR THROTTLE HPI 2006/06/05 Page 184 Figure 2. HPI-STH Fault Tree
LER-305/2005-002 18 ISGTR 1.000E-2 PCS-SGT-RP-SLBISGTR INDUCED STGR STEAM LINE BREAK INDUCES A STEAM GENERATOR TUBE RUPTURE ISGTR - INDUCED SGTR 2006/06/05 Page 185 Figure 3. ISGTR Fault Tree
LER-305/2005-002 19 MSI 1.000E-2 MSS-MSIV-FTC MAIN STEAM LINE ISOLATION FAILURE OF MSIV TO CLOSE MSI - MAIN STEAM LINE ISOLATION 2006/06/05 Page 183 Figure 4. MSI Fault Tree
LER-305/2005-002 20 Table 2. Top Cutsets for the Plant Condition Case
% Total CDF Basic Event Description Event Prob.
1 82.12 6.60E-06 IE-SLB STEAM LINE BREAK 3.30E-04 HPI-XHE-XM-FB OPERATOR FAILS TO INITIATE FEED AND BLEED COOLING 2.00E-02 2
90.33 6.60E-07 IE-SLB STEAM LINE BREAK 3.30E-04 HPR-XHE-XM OPERATOR FAILS TO INITIATE HPR 2.00E-03 3
93.2 2.31E-07 IE-SLB STEAM LINE BREAK 3.30E-04 PPR-SRV-CC-PR2B PORV 2B FAILS TO OPEN ON DEMAND 7.00E-04 4
96.07 2.31E-07 IE-SLB STEAM LINE BREAK 3.30E-04 PPR-SRV-CC-PR2A PORV 2A FAILS TO OPEN ON DEMAND 7.00E-04 5
96.35 2.23E-08 IE-SLB STEAM LINE BREAK 3.30E-04 HPI-MDP-CF-STRT HPI PUMP COMMON CAUSE FAILURES TO START 6.77E-05 6
96.63 2.23E-08 IE-SLB STEAM LINE BREAK 3.30E-04 RHR-MDP-CF-STRT RHR PUMP COMMON CAUSE FAILURES TO START 6.77E-05 7
96.84 1.65E-08 IE-SLB STEAM LINE BREAK 3.30E-04 HPR-SMP-PG-SMP FAILURE OF SUMP 5.00E-05 8
97.04 1.57E-08 IE-SLB STEAM LINE BREAK 3.30E-04 PPR-SRV-CF-PORVS CCF OF PORVs TO OPEN 4.76E-05 9
97.15 8.61E-09 IE-SLB STEAM LINE BREAK 3.30E-04 LPR-MOV-CF-350A1B CCF OF SUMP ISOLATION MOVs 350A AND 351B TO OPEN 2.61E-05 10 97.26 8.61E-09 IE-SLB STEAM LINE BREAK 3.30E-04 LPR-MOV-CF-350AB CCF OF SUMP ISOLATION MOVs 350A AND 350B TO OPEN 2.61E-05 11 97.37 8.61E-09 IE-SLB STEAM LINE BREAK 3.30E-04 LPR-MOV-CF-351AB CCF OF SUMP ISOLATION MOVs 351A AND 351B TO OPEN 2.61E-05 12 97.48 8.61E-09 IE-SLB STEAM LINE BREAK 3.30E-04 SWS-MOV-CF-1300AB CCF OF CCW HTXs SWS MOVs 1300 & B 2.61E-05 13 97.59 8.61E-09 IE-SLB STEAM LINE BREAK 3.30E-04 LPR-MOV-CF-351A0B CCF OF SUMP ISOLATION MOVs 351A AND 350B TO OPEN 2.61E-05 14 97.7 8.61E-09 IE-SLB STEAM LINE BREAK 3.30E-04 RHR-MOV-CF-299AB RHR ISOLATION RHR-299A&B TO SI TRAINS FAIL TO OPEN 2.61E-05 15 97.75 4.37E-09 IE-SLB STEAM LINE BREAK 3.30E-04 HPI-MDP-CF-RUN HPI PUMP COMMON CAUSE FAILURES TO run 1.32E-05 16 97.8 4.37E-09 IE-SLB STEAM LINE BREAK 3.30E-04 RHR-MDP-CF-RUN RHR PUMP COMMON CAUSE FAILURES TO RUN 1.32E-05
LER-305/2005-002
% Total CDF Basic Event Description Event Prob.
21 17 97.84 3.40E-09 IE-SLB STEAM LINE BREAK 3.30E-04 HPR-MOV-CF-208209 CCF OF RWST MINFLOW MOVs 1.03E-05 18 97.88 3.39E-09 IE-SLB STEAM LINE BREAK 3.30E-04 ABV-ACX-CF-STRT CCF OF AUX BLDG BSMT COOLING UNITS TO START 1.03E-05 19 97.92 3.35E-09 IE-SLB STEAM LINE BREAK 3.30E-04 CCW-HTX-CF-ALL COMMON CAUSE FAILURE OF CCW HEAT EXCHANGERS 1.01E-05 20 97.96 2.97E-09 IE-SLB STEAM LINE BREAK 3.30E-04 HPI-MDP-FS-1A HPI MDP 1A FAILS TO START 1.50E-03 RHR-MDP-TM-1B RHR MDP 1B UNAVAILABLE DUE TO TEST AND MAINTENANCE 6.00E-03 21 98 2.97E-09 IE-SLB STEAM LINE BREAK 3.30E-04 RHR-MDP-FS-1A RHR MDP 1A FAILS TO START 1.50E-03 RHR-MDP-TM-1B RHR MDP 1B UNAVAILABLE DUE TO TEST AND MAINTENANCE 6.00E-03 22 98.04 2.97E-09 IE-SLB STEAM LINE BREAK 3.30E-04 HPI-MDP-FS-1B HPI MDP 1B FAILS TO START 1.50E-03 RHR-MDP-TM-1A RHR MDP 1A UNAVAILABLE DUE TO TEST AND MAINTENANCE 6.00E-03 23 98.08 2.97E-09 IE-SLB STEAM LINE BREAK 3.30E-04 RHR-MDP-FS-1B RHR MDP 1B FAILS TO START 1.50E-03 RHR-MDP-TM-1A RHR MDP 1A UNAVAILABLE DUE TO TEST AND MAINTENANCE 6.00E-03 24 98.11 2.48E-09 IE-SLB STEAM LINE BREAK 3.30E-04 HPI-MDP-FS-1A HPI MDP 1A FAILS TO START 1.50E-03 HPI-MDP-TM-1B HPI MDP 1B UNAVAILABLE DUE TO TEST AND MAINTENANCE 5.00E-03 25 98.14 2.48E-09 IE-SLB STEAM LINE BREAK 3.30E-04 HPI-MDP-FS-1B HPI MDP 1B FAILS TO START 1.50E-03 HPI-MDP-TM-1A HPI MDP 1A UNAVAILABLE DUE TO TEST AND MAINTENANCE 5.00E-03 26 98.17 2.48E-09 IE-SLB STEAM LINE BREAK 3.30E-04 HPI-MDP-TM-1A HPI MDP 1A UNAVAILABLE DUE TO TEST AND MAINTENANCE 5.00E-03 RHR-MDP-FS-1B RHR MDP 1B FAILS TO START 1.50E-03 27 98.2 2.48E-09 IE-SLB STEAM LINE BREAK 3.30E-04 HPI-MDP-TM-1B HPI MDP 1B UNAVAILABLE DUE TO TEST AND MAINTENANCE 5.00E-03 RHR-MDP-FS-1A RHR MDP 1A FAILS TO START 1.50E-03 28 98.22 1.98E-09 IE-SLB STEAM LINE BREAK 3.30E-04 RHR-MDP-TM-1B RHR MDP 1B UNAVAILABLE DUE TO TEST AND MAINTENANCE 6.00E-03 RHR-MOV-CC-299A RHR ISOLATION RHR-299A TO SI TRAIN A FAILS TO OPEN 1.00E-03 29 98.24 1.98E-09 IE-SLB STEAM LINE BREAK 3.30E-04 RHR-MDP-TM-1B RHR MDP 1B UNAVAILABLE DUE TO TEST AND MAINTENANCE 6.00E-03
LER-305/2005-002
% Total CDF Basic Event Description Event Prob.
22 RHR-XHE-XR-HX1A OPERATOR FAILS TO RESTORE RHR HTX 1A FROM T&M 1.00E-03 30 98.26 1.98E-09 IE-SLB STEAM LINE BREAK 3.30E-04 RHR-MDP-TM-1A RHR MDP 1A UNAVAILABLE DUE TO TEST AND MAINTENANCE 6.00E-03 RHR-MOV-CC-299B RHR ISOLATION RHR-299B TO SI TRAIN B FAILS TO OPEN 1.00E-03 31 98.28 1.98E-09 IE-SLB STEAM LINE BREAK 3.30E-04 RHR-MDP-TM-1A RHR MDP 1A UNAVAILABLE DUE TO TEST AND MAINTENANCE 6.00E-03 RHR-XHE-XR-HX1B OPERATOR FAILS TO RESTORE RHR HTX 1B FROM T&M 1.00E-03 32 98.3 1.98E-09 IE-SLB STEAM LINE BREAK 3.30E-04 HPI-XHE-XR-1A OP FAILS TO RESTORE HPI MDP 1A AFTER T&M 1.00E-03 RHR-MDP-TM-1B RHR MDP 1B UNAVAILABLE DUE TO TEST AND MAINTENANCE 6.00E-03 33 98.32 1.98E-09 IE-SLB STEAM LINE BREAK 3.30E-04 HPI-XHE-XR-1B OP FAILS TO RESTORE HPI MDP 1B 1.00E-03 RHR-MDP-TM-1A RHR MDP 1A UNAVAILABLE DUE TO TEST AND MAINTENANCE 6.00E-03 34 98.34 1.98E-09 IE-SLB STEAM LINE BREAK 3.30E-04 RHR-MDP-TM-1B RHR MDP 1B UNAVAILABLE DUE TO TEST AND MAINTENANCE 6.00E-03 RHR-XHE-XR-1A OP FAILS TO RESTORE RHR MDP 1A 1.00E-03 35 98.36 1.98E-09 IE-SLB STEAM LINE BREAK 3.30E-04 RHR-MDP-TM-1A RHR MDP 1A UNAVAILABLE DUE TO TEST AND MAINTENANCE 6.00E-03 RHR-XHE-XR-1B OP FAILS TO RESTORE RHR MDP 1B 1.00E-03 36 98.38 1.98E-09 IE-SLB STEAM LINE BREAK 3.30E-04 RHR-MDP-TM-1B RHR MDP 1B UNAVAILABLE DUE TO TEST AND MAINTENANCE 6.00E-03 SWS-MOV-CC-1300A CCW HTX ISOLATION SWS MOV 1300A FAILS TO OPEN 1.00E-03 37 98.4 1.98E-09 IE-SLB STEAM LINE BREAK 3.30E-04 RHR-MDP-TM-1A RHR MDP 1A UNAVAILABLE DUE TO TEST AND MAINTENANCE 6.00E-03 SWS-MOV-CC-1300B CCW HTX B ISOLATION SWS MOV 1300B FAILS TO OPEN 1.00E-03 38 98.42 1.98E-09 IE-SLB STEAM LINE BREAK 3.30E-04 LPR-MOV-CC-SI350A SUMP ISOLATION MOV 350A TO LPR MDP 1A FAILS TO OPEN 1.00E-03 RHR-MDP-TM-1B RHR MDP 1B UNAVAILABLE DUE TO TEST AND MAINTENANCE 6.00E-03 39 98.44 1.98E-09 IE-SLB STEAM LINE BREAK 3.30E-04 LPR-MOV-CC-SI351A SUMP ISOLATION MOV 351A TO LPR MDP 1A FAILS TO OPEN 1.00E-03 RHR-MDP-TM-1B RHR MDP 1B UNAVAILABLE DUE TO TEST AND MAINTENANCE 6.00E-03
LER-305/2005-002
% Total CDF Basic Event Description Event Prob.
23 40 98.46 1.98E-09 IE-SLB STEAM LINE BREAK 3.30E-04 HPI-MOV-OO-SI5A RWST HPI ISOLATION MOV 5A FAILS TO CLOSE 1.00E-03 RHR-MDP-TM-1B RHR MDP 1B UNAVAILABLE DUE TO TEST AND MAINTENANCE 6.00E-03 41 98.48 1.98E-09 IE-SLB STEAM LINE BREAK 3.30E-04 LPR-MOV-OO-SI300A RWST ISOLATION MOV 300A FAILS TO CLOSE 1.00E-03 RHR-MDP-TM-1B RHR MDP 1B UNAVAILABLE DUE TO TEST AND MAINTENANCE 6.00E-03 42 98.5 1.98E-09 IE-SLB STEAM LINE BREAK 3.30E-04 LPR-MOV-OO-SI300B RWST ISOLATION MOV 300B FAILS TO CLOSE 1.00E-03 RHR-MDP-TM-1A RHR MDP 1A UNAVAILABLE DUE TO TEST AND MAINTENANCE 6.00E-03 43 98.52 1.98E-09 IE-SLB STEAM LINE BREAK 3.30E-04 LPR-MOV-CC-SI350B SUMP ISOLATION MOV 350B TO LPR MDP 1B FAILS TO OPEN 1.00E-03 RHR-MDP-TM-1A RHR MDP 1A UNAVAILABLE DUE TO TEST AND MAINTENANCE 6.00E-03 44 98.54 1.98E-09 IE-SLB STEAM LINE BREAK 3.30E-04 LPR-MOV-CC-SI351B SUMP ISOLATION MOV 351B TO LPR MDP 1B FAILS TO OPEN 1.00E-03 RHR-MDP-TM-1A RHR MDP 1A UNAVAILABLE DUE TO TEST AND MAINTENANCE 6.00E-03 45 98.56 1.98E-09 IE-SLB STEAM LINE BREAK 3.30E-04 HPI-MOV-OO-SI5B RWST HPI ISOLATION MOV 5B FAILS TO CLOSE 1.00E-03 RHR-MDP-TM-1A RHR MDP 1A UNAVAILABLE DUE TO TEST AND MAINTENANCE 6.00E-03 46 98.58 1.65E-09 IE-SLB STEAM LINE BREAK 3.30E-04 HPI-MDP-TM-1B HPI MDP 1B UNAVAILABLE DUE TO TEST AND MAINTENANCE 5.00E-03 RHR-MOV-CC-299A RHR ISOLATION RHR-299A TO SI TRAIN A FAILS TO OPEN 1.00E-03 47 98.6 1.65E-09 IE-SLB STEAM LINE BREAK 3.30E-04 HPI-MDP-TM-1B HPI MDP 1B UNAVAILABLE DUE TO TEST AND MAINTENANCE 5.00E-03 RHR-XHE-XR-HX1A OPERATOR FAILS TO RESTORE RHR HTX 1A FROM T&M 1.00E-03 48 98.62 1.65E-09 IE-SLB STEAM LINE BREAK 3.30E-04 HPI-MDP-TM-1A HPI MDP 1A UNAVAILABLE DUE TO TEST AND MAINTENANCE 5.00E-03 RHR-MOV-CC-299B RHR ISOLATION RHR-299B TO SI TRAIN B FAILS TO OPEN 1.00E-03 49 98.64 1.65E-09 IE-SLB STEAM LINE BREAK 3.30E-04 HPI-MDP-TM-1A HPI MDP 1A UNAVAILABLE DUE TO TEST AND MAINTENANCE 5.00E-03
LER-305/2005-002
% Total CDF Basic Event Description Event Prob.
24 RHR-XHE-XR-HX1B OPERATOR FAILS TO RESTORE RHR HTX 1B FROM T&M 1.00E-03 50 98.66 1.65E-09 IE-SLB STEAM LINE BREAK 3.30E-04 HPI-MDP-TM-1B HPI MDP 1B UNAVAILABLE DUE TO TEST AND MAINTENANCE 5.00E-03 LPR-MOV-OO-SI300A RWST ISOLATION MOV 300A FAILS TO CLOSE 1.00E-03 51 98.68 1.65E-09 IE-SLB STEAM LINE BREAK 3.30E-04 HPI-MDP-TM-1A HPI MDP 1A UNAVAILABLE DUE TO TEST AND MAINTENANCE 5.00E-03 HPI-XHE-XR-1B OP FAILS TO RESTORE HPI MDP 1B 1.00E-03 52 98.7 1.65E-09 IE-SLB STEAM LINE BREAK 3.30E-04 HPI-MDP-TM-1B HPI MDP 1B UNAVAILABLE DUE TO TEST AND MAINTENANCE 5.00E-03 LPR-MOV-CC-SI350A SUMP ISOLATION MOV 350A TO LPR MDP 1A FAILS TO OPEN 1.00E-03 53 98.72 1.65E-09 IE-SLB STEAM LINE BREAK 3.30E-04 HPI-MDP-TM-1B HPI MDP 1B UNAVAILABLE DUE TO TEST AND MAINTENANCE 5.00E-03 LPR-MOV-CC-SI351A SUMP ISOLATION MOV 351A TO LPR MDP 1A FAILS TO OPEN 1.00E-03 54 98.74 1.65E-09 IE-SLB STEAM LINE BREAK 3.30E-04 HPI-MDP-TM-1B HPI MDP 1B UNAVAILABLE DUE TO TEST AND MAINTENANCE 5.00E-03 HPI-XHE-XR-1A OP FAILS TO RESTORE HPI MDP 1A AFTER T&M 1.00E-03 55 98.76 1.65E-09 IE-SLB STEAM LINE BREAK 3.30E-04 HPI-MDP-TM-1B HPI MDP 1B UNAVAILABLE DUE TO TEST AND MAINTENANCE 5.00E-03 RHR-XHE-XR-1A OP FAILS TO RESTORE RHR MDP 1A 1.00E-03 56 98.78 1.65E-09 IE-SLB STEAM LINE BREAK 3.30E-04 HPI-MDP-TM-1A HPI MDP 1A UNAVAILABLE DUE TO TEST AND MAINTENANCE 5.00E-03 LPR-MOV-CC-SI350B SUMP ISOLATION MOV 350B TO LPR MDP 1B FAILS TO OPEN 1.00E-03 57 98.8 1.65E-09 IE-SLB STEAM LINE BREAK 3.30E-04 HPI-MDP-TM-1A HPI MDP 1A UNAVAILABLE DUE TO TEST AND MAINTENANCE 5.00E-03 LPR-MOV-CC-SI351B SUMP ISOLATION MOV 351B TO LPR MDP 1B FAILS TO OPEN 1.00E-03 58 98.82 1.65E-09 IE-SLB STEAM LINE BREAK 3.30E-04 HPI-MDP-TM-1A HPI MDP 1A UNAVAILABLE DUE TO TEST AND MAINTENANCE 5.00E-03 LPR-MOV-OO-SI300B RWST ISOLATION MOV 300B FAILS TO CLOSE 1.00E-03 59 98.84 1.65E-09 IE-SLB STEAM LINE BREAK 3.30E-04 HPI-MDP-TM-1B HPI MDP 1B UNAVAILABLE DUE TO TEST AND MAINTENANCE 5.00E-03
LER-305/2005-002
% Total CDF Basic Event Description Event Prob.
25 HPI-MOV-OO-SI5A RWST HPI ISOLATION MOV 5A FAILS TO CLOSE 1.00E-03 60 98.86 1.65E-09 IE-SLB STEAM LINE BREAK 3.30E-04 HPI-MDP-TM-1A HPI MDP 1A UNAVAILABLE DUE TO TEST AND MAINTENANCE 5.00E-03 HPI-MOV-OO-SI5B RWST HPI ISOLATION MOV 5B FAILS TO CLOSE 1.00E-03 61 98.88 1.65E-09 IE-SLB STEAM LINE BREAK 3.30E-04 HPI-MDP-TM-1A HPI MDP 1A UNAVAILABLE DUE TO TEST AND MAINTENANCE 5.00E-03 RHR-XHE-XR-1B OP FAILS TO RESTORE RHR MDP 1B 1.00E-03 62 98.9 1.65E-09 IE-SLB STEAM LINE BREAK 3.30E-04 HPI-MDP-TM-1B HPI MDP 1B UNAVAILABLE DUE TO TEST AND MAINTENANCE 5.00E-03 SWS-MOV-CC-1300A CCW HTX ISOLATION SWS MOV 1300A FAILS TO OPEN 1.00E-03 63 98.92 1.65E-09 IE-SLB STEAM LINE BREAK 3.30E-04 HPI-MDP-TM-1A HPI MDP 1A UNAVAILABLE DUE TO TEST AND MAINTENANCE 5.00E-03 SWS-MOV-CC-1300B CCW HTX B ISOLATION SWS MOV 1300B FAILS TO OPEN 1.00E-03 64 98.94 1.58E-09 IE-SLB STEAM LINE BREAK 3.30E-04 DCP-BDC-LP-BRA102 FAILURE OF 125VDC BUS BRA-102 4.80E-06 65 98.96 1.58E-09 IE-SLB STEAM LINE BREAK 3.30E-04 DCP-BDC-LP-BRB104 FAILURE OF 125VDC BUS BRB-104 4.80E-06 66 98.98 1.58E-09 IE-SLB STEAM LINE BREAK 3.30E-04 DCP-BDC-LP-BRA104 FAILURE OF 125VDC BUS BRA-104 4.80E-06 67 99 1.58E-09 IE-SLB STEAM LINE BREAK 3.30E-04 DCP-BDC-LP-BRB102 FAILURE OF 125VDC BUS BRB-102 4.80E-06 68 99.02 1.58E-09 IE-SLB STEAM LINE BREAK 3.30E-04 HPI-CKV-CF-SI12AB CCF OF HPI/HPR DISCHARGE CHECK VAVLES SI-12A & B INTO COLD LEGS 4.78E-06 69 99.04 1.58E-09 IE-SLB STEAM LINE BREAK 3.30E-04 HPI-CKV-CF-13AB CCF OF HPI/HPR DISCHARGE CHECK VAVLES SI-13A & B INTO COLD LEGS 4.78E-06 70 99.06 1.58E-09 IE-SLB STEAM LINE BREAK 3.30E-04 HPI-CKV-CF-SI6AB CCF OF HPI MDP DISCHARGE CHECK VALVES SI-6A & B 4.78E-06 71 99.08 1.58E-09 IE-SLB STEAM LINE BREAK 3.30E-04 RHR-CKV-CF-RHR5AB CCF OF RHR MDPs DISCHARGE CHECK RHR-5A & 5B VALVES 4.78E-06 72 99.1 1.32E-09 IE-SLB STEAM LINE BREAK 3.30E-04
LER-305/2005-002
% Total CDF Basic Event Description Event Prob.
26 HPI-XHE-XM-FB OPERATOR FAILS TO INITIATE FEED AND BLEED COOLING 2.00E-02 MFW-XHE-XL-SITRIP OPERATOR FAILS TO RECOVER MFW (SI SIGNAL) 4.00E-02 PCS-SGT-RP-SLBISGTR STEAM LINE BREAK INDUCES A STEAM GENERATOR TUBE RUPTURE 1.00E-02 SGA-FAULTED STEAM GENERATOR A FAULTED 5.00E-01 73 99.12 1.32E-09 IE-SLB STEAM LINE BREAK 3.30E-04 HPI-XHE-XM-FB OPERATOR FAILS TO INITIATE FEED AND BLEED COOLING 2.00E-02 MFW-XHE-XL-SITRIP OPERATOR FAILS TO RECOVER MFW (SI SIGNAL) 4.00E-02 PCS-SGT-RP-SLBISGTR STEAM LINE BREAK INDUCES A STEAM GENERATOR TUBE RUPTURE 1.00E-02 SGB-FAULTED STEAM GENERATOR B FAULTED 5.00E-01 74 99.14 1.24E-09 IE-SLB STEAM LINE BREAK 3.30E-04 HPI-MDP-FS-1B HPI MDP 1B FAILS TO START 1.50E-03 RHR-HTX-TM-1A RHR HEAT EXCHANGER 1A UNAVAILABLE DUE TO T&M 2.50E-03 75 99.16 1.24E-09 IE-SLB STEAM LINE BREAK 3.30E-04 HPI-MDP-FS-1A HPI MDP 1A FAILS TO START 1.50E-03 RHR-HTX-TM-1B RHR HEAT EXCHANGER 1B UNAVAILABLE DUE TO T&M 2.50E-03 76 99.18 1.24E-09 IE-SLB STEAM LINE BREAK 3.30E-04 RHR-HTX-TM-1A RHR HEAT EXCHANGER 1A UNAVAILABLE DUE TO T&M 2.50E-03 RHR-MDP-FS-1B RHR MDP 1B FAILS TO START 1.50E-03 77 99.2 1.24E-09 IE-SLB STEAM LINE BREAK 3.30E-04 RHR-HTX-TM-1B RHR HEAT EXCHANGER 1B UNAVAILABLE DUE TO T&M 2.50E-03 RHR-MDP-FS-1A RHR MDP 1A FAILS TO START 1.50E-03 78 99.21 1.02E-09 IE-SLB STEAM LINE BREAK 3.30E-04 HPI-MDP-FR-1A HPI MDP 1A FAILS TO RUN 5.15E-04 RHR-MDP-TM-1B RHR MDP 1B UNAVAILABLE DUE TO TEST AND MAINTENANCE 6.00E-03 79 99.22 1.02E-09 IE-SLB STEAM LINE BREAK 3.30E-04 RHR-MDP-FR-1A RHR MDP 1A FAILS TO RUN 5.15E-04 RHR-MDP-TM-1B RHR MDP 1B UNAVAILABLE DUE TO TEST AND MAINTENANCE 6.00E-03 80 99.23 1.02E-09 IE-SLB STEAM LINE BREAK 3.30E-04 HPI-MDP-FR-1B HPI MDP 1B FAILS TO RUN 5.15E-04 RHR-MDP-TM-1A RHR MDP 1A UNAVAILABLE DUE TO TEST AND MAINTENANCE 6.00E-03 81 99.24 1.02E-09 IE-SLB STEAM LINE BREAK 3.30E-04 RHR-MDP-FR-1B RHR MDP 1B FAILS TO RUN 5.15E-04 RHR-MDP-TM-1A RHR MDP 1A UNAVAILABLE DUE TO TEST AND MAINTENANCE 6.00E-03 82 99.25 1.02E-09 IE-SLB STEAM LINE BREAK 3.30E-04
LER-305/2005-002
% Total CDF Basic Event Description Event Prob.
27 CCW-MDP-CF-1ABRUN CCF OF CCW MDP'S TO RUN (2) 3.08E-06 83 99.26 8.50E-10 IE-SLB STEAM LINE BREAK 3.30E-04 HPI-MDP-FR-1A HPI MDP 1A FAILS TO RUN 5.15E-04 HPI-MDP-TM-1B HPI MDP 1B UNAVAILABLE DUE TO TEST AND MAINTENANCE 5.00E-03 Sum 99.26 7.98E-06
LER-305/2005-002 28 Table 3. Change Sets Used to Quantify the Plant Condition and Base Cases Change Set for Plant Condition : MSLB - NO AFW Event Calc.
Type Description Condition Assessment AFW-MDP-FR-1A T
AFW MDP 1A FAILS TO RUN AFW-MDP-FR-1B T
AFW MDP 1B FAILS TO RUN AFW-MDP-FS-1A T
AFW MDP 1A FAILS TO START AFW-MDP-FS-1B T
AFW MDP 1B FAILS TO START AFW-MDP-TM-1A T
AFW MDP 1A UNAVAILABLE DUE TO TEST AND MAINTENANCE AFW-MDP-TM-1B T
AFW MDP 1B UNAVAILABLE DUE TO TEST AND MAINTENANCE AFW-TDP-FR-1C T
AFW TDP 1C FAILS TO RUN AFW-TDP-FS-1C T
AFW TDP 1C FAILS TO START AFW-TDP-TM-1C T
AFW TDP 1C UNAVAILABLE DUE TO TEST AND MAINTENANCE IE-ISL-HPI F
ISLOCA IE 2-CKV HPI interface IE-ISL-LPI F
ISLOCA IE 2-CKV LPI interface IE-ISL-RHR F
ISLOCA IE 2-MOV RHR interface IE-LLOCA F
LARGE LOCA IE-LOAC5 F
LOSS OF AC BUS 5 IE-LOAC6 F
LOSS OF AC BUS 6 IE-LOCCW F
LOSS OF COMPONENT COOLING WATER IE-LODCA F
LOSS OF DC POWER BRA-104 IE-LODCB F
LOSS OF DC POWER BRB-104 IE-LOIA F
LOSS OF INSTRUMENT AIR IE-LOMFW F
Loss of Main Feedwater IE-LOOP F
LOSS OF OFFSITE POWER IE-LOSWS F
LOSS OF SERVICE WATER SYSTEM IE-MLOCA F
MEDIUM LOCA IE-RXVRUPT F
REACTOR VESSEL RUPTURE INITIATING EVENT IE-SGTR F
SGTR INITIATING EVENT IE-SLOCA F
SMALL LOCA IE-TRANS F
LER-305/2005-002 29 Change Set for the Base Case Event Calc.
Type Description IE-ISL-HPI F
ISLOCA IE 2-CKV HPI interface IE-ISL-LPI F
ISLOCA IE 2-CKV LPI interface IE-ISL-RHR F
ISLOCA IE 2-MOV RHR interface IE-LLOCA F
LARGE LOCA IE-LOAC5 F
LOSS OF AC BUS 5 IE-LOAC6 F
LOSS OF AC BUS 6 IE-LOCCW F
LOSS OF COMPONENT COOLING WATER IE-LODCA F
LOSS OF DC POWER BRA-104 IE-LODCB F
LOSS OF DC POWER BRB-104 IE-LOIA F
LOSS OF INSTRUMENT AIR IE-LOMFW F
Loss of Main Feedwater IE-LOOP F
LOSS OF OFFSITE POWER IE-LOSWS F
LOSS OF SERVICE WATER SYSTEM IE-MLOCA F
MEDIUM LOCA IE-RXVRUPT F
REACTOR VESSEL RUPTURE INITIATING EVENT IE-SGTR F
SGTR INITIATING EVENT IE-SLOCA F
SMALL LOCA IE-TRANS F
LER-305/2005-002 30 HPR HIGH PRESSURE RECIRC RHR RESIDUAL HEAT REMOVAL PZR RCS DEPRESS FOR LPI/RHR SSC SECONDARY SIDE COOLDOWN OPR-06H OFFSITE POW ER RECOVERY IN 6 HRS OPR-02H OFFSITE POWER RECOVERY IN 2 HRS FAB FEED AND BLEED HPI HIGH PRESSURE INJECTION LOSC RCP SEAL COOLING MAINTAINED PORV PORVs ARE CLOSED AFW AUXILIARY FEEDWATER EPS EMERGENCY POWER RPS REACTOR SHUTDOWN IE-LOOP OSS OF OFFSITE POW ER END-STATE FREQUENCY 1
OK 2
T LOOP-1 3
OK 4
OK 5
CD 6
OK 7
CD 8
OK 9
CD 10 OK 11 CD 12 CD 13 OK 14 CD 15 OK 16 CD 17 CD 18 T
SBO 19 T
ATWS HPR-L HPR-L FAB-L AFW-L PORV-L LOSC-L HPI-L LOOP - Kewaunee PWR B Loss of Offsite Power 2005/03/07 Figure 5.
LOOP Event Tree
LER-305/2005-002 31 Table 4. SBO Sequences Event tree Sequen ce Curr Freq Per Year Base Freq Per Year Difference Number of Cutsets (current case)
Number of Cutsets (base case)
LOOP 18-74 4.26E-05 1.03E-06 4.15E-05 537 2163 LOOP 18-72-3 1.11E-06 3.33E-08 1.08E-06 1548 1190 LOOP 18-72-2 1.31E-07 2.23E-09 1.28E-07 4749 319 LOOP 18-46 0.00E+00 4.94E-10
-4.94E-10 1
78 LOOP 18-52 0.00E+00 2.23E-10
-2.23E-10 1
45 LOOP 18-49 0.00E+00 1.20E-09
-1.20E-09 1
82 LOOP 18-47-3 0.00E+00 6.31E-12
-6.31E-12 1
1 LOOP 18-47-2 0.00E+00 7.74E-12
-7.74E-12 1
4 LOOP 18-44-3 0.00E+00 1.10E-12
-1.10E-12 1
1 LOOP 18-43 0.00E+00 2.46E-09
-2.46E-09 1
119 LOOP 18-41-3 0.00E+00 1.26E-11
-1.26E-11 1
1 LOOP 18-41-2 0.00E+00 2.02E-11
-2.02E-11 1
8 LOOP 18-40 0.00E+00 6.01E-11
-6.01E-11 1
17 LOOP 18-38-3 0.00E+00 1.45E-12
-1.45E-12 1
1 LOOP 18-36 0.00E+00 1.15E-10
-1.15E-10 1
28 LOOP 18-65 0.00E+00 3.32E-11
-3.32E-11 1
8 LOOP 18-71 0.00E+00 9.44E-08
-9.44E-08 1
402 LOOP 18-69-3 0.00E+00 8.73E-11
-8.73E-11 1
4 LOOP 18-69-2 0.00E+00 1.68E-10
-1.68E-10 1
40 LOOP 18-68 0.00E+00 1.06E-12
-1.06E-12 1
1 LOOP 18-62 0.00E+00 3.70E-12
-3.70E-12 1
2 LOOP 18-59 0.00E+00 4.06E-11
-4.06E-11 1
10 LOOP 18-04 0.00E+00 2.25E-07
-2.25E-07 1
967 LOOP 18-12-2 0.00E+00 6.94E-10
-6.94E-10 1
98 LOOP 18-08-8 0.00E+00 1.36E-12
-1.36E-12 1
1 LOOP 18-15-2 0.00E+00 4.22E-10
-4.22E-10 1
62 LOOP 18-14 0.00E+00 2.68E-09
-2.68E-09 1
218 LOOP 18-12-7 0.00E+00 1.04E-10
-1.04E-10 1
5 LOOP 18-17 0.00E+00 1.97E-08
-1.97E-08 1
180 LOOP 18-10 0.00E+00 2.14E-07
-2.14E-07 1
945 LOOP 18-08-7 0.00E+00 1.92E-09
-1.92E-09 1
12 LOOP 18-08-2 0.00E+00 1.46E-08
-1.46E-08 1
590 LOOP 18-07 0.00E+00 2.49E-06
-2.49E-06 1
360 LOOP 18-05-3 0.00E+00 1.50E-08
-1.50E-08 1
303 LOOP 18-15-3 0.00E+00 1.82E-10
-1.82E-10 1
4 LOOP 18-25-3 0.00E+00 1.61E-11
-1.61E-11 1
1 LOOP 18-25-2 0.00E+00 2.57E-11
-2.57E-11 1
8 LOOP 18-33 0.00E+00 4.93E-10
-4.93E-10 1
53 LOOP 18-31-3 0.00E+00 8.03E-12
-8.03E-12 1
1 LOOP 18-31-2 0.00E+00 9.86E-12
-9.86E-12 1
4 LOOP 18-30 0.00E+00 2.67E-10
-2.67E-10 1
52
LER-305/2005-002 32 LOOP 18-28-3 0.00E+00 1.26E-12
-1.26E-12 1
1 LOOP 18-27 0.00E+00 1.02E-09
-1.02E-09 1
77 LOOP 18-18-2 0.00E+00 9.73E-11
-9.73E-11 1
27 LOOP 18-05-2 0.00E+00 4.22E-08
-4.22E-08 1
2243 LOOP 18-24 0.00E+00 2.85E-11
-2.85E-11 1
10 LOOP 18-22-3 0.00E+00 1.50E-12
-1.50E-12 1
1 LOOP 18-20 0.00E+00 7.12E-09
-7.12E-09 1
314 LOOP 18-18-7 0.00E+00 1.78E-11
-1.78E-11 1
3 Sum =
4.38E-05 4.20E-06 3.96E-05 6880 11064
LER-305/2005-002 33 Table 5. SBO CDF Cutsets Cut No.
% Total CDF Basic Event Description Event Prob.
1 19.22 8.42E-06 IE-LOOP LOSS OF OFFSITE POWER 3.59E-02 EPS-DGN-CF-RUN COMMON CAUSE FAILURE OF DIESEL GENERATORS TO RUN 5.73E-04 EPS-XHE-XL-NR01H OPERATOR FAILS TO RECOVER EMERGENCY DIESEL IN 1 HOUR 7.72E-01 OEP-XHE-XL-NR01H OPERATOR FAILS TO RECOVER OFFSITE POWER IN 1 HOUR 5.30E-01 2
33.57 6.29E-06 IE-LOOP LOSS OF OFFSITE POWER 3.59E-02 EPS-DGN-FR-1A DIESEL GENERATOR 1A FAILS TO RUN 2.07E-02 EPS-DGN-FR-1B DIESEL GENERATOR 1B FAILS TO RUN 2.07E-02 EPS-XHE-XL-NR01H OPERATOR FAILS TO RECOVER EMERGENCY DIESEL IN 1 HOUR 7.72E-01 OEP-XHE-XL-NR01H OPERATOR FAILS TO RECOVER OFFSITE POWER IN 1 HOUR 5.30E-01 3
39.82 2.74E-06 IE-LOOP LOSS OF OFFSITE POWER 3.59E-02 EPS-DGN-FR-1B DIESEL GENERATOR 1B FAILS TO RUN 2.07E-02 EPS-DGN-TM-1A DIESEL GENERATOR 1A UNAVAILABLE DUE TO TEST AND MAINTENANCE 9.00E-03 EPS-XHE-XL-NR01H OPERATOR FAILS TO RECOVER EMERGENCY DIESEL IN 1 HOUR 7.72E-01 OEP-XHE-XL-NR01H OPERATOR FAILS TO RECOVER OFFSITE POWER IN 1 HOUR 5.30E-01 4
46.07 2.74E-06 IE-LOOP LOSS OF OFFSITE POWER 3.59E-02 EPS-DGN-FR-1A DIESEL GENERATOR 1A FAILS TO RUN 2.07E-02 EPS-DGN-TM-1B DIESEL GENERATOR 1B UNAVAILABLE DUE TO TEST AND MAINTENANCE 9.00E-03 EPS-XHE-XL-NR01H OPERATOR FAILS TO RECOVER EMERGENCY DIESEL IN 1 HOUR 7.72E-01 OEP-XHE-XL-NR01H OPERATOR FAILS TO RECOVER OFFSITE POWER IN 1 HOUR 5.30E-01 5
49.58 1.54E-06 IE-LOOP LOSS OF OFFSITE POWER 3.59E-02 EPS-DGN-CF-STRT COMMON CAUSE FAILURE OF DIESEL GENERATORS TO START 1.05E-04 EPS-XHE-XL-NR01H OPERATOR FAILS TO RECOVER EMERGENCY DIESEL IN 1 HOUR 7.72E-01 OEP-XHE-XL-NR01H OPERATOR FAILS TO RECOVER OFFSITE POWER IN 1 HOUR 5.30E-01 6
53.05 1.52E-06 IE-LOOP LOSS OF OFFSITE POWER 3.59E-02 EPS-FAN-CF-DGFS CCF OF DGN HVAC FANS TO START 1.04E-04 EPS-XHE-XL-NR01H OPERATOR FAILS TO RECOVER EMERGENCY DIESEL IN 1 HOUR 7.72E-01 OEP-XHE-XL-NR01H OPERATOR FAILS TO RECOVER OFFSITE POWER IN 1 HOUR 5.30E-01 7
56.52 1.52E-06 IE-LOOP LOSS OF OFFSITE POWER 3.59E-02
LER-305/2005-002 34 EPS-DGN-FR-1B DIESEL GENERATOR 1B FAILS TO RUN 2.07E-02 EPS-DGN-FS-1A DIESEL GENERATOR 1A FAILS TO START 5.00E-03 EPS-XHE-XL-NR01H OPERATOR FAILS TO RECOVER EMERGENCY DIESEL IN 1 HOUR 7.72E-01 OEP-XHE-XL-NR01H OPERATOR FAILS TO RECOVER OFFSITE POWER IN 1 HOUR 5.30E-01 8
59.99 1.52E-06 IE-LOOP LOSS OF OFFSITE POWER 3.59E-02 EPS-DGN-FR-1A DIESEL GENERATOR 1A FAILS TO RUN 2.07E-02 EPS-DGN-FS-1B DIESEL GENERATOR 1B FAILS TO START 5.00E-03 EPS-XHE-XL-NR01H OPERATOR FAILS TO RECOVER EMERGENCY DIESEL IN 1 HOUR 7.72E-01 OEP-XHE-XL-NR01H OPERATOR FAILS TO RECOVER OFFSITE POWER IN 1 HOUR 5.30E-01 9
61.72 7.60E-07 IE-LOOP LOSS OF OFFSITE POWER 3.59E-02 EPS-DGN-FR-1A DIESEL GENERATOR 1A FAILS TO RUN 2.07E-02 EPS-FAN-FS-DGB DIESEL GENERATOR B HVAC FAN ROOM B FAILS TO START 2.50E-03 EPS-XHE-XL-NR01H OPERATOR FAILS TO RECOVER EMERGENCY DIESEL IN 1 HOUR 7.72E-01 OEP-XHE-XL-NR01H OPERATOR FAILS TO RECOVER OFFSITE POWER IN 1 HOUR 5.30E-01 10 63.45 7.60E-07 IE-LOOP LOSS OF OFFSITE POWER 3.59E-02 EPS-DGN-FR-1B DIESEL GENERATOR 1B FAILS TO RUN 2.07E-02 EPS-FAN-FS-DGA DIESEL GENERATOR A HVAC FAN ROOM A FAILS TO START 2.50E-03 EPS-XHE-XL-NR01H OPERATOR FAILS TO RECOVER EMERGENCY DIESEL IN 1 HOUR 7.72E-01 OEP-XHE-XL-NR01H OPERATOR FAILS TO RECOVER OFFSITE POWER IN 1 HOUR 5.30E-01 11 64.96 6.61E-07 IE-LOOP LOSS OF OFFSITE POWER 3.59E-02 EPS-DGN-FS-1B DIESEL GENERATOR 1B FAILS TO START 5.00E-03 EPS-DGN-TM-1A DIESEL GENERATOR 1A UNAVAILABLE DUE TO TEST AND MAINTENANCE 9.00E-03 EPS-XHE-XL-NR01H OPERATOR FAILS TO RECOVER EMERGENCY DIESEL IN 1 HOUR 7.72E-01 OEP-XHE-XL-NR01H OPERATOR FAILS TO RECOVER OFFSITE POWER IN 1 HOUR 5.30E-01 12 66.47 6.61E-07 IE-LOOP LOSS OF OFFSITE POWER 3.59E-02 EPS-DGN-FS-1A DIESEL GENERATOR 1A FAILS TO START 5.00E-03 EPS-DGN-TM-1B DIESEL GENERATOR 1B UNAVAILABLE DUE TO TEST AND MAINTENANCE 9.00E-03 EPS-XHE-XL-NR01H OPERATOR FAILS TO RECOVER EMERGENCY DIESEL IN 1 HOUR 7.72E-01
LER-305/2005-002 35 OEP-XHE-XL-NR01H OPERATOR FAILS TO RECOVER OFFSITE POWER IN 1 HOUR 5.30E-01 13 67.86 6.08E-07 IE-LOOP LOSS OF OFFSITE POWER 3.59E-02 EPS-DGN-FR-1B DIESEL GENERATOR 1B FAILS TO RUN 2.07E-02 EPS-FAN-TM-DGA DGN 1A HVAC FAN ROOM A UNAVAILABLE DUE TO T&M 2.00E-03 EPS-XHE-XL-NR01H OPERATOR FAILS TO RECOVER EMERGENCY DIESEL IN 1 HOUR 7.72E-01 OEP-XHE-XL-NR01H OPERATOR FAILS TO RECOVER OFFSITE POWER IN 1 HOUR 5.30E-01 14 69.25 6.08E-07 IE-LOOP LOSS OF OFFSITE POWER 3.59E-02 EPS-DGN-FR-1A DIESEL GENERATOR 1A FAILS TO RUN 2.07E-02 EPS-FAN-TM-DGB DGN 1B HVAC FAN ROOM B UNAVAILABLE DUE TO T&M 2.00E-03 EPS-XHE-XL-NR01H OPERATOR FAILS TO RECOVER EMERGENCY DIESEL IN 1 HOUR 7.72E-01 OEP-XHE-XL-NR01H OPERATOR FAILS TO RECOVER OFFSITE POWER IN 1 HOUR 5.30E-01 15 70.29 4.56E-07 IE-LOOP LOSS OF OFFSITE POWER 3.59E-02 ACP-CRB-CC-601 CIRCUIT BREAKER I-503 TO BUS 1-6 FAILS TO OPEN 1.50E-03 EPS-DGN-FR-1A DIESEL GENERATOR 1A FAILS TO RUN 2.07E-02 EPS-XHE-XL-NR01H OPERATOR FAILS TO RECOVER EMERGENCY DIESEL IN 1 HOUR 7.72E-01 OEP-XHE-XL-NR01H OPERATOR FAILS TO RECOVER OFFSITE POWER IN 1 HOUR 5.30E-01 16 71.33 4.56E-07 IE-LOOP LOSS OF OFFSITE POWER 3.59E-02 ACP-CRB-CC-610 CIRCUIT BREAKER I-610 TO BUS 1-6 FAILS TO OPEN 1.50E-03 EPS-DGN-FR-1A DIESEL GENERATOR 1A FAILS TO RUN 2.07E-02 EPS-XHE-XL-NR01H OPERATOR FAILS TO RECOVER EMERGENCY DIESEL IN 1 HOUR 7.72E-01 OEP-XHE-XL-NR01H OPERATOR FAILS TO RECOVER OFFSITE POWER IN 1 HOUR 5.30E-01 17 72.37 4.56E-07 IE-LOOP LOSS OF OFFSITE POWER 3.59E-02 ACP-CRB-CC-503 CIRCUIT BREAKER I-503 TO BUS 1-5 FAILS TO OPEN 1.50E-03 EPS-DGN-FR-1B DIESEL GENERATOR 1B FAILS TO RUN 2.07E-02 EPS-XHE-XL-NR01H OPERATOR FAILS TO RECOVER EMERGENCY DIESEL IN 1 HOUR 7.72E-01 OEP-XHE-XL-NR01H OPERATOR FAILS TO RECOVER OFFSITE POWER IN 1 HOUR 5.30E-01 18 73.41 4.56E-07 IE-LOOP LOSS OF OFFSITE POWER 3.59E-02 ACP-CRB-CC-511 CIRCUIT BREAKER I-511 TO BUS 1-5 FAILS TO OPEN 1.50E-03 EPS-DGN-FR-1B DIESEL GENERATOR 1B FAILS TO RUN 2.07E-02 EPS-XHE-XL-NR01H OPERATOR FAILS TO RECOVER EMERGENCY DIESEL IN 1 HOUR 7.72E-01
LER-305/2005-002 36 OEP-XHE-XL-NR01H OPERATOR FAILS TO RECOVER OFFSITE POWER IN 1 HOUR 5.30E-01 19 74.45 4.56E-07 IE-LOOP LOSS OF OFFSITE POWER 3.59E-02 ACP-CRB-CC-501 CIRCUIT BREAKER I-501 TO BUS 1-5 FAILS TO OPEN 1.50E-03 EPS-DGN-FR-1B DIESEL GENERATOR 1B FAILS TO RUN 2.07E-02 EPS-XHE-XL-NR01H OPERATOR FAILS TO RECOVER EMERGENCY DIESEL IN 1 HOUR 7.72E-01 OEP-XHE-XL-NR01H OPERATOR FAILS TO RECOVER OFFSITE POWER IN 1 HOUR 5.30E-01 20 75.37 4.03E-07 IE-LOOP LOSS OF OFFSITE POWER 3.59E-02 EPS-AOV-CF-301AB CCF OF SWS MOVS 301A&B TO DGN 1A TO OPEN 2.75E-05 EPS-XHE-XL-NR01H OPERATOR FAILS TO RECOVER EMERGENCY DIESEL IN 1 HOUR 7.72E-01 OEP-XHE-XL-NR01H OPERATOR FAILS TO RECOVER OFFSITE POWER IN 1 HOUR 5.30E-01 21 76.21 3.67E-07 IE-LOOP LOSS OF OFFSITE POWER 3.59E-02 EPS-DGN-FS-1A DIESEL GENERATOR 1A FAILS TO START 5.00E-03 EPS-DGN-FS-1B DIESEL GENERATOR 1B FAILS TO START 5.00E-03 EPS-XHE-XL-NR01H OPERATOR FAILS TO RECOVER EMERGENCY DIESEL IN 1 HOUR 7.72E-01 OEP-XHE-XL-NR01H OPERATOR FAILS TO RECOVER OFFSITE POWER IN 1 HOUR 5.30E-01 22 76.96 3.31E-07 IE-LOOP LOSS OF OFFSITE POWER 3.59E-02 EPS-DGN-TM-1A DIESEL GENERATOR 1A UNAVAILABLE DUE TO TEST AND MAINTENANCE 9.00E-03 EPS-FAN-FS-DGB DIESEL GENERATOR B HVAC FAN ROOM B FAILS TO START 2.50E-03 EPS-XHE-XL-NR01H OPERATOR FAILS TO RECOVER EMERGENCY DIESEL IN 1 HOUR 7.72E-01 OEP-XHE-XL-NR01H OPERATOR FAILS TO RECOVER OFFSITE POWER IN 1 HOUR 5.30E-01 23 77.71 3.31E-07 IE-LOOP LOSS OF OFFSITE POWER 3.59E-02 EPS-DGN-TM-1B DIESEL GENERATOR 1B UNAVAILABLE DUE TO TEST AND MAINTENANCE 9.00E-03 EPS-FAN-FS-DGA DIESEL GENERATOR A HVAC FAN ROOM A FAILS TO START 2.50E-03 EPS-XHE-XL-NR01H OPERATOR FAILS TO RECOVER EMERGENCY DIESEL IN 1 HOUR 7.72E-01 OEP-XHE-XL-NR01H OPERATOR FAILS TO RECOVER OFFSITE POWER IN 1 HOUR 5.30E-01 24 78.4 3.04E-07 IE-LOOP LOSS OF OFFSITE POWER 3.59E-02 EPS-DGN-FR-1B DIESEL GENERATOR 1B FAILS TO RUN 2.07E-02 EPS-XHE-XL-NR01H OPERATOR FAILS TO RECOVER EMERGENCY DIESEL IN 1 HOUR 7.72E-01
LER-305/2005-002 37 EPS-XHE-XR-DGAF OPERATOR FAILS TO RESTORE DGN 1A FAN ROOM A AFTER T&M 1.00E-03 OEP-XHE-XL-NR01H OPERATOR FAILS TO RECOVER OFFSITE POWER IN 1 HOUR 5.30E-01 25 79.09 3.04E-07 IE-LOOP LOSS OF OFFSITE POWER 3.59E-02 EPS-DGN-FR-1B DIESEL GENERATOR 1B FAILS TO RUN 2.07E-02 EPS-XHE-XL-NR01H OPERATOR FAILS TO RECOVER EMERGENCY DIESEL IN 1 HOUR 7.72E-01 EPS-XHE-XR-1A OP FAILS TO RESTORE DIESEL GENERATOR 1A 1.00E-03 OEP-XHE-XL-NR01H OPERATOR FAILS TO RECOVER OFFSITE POWER IN 1 HOUR 5.30E-01 26 79.78 3.04E-07 IE-LOOP LOSS OF OFFSITE POWER 3.59E-02 EPS-DGN-FR-1A DIESEL GENERATOR 1A FAILS TO RUN 2.07E-02 EPS-XHE-XL-NR01H OPERATOR FAILS TO RECOVER EMERGENCY DIESEL IN 1 HOUR 7.72E-01 EPS-XHE-XR-DGBF OPERATOR FAILS TO RESTORE DGN 1B FAN ROOM B AFTER T&M 1.00E-03 OEP-XHE-XL-NR01H OPERATOR FAILS TO RECOVER OFFSITE POWER IN 1 HOUR 5.30E-01 27 80.47 3.04E-07 IE-LOOP LOSS OF OFFSITE POWER 3.59E-02 EPS-DGN-FR-1A DIESEL GENERATOR 1A FAILS TO RUN 2.07E-02 EPS-XHE-XL-NR01H OPERATOR FAILS TO RECOVER EMERGENCY DIESEL IN 1 HOUR 7.72E-01 EPS-XHE-XR-1B OP FAILS TO RESTORE DIESEL GENERATOR 1B 1.00E-03 OEP-XHE-XL-NR01H OPERATOR FAILS TO RECOVER OFFSITE POWER IN 1 HOUR 5.30E-01 28 81.09 2.74E-07 IE-LOOP LOSS OF OFFSITE POWER 3.59E-02 EPS-AOV-CC-301B SWS ISOLATION MOV 301B TO DGN 1B FAILS TO OPEN 9.00E-04 EPS-DGN-FR-1A DIESEL GENERATOR 1A FAILS TO RUN 2.07E-02 EPS-XHE-XL-NR01H OPERATOR FAILS TO RECOVER EMERGENCY DIESEL IN 1 HOUR 7.72E-01 OEP-XHE-XL-NR01H OPERATOR FAILS TO RECOVER OFFSITE POWER IN 1 HOUR 5.30E-01 29 81.71 2.74E-07 IE-LOOP LOSS OF OFFSITE POWER 3.59E-02 EPS-AOV-CC-301A SWS ISOLATION MOV 301A TO DGN 1A FAILS TO OPEN 9.00E-04 EPS-DGN-FR-1B DIESEL GENERATOR 1B FAILS TO RUN 2.07E-02 EPS-XHE-XL-NR01H OPERATOR FAILS TO RECOVER EMERGENCY DIESEL IN 1 HOUR 7.72E-01 OEP-XHE-XL-NR01H OPERATOR FAILS TO RECOVER OFFSITE POWER IN 1 HOUR 5.30E-01 30 82.31 2.65E-07 IE-LOOP LOSS OF OFFSITE POWER 3.59E-02 EPS-DGN-TM-1B DIESEL GENERATOR 1B UNAVAILABLE DUE TO TEST AND MAINTENANCE 9.00E-03
LER-305/2005-002 38 EPS-FAN-TM-DGA DGN 1A HVAC FAN ROOM A UNAVAILABLE DUE TO T&M 2.00E-03 EPS-XHE-XL-NR01H OPERATOR FAILS TO RECOVER EMERGENCY DIESEL IN 1 HOUR 7.72E-01 OEP-XHE-XL-NR01H OPERATOR FAILS TO RECOVER OFFSITE POWER IN 1 HOUR 5.30E-01 31 82.91 2.65E-07 IE-LOOP LOSS OF OFFSITE POWER 3.59E-02 EPS-DGN-TM-1A DIESEL GENERATOR 1A UNAVAILABLE DUE TO TEST AND MAINTENANCE 9.00E-03 EPS-FAN-TM-DGB DGN 1B HVAC FAN ROOM B UNAVAILABLE DUE TO T&M 2.00E-03 EPS-XHE-XL-NR01H OPERATOR FAILS TO RECOVER EMERGENCY DIESEL IN 1 HOUR 7.72E-01 OEP-XHE-XL-NR01H OPERATOR FAILS TO RECOVER OFFSITE POWER IN 1 HOUR 5.30E-01 32 83.36 1.98E-07 IE-LOOP LOSS OF OFFSITE POWER 3.59E-02 ACP-CRB-CC-601 CIRCUIT BREAKER I-503 TO BUS 1-6 FAILS TO OPEN 1.50E-03 EPS-DGN-TM-1A DIESEL GENERATOR 1A UNAVAILABLE DUE TO TEST AND MAINTENANCE 9.00E-03 EPS-XHE-XL-NR01H OPERATOR FAILS TO RECOVER EMERGENCY DIESEL IN 1 HOUR 7.72E-01 OEP-XHE-XL-NR01H OPERATOR FAILS TO RECOVER OFFSITE POWER IN 1 HOUR 5.30E-01 33 83.81 1.98E-07 IE-LOOP LOSS OF OFFSITE POWER 3.59E-02 ACP-CRB-CC-610 CIRCUIT BREAKER I-610 TO BUS 1-6 FAILS TO OPEN 1.50E-03 EPS-DGN-TM-1A DIESEL GENERATOR 1A UNAVAILABLE DUE TO TEST AND MAINTENANCE 9.00E-03 EPS-XHE-XL-NR01H OPERATOR FAILS TO RECOVER EMERGENCY DIESEL IN 1 HOUR 7.72E-01 OEP-XHE-XL-NR01H OPERATOR FAILS TO RECOVER OFFSITE POWER IN 1 HOUR 5.30E-01 34 84.26 1.98E-07 IE-LOOP LOSS OF OFFSITE POWER 3.59E-02 ACP-CRB-CC-503 CIRCUIT BREAKER I-503 TO BUS 1-5 FAILS TO OPEN 1.50E-03 EPS-DGN-TM-1B DIESEL GENERATOR 1B UNAVAILABLE DUE TO TEST AND MAINTENANCE 9.00E-03 EPS-XHE-XL-NR01H OPERATOR FAILS TO RECOVER EMERGENCY DIESEL IN 1 HOUR 7.72E-01 OEP-XHE-XL-NR01H OPERATOR FAILS TO RECOVER OFFSITE POWER IN 1 HOUR 5.30E-01 35 84.71 1.98E-07 IE-LOOP LOSS OF OFFSITE POWER 3.59E-02 ACP-CRB-CC-511 CIRCUIT BREAKER I-511 TO BUS 1-5 FAILS TO OPEN 1.50E-03 EPS-DGN-TM-1B DIESEL GENERATOR 1B UNAVAILABLE DUE TO TEST AND MAINTENANCE 9.00E-03
LER-305/2005-002 39 EPS-XHE-XL-NR01H OPERATOR FAILS TO RECOVER EMERGENCY DIESEL IN 1 HOUR 7.72E-01 OEP-XHE-XL-NR01H OPERATOR FAILS TO RECOVER OFFSITE POWER IN 1 HOUR 5.30E-01 36 85.16 1.98E-07 IE-LOOP LOSS OF OFFSITE POWER 3.59E-02 ACP-CRB-CC-501 CIRCUIT BREAKER I-501 TO BUS 1-5 FAILS TO OPEN 1.50E-03 EPS-DGN-TM-1B DIESEL GENERATOR 1B UNAVAILABLE DUE TO TEST AND MAINTENANCE 9.00E-03 EPS-XHE-XL-NR01H OPERATOR FAILS TO RECOVER EMERGENCY DIESEL IN 1 HOUR 7.72E-01 OEP-XHE-XL-NR01H OPERATOR FAILS TO RECOVER OFFSITE POWER IN 1 HOUR 5.30E-01 37 85.6 1.93E-07 IE-LOOP LOSS OF OFFSITE POWER 3.59E-02 EPS-DGN-CF-RUN COMMON CAUSE FAILURE OF DIESEL GENERATORS TO RUN 5.73E-04 HPI-XHE-XM-FB OPERATOR FAILS TO INITIATE FEED AND BLEED COOLING 2.00E-02
/OEP-XHE-XL-NR01H OPERATOR FAILS TO RECOVER OFFSITE POWER IN 1 HOUR 4.70E-01 38 86.02 1.84E-07 IE-LOOP LOSS OF OFFSITE POWER 3.59E-02 EPS-DGN-FS-1A DIESEL GENERATOR 1A FAILS TO START 5.00E-03 EPS-FAN-FS-DGB DIESEL GENERATOR B HVAC FAN ROOM B FAILS TO START 2.50E-03 EPS-XHE-XL-NR01H OPERATOR FAILS TO RECOVER EMERGENCY DIESEL IN 1 HOUR 7.72E-01 OEP-XHE-XL-NR01H OPERATOR FAILS TO RECOVER OFFSITE POWER IN 1 HOUR 5.30E-01 39 86.44 1.84E-07 IE-LOOP LOSS OF OFFSITE POWER 3.59E-02 EPS-DGN-FS-1B DIESEL GENERATOR 1B FAILS TO START 5.00E-03 EPS-FAN-FS-DGA DIESEL GENERATOR A HVAC FAN ROOM A FAILS TO START 2.50E-03 EPS-XHE-XL-NR01H OPERATOR FAILS TO RECOVER EMERGENCY DIESEL IN 1 HOUR 7.72E-01 OEP-XHE-XL-NR01H OPERATOR FAILS TO RECOVER OFFSITE POWER IN 1 HOUR 5.30E-01 40 86.78 1.47E-07 IE-LOOP LOSS OF OFFSITE POWER 3.59E-02 EPS-DGN-FS-1B DIESEL GENERATOR 1B FAILS TO START 5.00E-03 EPS-FAN-TM-DGA DGN 1A HVAC FAN ROOM A UNAVAILABLE DUE TO T&M 2.00E-03 EPS-XHE-XL-NR01H OPERATOR FAILS TO RECOVER EMERGENCY DIESEL IN 1 HOUR 7.72E-01 OEP-XHE-XL-NR01H OPERATOR FAILS TO RECOVER OFFSITE POWER IN 1 HOUR 5.30E-01 41 87.12 1.47E-07 IE-LOOP LOSS OF OFFSITE POWER 3.59E-02
LER-305/2005-002 40 EPS-DGN-FS-1A DIESEL GENERATOR 1A FAILS TO START 5.00E-03 EPS-FAN-TM-DGB DGN 1B HVAC FAN ROOM B UNAVAILABLE DUE TO T&M 2.00E-03 EPS-XHE-XL-NR01H OPERATOR FAILS TO RECOVER EMERGENCY DIESEL IN 1 HOUR 7.72E-01 OEP-XHE-XL-NR01H OPERATOR FAILS TO RECOVER OFFSITE POWER IN 1 HOUR 5.30E-01 42 87.45 1.44E-07 IE-LOOP LOSS OF OFFSITE POWER 3.59E-02 EPS-DGN-FR-1A DIESEL GENERATOR 1A FAILS TO RUN 2.07E-02 EPS-DGN-FR-1B DIESEL GENERATOR 1B FAILS TO RUN 2.07E-02 HPI-XHE-XM-FB OPERATOR FAILS TO INITIATE FEED AND BLEED COOLING 2.00E-02
/OEP-XHE-XL-NR01H OPERATOR FAILS TO RECOVER OFFSITE POWER IN 1 HOUR 4.70E-01 43 87.75 1.32E-07 IE-LOOP LOSS OF OFFSITE POWER 3.59E-02 EPS-DGN-TM-1B DIESEL GENERATOR 1B UNAVAILABLE DUE TO TEST AND MAINTENANCE 9.00E-03 EPS-XHE-XL-NR01H OPERATOR FAILS TO RECOVER EMERGENCY DIESEL IN 1 HOUR 7.72E-01 EPS-XHE-XR-DGAF OPERATOR FAILS TO RESTORE DGN 1A FAN ROOM A AFTER T&M 1.00E-03 OEP-XHE-XL-NR01H OPERATOR FAILS TO RECOVER OFFSITE POWER IN 1 HOUR 5.30E-01 44 88.05 1.32E-07 IE-LOOP LOSS OF OFFSITE POWER 3.59E-02 EPS-DGN-TM-1B DIESEL GENERATOR 1B UNAVAILABLE DUE TO TEST AND MAINTENANCE 9.00E-03 EPS-XHE-XL-NR01H OPERATOR FAILS TO RECOVER EMERGENCY DIESEL IN 1 HOUR 7.72E-01 EPS-XHE-XR-1A OP FAILS TO RESTORE DIESEL GENERATOR 1A 1.00E-03 OEP-XHE-XL-NR01H OPERATOR FAILS TO RECOVER OFFSITE POWER IN 1 HOUR 5.30E-01 45 88.35 1.32E-07 IE-LOOP LOSS OF OFFSITE POWER 3.59E-02 EPS-DGN-TM-1A DIESEL GENERATOR 1A UNAVAILABLE DUE TO TEST AND MAINTENANCE 9.00E-03 EPS-XHE-XL-NR01H OPERATOR FAILS TO RECOVER EMERGENCY DIESEL IN 1 HOUR 7.72E-01 EPS-XHE-XR-DGBF OPERATOR FAILS TO RESTORE DGN 1B FAN ROOM B AFTER T&M 1.00E-03 OEP-XHE-XL-NR01H OPERATOR FAILS TO RECOVER OFFSITE POWER IN 1 HOUR 5.30E-01 46 88.65 1.32E-07 IE-LOOP LOSS OF OFFSITE POWER 3.59E-02 EPS-DGN-TM-1A DIESEL GENERATOR 1A UNAVAILABLE DUE TO TEST AND MAINTENANCE 9.00E-03 EPS-XHE-XL-NR01H OPERATOR FAILS TO RECOVER EMERGENCY DIESEL IN 1 HOUR 7.72E-01
LER-305/2005-002 41 EPS-XHE-XR-1B OP FAILS TO RESTORE DIESEL GENERATOR 1B 1.00E-03 OEP-XHE-XL-NR01H OPERATOR FAILS TO RECOVER OFFSITE POWER IN 1 HOUR 5.30E-01 47 88.93 1.21E-07 IE-LOOP LOSS OF OFFSITE POWER 3.59E-02 EPS-FAN-CF-DGFR CCF OF DGN HVAC FANS TO RUN 8.23E-06 EPS-XHE-XL-NR01H OPERATOR FAILS TO RECOVER EMERGENCY DIESEL IN 1 HOUR 7.72E-01 OEP-XHE-XL-NR01H OPERATOR FAILS TO RECOVER OFFSITE POWER IN 1 HOUR 5.30E-01 48 89.2 1.19E-07 IE-LOOP LOSS OF OFFSITE POWER 3.59E-02 EPS-AOV-CC-301B SWS ISOLATION MOV 301B TO DGN 1B FAILS TO OPEN 9.00E-04 EPS-DGN-TM-1A DIESEL GENERATOR 1A UNAVAILABLE DUE TO TEST AND MAINTENANCE 9.00E-03 EPS-XHE-XL-NR01H OPERATOR FAILS TO RECOVER EMERGENCY DIESEL IN 1 HOUR 7.72E-01 OEP-XHE-XL-NR01H OPERATOR FAILS TO RECOVER OFFSITE POWER IN 1 HOUR 5.30E-01 49 89.47 1.19E-07 IE-LOOP LOSS OF OFFSITE POWER 3.59E-02 EPS-AOV-CC-301A SWS ISOLATION MOV 301A TO DGN 1A FAILS TO OPEN 9.00E-04 EPS-DGN-TM-1B DIESEL GENERATOR 1B UNAVAILABLE DUE TO TEST AND MAINTENANCE 9.00E-03 EPS-XHE-XL-NR01H OPERATOR FAILS TO RECOVER EMERGENCY DIESEL IN 1 HOUR 7.72E-01 OEP-XHE-XL-NR01H OPERATOR FAILS TO RECOVER OFFSITE POWER IN 1 HOUR 5.30E-01 50 89.72 1.10E-07 IE-LOOP LOSS OF OFFSITE POWER 3.59E-02 ACP-CRB-CC-601 CIRCUIT BREAKER I-503 TO BUS 1-6 FAILS TO OPEN 1.50E-03 EPS-DGN-FS-1A DIESEL GENERATOR 1A FAILS TO START 5.00E-03 EPS-XHE-XL-NR01H OPERATOR FAILS TO RECOVER EMERGENCY DIESEL IN 1 HOUR 7.72E-01 OEP-XHE-XL-NR01H OPERATOR FAILS TO RECOVER OFFSITE POWER IN 1 HOUR 5.30E-01 51 89.97 1.10E-07 IE-LOOP LOSS OF OFFSITE POWER 3.59E-02 ACP-CRB-CC-610 CIRCUIT BREAKER I-610 TO BUS 1-6 FAILS TO OPEN 1.50E-03 EPS-DGN-FS-1A DIESEL GENERATOR 1A FAILS TO START 5.00E-03 EPS-XHE-XL-NR01H OPERATOR FAILS TO RECOVER EMERGENCY DIESEL IN 1 HOUR 7.72E-01 OEP-XHE-XL-NR01H OPERATOR FAILS TO RECOVER OFFSITE POWER IN 1 HOUR 5.30E-01 52 90.22 1.10E-07 IE-LOOP LOSS OF OFFSITE POWER 3.59E-02
LER-305/2005-002 42 ACP-CRB-CC-503 CIRCUIT BREAKER I-503 TO BUS 1-5 FAILS TO OPEN 1.50E-03 EPS-DGN-FS-1B DIESEL GENERATOR 1B FAILS TO START 5.00E-03 EPS-XHE-XL-NR01H OPERATOR FAILS TO RECOVER EMERGENCY DIESEL IN 1 HOUR 7.72E-01 OEP-XHE-XL-NR01H OPERATOR FAILS TO RECOVER OFFSITE POWER IN 1 HOUR 5.30E-01 53 90.47 1.10E-07 IE-LOOP LOSS OF OFFSITE POWER 3.59E-02 ACP-CRB-CC-511 CIRCUIT BREAKER I-511 TO BUS 1-5 FAILS TO OPEN 1.50E-03 EPS-DGN-FS-1B DIESEL GENERATOR 1B FAILS TO START 5.00E-03 EPS-XHE-XL-NR01H OPERATOR FAILS TO RECOVER EMERGENCY DIESEL IN 1 HOUR 7.72E-01 OEP-XHE-XL-NR01H OPERATOR FAILS TO RECOVER OFFSITE POWER IN 1 HOUR 5.30E-01 54 90.72 1.10E-07 IE-LOOP LOSS OF OFFSITE POWER 3.59E-02 ACP-CRB-CC-501 CIRCUIT BREAKER I-501 TO BUS 1-5 FAILS TO OPEN 1.50E-03 EPS-DGN-FS-1B DIESEL GENERATOR 1B FAILS TO START 5.00E-03 EPS-XHE-XL-NR01H OPERATOR FAILS TO RECOVER EMERGENCY DIESEL IN 1 HOUR 7.72E-01 OEP-XHE-XL-NR01H OPERATOR FAILS TO RECOVER OFFSITE POWER IN 1 HOUR 5.30E-01 55 90.93 9.19E-08 IE-LOOP LOSS OF OFFSITE POWER 3.59E-02 EPS-FAN-FS-DGA DIESEL GENERATOR A HVAC FAN ROOM A FAILS TO START 2.50E-03 EPS-FAN-FS-DGB DIESEL GENERATOR B HVAC FAN ROOM B FAILS TO START 2.50E-03 EPS-XHE-XL-NR01H OPERATOR FAILS TO RECOVER EMERGENCY DIESEL IN 1 HOUR 7.72E-01 OEP-XHE-XL-NR01H OPERATOR FAILS TO RECOVER OFFSITE POWER IN 1 HOUR 5.30E-01
LER-305/2005-002 43 Table 6. Change Set for SBO Current Case Event Calc. Type Description Change/Flag Set : LOOP-NO-AFW LOOP without AFW AFW-MDP-FR-1A T
AFW MDP 1A FAILS TO RUN AFW-MDP-FR-1B T
AFW MDP 1B FAILS TO RUN AFW-MDP-FS-1A T
AFW MDP 1A FAILS TO START AFW-MDP-FS-1B T
AFW MDP 1B FAILS TO START AFW-MDP-TM-1A T
AFW MDP 1A UNAVAILABLE DUE TO TEST AND MAINTENANCE AFW-MDP-TM-1B T
AFW MDP 1B UNAVAILABLE DUE TO TEST AND MAINTENANCE AFW-TDP-FR-1C T
AFW TDP 1C FAILS TO RUN AFW-TDP-FS-1C T
AFW TDP 1C FAILS TO START AFW-TDP-TM-1C T
AFW TDP 1C UNAVAILABLE DUE TO TEST AND MAINTENANCE IE-ISL-HPI F
ISLOCA IE 2-CKV HPI interface IE-ISL-LPI F
ISLOCA IE 2-CKV LPI interface IE-ISL-RHR F
ISLOCA IE 2-MOV RHR interface IE-LLOCA F
LARGE LOCA IE-LOAC5 F
LOSS OF AC BUS 5 IE-LOAC6 F
LOSS OF AC BUS 6 IE-LOCCW F
LOSS OF COMPONENT COOLING WATER IE-LODCA F
LOSS OF DC POWER BRA-104 IE-LODCB F
LOSS OF DC POWER BRB-104 IE-LOIA F
LOSS OF INSTRUMENT AIR IE-LOMFW F
Loss of Main Feedwater IE-LOSWS F
LOSS OF SERVICE WATER SYSTEM IE-MLOCA F
MEDIUM LOCA IE-RXVRUPT F
REACTOR VESSEL RUPTURE INITIATING EVENT IE-SGTR F
SGTR INITIATING EVENT IE-SLB F
STEAM LINE BREAK IE-SLOCA F
SMALL LOCA IE-TRANS F
LER-305/2005-002 44 Appendix A. Windowed Condition LER 305-2005-005-01 LER 305-2005-005-01 Emergency Diesel Generator Exhaust Ductwork Not Adequately Protected from Potential Tornado Winds & Missiles EDG Condition
Description:
On March 24, 2005, with unit in the refueling shutdown condition, a walk-down was being conducted in the Kewaunee Power Station (KPS) Turbine Building, as part of an evaluation of the Turbine Building response to design basis tornado winds. Sections of sheet metal panel siding on the Turbine Building are designed to blow out / blow in due to tornado wind loading, as given in Updated Safety Analysis Report (USAR) Appendix B.
However, loss of this siding would expose the Class 3 portion of the A and B Emergency Diesel Generator (EDG) exhaust ductwork to tornado wind loads. The response of the sheet metal panels would be that the ductwork could be subjected to full design basis tornado force. Exposure to tornado winds would likely result in deformation of the ductwork for each EDG. On April 19, 2005, during the evaluation to determine a resolution to the tornado wind EDG ductwork deformation problem, it was determined that the EDG exhaust ductwork was also susceptible to turbine and tornado missiles. Appendix B of the USAR evaluates turbine and tornado missiles for Class 1 portion of the EDG. It does not address how the Class 3 structures and components associated with the EDG could impact its operation if impacted by a missile. Deformation of the EDG exhaust ducts could result in some reduction of EDG capacity, due to postulated increase in exhaust backpressure. The apparent cause relative to this condition is the original design of the plant, which did not take these effects into account. Design Change Request DCR-3582 was completed and it reinforced the guides for the EDG exhaust ducts and reinforced the existing structural steel to carry the guide loads. A probabilistic evaluation of tornado missiles, utilizing the TORMIS computer program, was performed. An evaluation of the effects of turbine missiles on the
'B' EDG exhaust duct was also performed.
Licensee performed a probabilistic evaluation of tornado missiles:
The TORMIS computer program develops the probability of tornado missiles striking the modeled plant structures and other targets, using probability techniques. The NRC, in a Safety Evaluation Report dated October 26, 1983, concluded that TORMIS is an acceptable approach for demonstrating compliance with 10 CFR 50 Appendix A General Design Criteria 2, regarding 50 Appendix A General Design Criteria 2, regarding protection of safety-related plant features from the effects of tornado and high wind generated missiles.
The results of the TORMIS evaluation show the damage probability per year for the EDG exhaust vents is 4.09E-07. This probability is less than 1 E-06 per year. Per NUREG 0800, NRC Standard Review Plan, Section 3.5.1.4 - Missiles Generated by Natural Phenomena, and its associated Regulatory Guides, if the probability of a damaging missile strike is less than 1 E-06 per year, then it can be considered not credible.
LER-305/2005-002 45 The results of evaluation showed the 'B' EDG exhaust duct has sufficient turbine missile protection based on the criteria of NUREG 0800, Section 3.5.1.3. KPS has demonstrated turbine disc integrity, the turbine overspeed protection has redundancy and has been evaluated to show that it minimizes the potential for missile generation due to an overspeed condition, and a redundant EDG is available.
Analysis:
This plant condition is modeled as a severe tornado event that would cause LOOP and also fail one EDG (EDG-B).
The initiating event frequency of the severe tornado event that will damage EDG-B is calculated by the licensee as 4.1E-07/yr. For the purposes of this analysis, it is assumed that this value is optimistic by a factor of ten. Thus, the following initiating event frequency is used; IE-TOR = 4.1E-06/yr.
Probability of EDG-B failure given IE-TOR = 1.0 Probability of LOOP given IE-TOR occurs = 1.0.
It is also postulated that the EDG-B can not be repaired, and the offsite power can not be recovered in 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
CCDP(given LOOP occurs and EDG-B fails) = 8.676E-03 (calculated from SPAR; using change set in Table A-1. )
Base line CDP for this event with EDG-B available is assumed to be negligible (conservative assumption).
CDP = Plant condition importance for a 8760-hour exposure time
= 4.1E-06
- 8.676E-03 = 4 E-08.
==
Conclusion:==
Since CDP is considerably less than the ASP acceptance criteria of 1.0E-06, this LER need not be kept in the ASP data base.
LER-305/2005-002 46 Table A-1. Change set used for CCDP calculation Change Set for 2005-005-01 Tornado with LOOP + loss of EDG B - CDP Event Calc.
Type or Proba bility Description Tornado with LOOP + loss of EDG B - CDP EPS-DGN-TM-1B T
DIESEL GENERATOR 1B UNAVAILABLE DUE TO TEST AND MAINTENANCE EPS-XHE-XR-1B T
OP FAILS TO RESTORE DIESEL GENERATOR 1B IE-ISL-HPI F
ISLOCA IE 2-CKV HPI interface IE-ISL-LPI F
ISLOCA IE 2-CKV LPI interface IE-ISL-RHR F
ISLOCA IE 2-MOV RHR interface IE-LLOCA F
LARGE LOCA IE-LOAC5 F
LOSS OF AC BUS 5 IE-LOAC6 F
LOSS OF AC BUS 6 IE-LOCCW F
LOSS OF COMPONENT COOLING WATER IE-LODCA F
LOSS OF DC POWER BRA-104 IE-LODCB F
LOSS OF DC POWER BRB-104 IE-LOIA F
LOSS OF INSTRUMENT AIR IE-LOMFW F
Loss of Main Feedwater IE-LOOP 1.0 LOSS OF OFFSITE POWER IE-LOSWS F
LOSS OF SERVICE WATER SYSTEM IE-MLOCA F
MEDIUM LOCA IE-RXVRUPT F
REACTOR VESSEL RUPTURE INITIATING EVENT IE-SGTR F
SGTR INITIATING EVENT IE-SLB F
STEAM LINE BREAK IE-SLOCA F
SMALL LOCA IE-TRANS F
TRANSIENT OEP-XHE-XL-NR01H T
OPERATOR FAILS TO RECOVER OFFSITE POWER IN 1 HOUR OEP-XHE-XL-NR02H T
OPERATOR FAILS TO RECOVER OFFSITE POWER IN 2 HOURS OEP-XHE-XL-NR03H T
OPERATOR FAILS TO RECOVER OFFSITE POWER IN 3 HOURS OEP-XHE-XL-NR04H T
OPERATOR FAILS TO RECOVER OFFSITE POWER IN 4 HOURS OEP-XHE-XL-NR05H T
OPERATOR FAILS TO RECOVER OFFSITE POWER IN 5 HOURS OEP-XHE-XL-NR06H T
OPERATOR FAILS TO RECOVER OFFSITE POWER IN 6 HOURS OEP-XHE-XL-NR07H T
OPERATOR FAILS TO RECOVER OFFSITE POWER IN 7 HOURS OEP-XHE-XL-NR08H T
OPERATOR FAILS TO RECOVER OFFSITE POWER IN 8 HOURS OEP-XHE-XL-NR09H T
OPERATOR FAILS TO RECOVER OFFSITE POWER IN 9 HOURS OEP-XHE-XL-NR10H T
OPERATOR FAILS TO RECOVER OFFSITE POWER IN 10 HOURS OEP-XHE-XL-NR10H2 T
OPERATOR FAILS TO RECOVER OFFSITE POWER IN 10 HOURS (GIVEN FAILURE AT 2)
OEP-XHE-XL-NR10H4 T
OPERATOR FAILS TO RECOVER OFFSITE POWER IN 10 HOURS (GIVEN FAILURE AT 4)
OEP-XHE-XL-NR11H T
OPERATOR FAILS TO RECOVER OFFSITE POWER IN 11 HOURS OEP-XHE-XL-NR12H T
OPERATOR FAILS TO RECOVER OFFSITE POWER IN 12 HOURS OEP-XHE-XL-NR13H T
OPERATOR FAILS TO RECOVER OFFSITE POWER IN 13 HOURS OEP-XHE-XL-NR14H T
OPERATOR FAILS TO RECOVER OFFSITE POWER IN 14 HOURS OEP-XHE-XL-NR150M T
OPERATOR FAILS TO RECOVER OFFSITE POWER IN 2.5 HOURS OEP-XHE-XL-NR15H T
OPERATOR FAILS TO RECOVER OFFSITE POWER IN 15 HOURS OEP-XHE-XL-NR16H T
OPERATOR FAILS TO RECOVER OFFSITE POWER IN 16 HOURS OEP-XHE-XL-NR17H T
OPERATOR FAILS TO RECOVER OFFSITE POWER IN 17 HOURS
LER-305/2005-002 Event Calc.
Type or Proba bility Description 47 OEP-XHE-XL-NR18H T
OPERATOR FAILS TO RECOVER OFFSITE POWER IN 18 HOURS OEP-XHE-XL-NR19H T
OPERATOR FAILS TO RECOVER OFFSITE POWER IN 19 HOURS OEP-XHE-XL-NR20H T
OPERATOR FAILS TO RECOVER OFFSITE POWER IN 20 HOURS OEP-XHE-XL-NR21H T
OPERATOR FAILS TO RECOVER OFFSITE POWER IN 21 HOURS OEP-XHE-XL-NR22H T
OPERATOR FAILS TO RECOVER OFFSITE POWER IN 22 HOURS OEP-XHE-XL-NR23H T
OPERATOR FAILS TO RECOVER OFFSITE POWER IN 23 HOURS OEP-XHE-XL-NR24H T
OPERATOR FAILS TO RECOVER OFFSITE POWER IN 24 HOURS OEP-XHE-XL-NR30M T
OPERATOR FAILS TO RECOVER OFFSITE POWER IN 30 MINUTES OEP-XHE-XL-NR90M T
OPERATOR FAILS TO RECOVER OFFSITE POWER IN 90 MINUTES
LER-305/2005-002 48 Appendix B. Windowed Condition LER 305-2005-007-00 LER 305-2005-007-00 Unanalyzed Condition : Design Deficiency - CCW System Inoperable Due to Pump "RunOut" Conditions Condition
Description:
On March 28, 2005 with the plant in Refueling Shutdown Mode, a past operability concern was identified with the plant's Component Cooling Water (CCW) System. Specifically, on January 23, 2002, plant personnel identified a potential "run out" concern with the CCW pumps. The condition assumed CCW being aligned to both Residual Heat Removal (RHR) heat exchangers and both CCW pumps running. If a loss of power caused the loss of one CCW train and the associated train's isolation valve to the RHR heat exchanger could not be closed, there would be a potential concern with pump "run out" and pump damage for the CCW pump that continued to run.
The pump "run-out" concern was determined to be an original plant design issue and was initially resolved by isolating the non-safeguards loads on the CCW system and installing a valve position limiter on a non-critical CCW system flow control valve.
Isolation of the non-safeguards loads on the CCW system and the installation of the valve position limiter on a non-critical CCW system flow control valve were completed approximately 49.75 hours8.680556e-4 days <br />0.0208 hours <br />1.240079e-4 weeks <br />2.85375e-5 months <br /> from the time the potential concern was identified. The valve position limiter that was installed was proven effective upon the completion of special operating procedures which verified by testing that a single CCW pump would not experience "run-out" flow conditions when all CCW safeguards loads, including both trains of RHR heat exchangers were supplied by a single CCW pump.
Analysis:
This plant condition is modeled as follows for an 8760 hour0.101 days <br />2.433 hours <br />0.0145 weeks <br />0.00333 months <br /> exposure time:
Any random event occurs during a year; Both CCW trains are assumed operational at the same time (conservative assumption);
One CCW train fails to run ( 2* 2.413E-03; used CCW-1-TR-SS fault tree))
Operator fails to close isolation valve for the failed CCW train (HEP = 0.1; screening value).
Second running CCW pump fails due to runout (probability = 1) plant CDF from any one of the random initiating events when both CCW pumps fail ( 1.873E-03; calculated by SPAR using a change set).
The failure of a CCW train is modeled by using the fault tree named CCW-1-TR-FAILS-SS (see Figure B-1). This fault tree is made by copying and trimming the existing CCW-A fault tree. The fault tree quantification gives 2.413E-03 and each running train can fail by the same probability;
LER-305/2005-002 49 thus a factor of 2 is used.
The closure of the isolation valve for the failed CCW train is assumed to be an operator action. A screening value of 0.1 is used for the operator to diagnose that one of the two running CCW pumps failed and that the operator closes the isolation valve before the second running pump fails.
CDF(given both CCW pumps fail during any random event during a year) = 1.873E-03 (calculated from SPAR; using change set in Table B-1; 43811 cutsets).
Base line CDP for this event with second CCW pump not subject to runout failure mode is assumed to be negligible (conservative assumption).
CDP = Plant condition importance for a 8760-hour exposure time
= CDP of plant condition CDP = ( 2
- 2.413E-03 ) *( 0.1 ) * (1.873E-03) = 9 E-07.
==
Conclusion:==
The bounding CCDP is below but very close to the ASP acceptance threshold of 1E-06. However, there are conservatisms in the analysis, such as both CCW pumps running in all events, the screening HEP value, and ignoring the base CDP. Thus, a best estimate plant condition may be expected to be lower than the calculated bounding value. Since the CDP is less than the ASP acceptance criteria of 1.0E-06, this LER need not be kept in the ASP data base.
Interaction with other windowed events: The other windowed events, such as the ones related to AFW pumps and the one for internal flooding are dominated by failure of operator actions, with some residual contribution from component failures. Thus, superimposing this CCW condition on the other plant conditions would make very small impact on the overall importance, other than an additive manner.
Normally, both CCW trains are not expected to run during normal power operation. Thus, this condition is not deemed to be a significant contributor to the initiating event frequency of total loss of CCW system.
LER-305/2005-002 50 CCW-1-TR-FAILS-SS CCW-A1 CCW -A1-RUN 3.084E-6 CCW -MDP-CF-1ABRUN 1.200E-4 CCW -MDP-FR-1A 9
ACP-BUS51 CCW -A1-START 1.00 0E-4 CCW-CKV-CC-3A 1.7 60E-6 CCW-CKV-CF-3AB 9.020E-5 CCW -M DP-CF-1ABS 2.000E-3 CCW-M DP-FS-1A 44 DCP-BRA104 CCW -A2 1.014E-5 CCW-HTX-CF-ALL 6.000E-5 CCW-HTX-PG-1A 1.440E-6 CCW -MOV-OC-6A 1 71 SW S-HDRA CCW HEAT EXCHANGER 1A FAILS FAILURES OF CCW MDP 1A NO FLOW TO AUX BLDG FROM SW S HDR A 125 VDC VITAL BUS BRA-104 FAILS CO MPONENT COOLING WATER TRAIN A FAIL S CCW MDP 1A FAILS T O START FAILURES OF CCW MDP 1A 480 VAC SAFETY BUS I-51 FAILS COMMON CAUSE FAILURE OF CCW HEAT EXCHANGERS CCF O F CCW MDP DISCHARGE CKVs TO OPEN CCF OF CCW MDP's TO ST AR T CCF OF CCW MDP'S T O RUN (2)
CCW HEAT EXCHANGER 1A FAILS CCW MDP 1A DISCHARGE CHECK VALVE CC-3 A FAILS TO OPEN CCW MDP 1A FAILS TO START CCW MDP 1 A FAILS TO RUN CCW HEAT EXCHANG ER 1A O UTLET MOV 6A FAILS TO REMAIN O PEN CCW-1-TR-FAILS-SS - COMPONENT COOLING WATER TRAIN A FAILS 2006/06/05 Page 182 Figure B-1 Fault Tree CCW-1-TR-FAILS-SS
LER-305/2005-002 51 Table B-1 Change Set for Calculating CDF When CCW Fails Change Set used in 2005-007-00 Condition with both CCW pumps failed Event Calc.
Type Description CCW-MDP-CF-1ABRUN T
CCW-MDP-CF-1ABS T
CCF OF CCW MDP's TO START CCW-MDP-FR-1A T
CCW MDP 1A FAILS TO RUN CCW-MDP-FR-1B T
CCW MDP 1B FAILS TO RUN CCW-MDP-FS-1A T
CCW MDP 1A FAILS TO START CCW-MDP-FS-1B T
CCW MDP 1B FAILS TO START CCW-MDP-TM-1A T
CCW MDP 1A UNAVAILABLE DUE TO T&M CCW-MDP-TM-1B T
CCW MDP 1B UNAVAILABLE DUE TO T&M
LER-305/2005-002 52 Appendix C. Seismic Model and Calculations Modeling Assumptions:
1 AFW pump failures. Two cases are considered:
i) All three AFW pumps fail non-recoverably if CST fails due to a seismic event ii) Two MDPs fail with a probability of 0.2; TDP fails, if CST fails due to a seismic event.
2 Failure of AFW forces operators to implement feed and bleed (F/B), and eventually switchover to sump recirculation (REC). Failure of these functions are dominated by the operator errors.
Two cases are considered:
i) HEPs are the same as internal events (0.02 + 0.002 = 0.022).
ii) HEPs are higher by a factor of 2 and 4, respectively, in seismic bins 2 and 3.
3 CST HCLPF is low: it is assumed to be the same as the ceramic insulators. However, its failures in each seismic bin are considered to be independent of ceramic insulators.
4.
Three seismic bins, already defined in the KEWA-EE-312 are used. The initiating event frequencies of these bins are:
EQK-BIN-1 0.05-0.3 g 2.84E-04/year EQK-BIN-2 0.3-0.5 g 1.26E-05/year EQK-BIN-3
> 0.5 g 7.21E-06/year Total =
3.04E-04/year 5.
The failure probability of CST due to a seismic event in each bin is given as :
EQK-BIN-1 0.05-0.3 g 2.77E-02 EQK-BIN-2 0.3-0.5 g 5.72E-01 EQK-BIN-3 > 0.5 g 8.99E-01 These failure probabilities are based on the HCLPF value assumed in 3.
An event tree model, using the dominant sequences idnetified in the base case is constructed and is given in Figure C-1. This even tree model identifies sequences 4 and 5 as the core damage sequences for the plant condition case. This model applies to each seismic event bin modeled in the KEWA-EE-321 model (Reference 5).
An example of CDF quantification is given in Figure C-1a for case 1 for EQK-BIN-1.
LER-305/2005-002 53 The CDF for four cases are calculated as shown in Table C-1. The four cases are also defined in Table C-1.
LER-305/2005-002 54 Figure C-1 Event Tree Model Depicting CDF calculation for Plant Condition Seismic Event Occurs CST Fails AFW Fails Feed and Bleed Fails Switchover to recirculation fails Sequence End State 1
Base case 2
Base Case 3
Success 4
Core damage 5
Core damage Sum of sequence 4 and 5 is calculated in Table 1 for each seismic bin.
For example, for case 1 for bin 1, the calculation is as follows:
Figure C-1a.
Seismic Event Occurs (case 1)
CST Fails AFW Fails Feed and Bleed Fails Switchover to recirculatio n fails Sequence End State CDF 1
Base case EQK-BIN-1 2
Base Case 2.84E-04 3
Success 2.77E-02
~1 4
Core damage 1.57E-08 1
0.002 5
Core damage 1.57E-07 0.02 CDF =
1.73E-07
LER-305/2005-002 55 Table 1 Calculation of Seismic Contribution to AFW Plant Condition Case I.
All three AFW pumps fail, if CST fails. F/B and REC HEPs are the same as internal events Seismic Scenario SE Occurs CST Fails AFW Fails F/B or REC Fail CDF EQK-BIN-1 0.05-0.3 g 2.84E-04 2.77E-02 1
2.20E-02 1.73E-07 EQK-BIN-2 0.3-0.5 g 1.26E-05 5.72E-01 1
2.20E-02 1.58E-07 EQK-BIN-3
> 0.5 g 7.21E-06 8.99E-01 1
2.20E-02 1.43E-07 Sum =
3.04E-04 4.74E-07 Case II.
All three AFW pumps fail, if CST fails. F/B and REC HEPs are larger for seismic bins 2 and 3.
Seismic Scenario SE Occurs CST Fails AFW Fails F/B or REC Fail CDF EQK-BIN-1 0.05-0.3 g 2.84E-04 2.77E-02 1
2.20E-02 1.73E-07 EQK-BIN-2 0.3-0.5 g 1.26E-05 5.72E-01 1
4.40E-02 3.17E-07 EQK-BIN-3
> 0.5 g 7.21E-06 8.99E-01 1
8.80E-02 5.71E-07 Sum =
3.04E-04 1.06E-06 Case III.
MDPs fail with 0.2 probability, if CST fails. F/B and REC HEPs are the same as internal events Seismic Scenario SE Occurs CST Fails AFW Fails F/B or REC Fail CDF EQK-BIN-1 0.05-0.3 g 2.84E-04 2.77E-02 0.2 2.20E-02 3.46E-08 EQK-BIN-2 0.3-0.5 g 1.26E-05 5.72E-01 0.2 2.20E-02 3.17E-08 EQK-BIN-3
> 0.5 g 7.21E-06 8.99E-01 0.2 2.20E-02 2.85E-08 Sum =
3.04E-04 9.48E-08 Case IV.
MDPs fail with 0.2 probability, if CST fails. F/B and REC HEPs are larger for seismic bins 2 and 3.
Seismic Scenario SE Occurs CST Fails AFW Fails F/B or REC Fail CDF EQK-BIN-1 0.05-0.3 g 2.84E-04 2.77E-02 0.2 2.20E-02 3.46E-08 EQK-BIN-2 0.3-0.5 g 1.26E-05 5.72E-01 0.2 4.40E-02 6.33E-08 EQK-BIN-3
> 0.5 g 7.21E-06 8.99E-01 0.2 8.80E-02 1.14E-07 Sum =
3.04E-04 2.12E-07