ML050820207
| ML050820207 | |
| Person / Time | |
|---|---|
| Site: | Kewaunee  |
| Issue date: | 03/12/2005 |
| From: | Lambert C Nuclear Management Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| NRC-05-032 | |
| Download: ML050820207 (32) | |
Text
NMC t Committed to Ncer Ecle KEWAUNEE NUCLEAR POWER PLANT Operated by Nuclear Management Company, LLC March 12, 2005 NRC-05-032 U. S. Nuclear Regulatory Pommission ATTN: Document Control Desk Washington, D.C. 20555 Kewaunee Nuclear Power Plant Docket 50-305 License No. DPR-43 Kewaunee Containment Equipment Hatch Interference Data
Reference:
Letter from Mark A. Satorius (NRC Rill) to Craig Lambert (NMC),
"Preliminary Significance Determination For A Greater Than Green Finding (NRC Inspection Report 50-305/2004-09) - Kewaunee Containment Equipment Hatch Interference," dated February 18, 2005.
Nuclear Regulatory Commission (NRC) Inspection Report 50-305/2004-09 documented an issue associated with prompt closure of the containment equipment hatch at the Kewaunee Nuclear Power Plant (KNPP). In the above referenced letter, the NRC provided the Nuclear Management Company, LLC, (NMC) with the NRC's preliminary significance determination for the performance deficiency and offered NMC an opportunity to present our perspectives prior to finalization of the NRC's significance determination.
NMC has requested a Regulatory Conference to present our perspectives on the facts and assumptions used. This Regulatory Conference is scheduled for March 17, 2005, at the NRC Region III headquarters. Additionally the NRC encouraged NMC to submit supporting documentation for the requested Regulatory Conference before the conference.
Since the issuance of the Inspection Report, NMC has performed further analysis to better characterize the probabilistic risk assessment (PRA) assumptions and inputs.
Enclosed are the latest results of that work for use at the requested Regulatory Conference. Additional information, that may be helpful in assessing this issue, will be submitted within several days.
N490 Highway 42. Kewaunee, Wisconsin 54216-9511 Telephone: 920.388.2560
Document Control Desk Page 2 If you have any comments or questions please contact Mr. Gerald Riste of my staff at (920) 388-8424.
Summary of Commitments This letter contains no new commitments and no revisions to existing commitments.
Craig W. Lambert Site Vice-President, Kewaunee Nuclear Power Plant Nuclear Management Company, LLC Enclosures (1) cc:
Administrator, Region l1l, USNRC Project Manager, Kewaunee, USNRC Resident Inspector, Kewaunee, USNRC Public Service Commission of Wisconsin
ENCLOSURE 1 RISK ASSESSMENT FOR KEWAUNEE CONTAINMENT HATCH CLOSURE ISSUE Revision 4 - March 2005 29 pages follow
PRA APPLICATION DOCUMENTATION FORM PRA APPLICATION # 05-07 DATE March 12,2005 PRA MODEL REVISION: N/A PERSON(S) INVOLVED:
E. D. Coen T. L. Breene J. P. Masterlark J. F. Helfenberger
1.0 DESCRIPTION
Evaluate the risk of the Kewaunee containment hatch closure issue.
2.0 METHODOLOGY See attached 3.0 ASSUMPTIONS See attached 4.0 MODELS/CALCULATIONS See attached 5.0 RESULTS AND CONCLUSIONS See attached Responsible Persoon:_____
March 12. 2005 Technical Reviewer:
17 v "
March 12. 2005 Form GNP-01.41.02-1 Rev. D Date: NOV 25 2003 Page 7of 8
Risk Assessment for Kewaunee Containment Hatch Issue Revision 4 Summary of Dominant Scenario Loss of Offsite Power with Diesel Generator B Failure Failure Probability Loss of Offsite Power During Shutdown 0.189/Year Diesel Generator B Fails 0.0108 Core Damage Before Flow Restoration 0.068 Charging via TSC Diesel Fails 0.066 1 Equipment Hatch Closure Fails 0.37 Total Large Early Release Frequency (LERF) 3.40xIO-/year The time in question is the time that diesel generator A was out of service with the obstruction present (2.73 days).
Large Early Release Probability is:
LERP = 3.40xIO-/year
- 2.73 / 365 = 2.5x10 8 The condition of having an obstruction hampering containment hatch closure is of very low significance.
Page 2 of 29
Risk Assessment for Kewaunee Containment Hatch Issue Revision 4 Justification for Each Number Used in the Analysis I.
Loss of Offsite Power Occurs The LOSP frequency for a shutdown configuration, from Reference 1, is 1.89x I 0'/year II.
Diesel Generator B Fails The failure of diesel generator B is dominated by the following failure modes:
Failure Mode Probabilit Diesel Generator B Fails to Run (Unrecovered) 3.855x 10-Non-Recovery Probability 0.757 Diesel Generator B Fails to Run (Recovered) 2.92x10 O Diesel Generator B Fails to Start (Unrecovered) 9.231x10 3
Non-Recovery Probability 0.853 Diesel Generator B Fails to Start (Recovered) 7.87xl0 3 The failure to run and failure to start data are from plant-specific data from October 1995 through February 2005. The mission time is 1.628 hours0.00727 days <br />0.174 hours <br />0.00104 weeks <br />2.38954e-4 months <br />. This is based on the area under the recovery curve in Reference 1 and represents the probability weighted average of loss of offsite power recovery time. Diesel generator ventilation and air supply are counted as part of the diesel generator in this data. Support system probabilities were also examined, but they are not dominant because failure of multiple components is required.
Operators are directed by procedure to make attempts to recover diesel generators. If a diesel fails with a loss of offsite power, control room lighting is lost, which is a compelling indication. The control room and diesel rooms are equipped with emergency lighting, so light would be available.
During the time of concern there was a "super crew" (a double operating crew) and maintenance personnel available at all time.
The sum of the recovered run and start failure probabilities is 1.08x10,2.
III.
Core Damage Before Flow Restoration Reference 3 shows that core uncovery occurs at 5.44 hours5.092593e-4 days <br />0.0122 hours <br />7.275132e-5 weeks <br />1.6742e-5 months <br /> for the reactor vessel head studs tensioned case and no earlier than 9.0 hours0 days <br />0 hours <br />0 weeks <br />0 months <br /> for the studs detensioned case.
Once power is restored, RHR cooling would be restored. The duration of a loss of offsite power is based on data from Reference 1. For the studs tensioned case, a non-restoration probability of 0.077 is used. This value is for 4.94 hours0.00109 days <br />0.0261 hours <br />1.554233e-4 weeks <br />3.5767e-5 months <br />, allowing 30 minutes for restoration of power from the grid to safeguards components. For the studs detensioned case, a non-restoration probability of 0.038 is used. This value is for 8.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br />, allowing 30 minutes for restoration of power from the grid to safeguards components. The 30 minutes is a conservative value, based on operator interviews and validated on the Kewaunee simulator.
The time with studs tensioned was from 0127 on 10/12 to 0300 on 10/14, which is 49.55 hours6.365741e-4 days <br />0.0153 hours <br />9.093915e-5 weeks <br />2.09275e-5 months <br /> (see exposure time discussion below for details). The time with studs detensioned was from 0300 to 1855 on 10/12, which is 15.9167 hours0.106 days <br />2.546 hours <br />0.0152 weeks <br />0.00349 months <br />. The average non-restoration probability for the entire interval is:
Page 3 of 29
Risk Assessment for Kewaunee Containment Hatch Issue Revision 4 0.077 x 49.55 + 0.038 x 15.9167 = 0.068 49.55 + 15.9167 IV.
Charging via Technical Support Center Diesel Generator Fails One charging pump is capable of supplying 60 gallons per minute (gpm) of flow. An NMC calculation performed using the methodology of Reference 4 shows that at 50 hours5.787037e-4 days <br />0.0139 hours <br />8.267196e-5 weeks <br />1.9025e-5 months <br /> after shutdown, 47 gpm of flow is sufficient to remove decay heat. The scenario in question occurred at least 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> after shutdown, so one charging pump is sufficient to remove decay heat.
The thermal hydraulic calculations in Reference 3 do not include charging. In these cases, the total boiloff rate remains below the capacity of one charging pump. In reality, once charging is established it will reduce the boiloff rate and eventually stop boiling altogether due to the influx of cool RWST water.
There are two parts to failure probability. The first is the equipment failures and the second is operator errors. The dominant equipment failures are:
Failure Mode Probability I
TSC Diesel Generator Fails to Run 5.560x 10-3 TSC Diesel Generator Fails to Start 1.504xl0V The TSC diesel was in service for the entire time in question. The failure to run probability is based on a Bayesian update of generic data from plant specific data from Reference 2. The failure to start probability is based on plant specific data from October 1995 through February 2005. The mission time is 1.628 hours0.00727 days <br />0.174 hours <br />0.00104 weeks <br />2.38954e-4 months <br />. This is based on the area under the recovery curve in Reference 1 and represents the probability weighted average of loss of offsite power recovery time. Diesel generator ventilation and air supply are considered part of the diesel generator in this data. The sum of these is 2.060x 10-2.
Support system probabilities and charging failures were also examined, but they are not dominant because failure of multiple components is required.
There are two important human error probabilities (HEPs). One is to establish power for the TSC diesel generator to one charging pump. The HEP for this is 3.697x10-2 (See Appendix A for details).
The second HEP is a latent failure to restore the TSC diesel after testing. The HEP for this failure is 8.558x l03. This HEP is unchanged from the current PRA model.
The total failure probability for this node is 6.613x10- 2.
V.
Equipment Hatch Closure Fails The probability of a failure to close the equipment hatch with an obstruction in place is 0.37.
Appendix A describes these HEPs in detail.
VI.
Exposure Time The following time line, from logs kept during the event, shows some of the key times in the scenario. When the track was installed the Reactor Coolant System (RCS) was full, both pressurizer Page 4 of 29
Risk Assessment for Kewaunee Containment Hatch Issue Revision 4 safety valves were in place, the reactor head was fully tensioned and the steam generators were filled to normal level.
Event Date Time Start of Track Installation 10/11 1245 Diesel Generator A out of Service for Surveillance but Available.
10/11 1327 Pressurizer Safety Valve Removed 10/11 1430 Diesel Generator A Returned to Service 10/11 1510 Diesel Generator B out of Service 10/11 1604 Diesel Generator B Returned to Service 10/11 1947 Started Reactor Coolant System Draindown 10/12 0032 Diesel Generator A out of Service 10/12 0127 Completed Reactor Coolant System Draindown 10/12 0502 Steam Generator A Filled to Wet Layup 10/12 1617 Steam Generator B Filled to Wet Layup 10/12 2340 Reactor Vessel Stud Detensioning Begins 10/13 1045 Reactor Vessel Stud Detensioning Ends 10/14 0300 Track is Removed 10/14 1855 Prior to 1604 on 10/11, Both diesel generators were available. As a result, the failure probability of a single diesel generator failure, 0.0108 as described in Section II above, would be replaced by the probability of both diesels failing, which is about 8x 10-4, based on a common cause f3 of 0.07.
Diesel generator A was removed from service from 1327 to 1510 in 10/11 This out of service time was due to SP-33-1 10, SI sequencer test. The diesel generator was actually available because it is running during this test. If a loss of power would occur during the test, power would not be interrupted from the safeguards electrical buses.
During the period from 1604 to 1947 on 10/11, (0.1549 days) Diesel Generator B was out of service.
Since the duration of the out of service time was less than the calculated time to core uncovery, this time is not considered in the analysis.
During the period from 0127 on 10/12 to 0300 on 10/14, (2.065 days) Diesel Generator A was out of service, reactor vessel head studs were tensioned and the obstruction was in place in the equipment hatch. Reference 3 shows that during this time, core uncovery is prevented if injection is restored within 5.44 hours5.092593e-4 days <br />0.0122 hours <br />7.275132e-5 weeks <br />1.6742e-5 months <br />.
During the period from 0300 to 1855 on 10/14, (0.663 days) Diesel Generator A was out of service, reactor vessel head studs were detensioned and the obstruction was in place in the equipment hatch.
Since Diesel Generator A was being overhauled and was disassembled, no credit is taken for recovery. Reference 3 shows that during this time, core uncovery is prevented if injection is restored within 9 hours1.041667e-4 days <br />0.0025 hours <br />1.488095e-5 weeks <br />3.4245e-6 months <br />.
Other Scenarios:
Small Break LOCA The scenario here is a small beak LOCA due to a flow diversion, followed by a failure to diagnose the event and isolate the diversion path.
Page 5 of 29
Risk Assessment for Kewaunee Containment Hatch Issue Revision 4 A small break LOCA due to a flow diversion at shutdown conditions has an initiating frequency of 0.083 from generic shutdown data, less than that for a loss of offsite power. Operators must fail to isolate the diversion path (HEP = 0.071), must fail to provide charging using the normal power supply (safeguards power) (HEP = 0.002), and bleed and feed via safety injection must fail (HEP = 0.0035) for core damage to occur. Since there are multiple independent systems available and no local actions are needed to provide power, the core damage frequency is about 4xl0-8/year, which is almost two orders of magnitude below that of a loss of power.
During the time that RCS draindown was occurring, from 0032 to 0502 on 10/12, the small LOCA frequency would be somewhat higher. But since the time period was short and the risk associated with a small break LOCA is low, the risk due to draindown is insignificant.
Interfacing Systems LOCA An interfacing LOCA is not affected by a delay in closing the equipment hatch, since containment is bypassed altogether.
System Initiators Loss of RHR cooling, loss of component cooling and loss of service water have the same effect. RHR cooling is interrupted and would need to either be reestablished or an alternate source of cool water, the RWST must be used for injection. The initiating frequencies for these events, 0.025 for loss of RHR (from generic shutdown data), 0.034 for loss of component cooling (from the at-power model) and 0.0043 for loss of service water (from the at-power model). These are all less than that for a loss of offsite power. Operators must fail to recover the system (HEP = 0.021), must fail to provide charging using the normal power supply (safeguards power) (HEP = 0.002), and bleed and feed via safety injection must fail (HEP = 0.0035) for core damage to occur. Since there are multiple independent systems available and no local actions are needed to provide power, the core damage frequency is about 8x 1 0-9/year, which is several orders of magnitude below that of a loss of power.
A single train loss of RHR is also included in the model, with an initiating frequency of 0.084, greater than the loss of a complete system, but still less than the loss of offsite power. This initiator has a simple recovery, to start the standby train. If this recovery fails, the alternate sources discussed above are still available. During the entire period that containment closure was hampered, both RHR pumps were available.
These are the only initiators considered because they are the only initiators in the internal events shutdown model that could affect availability of Residual Heat Removal.
Qualitative Evaluation of External Events Seismic The diesel generators have a mean seismic capacity of 1.57g, from the Kewaunee Seismic PRA (SPRA),
with a standard deviation of 0.46g. This is considerably higher than that used for containment in the SPRA (0.64 and 0.3, respectively). If a seismic event severe enough to damage containment occurred, hatch closure would be irrelevant. If a less severe seismic event occurred, diesel generators would be available, so the scenario discussed in this report would not occur unless a random failure occurred.
Page 6 of 29
Risk Assessment for Kewaunee Containment Hatch Issue Revision 4 Since the frequency of a seismic event at Kewaunee is small (1.lxlO4/year for a design basis earthquake) compared to that of a random loss of offsite power with no recovery (1.3x102/year), the core damage frequency for a seismic event followed by random failures is insignificant.
Fire The initiating frequency for any fire in the plant would be considerably smaller than the internal events values used in this report. The only fires that could potentially result in a significant core damage frequency are those that result in a loss of offsite power and the failure of diesel generator B.
In the analysis done for the fire PRA, there are four rooms that contain cabling to both offsite power supplies and diesel generator B. These rooms are:
- 1. The CO2 Storage Tank Room
- 2. The Bus 61 and 62 Room
- 3. The Diesel Generator B Room
- 4. The Auxiliary Feedwater Pump B Room The CO2 storage tank room and bus 61 and 62 room can be eliminated from the analysis, because all fire sources in the room were analyzed but none resulted in damage to the cabling in concern.
The diesel generator B room was posted as "Protected Equipment" during the entire period in question. This means that no work would be allowed in the room without permission from the Shift Manager. This means that the major sources for fires in the room (diesel generator oil and transient combustibles) can be eliminated, resulting in a fire frequency of 4.5xl10 4/year. This frequency is a factor of 4 below the random frequency of a loss of offsite power with a diesel generator failure (2.0xl 0 3/year). That, coupled with the automatic detection and suppression in room, makes the frequency of a fire in this room negligible.
The auxiliary feedwater pump B room was examined for the Kewaunee fire PRA. This room has automatic detection and a water suppression system. The resulting initiating event frequency of a fire with a failure of suppression and detection is 3.27xlO4/year. Coupled with equipment hatch closure, the large early release frequency is 1.2 lx 1 O-6/year. This is a factor of 2 below the internal events value.
Other High winds, tornadoes, external floods and other external events were screened out of the Kewaunee PRA as not important, due to their low initiating frequency. The initiating frequencies are well below the ones already examined in this report.
Page 7 of 29
Risk Assessment for Kewaunee Containment Hatch Issue Revision 4 References
- 1. NUREG-CR/INEEL/EXT-04-02326, "Evaluation of Loss of Offsite Power Events at Nuclear Power Plants: 1986 - 2003 (Draft)," October 2004.
- 2. NUREGICR-5500 Volume 5 "Emergency Diesel Generator Power System Reliability - 1997-2003,"
September 2004.
- 3. Westinghouse Electric Company Report, "Kewaunee Response to a Potential Loss of RHR Cooling Due to a Loss of All AC Power While at Reduced Inventory Conditions" March 2005.
Page 8 of 29
Risk Assessment for Kewaunee Containment Hatch Issue Revision 4 Appendix A Human Event Probability Calculations Page 9 of 29
Risk Assessment for Kewaunee Containment Hatch Issue Revision 4 HEP 35--CH2-SD---HE HEP Description Establish Charging Flow while shutdown Revision Date 12/20/2004 Evaluator GE Baldwin Reviewer E. Coen Operations Review S. Cieslewicz Operations Simulator observation and operator interviews conducted from 9/25/02 to 6/3/03 The operators are directed by ECA-0.0 to establish charging flow using the TSC Diesel Scenario and Charging Pump C. The operators take several steps to ensure a successful re-energization of Bus 52. Re-energizing Bus 52 allows the starting of Charging Pump A or C that provides makeup to RCS.
The operators are directed by ECA-0.0 to establish charging flow using the TSC Diesel Event and Charging Pump C. The operators take several steps to ensure a successful re-Description energization of Bus 52. Re-energizing Bus 52 allows the starting of Charging Pump A or C that provides makeup to RCS.
The following assumptions are made:
Due to training the operator will use ECA-0.0 to establish charging
- The TSC Diesel started and properly energized Bus 46.
Assumptions Charging Pump A or C is available.
for the Event Operations department has established "super crews" and thus has additional personnel to deal with event.
- Time is available to re-perform all steps of the procedure to recover from any error.
50 gpm is enough injection to make up for boil off and refill of the RCS.
It is assumed that the operators will have 5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> to initiate RCS refill to prevent core Timing uncover per Kewaunee Response to a Potential Loss of RHR Cooling Dite to a Loss of4All ialm*i AC Powver WKiile at Reduced Imventory Conditions (March 2005). Based on operator lysis interview, it is estimated that the operators will start the alignment in approximately 15 minutes and will have initiated RCS refill in 36 minutes.
Success Greater than 50 gpm charging flow established to RCS.
Criteria References ECA-0.0 Used Cognitive It is assumed proper place keeping is used.
Cognitive Recovery It is assumed STAR self-checking is used.
Assumptions Page 10 of 29
Risk Assessment for Kewaunee Containment Hatch Issue Revision 4 Execution Assumptions Time to recover from an unsuccessful start exist.
Execution Recovery None Assumptions Page 11 of 29
Risk Assessment for Kewaunee Containment Hatch Issue Revision 4 35--CH2-SD---HE, Establish Charging Flow while shutdown Basic Event Summary Analyst::
GEB Rev. Date:;:
03/08/05 Cognitive Method:
-- CDBTMITHERP Table 1: 35-CH2-SD-HE
SUMMARY
Analysis Results:
without Recovery with Recovery Pco-3.0e-03 1.5e-03 Pexe 1.1e-01 3.5e-02 Total HEP 3.7e-02 Error Factor',.:
5 HFE Scenario
Description:
The operators are directed by ECA-0.0 to establish charging flow using the TSC Diesel and Charging Pump C. The operators take several steps to ensure a successful re-energization of Bus 52. Re-energizing Bus 52 allows the starting of Charging Pump A or C that provides makeup to RCS and stops RXCP seal leakage.
Related Human Interactions:
None Performance Shaping Factors:
Optimal stress was assigned due to being in a shutdown condition and the additional support personnel available to assist the operator.
Note: Due to the time of core uncovery, additional time is available to recover and/or correct actions taken.
Procedure and step governing HI:
ECA-0.0. step 1-16 with steps 6, 12,13, 14, and 16 being necessary to be completed successfully to complete the task.
Training:.
None X
Classroom Frequency: 1 X
Simulator Frequency: 1 Degree of Clarity of Cues & Indications:
Very Good X
Average Poor Page 12 of 29
Risk Assessment for Kewaunee Containment Hatch Issue Revision 4 Human-Machine Interface:.- >.;!.
-; z
.- 1 r -:
-rP, -
X Control Room Panels X
Local Control Panels X
Local Equipment Special Requirements:':
Tools Parts Clothing Required Required Required Adequate Adequate Adequate Available Available Available Type of Response:
Skills X
Rule Knowledge Complexity'of Response':-..
Cognitive Execution Complex X
Complex X
Simple Simple Entvironment:- -
Lighting Heat/Humidity Normal X
Normal X
Emergency Hot / Humid Portable Cold Radiation Atmosphere X
Background
X Normal Green Steam Yellow Smoke Red Respirator required Equipment Accessibility:
Location Accessibility X
Control Room Front Panels Accessible Control Room Back Panels Hot Shutdown Panels X
Auxiliary Building Accessible Electrical Building Containment Pump house Switchyard
,Stress:
Optimum (Low)
X Moderate Extreme (High)
Page 13 of 29
Risk Assessment for Kewaunee Containment Hatch Issue Revision 4 Cognitive Unrecovered 35--CH2-SD--- HE Cue:
Loss of offsite power with Bus 5 and Bus 6 de-energized.
TSW 300 Tdelay 15.3 1/2 0
T M 20.5 I reversible Cue DamageState t=o Unit: Minutes Refer ence for System Time: Core Uncover calculation Reference for Manipulation Time: Operator interviews and Simulator observation Duration of time window available for action (TW): 263.50 Minutes Table 2: 35-CH2-SD-HE COGNITIVE UNRECOVERED Pc Failure Mechanism Branch HEP.
Pca: Availability of Information a
neg.
Pcb: Failure of Attention h
neg.
Pc,: Misread/miscommunicate data a
neg.
Pcd: Information misleading a
neg.
Pce: Skip a step in procedure c
3.0e-03 Pcf: Misinterpret instruction a
neg.
Pcg: Misinterpret decision logic I
neg.
Pch: Deliberate violation a
neg.
Sum of Pc, through Pch = Initial Pc =
3.0e-03 Page 14 of 29
Risk Assessment for Kewaunee Containment Hatch Issue Revision 4 pca: Availability of information Indication Avail in CR Indication l Warning!Alternate Training on I
CR I
Accurate I
in Procedure I
Indicators (a) neg.
F (b) neg.
(c) neg.
l__
[(d) 1.5e-03 (e) 5.0e-02 (f) 5.De-01 (g) -*
Yes No pcb: Failure of attention Low vs. Hi l Check vs. Monitor Front vs. Back l
Alarmed vs.Not l
Workload I
I Panel I
Alarmedn Low
- 1. Chlice Front Check (a) neg.
Back l(b) 1.5e.04 (c) 3.0e-03 Front (d)1.5e.04 Monitor (e) 3.0e-03 Back (f) 3.0e-04 (g) 6.0e-03 Front
- - (h) neg.
Check (i) neg.
Back
()7.5e-04 (k) 1.5e-02 Front (I) 7.5e-04 Monitor I(m) 1.5e-02 Back (n) 1.5e-03 (o) 3.0e-02 Hi Page 15 of 29
Risk Assessment for Kewaunee Containment Hatch Issue Revision 4 pcc: Misread/miscommunicate data Indicators Easy to l
Good/Bad Indicator Formal I
Locate I
I Communications I
'[
I
-l Yes No (a) neg.
(b) 3.0e-03 (c) 1.Oe-03 (d) 4.0e-03 (e) 3.0e-03 (f) 6.0e-03 (g) 4.0e-03 (h) 7.0e-03 I
I pcd: Information misleading All Cues as Stated l Wamring of Specific Training General Training I
I Differences I
I I
_______------------------------- (a) neg.
Yes (b) 3.0e-03 No (c) 1.0e-02 (d) 1.0e-41 (e) 1.0 pce: Skip a step in procedure Obvious vs.
l Single vs. Multiple Graphically l Placekeeping Aids Hidden I
I Distinct I
(a) 1.0e-03 (b) 3.0e-03 (c) 3.0e-03 (d) 1.0e-02 F
(e) 2.0e-03 Yes r
(f) 4.0e-03 No (g) 6.0e-03 (h) 1.3e-02
-(i) 1.0e-01 Page 16 of 29
Risk Assessment for Kewvaunee Containment Hatch Issue Revision 4 pcf: Misinterpret instruction Standard or All Required Training on Step Ambiguous wording Information l
(a) neg.
r(b) 3.0e-03 (c) 3.0e-02 No l(d) 3.0e-03 (e) 3.0e-02 (f) 6.0e-03 (g) 6.0e-02 pcg: Misinterpret decision logic NOT' Statement
'AND' or "OR' Both 'AND' &
l Practiced Scenario ll Statement l
'OR' ll (a) 1.6e-02 (b) 4.9e.02 (c) 6.0e-03 (d) 1.9e.02 (e) 2.0e-03 (f) 6.0e-03 Yes (g) 1.0e-02 No
[(h) 3.1e-02 (i) 3.0e-04
- 0) 1.0e-03 (k) neg.
(I) neg.
pch: Deliberate violation Belief in Adequacy l Adverse Reasonable l
Policy of of Instruction I Consequence if Alternatives
'Verbatim' (a) neg.
Yes (b) 5.0e-1 No r
(c) 1.0 (d) neg.
(e) neg.
Page 17 of 29
Risk Assessment for Kewaunce Containment Hatch Issue Revision 4 Cognitive Recovery 35--CH2-SD---HE Table 3: 35-CI12-SD-TIE COGNITIVE RECOVERY P.
Cb-ne. NC1.
ne g.
>N C
Final Initial HEP Z '
-~
c i:>
O(
Value U WO CfWla)
U2)
W alu PDI:
0e Pc,:
neg.
-NC X
1.0 PCb:
neg.
NC 1.0 a c:
neg.
-NC
-1.0
- PCd:
neg.
-NC
-1.0 Pce:
3.0e-03 X
5.0e-01 5.0e-01 1.5e-03 Pcf:
neq.
-NC 1.0 Pc,:-'
neg.
NC 1.0 Pch:
neg.
NC 1.0 Sum of Pc; through PCh -
Initial PC =I 1.5e-03 Recovery Factors identified:
Super crews (double crews) are used during the outage so extra crew would be present.
Page 18 of 29
Risk Assessment for Kewaunee Containment Hatch Issue Revision 4 Execution Unrecovered 35--CH2-SD---HE Table 4: 35-CH2-SD-HE EXECUTION UNRECOVERED
. Step Omission
.Commission-Total
-.,.Table lItem -
Stress I Stress.
Table.,
Item-,
Stress:.
Stress Over J
Per Step No.
HEP Ref. -
Ref.
E/MWO, Value HEP Ref.
. Ref. -
E/M/O Value
- Ride, Step Step 6 4.3E-4 20-7b 1
M 2
1.3E-3 20-12 3
M 2
3.5e-03 Actions: Place the following equipment in pullout Comments: Steps 1-4 and 10 are verification of auto actions that are assumed to have occurred. Steps 5 and 8 are assumed unsuccessful. Steps 7 and 9 are required to migate the overall plant problem, they are not required to sucessfully establish charging flow.
Step 12 1.3E-3 20-7b 2
M 2
1.3E-3 l 20-12 4
M 2
5.2e-03 Actions: Open breaker 15201 Comments:
Step 13.a I
1.3E-3 20-7b 2
M 2
1.3E-3 l 20-12 3
M 2
5.2e-03 Actions: Place the following control switches to OFF Comments:
Step 13.b I
1.3E-3 I 20-7b 2
M 2
1.3E-3 i 20-12 3
M 2
5.2e-03 Actions: Place the following control switches to pullout Comments: Steps 13.c is required to migate the overall plant problem, it is not required to sucessfully establish charging flow.
Step 13.d 1.3E-3 20-7b 2
M 2
neg.
l 20-12 la I
M 2
2.6e-03 Actions: Open the following Relay Room panel doors Comments:
Step 14.b.1 I
1.3E-3 I 20-7b 2
M 2
3.8E-3 l 20-12 12 M
2 1.0e-02 Actions: Open Breaker 14606 Comments: For Step 14.a see 05B-MU3A-SBO-HE Step 14.b.2 I
1.3E-3 I 20-7b 2
M 2
3.8E-3 l 20-12 12 l
M 2
1.0e-02 Actions: Close Breaker 14607 Comments:
Step 14.c.1 1.3E-3 I 20-7b 2
M 2
3.8E-3 l 20-12 12 M
2 1.Oe-02 Actions: Open the following breakers of MCC-52C Comments:
Step 14.c.2 I
1.3E-3 L 20-7b 2
M 2
6.3E-3 l 20-12 11 M
2 1.5e-02 Actions: Open the following breakers of BRA-127 Comments:
Step 14.c.3 I
1.3E-3 I 20-7b 2
M 2
neg.
l 20-12 la M
2 2.6e-03 Actions: Block open the following doors Comments:
Step 14.d.1 I
1.3E-3 I 20-7b 2
M 2
3.8E-3 l 20-12 12 M
2 1.0e-02 Actions: Open the following breakers of MCC-52E Comments:
Step 14.e.1 I
1.3E-3 I 20-7b 2
M 2
3.8E-3 l 20-12 12 M
2 1.0e-02 Actions: Open the following breakers of Bus 52 Comments:
Step 14.e.2 I
1.3E-3 I 20-7b 2
M 2
3.8E-3 l 20-12 12 M
2 1.0e-02 Actions: Notify the Control Room and Close Breaker 15210 Comments:
Step 15 l 1.3E-3 I 20-7b 2
M 2
neg.
j 20-11 8
M 2
2.6e-03 Actions: Verify Bus 52 Energized Comments:
Step 16.a I
1.3E-3 20-7b 2
M 2
1.3E-3 l 20-12 3
M 2
5.2e-03 Actions: Close CVC-212 Comments:
Step 16.b I
1.3E-3 20-7b 2
M 2
1.3E-3 l 20-12 3
M 2
5.2e-03
(
Page 19 of 29
Risk Assessment for Kewaunec Containment Hatch Issue Revision 4 Actions: Close CVC-7 Comments: Step 16.c is not required since it will occur automatically at 5% VCT level if bus 52 is energized.
Step 16.d l1.3E-3 l20-7b l 2
M 2
2.7E-3 l 20-12 9
M 2
8.0e-03 Actions: Place Charging Pump A Controller to minimum speed Comments:
Step 16.e -Recovery I
1.3E-3 I 20-7b l 2
M 2
1.3E-3 l 20-12 4
M 2
5.2e-03 Actions: Start Charging Pump A to establish RXCP seal injection flow Comments:
Step 16.e I
1.3E-3 I 20-7b l 2
T M
2 1.3E-3 T 20-12 4
M 2
5.2e-03 Actions: Start Charging Pump A to establish RXCP seal injection flow Comments:
Step 16.f I
1.3E-3 I 20-7b l 2
M 2
1.3E-3 l 20-12 3
M 2
5.2e-03 Actions: Slowly open CVC-7 and control charging flow to restore PRZR level Comments:
Step 16.f-Recovery.
I 1.3E-3 I 20-7b 1 2
I M
1 2
1.3E-3 i 20-12 3
M 2
5.2e-03 Actions: Slowly open CVC-7 and control charging flow to restore PRZR level Comments:
Step 31.a RNO a.5 1.3E-3 20-7b 2
M 2
neg.
l 20-11 8
M 2
2.6e-03 Actions: Go to step 15 Comments:
Recovery 1.3E-3 20-7b 2
M 2
1.3E-3 l 20-12 4
M 2
5.2e-03 Actions: No power to start Charging pump Comments: Due to being Shutdown, additional time Is available to recover TCS Diesel and try a restart by a review of the required step.
Page 20 of 29
Risk Assessment for Kcwaunce Containment Hatch Issue Revision 4 Execution Recovery 35--CH2-SD---HE Table 5: 35-CI12-SD-IIE EXECUTION RECOVERY Critical Step No.
Recovery StepNo.
'Action
-HEP(
r:
HEP(Rec)
Dep.'
Cond HEP Tot HPrt)(Rec)
Step' Step 6 Place the following equipment in pullout 3.5e-03 5.2e-04 Recovery No power to start Charging pump 5.2e-03 MD 1.5e-01 Step 12 Open breaker 15201 5.2e-03 7.7e-04 Recovery No power to start Charging pump 5.2e-03 MD 1.5e-01 Step 13.a Place the following control switches to OFF 5.2e-03 7.7e-04 Recovery No power to start Charging pump 5.2e-03 MD 1.5e-01 Step 13.b Place the following control switches to pullout 5.2e-03 7.7e-04 Recovery No power to start Charging pump 5.2e-03 MD 1.5e-01 Step 13.d Open the following Relay Room panel doors 2.6e-03 3.8e-04 Recovery No power to start Charging pump 5.2e-03 MD 1.5e-01 Step 14.b.1 Open Breaker 14606 1.0e-02 1.5e-03 Step 14.b.2 Close Breaker 14607 1.0e-02 MD 1.5e-01 Step 14.b.2 Close Breaker 14607 1.0e-02 1.5e-03 Step 14.c.1 Open the following breakers of MCC-52C 1.0e-02 MD 1.5e-01 Step 14.c.1 Open the following breakers of MCC.52C 1.0e-02 1.5e-03 Recovery No power to start Charging pump 5.2e-03 MD 1.5e-01 Step 14.c.2 Open the following breakers of BRA-127 1.5e-02 2.2e 03 Recovery No power to start Charging pump 5.2e-03 MD 1.5e-01 Step 14.c.3 Block open the following doors 2.6e-03 3.8e-04 Recovery No power to start Charging pump 5.2e-03 MD 1.5e-01 Step 14.d.1 Open the following breakers of MCC-52E 1.0e-02 1.5e-03 Recovery No power to start Charging pump 5.2e-03 MD 1.5e-01 Step 14.e.1 Open the following breakers of Bus 52 1.0e-02 1.5e-03 Recovery No power to start Charging pump 5.2e-03 MD 1.5e-01 Step 14.e.2 Notify the Control Room and Close Breaker 15210 1.0e-02 1.5e-03 Step 15 Verify Bus 52 Energized 2.6e-03 MD 1.5e-01 Step 15 Verify Bus 52 Energized 2.6e-03 3.8e-04 Step 31.a RNO a.5 Go to step 15.
2.6e-03 MD 1.5e-01 Step 16.a Close CVC-212 5.2e-03 7.5e-04 Step 31.a RNO a.5 Go to step 15 2.6e-03 MD 1.5e-01 Step 16.b Close CVC-7 5.2e-03 2.6e-03 Step 16.f Slowly open CVC-7 and control charging flow to restore PRZR 5.2e-03 HD 5.0e-01 le v e l I
I_
I__
Page 21 of 29
Risk Assessment for Kewaunee Containment Hatch Issue Revision 4 Step 16.d Place Charging Pump A Controller to minimum speed 8.0e-03 4.0e-03 Step 16.e -Recovery Start Charging Pump A to establish RXCP seal injection flow 5.2e-03 HD 5.0e-01 Step 16.e -
Start Charging Pump A to establish RXCP seal injection flow 5.2e-03 2.6e-03 Recovery Step 31.a RNO a.5 Go to step 15 2.6e-03 HD 5.0e-01 Step 16.e Start Charging Pump A to establish RXCP seal injection flow 5.2e-03 2.6e-03 Step 31.a RNO a.5 Go to step 15 2.6e-03 HD 5.0e-01 Step 1 6.f Slowly open CVC-7 and control charging flow to restore PRZR 5.2e03 2.6e-03 level Step 31.a RNO a.5 Go to step 15 2.6e-03 HD 5.0e-01 Step 16.f -
Slowly open CVC-7 and control charging flow to restore PRZR 5.2e-03 5.2e-03 Recovery level I
I Total Unrecovered:-
1.le-1
-Total Recovered:
3.5e-02 Page 22 of 29
Risk Assessment for Kewaunee Containment Hatch Issue Revision 4 89-OBC DR-HE DescriptOperator Fail to close HEP 89.~MAD..EHEP Description Containment Door with obstruction Revision Date 2/22/2005 Evaluator GE Baldwin Reviewer J. Masterlark Operations Review B. Gauger Operations I..
Input S
Interviews and Time line for closure Scenario A station blackout has occurred with fuel in the core and the equipment door open.
Operations directs the closure of the equipment door.
A station blackout has occurred with fuel in the core and the equipment door open.
Event Operations directs the closure of the equipment door. Maintenance closes the equipment Description door with assigned personnel but an obstacle is present. Maintenance removes the obstacle and then proceeds to close the equipment door.
The following assumptions are made:
- The obstacles present can be removed by any available means.
p
- Maintenance people are assigned and familiar with task Assumptionst Procedure is present, reviewed, and placekeeping used
- A sense of urgency is present
- Lighting from outside or other portable lighting is adequate to perform actions.
- Atmosphere is hot and humid but not prohibitive.
Action time is based an interviews of assigned and experienced personnel as well as plant logs. Time analysis is contained in the scenario timeline for this event. Total time was limited to an average Containment temperature of 1200 F based on NUREG/CR-6143, Timing Evaluation of Potential Severe Accidents During Low Power and Shutdown Operations at Analysis Grand Gulf Unit 1. This occurs at 193 minutes per Kewaunee Response to a Potential Loss ofRHR Cooling Due to a Loss ofAll AC Powver Widle at Reduced Inventory Conditions (March 2005) but time was reduced to 180 minutes to allow 13 minutes for egress. [Grand Gulf is a GE plant with an inside hatch with 20 bolts.]
Success Containment Equipment Door is closed.
Criteria References CMP-89A-02 Used Cognitive None Assumption Cognitive Recovery None Assumptions Execution Assumptions It is assumed door is position for quick closure.
Page 23 of 29
Risk Assessment for Kewaunee Containment Hatch Issue Revision 4 Execution It is assumed that moving the rear of the rail system has a higher dependence due to time eAssumtions proximity and being less visible than the front part of the rail.
Page 24 of 29
Risk Assessment for Kewaunee Containment Hatch Issue Revision 4 0.
89-OBCMTNTDR-HE, Operator Fail to close Containment Door with obstruction Basic Event Summary Analyst:
GE Baldwin I Rev. Date:'-
03/08/05 Cognitive Method:;
HCRJOREITHERP Table 6: 89-OBCNITNTDR-HE
SUMMARY
Analysis Results:
without Recovery with Recovery
Description:
A station blackout has occurred with fuel in the core and the Containment equipment door open.
Operations directs the closure of the Containment equipment door.
Related Human Interactions:
None Performance Shaping Factors:
Extreme stress due to adverse working conditions and potential consequences of the failure. Additionally task performers have limited practice and resources to complete task. Potential for other failures also exist.
Best Estimate for time. Training was provided during pre-job brief.
Procedure and step governing HI:
CMP-89A-02, Step 4.4 Training:
None X
Classroom Frequency: 1 Simulator Degree of Clarity of Cues &' Indications:-,,-
X Very Good Average Poor Human-Machine Interface: -
Control Room Panels Page 25 of 29
Risk Assessment for Kewaunee Containment Hatch Issue Revision 4 Local Control Panels X
Local Equipment Special Requirements:
Tools Parts Clothing X
Required Required X
Required X
Adequate Adequate X
Adequate X
Available Available X
Available IType of Response:
X Skills Rule Knowledge lComRnplexity of Response Cognitive Execution X
Complex Complex Simple X
Simple Environment:',
Lighting Heat/Humidity Normal Normal Emergency X
Hot I Humid X
Portable Cold Radiation Atmosphere
Background
Normal X
Green X
Steam Yellow Smoke Red Respirator required lEquipment Accessibility:
Location Accessibility Control Room Front Panels Control Room Back Panels Hot Shutdown Panels Auxiliary Building Electrical Building X
Containment With Difficulty Pump house Switchyard lStress::-"
Optimum (Low)
Moderate X
Extreme (High)
Page 26 of 29
Risk Assessment for Kewaunee Containment Hatch Issue Revision 4 Cognitive 89-OBCMTNTDR-HE Cue:
Directed to close Containment Equipment Door by operations.
t=
l'Unit:
Minutes Refer ence for System Time: Kewaunee Response to a Potential Loss of RHR Cooling Due to a Loss of All AC Power While at Reduced Inventory Conditions (March 2005) and NUREG/CR-6143 Reference for Manipulation Time: Time line Duration of time window available for action (TW): 24.00 Minutes Sigma Decision Tree.'.,
Skill vs. Rule Procedures Trainin Stress X
Skill Yes Yes Yes Rule X
No X
No X
No Sigma: 8.0e-01 HEP: 3.2e-01 Page 27 of 29
Risk Assessment for Kewaunee Containment Hatch Issue Revision 4 Execution Unrecovered 89-OBCMTNTDR-HE Table 7:89-OBCMITNTDR-IIE EXECUTION UNRECOVERED SteP Omission Commission Total
- Table, Item
- Stress, Stress Table IItem -
Stress Stress -
Over
- Per Step No.
HEP Ref.
Ref.
EJM/O Value HEP *-
Ref.
Ref.
E/MIO Value Ride Step -
4.4.1 1.3E-3 20-7 1
E 5
6.3E-3 20-13 3
E 5
3.8e-02 Actions: Remove obstruction - front moved Comments:
4.4.1-2 l
1.3E-3 20-7 1
E 5
6.3E-3 l 20-13 3
E 5
3.8e-02 Actions: Remove Obstruction - Lift Rear Comments:
4.4.3 1.3E-3 20-7 1
E 5
1.3E-3 20-13 1
E 5
1.3e-02 Actions: Use Chain B to position Door Comments:
4.4.3-R I
1.3E-3 20-7 1
E 5
1.3E-3 T 20-13 1
E 5
1.3e-02 Actions: Use Chain B to position door Comments: Obstruction must be removed to position door.
4.4.4 1 1.3E-3 20-7 1
E 5
1.3E-3 l 20-13 1
l 5
1.3e-02 Actions: Use Chain A to move door to flange Comments:
4.4.4-R I
1.3E-3 20-7 1
E 5
1.3E-3 l 20-13 1
E 5
1.3e-02 Actions: Use Chain A to move door to flange Comments: Door must be positioned to move to flange.
4.4.5 1 1.3E-3 20-7 1
E 5
1.3E-3 1 20-13 1
E 5
1 1.3e-02 Actions: Swing 4 bolts equally spaced Comments:
4.4.5-R I
1.3E-3 20-7 1
E 5
1.3E-3 l 20-13 1T 1 E
5 1.3e-02 Actions: Swing 4 bolts egally spaced Comments: Door must be against flange to sng bolts in position 4.4.7 l
1.3E-3 20-7 1
E 5
1.3E-3 20-13 l 1
E l
5 1.3e-02 Actions: Tighten bolt enough for seal contact Comments:
4.4.7-R I
1.3E-3 1 20-7 1
E 5
1.3E-3 1 20-13 1
E 5
1.3e-02 Actions: Tighten Bots enough for seal contact Comments: Bolts must be postioned to tighten for seal.
IT I
I-I T
I I
i I
Tr_
Page 28 of 29
I Risk Assessment for Kewaunee Containment Hatch Issue Revision 4 Execution Recovery 89-OBCMTNTDR-HE Table 8: 89-OBCMTNTDR-HE EXECUTION RECOVERY No.
Cond. HEP Total for Critical Step No.
Recovery Step (CrActot)
HE(Rec).,:
ep___
Rc)Se 4.4.1 Remove obstruction - front moved 3.8e.02 5.9e-03 4.4.3-R Use Chain B to position door 1.3e-02 MD 1.5e-01 4.4.1-2 Remove Obstruction - Lift Rear 3.8e.02 1.9e.02 4.4.3-R Use Chain B to position door 1.3e-02 HD 5.1e-01 4.4.3 Use Chain B to position Door 1.3e.02 2.0e-03 4.4.4-R Use Chain A to move door to flange 1.3e-02 MD 1.5e-01 4.4.4 Use Chain A to move door to flange 1.3e"2
_____2.0e-03 4.4.5-R Swing 4 bolts eqally spaced 1.3e-02 MD 1.5e-01 4.4.5 Swing 4 bolts equally spaced 1.3e402 2.0e403 4.4.7-R Tighten Bolts enough for seal contact 1.3e-02 MD 1.5e-01 4.4.7 Tighten bolt enough for seal contact 1.3e-02 Total R
_1.3e402
-Total Unrecovered:.
1.3e-41 Total Recovered:
4.4e.02;--
Page 29 of 29