ML20249C554
| ML20249C554 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 06/25/1998 |
| From: | Ohanlon J VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| 98-186A, NUDOCS 9806300306 | |
| Download: ML20249C554 (20) | |
Text
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'4 Vin <asir Ei.i:cTair Asn Pa >wn:n C< >u nsv Rn1:u m n, Vuuasir 232<:
June 25, 1998 U.S. Nuclear Regulatory Commission Serial No.
98-186A Attention: Document Control Desk NL&OS/ETS R0 Washington, D.C. 20555 Docket Nos.
50-338/50-339 License Nos.
NPF-4/Nr)F-7 Gentlemen:
VIRGINIA ELECTRIC AND POWER COMPANY-NORTH ANNA POWER STATION UNITS 1 AND 2 TECHNICAL SPECIFICATION CHANGE EDG ALLOWED OUTAGE TIME REQUEST FOR ADDITIONAL INFORMATION Virginia Electric and Power Company previously requested amendments, in the form of changes to the Technical Specifications, to Facility Operating License Numbers NPF-4 and NPF-7 for North Anna Power Station Units 1 and 2, respectively. The proposed changes would establish a fourteen-day allowed outage time -(AOT) for each emergency diesel generator. In a telephone conference call on June 2,1998, the NRC j
Staff requested additional information regarding the North Anna Probabilistic Safety 1
Assessment (PSA), current EDG reliability, and procedural controls for planned entries into the extended AOT. The requested information is provided in the attachment to this
- letter, if you have any questions or require additional information concerning this matter, please contact us.
Very truly yours, PcWA h/
James P. O'Hanlon Senior Vice President-Nuclear Attachment I
Commitments made in this letter:
1.
Develop procedural controls to prohibit entry into the extended (14 day) AOT for the EDG if severe weather conditions are expected as described in the attachment to this letter.
9806300306 980625 i
PDR ADOCK 05000338 P
PDR l
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41 cc:
U.S. Nuclear Regulatory Commission Region II Atlanta Federal Center -
61 Forsyth Street, S.W.
Suite 23T85 Atlanta, Georgia 30303 '
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. Mr. M. J. Morgan NRC Senior Resident inspector North Anna Power Station i
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Attachment 4
I Virginia Electric and Power Company North Anna Units 1 and 2 l
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June 2,1998 Telephone Conference Call Request for Additional Information Question 1: What software was used for the Probabilist:c Safety Assessment? What software is in use for the Configuration Analyses?
i Answer:
In both cases, Virginia Power has used the NUPRA code as developed by the Scientech Company. Scientech was formerly known as NUS.
Question 2: What level of PSA quality is maintained?
Answer:
Routine PSA quality is ensured using the same processes established to comply with 10 CFR 50, Appendix B.
Our Nuclear Design Control Program (NDCP) is designed to maintain quality work processes and to ensure that the requirements of Appendix B are met. PSA calculations and evaluations are performed in accordance with the NDCP similar to other engineering work. (This information was also provided in Reference 1.)
Question 3: How were the Emergency Diesel Generator (EDG) Common Cause Failure (CCF) factors developed?
Answer:
The North Anna Power Station Individual Plant Examination EDG Common Cause Failure basic event modelis based upon the Stage 3 and 4 process outlined in NUREG/CR-4780. Essentially, industry experience and plant specific data are analyzed to create a failure database, with the industry events re.-interpreted (mapping down) to the target plant (North Anna). The results of the data analysis are then applied with the Basic Parameter Model of NUREG/CR-4780. The final North Anna IPE EDG CCF model includes 6 dual CCF basic events (e.g., EDGs 1H and 1J),4 triple CCF events (e.g., EDGs 1H,1J and 2H) and one quadruple CCF basic event (EDG's 1H,1J,2H and 2J).
The North Anna Power Station EDG CCF model has been conservatively simplified to include two dual CCF basic events (EDGs 1H and 1J, and EDGs 2H and 2J), and one CCF basic event subsuming the remaining four dual, four triple and one quadruple CCF basic events. The two dual CCF basic events maintain their original quantification from the IPE NUREG/CR-4780 approach. The final CCF conservatively combines the remaining CCF fault exposures through a simple summation of the fault probabilities.
The basic event names and point estimates follow:
1EGEDG-CC-ALL, 8.82E-4; 1EGEDG-CC-1H-1J, 2.66E-4 and 1EGEDG-l CC-2H-2J. 2.66E-4.
Question 4: Provide the Station Blackout sequences and cut sets. Identify the Human Error Probabilities for the SBO diesel and the 4kv-bus crosstie.
Answer:
The North Anna Station Blackout is modeled as a loss of offsite power with failure of the Unit 1 Emergency Diesel Generators (EDGs) and failure of the Alternate AC Diesel Generator (AAC DG), as shown in the T1A event tree (attached as Figure 1). The Human Error Probability (HEP) for recovering power to an emergency bus is modeled by the basic event HEP-00P6:3, "0-OP-6.3, Operation of 0-AAC-DG-0M SBO Diesel." The following important sequences in the T1 A event tree contain HEP-00P6:3, I
and in the 3-year average maintenance case, each contributes at least 1% CDF (e g., 3.50e-07/yr):
T1AP32 T1A2CH1EP1RCLERF 1.32E-06/yr T1AP50 T1 A1FW1EP1RCLERF 1.29E-06/yr T1AP28 T1 A2CH1EPLERF 6.19E-07/yr T1AP48 T1 A1FW1EPLERF 6.02E-07/yr T1AP69 T1A1RC1EP1RCLERF 4.22E-07/yr The top 15 cut sets for each sequence are attached as Tables 1-5, to illustrate sequences containing HEP-00P6:3 (point estimate = 7.88E-2).
None of the North Anna Station Blackout sequences contain any cut sets with other electrical crosstie HEP basic events, such as HEP-0AP10. The North Anna PSA model includes electrical cross-tie HEP basic events, but cut sets containing these HEP basic events have frequencies below 1.0E-10/yr, and are truncated.
Question 5: What is the SBO diesel reliability?
Answer:
Station Administrative Procedure VPAP-0808, Emergency Diesel Generator Reliability Program, specifies an SBO diesel target reliability of 95%, consistent with NUMARC 87-00. Actual performance to date has been without failure, so that the measured diesel reliability is currently l
100 %.
]
Question 6: Why do asymmetries exist in the electrical distribution sensitivities?
Answer:
The asymmetries reflect actual differences in bus badings and crossties for the various emergency buses.
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Question 7: Provide the descriptive statistics (sAewness and kurtosis) for the CDF uncertainty distributions.
Answer.
The Virginia Power CDF calculations are performed with the NUPRA code.
Its uncertainty analysis module provides limited descriptive statistics but these do not include either the skewness or the kurtosis. As the NRC staff requested this information in order to confirm that the proposed change did not significantly change the CDF uncertainty l
distribution, a qualitative data presentation was proposed to the staff and approved via telecon on June 17,1998.
NUPRA generates a CDF distribution via Monte Carlo calculations. Its summary output includes a percentile table, the distribution mean and standard deviation. Output tables for the current 72-hour AOT and the proposed 14-day AOT are provided in Tables 6 and 7. The tables were used to generate a CDF probability density function (PDF). In this case, because the CDF data extend over several decades, the logarithm (in Base 10) of the CDF has been evaluated.
The probability density function of the CDF's for the current 72-hour AOT and the proposed 14-day AOT are shown in Figure 2. The contours are dominated by a large positive skew. As expected, there is little difference between the two curves, and much of that difference may be attributed to the Monte Carlo process.
No uncertainty calculation was performed f'or the proposed 24-month interval between preventive maintenance inspections. The 24-month CDF calculation was performed with a NUPRA sensitivity calculation, rather than a full model quantification, and the data were not available for a full solution. However, due to the way in which the 24-month impact is modeled, its probability density function is expected to fall between the two curves shown in Figure 2.
Question 8: What is the sensitivity of the Core Damag; Frequency (CDF) and the Large Early Release Frequency (LERF) to the proposed TS changes?
l Answer:
Those numbers are provided in Table 8, which is reproduced from Reference 1.
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~ Question 9: What provisions exist to prevent AOT entry during severe weather?
Answer.
Currently Administrative Procedure, VPAP-2001, " Station Planning And Scheduling," requires that "If...the risk of loss of off-site power is significantly increased due to.. environmental activity, those systems used to mitigate a loss of off-site power...should be maintained or returned to an available status as soon as practical." This requirement precludes l
AOT entry during severe weather.
Ir. addition to the above controls for equipment maintenance and testing, additional procedural controls are being established to require:
l that the extended weather forecast is reviewed to verify that severe weather is not predicted during the planned allowed outage time, and l.
prohibit entry into the extended (14-day) AOT for the EDG if severe weather conditions are predicted onsite during the duration of the AOT.
l An Abnormal Procedure exists that provides protective and compensatory actions in case of severe weather predicted onsite. Severe weather is defined as follows:
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Tornado Warning in effect t
l Tornado Watch in effect or sustained winds onsite of greater than l
73 mph Hurricane force winds projected High Wind Warning in effect Severe thunder / electrical storms L__-__-__-______
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References:
- 1. Lotter from J. P. O'Hanlon (Virginia Power) to U. S. Nuclear Regulatory Commission Document Control Desk, Technical Specification Change EDG Allowed Outage-
-Time Request for Additional Information, Serial No.98-186, dated May 5,1998, i
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Table 1 TlAP32. MPG Cut Sets NUPRA 2.33 Licensed to VIRGINIA Page 1
FILE : T1AP32.MGP Feb 13 21:29:01 1998 Top event unavailability
= 1.315E-006 Basic Event Data file referenced
= N7BC303. BED Number of cut sets in equation
= 10 Longest cut set (# of events)
=9 Largest cutoff value used in AND steps 1.000E-010
=
1 1.3132E-006 XCOM-1FW-08 LERF-18 NON-REC-B10 NON-REC-B102 IE-T1 1EGEDG-CC-ALL 2
2.6231E-010 XCOM-1FW-08 LERF-18 NON-REC-B10 NON-REC-B102 IE-T1 1EEEDG-FS-1H 1EEEDG TM-EEEG1J HEP-00P6:3 HEP-1AP33:2 3
2.6231E-010 XCOM-1FW-08 LERF-18 NON-REC-B10 NON-REC-B102 IE-T1 1EEEDG-FS-1J IEEEDG-TM-EEEG1H HEP-00P6:3 HEP-1AP33:2 4
2.5647E-010 XCOM-1FW-08 LERF-18 NON-REC-B10 NON-REC-B102 IE-T1 1EGEDG-CC-1H-1J HEP-00P6:3 HEP-1AP33:2 5
2.4341E-010 XCOM-1FW-08 LERF-18 NON-REC-B10 NON-REC-B102 IE-T1 1EEEDG-FR-1J 1EEEDG-TM-EEEG1H HEP-00P6:3 HEP-1AP33:2 6
2.4341E-010 XCOM-IFW-08 LERF-18 NON-REC-B10 NON-REC-B102 IE-T1 1EEEDG-FR-1H 1EEEDG-TM-EEEG1J HEP-00P6:3 HEP-1AP33:2 7
1.9791E-010 XCOM-1FW-08 LERF-18 NON-REC-B10 NON-REC-B102 IE-T1 IEEEDG-FS-1H 1EEEDG-FS-1J HEP-00P6:3 HEP-1AP33:2 8
1.8365E-010 XCOM-1FW-08 LERF-18 NON-REC-B10 NON-REC-B102 IE-T1 1EEEDG-FR-1J 1EEEDG-FS-1H HEP-00P6:3 HEP-1AP33:2 9
1.8365E-010 XCOM-1FW-08 LERF-18 NON-REC-BIO NON-REC-B102 IE-T1 1EEEDG-FR-1H 1EEEDG-FS-1J HEP-00P6:3 HEP-1AP33s2 10 1.7043E-010 XCOM-1FW-08 LERF-18 NON-REC-B10 NON-REC-B102 IE-T1 1EEEDG-FR-1H 1EEEDG-FR-1J HEP-00P6:3 HEP-1AP33:2 l
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Table 2 TI AP50.MGP Cut Sets NJPRA 2.33' Licensed to VIRGINIA Page 1
FILE : T1AP50..MGP' Feb 13.21:29:08 1998 Top event unavailability
=:1.286E-006 Basic Event Data file referenced
= N7BC303. BED Number of cut sets in equaf' ion
= 168 Longest' cut set (# of events,
=9 Largest cutoff value used in ArfD steps 1.000E-010 1
4.3279E-007 LERF-04 NON-REC-8102 NON-REC-B02 1FWTRB-FS-1FWP2-IE-T1 1EGEDG-CC-ALL 2
~4.1674E-007 LERF-04 NON-REC-B102 NON-REC-B02 1P"dTRB-FR-12 HP2 -NON-REC-12
.IE-T1 L
.3
.8.0517E-000 LERF-04 NON-REC-B102 NON-REC-B02 IFWTRB-TM-1FWP2-IE-T1 1EGEDG-CC-ALL 4
4.2295E-008 LERF-04 NON-REC-B102 NON-REC-B02 1MSAOV-CC-111AB IE-T1 1EGEDG-CC-ALL 5
1.7501E-008 LERF-04 NON-REC-B102 NON-REC-B02 IFWHEP-1FW543 IE-T1-1EGEDG-CC-ALL-6 1.4795E-008 LERF-04 NON REC-B102 NON-REC-B02 IFWCKV-FC-1FW148 IE-T1 1EGEDG-CC-ALL 7
1.0480E-008
~LERF-04 NON-REC-B102 NON-REC-B02 j
1FWTRB-FS-1FWP2 IE-T1
'1EEEDG-FS-1H 1EEEDG-TM-EEEG1J HEP-00P6:3 p
8 1.0480E-008 LERF-04 NON-REC-B102 NON-REC-B02
{..
1FWTRB-FS-1FWP2 IE-T1 1EEEDG-FS-1J 1EEEDG-TM-EEEG1H HEP-00P6:3 9
1.0247E-008 LERF-04 NON-REC-B102 NON-REC-B02 1FWTRB-FS-1FWP2 IE-T1-1EGEDG-CC-1H-1J HEP-00P6:3 10 1.0091E-008 LERF-04 NON-REC-B102 NON-REC-B02-1FWTRB-FR-12HP2 NON-REC-12 IE-T1 1EEEDG-FS-1H 1EEEDG-TM-EEEG1J HEP-00P6:3 11
.1.0091E-008 LERF-04 NON-REC-B102 NON-REC-B02 1FWTRB-FR-12HP2 NON-REC-12 IE-T1 IEEEDG-FS-1J IEEEDG TM-EEEG1H HEP-00P6:3 12 9.8667E-009 LERF-04 NON-REC-B102 NON-REC-B02 IFWTRB-FR-12HP2 NON-REC-12 IE-T1 1EGEDG-CC-1H-1J HEP-00P6:3 13 9.7252E-009 LERF-04 NON-REC-B102 NON-REC-B02 1FWTRB-FS-1FWP2 IE-T1 1EEEDG-FR-1J 1EEEDG-TM-EEEG1H HEP-00P6:3 14 9.7252E-009 LERF-04 NON-REC-B102 NON-REC-B02 IFWTRB-FS-1FWP2 IE-T1 1EEEDG-FR-1H 1EEEDG-TM-EEEG1J HEP-00P6:3 15 9.3646E-009 LERF-04 NON-REC-B102 ~
NON-REC-B02 IFWTRB-FR-12HP2 NON-REC-12 IE-T1
'1EEEDG-FR-1J 1EEEDG-TM-EEEG1H HEP-00P6:3 1
Table 3 TI AP28.MGP Cut Sets NUPRA 2.33 Licensed to VIRGINIA Page 1
FILE : T1AP28.MGP Feb 13 21:28:59 1998 Top event unavailability
= 6.188E-007 Basic Event Data file referenced
= N7BC303. BED Number of cut sets in equation
=6 Longest cut set (# of events)
=9 Largest cutoff value used in AND steps = 1.000E-010 1
6.1822E-007 XCOM-1RC-04 XCO" 1FW-08 NON-REC-B10 LERF-16 IE-T1 1EGEDG-CC-ALL 2
1.2349E-010 XCOM-1RC-04 XCOM-IFW-08 NON-REC-B10 LERF-16 IE-T1 1EEEDG-FS-1H 1EEEDG-TM-EEEG1J HEP-00P6:3 HEP-1AP33:2 3
1.2349E-010 XCOM-IRC-04 XCOM-1FW-08 NON-REC-B10 LERF-16 IE-T1 1EEEDG-FS-1J IEEEDG-TM-EEEG1H HEP-00P6:3 HEP-1AP33:2 4
1.2074E-010 XCOM-1RC-04 XCOM-1FW-08 NON-REC-B10 LERF-16 IE-T1 1EGEDG-CC-1H-1J HEP-OOP6:3 HEP-1AP33:2 5
1.1460E-010 XCOM-1RC-04 XCOM-1FW-08 NON-REC-B10 LERF-16 IE-T1 1EEEDG-FR-1J 1EEEDG-TM-EEEG1H HEP-00P6:3 HEP-1AP33:2 6
1.1460E-010 XCOM-1RC-04 XCOM-1FW-08 NON-REC-B10 LERF-16 IE-T1 1EEEDG-FR-1H 1EEEDG-TM-EEEG1J HEP-00P6:3 HEP-1AP33:2 l
t Table 4 TI AP48.MGP Cut Sets NUPRA,2.33 Licensed to VIRGINIA Page 1
FILE e T1AP48.MGP Feb 13 21:29:05 1998 Top event unavailability
= 6.023E-007 Basic Event Data file referenced
= N7BC303. BED Number of cut sets in equation 119
=
Longest cut set (# of events) 9
=
Largest cutoff value used in AND steps 1.000E-010
=
1 2.0375E-007 XCOM-1RC-04 LERF-03 NON-REC-B02 1FWTRB-FS-1FWP2 IE-T1 1EGEDG-CC-ALL 2
1.9619E-007 XCOM-1RC-04 LERF-03 NON-REC-B02 1FWTRB-FR-12HP2 NON-REC-12 IE-T1 1EGEDG-CC-ALL 3
3.7906E-008 XCOM-1RC-04 LERF-03 NON-REC-B02 1FWTRB-TM-1FWP2 IE-T1 1EGEDG-CC-ALL 4
1.9912E-008 XCOM-1RC-04 LERF-03 NON-REC-B02 1MSAOV-CC-111AB IE-T1 1EGEDG-CC-ALL 5
8.2394E-009 XCOM-1RC-04 LERF-03 NON-REC-B02 1FWHEP-1FW543 IE-T1 1EGEDG-CC-ALL 6
6.9652E-009 XCOM-1RC-04 LERF-03 NON-REC-B02 1FWCKV-FC-1FW148 IE-T1 1EGEDG-CC-ALL 7
4.9338E-009 XCOM-1RC-04 LERF-03 NON-REC-B02 IFWTRB-FS-1FWP2 IE-T1 1EEEDG-FS-1J 1EEEDG-TM-EEEG1H HEP-00P6:3 8
4.9338E-009 XCOM-1RC-04 LERF-03 NON-REC-B02 1FWTRB-FS-1FWP2 IE-T1 1EEEDG-FS-1H 1EEEDG-TM-EEEG1J HEP-00P6:3 9
4.8239E-009 XCOM-1RC-04 LERF-03 NON-REC-B02 1FWTRB-FS-1FWP2 IE-T1 1EGEDG-CC-1H-1J HEP-00P6:3 10 4.7509E-009 XCOM-1RC-04 LERF-03 NON-REC-B02 1FWTRB-FR-12HP2 NON-REC-12 IE-T1 1EEEDG-FS-1J 1EEEDG-TM-EEEG1H HEP-00P6:3 11 4.7509E-009 XCOM-1RC-04 LERF-03 NON-REC-B02 1FWTRB-FR-12HP2 NON-REC-12 IE-T1 1EEEDG-FS-1H 1EEEDG-TM-EEEG1J HEP-COP 6:3 12 4.6451E-009 XCOM-1RC-04 LERF-03 NON-REC-B02 1FWTRB-FR-12HP2 NON-REC-12 IE-T1 1EGEDG-CC-1H-1J HEP-00P6:3 j
13 4.5785E-009 XCOM-1RC-04 LERF-03 NON-REC-B02 1FWTRB-FS-1FWP2 IE-T1 1EEEDG-FR-1J IEEEDG-TM-EEEG1H HEP-00P6:3 14 4.5785E-009 XCOM-1RC-04 LERF-03 NON-REC-B02 IFWTRB-FS-1FWP2 IE-T1 1EEEDG-FR-1H IEEEDG-TM-EEEG1J HEP-00P6:3 15 4.4087E-009 XCOM-1RC-04 LERF-03 NON-REC-B02 1FWTRB-FR-12HP2 NON-REC-12 IE-T1 1EEEDG-FR-1H 1EEEDG-TM-EEEG1J HEP-00P6:3 i
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l Table $
TI AP69.MGP Cut Sets NUPRA 2.33 Licensed to VIRGINIA Page 1
I FILE T1AP69.MGP.
Feb 13 21:29:18 1998 j
l Top event unavailability
= 4.223E-007 Basic Event Data file referenced
= N7BC303. BED l
Number of cut sets in equation
= 66 Longest cut set (# of events)
=9 Largest cutoff value used in AND steps = 1.000E-010 i
{
1 1.6472E-007 NON-REC-B102 LERF-15 NON-REC-B01 1RCPORV-DMDSBO 1RCRV--FO-1456 IE-T1 1EGEDG-CC-ALL 2
1.6472E-007 NON-REC-B102 LERF-15 NON-REC-B01 1RCPORV-DMDSBO 1RCRV--FO-1455C IE-T1 1EGEDG-CC-ALL 3
3.9887E-009 NON-REC-B102 LERF-15 NON-REC-B01 1RCPORV-DMDSBO 1RCRV--FO-1456 IE-T1 1EEEDG-FS-1H 1EEEDG-TM-EEEG1J HEP-00P6:3 4
3.9887E-009 NON-REC-B102 LERF-15 NON-REC-B01 1RCPORV-DMDSBO 1RCRV--FO-1455C IE-T1 1EEEDG-FS-1J 1EEEDG-TM-EEEG1H HEP-00P6:3 5
3.9887E-009 NON-REC-B102 LERF-15 NON-REC-B01
'1RCPORV-DMDSBO 1RCRV--FO-1456 IE-T1 1EEEDG-FS-1J 1EEEDG-TM-EEEG1H HEP-00P6:3 6
3.9887E-009 NON-REC-B102 LERF-15 NON-REC-B01 1RCPORV-DMDSBO 1RCRV--FO-1455C IE-T1 1EEEDG-FS-1H 1EEEDG-TM-EEEG1J HEP-00P6:3 7
3.8999E-009 NON-REC-B102 LERF-15 NON-REC-B01 1RCPORV-DMDSBO 1RCRV--FO-1456 IE-T1 1EGEDG-CC-1H-1J HEP-00P6:3 8
3.8999E-009 NON-REC-B102 LERF-15 NON-REC-B01 1RCPORV-DMDSBO 1RCRV--FO-1455C IE-T1 1EGEDG-CC-1H-1J HEP-00P6:3 9
3.7014E-009 NON-REC-B102 LERF-15 NON-REC-B01
.1RCPORV-DMDSBO 1RCRV--FO-1456 IE-T1 1EEEDG-FR-1J 1EEEDG-TM-EEEG1H HEP-00P6:3 10 3.7014E-009 NON-REC-B102 LERF-15 NON-REC-B01 1RCPORV-DMDSBO 1RCRV--FO-1455C IE-T1 1EEEDG-FR-1J 1EEEDG-TM-EEEG1H HEP-00P6:3 11 3.7014E-009 NON-REC-B102 LERF-15 NON-REC-B01 1RCPORV-DMDSBO 1RCRV--FO-1455C IE-T1 1EEEDG-FR-1H 1EEEDG-TM-EEEG1J HEP-00P6:3 12 3.7014E-009 NON-REC-B102 LERF-15 NON-REC-B01 1RCPORV-DMDSBO 1RCRV--FO-1456 IE-T1 1EEEDG-FR-1H IEEEDG-TM-EEEG1J HEP-00P6:3 13 3.0095E-009 NON-REC-B102 LERF-15 NON-REC-B01 1RCPORV-DMDSBO 1RCRV--FO-1456 IE-T1 1EEEDG-FS-1H 1EEEDG-FS-1J HEP-00P6:3 14 3.0095E-009 NON-REC-B102 LERF-15 NON-REC-B01 1RCPORV-DMDSBO 1RCRV--FO-1455C IE-T1 1EEEDG-FS-1H 1EEEDG-FS-1J HEP-00P6:3 15 2.7927E-009 NON-REC-B102 LERF-15 NON-REC-B01 I-1RCPORV-DMDSBO 1RCRV--FO-1456 IE-T1 1EEEDG-FR-1H IEEEDG-FS-1J HEP-00P6:3 i
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Table 6 Uncertainty Analysis output 72-hour EDG AOT NUPRA 2.33 Property of VIRGINIA Uncertainty Analysis Results of equation file :N7B_B01 Performed 11:08 19 JUN 1998 Equation File
- N7BC303 Basic File N7BC303 Parameter File N7B_B01 Print File N7B,B01 Number of simulatior histories 15000
=
Run time 119.79 sec.
=
Top event mean unavailability 2.886E-04
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Distribution variance (2nd moment) 4.872E-05
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Distribution standard deviation 6.980E-03
=
Confidence Unavailability 99.5 4.721E-03 99.0 1.741E-03 97.5 4.355E-04 95.0 1.858E-04 90.0 9.250E-05 80.0 5.373E-05 75.0 4.583E-05 70.0 4.018E-05 60.0 3.311E-05 50.0 2.801E-05 40.0 2.396E-05 30.0 2.060E-05 25.0 1.903E-05 20.0 1.748E-05 10.0 1.418E-05 5.0 1.201E-05 2.5 1.052E-05 1.0 8.998E-06 0.5 8.140E-06 l
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a Table 7 Uncertainty Analysis output 14-day EDG AOT NUPRA 2.33 Property of VIRGINIA Uncertainty Analysis Results of equation file :N7B_B02 Performed :
11:12 19 JUN 1998 Equation File N7BC303 Basic File N7BC303 Parameter File N7B_201 Print File N7B_B02 Number of simulation histories 15000
=
Run time 138.08 sec.
=
Top event mean unavailability 2.717E-04
=
Distribution variance (2nd moment) 1.013E-04
=
Distribution standard deviation 1.006E-02
=
Confidence Unavailability 99.5 4.258E-03 99.0 1.691E-03 97.5 4.493E-04 95.0 1.836E-04 90.0 9.323E-05 80.0 5.490E-05 75.0 4.661E-05 70.0 4.128E-05 60.0 3.363E-05 50.0 2.857E-05 40.0 2.466E-05 30.0 2.116E-05 25.0 1.955E-05 20.0 1.792E-05 10.0 1,451E-05 5.0 1.235E-05 2.5 1.072E-05 1.0 9.112E-06 0.5 8.218E-06 i
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