ML080650403
| ML080650403 | |
| Person / Time | |
|---|---|
| Site: | Harris  |
| Issue date: | 03/10/2008 |
| From: | Vaaler M NRC/NRR/ADRO/DORL/LPLII-2 |
| To: | Donahue J Progress Energy Carolinas |
| Shared Package | |
| ML080650382 | List: |
| References | |
| TAC MC5630 | |
| Download: ML080650403 (128) | |
Text
March 10, 2008 Joseph W. Donahue, Vice President Nuclear Engineering & Services Progress Energy Post Office Box 1551 Raleigh, North Carolina 27602-1551
SUBJECT:
SHEARON HARRIS NUCLEAR POWER PLANT, UNIT 1 - PRELIMINARY RESULTS OF THE NRC STAFF REVIEW OF THE FIRE PROBABILISTIC RISK ASSESSMENT MODEL TO SUPPORT IMPLEMENTATION OF NATIONAL FIRE PROTECTION ASSOCIATION STANDARD NFPA-805, PERFORMANCE-BASED STANDARD FOR FIRE PROTECTION FOR LIGHT WATER REACTOR ELECTRIC GENERATING PLANTS (TAC NO. MC5630)
Dear Mr. Donahue:
This letter is to provide Progress Energy (PE) with a high-level summary and preliminary detailed observations resulting from the U.S. Nuclear Regulatory Commissions (NRCs) review of the Shearon Harris Nuclear Power Plant, Unit 1 (HNP) fire probabilistic risk assessment (PRA) model. The high-level summary and preliminary detailed observations are provided in the enclosure. A final detailed report is in preparation and will be available in the near future in the Agencywide Documents Access and Management System (ADAMS) at Accession No. ML080650420.
The NRC conducted this review because HNP is a National Fire Protection Association (NFPA) standard NFPA-805 pilot plant application, and the results of this pre-application audit will support the staffs review of HNPs anticipated license amendment request to transition the HNP fire protection program to one based on NFPA-805. Licensees that intend to transition to NFPA-805, other than the pilot plants, should plan to subject their fire PRA to an industry peer review as described in Regulatory Guide 1.205, Risk-Informed, Performance-Based Fire Protection for Existing Light-Water Nuclear Power Plants.
NRC staff and contractors conducted a review of the HNP fire PRA model in the first quarter of calendar year 2008. The onsite portion of the review took place the week of February 4, 2008, at the PE corporate offices in Raleigh, North Carolina. As stated in an NRC January 9, 2008, letter (ADAMS Accession No. ML080070531), the purpose of the review was to allow the NRC staff to assess the technical adequacy of the base HNP fire PRA model. Although not a peer review, the NRC staff review was conducted in accordance with the peer review guidelines in the PRA Standard to the extent practicable.
The American Society of Mechanical Engineers (ASME) combined PRA Standard, ASME/ANS RA-S-2007, Standard for Level 1/Large Early Release Frequency Probabilistic Risk Assessment for Nuclear Power Plant Application, (draft) (PRA Standard) includes a number of technical requirements for assessing the technical adequacy of a fire PRA. A peer review of a fire PRA model, as defined in the PRA Standard, evaluates that model against the applicable requirements. The scope of the review also includes the results of the peer review of the internal events PRA that formed the basis for building the fire PRA, as well as the requirements for configuration control and updates to the fire PRA model.
J. Donahue The NRC review team noted that the Harris fire PRA is not yet complete, some tasks have yet to be started, and many areas are still in draft form. At the time of the onsite portion of the review, the Harris fire PRA was more similar to a scoping analysis, rather than a completed fire PRA. The results produced by the fire PRA reviewed by the NRC staff were based upon a number of modeling conservatisms. The staff understands that further work is being done by PE to finalize the fire PRA and to reduce the excess conservatisms.
Because the fire PRA model available was a work-in-progress, the NRC staff review of the Harris baseline fire PRA cannot be regarded as sufficient for determination of technical adequacy to support risk-informed applications. Additional review of the completed fire PRA will be necessary in the future. One approach would be a full-scope industry peer review of the completed HNP fire PRA model.
If you have any questions regarding this matter, please contact me at (301) 415-3178.
Sincerely,
/RA/
Marlayna Vaaler, Project Manager Plant Licensing Branch II-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-400
Enclosure:
As stated cc w/enclosure: See next page
(Letter) ML080650403 (Pkg) ML080650382 NRR-106 OFFICE NRR/ADRO/DORL/LP NRR/ADES/DRA NRR/ADRO/DORL/LP NAME MVaaler SLaur TBoyce DATE 03/06/08 03/05/08 03/10/08 OFFICE NRR/ADES/DRA/AFPB NRR/ADES/DRA NRR/ADES/DRA NAME PLain AKlein MCunningham DATE 03/06/08 03/07/08 03/10/08
Mr. Joseph Donahue Shearon Harris Nuclear Power Plant, Progress Energy Unit No. 1 cc:
Mr. Robert J. Duncan II, Vice President Shearon Harris Nuclear Power Plant Carolina Power & Light Company Post Office Box 165, Mail Code: Zone 1 New Hill, North Carolina 27562-0165 Mr. Kelvin Henderson Plant General Manager Shearon Harris Nuclear Power Plant Progress Energy Carolinas, Inc.
P. O. Box 165, Mail Zone 3 New Hill, North Carolina 27562-0165 Mr. Chris L. Burton Director of Site Operations Shearon Harris Nuclear Power Plant Progress Energy Carolinas, Inc.
Post Office Box 165, Mail Zone 1 New Hill, North Carolina 27562-0165 Mr. David H. Corlett, Supervisor Licensing/Regulatory Programs Shearon Harris Nuclear Power Plant Progress Energy Carolinas, Inc.
P. O. Box 165, Mail Zone 1 New Hill, NC 27562-0165 Mr. Thomas J. Natale, Manager Support Services Shearon Harris Nuclear Power Plant Progress Energy Carolinas, Inc.
P. O. Box 165, Mail Zone 1 New Hill, North Carolina 27562-0165 Resident Inspector / Harris NPS c/o U. S. Nuclear Regulatory Commission 5421 Shearon Harris Road New Hill, North Carolina 27562-9998 Mr. J. Paul Fulford Manager, Performance Evaluation and Regulatory Affairs PEB 5 Progress Energy Carolinas, Inc.
Post Office Box 1551 Raleigh, North Carolina 27602-1551 Mr. John H. ONeill, Jr.
Pillsbury Winthrop Shaw Pittman, LLP 2300 N Street NW.
Washington, DC 20037-1128 David T. Conley Associate General Counsel II -
Legal Department Progress Energy Service Company, LLC Post Office Box 1551 Raleigh, North Carolina 27602-1551 Chairman of the North Carolina Utilities Commission Post Office Box 29510 Raleigh, North Carolina 27626-0510 Public Service Commission State of South Carolina Post Office Drawer 11649 Columbia, South Carolina 29211 Ms. Beverly Hall, Section Chief Division of Radiation Protection N.C. Department of Environment and Natural Resources 3825 Barrett Drive Raleigh, North Carolina 27609-7221 Mr. Robert P. Gruber Executive Director Public Staff NCUC 4326 Mail Service Center Raleigh, North Carolina 27699-4326 Ms. Margaret A. Force Assistant Attorney General State of North Carolina Post Office Box 629 Raleigh, North Carolina 27602 Mr. Tony Gurley, Chair Board of County Commissioners of Wake County P. O. Box 550 Raleigh, North Carolina 27602 Mr. Carl Thompson, Chair Board of County Commissioners of Chatham County P. O. Box 87 Pittsboro, North Carolina 27312
ENCLOSURE SHEARON HARRIS NUCLEAR POWER PLANT, UNIT 1 PRELIMINARY RESULTS OF THE NRC STAFF REVIEW OF THE FIRE PROBABILISTIC RISK ASSESSMENT MODEL TO SUPPORT IMPLEMENTATION OF NATIONAL FIRE PROTECTION ASSOCIATION (NFPA) STANDARD NFPA-805, PERFORMANCE-BASED STANDARD FOR FIRE PROTECTION FOR LIGHT WATER REACTOR ELECTRIC GENERATING PLANTS, AS ALLOWED UNDER TITLE 10 OF THE CODE OF FEDERAL REGULATIONS, PARAGRAPH 50.48(c)
DOCKET NO. 50-400 I.
BACKGROUND Nuclear Regulatory Commission (NRC) staff and contractors conducted a review of the Shearon Harris Nuclear Plant (HNP) Fire Probabilistic Risk Assessment (PRA) model in the first quarter of calendar year 2008. The onsite portion of the review took place the week of February 4, 2008, at the Progress Energy (PE) corporate offices in Raleigh, North Carolina.
The purpose, methodology, and other aspects of the review may be found in the NRC letter to PE dated January 9, 2008 (ADAMS Accession No. ML080070531).
As stated in that letter, the purpose of the review was to allow the NRC staff to assess the technical adequacy of the base HNP fire PRA model. The results of this review will support the staffs review of HNPs license amendment request to transition the HNP fire protection program to one based on the National Fire Protection Association (NFPA) standard NFPA-805, as allowed under Title 10 of the Code of Federal Regulations, Part 50, Section 48(c). The NRC conducted this review because HNP is a NFPA-805 pilot application.
The American Society of Mechanical Engineers (ASME) combined PRA Standard, ASME/ANS RA-S-2007, Standard for Level 1/Large Early Release Frequency Probabilistic Risk Assessment for Nuclear Power Plant Application, (draft) (PRA Standard) includes a number of technical requirements for assessing the technical adequacy of a fire PRA. There are thirteen technical elements, each addressing an area or task involved in constructing and using a fire PRA. The technical elements are composed of one or more high level requirements (HLRs).
The HLRs are further broken down into one or more supporting requirements (SRs). A peer review of a fire PRA model, as defined in the PRA Standard, evaluates that model against the applicable SRs and the HLRs. In addition to the thirteen elements, the peer review process requires the team to review the results of the peer review of the internal events PRA that formed the basis for building the fire PRA. Finally, the PRA Standard includes requirements for configuration control and updates to the fire PRA model, and a peer review includes an assessment of those requirements.
The NRC staff review of the Harris fire PRA model was a pre-application audit of the technical adequacy of the base fire PRA that will be used to support a license amendment request to transition the plants fire protection program to one based on NFPA-805, as stated above.
Although not a peer review, the NRC staff review was conducted in accordance with the peer review guidelines in the PRA Standard to the extent practicable.
A report is in preparation to document the staffs review of the HNP FPRA in a manner consistent with the requirements in the PRA Standard. The report will include not only the findings resulting from the NRC staff review of the fire PRA, but also information regarding review team members and qualifications. Paragraph V of the January 9, 2008, letter describes the content of the report that is being prepared.
This document provides the preliminary technical findings from the NRC staff review. It is being made available in advance of the final report so that interested stakeholders and PE are afforded a timely accounting of the results of the review. While there may be changes to some of the technical findings between issuance of this report and the final version, these are expected to be minor and should not impact the ability of PE to begin addressing the findings or of the public to be informed of their general nature.
II.
SUMMARY
OF FIRE PRA STAFF REVIEW High-Level Results of the NRC Staff Review of the Harris Fire PRA Model The NRC review team noted that the Harris fire PRA is not yet complete - some tasks have yet to be started, and many areas are still in draft form. At the time of the onsite portion of the review, the Harris fire PRA appeared to represent a scoping analysis, rather than a completed fire PRA. Very little detailed fire modeling has been done, the screening approach to identify which areas could generate a hot gas layer appears extremely conservative, and the probability of spurious actuation in the model reviewed was assumed to be 1.0. This is significant since there were a large number of spurious actuations included in the model. The results produced by the fire PRA reviewed by the NRC staff were based upon many conservatisms that will have to be addressed in the final fire PRA model.
Further work is being done by the licensee to finalize the fire PRA and to reduce the excess conservatisms. For example, detailed circuit analyses are being conducted so that more realistic probabilities of spurious actuation can be assigned. However, it appeared to the NRC review team that a large amount of work is still required to achieve a usable fire PRA model.
For these reasons, the NRC staff review of the Harris baseline fire PRA cannot be regarded as sufficient for determination of technical adequacy to support risk-informed applications.
Additional review of the completed HNP fire PRA will be necessary in the future. One approach would be a full-scope industry peer review of the completed fire PRA model.
Scope of Review There are 187 SRs in the fire portion of the PRA Standard if the model configuration control and update requirements are included. The NRC staff reviewed 139 SRs applicable to the Harris fire PRA model. An additional 18 SRs could not be reviewed because PE had not yet completed those tasks. These include the elements seismic fire and uncertainty and sensitivity analysis, as well as two HLRs in the fire scenario selection and analysis element. 30 SRs were not applicable for the Harris fire PRA model; for example, PE did not use qualitative or quantitative screening in developing the model, so the associated SRs do not apply.
The scope of this review included both estimation of core damage frequency (CDF) and large early release frequency (LERF) resulting from internal fire events. However, PE had not yet completed a LERF analysis, which accounts for some of the NRC review team findings.
General Findings and Results There were a number of findings and suggestions1 as a result of the NRC staff review of the Harris fire PRA model. The detailed facts and observations (F&Os) are in the next section. The findings included the following:
Use of non-rated barriers for fire compartments Containment bypass not considered in selection of equipment Incorrect instruments identified in some cases Power supply cables not cascaded into fire PRA model Coordination studies not tied well to configuration management Excessive modeling conservatisms leading to unrealistic results Zone of Influence not applied for wall and corner transient fire sources Only target considered was cables Fire response operator actions not modeled (neither beneficial nor adverse effects)
Errors of commission based on instrument availability not modeled Quantification method does not identify individual sequences to support identification of significant accident sequences Inability to determine significant components Guidance for configuration control references out-of-date material Documentation not complete in a number of areas Several areas not performed; e.g., LERF analysis, uncertainty analysis, seismic-fire interaction, assessment of potential fire effect on exposed structural steel Almost two-thirds of the HLRs had one or more SR that was not met. While HLRs are not assigned a capability category as are the SRs, all applicable SRs must be met at some level in order to conclude that the HLR has been satisfied. As shown in the first table below, over ten percent of the applicable HLRs were in areas that could not be reviewed because the Harris fire PRA model was not complete at the time of the NRC staff review.
The second table shows that almost two-thirds of the applicable SRs were met. About 13 percent of the SRs that were not met were in areas of the model that were mostly complete; the remaining 21 percent were in areas that were in-progress or not yet finished. However, several 1 Findings and Suggestions are discussed in NEI-07-12, Fire Probabilistic Risk Assessment (FPRA) Peer Review Process Guidelines, Draft Version F (ADAMS Accession No. ML073551166) caveats are associated with the SRs that are shown as met. First, because the Harris fire PRA is still a work-in-progress, major changes to the modeling and the resulting risk estimates are to be expected. Some of the changes to the model may be significant, resulting in the need for additional or follow-on review for technical adequacy. The second caveat is that the assigned capability category, even if the model had been complete at the time of the NRC staff review, applies to the base Harris fire PRA model. PE will need to determine what capability category is necessary to support a given risk-informed application, such as transition to NFPA-805.
High Level Requirements Overview:
HLRs with "Not Met" SRs 24 55%
HLRs not Ready for Review 5
11%
HLRs with all SRs "Met" 15 34%
Total Applicable HLRs:
44 100%
Supporting Requirements Overview SRs Not Met - Model in Development 15 10%
SRs Not Met - Model Appears Ready 21 13%
SRs Not Reviewed - Task not Performed 18 11%
SRs Appeared to be Met 103 66%
Total:
157 100%
III.
PRELIMINARY DETAILED FINDINGS OF THE NRC STAFF REVIEW This section presents the detailed findings of the NRC staff review team, organized by PRA Standard technical element. Summary tables showing a breakdown of HLRs, SRs, and numbers of F&Os are presented first. The review of the internal events PRA quality is documented next, followed by the thirteen technical elements in the same order as presented in the PRA Standard, section 3-1.7. The final section contains the results of the assessment of the PRA configuration control/model update area.
A typical section2 that follows has an up-front introduction, followed by a summary of the review teams conclusions regarding each HLR for that element. A second table provides the individual assessment of each SR that supports that HLR. Finally, the fact and observation (F&O) forms associated with that technical element are provided for each finding and suggestion generated by the review team.
2 Not all sections have all the information mentioned, because some elements were not applicable or could not be reviewed because they had not been done. The internal events PRA review has no HLRs or SRs.
As shown in the following table, the NRC review team identified 43 findings and 22 suggestions, for a total of 65 F&Os.
Shearon Harris Fire PRA - Number of F&Os by Element F&O Type Element Finding Suggestion Internal Events Peer Review 0
2 PP Plant Partitioning 3
0 ES Equipment Selection 4
1 CS Cable Selection and Location 5
0 QLS Qualitative Screening NA PRM FPRA Plant Response Model 3
2 FSS Fire Scenario Selection and Analysis 9
4 IGN Ignition Frequency 1
3 QNS Quantitative Screening NA CF Circuit Failures 1
2 HRA Human Reliability Analysis 6
6 SF Seismic Fire 1
0 FQ Fire Risk Quantification 8
0 UNC Uncertainty and Sensitivity Analysis 1
0 MUD PRA Configuration Control 1
2 Total:
43 22 The table below shows the number of supporting requirements that were not met in each HLR. An HLR is designated by the element abbreviation followed by a letter; for example, PP-A.
Shearon Harris Fire PRA High Level Requirements Summary Number of Supporting Requirements "Not Met" Element A
B C
D E
F G
H Internal Events Peer Review PP Plant Partitioning 0
2 1
ES Equipment Selection 1
1 1
1 CS Cable Selection and Location 4
0 1
QLS Qualitative Screening NA PRM FPRA Plant Response Model 2
3 NA 0
FSS Fire Scenario Selection and Analysis 1
1 1
1 1
Not Rev.
Not Rev.
2 IGN Ignition Frequency 0
0 QNS Quantitative Screening NA CF Circuit Failures 0
1 HRA Human Reliability Analysis 0
2 1
NA 0
SF Seismic Fire Not Rev.
Not Rev.
FQ Fire Risk Quantification 1
0 0
1 1
2 UNC Uncertainty and Sensitivity Analysis Not Rev.
MUD PRA Configuration Control 0
3 0
0 0
0 Sum:
9 13 5
3 2
2 0
2 The following table shows the number of SRs in each element that met a given capability category. It includes the number of SRs that did not meet any capability category, and includes columns for not reviewed and not applicable. The not reviewed designation is applied to SRs that should have been met but, owing to the fire PRA model not being completed, could not be evaluated by the NRC review team.
Shearon Harris Fire PRA Supporting Requirements Summary Element Not Met Met 1
1&2 2
2&3 3
Not Rev NA Internal Events Peer Review PP Plant Partitioning 3
7 2
ES Equipment Selection 4
6 3
2 CS Cable Selection and Location 5
7 1
1 2
QLS Qualitative Screening 7
PRM FPRA Plant Response Model 5
10 7
FSS Fire Scenario Selection and Analysis 7
18 6
1 1
3 4
9 1
IGN Ignition Frequency 8
1 1
1 4
QNS Quantitative Screening 6
CF Circuit Failures 1
2 HRA Human Reliability Analysis 3
4 1
SF Seismic Fire 6
FQ Fire Risk Quantification 5
5 UNC Uncertainty and Sensitivity Analysis 3
MUD PRA Configuration Control 3
11 Totals:
36 78 7
1 5
4 8
18 30
REVIEW INTERNAL EVENTS PRA QUALITY The combined PRA standard states that the review team should verify that the internal events PRA has been reviewed against the internal events elements, high-level requirements and supporting requirements, and that the fire PRA review team should review the outcome of that effort. It further states that results of the internal events PRA review shall be used in support of the determination of the capability category for supporting requirements in the fire PRA standard that reference requirements from the internal events section.
The peer review team reviewed the resolution of F&Os from the 2002 industry peer review of the Harris internal events PRA, the findings from the 2006 self-assessment to the ASME PRA standard, and the results of the 2007 focused-scope peer review of the PRA model. There were no findings. There were two F&O suggestions, IEPRA-1 and IEPRA-2, related to internal events supporting requirements in the accident sequence and thermal hydraulic elements.
SR Level Observation Basis Cap Cat IEPRA Suggestion AS-06: confirm that the assumption of no RHR pump damage for non-fire-induced SI events remains valid when fire is considered.
F&O IEPRA-1 N/A IEPRA Suggestion TH-01: confirm that the dismissal of SWGR room heatup as a concern remains valid when fire-induced failures of cooling equipment are considered.
F&O IEPRA-2 N/A
FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-06 ID Number: IEPRA-1 Level of Significance: Suggestion Reviewer: RHG Capability Category:
OBSERVATION:
AS-06: HFE for operators to secure RHR pumps following SI events with RCS at high pressure (protect pumps when running on minimum flow) was not modeled; Harris provided the basis for excluding this HFE, namely that pumps will successfully operate at minimum flow (does this assumption hold true for spurious SI events that would start the RHR pumps?) Suggestion F&O AS-01 is to confirm that the assumption of no RHR pump damage for non-fire-induced SI events remains valid when fire is considered.
BASIS FOR LEVEL OF SIGNIFICANCE:
Suggestion F&O IEPRA-AS-01 is to confirm that the assumption of no RHR pump damage for non-fire-induced SI events remains valid when fire is considered.
POSSIBLE RESOLUTION (REVIEWER):
Reference(s):
Personnel Contacted:
HNP-F/PSA-0069 (HNP - PSA WOG F&O Resolutions)
FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-06 ID Number: IEPRA-2 Level of Significance: Suggestion Reviewer: RHG Capability Category:
OBSERVATION:
TH-01: Room heatup for the SWGR rooms was dismissed based on the slow heatup rate and the low probability of the sequence of events necessary to lose SWGR room cooling; the latter justification (low probability) may not apply when fire-induced probabilities are considered; Suggestion F&O IEPRA-TH-01 is to confirm that the dismissal of SWGR room heatup as a concern remains valid when fire-induced failures of cooling equipment are considered.
BASIS FOR LEVEL OF SIGNIFICANCE:
Suggestion F&O IEPRA-TH-01 is to confirm that the dismissal of SWGR room heatup as a concern remains valid when fire-induced failures of cooling equipment are considered.
POSSIBLE RESOLUTION (REVIEWER):
Reference(s):
Personnel Contacted:
HNP-F/PSA-0069 (HNP - PSA WOG F&O Resolutions)
PLANT PARTITIONING ELEMENT This element defines the physical boundaries of the analysis (i.e., the locations within a plant where fire scenarios are postulated),
and divides the various volumes within that boundary into physical analysis units generally referred to as fire areas or fire compartments. Fire is a highly spatial phenomenon; hence, FPRA quantification and reporting is generally organized in accordance with the physical divisions (the physical analysis units) defined during plant partitioning.
HIGH LEVEL REQUIREMENTS FOR PLANT PARTITIONING (PP)
HLR HLR Description HLR Summary (From Review)
HLR-PP-A The FPRA shall define the global boundaries of the analysis so as to include all plant locations relevant to the plant-wide FPRA.
The Global Analysis Boundary requirements were met based on the inclusion of all buildings and equipment within the protected area as outlying areas (Cooling Tower Structure, Emergency Service Water Intake Structure, etc.) and justification of the excluded buildings/areas. There were no F&Os associated with this HLR.
HLR-PP-B The FPRA shall perform a Plant Partitioning analysis to identify and define the physical analysis units to be considered in the FPRA.
Use of the predefined fire areas as the basic Fire PRA physical analysis units is considered acceptable practice for all capability categories. However, the licensee has chosen to define smaller physical analysis units consistent with capability category 2&3 of supporting requirement PP-B1. Supporting requirement PP-B1 is not met because the licensee has not justified the use of non-rated barriers for these smaller physical analysis units. Supporting requirements PP-B2 through PP-B5, which would not be applicable had the licensee used the predefined fire areas, are considered applicable for the Harris plant. Refer to F&O findings PP-B2-1, PP-B2-2, and PP-C3-1.
HLR-PP-C The FPRA shall document the results of the Plant Partitioning analysis in a manner that facilitates FPRA applications, upgrades, and peer review.
The documentation for this element appeared adequate except in one case; refer to F&O finding PP-C3-1 involving justification for using non-rated barriers.
SUPPORTING REQUIREMENTS FOR PLANT PARTIONING SR Level Observation Basis Cap Cat PP-A1 Summary Global Analysis Boundary requirements are met based on the inclusion of all buildings and equipment within the protected area as outlying areas (Cooling Tower Structure, Emergency Service Water Intake Structure, etc.) and justification of the excluded buildings/areas.
Met PP-B1 Summary Although they have created fire compartments smaller than the fire areas in the current fire protection plan, they do not meet Capability Category 2&3 because PP-B2 has not been met.
(B2 not met for justification for use of non-rated barriers).
See PP-B2 Not Met PP-B2 Finding Justification for non-rated partition boundaries insufficient. Insufficient justification/
documentation for "rooms" within Fire Compartments.
F&O PP-B2-1 F&O PP-B2-2 Not Met PP-B3 Summary Spatial separation has only been used for exterior features/fire compartments.
N/A PP-B4 Summary Met. Fire Physical Analysis Units have not utilized Electrical Raceway Fire Barrier Systems as a defining barrier.
Met PP-B5 Summary Active fire protection features (that have not been considered as part of a qualified fire barrier) have not been used.
N/A PP-B6 Summary Met. The defined physical analysis units encompass all locations within the global analysis boundary and no two physical analysis units overlap.
Met PP-B7 Summary Met. There is ample evidence that confirmatory walkdowns were performed to verify conditions and characteristics of credited partitioning elements.
Met PP-C1 Summary Met.
Met PP-C2 Summary Met. Buildings excluded from global analysis boundary have adequate justification.
Met PP-C3 Finding Inadequate justification for non-rated barriers and the use of rooms to partition physical analysis units.
F&O PP-C3-1; Refer to PP-B2 Not Met PP-C4 Summary Although several different numbering/naming conventions are in use, there are adequate mapping tables provided to guide the appropriate use within the PRA.
Met
FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-05 ID Number: PP-B2-1 Level of Significance: Finding Reviewer: HXB Capability Category: Not Met OBSERVATION:
Not Met - Justification for non-rated partition boundaries insufficient; standard and 6850 requires a technical discussion regarding fire spread, subtstantially containing the affects of fire, etc.
BASIS FOR LEVEL OF SIGNIFICANCE:
Standard requires justification for the use of non-rated barriers. There were numerous instances of summary statements such as "Non-rated walls fully enclose the compartment and are adequate for defining compartment boundaries." Discussion 2 references NUREG-6850 for guidance on justifications. The NUREG provides guidance for addressing such items as Open Doorways, Unsealed Cable Penetrations, Gratings, Open Stairwells, etc. The NUREG also discussed using a 1-hour equivalent fire rating as acceptable to be "substantial enough to meet conditions defining a 1-hour rating can be credited in partitioning."
POSSIBLE RESOLUTION (REVIEWER):
Provide a technical justification for non-rated barrier acceptability. Include in the discussion the presence or absence of penetrations through the barrier, openings, and other features that would otherwise disqualify the barrier as a rated barrier.
Reference(s):
Personnel Contacted:
PI-FPIP-NGG-0201, Rev. 0 HNP-F/PSA-0071, Rev. 1 Dave Miskiewicz
FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-05 ID Number: PP-B2-2 Level of Significance: Finding Reviewer: HXB Capability Category: Not Met OBSERVATION:
Not Met - Insufficient justification/documentation for "rooms" within Fire Compartments.
Drawings provided in calculation do not provide sufficient information to indicate why hot gas layer could be formed in smaller areas than fire compartment.
BASIS FOR LEVEL OF SIGNIFICANCE:
Standard requires justification for the use of smaller physical analysis units. The fact that a section of a room may allow a hot gas layer to form does not necessarily meet the intent of "spacial separation" as treated in the standard.
POSSIBLE RESOLUTION (REVIEWER):
Remove the treatment of rooms from the plant partitioning section of the PRA and handle it within the scenario development in either Scoping or Detailed Fire Modeling tasks.
Reference(s):
Personnel Contacted:
PI-FPIP-NGG-0201, Rev. 0 HNP-F/PSA-0071, Rev. 1 Dave Miskiewicz
FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-05 ID Number: PP-C3-1 Level of Significance: Finding Reviewer: HXB Capability Category: Not Met OBSERVATION:
Not met. Addequate justification required for non-rated barriers and the use of rooms as partitioning physcial anlaysis units.
BASIS FOR LEVEL OF SIGNIFICANCE:
Refer to PP-B2 POSSIBLE RESOLUTION (REVIEWER):
Reference(s):
Personnel Contacted:
PI-FPIP-NGG-0201, Rev. 0 HNP-F/PSA-0071, Rev. 1 EQUIPMENT SELECTION ELEMENT This element identifies (and locates) the set of plant equipment that will be included in the FPRA. This includes: a) equipment that, if damaged as a result of a fire will lead to a plant trip (or other initiating event) either directly or as a result of operator action in response to a fire, b) equipment required to respond to each of the initiating events identified, and c) equipment whose spurious operation as a result of a fire will adversely affect the response of systems or functions required to respond to a fire. Equipment selection must occur in close coordination with the FPRA plant response model element because the plant response model defines the initiating events to be considered in the FPRA. Selected equipment is also mapped to the fire compartments defined in the PP element. This mapping information is needed to complete the Qualitative Screening (QLS) and Fire Scenario Selection and Analysis (FSS) elements.
HIGH LEVEL REQUIREMENTS FOR EQUIPMENT SELECTION (ES)
HLR HLR Description HLR Summary (From Review)
HLR-ES-A The FPRA shall identify equipment whose failure caused by an initiating fire including spurious operation will contribute to or otherwise cause an initiating event.
All supporting requirements for this HLR appeared to be met except ES-A6, which was not met because the licensee has not included LERF in the fire PRA scope.
The licensee procedure contains guidance on selection of equipment failures for initiating events provided that they are in the safe shutdown equipment list (SSEL) and the internal events PRA. An additional list of initiating events provided by the Westinghouse Owners Group is being reviewed to ensure all applicable initiating events have been considered. Interlocks and two spurious actuations were considered in the consideration of fire initiating events. Refer to F&O finding ES-A6-1 regarding lack of a LERF analysis.
HLR-ES-B The FPRA shall identify equipment whose failure including spurious operation would adversely affect the operability/functionality of that portion of the plant design to be credited in the FPRA.
All supporting requirements for this HLR appeared to be met except ES-B4, which was not met because the licensee has not addressed containment bypass other than ISLOCA. The licensee considered all internal events PRA and SSEL items, and considered the potential for two spurious operations. The licensee should finish the in-process assessment of potential additional initiating events (list derived from Westinghouse Owners Group) and provide guidance to the expert panel on how to consider these initiating events. The licensee is currently assessing an additional list derived from the WOG. Refer to F&O finding ES-B4-1 and suggestion ES-B3-1.
HLR-ES-C The FPRA shall identify instrumentation whose failure including spurious operation would impact the reliability of operator actions associated with that portion of the Supporting requirement ES-C1 was not met. In several cases, the reviewer noted that the incorrect instrument was identified. The licensee did identify instrumentation that could cause operators to take an incorrect action and identified instruments that operators would use to provide confirmation of an action (ES-C2).
HIGH LEVEL REQUIREMENTS FOR EQUIPMENT SELECTION (ES)
HLR HLR Description HLR Summary (From Review) plant design to be credited in the FPRA.
Supporting requirement ES-C2 appears to imply, in part, that errors of commission need to be considered; this aspect was not reviewed. Refer to F&O finding ES-C1-1 regarding incorrect instruments identified.
HLR-ES-D The FPRA shall document the FPRA equipment selection, including that information about the equipment necessary to support the other FPRA tasks (e.g., equipment identification; equipment type; normal, desired, failed states of equipment; etc.) in a manner that facilitates FPRA applications, upgrades, and peer review.
The documentation of the ES element is not sufficient to support peer review. Better traceability is needed, especially related compartments and scenarios. The standard requires that the cables need to be identified with the component (relative to its failure mode). There are no links to this information which makes tracing components difficult for future updates. Suggest creating a database with fields of components, cables which cause the failure state, mode of failure (spurious, short to ground, etc.), compartment location with FRANC scenario for all routings per cable, and basic event mapping. Documents reviewed included FPIP-202 Rev. 0, HNP-F/PSA-0076 Rev. 0, and HNP-FPSA-0077 Rev. 0. Refer to F&O finding ES-D1-1.
Equipment Selection SUPPORTING REQUIREMENTS FOR EQUIPMENT SELECTION SR Level Observation Basis Cap Cat ES-A1 Summary FPIP-202 does contain guidance on selection of equipment failures for initiating events provided that they are in the safe shutdown equipment list (SSEL) and the internal events PRA. In general, Harris handled initiating events by using a generic event of %FIRE with a frequency of 1.0 along with individual compartment events inside the internal events fault tree.
Met ES-A2 Summary Interlocks were considered when separate cases were investigated through the fire PRA database, control wiring diagrams and FRANC mapping.
Suggest linked roadmap to facilitate easier validation.
Met ES-A3 Summary FPIP-202 does contain guidance on selection of equipment failures for initiating events provided that they are in the safe shutdown equipment list (SSEL) and the internal events PRA. Evidence is seen in Attachment 1 of HNP-FPSA-0077 for previously screened potential initiators.
Met ES-A4 Summary Step 4 of HNP-FPSA-0077 provides guidance for two spurious actuations. The expert panel Engineering Change document EC54965, Rev. 0 provides two spurious actuation guidance in Attachment P.
3 ES-A5 Summary Initiating events are not treated separately from internal fire events in this model. The licensee mapped failures to the mitigating portion of the fault tree.
2 ES-A6 Finding Harris has not considered LERF at this point.
F&O ES-A6-1 Not Met ES-B1 Summary All internal events and FSSPMD are used as a starting point in HNP-FPSA-0077.
3 ES-B2 Summary HNP-FPSA-0077, step 7 specifies two spurious actuations.
2 ES-B3 Sug-gestion HNP-FPSA-0077, attachment 6 has a list of additional equipment which has to be added, it is derived from the existing FSSEL. The expert panel had considered initiating events outside the scope of the original SSEL and internal events PRA. The licensee is currently assessing an additional list derived from the WOG. However, there is no guidance for the expert panel on how to include these initiators for consideration.
F&O ES-B3-1 Met ES-B4 Finding Not met because containment bypass other than ISLOCA has not been addressed.
F&O ES-B4-1 Not Met ES-B5 Summary Tested cases of flow diversion from RWST and charging pump minimum flow valves misposition due to interlock failure. Found that mappings were present in the FRANC input.
Met SUPPORTING REQUIREMENTS FOR EQUIPMENT SELECTION SR Level Observation Basis Cap Cat ES-B6 Summary Licensee apparently included combinations which might be screened out on probability.
Met ES-C1 Finding Incorrect instrumentation was identified in several cases reviewed.
F&O ES-C1-1 Not Met ES-C2 Summary does identify instrumentation that could cause the operators to take an incorrect action, and also identifies the instrumentation that could be used as confirmation of the action. This is not restricted to consequences that are not already included and therefore is closer to a Capability Category II.
2 ES-C2 Other It is difficult to determine what is intended by this supporting requirement. It appears to be related to errors of commission.
ES-D1 Finding The documentation of the ES element is not sufficient to support peer review. Better traceability is needed, especially related compartments and scenarios.
F&O ES-D1-1 Not Met FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-05 ID Number: ES-A6-1 Level of Significance: Finding Reviewer: JAC Capability Category: Not Met OBSERVATION:
Harris has not considered LERF at this point.
BASIS FOR LEVEL OF SIGNIFICANCE:
POSSIBLE RESOLUTION (REVIEWER):
Reference(s):
Personnel Contacted:
FPIP-202 Rev. 0 HNP-F/PSA-0076 Rev. 0 HNP-FPSA-0077 Rev. 0 FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-05 ID Number: ES-B3-1 Level of Significance: Suggestion Reviewer: JAC Capability Category: Met OBSERVATION:
HNP-FPSA-0077, attachment 6 has a list of additional equipment which has to be added, it is derived from the existing FSSEL. The expert panel had considered initiating events outside the scope of the original SSEL and internal events PRA. The licensee is currently assessing an additional list derived from the WOG. However, there is no guidance for the expert panel on how to include these initiators for consideration. The licensee should finish the in-process assessment of potential additional initiating events (list derived from Westinghouse Owners Group) and provide guidance to the expert panel on how to consider these initiating events.
BASIS FOR LEVEL OF SIGNIFICANCE:
POSSIBLE RESOLUTION (REVIEWER):
Reference(s):
Personnel Contacted:
HNP-FPSA-0077 Rev. 0, Attachment 6 FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-06 ID Number: ES-B4-1 Level of Significance: Finding Reviewer: JAC Capability Category: Not Met OBSERVATION:
Not met because containment bypass other than ISLOCA has not been addressed.
HNP-FPSA-0077 considers two spurious actuations for ISLOCA. After discussion with licensee, expert panel might have considered more than two spurious actuations however, there is no documentation guidance on considering beyond two actuations.
BASIS FOR LEVEL OF SIGNIFICANCE:
POSSIBLE RESOLUTION (REVIEWER):
Reference(s):
Personnel Contacted:
FPIP-202 Rev. 0 HNP-F/PSA-0076 Rev. 0 HNP-FPSA-0077 Rev. 0 Dave Miskiewicz FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-05 ID Number: ES-C1-1 Level of Significance: Finding Reviewer: GWP Capability Category: Not Met OBSERVATION:
The table includes an identification of an indication that is used to provide information to the operators in their performance of a required action.
While the general assumption is that there is redundant or diverse indication to support actions, in some cases, only one instrument is identified. An example is OPER-1, where the indication seems to relate more to confirmation that an action has been performed (and therefore affects the recovery of a failed first attempt (i.e. internal to the calculation of the HEP)), rather than an indication that would initiate the action. Even if this were the appropriate instrument it would not answer the question of whether there is redundant and diverse instrumentation.
In the case of OPER-3, the instrument/equipment is Accumulator and Pressurizer PORV n2 supply manual valve. It would be expected that the instrumention would be low steam generator level.
Therefore, while some identification has been made, it would not appear to be complete.
BASIS FOR LEVEL OF SIGNIFICANCE:
POSSIBLE RESOLUTION (REVIEWER):
Reference(s):
Personnel Contacted: of HNP-F-PSA-0077 Ricardo Davis-Zapata FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-05 ID Number: ES-C1-1 Level of Significance: Finding Reviewer: GWP Capability Category: Not Met FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-06 ID Number: ES-D1-1 Level of Significance: Finding Reviewer: JAC Capability Category: Not Met OBSERVATION:
The documentation of the ES element is not sufficient to support peer review. Better traceability is needed, especially related compartments and scenarios. The standard requires that the cables need to be identified with the component (relative to its failure mode). There are no links to this information which makes tracing components difficult for future updates. Suggest creating a database with fields of components, cables which cause the failure state, mode of failure (spurious, short to ground, etc.), compartment location with FRANC scenario for all routings per cable, and basic event mapping. Documents reviewed included FPIP-202 Rev. 0, HNP-F/PSA-0076 Rev. 0, and HNP-FPSA-0077 Rev. 0.
BASIS FOR LEVEL OF SIGNIFICANCE:
POSSIBLE RESOLUTION (REVIEWER):
Reference(s):
Personnel Contacted:
CABLE SELECTION ELEMENT This element identifies (and locates) (a) cables that are required to support the operation of FPRA equipment selected (see element ES), and (b) cables whose failure could adversely affect credited systems and functions. This element includes an assessment of cable failure modes and effects including consideration of fire-induced spurious operations. Equipment failure mode information is used in the Plant Response Model (PRM) element to ensure that all potentially risk-relevant equipment failure modes are included in the plant response model (e.g., loss of function failures versus spurious operation). Selected cables are also mapped to the fire compartments defined in the PP element. This mapping information is needed to complete the Qualitative Screening (QLS) and Fire Scenario Selection and Analysis (FSS) elements.
HIGH LEVEL REQUIREMENTS FOR CABLE SELECTION AND LOCATION (CS)
HLR HLR Description HLR Summary (From Review)
HLR-CS-A The FPRA shall identify and locate the plant cables whose failure could adversely affect credited equipment or functions included in the FPRA plant response model, as determined by the Equipment Selection process (HLR-ES-A, HLR-ES-B, and HLR-ES-C).
Four supporting requirements for this HLR were not met. At least one instance was identified where postulated fire damage to a power supply cable was not reflected in the Fire PRA model. Inter-cable and three-phase hot shorts were considered for ISLOCA scenarios, but not for containment bypass. Refer to F&O findings F&O CS-A3-1, CS-A4-1, CS-A7-1, and CS-A8-1.
HLR-CS-B The FPRA shall (a) perform a review for additional circuits that are either required to support a credited circuit (i.e., per HLR-CS-A) or whose failure could adversely affect a credited circuit, and (b) identify any additional equipment and cables related to these additional circuits consistent with the other equipment and cable selection requirements of this Standard.
The sole supporting requirement for this HLR was met. The licensee procedure includes verification of proper electrical coordination with appropriate actions for any circuits not properly coordinated.
HLR-CS-C The FPRA shall document the cable selection and location process and results in a manner that facilitates FPRA applications, upgrades, and peer review.
The documentation requirements for the Cable Selection element were generally met, with the exception of one finding related to configuration management of electrical coordination calculations; refer to F&O finding CS-C4-1. (Supporting requirement CS-C3 was not applicable, because assumed cable routing was not used.)
Cable Selection and Location SUPPORTING REQUIREMENTS FOR CABLE SELECTION SR Level Observation Basis Cap Cat CS-A1 Summary Calculation HNP-F/PSA-0077, Rev. 0 documents the components included in the scope of the Fire PRA. The Fire PRA documentation demonstrates that the cables associated with Fire PRA components have been identified in the Fire PRA.
12 different Fire PRA components were reviewed for failure modes, cable inclusion and model inclusion. All were acceptable.
Met CS-A2 Summary Calculation HNP-F/PSA-0077, Rev. 0 provides documentation that up to two components and/or cables have been identified and considered within the scope of the Fire PRA.
Met CS-A3 Finding One instance was identified where postulated fire damage to a power supply cable was not reflected in the Fire PRA model.
F&O CS-A3-1 Not Met CS-A4 Finding One instance was identified where postulated fire damage to a power supply cable was not reflected in the Fire PRA model.
F&O CS-A4-1 Not Met CS-A5 Summary Calculation HNP-F/PSA-0077, Rev. 0 references the Post-Fire Safe Shutdown Analysis for the methodology to be used for circuit analysis, which specifically requires consideration of hot shorts, shorts to ground and open circuits as fire-induced damage states.
Met CS-A6 Summary Calculation HNP-F/PSA-0077, Rev. 0 references the Post-Fire Safe Shutdown Analysis for the methodology to be used for circuit analysis, which specifically requires consideration of hot shorts, shorts to ground and open circuits as fire-induced damage states. Calculation HNP-E-ELEC-0001, Rev. 1 specifically addresses Multiple High Impedance Faults as well as verification of proper overcurrent protection coordination.
Met CS-A7 Finding Inter-cable hot shorts not considered for containment bypass that could result in large early release.
F&O CS-A7-1 Not Met CS-A8 Finding Three-phase hot shorts not considered for containment bypass that could result in large early release.
F&O CS-A8-1 Not Met CS-A9 Summary Fire PRA and Safe Shutdown methodology both assume hot shorts of up to two cables and/or components.
Met CS-A10 Summary Cable routing methodology documented in HNP-E-ELEC-0001, Rev. 1 includes cross referencing cable routing to the Fire PRA physical analysis units, down to the cable raceway/conduit level for use in fire scenario development. The information 3
SUPPORTING REQUIREMENTS FOR CABLE SELECTION SR Level Observation Basis Cap Cat includes treatment of termination end locations.
The Fire PRA addressed the fire impact on end point locations through the implementation of "Self" fire scenario variations.
CS-A11 Other Assumed cable routing was not used at Harris.
N/A CS-B1 Summary Calculation HNP-E-ELEC-0001, Rev. 1 includes verification of proper electrical coordination with appropriate actions for any circuits that are not properly coordinated.
2&3 CS-C1 Summary Documentation of cable selection and location methodology is contained within the Post-Fire Safe Shutdown calculation and associated FSSPMD database.
Met CS-C2 Summary Documentation of cable selection and location methodology is contained within the Post-Fire Safe Shutdown calculation and associated FSSPMD database.
Met CS-C3 Other Assumed cable routing was not used at Harris.
N/A CS-C4 Finding No configuration management tie to the electrical coordination calculations performed.
F&O CS-C4-1 Not Met
FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-07 ID Number: CS-A3-1 Level of Significance: Finding Reviewer: HXB Capability Category: Not Met OBSERVATION:
Upon detailed investigation, at least one instance was identified where postulated fire damage to a power supply cable was not reflected in the Fire PRA model.
Specifically, the cable that provides power to MCC 1A24 from the 480V load center was not modeled such that fire damage to cable 1767B would not result in the failure of valve 1RC-113A (PORV Block Valve) due to loss of power.
BASIS FOR LEVEL OF SIGNIFICANCE:
Fire PRA Plant Response Model will not accurately reflect the loss of a power supply to an active component that has a requirement to actively close, which requires power (valve is a motor operated valve that requires power to change position to the required safe shutdown position).
POSSIBLE RESOLUTION (REVIEWER):
Revise Plant Response Model to include 480V load center, MCC and associated cables.
Reference(s):
Personnel Contacted:
FSSPMD FRANC model CAFTA model Fire PRA Database Dave Miskiewicz
FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-07 ID Number: CS-A4-1 Level of Significance: Finding Reviewer: HXB Capability Category: Not Met OBSERVATION:
Upon detailed investigation, at least one instance was identified where postulated fire damage to a power supply cable was not reflected in the Fire PRA model.
Specifically, the cable that provides power to MCC 1A24 from the 480V load center was not modeled such that fire damage to cable 1767B would not result in the failure of valve 1RC-113A (PORV Block Valve) due to loss of power.
BASIS FOR LEVEL OF SIGNIFICANCE:
Fire PRA Plant Response Model will not accurately reflect the loss of a power supply to an active component that has a requirement to actively close, which requires power (valve is a motor operated valve that requires power to change position to the required safe shutdown position).
POSSIBLE RESOLUTION (REVIEWER):
Revise Plant Response Model to include 480V load center, MCC and associated cables.
Reference(s):
Personnel Contacted:
FSSPMD FRANC model CAFTA model Fire PRA Database Dave Miskiewicz
FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-07 ID Number: CS-A7-1 Level of Significance: Finding Reviewer: HXB Capability Category: Not Met OBSERVATION:
Although inter-cable hot shorts have been considered for interfacing system LOCAs, the same can not be said for containment bypass that results in core damage and large early release.
BASIS FOR LEVEL OF SIGNIFICANCE:
POSSIBLE RESOLUTION (REVIEWER):
Reference(s):
Personnel Contacted:
HNP-F/PSA-0077, Rev. 0 HNP-E-ELEC-0001, Rev. 1
FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-07 ID Number: CS-A8-1 Level of Significance: Finding Reviewer: HXB Capability Category: Not Met OBSERVATION:
Although three-phase hot shorts were postulated as part of the safe shutdown analysis for interfacing system LOCAs, I found no evidence of a review of three-phase hot shorts that could result in containment bypass.
BASIS FOR LEVEL OF SIGNIFICANCE:
POSSIBLE RESOLUTION (REVIEWER):
Reference(s):
Personnel Contacted:
HNP-F/PSA-0077, Rev. 0 HNP-E-ELEC-0001, Rev. 1
FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-07 ID Number: CS-C4-1 Level of Significance: Finding Reviewer: HXB Capability Category: Not Met OBSERVATION:
Although Calculation HNP-E-ELEC-0001, Rev. 1 includes verification of proper electrical coordination with appropriate actions for any circuits that are not properly coordinated, there is no configuration management tie to the electrical coordination calculations performed.
BASIS FOR LEVEL OF SIGNIFICANCE:
Any future changes to the electrical coordination calculations must be reviewed for possible impact to the safe shutdown analysis and the resulting impact on the Fire PRA model.
POSSIBLE RESOLUTION (REVIEWER):
Include by reference any and all electrical coordination calculations reviewed as part of the Post-Fire Safe Shutdown Analysis.
Reference(s):
Personnel Contacted:
HNP-F/PSA-0077, Rev. 0 HNP-E-ELEC-0001, Rev. 1 Robert Rhodes QUALITATIVE SCREENING ELEMENT This element identifies fire compartments that can be assumed to have little or no risk significance without quantitative analysis.
(QLS only considers compartments as individual contributors. All compartments are reconsidered as a part of the multi-compartment fire scenario analysis (see HLR-FSS-E.) Qualitative screening is based on the fire compartments defined in element PP and on the equipment and cable location information provided by elements ES and CS. Any fire compartment that fails to satisfy the qualitative screening criteria is retained for further analysis.
HIGH LEVEL REQUIREMENT FOR QUALITATIVE SCREENING (QLS)
HLR HLR Description HLR Summary (From Review)
HLR-QLS-A The FPRA shall identify those physical analysis units that screen out as individual risk contributors without quantitative analysis.
The licensee did not perform a qualitative screening. This element is not applicable.
HLR-QLS-B The FPRA shall document the results of the qualitative screening analysis in a manner that facilitates FPRA applications, upgrades, and peer review.
The licensee did not perform a qualitative screening. This element is not applicable.
PLANT RESPONSE MODEL ELEMENT This element involves the development of a logic model that reflects the plant response following a fire. The FPRA plant response model is central to the quantification of fire risk and is exercised in the Fire Risk Quantification (FQ) element to quantify conditional core damage probability (CCDP) and conditional large early release probability (CLERP) values for selected fire scenarios. This model is commonly constructed based on an Internal Events PRA model that is then modified to include only those initiating events that can result from a fire, to include unique additional equipment failure modes, such as spurious operation, not addressed in an Internal Events PRA model, and to reflect fire-specific plant procedures and operator actions (e.g., alternate and remote shutdown actions).
HIGH LEVEL REQUIREMENTS FOR FIRE PRA PLANT RESPONSE MODEL (PRM)
HLR HLR Description HLR Summary (From Review)
HLR-PRM-A The FPRA shall include the FPRA plant response model capable of supporting the HLR requirements of FQ.
Two supporting requirements were not met because the licensee has not developed a LERF model at this time. This HLR appeared to be met with respect to core damage frequency and conditional core damage probability.
Modifications to the internal events PRA fault tree model appear to be developed to a level of detail and conventions consistent with those used in the internal event logic. Therefore, solutions of the model will allow determination of the relative contribution and effects of uncertainty of the new component failure modes. The development of the new logic for the fire PRA plant response model assessed equipment in the safe shutdown equipment list and in the PRA model. The scope of components appears to be complete. Refer to F&O findings PRM-A1-1 and PRM-A2-1.
HLR-PRM-B The FPRA plant response model shall include fire-induced initiating events, both fire-induced and random failures of equipment, fire-specific as well as non-fire related human failures associated with safe shutdown, accident progression events (e.g., containment failure modes), and the supporting probability data (including uncertainty) based on the SRs provided under this HLR that parallel, as appropriate, the ASME PRA Standard for Internal Events PRA.
Three supporting requirements are not met for this HLR. All three involve the need to investigate the possibility of typically minor LERF contributors for internal events PRA becoming more important for fire. It appeared that the licensee did review new components and failure modes identified in the Component Selection task and ensured that the model captures those impacts.
The focus of the internal events PRA model, as enhanced for fire, was on quantification of fire-induced CCDP, not CLERP. Two suggestions were made by the review team, involving overly conservative modeling and data-related F&Os from the focused scope peer review conducted in 2007. Refer to F&O finding PRM-B1-01 and F&O suggestions PRM-B8-1 and PRM-B12-1.
HIGH LEVEL REQUIREMENTS FOR FIRE PRA PLANT RESPONSE MODEL (PRM)
HLR HLR Description HLR Summary (From Review)
HLR-PRM-C The FPRA plant response model shall be expanded to include new contributors because of additional spurious operation considerations following a review of the results produced in meeting Section 4.16 of this Standard.
This HLR was not reviewed because it is not clear what is expected in order to comply with the fire PRA standard or how one might accomplish the inferred goal. The purpose is stated as to provide greater assurance than that obtained by meeting the ES and PRM-A and PRM-B SRs that the Fire PRA results capture the most risk-significant contributors including spurious operation type failures that may have been limited in number in the model The fire PRA standard then acknowledges that this is an evolving technical area. The NRC review team decided to not review this requirement.
HLR-PRM-D The FPRA shall document the FPRA plant response model in a manner that facilitates FPRA applications, upgrades, and peer review.
This HLR was met. The model revisions made to account for new fire-induced failure impacts are adequately documented to comply with the internal events standard for documentation of system models. Initiating events, accident sequence, success criteria and data elements do not apply to the scope of new modeling developed.
SUPPORTING REQUIREMENTS FOR PLANT RESPONSE MODEL SR Level Observation Basis Cap Cat PRM-A1 Finding Section 5.3.2 specifically states that no specific Conditional Large Early Release Probability (CLERP) model was developed.
F&O PRM-A1-1 Not Met PRM-A2 Finding No LERF model developed; see related finding on PRM-A1 for CLERP.
F&O PRM-A2-1 Not Met PRM-A3 Summary Modifications to the internal events PRA fault tree model appear to be developed consistent with the level of detail and conventions used in the internal event logic. Therefore, solutions of the model will allow determination of the relative contribution of the new component failure modes.
Met PRM-A4 Summary Modifications to the internal events PRA fault tree model appear to be developed consistent with the level of detail and conventions used in the internal event logic. Therefore, solutions of the model will allow determination of the effects of uncertainty of the new component failure modes.
Met PRM-A5 Summary The development of the new logic for the fire PRA plant response model assessed both equipment in the safe shutdown equipment list for addition to the PRA model, and equipment in the PRA model for addition to the safe shutdown equipment list. Therefore, the scope of components appears to be complete. The review did not attempt to validate the locations of cables for the new equipment.
Met PRM-A6 Summary Modifications to the internal events PRA fault tree model appear to be developed consistent with the level of detail and conventions used in the internal event logic. Therefore, the new logic is consistent with the relevant HLRs referenced.
Met PRM-B1 Finding Need to investigate the possibility of typically minor LERF contributors for internal events PRA becoming more important for fire.
F&O PRM-B1-1 Not Met PRM-B2 Summary As stated in HNP-F/PSA-0077, "Review of the Initiating Events PRA Event Tree and Accident Sequence documentation revealed no changes to the current accident progression sequences. However, there will be new fault tree logic to account for some events that were previously screened for internal events (see Table 6-2 [which indicates no new initiating events, but the reintroduction of some that were previously screened {typically due to low frequency}])."
Met PRM-Summary This element is not applicable because new N/A
SUPPORTING REQUIREMENTS FOR PLANT RESPONSE MODEL SR Level Observation Basis Cap Cat B3 initiating events were not identified.
PRM-B4 Summary This element is not applicable because new initiating events were not identified.
N/A PRM-B5 Summary This element is not applicable because new initiating events were not identified.
N/A PRM-B6 Summary This element is not applicable because new or modified success criteria is not identified.
N/A PRM-B7 Summary This element is not applicable because new or modified success criteria were not identified.
N/A PRM-B8 Summary See additional entries made for internal events SRs referenced by the fire standard.
Met PRM-B8 Summary SY-A4 - a multi-disciplined group including Engineering and Operations staff was used to identify the new failure modes required for fire-induced failures including spurious operations. This approach clearly satisfies capability category I. Capability category II specifically requires walkdowns and interviews. Walkdowns are judged to not directly apply to the system modeling aspects of these new failure modes (which are essentially new components and/or failure methods of existing components). The multi-disciplined team approach is considered superior to interview techniques required by the standard at capability category II.
Therefore, it is concluded that SY-A4 is met at capability category II for the modifications made to the internal events model for fire-induced failures.
2 PRM-B8 Summary SY-A7 - A detailed system model is provided for each new fire-induced failure mode, which satisfies Capability Category III for this SR.
3 PRM-B8 Summary SY-A - All other SRs from the internal events standards, not specifically discussed in other Summary observations, are either met or not directly applicable to the new fire system modeling.
SY-B - For the new modeling, CCF is not directly included as appropriate; single fire scenarios which can cause the failure of redundant components will occur based on proper identification of the cable locations relative to each particular fire scenario.
Therefore, for system modeling, SRs in SY-B are not applicable.
PRM-B8 Suggestion SY-A20 - Model should be revised to realistically reflect the system impacts and credit potential recovery actions.
F&O PRM-B8-1
SUPPORTING REQUIREMENTS FOR PLANT RESPONSE MODEL SR Level Observation Basis Cap Cat PRM-B9 Summary The documentation does not identify any PRA components not selected for detailed cable routing, and therefore this element is not directly applicable.
N/A PRM-B10 Summary Existing HFEs from the internal events model were re-evaluated for fire effects. However, the new modeling for fire-induced failures do not include any new operator actions.
Met PRM-B11 Summary New failure modes used existing internal events failure modes. For fire scenarios, the fire-induced failure mode of cable faults is addressed during the quantification process, not directly in the fault tree model.
HNP-F/PSA-0001, Rev. 8, Attachment 1, documents changes to the internal events PRA model necessitated by the update to the integrated model including the Fire PRA.
Included are new basic events and existing basic events requiring assignment of new or modified probabilities.
Met PRM-B12 Suggestion Review the DA-related F&O's from the 12/2007 Focused Scope Peer Review to ensure no effect on the Fire PRA.
F&O PRM-B12-1 Met PRM-B13 Finding Need to investigate the possibility of typically minor LERF contributors for internal events PRA becoming more important for fire.
F&O PRM-B1-1 Not Met PRM-B14 Finding Need to investigate the possibility of typically minor LERF contributors for internal events PRA becoming more important for fire.
F&O PRM-B1-1.
Not Met PRM-C1 Comment on Standard Problem with Fire PRA Standard Not Rev PRM-D1 Summary The model revisions made to account for new fire-induced failure impacts are adequately documented to comply with the internal events standard for documentation of system models. Initiating events, accident sequence, success criteria and data elements do not apply to the scope of new modeling developed.
Met
FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-05 ID Number: PRM-A1-1 Level of Significance: Finding Reviewer: AJH Capability Category: Not Met OBSERVATION:
Section 5.3.2 specifically states that no specific conditional LERF model was developed.
BASIS FOR LEVEL OF SIGNIFICANCE:
POSSIBLE RESOLUTION (REVIEWER):
If required for an application, the LERF model must be developed and peer reviewed.
Reference(s):
Personnel Contacted:
HNP-F/PSA-0076 R0
FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-05 ID Number: PRM-A2-1 Level of Significance: Finding Reviewer: AJH Capability Category: Not Met OBSERVATION:
See related finding on PRM-A1 for CLERP.
BASIS FOR LEVEL OF SIGNIFICANCE:
Refer to PRM-A1 POSSIBLE RESOLUTION (REVIEWER):
Reference(s):
Personnel Contacted:
HNP-F/PSA-0076 R0
FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-05 ID Number: PRM-B1-1 Level of Significance: Finding Reviewer: RHG Capability Category: Not Met OBSERVATION:
This SR is Not Met. As stated in HNP-F/PSA-0077, "In Task 5, new components and failure modes identified in the Component Selection task (Task 2) were reviewed for possible inclusion into the Internal Events PRA model. The Internal Events PRA model was then modified to capture the impact of new components or failure modes identified in Task 2. Task 5 was focused on the enhancement of the Internal Events PRA model to allow quantification of fire-induced CCDP. A LERF top event for Conditional Large Early Release Probability (CLERP) was not developed [for several reasons {as listed}]..." Also, to satisfy the Discussion, the internal events PRA has been reviewed against ASME-RA-2002/RA-Sb-2005 as documented by the 2006 "Gap Analysis" against RG-1.200. Despite the preceding, this assumed subsumation of LERF within CDF based on assuming that the internal events PRA major LERF contributors (SGTR and ISLOCA) constitute the only major LERF contributors for the Fire PRA, may not cover the possibility of a typically minor LERF contributor to the internal events PRA becoming a more important LERF contributor for fire (e.g., spurious opening of non-ISLOCA-related CNMT penetrations). Finding F&O PRM-B1-01 cites the need to investigate the possibility of typically minor LERF contributors for internal events PRA becoming more important for fire, at least before concluding that only the major internal events LERF contributors could be the only major ones for fire.
BASIS FOR LEVEL OF SIGNIFICANCE:
Finding F&O PRM-B1-01 cites the need to investigate the possibility of typically minor LERF contributors for internal events PRA becoming more important for fire, at least before concluding that only the major internal events LERF contributors could be the only major ones for fire.
POSSIBLE RESOLUTION (REVIEWER):
Reference(s):
Personnel Contacted:
P-F/PSA-0077
FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-06 ID Number: PRM-B8-1 Level of Significance: Suggestion Reviewer: AJH Capability Category:
SY-A20 - The model for some spurious failures is conservative, in that actual system capability may still allow the system function to be achieved. For example:
- 1. The fire-induced opening of a SG PORV or steam dump valve is assumed to cause the affected SG to be faulted and unavailable for decay heat removal. In reality, the plant may only be cooling down at a nominal rate consistent with TS and procedures (albeit in an uncontrollable condition). Failing secondary heat removal (event B in the transient event tree logic) for this condition is conservative.
- 2. The failure of control and isolation valves for a steam generator AFW supply from the motor-driven pump header is assumed to cause SG overfill and subsequent unavailability of that steam generator to supply steam to the turbine-driven AFW pump. However, at least one MDAFW pump must be operating, and therefore the unavailability of the turbine-driven AFW pump would not be a concern. For fire scenarios, it is therefore implicitly assumed that the MDAFW pump does not fail until after the control and isolation valves fail and the SG is lost, which may be overly conservative for some specific fire scenarios, depending upon the physical location of the cables.
- 3. Failure to isolate the non-essential chilled water components is identified as a chilled water system failure. This is overly conservative since these non-essential components are normally supplied by the system. In fact, the internal events model was subsequently revised to add a required piping failure. Currently, the licensee staff is considering a new failure mode related to this failure to isolate the non-essential components due to cross-train water inventory issues. A more careful review of the actual failure effects of not isolating the non-essential header would seem to be warranted.
- 4. It does not appear that the failure mode of draining the RWST to the containment sumps vial the RHR and containment spray pump suctions is crediting potential operator action to isolate the flowpath, Since there are examples of conservative modeling of the system impacts, this SR is only met at capability category I.
FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-06 ID Number: PRM-B8-1 Level of Significance: Suggestion Reviewer: AJH Capability Category:
BASIS FOR LEVEL OF SIGNIFICANCE:
POSSIBLE RESOLUTION (REVIEWER):
Model should be revised to realistically reflect the system impacts and credit potential recovery actions. If these failure modes are not important to the overall fire PRA results, then no changes would be necessary, and the remaining modeling would satisfy capability category II.
Reference(s):
Personnel Contacted:
FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-05 ID Number: PRM-B12-1 Level of Significance: Suggestion Reviewer: RHG Capability Category: Met OBSERVATION:
This SR is Met, based on the related SRs from DA in ASME RA-Sb-2005, to which this SR (PRM-B12) refers. All FPRA PRM probability input values from PRM-B11 underwent data analysis in the same way as performed in the original internal events PRA and its subsequent updates. Therefore, it was judged that the evaluations of the previous internal events SRs applied here. All relevant SRs under HLR-DA from the 2006 "Gap Analysis" were graded as Met or at least CC-II (or CC-I/II, i.e., none were Not Met or solely CC-I). The recent (12/2007)
"Focused Scope" Peer Review of HLR-DA identified three SRs that did not meet CC-II (two were Not Met and one was CC-I). The associated F&O's were mainly associated with (1) failure to estimate the time for which MOVs are configured in standby (DA-C8-01); (2) component boundaries and selection of CCF parameter values (DA-D6-01 thru 03); and (3) screening out failure events when followed by successful operation shortly afterward, when it would be better if these were treated as failure followed by success to account for possibility of < 1 hr being available during emergency (chiller trip, followed by restart; DA-C4-01). It is unlikely any of these would significantly affect the results of the Fire PRA if not resolved, but this should be examined and, if necessary, the F&O's should be resolved quickly. Attachment 1 to HNP-F/PSA-0001, Rev. 8, lists all basic events for which probability values were updated (or added for the first time, if the basic event was new) as per the changes/additions discussed in SR PRM-B11. Updates/additions were made for plant-specific unavailabilities due to scheduled and unscheduled maintenance, initiating events, MOVs and CCFs. Included among these were updates/additions for fire-related basic events and initiators. Suggestion F&O PRM-B12-01 is to (1) review the DA-related F&O's from the 12/2007 Focused Scope Peer Review to ensure no effect on the Fire PRA (and resolve quickly if there is an effect) and (2) add discussion and references to HNP-F/PSA-0001, Rev. 8, Att. 1, to the Fire PRA summary documents regarding these data uupdates/additions for fire-related events.
BASIS FOR LEVEL OF SIGNIFICANCE:
Suggestion F&O PRM-B12-01 is to (1) review the DA-related F&O's from the 12/2007 Focused Scope Peer Review to ensure no effect on the Fire PRA (and resolve quickly if there is an effect) and (2) add discussion and references to HNP-F/PSA-0001, Rev. 8, Att. 1, to the Fire PRA summary documents regarding these data uupdates/additions for fire-related events.
FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-05 ID Number: PRM-B12-1 Level of Significance: Suggestion Reviewer: RHG Capability Category: Met POSSIBLE RESOLUTION (REVIEWER):
Reference(s):
Personnel Contacted:
HNP-F/PSA-0001, Rev. 8, Att. 1; 12/2007 "Focused Scope" Peer Review Dave Miskiewicz; Steve Mabe FIRE SCENARIO SELECTION AND ANALYSIS ELEMENT In this element, fire scenarios are selected, defined, and analyzed in order to represent the collection of fire events that might contribute to plant fire risk. The purpose of the fire scenario analysis is to quantify the likelihood that, given ignition of a fire, fire-induced damage to selected equipment and cables (as defined in the ES and CS elements) occurs. The result is expressed for each fire scenario as a) a set of cable and equipment failures, including specification of the failure modes, reflecting the loss of a specific set of damage targets and b) a conditional probability that given the fire, the postulated cable and equipment failures are realized (potentially including both a severity factor and a non-suppression probability). These results are fed forward to the FQ element for incorporation into the final risk calculations.
HIGH LEVEL REQUIREMENTS FOR FIRE SCENARIO SELECTION AND ANALYSIS (FSS)
HLR HLR Description HLR Summary (From Review)
HLR-FSS-A The FPRA shall select one or more combinations of an ignition source and damage target sets to represent the fire scenarios for each unscreened physical analysis unit upon which estimation of the risk contribution (CDF and LERF) of the physical analysis unit will be based.
All supporting requirements were met except FSS-A2, which involves specifying the equipment and cable failures for each target set. The licensee assumed that cables were the only important targets; the lower damage threshold for critical equipment targets was not considered.
Also, the zone of influence for transient fires did not account for wall and corner effects. Refer to F&O finding FSS-A2-1 and suggestions FSS-A1-1 and FSS-A2-2.
HLR-FSS-B The FPRA shall include an analysis of potential fire scenarios leading to the MCR abandonment.
All supporting requirements for this HLR were met except FSS-B1, involving lost/degraded functions leading to control room abandonment.
Refer to F&O finding FSS-B1-1.
HLR-FSS-C The FPRA shall characterize the factors that will influence the timing and extent of fire damage for each combination of an ignition source and damage target sets selected per HLR-FSS-A.
All supporting requirements for this HLR were met except FSS-C5, because the only target item considered was cable. Other targets, such as solid-state control components, have a much lower damage threshold.
Refer to F&O finding FSS-C5-1.
HLR-FSS-D The FPRA shall quantify the likelihood of risk-relevant consequences for each combination of an ignition source and damage target sets selected per HLR-FSS-A.
All supporting requirements for this HLR were met except FSS-D1, because of excessive conservatism in the fire modeling. Detailed fire modeling or other, more realistic approaches may be required for high risk areas. Refer to F&O finding FSS-D1-1 and suggestion FSS-D1-2.
HLR-FSS-E The parameter estimates used in fire modeling shall be based on relevant generic industry and plant-specific information. Where feasible, generic and plant-specific evidence shall be integrated using acceptable methods to obtain plant-specific All supporting requirements for this HLR were met except FSS-E3, which involves uncertainty analysis. Uncertainty had not been addressed by the licensee as of the time of the staff review. Refer to F&O finding FSS-E3-
- 1.
HIGH LEVEL REQUIREMENTS FOR FIRE SCENARIO SELECTION AND ANALYSIS (FSS)
HLR HLR Description HLR Summary (From Review) parameter estimates. Each parameter estimate shall be accompanied by a characterization of the uncertainty.
HLR-FSS-F The FPRA shall search for and analyze risk-relevant scenarios with the potential for causing fire-induced failure of exposed structural steel.
This HLR was not reviewed because the fire PRA model was not complete: The licensee had not analyzed risk-relevant scenarios with the potential for causing fire-induced failure of exposed structural steel. Refer to F&O finding FSS-F-1.
HLR-FSS-G The FPRA shall evaluate the risk contribution of multi-compartment fire scenarios.
This HLR was not reviewed because the fire PRA model was not complete: The licensee had not evaluated the risk contribution of multi-compartment fire scenarios. Refer to F&O finding FSS-G-1.
HLR-FSS-H The FPRA shall document the results of the fire scenario and fire modeling analyses including supporting information for scenario selection, underlying assumptions, scenario descriptions, and the conclusions of the quantitative analysis, in a manner that facilitates FPRA applications, upgrades, and peer review.
The documentation supporting requirements for this HLR were met with the exception of two areas that have not been performed by the licensee:
fire-induced failure of exposed structural steel and uncertainty analysis. It was noted that the documentation could be improved by adding a cross-reference or list showing where all the related information is found (road map). See F&O findings FSS-H8-1 and FSS-H9-1, and suggestion FSS-H1-1.
SUPPORTING REQUIREMENTS FOR FIRE SCENARIO SELECTION AND ANALYSIS SR Level Observation Basis Cap Cat FSS-A1 Suggestion The walkdown database needs to reflect the final transient ignition source mapping.
F&O FSS-A1-1 Met FSS-A2 Finding Need to consider non-cable targets with lower damage threshold (e.g., sensitive electronic equipment). Need to account for wall and corner effects for transient combustible fires.
F&O FSS-A2-1 Not Met FSS-A2 Suggestion The screening approach used to determining the time to generate a hot gas layer is considered to be potentially very conservative.
F&O FSS-A2-2 FSS-A3 Summary Progress decided that initially, no primary systems would be summarily counted as failed in a fire scenario. Therefore, no PRA components were excluded from comparison against the Safe Shutdown components based on these system and functional differences. A phased process is expected where initial quantification will assume that certain systems (non-App-R credited secondary plant systems such as de-mineralized water, condensate, and main feedwater) are failed. Based on importance, specific equipment/circuits will be credited, subject to determination of cable routing data. After initial quantification: de-mineralized water, instrument air, condensate, and main feed water system cables routed and those cables routing data is now in the FSSPMD. Progress does not use assumed cable routing.
Met FSS-A4 Summary The scoping walkdown calculation (HNP-F/PSA-0078), results in a Source-Target Relationship Table (Attachment 2), which represents the fire sources and related target sets in each fire compartment. This table is a subset of the HNP-FPRA database which groups the scenario specific target sets so the fire compartment impacts can be analyzed. In addition, HGL is calculated for each fire compartment and associated cable failures are tabulated in another database. Multiple databases are used for FRANC runs which characterize the credible range of impacts to systems and SSA functions.
Met FSS-A5 Summary Progress has developed sufficient variety of data (HNP_FPSA Database) to quantify the risk from multiple ignition sources and associated targets with in each fire compartment. Their database is extensive enough to correlate the risk contribution from specific ignition sources and/or fire scenarios with in each fire compartment. Their quantification process 3
SUPPORTING REQUIREMENTS FOR FIRE SCENARIO SELECTION AND ANALYSIS SR Level Observation Basis Cap Cat calculation (HNP-F/PSA-0079) documents their process and attachment 2 provides the risk for each fire compartment from the top 5 ignition sources, including the ZOI CDF, HGL CDF, and total CDF.
FSS-A6 Summary Based on review of Main Control Room Analysis Rev D Draft.pdf.
Met FSS-B1 Finding Lost/degraded functions should be clarified/discussed in the documentation of the control room abandonment analysis.
F&O FSS-B1-1 Not Met FSS-B2 Summary Each panel in the MCR was sub-divided and fires postulated in each sub-division. Scenarios for fire suppress and non-suppressed were evaluated.
3 FSS-C1 Summary Assumptions From Page 35 of 200 of HNP-F/PSA-0079 2
FSS-C2 Summary Each Fire Area has been analyzed. The time-dependent fire growth profile that was used can be found in the spreadsheets located in C:\\PRA\\HNP\\FPRA_FRANC.
2&3 FSS-C3 Summary Data on fire heat release rate decay profile was obtained from NUREG/CR 6850 Appendix G.
Reason for Category 2&3 is that the licensee attempted to use a more realistic fire growth rate which included consideration of possible fire spread. Each Fire Area has been analyzed.
2&3 FSS-C4 Summary Each Fire Area has been analyzed. Section 5.5.2 of HNP-F/PSA-0079 references how severity factor is calculated and used.
3 FSS-C5 Finding Only target item considered was cable. No other targets such as solid state control components were considered. See NUREG/CR 6850 Appendix H Section H.2. Solid State failure criteria is 3kW/m2 and 65 °C.
F&O FSS-C5-1 Not met FSS-C6 Summary Assumption is made that as soon as target is in HGL, damage occurs. The nearest target is always located in the plume and not in the flame, ceiling jet, or radiation regions. Page 35 of HNP-F/PSA-0079. Note: only item considered as a target was cable.
1&2 FSS-C7 Summary Following are assumptions that were made and are located inHPN-F/PSA-0079 page 9:
- 1. If no detection system is installed manual detection will occur in 15 minutes.
- 2. Fires initiated in the presence of a fire watch will not propagate to a HGL due to early manual suppression actions.
Met
SUPPORTING REQUIREMENTS FOR FIRE SCENARIO SELECTION AND ANALYSIS SR Level Observation Basis Cap Cat
- 3. Continuous fire watch personnel are brigade qualified and will take first action to suppress an observed fire within 2 minutes.
- 4. Fire brigade response times applied are 50%
of the drill times based on feedback from HNP fire protection.
- 5. Incipient detection of low voltage cabinets provides additional 60 minutes for manual suppression Recovery of a failed suppression system was not considered.
FSS-C8 Summary The licensee did take credit for fire wrap.
Documented technical basis. Confirmed the mechanical damage criteria, and direct flame impingement criteria. Page 12 of HNP-M/MECH-1103 Met FSS-D1 Finding Used HNP-M/MECH-1128 Hot Gas Layer Calculations and HNP-M/MECH-1129 Fire Zone of Influence Calculations in walk downs.
Also used spreadsheet calculations that they developed. These spreadsheets appear to give very conservative results and can be located in C:\\PRA\\HNP\\FPRA_FRANC Did not use detailed fire modeling such as CFAST or FDS F&O FSS-D1-1 Not Met FSS-D1 Suggestion Current calculation method for determining time to HGL formation is overly conservative. More detailed fire modeling may be required for high risk areas. Conservative fire modeling is not appropriate for high risk areas. Need to use other computer fire models, i.e., CFAST, FDS to further analyze rooms of interest.
F&O FSS-D1-2 FSS-D2 Summary Used HNP-M/MECH-1128 Hot Gas Layer Calculations and HNP-M/MECH-1129 Fire Zone of Influence Calculations in walk downs.
Also used spreadsheet calculations that they developed. These spreadsheets appear to give very conservative results and can be located in C:\\PRA\\HNP\\FPRA_FRANC.
Did not use detailed fire modeling such as CFAST or FDS.
Met FSS-D3 Summary Used HNP-M/MECH-1128 Hot Gas Layer Calculations and HNP-M/MECH-1129 Fire Zone of Influence Calculations in walk downs.
Also used spreadsheet calculations that they 1
SUPPORTING REQUIREMENTS FOR FIRE SCENARIO SELECTION AND ANALYSIS SR Level Observation Basis Cap Cat developed. These spreadsheets appear to give very conservative results and can be located in C:\\PRA\\HNP\\FPRA_FRANC.
Did not use detailed fire modeling such as CFAST or FDS.
FSS-D4 Summary Based on review of
- FPIP-0208 Scoping Fire Modeling Revision 2
- Associated Spreadsheets located in C:\\PRA\\HNP\\FPRA_FRANC.
- HNP-M/MECH-1128 Hot Gas Layer Calculations
- HNP-M/MECH-1129 Fire Zone of Influence Calculations Met FSS-D5 Summary Used 75th and 98th percentile. HRR HNP-M/MECH-1128 Hot Gas Layer Calculations references a simple statistical dimensionless correlation for evaluating fire growth in a compartment (hot gas layer temperature) with natural ventilation.
FPIP 0206 references using Plant Specific Bayesian Updates 3
FSS-D6 Summary Based on review of:
- HNP-M/MECH-1128 Hot Gas Layer Calculations
- HNP-M/MECH-1129 Zone Of Influence Calculations
- FPIP-0208 Scoping Fire Modeling Revision 2 Met FSS-D7 Summary Based on review of:
- Spreadsheets provided by licensee
- NUREG/CR-6850 1
FSS-D8 Summary Based on review of:
- Spreadsheets provided by licensee
- NUREG/CR-6850 Met FSS-D9 Summary Smoke damage to FPRA equipment was not considered. There is No Requirement under Capability Category 1 for this SR. They automatically meet Capability Category 1.
1 FSS-D10 Summary Based on review of:
- Att2(Source-Target).pdf
- Att3(Fixed Walkdown).pdf
- Att4(Transient Walkdown).pdf 2&3 FSS-D11 Summary Based on review of:
- Att2(Source-Target).pdf
- Att3(Fixed Walkdown).pdf
- Att4(Transient Walkdown).pdf Met FSS-E1 Summary Based on review of:
- HNP-M/MECH-1128 Hot Gas Layer Met
SUPPORTING REQUIREMENTS FOR FIRE SCENARIO SELECTION AND ANALYSIS SR Level Observation Basis Cap Cat Calculations
- HNP-M/MECH-1129 Zone Of Influence Calculations
- FPIP-0208 Scoping Fire Modeling Revision 2
- FPIP-0206 FIRE PRA Fire Ignition Frequency FSS-E2 Summary For fire modeling parameters, generic estimations were used from the referenced documents. For the spreadsheets developed by the licensee, expert judgment was used in developing the fire growth rates.
Met FSS-E3 Finding No uncertainty analysis was performed.
F&O FSS-E3-1 Not met FSS-E4 Other No assumptions were made on cable routing N/A FSS-F Finding Did not perform this task F&O FSS-F-1 Not Rev FSS-G Finding Did not perform this task F&O FSS-G-1 Not Rev FSS-H1 Summary Much of the documentation done by both the licensee and/or contractors was extensive and in some cases very detailed. However, the information was difficult to find. It would be very helpful, if for a particular SR, the associated document and section within the document be listed.
Met FSS-H1 Suggestion Need to list where documents are located.
F&O FSS-H1-1 FSS-H2 Summary Same comment as FSS-H1 Documents for where this information can be found are listed in the referenced documents.
1 FSS-H3 Summary Same comment as FSS-H1 Documents for where this information can be found are listed in the referenced documents.
Met FSS-H4 Summary Same comment as FSS-H1 Documents for where this information can be found are listed in the referenced documents.
Met FSS-H5 Summary Same comment as FSS-H1 Documents for where this information can be found are listed in the referenced documents.
Justification for Capability Category 1 is that the licensee did not include any uncertainty evaluations.
1 FSS-H6 Summary Same comment as FSS-H1 Documents for where this information can be found are listed in the referenced documents.
Justification for Capability Category 1 is that the licensee provided a method for applying statistical models for plant specific updates, see SR FSS-D-5, however there was no updates
- made, 1
FSS-Summary FPIP-0150 Ignition Source Characterization Met
SUPPORTING REQUIREMENTS FOR FIRE SCENARIO SELECTION AND ANALYSIS SR Level Observation Basis Cap Cat H7 Section 9.6 documents assumptions made.
FSS-H8 Finding No multi compartment fire scenarios were considered.
F&O FSS-H8-1 Not Met FSS-H9 Finding No work on uncertainties was done F&O FSS-H9-1 Not Met FSS-H10 Summary Same comment as FSS-H1 Documents for where this information can be found are listed in the referenced documents.
Met
FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-07 ID Number: FSS-A1-1 Level of Significance: Suggestion Reviewer: PWL Capability Category: Met OBSERVATION:
Scoping fire modeling instructions (FPIP-0208) provide instructions to identifiy fixed and transient fire scenarios. The instruction screens out sources that wont cause target damage, however, fire PRA component sources would not be screened. For transient sources, there positioning will effect at least one target, could reasonably assumed to be in that location, placed roughly every 1000 square feet, and located on the floor near cable tray risers, low-lying cable trays, areas without train separation, or groups of conduits. A 3' by 3' (trash bag) size transient source was used with a 143 kW and 317 kW ZOI. Transients were not postulated in locked high radiation areas, small rooms, or rooms that fixed sources hit all targets.
FPRA walkdown instruction (FPIP-0200) included mapping out fixed ignition sources and identifying existing transient combustible sources, but not locating postulated transient sources.
The fire ignition frequency calculation (HNP-F/PSA-0071) assumes all fixed ignition sources were identified during the walkdowns. Attachment 8 contains a list identifying over 2900 fixed ignition sources. Attachment 10 maps the fixed ignition sources of plant plan views. It was noted that diesel fuel oil storage fire areas were not walked downed, since the fire compartments are basically the storage tank. The calc noted placement of transient sources was chosen for locations where a transient fire would reasonably assume to be placed during routine work.
Progress Energy conducted a transient fire ignition source frequency evaluation to identify risk relevant transient source location. They considered the following; given the nature of transients it is possible to have multiple plausible locations within a compartment. General transient locations are postulated in every room except those that are locked high radiation areas or small rooms where a transient fire is assumed to damage all targets.
Additional plant walkdowns were done to identify targets from transients sources (HNP-F/PSA-0078). Attachment 4 mapped the locations of the transients and the HNP_FPRA_Database indicated about 250 transient sources were considered, with about 90 of these sources were credited for failing all targets in their associated fire compartment. Comparison of the mapped transient locations, walkdown sheets, walkdown validation sheet, and the source target relationship targets for fire area 12-A-BAL, fire zone 12-A-5-DIH (FC01) showed some inconsistencies between mapped transient numbers did not have a walkdown sheets and one walkdown sheet (T-9) showed a target (C1223) as a tray, when the source-target database showed it was a riser. Progress researched this inconsistencies and noted that those walkdown sheets were preliminary and transient locations were consolidated if two sources hit the same targets and are redundant.
FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-07 ID Number: FSS-A1-1 Level of Significance: Suggestion Reviewer: PWL Capability Category: Met BASIS FOR LEVEL OF SIGNIFICANCE:
Licensee should take into consideration the vertical height of transient ignition sources.
The walkdown database needs to reflect the final transient ignition source mapping.
POSSIBLE RESOLUTION (REVIEWER):
Reference(s):
Personnel Contacted:
PI-FPIP-NGG-0200, Rev 3 Draft FPIP-0208, Rev 2 Draft HNP-F/PSA-0071, Rev 1 Draft HNP-F/PSA-0078, Rev 0 HNP_FPRA_database Dave Miskiewicz Ricky Davis-Zapata
FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-07 ID Number: FSS-A2-1 Level of Significance: Finding Reviewer: PWL Capability Category: Not Met OBSERVATION:
Progress Energy developed Zones of Influence (ZOI) for the 98 and 75 percentile fires for different fire sources (MM/MECH-1128) and calculated vertical and horizontal distances from a source fire that would damage cable (i.e., target). Progress also developed a Hot Gas Layer (HGL) methodology (MM/MECH-1129) which correlates Heat Release Rate (HRR) needed in a room to cause a HGL to a certain length of cable tray needed to obtain that HRR. If a fire compartment develops a HGL, Progress assumes all targets will be damaged. Progress utilized the damage of the Kerite cable temperature (400 F) as the damage threshold. These Calcs are reviewed in later SRs.
Progress Energy utilized their ZOI distances and the postulated cable tray length needed to generate a HGL to conduct walkdowns to identfy target sets. Progress sketched and photographed each source for there database. Project instruction FPIP-0200, provides the walkdown instruction and F/PSA-0078 provides the scoping walkdown calculation. In the calc, attachment 3 provides the fixed source walkdowns data sheets. These sheets did not consider damage to critical equipment, which has a lower threshold temperature and a larger ZOI, so some targets may have been missed. Attachment 4 provides the transient walkdown data sheets and these sheets did not consider wall and corner fire ZOIs. These fires create larger ZOIs so the walkdowns may have miss some potential targets. Attachment 2 provides a source to target database, with over 21,000 target sets.
BASIS FOR LEVEL OF SIGNIFICANCE:
The lower damage threshold for critical equipment targets were not considered. ZOI for transient wall and corner fire sources were not used and some targets may have been missed.
POSSIBLE RESOLUTION (REVIEWER):
Reference(s):
Personnel Contacted:
Draft HNP-NN/MECH-1128 Draft HNP-NN/MECH-1129 PI-FPIP-NGG-0200, Rev 3 Draft HNP-F/PSA-0078, Rev 0
FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-08 ID Number: FSS-A2-2 Level of Significance: Suggestion Reviewer: GWP Capability Category:
OBSERVATION:
The screening approach to determining the time to generate a hot gas layer is considered to be potentially very conservative. The approach compares two curves. The first is a measure of the time at which the total heat deposited at a given heat release rate is sufficient to generate a hot gas layer. The assumption underlying this curve is that the fire grows instantaneously to its maximum heat release rate. The second curve expresses the growth of heat release rate as a function of time. The time to development of a hot gas layer is the time given by the intersection of these two curves. This is incorrect since the first curve is based on the total heat deposited in the fire area, while second curve is a plot of the instantaneous heat release rate as a function of time. It is the area under this curve that provides the total heat deposited as a function of time.
The approach to determining the time to hot gas layer is conservative on two counts: firstly, because of the assumption of an instantaneous fire to generate the first curve, and secondly, because the comparison is made using the instantaneous heat release rate rather than the integral.
The use of the screening approach, while technically incorrect, is adequate for demonstrating that a fire scenario is an insignificant contributor to risk. However, any scenarios that contribute to fire risk for which the assessment is based on the timing developed using this method, should be characterized as very conservative BASIS FOR LEVEL OF SIGNIFICANCE:
POSSIBLE RESOLUTION (REVIEWER):
Reference(s):
Personnel Contacted:
FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-05 ID Number: FSS-B1-1 Level of Significance: Finding Reviewer: RHG Capability Category: Not Met OBSERVATION:
Main Control Room Analysis Rev D Draft.pdf page A-28 discusses control room abandonment.
Finding: Loss/degraded functions are not clearly included in the control room abandoment analysis. This should be clarified/discussed in the documentation.
BASIS FOR LEVEL OF SIGNIFICANCE:
POSSIBLE RESOLUTION (REVIEWER):
Reference(s):
Personnel Contacted:
Main Control Room Analysis Rev D Draft.pdf SHNPP_Ctrl Room Report DRAFT_12 2007_B.pdf Dave Miskiewicz
FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-05 ID Number: FSS-C5-1 Level of Significance: Finding Reviewer: RXV Capability Category: Not met OBSERVATION:
Only target item considered was cable. The damage criteria used for cables is 205 °C (Page 35 of HNP-F/PSA-0079). No other damage criteria used. NUREG/CR-6850 Appendix H page H10 indicates that if a scenario should arise involving solid state control components as a thermal damge target, the failure criteria to be applied is screening are 3kW/m2 and 65 °C.
BASIS FOR LEVEL OF SIGNIFICANCE:
POSSIBLE RESOLUTION (REVIEWER):
Reference(s):
Personnel Contacted:
HNP-F/PSA-0079 Appendix H of NUREG/CR-6850 Ricardo Davis David Miskiewicz
FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-06 ID Number: FSS-D1-1 Level of Significance: Finding Reviewer: RXV Capability Category: Not Met OBSERVATION:
Used HGL and ZOI in walk downs.
Also used spreadsheet calculations that they developed. Appears to give very conservative results.
Did not use detailed fire modeling such as CFAST or FDS BASIS FOR LEVEL OF SIGNIFICANCE:
More detailed fire modeling may be required for high risk areas. Conservative fire modeling is not appropriate for high risk areas. Need to use other computer fire models, i.e., CFAST, FDS to further analyze rooms of interest.
POSSIBLE RESOLUTION (REVIEWER):
Reference(s):
Personnel Contacted:
FPIP-0208 Scoping Fire Modeling Revision 2 Spreadsheets located in C:\\PRA\\HNP\\FPRA_FRANC HNP-M/MECH-1128 Hot Gas Layer Calculaitons HNP-M/MECH-1129 Fire Zone of Influence Calculation
FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-07 ID Number: FSS-D1-2 Level of Significance: Suggestion Reviewer: GWP Capability Category:
OBSERVATION:
The screening approach to determining the time to generate a hot gas layer is considered to be potentially very conservative. The approach compares two curves. The first is a measure of the time at which the total heat deposited at a given heat release rate is sufficient to generate a hot gas layer. The assumption underlying this curve is that the fire grows instantaneously to its maximum heat release rate. The second curve expresses the growth of heat release rate as a function of time. The time to development of a hot gas layer is the time given by the intersection of these two curves. This is incorrect since the first curve is based on the total heat deposited in the fire area, while second curve is a plot of the instantaneous heat release rate as a function of time. It is the area under this curve that provides the total heat deposited as a function of time.
The approach to determining the time to hot gas layer is conservative on two counts: firstly, because of the assumption of an instantaneous fire to generate the first curve, and secondly, because the comparison is made using the instantaneous heat release rate rather than the integral.
The use of the screening approach, while technically incorrect, is adequate for demonstrating that a fire scenario is an insignificant contributor to risk. However, any scenarios that contribute to fire risk for which the assessment is based on the timing developed using this method, should be characterized as very conservative, and considered for more detailed fire analysis BASIS FOR LEVEL OF SIGNIFICANCE:
POSSIBLE RESOLUTION (REVIEWER):
Reference(s):
Personnel Contacted:
FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-06 ID Number: FSS-E3-1 Level of Significance: Finding Reviewer: RXV Capability Category: Not met OBSERVATION:
No uncertainity analysis was performed.
BASIS FOR LEVEL OF SIGNIFICANCE:
POSSIBLE RESOLUTION (REVIEWER):
Reference(s):
Personnel Contacted:
FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-07 ID Number: FSS-F-1 Level of Significance: Finding Reviewer: PWL Capability Category: Not Met OBSERVATION:
Perform the tasks associated with fire PRA standard high level requirement FSS-F and document. Self-assess to the supporting requirements of HLR FSS-F. Have the completed work peer reviewed per the fire PRA standard requirements.
BASIS FOR LEVEL OF SIGNIFICANCE:
POSSIBLE RESOLUTION (REVIEWER):
Reference(s):
Personnel Contacted:
FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-07 ID Number: FSS-G-1 Level of Significance: Finding Reviewer: PWL Capability Category: Not Met OBSERVATION:
Perform the tasks associated with fire PRA standard high level requirement FSS-G and document. Self-assess to the supporting requirements of HLR FSS-G. Have the completed work peer reviewed per the fire PRA standard requirements.
BASIS FOR LEVEL OF SIGNIFICANCE:
POSSIBLE RESOLUTION (REVIEWER):
Reference(s):
Personnel Contacted:
FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-06 ID Number: FSS-H1-1 Level of Significance: Suggestion Reviewer: RXV Capability Category: Met OBSERVATION:
BASIS FOR LEVEL OF SIGNIFICANCE:
Need to list where documents are located.
POSSIBLE RESOLUTION (REVIEWER):
Reference(s):
Personnel Contacted:
FPIP-0208 Scoping Fire Modeling Revision 2 Spreadsheets located in C:\\PRA\\HNP\\FPRA_FRANC HNP-M/MECH-1128 Hot Gas Layer Calculaitons HNP-M/MECH-1129 Fire Zone of Influence Calculation Att2(Source-Target).pdf Att3(FixedWalkdown).pdf Att4(TransientWalkdown).pdf
FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-06 ID Number: FSS-H8-1 Level of Significance: Finding Reviewer: RXV Capability Category: Not Met OBSERVATION:
No multi compartment fire scenarios were considered.
BASIS FOR LEVEL OF SIGNIFICANCE:
POSSIBLE RESOLUTION (REVIEWER):
Reference(s):
Personnel Contacted:
FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-06 ID Number: FSS-H9-1 Level of Significance: Summary Reviewer: RXV Capability Category: Not Met OBSERVATION:
No work on uncertainities was done BASIS FOR LEVEL OF SIGNIFICANCE:
POSSIBLE RESOLUTION (REVIEWER):
Reference(s):
Personnel Contacted:
IGNITION FREQUENCY ELEMENT This element estimates the frequency of fires (expressed as fire ignitions per reactor-year). Fire frequencies are ultimately estimated for each selected fire scenario (from the FSS element) and can be developed for a compartment as a whole, for a group of ignition sources, or for a specific individual ignition source depending on the nature of the fire scenario. The ignition frequency values are fed forward to the FQ element for incorporation into the final risk calculations.
HIGH LEVEL REQUIREMENTS FOR IGNITION FREQUENCY (IGN)
HLR HLR Description HLR Summary (From Review)
HLR-IGN-A The FPRA shall develop fire ignition frequencies for every physical analysis unit that has not been qualitatively screened.
All applicable supporting requirements for this HLR were met.
However, the ignition frequency data from NUREG/CR-6850 are in error because they are based on nuclear power history years rather than reactor year. This discrepancy is judged to be small in magnitude and result in slightly conservative frequencies. One finding was written to update the ignition frequencies when the NUREG/CR-6850 data are revised. Two suggestions were made:
Perform the review of plant-specific fire data and justify using (or not using) Bayesian updating of the generic fire frequencies; clarify documentation regarding whether locked high radiation areas were exempted from consideration of transient combustibles. Refer to F&O finding IGN-A5-1, and suggestions IGN-A4-1 and IGN-A9-1.
HLR-IGN-B The FPRA shall document the fire frequency estimation in a manner that facilitates FPRA applications, upgrades, and peer review.
All applicable supporting requirements for this HLR were met. One suggestion was made regarding improving the documentation to include a discussion of ignition frequency uncertainty. Refer to F&O suggestion IGN-B5-1.
SUPPORTING REQUIREMENTS FOR IGNITION FREQUENCY SR Level Observation Basis Cap Cat IGN-A1 Summary This SR is Met because the NUREG/CR-6850 ignition frequency data are used and these are based on nuclear power history for plants of similar type, characteristics, etc., as Harris. No datum was excluded. (Reference = HNP-F/PSA-0071)
Met IGN-A2 Other This SR is N/A because no datum outside the nuclear power industry was included.
N/A IGN-A3 Other This SR is N/A because no engineering judgment was required or employed.
N/A IGN-A4 Summary This SR is CC-I (No Requirement).
1 IGN-A4 Suggestion Perform the review of plant-specific fire data (or cite this if it has been performed) and justify why (and how) or why not Bayesian updating of the generic fire frequencies was performed.
F&O IGN-A4-1 IGN-A5 Summary This SR is Met because the NUREG/CR-6850 ignition frequency data are used and these are calculated on a reactor-year basis which includes weighting by the plant availabilities in the database. (Reference = HNP-F/PSA-0071)
But: refer to F&O IGN-A5-1 Met IGN-A5 Finding Need to update ignition frequency data once NUREG/CR-6850 is updated with the correct numbers based on reactor-year basis.
F&O IGN-A5-1 IGN-A6 Other This SR is N/A because no Bayesian updating for plant-specific fire history has been performed.
N/A IGN-A7 Summary This SR is Met because the NUREG/CR-6850 ignition source counting and frequency apportioning methods are used, as supplemented by NFPA-805 FAQs. (Reference
= HNP-F/PSA-0071, with Attachments) In addition, as per the Discussion, a calculation was performed (Ricky Davis) at the reviewer's request on whether the sum of ignition bin frequencies and physical analysis unit frequencies matched (i.e., "plant-wide fire frequency must be conserved," and this was confirmed).
Met IGN-A8 Summary This SR is CC-III because not only are greater-than-zero ignition frequencies assigned to every plant physical analysis unit, but also each potentially fire-risk-relevant ignition source has an assigned frequency. (Reference = HNP-F/PSA-0071, with Attachment 8) 3 IGN-A9 Summary This SR is Met, although there is a misleading statement in the documentation regarding postulation of transient combustibles in locked high radiation areas or very small rooms; see Met
SUPPORTING REQUIREMENTS FOR IGNITION FREQUENCY SR Level Observation Basis Cap Cat F&O IGN-A9-1.
IGN-A9 Suggestion Revise the misleading text so that it is clear that every compartment was assigned a transient fire frequency, with explanation of how administratively-controlled entities within such compartments were treated for the purpose of assigning transient.
F&O IGN-A9-1 IGN-A10 Summary This SR is CC-II because use of the NUREG/CR-6850 fire ignition frequencies carries with it fully characterized uncertainty distributions. (Reference = HNP-F/PSA-0071) 2 IGN-B1 Summary This SR is Met per the documentation in HNP-F/PSA-0071.
Met IGN-B2 Summary This SR is Met per the documentation in HNP-F/PSA-0071.
Met IGN-B3 Summary This SR is Met per the documentation in HNP-F/PSA-0071.
Met IGN-B4 Other This SR is N/A because plant-specific frequency updating was not performed.
N/A IGN-B5 Summary This SR is Met because the uncertainties associated with the NUREG/CR-6850 ignition frequency data automatically apply.
Met IGN-B5 Suggestion Include reference in HNP-F/PSA-0076 to the discussion of ignition frequency uncertanties in NUREG/CR-6850.
F&O IGN-B5-1
FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-06 ID Number: IGN-A4-1 Level of Significance: Suggestion Reviewer: RHG Capability Category: 1 OBSERVATION:
This SR is CC-I (No Requirement). The following discussion addresses the assumed intention to achieve CC-II or III. As stated in FPIP-0206, "plant specific fire events need to be collected so that it can be determined if the generic frequencies need to be specialized, i.e. Bayesian updated, to take into account plant experience. Two questions need to be answered: (1) Are there any unusual fire occurrence patterns at the plant? (2) Is the development of plant specific fire frequencies warranted given the answer to question (1). Plant fire events need to be collected If the answer to question (1) is that the plant has not experienced any fire patterns, then a Bayesian update of the generic frequencies is not necessary On the other hand, if the plant has experienced patterns of fire that stem from a common cause, these fires need to be investigated. If that common cause has been addressed and plant changes have taken place to address them, then generic frequencies are warranted If the plants events are already in the Fire Events DataBase, then, due to the nature of Bayesian statistics, the events for the plant that are already in the database can be ignored except for one case. If that fire or set of fires represent a pattern of fires due to a common or recurring cause, then the generic frequency for the applicable location(s) needs to be updated with the events not already in the Fire Events DataBase." There is no discussion whether a review of plant-specific fires was performed, although it has been confirmed by Harris PRA staff (Dave Miskiewicz) that no Bayesian updating of generic fire frequencies has been performed for plant-specific history. This implies that both of the questions above were answered NO. This confirmation, along with a listing of the plant-specific fire history (which was provided by Dave Miskiewicz to the reviewer) needs to be included in the appropriate documentation (presumably HNP-F/PSA-0071). It appears that the listing of plant-specific fire history (1988-present) appropriately captures potential candidate fires for Bayesian updating, if deemed necessary, to ensure a thorough review can be performed. Suggestion F&O IGN-A4-01 is to perform the review of plant-specific fire data (or cite this if it has been performed) and justify why (and how) or why not Bayesian updating of the generic fire frequencies was performed.
BASIS FOR LEVEL OF SIGNIFICANCE:
Suggestion F&O IGN-A4-01 is to perform the review of plant-specific fire data (or cite this if it has been performed) and justify why (and how) or why not Bayesian updating of the generic fire frequencies was performed.
FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-06 ID Number: IGN-A4-1 Level of Significance: Suggestion Reviewer: RHG Capability Category: 1 POSSIBLE RESOLUTION (REVIEWER):
Reference(s):
Personnel Contacted:
FPIP-0206 Dave Miskiewicz
FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-05 ID Number: IGN-A5-1 Level of Significance: Finding Reviewer: RHG Capability Category: Met OBSERVATION:
This SR is Met because the NUREG/CR-6850 ignition frequency data are used and these are calculated on a reactor-year basis which includes weighting by the plant availabilities in the database. (Reference = HNP-F/PSA-0071)
BASIS FOR LEVEL OF SIGNIFICANCE:
The following Note (3) from Table 4.5.1-2(c) of ASME RA-Sb-2005 under HLR-IE-C applies throughout HLR-IGN. Note that the IGN SRs for the Harris FPRA were not evaluated against this Note because this Note was not followed in developing the generic ignition frequencies in NUREG/CR-6850, the curently acceptable source for generic ignition frequencies. It is anticipated that NUREG/CR-6850 will correct their frequencies (either through the NFPA-805 FAQ process or another revision) to align with the Note. Nonetheless, Finding F&O HLR-IGN-01 (applicable to all related SRs under HLR-IGN) is to ensure compatibility with the requirement of Note (3) to Table 4.5.1.2© of ASME RA-Sb-2005 (HLR-IE-C) throughout HLR-IGN for the Harris FPRA. Here is the Note. "For the computation of average annual CDF/LERF the appropriate units for initiating event frequency are events per calendar year, commonly expressed as events per reactor-year, where a reactor-year is one full calendar of experience for one reactor." Additional detail as to how to perform the appropriate calculation can be found in the Note and should be considered part of Finding HLR-IGN-01.
POSSIBLE RESOLUTION (REVIEWER):
Reference(s):
Personnel Contacted:
HNP-F/PSA-0071
FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-05 ID Number: IGN-A9-1 Level of Significance: Suggestion Reviewer: RHG Capability Category: Met OBSERVATION:
This SR is Met, although there is a statement that "Transients were postulated in each compartment with the exception of those that were either locked high radiation areas or very small rooms where a transient fire is assumed to impact all targets" in the Fire PRA Notebook.
While the latter exclusion (small rooms where all targets were assumed to be impacted) may be acceptable (provided a non-zero fire ignition frequency was assigned to this area), the former exclusion for "locked high radiation areas" is not because the Standard requires that the possibility of transient combustible fires be postulated "regardless of administrative restrictions."
Based on subsequent discussion with Harris PRA staff (Beth Baucom and Mike Fletcher), the reviewers discovered that the statement regarding failure to postulate transients in "compartments... that were locked high radiation areas" was misleading. No high radiation area comprised an entire compartment - any such entity was always only part of a larger compartment (in effect a sub-compartment) such that there was always a transient postulated in each compartment. In fact, the floor area of the high radiation area was included with that of its enclosing compartment, such that it was implicitly assigned the same transient weighting factors as the rest of the compartment. Suggestion F&O IGN-A9-01 is to revise the misleading text so that it is clear that every compartment was assigned a transient fire frequency, with explanation of how administratively-controlled entities within such compartments were treated for the purpose of assigning transient weighting factors.
BASIS FOR LEVEL OF SIGNIFICANCE:
Suggestion F&O IGN-A9-01 is to revise the misleading text so that it is clear that every compartment was assigned a transient fire frequency, with explanation of how administratively-controlled entities within such compartments were treated for the purpose of assigning transient weighting factors.
POSSIBLE RESOLUTION (REVIEWER):
Reference(s):
Personnel Contacted:
HNP-F/PSA-0076 (FPRA Notebook)
Beth Baucom Mike Fletcher
FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-05 ID Number: IGN-B5-1 Level of Significance: Suggestion Reviewer: RHG Capability Category: Met OBSERVATION:
This SR is Met because the uncertainties associated with the NUREG/CR-6850 ignition frequency data automatically apply (although this should be mentioned in HNP-F/PSA-0071) and the following assumptions related to and sources of uncertainty in ignition frequencies are stated in HNP-F/PSA-0076 (FPRA Notebook): "Fire ignition frequencies remain constant over time; The likelihood of fire ignition is the same across an equipment type, regardless of size, usage level, working environment, etc." Suggestion F&O IGN-B5-01 is to include reference in HNP-F/PSA-0076 to the discussion of ignition frequency uncertanties in NUREG/CR-6850, including parametric values for the generic frequencies, that is found in FPIP-0206.
BASIS FOR LEVEL OF SIGNIFICANCE:
Suggestion F&O IGN-B5-01 is to include reference in HNP-F/PSA-0076 to the discussion of ignition frequency uncertanties in NUREG/CR-6850, including parametric values for the generic frequencies, that is found in FPIP-0206.
POSSIBLE RESOLUTION (REVIEWER):
Reference(s):
Personnel Contacted:
HNP-F/PSA-0076 (FPRA Notebook)
QUANTITATIVE SCREENING ELEMENT This element involves the screening of fire compartments based on their quantitative contribution to fire risk. [As with QLS, element QNS only considers physical analysis units as individual risk contributors. All physical analysis units are reconsidered as a part of the multi-compartment fire scenario analysis (see HLR-FSS-E).] Physical analysis units whose contribution to fire risk is shown to meet the quantitative screening criteria need not be analyzed in additional detail.
HIGH LEVEL REQUIREMENTS FOR QUANTITATIVE SCREENING (QNS)
HLR HLR Description HLR Summary (From Review)
HLR-QNS-A If quantitative screening is performed, the FPRA shall establish quantitative screening criteria to ensure the estimated cumulative impact of screened physical analysis units on CDF and LERF is small.
The licensee did not perform quantitative screening. This element is not applicable.
HLR-QNS-B If quantitative screening is performed, the FPRA shall identify those physical analysis units that screen out as individual risk contributors.
The licensee did not perform quantitative screening. This element is not applicable.
HLR-QNS-C VERIFY the cumulative impact of screened physical analysis units on CDF and LERF is small.
The licensee did not perform quantitative screening. This element is not applicable.
HLR-QNS-D The FPRA shall document the results of quantitative screening in a manner that facilitates FPRA applications, upgrades, and peer review The licensee did not perform quantitative screening. This element is not applicable.
CIRCUIT FAILURES ELEMENT This element refines that treatment of fire-induced cable failures and their impact on the plant equipment, systems, and functions included in the FPRA plant response model. This element also estimates the relative likelihood of various circuit failure modes such as loss of function failures versus spurious operation failures. Quantified circuit failure mode likelihood estimates are incorporated into the FPRA plant response model (developed under element PRM) as a part of CCDP and CLERP quantification in element FQ.
HIGH LEVEL REQUIREMENTS FOR CIRCUIT FAILURES (CF)
HLR HLR Description HLR Summary (From Review)
HLR-CF-A The FPRA shall determine the applicable conditional probability of the cable and circuit failure mode(s) that would cause equipment functional failure and/or undesired spurious operation based on the credited function of the equipment in the FPRA.
Based upon conversations with licensee staff, both supporting requirements for this HLR were met. However, the performance of these tasks was not documented. Two suggestions were made regarding documentation. Refer to F&O suggestions CF-A1-1 and CF-A2-1.
HLR-CF-B The FPRA shall document the development of the elements above in a manner that facilitates FPRA applications, upgrades, and peer review.
The supporting requirement for this HLR was not met due to lack of documentation of the tasks performed. Refer to F&O finding CF-B1-
- 1.
SUPPORTING REQUIREMENTS FOR CIRCUIT FAILURES SR Level Observation Basis Cap Cat CF-A1 Summary Based on discussions with licensee staff, Harris has identified cable failures and whether or not the mode is intra-cable or inter-cable. See F&O CF-A1-1 Met CF-A1 Suggestion Need to complete the analysis and incorporate the results into the appropriate document.
F&O CF-A1-1 CF-A2 Summary This SR is Met. By using the values from NUREG/CR-6850, the associated uncertainties are assumed to apply. See F&O CF-A2-1 Met CF-A2 Suggestion Directly include uncertainty values into the documentation.
F&O CF-A2-1 CF-B1 Summary This SR is Not Met because the material discussed in SRs CF-A1 and A2 has not yet been incorporated into the documentation.
Not Met CF-B1 Finding Incorporate the material discussed in SRs CF-A1 and A2 into the documentation.
F&O CF-B1-1
FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-04 ID Number: CF-A1-1 Level of Significance: Suggestion Reviewer: RHG Capability Category: Met OBSERVATION:
This SR is Met. Per discussion with Harris PRA staff (Beth Baucom and Dave Miskiewicz), as a supplement to the draft material in Table 10-1 of HNP-F/PSA-0076 (FPRA Notebook), Harris has identified cable failures and whether or not the mode is intracable or intercable.
Furthermore, the maximum best estimate probabilities from NUREG/CR-6850 Table 10-1 through 10-4 (0.6 for intracable without CPT, 0.3 for intracable or intercable with CPT) have been assumed). What remains is to complete this analysis and incorporate into the appropriate document (likely HNP-F/PSA-0079). Suggestion F&O CF-A1-01 cites the need to complete the analysis and incorporate the results into the appropriate document.
BASIS FOR LEVEL OF SIGNIFICANCE:
Suggestion F&O CF-A1-01 cites the need to complete the analysis and incorporate the results into the appropriate document.
POSSIBLE RESOLUTION (REVIEWER):
Reference(s):
Personnel Contacted:
HNP-F/PSA-0076, Table 10-1 independent calculation (as per Harris staff)
NUREG/CR-6850 Beth Baucom Dave Miskiewicz
FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-04 ID Number: CF-A2-1 Level of Significance: Suggestion Reviewer: RHG Capability Category: Met OBSERVATION:
This SR is Met. By using the values from NUREG/CR-6850, the associated uncertainties are assumed to apply (see Tables 10-1 through 10-4). Suggestion F&O CF-A2-01 is to directly include these uncertainty values into the documentation.
BASIS FOR LEVEL OF SIGNIFICANCE:
Suggestion F&O CF-A2-01 is to directly include these uncertainty values into the documentation.
POSSIBLE RESOLUTION (REVIEWER):
Reference(s):
Personnel Contacted:
NUREG/CR-6850 Beth Baucom Dave Miskiewicz
FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-04 ID Number: CF-B1-1 Level of Significance: Finding Reviewer: RHG Capability Category: Not Met OBSERVATION:
This SR is Not Met because the material discussed in SRs CF-A1 and A2 has not yet been incorporated into the documentation. Finding F&O CF-B1-01 is to incorporate this material.
BASIS FOR LEVEL OF SIGNIFICANCE:
Finding F&O CF-B1-01 is to incorporate this material.
POSSIBLE RESOLUTION (REVIEWER):
Reference(s):
Personnel Contacted:
HUMAN RELIABILITY ANALYSIS ELEMENT This element considers operator actions as called out in the relevant plant fire response procedures. It also includes the identification of human failure events (HFEs) for inclusion in the FPRA plant response model. The HRA element also includes the quantification of human error probabilities (HEPs) for the modeled actions which are fed forward to element FQ in support of the CCDP and CLERP calculations for each selected fire scenario from element FSS.
HIGH LEVEL REQUIREMENTS FOR HUMAN RELIABILITY ANALYSIS (HRA)
HLR HLR Description HLR Summary (From Review)
HLR-HRA-A The FPRA shall identify human actions relevant to the sequences in the FPRA plant response model.
Both supporting requirements for this HLR were met. One suggestion was made to ensure that HLR-E3 and HLR-E4 are met if shutdown actions are added to the model in the future. Refer to F&O suggestion HRA-A2-1.
HLR-HRA-B The FPRA shall include events where appropriate in the FPRA that represent the impacts of incorrect human responses associated with the identified human actions.
Two supporting requirements were not met for this HLR. The first involves not modeling any fire response operator actions, neither the beneficial nor adverse effects. The second involves failure to model operator errors based on instrument unavailability due to fire. A suggestion was made to confirm the time available for key human actions that would not be affected by the fire. Refer to F&O findings HRA-B2-1 and HRA-B3-1, and suggestion HRA-B1-1.
HLR-HRA-C The FPRA shall quantify HEPs associated with the incorrect responses accounting for the plant-specific and scenario-specific influences on human performance, particularly including the effects of fires.
The nine supporting requirements for this HLR are from the internal events portion of the standard and are incorporated by reference. All supporting requirements were met except for supporting requirement HR-G6, which involves checking post-initiating event human error probabilities for reasonableness relative to each other in the context of the various scenarios. This could not be assessed because the Harris fire PRA has not been completed. There were four findings associated with this HLR.
One is that the detailed analysis approach does not conform to the standard definition of significant for capability category II. Another involves availability of instrumentation. The third has to do with whether event timing is influenced by the fire. The final finding is associated with HR-G6, discussed above. Refer to F&O findings HRA-C1-3, HRA-C1-4, HRA-C1-5, and HRA-C1-6.
There were three suggestions associated with this HLR. One involves use of the simplified screening method for modifying internal events human error probabilities. A second suggests basing the changed HEP on the time when the cues needed to make the decision would occur, rather than the time window. The final suggestion relates to assigning a lower bound for combinations of three or more HFEs in combination. Refer to F&O suggestions HRA-C1-1, HRA-C1-2, and HRA-C1-7.
HIGH LEVEL REQUIREMENTS FOR HUMAN RELIABILITY ANALYSIS (HRA)
HLR HLR Description HLR Summary (From Review)
HLR-HRA-D The FPRA shall include recovery actions only if it has been demonstrated that the action is plausible and feasible for those scenarios to which it applies, particularly accounting for the effects of fires.
This HLR was not applicable; fire recovery actions were not included in the Harris fire PRA model. However, if such actions are incorporated at a later date, the licensee should ensure that supporting requirement HRA-D1, and the supporting requirements associated with internal events PRA standard HLR-HR-H are met. Refer to F&O suggestion HRA-D1-1.
HLR-HRA-E The FPRA shall document the HRA, including the unique fire-related influences of the analysis, in a manner that facilitates FPRA applications, upgrades, and peer review.
The supporting requirements for this HLR were met.
SUPPORTING REQUIREMENTS FOR HUMAN RELIABILITY ANALYSIS SR Level Observation Basis Cap Cat HRA-A1 Summary Section 6 of Harris calculation HNP-F/PSA-0075 states that all HFEs from the internal event model are included in the fire PRA.
Met HRA-A2 Summary The safe shutdown actions have been identified, and HLR-E 1 and E2 are met - see Attachment 6 to HNP-F/PSA-0075 for the list of actions.
Met HRA-A2 Suggestion Ensure that HLR-E3 and HLR-E4 are met if shutdown actions are added to the model in the future.
F&O HRA-A2-1 HRA-B1 Summary None of this definition is changed from the internal events PRA Met HRA-B1 Suggestion Confirm that the time available for key human actions would not be affected by any fire effects, including spurious actions.
F&O HRA-B1-1 F&O HRA-C1-5 HRA-B2 Summary No new fire-related safe shutdown HFEs were included in the fire PRA, even though some were determined to have negative consequences.
Not Met HRA-B2 Finding PRA needs to reflect potential adverse consequences of operator actions taken per the fire response procedures.
F&O HRA-B2-1 HRA-B3 Finding Need to model operator errors based on instrument unavailability due to fire.
F&O HRA-B3-1 Not Met HRA-C1 Summary Part 2 HLR-HR-G is incorporated by reference.
All supporting requirements were addressed, and one (HR-G6) was not met.
Not Met HRA-C1 Suggestion (HR-G1) Review use of the simplified screening method for modifying the internal events HEPs for local actions and for control room actions.
F&O HRA-C1-1 HRA-C1 Suggestion (HR-G3) Consider basing the timing on the time when the cues needed to make the decision would occur, rather than the time window.
F&O HRA-C1-2 HRA-C1 Finding (HR-G1) The approach to determining which HEPs are developed using a detailed analysis does not conform to the standard definition of significant for capability category II.
F&O HRA-C1-3 1
HRA-C1 Finding (HR-G3) Need to address the availability of instrumentation as one of the factors considered in determining the HEPs, both in the simplified screening method and the detailed method.
F&O HRA-C1-4 1
HRA-C1 Finding (HR-B4) Need to determine whether event timing is influenced by the fire, rather than assuming that T-H analysis based on the accident sequence is unaffected by the initiator being a fire.
F&O HRA-C1-5 Met HRA-C1 Finding (HR-G6) Check post-initiating event human error probabilities for reasonableness relative to each other in the context of the various scenarios.
F&O HRA-C1-6 Not Met HRA-C1 Suggestion (HR-G7) Need to apply the recommended lower bound (1E-05) to combinations of three or more HFEs in combination, or justify the use of a lower F&O HRA-C1-7
SUPPORTING REQUIREMENTS FOR HUMAN RELIABILITY ANALYSIS SR Level Observation Basis Cap Cat bound (1E-06 was used).
HRA-D1 Suggestion This HLR was not applicable; fire recovery actions were not included in the Harris fire PRA model. However, if such actions are incorporated at a later date, this would become applicable.
F&O HRA-D1-1 N/A HRA-E1 Summary The documentation is consistent with the level of detail of the analysis; the detailed analyses are consistent with those of the internal events analysis.
Met
FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-04 ID Number: HRA-A2-1 Level of Significance: Suggestion Reviewer: GWP Capability Category: Met OBSERVATION:
The safe shutdown actions have been identified, and HLR-E 1 and E2 are met - see Attachment 6 to HNP-F/PSA-0075 for the list of actions. There is no evidence that HLR-E3 and E4 have been met. However, since none of these actions was included in the Fire PRA, it is somewhat moot.
BASIS FOR LEVEL OF SIGNIFICANCE:
Low significance since no actions are accounted for. If shutdown actions are included in the model in future HLR-E3 and 4 should be addressed.
POSSIBLE RESOLUTION (REVIEWER):
Reference(s):
Personnel Contacted:
Calc file HNP-F/PSA-0075
FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-04 ID Number: HRA-B1-1 Level of Significance: Suggestion Reviewer: GWP Capability Category: Met OBSERVATION:
None of this definition is changed from the internal events PRA BASIS FOR LEVEL OF SIGNIFICANCE:
Confirm that the time available for key human actions would not be affected by any fire effects, including spurious actions. See comment under HRA-C1, HR-G4.
POSSIBLE RESOLUTION (REVIEWER):
Reference(s):
Personnel Contacted:
Calc file HNP-F/PSA-0075
FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-04 ID Number: HRA-B2-1 Level of Significance: Finding Reviewer: GWP Capability Category: Not Met OBSERVATION:
No new fire-related safe shutdown HFEs were included in the fire PRA, even though some were determined to have negative consequences. This is acceptable if the corresponding actions are removed from the fire response procedures, and the PRA is intended to model the plant using these modified procedures. However, it is not clear at this time what is ultimately intended. If the actions which would disable plant equipment are retained, then the PRA needs to reflect the negative consequences, even if the positive aspects of the actions are not credited.
BASIS FOR LEVEL OF SIGNIFICANCE:
Finding since the inclusion of negative effects could negatively impact risk.
POSSIBLE RESOLUTION (REVIEWER):
Reference(s):
Personnel Contacted:
Calc file HNP-F/PSA-0075
FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-04 ID Number: HRA-B3-1 Level of Significance: Finding Reviewer: GWP Capability Category: Not Met OBSERVATION:
Section 7.3 states that no additions were made to the fire PRA model to model equipment failure due directly to operator response from a faulty indications, due to redundant indication being always available, and opertator training reinforces checking redundant and diverse indications prior to initiating a response.
to PSA-0077 lists the annunciators associated with shutting down equipment.
However, there is no discussion of the routing of the cables, so there is no validation that at least one of the identified instruments is available for a given fire. Further, there is no discussion as to how the operator would deal with conflicting indications, which is identified as the specific concern for this element of the standard.
Furthermore, this scope may not be sufficient to address HR-B3, since this should include cases where, for example, spurious indications of valve closure could lead to shutting pumps off, without necessarily causing a specific alarm evaluated in Attachment 7.
BASIS FOR LEVEL OF SIGNIFICANCE:
POSSIBLE RESOLUTION (REVIEWER):
Provide a demonstration that the instruments are routed and protected, and/or the protocol for dealing with conflicting annunciators and instrumentation. Also identify those other indications that could lead the operator to secure a system or train which may not cause the specific alarms evaluated on Attachment 7.
Reference(s):
Personnel Contacted:
Calc file HNP-F/PSA-0075 Calc file HNP-F/PSA -0077, attachment 7
FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-04 ID Number: HRA-B3-1 Level of Significance: Finding Reviewer: GWP Capability Category: Not Met FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-05 ID Number: HRA-C1-1 Level of Significance: Suggestion Reviewer: AJH Capability Category:
OBSERVATION:
The simplified screening method identifies how the internal events HEPs are modified for local actions and for control room actions. Some anomalies were noted in the application of this method:
OPER-20 is set to 1.0 as a local action. The HEP assumes that seal injection is unavailable, and evaluates local action to slowly restore CCW to the RCP thermal barrier cooler. This action would not be consistent with Westinghouse recommendations for loss of RCP seal cooling, which would require a plant cooldown without restoration of cooling flow. If seal injection is available at the time OPER-20 applies, then it would not be a local action.
OPER-3 is doubled rather than multiplied by a factor of 10, indicating that feed and bleed is always initiated after the fire is out. No basis for this assumption is provided.
OPER-32 is an ATWS dependency of 0.5, but it is doubled to 1.0 which is unnecessary.
BASIS FOR LEVEL OF SIGNIFICANCE:
POSSIBLE RESOLUTION (REVIEWER):
Reference(s):
Personnel Contacted:
FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-07 ID Number: HRA-C1-2 Level of Significance: Suggestion Reviewer: GWP Capability Category:
OBSERVATION:
The HRA screening approach is based on three factors: whether the action is ex-control room or not, whether the instrumentation is available, and on the timing of the action. The timing is based on the total time for completion of the action. Basing the change in HEP on timing is presumably a surrogate for the additional stress resulting from the fire effects. Since the increased stress will certainly be a factor during the cognitive phase, it would perhaps be better to base the timing on the time when the cues needed to make the decision would occur, rather than the time window. For example, this would change the screening value for OPER-3 by a factor of 10 rather than 2.
BASIS FOR LEVEL OF SIGNIFICANCE:
POSSIBLE RESOLUTION (REVIEWER):
Reference(s):
Personnel Contacted:
FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-04 ID Number: HRA-C1-3 Level of Significance: Finding Reviewer: GWP Capability Category: 1 OBSERVATION:
HR-G1 as incorporated by reference: The approach to determining which HEPs are developed using a detailed analysis does not conform to the standard definition of significant for capability category II. Given the fact that the model is still in development, this is understandable.
BASIS FOR LEVEL OF SIGNIFICANCE:
POSSIBLE RESOLUTION (REVIEWER):
When the model is more stable, if a Capability Category II is required, the significant HEPs as defined in the standard will need to be analyzed in detail.
Reference(s):
Personnel Contacted:
Calc file HNP-F/PSA-0075 Spreadsheet file hfe_cp.xls Ricardo Davis-Zapata
FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-04 ID Number: HRA-C1-4 Level of Significance: Finding Reviewer: GWP Capability Category: 1 OBSERVATION:
HR-G3 incorporated by reference: The majority of the HEPs are evaluated by the simplified screening method, and six are analyzed using by modifying the internal events HEP evaluations. While the instruments required have been identified, to date no cable tracing has been documented as being performed. Availability of insrumentation is one of the factors considered in determining the HEPs, both in the simplified screening method and the detailed method. However in both cases it is simply assumed to be available. In fact in Section 4.3, it is stated that the instrumentation is assumed to be available. To achieve Capability Category II, this would have to be verified, and where there is a possibility of conflicting indication, how this affects the HEPs needs to be documented and incorporated into the HEP calculations. While this verification is identified as currently in progress, the documentation does not describe how conflicting indications will be dispositioned in the HEP calculations.
BASIS FOR LEVEL OF SIGNIFICANCE:
POSSIBLE RESOLUTION (REVIEWER):
Document the method and basis for accounting of conflicting indications in the calculation of HEPs, and complete cable route verifications.
Reference(s):
Personnel Contacted:
Calc file HNP-F/PSA-0075
FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-04 ID Number: HRA-C1-5 Level of Significance: Finding Reviewer: GWP Capability Category: Met OBSERVATION:
HR-G4 is incorporated by reference: Section 7.1.3, detailed HRA analysis, states that the event timing was generally driven by T-H analysis based on the accident sequence and was unaffected by the initiator being a fire. While this may be generally true, it is possible that a fire caused problem, e.g., spurious iclosure of a valve used in the suction path of many injection paths may need quick detection and response by the crew (example from NUREG/CR-6850, page 12-15). It is not clear if this is an important issue.
BASIS FOR LEVEL OF SIGNIFICANCE:
This is probably not a significant issue, but could have an impact on some sequences.
POSSIBLE RESOLUTION (REVIEWER):
Reference(s):
Personnel Contacted:
Calc file HNP-F/PSA-0075
FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-04 ID Number: HRA-C1-6 Level of Significance: Finding Reviewer: GWP Capability Category: Not Met OBSERVATION:
HR-G6 as incorporated by reference: It is too early in the process for this supporting requirement to have been achieved satisfactorily, since only a few HFEs have been developed in detail.
BASIS FOR LEVEL OF SIGNIFICANCE:
POSSIBLE RESOLUTION (REVIEWER):
When a more complete set of detailed HEP evaluations are available, check for consistency of the HEP quantification per this SR.
Reference(s):
Personnel Contacted:
Calc file HNP-F/PSA-0075
FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-05 ID Number: HRA-C1-7 Level of Significance: Suggestion Reviewer: GWP Capability Category:
OBSERVATION:
The documentation states that "for combinations of three or more HFEs, a lower bound of 1E-06 was used. This lower bound was decreased to account for the fact that many of the third and fourth HFEs are actions that occur many hours after the initiating event and... " While this may be true for the majority of cases, those cases for which this is not true should use the 1E-05 limit.
BASIS FOR LEVEL OF SIGNIFICANCE:
POSSIBLE RESOLUTION (REVIEWER):
Reference(s):
Personnel Contacted:
HNP-F/PSA-0075
FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-05 ID Number: HRA-D1-1 Level of Significance: Suggestion Reviewer: GWP Capability Category: N/A OBSERVATION:
This HLR was not applicable; fire recovery actions were not included in the Harris fire PRA model. However, if such actions are incorporated at a later date, the licensee should ensure that supporting requirement HRA-D1, and the supporting requirements associated with internal events PRA standard HLR-HR-H are met.
BASIS FOR LEVEL OF SIGNIFICANCE:
POSSIBLE RESOLUTION (REVIEWER):
Reference(s):
Personnel Contacted:
SEISMIC FIRE ELEMENT This element involves a qualitative review of potential interactions between an earthquake and fire that might contribute to plant risk.
This element does not include quantitative estimates of the risk associated with such interactions, but rather, seeks to ensure that such interactions have been considered and that steps are taken to ensure that the potential risk contributions are not significant.
HIGH LEVEL REQUIREMENTS FOR SEISMIC FIRE (SF)
HLR HLR Description HLR Summary (From Review)
HLR-SF-A The FPRA shall include a qualitative assessment of potential seismic-fire interaction issues in the FPRA.
The licensee provided a sparse and incomplete write-up on seismic-fire interactions. This area was not reviewed because it has not been performed by the licensee. Refer to F&O finding SF-A1-1.
HLR-SF-B The FPRA shall document the results of the seismic-fire interaction assessment in a manner that facilitates FPRA applications, upgrades, and peer review.
See HLR-SF-A
FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-07 ID Number: SF-1 Level of Significance: Finding Reviewer: PWL Capability Category: Not Met OBSERVATION:
Perform the tasks associated with fire PRA standard element SF and document. Self-assess to HLRs SS-A and SS-B and the associated supporting requirements. Have the completed work peer reviewed per the fire PRA standard requirements.
BASIS FOR LEVEL OF SIGNIFICANCE:
POSSIBLE RESOLUTION (REVIEWER):
Reference(s):
Personnel Contacted:
- 100 -
FIRE RISK QUANTIFICATION ELEMENT This element involves the quantification and presentation of fire risk results. In this element the FPRA plant response model (developed under element PRM), modified to include additional HFEs as identified in the HRA, is exercised for each fire scenario (as defined in element FSS). CCDP and CLERP values are calculated based on translation of the cable and equipment failures for each scenario, including specification of the failure modes, into PRM basic events, quantitative equipment failure mode values (from element CF), and HEP values (from element HRA). Final quantification mathematically combines the calculated CCDP/CLERP values with the corresponding fire frequency (IGN) and the conditional probability of fire damage (potentially including both a severity factor and non-suppression probability (FSS)) to yield estimates of fire risk in the form of CDF and LERF.
HIGH LEVEL REQUIREMENTS FOR FIRE RISK QUANTIFICATION (FQ)
HLR HLR Description HLR Summary (From Review)
HLR-FQ-A Quantification of the FPRA shall quantify the fire-induced CDF.
All supporting requirements for this HLR were met except for FQ-A4, which incorporates the QU-A supporting requirements from the internal events portion of the standard. Specifically, QU-A2a was not met, because the fire quantification method used at Harris does not identify individual sequences to support identification of significant accident sequences. Refer to F&O finding FQ-A4-1.
HLR-FQ-B The fire-induced CDF quantification shall use appropriate models and codes, and shall account for method specific limitations and features.
This HLR incorporates the QU-B supporting requirements from the internal events portion of the standard. All supporting requirements for this HLR were met.
HLR-FQ-C Model quantification shall determine that all identified dependencies are addressed appropriately.
This HLR incorporates the QU-C supporting requirements from the internal events portion of the standard. All supporting requirements for this HLR were met.
HLR-FQ-D The frequency of different containment failure modes leading to a fire-induced large early release shall be quantified and aggregated thus determining the fire-induced LERF.
This HLR, which incorporates the LE-E supporting requirements from the internal events portion of the standard, was not met because the licensee has not performed a LERF assessment.
Refer to F&O finding FQ-D1-1.
HLR-FQ-E The fire-induced CDF and LERF quantification results shall be reviewed and significant contributors to CDF and LERF, such as fires and their corresponding plant initiating events, fire locations, accident sequences, basic events (equipment unavailabilities and human failure events),
plant damage states, containment challenges and failure modes, shall be identified. The results shall be traceable This HLR, which incorporates the QU-D and LE-F supporting requirements from the internal events portion of the standard, was not met. There were two findings. The first finding involves the inability to determine significant basic events and sequences. The second finding relates to the definition of significant contributor.
Refer to F&O findings FQ-E1-1 and FQ-E1-2.
- 101 -
HIGH LEVEL REQUIREMENTS FOR FIRE RISK QUANTIFICATION (FQ)
HLR HLR Description HLR Summary (From Review) to the inputs and assumptions made in the FPRA.
HLR-FQ-F The CDF and LERF analyses shall be documented consistent with the applicable SRs.
This HLR, which incorporates the QU-F and LE-G supporting requirements from the internal events portion of the standard, was not met. There were four findings. The first finding is that several of the documentation requirements in QU-F2 are not in place. The second finding is that there is no documentation of the significant contributors to fire CDF. The third is that the assumptions and sources of uncertainty are not documented. The final finding is that no basis was provided to support any claim of non-applicability of any of the requirements incorporated by reference. Refer to F&O findings FQ-F1-1, FQ-F1-2, FQ-F1-3 and FQ-F2-1.
- 102 -
SUPPORTING REQUIREMENTS FOR FIRE RISK QUANTIFICAITON SR Level Observation Basis Cap Cat FQ-A1 Summary There is a clear link between components and required cables and the PRA basic events, and the association of applicable fire sources and targets in the plant. The quantification is complete in that each source is addressed, and the database queries which generate the quantification files (i.e.,
the PRA basic events assumed failed) appear to be correct.
Met FQ-A2 Summary Each fire scenario is quantified using a fire initiating event, which is evaluated using the transient - loss of decay heat removal and the transient-induced LOCA event tree logic. Fires which could cause another initiator (such as loss of feedwater or loss of offsite power for example) are effectively addressed by the target cables in the mitigating systems fault tree logic. The fire event also addresses interfacing-systems LOCA logic, including fire-induced ISLOCAs.
Met FQ-A3 Summary The quantification included the specific elements identified.
Met FQ-A4 Finding QU-A2a was not met; therefore this SR is also not met. Need to identify individual sequences to support identification of significant accident sequences F&O FQ-A4-1 Not Met FQ-A4 Summary QU-A2b - Only point estimates are calculated from the CAFTA model quantification of the CCDP, and from the Excel calculation of CDF.
1 FQ-A4 Summary Other QU-A SRs are either met or do not apply to the fire PRA.
FQ-B1 Summary All SRs from QU-B are met or not applicable; none of the SRs differentiate capability category.
Met FQ-C1 Summary All SRs from QU-C are met or not applicable; none of the SRs differentiate capability category.
Met FQ-D1 Finding LERF is not mentioned in the quantification calculation HNP-F/PSA-0079 Rev. 0. The fire PRA summary specifically excludes calculation of LERF from the scope of the fire PRA model.
FQ-D1-1 Not Met FQ-E1 Finding Significant contributors and significant basic events to fire LERF have not been determined. Also, Harris does not appear to use the definition as provided in the PRA standard.
FQ-E1-1 FQ-E1-2 Not Met FQ-F1 Summary Many SRs from QU-F are not met; none of the SRs for LE-G can be met since LERF is not addressed.
Not Met FQ-F1 Finding QU-F2 - Several of the recommended documentation requirements are not in place, specifically items b, e, f, g, i, j, m.
FQ-F1-1 FQ-F1 Finding QU-F3 - There is currenty no record of significant contributors to fire CDF.
FQ-F1-2 FQ-F1 Finding QU-F4 - Assumptions and sources of uncertainty FQ-F1-3
- 103 -
SUPPORTING REQUIREMENTS FOR FIRE RISK QUANTIFICAITON SR Level Observation Basis Cap Cat are not documented.
FQ-F2 Finding Harris has not assessed the fire PRA to the standard, and has therefore not determined whether any of the referenced internal events requirements are not applicable or provided bases if appropriate.
FQ-F2-1 Not Met
- 104 -
FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-06 ID Number: FQ-A4-1 Level of Significance: Finding Reviewer: AJH Capability Category: Not Met OBSERVATION:
QU-A2a - the fire quantification method does not identify individual sequences to support identification of significant accident sequences. Each fire initiator (source) is a separate number, with a supporting cutset file for the conditional CDP. The specific sequence is not identified in the cutset file for each cutset. Since the initiating event frequency, suppression credit, and details of the fire two-point modeling is addressed in each individual sheet, aggregation of the plant fire PRA results to evaluate significant sequences would be cumbersome, and has not been done.
BASIS FOR LEVEL OF SIGNIFICANCE:
POSSIBLE RESOLUTION (REVIEWER):
Reference(s):
Personnel Contacted:
- 105 -
FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-05 ID Number: FQ-D1-1 Level of Significance: Finding Reviewer: SAL Capability Category: Not Met OBSERVATION:
LERF is not mentioned in the quantification calculation HNP-F/PSA-0079 Rev. 0. The fire PRA summary specifically excludes calculation of LERF from the scope of the fire PRA model.
BASIS FOR LEVEL OF SIGNIFICANCE:
ASME standard includes LERF. NFPA-805 requires estimate of both CDF and LERF (paragraph 2.4.3.1).
POSSIBLE RESOLUTION (REVIEWER):
Reference(s):
Personnel Contacted:
HNP-F/PSA-0079 Rev. 0 (unapproved)
HNP-F/PSA-0076 R0
- 106 -
FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-06 ID Number: FQ-E1-1 Level of Significance: Finding Reviewer: SAL Capability Category: Not Met OBSERVATION:
LERF not calculated, so significant contributors and significant basic events to fire LERF have not been determined. Component and equipment importances cannot be determined effectively at this stage in the FPRA model development. A number of fire scenarios have CCDP = 1.0.
Cutset files are "subsumed" to remove non-minimal events, leaving behind a representative cutset file that may not include all equipment actually failed by the fire.
BASIS FOR LEVEL OF SIGNIFICANCE:
POSSIBLE RESOLUTION (REVIEWER):
Reference(s):
Personnel Contacted:
HNP-F/PSA-0079 Rev. 0 (unapproved)
- 107 -
FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-06 ID Number: FQ-E1-2 Level of Significance: Finding Reviewer: SAL Capability Category: Not Met OBSERVATION:
The definition of significant contributor in the PRA standard includes the idea of summing, in rank order, the fire sequences and considering any in the top 95%, or any that individually contribute 1% or more, as significant. This determination has not been made for fire CDF or LERF. Harris does not appear to use the definition as provided in the PRA standard.
BASIS FOR LEVEL OF SIGNIFICANCE:
POSSIBLE RESOLUTION (REVIEWER):
Reference(s):
Personnel Contacted:
HNP-F/PSA-0079 Rev. 0 (unapproved)
- 108 -
FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-06 ID Number: FQ-F1-1 Level of Significance: Finding Reviewer: AJH Capability Category: Not Met OBSERVATION:
QU-F2 - Several of the recommended documentation requirements are not in place, specifically items b, e, f, g, i, j, m.
BASIS FOR LEVEL OF SIGNIFICANCE:
POSSIBLE RESOLUTION (REVIEWER):
Reference(s):
Personnel Contacted:
- 109 -
FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-06 ID Number: FQ-F1-2 Level of Significance: Finding Reviewer: AJH Capability Category: Not Met OBSERVATION:
QU-F3 - There is currenty no record of significant contributors to fire CDF.
BASIS FOR LEVEL OF SIGNIFICANCE:
POSSIBLE RESOLUTION (REVIEWER):
Reference(s):
Personnel Contacted:
- 110 -
FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-06 ID Number: FQ-F1-3 Level of Significance: Finding Reviewer: SAL Capability Category:
OBSERVATION:
QU-F4 - Assumptions and sources of uncertainty are not documented.
BASIS FOR LEVEL OF SIGNIFICANCE:
POSSIBLE RESOLUTION (REVIEWER):
Reference(s):
Personnel Contacted:
- 111 -
FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-06 ID Number: FQ-F2-1 Level of Significance: Finding Reviewer: SAL Capability Category: Not Met OBSERVATION:
Harris has not assessed the fire PRA to the standard, and has therefore not determined whether any of the referenced internal events requirements are not applicable or provided bases if appropriate.
BASIS FOR LEVEL OF SIGNIFICANCE:
POSSIBLE RESOLUTION (REVIEWER):
Reference(s):
Personnel Contacted:
- 112 -
UNCERTAINTY AND SENSITIVITY ANALYSIS ELEMENT This element involves the identification and treatment of uncertainties throughout the FPRA process.
HIGH LEVEL REQUIREMENT FOR UNCERTAINTY AND SENSITIVITY ANALYSIS (UNC)
HLR HLR Description HLR Summary (From Review)
HLR-UNC-A The FPRA shall identify key sources of CDF and LERF uncertainties, including key assumptions and modeling approximations. These uncertainties shall be characterized such that their impacts on the results are understood.
The licensee has not addressed uncertainty. The applicable document has a list of twenty items, which includes some items not addressed completely, some items that are in the nature of identifications of conservatisms, and some things not addressed in the model. However, there is no treatment of uncertainty. This area was not reviewed because it has not been performed by the licensee. Refer to F&O finding UNC-1.
- 113 -
FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-07 ID Number: UNC-1 Level of Significance: Finding Reviewer: PWL Capability Category: Not Met OBSERVATION:
Perform the tasks associated with fire PRA standard element UNC and document. Self-assess to HLRs UNC-A and the associated supporting requirements. Have the completed work peer reviewed per the fire PRA standard requirements.
BASIS FOR LEVEL OF SIGNIFICANCE:
POSSIBLE RESOLUTION (REVIEWER):
Reference(s):
Personnel Contacted:
- 114 -
PRA CONFIGURATION CONTROL AND MODEL UPDATE (required by the standard in Section 1-5, but not called out as an element)
HIGH LEVEL REQUIREMENTS FOR PRA CONFIGURATION CONTROL/MODEL UPDATE (MUD)
HLR HLR Description HLR Summary (From Review)
HLR-MUD-A A process for monitoring FPRA inputs and collecting new information This requirement was met. Two suggestions were made. The first is to provide direction for monitoring industry-wide operational history. The second is to add the requirement to monitor updated or new methods. Refer to F&O suggestions MUD-A1-1 and MUD-A3-1.
HLR-MUD-B A process that maintains and upgrades the FPRA to be consistent with the as-built, as operated plant This requirement was not met in several respects. The Harris configuration control procedures do not reference the fire PRA standard or the supporting requirements therein. Also, the version of Regulatory Guide 1.200 which is expected to endorse, potentially with exceptions, the Standard for PRA for Nuclear Power Plant Applications, i.e., the combined standard which includes the fire PRA part, should be referenced once it is completed and is issued.
Refer to F&O finding MUD-B4-1.
HLR-MUD-C A process that ensures that the cumulative impact of pending changes is considered when applying the FPRA This requirement was met.
HLR-MUD-D A process that evaluates the impact of changes on previously implemented risk-informed decisions that have used the FPRA This requirement was met. One requirement that is currently in the standard, to assess past risk-informed applications when the PRA model is updated or upgraded, is slated for removal from the PRA standard in a future revision. The Harris configuration control procedure does not include such a requirement, but this was not considered a finding due to the anticipated standard revision.
HLR-MUD-E A process that maintains configuration control of computer codes used to support FPRA quantification This requirement was met.
HLR-MUD-F Documentation of the Program This requirement was met.
- 115 -
SUPPORTING REQUIREMENTS FOR CONFIGURATION CONTROL/MODEL UPDATE SR Level Observation Basis Cap Cat MUD-A1 Suggestion Provide direction in process to monitor industry wide operational history. Ensure that component data (generic and plant-specific) includes active fire protection systems, e.g.
fixed suppression, dampers.
MUD-A1-1 Met MUD-A2 Summary Based on review of licensee procedure ADM-NGGC-0004 Met MUD-A3 Suggestion Add language to monitor updated or new methodologies as appropriate.
MUD-A3-1 Met MUD-B1 Summary Based on review of licensee procedure ADM-NGGC-0004 Met MUD-B2 Summary Based on review of licensee procedure ADM-NGGC-0004 Met MUD-B3 Summary Based on review of licensee procedure ADM-NGGC-0004 Met MUD-B4 Finding Since fire standard not referenced, those SRs are not evaluated. Fire standard needs to be referenced in 9.2.5; currently only ASME Internal Events. Add latest reference to R.G.
1.200, which is expected to endorse the fire standard.
F&O MUD-B4-1 Not Met MUD-B5 Finding See above finding regarding lack of reference of fire standard.
F&O MUD-B4-1 Not Met MUD-B6 Finding See above finding on lack of reference of fire standard Note that peer reviews of the revised PSA model as determined by the PSA supervisor are prescribed F&O MUD-B4-1 Not Met MUD-C1 Summary Based on review of licensee procedure ADM-NGGC-0004 Met MUD-D1 Summary Impact on previously implemented decisions not performed except for required programs such as A-4, ISI, MSPI, TS 4B etc. `Not performed on past decisions such as one time AOT or other license amendment. It should be noted that the impact on other ongoing analyses and applications is assessed. This is not a finding because this portion of the requirement is slated for removal from the PRA standard in a future revision.
Met MUD-E1 Summary Based on review of:
- EGR-NGGC-0003 (9.7)
- CSP-NGGC-2505
- EGR-NGGC-0016
- ADM-NGGC-0004 Met MUD-F1 Summary Based on review of electronic database for a plant change. See MUD-F2 Met MUD-F2 Summary Note: Documentation program is electronic.
Met
- 116 -
FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-07 ID Number: MUD-A1-1 Level of Significance: Suggestion Reviewer: JSH Capability Category: Met OBSERVATION:
Suggestion: Provide direction in process to monitor industry wide operational history. Ensure that component data (generic and plant-specific) includes active fire protection systems, e.g.
fixed suppression, dampers.
BASIS FOR LEVEL OF SIGNIFICANCE:
POSSIBLE RESOLUTION (REVIEWER):
Reference(s):
Personnel Contacted:
ADM-NGGC-004
- 117 -
FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-07 ID Number: MUD-A3-1 Level of Significance: Suggestion Reviewer: JSH Capability Category: Met OBSERVATION:
Suggestion: Add language to monitor updated or new methodologies as appropriate Currently, have language to use updated or new methodologies which reflect current industry and requirements as appropriate.
BASIS FOR LEVEL OF SIGNIFICANCE:
POSSIBLE RESOLUTION (REVIEWER):
Reference(s):
Personnel Contacted:
ADM-NGGC-004
- 118 -
FACT/OBSERVATION REGARDING FIRE PRA (FPRA)
TECHNICAL ELEMENTS Plant Name: Harris 1 Date: 2008-02-07 ID Number: MUD-B4-1 Level of Significance: Finding Reviewer: JSH Capability Category: Not Met OBSERVATION:
Finding: Since fire standard not referenced, those SRs are not evaluated. Fire standard needs to be referenced in 9.2.5; currently only ASME Internal Events. Add latest reference to R.G.
1.200 once fire standard is endorsed BASIS FOR LEVEL OF SIGNIFICANCE:
POSSIBLE RESOLUTION (REVIEWER):
Reference(s):
Personnel Contacted:
ADM-NGGC-0004