ML20129F482

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Summary of 960920 Meeting W/Bwrog in Washington,Dc to Discuss BWROG PSA Certification Process.List of Attendees & Handouts Encl
ML20129F482
Person / Time
Issue date: 10/01/1996
From: Joshua Wilson
NRC (Affiliation Not Assigned)
To: Matthews D
NRC (Affiliation Not Assigned)
References
PROJECT-691 NUDOCS 9610040156
Download: ML20129F482 (45)
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Text

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'l rar UNITED STATES Qg. [ g NUCLEAR REGULATORY COMMISSION ,

' g s- WASHINGTON, D C. 20555  ;

October 1, 1996 l

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! MEMORANDUM T0: David B. Matthews, Chief

. Generic Issues and Environmental Projects Branch

! Division of Reactor Program Management, NRR 1

FROM: James H. Wilson, Senior Project Manager d -

Generic Issues and Environmental Projects Bra FD Division of Reactor Program Management, NRR

SUBJECT:

SUW4ARY OF PUBLIC MEETING HELD ON SEPTEMBER 20, 1996, TO DISCUSS THE BOILING WATER REACTOR OWNERS' GROUP (BWROG) PSA CERTIFICATION PROCESS On September 20, 1996, the staff attend:d a public meeting in the GE Nuclear Energy offices in Washington, DC to discuss the BWROG probabilistic safety dssessment (PSA) certification process. A list of attendees and their -

affiliations is provided as Attachment 1. A copy of the handouts used by the BWROG in its presentation is provided as Attachment 2.

The BWROG has proposed a certification program to assist its members in achieving two objectives; to assure the quality of PSAs for applications, including those associated with risk-informed regulation, and to assure that each utility has a process in place for maintaining the level of quality. The process was described by Ed Burns of Erin Engineering, a contractor to the BWROG. Effectively, the certification process is a structured peer rufew performed by a team of PSA experts drawn from the utility PSA groups and .

contractors. The results of the certification process is a grading from 1 to i 4 for each of the key elements of the PSA, and possibly for the PSA as a whole, though this is not yet decided upon. The higher the grade, the more use that can be made of the PSA in an application. For the highest grade, the PSA could be used as the principal argument in the application, whereas for the lower grades, it would either have to be supplemented by other analyses, or, for the lowest grade, play a subsidiary role. The review process is guided by use of checklists that identify the issues that should be addressed to each of the elements. The BWROG does not, however, intend to write definitive standards for PSA elements, nor, as was made clear during subsequent discussions, do they expect to see such standards in the forthcoming Reg Guides and SRPs.

The BWROG is scheduled to issue a report describing the process and its pilot application to three plants in mid-November. Mike Cheok, of the NRC staff, described the schedule for the development of the Reg Guides and SRPs, and it was agreed that the issuance of the BWROG report is timely in relation to that '

of the preparation of the public comment drafts of the Reg Guides and SRPs.

The BWROG raised the possibility that they might request a slot on the agenda of the ACRS meeting in November. The checklists used to assess the quality of the PSAs are clearly of interest to the authors of the Reg Guides and SRPs.

However, GE has a desire to make the certification process proprietary.

9610040156 961001 .

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4 Subsequent'to the meeting, Rick Hill (GE) stated that GE intends to submit this propriet'ary information to the staff for its information. The information will also be made available to interested members of the public who contact him at (408) 925-5388 and execute a non-disclosure agreement.

Project No. 691 i Attachments: As stated i cc w/ attachments:

See next page l

l

. . .. . .. . . _ . - - - . . . _ . - ~ . . - . . ..

i Subsequent to the meeting, Rick Hill (GE) stated that GE intends to submit thi:, propriet::ry information to the staff for its information. The information will also be made available to interested members of the public who contact him at (408) 925-5388 and execute a non-disclosure agreement.

Project No. 691 Attachments: As stated cc w/ attachments:

See next page DISTRIBtJTION: 'atW Docket File PUBLIC JHWilson TMartin* OGC*

PGEB r/f riaWiF.) RZimmerman* GHolahan

  • ACRS*

DMatthews * - RJones

  • AThadani
  • BSheron* BBoger*

MRubin

  • Document Name: MEETSUM.920 rw 0FC PGEB O ) SC:PGE5k;// ADD:ADTh C:PG b h NAME JWilso[:sw RArchitzelA R[o(( DMatthNs1 DATE 9/14/96 '@/ /9d 9/M/96 l h/ l /96 0FFICIAL RECORD COPY ,

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$ Boiling Water Reactor Owners' Group cc: C. D. Terry Vice President, Nuclear Engineering Niagara Mohawk Power Corporation Nine Mile Point-2 PO Box 63 Lycoming, NY 13093 D. B. Fetters PECO Energy Nuclear Group Headquarters MC 62C-3 965 Chesterbrook Blvd.

. Wayne, PA 19087 R. A. Pinelli GPU Nuclear MCC Building E ,

One Upper Pond Road l Parsippany, NJ 07054 S. J. Stark GE' Nuclear Energy 175 Curtner Ave, M/C 165 San Jose, CA 95125 T. J. Rausch Commonwealth Edison Company Nuclear Fuel Services 1400 Opus Place, 4th Floor ETWIII Downers Grove, IL 60515 l

. Attachment 1 LIST OF ATTENDEES AT MEETING WITH BWROG HELD IN WASHINGTON, DC ON SEPTEMBER 20, 1996 l

t 88t1E AFFILIATION -

G. Parry NRR/NRC M. Cheok NRR/NRC R. Hill GE G. Krueger PECO I.nergy E. Burns Erin Engineering T. Brooks INPO C. Yeh

  • NYPA A. Knoll PG&E R. Kirchner Niagara Mohawk G. Smith Entergy S. Meyer Centerior Energy R. Wachowiak NPPD C. Nierode NSP R. Labrecque Northeast Utilities K. Canavan -

GPU Nuclear 1

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6:

i PSA PeerReview Certification l l

Process Feedback Form 1

1 1

ISSUE:

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RECOMMENDED RESOLUTION.

PRIORITY:

PERSONS RECOMMENDING:

PERSON ORGANIZATION

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, PSA CERTIFICATION *  !

,, Assure the Quality of PSAs for Applications a

and i

Assure a process is available to maintain the Level of Quality 1

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  • Taken from Risk Based Application Task Force White i Paper on Plant Specific PSA Certification.

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INDUSTRY PSA CERTIFICATION PROCESS i

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! PSA Define Grades of i Comparison Certification for Applications

& Pilot M GL 88-20 s M h ay l Projects Rankin *gnificance Basis

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! Peer Review Certification Process i

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i l Certification Certification

! Criteria Team PSAs Certified For j Regulatory Applications i

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Y I PSA Maintenance l '

m Standard Methods & U Pdate j & Insights l

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i l CHRONOLOGY OF \

l THE BWROG PILOTPSA i

!d CERTIFICATION PROCESS

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, Meeting and input Certification - BMOG Review 3 Pilot Process + - ACRS -> Results Plant ->

Dnvelopment - NRC with NRC, Applications

- Other Owner's ACRS l Groups i

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l OPTIONS

(including Industry Approach) i i i

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2 l VIABLE OPTIONS INCLUDE l

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Qualifications Approach: An approach

' that focuses on the peer review process as a "short-cut" method of assuring overall i d . quality at a given point in time.

1

- Consistency Check: Establish a method

, for checking that the methods, data,

! assumptions are consistent with other l l similar PSAs. i l

- Standards Approach: Establish a '

l regulatory Guide or Standard.

i 4

l - Certification Approach: Establish a process that allows a certification of the l PSA and the PSA process.

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Pediaree Process: A rigorous and j thorough approach that involves firmly j establishing the Technical quality of the i

PSA model and documentation.

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SCOPE OF THE PSA PEER CERTIFICATION i' ,

Internal Events Internal Floods Level 2 (LERF) i i

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PSA CERTIFICATION

. Objective: The PSA Peer Review l Certification' Process is Directed at j s Assuring the Plant Specific PSA and its l update process are technically sufficient  ;

j to support PSA Applications I

i A goal is to make the process a positive experience for the host utility and for peer i utility reviewe.rs..

l Peer Review Certification Process l Includes:

i ,

- Guidance Documents j - Models, Data, Crucial Elements l

- Continuing PSA Program Elements

(Living PSA)
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The PSA Peer Review Certification is the 1

primary benefit o -

i SUBSIDIARYOBJEC IVES i!

Assure the qtlality and realistic nature of the PSA d

Assure the methods are at the state of the technology -

Assure use of appropriate data Acknowledge areas where applications may be hindered by modeling assumptions Identify areas where standard approaches which make technical sense could be developed.

- Large LOCA initiating frequency

- Scram Failure Probability

- Use of SDC bb

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i l WHATIS NOT THE PURPOSE l

! a OFPSA CERTIFICATION i

l Extend the state-of the technology i ,

' I Develop new or standard techniques  !

l Replace in-house technical review i

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, BASES FOR PROCESS

\ DEVELOPMENT Loaical: The process needs to be logical

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Derivative: The process needs to be l

l directly derived from accepted principles i related to PSA and good PSA practices.

Discrimination: The process must be

{ capable of discriminating between the l grades of a PSA as appropriate to l l support different PSA applications.

l -

Reproducible: The process needs to be

' reproducible such that equivalent groups of independent experts applying the criteria will come to the same conclusion.

Documented: The process needs to be documented in a form that makes implementation of changes to the PSA straightforward.

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DevelopmentProcess for i

Certification Criteria i

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QUALITY

! ATTRIBUTES I i , ,

CERTIFICATION PSA l GRADES ELEMENTS i

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l CERTIFICATION REQUIREMENTS CERTIFICATION CRITERIA 4

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GRADES ,,

Lowest Highest ,

GRADE 1 2 3 .4 '

Maint. IST Risk EXAMPLES IPE Rule On-Line Based -

GL 89-16 Maint. TS Qualitative Quantitative i

Simplistic

Comprehensive  !

I Increasing Complexity and integration of Elements t

4 i

Risk-Based /

Risk informed Absolute Risk i Analysis within Deterministic issue Specific " Risk-based"  !

Framework Risk Optimization Alternative Periodic Updates Limited or Consistent with  !

No Updates Applications Conservative Realistic 4

Figure 2-4 ATTRIBUTES OF THE PSA GRADES 198C880 21s C10Domareserstes

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l PROPOSED PSA GRAbES

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Grade 1 - Useful for identifyina Severe Accident Vulnerabilities. Accident Manaaement insiahts.

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and General Prioritization of Issues

! a l This grade requires the minimum standard and has satisfied NRC expectations for responding to

, Generic Letter 88-20. Most PSAs are expected l to be capable of meeting these requirements.

l This grade of certification would serve as an

! industry standard.

l -

Grade 2 - Useful for Risk Rankina with l Deterministic Input This grade of certification requires a review of the PSA model, documentation and maintenance program. Certification at this grade would provide assurance that, on a relative basis, the PSA methods and models yield meaningful  !

rankings for the assessment of systems, .

structures, and components, when combined with deterministic insights (i.e., a blended approach)

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\' PROPOSED PSA GRADES  !

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j Grade 3 - Useful for Risk Sianificance with i l Deterministic Input d

, This grade of certification extends the -

l requirements to assure that risk significance

! determinations made by the PSA are l adequate to support regulatory applications, i

! when combined with deterministic insights.

l This grade is expected to be the certification desired by most plants.

l I

Grade 4 - Useful as Primary Basis for Decision-Makina l This grade of certification requires a j .

comprehensive, intensively reviewed study i

which has the scope, level of detail, and j documentation to assure the highest quality of l results. Routine reliance on the PSA as the basis for certain changes is expected as a result of this grade. It is expected that few plants would currently be eligible for this grade of certification.

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.a PSA ELEMENTS FOR CERTIFICATION l

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i l QUALITYATTRIBdTES l l

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Adequate Process l

j Fidelity between model and plant (Accuracy) m; i ,

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Appropriate Scope l i

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Completeness Consistent with Scope l Appropriate methods, models, and software Adequacy of inputs l i

Realistic assessment of risk measures i -

Self consistency Independent review Ease and facility of updates Conclusions follow from the inputs, models, and results Reproducible Clear and scrutable documentation (Highlighting Assumptions) fbb )b

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! CERTIFICATION TEAM ll ii Independence: Members of the team will not be !l l members of the utility responsible for the PSA or  !

contractors that are actively working for the utility.

d "a Expert in Phases of PSA: This is a difficult criteria

, to formalize because of the broad experience base

that is required to effectively implement the -
certification process. Nevertheless, the following guidance provides:

- Bachelors Degree in Engineering / Science /

Mathematics
and

- At least 10 years experience in the nuclear field

and

! - Special focus experience of at least 5 years in one of the key areas of the process

! - PSA (Level 1 or Level 2)

- Organization / Management or i

- BWR Systems

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- Expenence in Performance of PSAs: The l

! i members of the team will have j participated in the performance or managed at least 1 PSA.

- Member of Utility: The Certification team must have adequate utility participation on the team. The team may be augmented by contractors to provide specific areas of expertise and to provide continuity from one review project to the next.

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STEP-BY-STEP APPLICATION OF CERTIFICATION PROCESS AT PILOT PLANT y

l d L step 1 l Gather Plant and i PSA Information  !

OFFSITE l step 2 l 9r Review Plant and PSA information

+ - _ _ _ _9r ___________ _ _ _ _ _ _ _ _ _

', step 31 1r interact with PSA Group 2 Utllity i

to Obtain Overview of PSA '

Presentation si., 4 l 3r Examine Each Level 1 PSA Element , checklist Using Questions and Checklists '

//

step 5 l 9r Verify by Walkdown Spatial Dependencies Step 6 l 9F Examine Results of a PSA Sensitivity I "P Run Performed During Review Ev uaton I of Example ONSITE

' step 7 l 1r Examine the Level 2 2 Checklist PSA Elements //

st., a l 3r Examine the PSA Maintenance 2 Check!!st and Update Process //

l step s l 1r Develop Preliminary Findings and Certification Results steptol 9r Closecut Meeting 9r i steptil 3r OFFSITE Provide Final Documentation

_[ of the Review V esecami

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%l Table 2 3 REVIEW SCHEDULE AND AGENDA MONDAY ))mt Overview Meeting of Team (All) 8 - 9 a.m.

  • Initial Observatio.s and Changes in Focus Overview Presentation by Host Utility (All) 9 a.m. - 12 noon LUNCH l Accident Sequence Models (Reviewers 1 & 2) 1 - 5 p.m.
  • Model Basis .
  • Success Criteria e EOP Interface
  • Description
  • Dominant Saat=nces '
  • Dominant Cutsets (if applicable)  !

System Analysis (Reviewers 4 & 5) 1 - 5 p.m.

  • Documentation
  • Dependency Matrix
  • Success Criteria Bases Summary of Days Findings (All) 6 - 9 p.m.
  • Written items Strengths Weaknesses
  • Open Questions 23s c10cces.mscrtaes

l PSA Catif~"im

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Table 24 (cont'd)

REVIEW SCHEDULE AND AGENDA i

i l TUESDAY h  !

l Data Analysis 8 - 11 a.m.

1 (Reviewer #3) l

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  • Corc W ierd.
  • Common Cause Failure Treatment Accident Response (Reviewers 1 & 2) 8 - 11 a.m.

System Analysis 8 -11 a.m.

(Reviewers 4 & 5)

  • Reactivity Control
  • Depressurization
  • RHR
  • SDC Summary of Mornings Findings (All) 11 a.m. - noon
  • Written items Strengths

- Weaknesses

  • Open Questions LUNCH Host Utility Presentation on A'fWS (All) 1 - 2 p.m.

Accident Sequence 2-40 Ciocoes 2resortaes

4 4

PSA Catifteam \

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! Table 2-3 (cont'd) I REVIEW SCHEDULE AND AGENDA j

TUESDAY (cont'd) IEnt -

System Analysis 2 - 5 p.m.

. (Reviewer 2 & 3)

  • Room Cooling

! e HVAC - t,ontrol Building  !

(Reviewer 1 & 5)

Plant Specific issues (Reviewer 4) 2 -3 p.m.

  • Spatial Dependencies (Reviewer 4) 3 - 5 p.m.
  • Internal Flood Evaluation Summary of Days Findings (All) 6 - 9 p.m. 1
  • Wntten items Strengths l Weaknesses i

e Open Questions 241 Cicoass trascrises

.- -. - - . - _ - - - . . . - _ . _ _ _ - . - . - - . ~ _ _ - - _ . - - -

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, v l Table 2-3 (cont'd)

REVIEW SCHEDULE AND AGENDA l

WEDNESDAY IIDS l Host Utility Presentation on SBO (All) 8 - 9 a.m.

! Accident Sequence

./

j Ouantification Process (Reviewers 1,3, 5) 9 - 11 a.m.

Re-evaluation of Accident Sequence ("./.;;;.;e2&4) 9 - 11 a.m.

! Models l Summary of Mornings Findings (All) 11 a.m. - noon

! LUNCH l

j Walkdown of Plant (Reviewer 2 & 4) 1 - 3 p.m.

j i e internal Flood issues

{

  • Spatialissues
  • Room Cooling

! Accident Sequence End States 1 - 3 p.m.

(Reviewer 1 & 5)

Data 1 - 3 p.m.

4 (Reviewer 3)

I

  • Unique Unavailabilities

! Accident Sequence Overview and (All) 3 - 5 p.m.

Quantification (including HRA, Dependencies)

) Summary of Days Findings (All) 6 - 9 p.m.

i i

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, PSA C.,i.? em Table 2 3 (cont'd)

REVIEW SCHEDULE AND AGENDA THURSDAY 3]ma Level 2 (LERF) (Reviewer 1,3, & 4) 8 - 11 a.m.

Maintenance and Update Process (Reviewers 2 & 5) 8 - 11 a.m.

Summarize Moming Findings (All) 11 a.m. - noon LUNCH Review Host Utility Sensitivity Runs (All) 1 - 2 p.m.

h4 the Summary Sheets on PSA (All) 2 - 3 p.m.

Ebnents/Sub. Elements identify Findings (All) 1 - 3 p.m.

Review Open Questions with PSA (All) -

3 - 5 p.m.

Group Finstre Findings (All) 6 - 9 p.m.

2-43 C1000es 2786crtaes

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[ Table 2-2' 4

PILOT PLANT INVOLVEMENT AND RESOURCE REQUIREMENTS

  • Supply initial liJurirhi (1 Person Week)

IPE or PSA Document Guidance Documents Event Trees Fault Trees HRA and CCF D ;;@i.-e -

Event Tree Dess;phis (if Available) include Sequence Description LERF Basis (may be included in PSA Document)

CETs  !

Dominant Contributors Treatment of Phenomena Sensitivity Studies Host the certification team during the 1 week visit (1 Person Week)

(include Selected Plant Tours) i e

initial Presentation information Desired (0.5 Person Week)

Initial Desired Grade of Certification E4=*M Basis for the Eg=*h i Summary of Plant Principal Design Features Summary of the Maintenance and Update Process Application Examples PSA Group

- Training Management Role in Use of PSA Provide selected tours of the plant to augment the spatial assessments.

2 37 C1000ee m e6cr1308

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Table 2-2 i

PILOT PLANT INVOLVEMENT AND RESOURCE REQUIREMENTS (cont'd)

Assemble all Suppoi%g Documentation (1 person week)

Provide responses to questions as part of the Review Process (1 Person Wook)

> l Provide presentabons on selected topics (2 Person Days)

  • Provide a proof test run of the model

(.5 person Days) ,

i

  • Provide access to the management chain to I discuss the PSA process  ;

Resolution of Comments / Findings l (1.5 Person Weeks)

  • Closeout Meeting (5 Person Days - 1 Person Week)

TOTAL PILOT PLANT 7.5 Person Weeks' Resource Requirement for Certification l

' This estimate is associated with a PSA with good documentation and technical bases. With excellent documentation and Technical Bases, this estimate could be reduced to 5 person weeks. With reduced levels of documentation, the estimate could be as high as 10 person weeks.

2 38 Cicoasseeswiaes

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EXAMPLE OF PROCESS '

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PSA Element: Initiating Events Example e

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l Sub-elements for Initiating Events j

Criteria for Initiating Events Applicable Grades I

Peer Review Summary Form 55bb$

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Table 32 4

l 6: INITMTING EVENT RELATED GRADES i

! PSA GRADES j CRITERIA

1 2 3 4 f GUIDANCE l . Descrees the process used / / /

l . Consistent with industry practices / / /

Sumcient detal prwided for reproducing the evaluation 1

/ / /

} GROUPING A

l -

Grouped initiators by plant response consistent with event tree structure / / /

)

e and success criteria i .

For rnulti unit sites with shared systems, the impact d inittstors requiring / / / /

l simultaneous response (e.g. LOOP, ions d cooling source due to ice, i loss d an AC or DC bus etc.) are induded l Initiators considered cover the spectrum W intomal event C": ,g (1) / / /

4 l . An experience initiators are accounted for in the model / / / /

Basis for exclusion of initletors is documented / / / /

j .

Perform an FMEA for plant support systems to determine W a specialloss / / / /

j d support system initiator presents a unique chauenge to the plant 1

( . Subsumed initiating events are traceable and bounded /

1

/ / /

i .

Subsumed initiating events are acceptable,g /

Subsumed initiating events are mecarvahla in non.rlsk signiReant / /

] sequences or notwisk signlReant initiators, g j .

Complete list of initiating events within the state of the technology. /

j Detaled plant specine development.

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Initiating event frequencies and recovery are consistent with industry / / / /

experience or analysis
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Plant speclRc features are reRected in the initiating event frequency and / (2) (2) (2) l '****'Y

' / / /

s .

Plant specMc experience remar*ad in the initiating event deRnitions and / / i 1 frequency plus recovery inputs where appropriate

. Plant speelRc models or FMEAs are used to quaney initiating event /

j frequencies and twi where appropriate l 4 W1annaa em

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PSA Ce & w I F l Table 3-2 i INITIATING E'KNT RELATED GRADES i

i PSA GRADES i CRITERIA

1 2 3 4 I I -

1 DOCUMENTATION i

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Documortation provides the basis of the quantNied h and is / /

traceable / / l Documentatim reRects the process used f f f f i

. h Documentation provides the basis for :he initleting event frequency / / / /

groupings l Independent review provided for the document results / / / /

m Cmservatively treet the spectrtan with at least bounding analysis.

i LOOP frequency based on NUREG 1032 or equhlent; ISLOCA frequency based on piara p features and NSAC-154 or equivalent. ,

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1 PSA Cerf4kadost Table 2 4 DIFFERENTIATION AMONG PSA GRADE LEVELS (Selected issues) 25 Gedes j PSA Element Attdbutes i Grade 1 Grade 2 Grade 3 Grade 4 j t

initiating Events Completeness Subsumed IEs Are Norwisk signWicant Norwisk signWicent Complete Nut dIEe e i acceptable subsumed IEs ars =h=ned IEs are stateef-technology acceptable acceptable (Delaged developmer$

Frequencies Generic or Conservettve Generic and Reallatic Realistic and use of Plant Realistic and use W Plant  !

In dominent SpeclRc Date SpecEle Data j contributors  :

i Event Tree Dominent Sequences X X X X  ;

Evolustion

Dominent Contributors X l X X X j Thermal Hydraulic Success Criterie: Level Conservative or Generic Generic and ReeNetic Plant Specule and Plant SpecMc and ResRude Ansiysis or pient specMclty Reensac System Analysis Systems with dete5ed Safety Systems Safety Systems & Key Systems AR Systems models (

Selected BOP i i

Den Den chesacterizelori Genede or h Generic mid m m and use W N W malesed M [

In dominent Specille Data SpecMc Data  !

contributors Review of operating No operating experience Dominent Contrbutors Operating Experience Operating Expedance expwience review reviewed vs. operenng Review of LERs and Review of LERs and experience system pedomience system podermance f moo cianosearecerisse  !

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Totdo 2-4 DIFFERENTIATION AMONG PSA GRADE LEVELS (Selected issues)

I PSA Bsment Antibutes i Grade 1 Grade 2 Gende 3 Grade 4  !

Dependencies Common Cause Fogure Generic CCF values . Use NUREG/CR- . Use NUREG/CR- 4780 Fim NUREG/CR47BO (CCF) ' 4780 to develop to develop CCF evolussion W CCF i CCF gmups gmupe ,

. Generic CCF values . Use of plant speelRe cpenene supeelsrce to conurm or madry  !

CCF values and -

I gmups Human RollebElty Level W detag Screening or detesed Deto5ed for dominent DeleBed for dominent DeleBed gar dominert Ana#ysis contributors conesbutore coneributore  :

Post-Initiator His Minimal required Dominent contrbutors HRA reviewed by Wie l#tA reviewed try Wie reviewed by operating reviewed by operenne operming seenand their operedne seusandinser  !

eten eles input inceuded in the input indesed m the pmoess process 1 Recovery May or may not be As;ri may be Systemelle appliceAlan of Systemede oppAussen of 5 included included ::';2;fi recovery acdone recoveryaedons

  • i Model Scope Umited Within the scope Within the scope kwearten gd scope Level 1  ;

QuentIncation dannition, a deteBed dellntion, a deteBed and 2 vvWe hetiinsamel  !

treatment of the treatment of identsled and assomsf intheore I dominent conntbutore leaves ,

t I

t 2 31 csosasseresetess l i

MW Table 2-4 DIFFERENTIATION AMONG PSA GRADE I.tW (Selected issues)

Grades PSA Element Attributes Grada 1 Grade 2 Grade 3 Grade 4 Model Screening Screening (10# /yr) 10*/yrm 10*/F 10*/yr Quentmcatkwi Truncetion (CDF)m (cont'd)

Containment Scope Screening Level 2: Level 2: twel2:

Performance Dominent toture mode Dominent and Laos All postulated leBure contributors Signmcent modes _.-

(For LERF) Contributors (For LERF)

(For LERF) .

Phenomena Screening Approach Screening Approach Screening Approach AN postdmed phenomena (For LERF) (For LERF) considered and moduisd to recognere sense et technology (For LERF)

Structural Containment Conservative Generic and ReeNetic Plant SpecMc and Plant SpecMc and ResAude  ;

Response Rennstic i Maintenance Process Not Required Required Required Required a

Update j ,

l 2-32 Ciencepresortees i

4 i

PSA CERTIFICATION RESULTS:

PROCESS ORIENTED -

e.1 I

i

  • 1 I

i -

Findings by PSA Element l l

Summary Findings I

1 i

i I

i i

i i

1 I

i l

. - . - - _ . . . _ . . - - - - - ~ - - - - - . - - - - - - . - - - - - - -

l2 Table 5.21 lo*

i ELEMENT: INITIATING EVENTS j Gem-@ocumentation:

i i

Grouping

I Treatment of Seppert System /Special Initiators:

l i I t

Treatment ofInterfacing Systems LOCA & BOC

Data:

Recommended Enhancements:

Overall Process Anessment:

Recommended Certification Grade:

Grade 1 - Supports Assessment ofPlant Vulnerabilities Grade 2 - Supports Risk Ranking Applications Grade 3 - Supports Risk Significance Evaluations w/ Deterministic Input Grade 4 - Provides Primary Basis For Application

.~,

l Table 5.3-1 ~

e

SUMMARY

REPORT

~

i l

OVERALL ASSESSMENT i

l FSA ELEMENT GRADE l l l Initiating Events l

l Accident Sequence Evaluation l

l Thermal Hydraulic Analysis l l l l System Analysis '

l l l Data Analysis l

l l Human Reliability Analysis l

! l Dependencies I

j l Structural Response l

l Quantification l 1 l Containment Performance l l Maintenance & Update l l -l Overnli Assessment:

l l

Overall Certification Grade:

Grade 1 - Supports A-ssment ofPlant Vulnerabilities Grade 2 - Supports Risk Ranking Applications Grade 3 - Supports Risk Significance Evaluations w/ Deterministic Input Grade 4 - Provides Primary Basis For Application Areas Requiring Enhancement:

Areas Recommended For Enhancement:

.1 i

\

Fact / Observation Regarding \ 1 i

PSA TechnicalElements l d

! OBSERVATION:

l l l LEVEL OF SIGNIFICANCE:

l l

POSSIBLE RESOLUTION:

PLANT RESPONSE OR RESOLUTION:

a ;  % .

i

. , l

,i e

LEVEL OFIMPORTANCE  ; l l

i i

Importance i

Level Defindon i

l A. Extremely important and necessary to I 4

address to assure the technical j adequacy of the PSA or the quality of i

the PSA update process. (Contingent Item for Certification.)

B. Important and necessary to address,  !

! but may be deferred until the next PSA l

l update. (Contingent item for I l Certification). i l

l C. Marginal importance, but considered desirable to maintain maximum i flexibility in PSA Applications and j consistency in the industry.

! D. Editorial or Minor Technical item, left l to the discretion of the host utility 4

i

4

' i l:  :.-

l r

i

, l PROCESS ua i IMPROVEMENTS l

Inputs from: ~

i l - Certification Team i

- Host Utility l

l

-IRBR

(

i i

\

l '

l l

t k

1

[

i f

_ _ . . . , _ . _ . _ . . _ . . . _ . , _ . . , _ _ . . _ _ _ _ . . _ . , , _ _ _ _ . _ _ _ , . . _ . _

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