ML15054A037

U.S. Nuclear Regulatory Commission, Record of Review Dispositions to Fire PRA Facts and Observations for Turkey Point Nuclear Generating Stations, Units 3 and 4

ML15054A037
Person / Time
Site:	Turkey Point
Issue date:	02/23/2015
From:	Fields L C NRC/NRR/DRA/APLA
To:
Fields L C, NRR/DRA
References
Download: ML15054A037 (12)

Text

Record of Review Dispositions to Turkey Pont PRA Facts and Observations (F&Os)

FINDING/SUGGESTION (F&O) ID OR SUPPORTING REQUIREMENT (SR) FIRE PRA F&Os ACCEPTABLE TO STAFF VIA Review of Plant Disposition (A/B/C) RAI Response Not Discussed in SE Discussed in SE 1-1 A 1-2 See PRA RAI 01.ee. Acceptable to the NRC staff because the licensee clarified that a fire-induced reactor trip initiating event was used for Fire PRA quantification but that logic, where applicable, was added to the Fire PRA fault tree at a level that would allow the Fire PRA quantification to address the impact of fire-related failures that could result in an alternate initiating event, including those associated with failure of support systems.

1-3 See PRA RAI 01.ee. Acceptable to the NRC staff because the licensee clarified that a fire-induced reactor trip initiating event was used for Fire PRA quantification but that logic, where applicable, was added to the Fire PRA fault tree at a level that would allow the Fire PRA quantification to address the impact of fire-related failures that could result in an alternate initiating event, including those associated with failure of support systems.

1-10 See PRA RAIs 01.a and 01.a.01. 1-17 A 1-18 See PRA RAI 01.b. Acceptable to the NRC staff because the licensee clarified that supplemental walkdowns to identify missing ignition sources were performed as part of the fire scenario refinement process for fire compartments with significant CDF and LERF contributions.

1-19 B 1-25 See PRA RAI 01.c. Acceptable to the NRC staff because the licensee stated that a review of non-significant cutsets was

Record of Review Dispositions to Turkey Pont PRA Facts and Observations (F&Os)

FINDING/SUGGESTION (F&O) ID OR SUPPORTING REQUIREMENT (SR) FIRE PRA F&Os ACCEPTABLE TO STAFF VIA Review of Plant Disposition (A/B/C) RAI Response Not Discussed in SE Discussed in SE performed and that these cutsets were found to be valid. 1-27 See PRA RAIs 01.d, 01.d.01 and 27.e.01. 1-34 See PRA RAI 01.e and 01.e.01. Acceptable to the NRC staff because the licensee clarified that all credited barriers were verified, via walkdowns and review of fire barrier drawings, to be of substantial build and capable of confining heat and products of combustion. Additionally, fire-induced failure of targets was evaluated independent of the zone in which targets were located, and an MCA was performed.

See PRA RAI 01.e. Note that a portion of the response to Part (v) of this RAI is referenced to clarify the application of

barrier failure probabilities in the MCA. 1-37 A 1-38 See PRA RAI 01.g. Acceptable to the NRC staff because the licensee performed the Fire PRA quantification using the EPRI Risk and Reliability Workstation as well as validated and verified quantification engines FORTE and FTREX. The licensee also explained that Fire PRA model asymmetries are present as a

result of the physical asymmetries that exist for cable and component locations with respect to ignition sources.

1-40 A 2-1 See PRA RAI 01.e and 01.e.01. Acceptable to the NRC staff because the licensee stated that per the FHA, manholes containing redundant safe shutdown cable are sealed to prevent introduction of flammable liquids. Additionally, the licensee clarified that all credited barriers were verified, via walkdowns and review of fire barrier drawings, to be of substantial build and capable of See PRA RAI 01.e. Note that a portion of the response to Part (v) of this RAI is referenced to clarify the application of barrier failure probabilities in the MCA.

Record of Review Dispositions to Turkey Pont PRA Facts and Observations (F&Os)

FINDING/SUGGESTION (F&O) ID OR SUPPORTING REQUIREMENT (SR) FIRE PRA F&Os ACCEPTABLE TO STAFF VIA Review of Plant Disposition (A/B/C) RAI Response Not Discussed in SE Discussed in SE confining heat and products of combustion. 2-44 A 3-2 See PRA RAI 01.e and 01.e.01. Acceptable to the NRC staff because the licensee clarified that all credited barriers were verified, via walkdowns and review of fire barrier drawings, to be of substantial build and capable of confining heat and products of combustion. Additionally, fire-induced failure of targets was evaluated independent of the zone in which targets were located, and an MCA was performed.

See PRA RAI 01.e. Note that a portion of the response to Part (v) of this RAI is referenced to clarify the application of barrier failure probabilities in the MCA. 3-3 See PRA RAI 01.e and 01.e.01. Acceptable to the NRC staff because the licensee clarified that spatial separation was not credited.

See PRA RAI 01.e. Note that a portion of the response to Part (v) of this RAI is referenced to clarify the application of barrier failure probabilities in the MCA. 3-4 See PRA RAIs 01.e, 01.e.01 and 01.f. Acceptable to the NRC staff because the licensee clarified that no active barriers or barrier systems are credited in the Fire PRA.

See PRA RAI 01.e. Note that a portion of the response to Part (v) of this RAI is referenced to clarify the application of barrier failure probabilities in the MCA. 3-5 See PRA RAI 01.h. Acceptable to the NRC staff because although the licensee did not sufficiently address PRA RAI 01.h, the deficiency identified by this F&O has no impact on the evaluations relied upon to support fire risk evaluations or on the conclusions of the risk assessment.

3-7 A 3-8 A 4-17 See PRA RAIs 01.i and 01.i.01. 5-11 A 5-13 B Record of Review Dispositions to Turkey Pont PRA Facts and Observations (F&Os)

FINDING/SUGGESTION (F&O) ID OR SUPPORTING REQUIREMENT (SR) FIRE PRA F&Os ACCEPTABLE TO STAFF VIA Review of Plant Disposition (A/B/C) RAI Response Not Discussed in SE Discussed in SE 6-9 See PRA RAIs 01.j, 01.j.01 and 01.j.01.01. 6-10 A 6-16 See PRA RAIs 01.k and 01.k.01. Note that F&O 6-16, a finding, appears in the original LAR submittal; however, given that it was closed by the 2012 focused scope peer review, it does not appear in the revised Attachment V, Table V-3 provided as supplement to the LAR. 6-20 A 7-1 See PRA RAI 01.ee. Acceptable to the NRC staff because the licensee clarified that a fire-induced reactor trip initiating event was used for Fire PRA quantification but that logic, where applicable, was added to the Fire PRA fault tree at a level that would allow the Fire PRA quantification to address the impact of fire-related failures that could result in an alternate initiating event, including those associated with failure of support systems.

7-3 See PRA RAI 01.ee. Acceptable to the NRC staff because the licensee clarified that a fire-induced reactor trip initiating event was used for Fire PRA quantification but that logic, where applicable, was added to the Fire PRA fault tree at a level that would allow the Fire PRA quantification to address the impact of fire-related failures that could result in an alternate initiating event, including those associated with failure of support systems. In the disposition to F&O 7-3, the licensee stated that no new accident progressions requiring modification of the LERF model

Record of Review Dispositions to Turkey Pont PRA Facts and Observations (F&Os)

FINDING/SUGGESTION (F&O) ID OR SUPPORTING REQUIREMENT (SR) FIRE PRA F&Os ACCEPTABLE TO STAFF VIA Review of Plant Disposition (A/B/C) RAI Response Not Discussed in SE Discussed in SE were identified. 7-6 See PRA RAIs 01.l and 01.l.01. 7-8 See PRA RAIs 01.m, 01.m.01, and 01.m.02. 8-3 A 8-5 A 8-8 A 8-10 See PRA RAI 01.n. Acceptable to the NRC staff because the licensee clarified that the process used to apply screening HFEs to the Fire PRA model eliminates potential non-minimal cutsets and the model anomaly referenced by this F&O. The licensee further clarified that there is consequently no impact on total risk and delta risk.

9-1 See PRA RAI 01.o. 9-4 See PRA RAI 01.o. 9-5 See PRA RAIs 01.p and 01.p.01. 9-6 See PRA RAIs 01.q and 01.q.01. 9-10 See PRA RAIs 01.r, 01.r.01, 01.r.02, 01.r.02.c.01, 08 and 08.01. 9-11 B 10-1 See PRA RAIs 01.t, 01.t.01, and 01.t.01.01. 10-2 See PRA RAI 01.s. Acceptable to the NRC staff because the licensee confirmed that miscellaneous hydrogen fire scenarios have been incorporated in the Fire PRA for the charging pump room fire areas. In lieu of postulating individual hydrogen fire scenarios for the charging pump rooms, a total room damage CCDP is assumed.

10-3 See PRA RAIs 01.t, 01.t.01, and 01.t.01.01. 10-4 See PRA RAI 01.u.

Record of Review Dispositions to Turkey Pont PRA Facts and Observations (F&Os)

FINDING/SUGGESTION (F&O) ID OR SUPPORTING REQUIREMENT (SR) FIRE PRA F&Os ACCEPTABLE TO STAFF VIA Review of Plant Disposition (A/B/C) RAI Response Not Discussed in SE Discussed in SE 10-6 See FM RAIs 01.n and 01.s. 10-8 B 10-9 See PRA RAIs 01.v and 01.v.01. 10-11 B 10-12 See PRA RAI 01.w. Acceptable to the NRC staff because the licensee explained that the Fire PRA addressed each of the potential damage mechanisms presented in Appendix T of NUREG/CR-6850.

10-13 See PRA RAIs 01.r, 01.r.01, 01.r.02, 01.r.02.c.01, 08 and 08.01. 10-14 See PRA RAI 01.x and FM RAI 04. 10-15 See PRA RAI 01.cc. Acceptable to the NRC staff because the licensee confirmed that no dependency exists between detection systems credited for automatic suppression and detection systems credited for manual brigade response.

10-16 PRA RAIs 01.y, PRA RAI 01.y-01, FM RAI 01.j and FM RAI 01.k. 10-17 See PRA RAI 01.dd, PRA RAI 01.dd.01 and FM RAI 01.h. 10-18 See PRA RAIs 01.z, 01.z.i.01, and 01.z.ii.01. 10-19 See PRA RAIs 01.z, 01.z.i.01, and 01.z.ii.01. 10-20 A 10-21 B 10-22 See PRA RAI 01.aa. Acceptable to the NRC staff because the licensee stated that an approach consistent with FAQ 13-0004 was used however, in lieu of using the thermoset heat flux damage threshold for components mounted inside a control panel

Record of Review Dispositions to Turkey Pont PRA Facts and Observations (F&Os)

FINDING/SUGGESTION (F&O) ID OR SUPPORTING REQUIREMENT (SR) FIRE PRA F&Os ACCEPTABLE TO STAFF VIA Review of Plant Disposition (A/B/C) RAI Response Not Discussed in SE Discussed in SE per FAQ 13-0004, the licensee conservatively assumed the thermoplastic threshold. 10-23 See PRA RAI 01.bb. Acceptable to the NRC staff because the licensee addressed the potential failure of components modeled in Fire PRA due to suppression effects for the types of manual and automatic manual suppression systems or activities credited.

A: For F&Os, the NRC staff finds that the disposition of the F&O as described by the licensee in the LAR provides confidence that the issues raised by the F&O have been addressed and, if needed, the PRA has been modified, and therefore the resolution of the F&O is acceptable for this application. For Not Met or met at CC-I SRs, the NRC staff finds that the acceptability basis for the capability category of the SR as described by the licensee in the LAR provides confidence that the requirements of the SR have been addressed and, if needed, the PRA has been modified, and therefore the PRA quality with respect to the SR is acceptable for this application. Examples of acceptable Not Met and CC-I SRs are modeling methods that yield conservative FRE and change evaluation results.

B: For F&Os, the NRC staff finds that the disposition of the F&O as described by the licensee in the LAR and further clarified during the audit provides confidence that the issues raised by the F&O have been addressed and, if needed, the PRA has been modified, and therefore the resolution of the F&O is acceptable for this application. For Not Met or met at CC-I SRs, the NRC staff finds that the acceptability basis for the capability category of the SR as described by the licensee in the LAR and further clarified during the audit provides confidence that requirements of the SR have been addressed and, if needed, the PRA has been modified, and therefore the PRA quality with respect to the SR is acceptable for this application. Examples of acceptable Not Met and CC-I SRs are modeling methods that yield conservative FRE and change evaluation results.

C: For F&Os, the NRC staff finds that the resolution of the F&O, as described by the licensee in the LAR, would have a negligible effect on the evaluations relied upon to support fire risk evaluations and has no impact on the conclusions of the risk assessment and therefore the resolution of the F&O is acceptable for this application. Examples of such F&Os may be suggestions, as well as those F&Os that don't affect the fire PRA. Documentation issues may fall into this category as well. For Not Met or met at CC-I SRs, the NRC staff finds that the acceptability basis for the capability category of the SR, as described by the licensee in the LAR, would have a negligible effect on the evaluations relied upon to support fire risk evaluations and has no impact on the conclusions of the risk assessment and therefore the PRA quality with respect to the SR is acceptable for this application. Examples are those SRs that don't affect the fire PRA.

Record of Review Dispositions to Turkey Pont PRA Facts and Observations (F&Os)

FINDING/SUGGESTION (F&O) ID OR SUPPORTING REQUIREMENT (SR) INTERNAL EVENTS PRA F&Os ACCEPTABLE TO STAFF VIA Review of Plant Disposition (A/B/C) RAI Response Not Discussed in SE Discussed in SE AS-1 B AS-2 B AS-3 B AS-9 B DA-1 See PRA RAIs 17 and 17.01. DA-2 B DA-4 See PRA RAI 27.g. Acceptable to the NRC staff because the licensee sufficiently described the process by which data was updated and the basis for time periods encompassed by the data analysis, providing justification for the exclusion of plant-specific data.

DA-7 See PRA RAIs 17 and 17.01. DE-1 See PRA RAIs 17 and 17.01. DE-2 C HR-A2-01 See PRA RAIs 25 and 27.b. Acceptable to the NRC staff because the licensee described that rather than examining all possible maintenance, surveillance, and calibration procedures and associated practices, the licensee assumes pre-initiators for all PRA-credited redundant standby trains may occur at HEP screening values, which were made consistent with NUREG-1792 in response to PRA RAI 25. Detailed HRA, including review of plant maintenance, surveillance, and calibration procedures and practices, was performed for all risk significant pre-initiators.

HR-B2-01 See PRA RAIs 25 and 27.b. Acceptable to the NRC staff because the licensee clarified that rather than examining all possible maintenance, surveillance, and calibration procedures and associated practices, the licensee assumed pre-initiators for all PRA-credited redundant standby trains at HEP screening values, which

Record of Review Dispositions to Turkey Pont PRA Facts and Observations (F&Os)

FINDING/SUGGESTION (F&O) ID OR SUPPORTING REQUIREMENT (SR) INTERNAL EVENTS PRA F&Os ACCEPTABLE TO STAFF VIA Review of Plant Disposition (A/B/C) RAI Response Not Discussed in SE Discussed in SE were made consistent with NUREG-1792 in response to PRA RAI 25. Detailed HRA, including review of plant maintenance, surveillance, and calibration procedures and practices, was performed for all risk significant pre-initiators. HR-C2-01 B HR-D1-01 B HR-D3-01 B HR-G7-01 See PRA RAI 27.c. Acceptable to the NRC staff because the licensee justified the risk impact of those instances when only three reactor operators would be present to respond to a dual-unit initiating event to be insignificant.

IE-3 B IE-4 B IE-7 B IE-9 See PRA RAI 27.c. Acceptable to the NRC staff because the licensee clarified that RCP seal LOCA initiators are modeled functionally in the PRA as a failure of seal cooling and injection in lieu of a specific random initiator.

IFPP-B3-01 C IFQU-A1-01 C IFQU-A5-01 C IFQU-A7-01 C IFSN-A11-01 C IFSN-A16-01 C IFSN-A2-01 C IFSN-A3-01 C IFSN-A4-01 C IFSN-A6-01 C IFSN-A8-01 C IFSO-A1-01 C IFSO-A3-01 C IFSO-A4-01 C IFSO-A5-01 C L2-1 See PRA RAIs 17 and 17.01. MU-2 B MU-4 B MU-5 B Record of Review Dispositions to Turkey Pont PRA Facts and Observations (F&Os)

FINDING/SUGGESTION (F&O) ID OR SUPPORTING REQUIREMENT (SR) INTERNAL EVENTS PRA F&Os ACCEPTABLE TO STAFF VIA Review of Plant Disposition (A/B/C) RAI Response Not Discussed in SE Discussed in SE QU-2 B QU-3 B QU-5 See PRA RAIs 27.e and 27.e.01. QU-6 B QU-8 B ST-1 See PRA RAIs 17 and 17.01.

SY-2 See PRA RAI 27.f. Acceptable to the NRC staff because the licensee justified that the precursor to loss of CCW identified by the peer review team was not applicable to the at-power internal events PRA model.

TH-1 See PRA RAIs 17 and 17.01. TH-3 B TH-4 B IE-2 A Note that the licensee's disposition to this F&O was provided in response to PRA RAI 27.a HR-3 A Note that the licensee's disposition to this F&O was provided in response to PRA RAI 27.a DA-D5-01 C Note that the licensee's disposition to this F&O was provided in response to PRA RAI 22. DA-D6-01 C Note that the licensee's disposition to this F&O was provided in response to PRA RAI 22. DA-D6-02 C Note that the licensee's disposition to this F&O was provided in response to PRA RAI 22. IE-C14-01 C Note that the licensee's disposition to this F&O was provided in response to PRA RAI 22. IE-C14-02 C Note that the licensee's disposition to this F&O was provided in response to PRA RAI 22. IE-C14-03 C Note that the licensee's disposition to this F&O was provided in response to PRA RAI 22. IE-C14-04 C Note that the licensee's disposition to this F&O was provided in response to PRA RAI 22. IE-C14-05 C Note that the licensee's disposition to this F&O was provided in response to PRA RAI 22. IE-C14-06 C Note that the licensee's disposition to this F&O was provided in Record of Review Dispositions to Turkey Pont PRA Facts and Observations (F&Os)

FINDING/SUGGESTION (F&O) ID OR SUPPORTING REQUIREMENT (SR) INTERNAL EVENTS PRA F&Os ACCEPTABLE TO STAFF VIA Review of Plant Disposition (A/B/C) RAI Response Not Discussed in SE Discussed in SE response to PRA RAI 22. IE-C14-07 C Note that the licensee's disposition to this F&O was provided in response to PRA RAI 22. LE-D2-01 C Note that the licensee's disposition to this F&O was provided in response to PRA RAI 22. LE-F1-01 C Note that the licensee's disposition to this F&O was provided in response to PRA RAI 22. LE-G5-01 C Note that the licensee's disposition to this F&O was provided in response to PRA RAI 22. IE-C14 C Note that the licensee's assessment of this SR was provided in response to PRA RAI 22. SY-C3 C Note that the licensee's assessment of this SR was provided in response to PRA RAI 22. DA-D6 C Note that the licensee's assessment of this SR was provided in response to PRA RAI 22. QU-D5 C Note that the licensee's assessment of this SR was provided in response to PRA RAI 22. LE-F1 C Note that the licensee's assessment of this SR was provided in response to PRA RAI 22. LE-G3 C Note that the licensee's assessment of this SR was provided in response to PRA RAI 22. LE-G5 C Note that the licensee's assessment of this SR was provided in response to PRA RAI 22.

A: For F&Os, the NRC staff finds that the disposition of the F&O as described by the licensee in the LAR provides confidence that the issues raised by the F&O have been addressed and, if needed, the PRA has been modified, and therefore the resolution of the F&O is acceptable for this application. For Not Met or met at CC-I SRs, the NRC staff finds that the acceptab ility basis for the capability category of the SR as described by the licensee in the LAR provides confidence that the requirements of the SR have been addressed and, if needed, the PRA has been modified, and therefore the PRA quality with respect to the SR is acceptable for this application. Examples of acceptable Not Met and CC-I SRs are modeling methods that yield conservative FRE and change evaluation results.

B: For F&Os, the NRC staff finds that the disposition of the F&O as described by the licensee in the LAR and further clarified during the audit provides confidence that the issues raised by the F&O have been Record of Review Dispositions to Turkey Pont PRA Facts and Observations (F&Os) addressed and, if needed, the PRA has been modified, and therefore the resolution of the F&O is acceptable for this application. For Not Met or met at CC-I SRs, the NRC staff finds that the acceptability basis for the capability category of the SR as described by the licensee in the LAR and further clarified during the audit provides confidence that requirements of the SR have been addressed and, if needed, the PRA has been modified, and therefore the PRA quality with respect to the SR is acceptable for this application. Examples of acceptable Not Met and CC-I SRs are modeling methods that yield conservative FRE and change evaluation results.

C: For F&Os, the NRC staff finds that the resolution of the F&O, as described by the licensee in the LAR, would have a negligible effect on the evaluations relied upon to support fire risk evaluations and has no impact on the conclusions of the risk assessment and therefore the resolution of the F&O is acceptable for this application. Examples of such F&Os may be suggestions, as well as those F&Os that don't affect the fire PRA. Documentation issues may fall into this category as well. For Not Met or met at CC-I SRs, the NRC staff finds that the acceptability basis for the capability category of the SR, as described by the licensee in the LAR, would have a negligible effect on the evaluations relied upon to support fire risk evaluations and has no impact on the conclusions of the risk assessment and therefore the PRA quality with respect to the SR is acceptable for this application. Examples are those SRs that don't affect the fire PRA.