ML14297A266

Record of Review, Brunswick Steam Electric Plant, Units 1 and 2, LAR Attachment U- Table U-1 Internal Events PRA Peer Review- Facts and Observations (F&Os), 10/24/14

ML14297A266
Person / Time
Site:	Brunswick
Issue date:	10/24/2014
From:	Cj Fong NRC/NRR/DRA/APLA
To:
Fong C, NRR/DRA, 415-8474
References
Download: ML14297A266 (4)

Text

Record of Review Dispositions to Brunswick Internal Events PRA Facts and Observations (F&Os)

FINDING/

ACCEPTABLE TO STAFF VIA SUGGESTION (F&O) ID OR Review of RAI Response SUPPORTING Plant REQUIREMENT Disposition Not Discussed in SE Discussed in (SR) (A/B/C) SE F&O 4-2 A F&O 1-3 C F&O 6-1 A F&O 6-4 C F&O 1-15 A F&O 1-11 A F&O 6-8 See PRA-RAI-18.a. Acceptable to NRC staff because the licensee identified use of a computer code (i.e., GOTHIC) as beyond those used in the SAR to establish success criteria, and explained that open issues and potential errors reported to the users group for this version were checked for non-impact on the analyses.

F&O 4-5 See PRA-RAI-18.b. Acceptable to NRC staff because the licensee explains it takes a check valve, MOV, and an AOV failure to create a diversion path. The sum of this combination of failures is 1E-15, and therefore cannot have a meaningful impact on the fire PRA.

F&O 3-3 See PRA-RAI-18.c. Acceptable to NRC staff because the licensee explains that procedure talk-throughs were included as part of the operator interviews and that the results were recorded as part of the electronic input files associated with HRA Calculator runs and documented as an output of their HRA report.

F&O 3-4 See PRA-RAI-18.c. Acceptable to NRC staff because the licensee explains that procedure talk-throughs were included as part of the operator interviews and that the results were recorded as part of the electronic input files associated with August 29, 2014 1

Record of Review Dispositions to Brunswick Internal Events PRA Facts and Observations (F&Os)

FINDING/

ACCEPTABLE TO STAFF VIA SUGGESTION (F&O) ID OR Review of RAI Response SUPPORTING Plant REQUIREMENT Disposition Not Discussed in SE Discussed in (SR) (A/B/C) SE HRA Calculator runs and documented as an output of their HRA report F&O 3-8 B F&O 3-6 B F&O 2-3 See PRA-RAI-18d. Acceptable to NRC staff because the licensee explains that no internal events HFEs were screened but rather all HFEs were retained and specifically evaluated in the fire PRA.

F&O 2-2 See PRA-RAI-18.d. Acceptable to NRC staff because the licensee explains that a review of plant specific operating data over several years showed standby times to be equally split among trains.

F&O 1-2 A F&O 3-9 A F&O 2-7 A F&O 4-7 A F&O 3-12 C F&O 3-11 C F&O 3-13 C F&O 1-19 A F&O 6-12 See PRA-RAI-18.f. Acceptable to NRC staff because the licensee describes key limitations associated with LERF modeling. The licensee explains that minimal or no credit is provided for recovery of failed equipment and inadequate injection after containment failure due to lack of information about human and equipment performance in adverse conditions; that certain secondary systems are assumed to failed for all scenarios (same as for CDF scenarios); and that truncation was limited to 1E-10/year for LERF because of excessive quantification August 29, 2014 2

Record of Review Dispositions to Brunswick Internal Events PRA Facts and Observations (F&Os)

FINDING/

ACCEPTABLE TO STAFF VIA SUGGESTION (F&O) ID OR Review of RAI Response SUPPORTING Plant REQUIREMENT Disposition Not Discussed in SE Discussed in (SR) (A/B/C) SE time needed for lower limits.

F&O 1-21 thru See PRA-RAI-6-20 18.g, PRA-RAI-18.h, and PRA-RAI-18.g.01.

F&O 1-21 C F&O 1-22 C F&O 1-23 C F&O 1-24 C F&O 1-25 C F&O 1-20 C F&O 1-24 C F&O 6-16 C F&O 1-26 C F&O 1-27 C F&O 6-18 C F&O 1-28 C F&O 1-31 C F&O 6-15 C F&O 3-14 C F&O 2-9 C F&O 1-32 C F&O 2-10 C F&O 6-13 C F&O 1-33 C F&O 6-14 C F&O 6-20 C 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 August 29, 2014 3

Record of Review Dispositions to Brunswick Internal Events PRA Facts and Observations (F&Os)

FINDING/

ACCEPTABLE TO STAFF VIA SUGGESTION (F&O) ID OR Review of RAI Response SUPPORTING Plant REQUIREMENT Disposition Not Discussed in SE Discussed in (SR) (A/B/C) SE 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.

August 29, 2014 4