PLA-7193, Request to Continue Use of a Risk-Informed Inservice Inspection Alternative in a Proposed Relief Request No. 4RR-01 to the Fourth 10-Year Inservice Inspection Program

Request to Continue Use of a Risk-Informed Inservice Inspection Alternative in a Proposed Relief Request No. 4RR-01 to the Fourth 10-Year Inservice Inspection Program

ML14302A443
Person / Time
Site:	Susquehanna
Issue date:	10/29/2014
From:	Franke J Susquehanna
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
PLA-7193
Download: ML14302A443 (82)

Text

Jon A. Franke Site Vice President U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001 PPL Susquehanna, LLC 769 Salem Boulevard Berwick, PA 18603 Tel. 570.542.2904 Fax 570.542.1 504 jfranke@ pplweb.com SUSQUEHANNA STEAM ELECTRIC STATION REQUEST TO CONTINUE USE OF A RISK-INFORMED INSERVICE INSPECTION ALTERNATIVE IN A PROPOSED RELIEF REQUEST NO. 4RR-01 TO THE FOURTH 10-YEAR INSERVICE INSPECTION PROGRAM FOR SUSQUEHANNA UNITS 1 AND 2 PLA-7193 Docket No. 50-387 and No. 50-388

Reference:

1.

NRC Safety Evaluation (SE), "Third 10-Year Inservice Inspection (IS!) Interval Program Plan (TAC Nos. MC/181 and MC1182)," dated July 28, 2005 (Accession No. ML051990330)

2.

PPL Letter PLA-7178, "Inservice Inspection Program Plan for the Fourth Ten-Year Interval," dated June 2, 2014 Pursuant to 10 CFR 50.55a(a)(3)(i), PPL Susquehanna, LLC (PPL) hereby requests NRC approval of the enclosed relief request associated with the Fourth Ten-Year Inservice Inspection (lSI) Interval for the Susquehanna Steam Electric Station (SSES), Units 1 and 2.

Relief Request (RR) 4RR-01 will continue the use of the Risk-Informed Inservice Inspection (RI-ISI) program as an alternative to the American Society of Mechanical Engineers (ASME)Section XI, lSI Program for Class 1 and 2 (Examination Categories B-F, B-J, C-F-1, and C-F-2) piping welds. The Fourth Ten-Year lSI Interval inspection program uses the ASME Section XI, 2007 Edition through the 2008 Addenda for the examination of these components (Reference 2).

PPL is proposing the use of ASME Code Case N-578-1 for the Risk-Informed evaluation and inspection of Class 1 and 2 components at SSES. Use of Code Case N-578-1 has been approved by the NRC, which was in part the basis for the approved RI-ISI program for ASME Class 1 and 2 components for the Third Ten-Year Inspection Interval (Reference 1 ).

SSES requests NRC's approval prior to the next scheduled refueling outage for Unit 2, in the spring of 2015.

There are no new regulatory commitments contained in this submittal.

Document Control Desk PLA-7193 If you have any questions or require additional information, please contact Mr. Duane L. Filchner (570) 542-6501.

Attachments:

1. 10 CFR 50.55a Request 4RR-01

2. PRA Technical Adequacy Assessment Copy:

NRC Region I Mr. J. Greives, NRC Sr. Resident Inspector Mr. J. Whited, NRC Project Manager Mr. L. Winker, PA DEP/BRP to PLA-7193 10 CFR SO.SSa Request 4RR-01 to PLA-7193 Page 1 of 18 Susquehanna Steam Electric Station, Units 1 and 2 Facility Operating License NPF-14 and NPF-22 NRC Docket Nos. 50-387 and 388 10 CFR 50.55a Request 4RR-01 Proposed Alternative In Accordance with 10 CFR 50.55a(a)(3)(i)

Alternative Provides Acceptable Level of Quality and Safety

1.

ASME Code Component(s) Affected System:

Various ASME Code Class 1 and 2 Systems Code Class:

ASME Code Class 1 and 2 Component

Description:

ASME Code Class 1 and 2 Piping Welds Components Affected:

Weld Numbers Description Various ASME Code Class 1 Piping Welds Various ASME Code Class 1 Piping Welds Various ASME Code Class 2 Piping Welds Various ASME Code Class 2 Piping Welds

2.

Applicable Code Edition and Addenda

Code Code Item Number Category B-F B5.10, B5.140 B-J C-F-1 C-F-2 B9.11, B9.21, B9.31, B9.32, B9.40 C5.11 C5.51, C5.81 The applicable ASME Code,Section XI, for the Fourth Ten-Year Interval of the Inservice Inspection (lSI) Program is the 2007 Edition through the 2008 Addenda.

3.

Applicable Code Requirement

The following Code requirements are paraphrased from the 2007 Edition through the 2008 Addenda of ASME Section XI:

ASME Section XI 2007 Edition through the 2008 Addenda Edition, IWB-2411, requires examinations in each examination category shall be completed during each inspection interval. ASME Section XI 2007 Edition through the 2008 Addenda, IWB-2500 Examination and Pressure Test Requirements (a) Components shall be examined and tested as specified in Table IWB-2500-1. The method of examination for the components and parts of the pressure retaining boundaries shall comply with those tabulated in Table IWB-2500-1 except where alternate examination methods are used that meet the requirements of IW A-2240. Applicable category welds in table IWB-2500-1 are B-F

Inservice Inspection Program 10 CFR 50.55a Request 4RR-01 to PLA-7193 Page 2 of 18 (Pressure Retaining Dissimilar Metal Welds in Vessel Nozzles) and B-J (Pressure Retaining Welds in Piping).

100% of Category B-F welds and 25% of Category B-J welds for the ASME Code, Class 1, non-exempt piping shall be selected for volumetric and/or surface examination based on existing stress analyses and cumulative usage factors.

ASME Section XI, 2007 Edition through the 2008 Addenda Edition, IWC-2411, requires examinations in each examination category shall be completed during each inspection interval in accordance with Table IWC-2411-1. Applicable category welds in Table IWC-2500-1 are C-F-1 (Pressure Retaining Welds in Austenitic Stainless Steel or High Alloy Piping) and C-F-2 (Pressure Retaining Welds in Carbon or Low Alloy Steel Piping).

For Category C-F-1 welds in Class 2 piping, the welds selected for examination shall include 7.5%, but not less than 28 welds, of all dissimilar metal, austenitic stainless steel or high alloy welds not exempted by IWC-1220. (Some welds not exempted by IWC-1220 are not required to be nondestructively examined per Examination Category C-F-1. These welds, however, shall be included in the total weld count to which the 7.5% sampling rate is applied.) The examinations shall be distributed as follows:

(a) the examinations shall be distributed among the Class 2 systems prorated, to the degree practicable, on the number of nonexempt dissimilar metal, austenitic stainless steel, or high alloy welds in each system (i.e., if a system contains 30%

of the nonexempt welds, then 30% of the nondestructive examinations required by Examination Category C-F-1 should be performed on that system);

(b) within a system, the examinations shall be distributed among terminal ends, dissimilar metal welds, and structural discontinuities prorated, to the degree practicable, on the number of nonexempt terminal ends, dissimilar metal welds, and structural discontinuities in that system; and (c) within each system, examinations shall be distributed between line sizes prorated to the degree practicable.

For Category C-F-2 welds in Class 2 piping the welds selected for examination shall include 7.5%, but not less than 28 welds, of all carbon and low alloy steel welds not exempted by IWC-1220. (Some welds not exempted by IWC-1220 are not required to be nondestructively examined per Examination Category C-F-2. These welds, however, shall be included in the total weld count to which the 7.5% sampling rate is applied.)

Inservice Inspection Program 10 CFR 50.55a Request 4RR-01 The examinations shall be distributed as follows: to PLA -7193 Page 3 of 18 (a) the examinations shall be distributed among the Class 2 systems prorated, to the degree practicable, on the number of nonexempt carbon and low alloy steel welds in each system (i.e., if a system contains 30% of the nonexempt welds, then 30%

of the nondestructive examinations required by Examination Category C-F-2 should be performed on that system);

(b) within a system, the examinations shall be distributed among terminal ends and structural discontinuities prorated, to the degree practicable, on the number of nonexempt terminal ends and structural discontinuities in that system; and (c) within each system, examinations shall be distributed between line sizes prorated to the degree practicable.

4.

Reason for Request

In accordance with the provisions of 10 CFR 50.55a, "Codes and Standards," paragraph 10 CFR 50.55a(a)(3), Susquehanna requests relief from the requirement of ASME Code Section XI, Sub-article IWB-2500 and IWC-2500, Tables IWB-2500-1 and IWC-2500-1, Examination Categories B-F, B-J, C-F-1 and C-F-2, "Pressure Retaining Welds in Piping" welds.

ASME Section XI Examination Categories B-F, B-J, C-F-1, and C-F-2 currently contain the requirements for examination of piping components by means of nondestructive examination (NDE). The previously approved Risk-Informed In-service Inspection (RI-ISI) program (Reference 1) will be substituted for Class 1 and Class 2 piping (Examination Categories B-F, B-J, C-F-1, C-F-2) in accordance with 10 CFR 50.55a(a)(3)(i) by alternatively providing an acceptable level of quality and safety. Other non-related portions of the ASME Section XI Code will be unaffected.

5.

Proposed Alternative and Basis for Use Pursuant to 10 CFR 50.55a(a)(3), NRC approval of the Susquehanna Alternate RI-ISI program as an alternative to the current 2007 Edition through the 2008 Addenda Edition, ASME Section XI inspection requirements for Class 1, Examination Category B-F and B-J, and Class 2, Examination Category C-F-1 and C-F-2 piping welds is requested.

The Susquehanna RI-ISI Program has been developed in accordance with the EPRI methodology contained in EPRI TR-112657, "Risk-Informed In-service Inspection Evaluation Procedure" (Reference 2). It was approved for use at Susquehanna during the first inspection period of the Third Ten-year Inspection Interval and is still applicable for the Fourth In-service Inspection Interval. The Susquehanna specific RI-ISI program is summarized in Tables 1 for Unit 1 and Table 2 for Unit 2 (Attachment 2). The RI-ISI

Inservice Inspection Program 10 CFR 50.55a Request 4RR-01 to PLA-7193 Page 4 of 18 program has been updated consistent with the intent of NEI-04-05 (Reference 3) and continues to meet EPRI TR -112657 and Regulatory Guide 1.17 4 risk acceptance criteria.

Susquehanna will continue to implement the Risk-Informed Inservice Inspection Program in accordance with ASME Code Case N-578-1, "Risk-Informed Requirements for Class 1, 2, and 3 Piping, Method B,Section XI, Division 1." The ultrasonic examination volume to be used based on degradation mechanism and component configuration will be the examination figures specified in Section 4 of EPRI TR -112657. The ultrasonic examination procedures, equipment, and personnel used to detect and size flaws in piping welds will be qualified by performance demonstration in accordance with ASME Section XI Appendix VIII, "Performance Demonstration for Ultrasonic Examination Systems."

The volumetric scanning will be in both the axial and circumferential directions to detect flaws in these orientations.

As part of the RI-ISI living program update, the delta risk assessment was re-evaluated and was determined to continue to meet the delta risk acceptance criteria of EPRI TR-112657. This update is based on the most recent Susquehanna PRA, which has been peer reviewed to Regulatory Guide 1.200, Rev 2 and updated accordingly. The PRA has been determined to be adequate for this application as described in Appendix A.

Pursuant to 10 CFR50.55a(a)(3)(i), relief is requested on the basis that the proposed alternative to continue using a RI-ISI Program would provide an acceptable level of quality and safety.

6.

Duration of Proposed Alternative Relief is requested for the Fourth Ten-Year Inspection Interval of the lSI Program, which was scheduled to begin on June 1, 2014 and end May 31, 2024.

7.

Precedent The NRC previously approved the Susquehanna Alternate RI-ISI Program in Reference 1.

Susquehanna considers both the plant and industry operating experience and updates the RI-ISI program during the re-evaluation process following each inspection period per our commitment in section 4 of our original relief request (Reference 4)

8.

Reference Inservice Inspection Program 10 CFR 50.55a Request 4RR-01 to PLA-7193 Page 5 of 18

1. USNRC Letter dated July 28, 2005, "Susquehanna Stearn Electric Station, Units 1 and 2, Third 10-year Inservice Inspection (lSI) Interval Program Plan (TAC Nos. MC1181 and MC1182)"

2. EPRI TR-112657, Electric Power Research Institute Report for Alternative Requirements of Risk-Informed In-service Inspection Evaluation Procedure, EPRI, Polo Alto, CA: 1999, Rev B-A.

3. NEI-04-05, "Living Program Guidance to Maintain Risk-Informed In-service inspection Programs for Nuclear Plant Piping Systems," dated April 2004.

4. PPL Letter PLA-5662, "Susquehanna Stearn Electric Station Proposed Third Ten-year Inservice Inspection Interval Inservice Inspection Program Plan for Susquehanna SES Units 1 and 2," dated September 16, 2003

Susquehanna Unit 1 Facility Operating License No. NPF-14 NRC Docket Nos. 50-387 to PLA-7193 Page 6 of 18 Table 1: SSES Unit 1 Inspection Location Selection Comparison between 1st RI-ISI Interval and New RI-ISI Interval by Risk Category Risk Failure Potential 1sT Approved RI-ISI Interval New RI-ISI Interval System*

Consequence Code Category Rank Weld Category Rank DMs Rank Weld Count RI-ISI Other Count RI-ISI Other CAC 4

Medium High None Low C-F-2 0

0 1

1 a

CAC 6

Low Medium None Low C-F-2 0

0 4

0 a

CRD 7

Low Low None Low C-F-1 37 0

37 0

cs 2

High High IGSCC Medium B-J 2

0 2

0 cs 2

High High TASCS Medium B-J 8

2 0

0 b

cs 4

Medium High None Low B-J,C-F-1 4

1 12 2

b cs 5

Medium Medium IGSCC Medium B-J 2

0 2

0 cs 6

Low Medium None Low B-J,C-F-1 177 0

177 0

cs 7

Low Low None Low C-F-1 6

0 6

0 FW 1

High High TASCS,FAC High B-J,C-F-1 42 6

44 11 c

FW 1

High High TASCS, TT, FAC High B-J,C-F-1 21 11 8

2 d

FW 1

High High FAC High B-J,C-F-1 33 0

34 0

e FW 3

High Medium TASCS,FAC High B-J 2

0 6

2 f

FW 3

High Medium TASCS, TT, FAC High C-F-1 1

1 4

2 g

FW 3

High Medium TT,FAC High C-F-1 0

0 1

0 h

FW 5

Medium Low TASCS,FAC High B-J 0

0 1

0 i

FW 5

Medium Low TASCS, TT, FAC High B-J 0

0 1

0 J

HPCI 4

Medium High None Low B-J,C-F-1 22 3

9 1

k HPCI 5

Medium Medium TT Medium C-F-1 24 3

3 1

1 HPCI 6

Low Medium None Low C-F-1 117 0

9 0

k

Risk Consequence System*

Rank Category Rank HPCI 6

Low Low HPCI 7

Low Low MS 1

High High MS 3

High Medium MS 4

Medium High MS 6

Low Medium RBCW 7

Low Low RCIC 1

High High RCIC 3

High Medium RCIC 5

Medium Low RCIC 5

Medium Medium RCIC 6

Low Low RCIC 7

Low Low RHR 2

High High RHR 2

High High RHR 2

High High RHR 2

High High RHR 2

High High RHR 2

High High RHR 4

Medium High RHR 5

Medium Medium RHR 5

Medium Medium Susquehanna Unit 1 Facility Operating License No. NPF-14 NRC Docket Nos. 50-387 to PLA-7193 Page 7 of 18 Failure Potential 18T Approved RI-ISI Interval New RI-ISI Interval Code Category Weld DMs Rank Weld Count RI-ISI Other Count RI-ISI Other TT Medium C-F-1 0

0 21 0

1 None Low B-J,C-F-1 0

0 121 0

k FAC High B-J,C-F-1 256 0

108 0

m, n,o FAC High B-J,C-F-1 20 0

120 0

m None Low B-J 0

0 4

1 n

None Low C-F-1 0

0 44 0

0 None Low C-F-2 0

0 5

0 a

FAC High B-J 18 0

13 0

p FAC High B-J 0

0 1

0 p

FAC High B-J 0

0 4

0 p

TT Medium C-F-1 28 3

0 0

q, r TT Medium C-F-1 1

0 27 0

q,r None Low C-F-1 52 0

54 0

q,r EC Medium C-F-1 12 3

0 0

s IGSCC Medium B-J 4

0 14 0

t TASCS Medium B-J 1

0 1

1 TASCS, IGSCC Medium B-J 10 4

0 0

t TASCS, TT Medium B-J 3

0 0

0 t

TT Medium B-J 1

0 4

1 t

None Low C-F-1 139 14 151 16 s

EC Medium C-F-1 6

1 0

0 s

IGSCC Medium B-J,C-F-1 23 0

16 0

S,X, W

Risk System*

Consequence Rank Category Rank RHR 5

Medium Medium RHR 5

Medium Medium RHR 5

Medium Medium RHR 6

Low Low RHR 6

Low Medium RHR 6

Low Low RHR 7

Low Low RPV-E 1

High High RPV-E 1

High High RPV-E 1

High High RPV-E 2

High High RPV-E 2

High High RPV-E 2

High High RPV-E 2

High High RPV-E 2

High High RPV-E 4

Medium High RR 2

High High RR 2

High High RR 4

Medium High RR 6

Low Medium RWCU 1

High High RWCU 2

High High Susquehanna Unit 1 Facility Operating License No. NPF-14 NRC Docket Nos. 50-387 to PLA-7193 Page 8 of 18 Failure Potential 18T Approved RI-ISI Interval New RI-ISI Interval Code Category Weld DMs Rank Weld Count RI-ISI Other Count RI-ISI Other IGSCC,EC Medium C-F-1 1

0 0

0 s

TASCS, IGSCC Medium B-J 4

1 0

0 v

TT Medium B-J 0

0 7

1 u

IGSCC Medium B-J 7

0 19 0

V, W,X None Low B-J,C-F-1 283 0

318 0

s, w TASCS, TT Medium B-J 7

0 0

0 u

None Low B-J,C-F-1 49 0

20 0

w TASCS, TT, CC, FAC High B-J 6

6 0

0 y

TASCS, CC, FAC High B-J 0

0 6

2 y

FAC High B-J 4

0 4

0 IGSCC Medium B-F,B-J 6

0 10 0

a a IGSCC, CC Medium B-F 11 0

1 0

z IGSCC, TT Medium B-J 0

0 10 3

z TASCS, IGSCC Medium B-F,B-J 4

4 0

0 a a TT Medium B-J 1

0 1

0 None Low B-J 10 1

10 1

IGSCC Medium B-J 60 0

60 0

TT Medium B-J 0

0 20 5

bb None Low B-J 79 8

52 6

bb,cc None Low B-J 0

0 7

0 cc FAC High B-J 55 0

60 0

dd,ee IGSCC Medium B-J 6

0 6

0

Susquehanna Unit 1 Facility Operating License No. NPF-14 NRC Docket Nos. 50-387 to PLA-7193 Page 9 of 18 Risk Failure Potential 1ST Approved RI-ISI Interval New RI-ISI Interval Consequence System*

Code Category Category Rank Rank DMs Rank Weld Count RI-ISI RWCU 3

High Medium FAC RWCU 4

Medium High None RWCU 6

Low Medium None SBLC 4

Medium High None SBLC 6

Low Medium None SBLC 7

Low Low None

• Acronyms defined:

CAC - Containment Atmosphere Control CRD-Control Rod Drive and Scram Discharge Volume CS - Core Spray DMs -Damage Mechanisms FW - Feed water HPCI-High Pressure Coolant Injection IGSCC-lntergranular Stress Corrosion Cracking MS - Main Steam RBCW-Reactor Building Closed Cooling Water RC -Reactor Coolant System High B-J 0

Low B-J 71 Low B-J 0

Low B-J 0

Low B-J 44 Low B-J 9

1789 RCIC -Reactor Core Isolation Cooling RHR-Residual Heat Removal System RI-ISI-Risk Informed Inservice Inspection RPV-E-Reactor Pressure Vessel RR - Reactor Recirculation RWCU-Reactor Water Cleanup SBLC-Standby Liquid Control T ASCs - Thermal Stratification TT - Thermal Transients Notes: (This table shows the systems that contain welds that are Class 1 or Class 2 category B-J, B-F, C-F-1, or C-F-2.)

a.

New system scope

b.

TASCS removed; 8 welds moved to RC 4 from RC 2 TASCS

c.

Two additional RC 1 TASCS, FAC welds from the following changes:

+18 from RC 1 TASCS, TT, FAC (TT removed)

-8 to RC 1 TASCS, TT, FAC (TT added)

-4 to RC 3 TASCS, FAC (consequence decrease)

-4 to RC3 TASCS, TT, FAC (consequence decrease and TT added) 0 8

0 0

0 0

80 Weld Other Count RI-ISI Other 1

0 ee 52 6

dd,ee 13 0

ee 10 1

ff 34 0

ff 9

0 1799 66

Susquehanna Unit 1 Facility Operating License No. NPF-14 NRC Docket Nos. 50-387

d.

Thirteen welds removed from RC 1 TASCS, TT, FAC for the following changes:

-18 to RC 1 TASCS, FAC (TT removed)

-2 to RC 1 FAC (TASCS, TT removed)

+8 from RC 1 TASCS, FAC (TT added)

-1 to RC 3 TASCS, FAC (consequence decrease)

e.

One weld added to RC 1 FAC from the following changes:

+2 from RC 1 TASCS, TT, FAC (TASCS, TT removed)

-1 to RC 3 TT, FAC (consequence decrease and TT added)

f.

Four welds added to RC 3 TASCS, FAC from the following changes:

+1 from RC 3 TASCS, TT, FAC (TT removed)

+4 from RC 1 TASCS, FAC (consequence decrease)

-1 to RC 5 TASCS, FAC (consequence decrease)

-1 to RC 5 TASCS, TT, FAC (consequence decrease and TT added)

+ 1 from RC 1 TASCS, TT, FAC (consequence decrease and TT removed)

g.

Three additional RC 3 TASCS, TT, FAC welds from the following changes:

-1 to RC 3 TASCS, FAC (TT removed)

+4 from RC 1 TACS, FAC (consequence decrease and TT added)

h.

One weld added to RC 3 TT, FAC from RC 1 FAC (consequence decrease and TT added)

i.

One weld added to RC 5 TASCS, FAC from RC 3 TASCS, FAC (consequence decrease)

j.

One weld added to RC 5 TASCS, TT, FAC from RC 3 TASCS, FAC (consequence decrease and TT added) to PLA-7193 Page 10 of 18

k.

Consequence decreased; 2 welds moved to RC 6 from RC 4; 11 welds moved to RC 7 from RC 4; 110 welds moved to RC 7 from RC 6

1.

Consequence decreased; 21 welds moved to RC 6 TT from RC 5 TT

m. Consequence decreased; 100 welds moved to RC 3 FAC from RC 1 FAC

n.

FAC removed; 4 welds moved to RC 4 from RC 1 FAC

o.

Consequence decreased & FAC removed; 44 welds moved to RC 6 from RC 1 FAC

p.

Consequence decreased:

1 weld moved to RC 3 F AC from RC 1 F AC 4 welds moved to RC 5 F AC from RC 1 F AC

q.

28 RC 5 TT welds moved as follows:

27 welds moved to RC 6 TT (consequence decrease) 1 weld moved to RC 7 None (consequence decrease and TT removed)

r.

Two additional RC 7 welds from the following changes:

+ 1 from RC 5 TT (consequence decrease and TT removed)

+ 1 from RC 6 TT (TT removed)

Susquehanna Unit 1 Facility Operating License No. NPF-14 NRC Docket Nos. 50-387

s.

EC removed:

12 welds moved to RC 4 from RC 2 EC 6 welds moved to RC 6 from RC 5 EC 1 weld moved to RC 5 IGSCC from RC 5 IGSCC, EC

t.

T ASCS removed:

10 welds moved to RC 2 IGSCC from RC 2 IGSCC, TASCS 3 welds moved to RC 2 TT from RC 2 TASCS, TT

u.

Consequence increased and TASCS removed; 7 welds moved to RC 5 TT from RC 6 TASCS, TT

v.

Consequence decreased and TASCS removed; 4 welds moved to RC 6 IGSCC from RC 5 TASCS, IGSCC

w. Consequence increased:

29 welds moved to RC 6 from RC 7 7 welds moved to RC 5 IGSCC from RC 6 IGSCC

x.

Consequence decreased; 15 welds moved to RC 6 IGSCC from RC 5 IGSCC

y.

TT removed; 6 welds moved to RC 1 TASCS, CC, FAC from RC 1 TASCS, TT, CC, FAC

z.

CC removed and TT added; 10 welds moved to RC 2 IGSCC, TT from RC 2 IGSCC, CC aa. TASCS removed; 4 welds moved to RC 2 IGSCC from RC 2 TASCS, IGSCC bb. TT added; 20 welds moved to RC 2 TT from RC 4 cc. Consequence decreased; 7 welds moved to RC 6 from RC 4 dd. F AC added:

6 welds moved to RC 1 FAC from RC 4 ee. Consequence decreased:

13 welds moved to RC 6 from RC 4 1 weld moved to RC 3 FAC from RC 1 FAC ff.

Consequence increased; 10 welds moved to RC 4 from RC 6 to PLA-7193 Page 11 of 18

Susquehanna Unit 2 Facility Operating License No NPF-22 NRC Docket Nos. 50-388 to PLA-7193 Page 12 of 18 Table 2: SSES Unit 2 Inspection Location Selection Comparison between 1st RI-ISI Interval and New RI-ISI Interval by Risk Category Risk Failure Potential 18T Approved RI-ISI Interval New RI-ISI Interval System*

Consequence Code Category Weld Category Rank Rank DMs Rank WeldConnt RI-ISI Other RI-ISI Other Count CAC 4

Medium High None Low C-F-2 0

0 1

1 a

CAC 6

Low Medium None Low C-F-2 0

0 4

0 a

CRD 7

Low Low None Low C-F-1 39 0

39 0

cs 2

High High IGSCC Medium B-J 2

0 2

0 cs 2

High High TASCS Medium B-J 7

2 0

0 b

cs 4

Medium High None Low B-J,C-F-1 5

1 12 2

b cs 5

Medium Medium IGSCC Medium B-J 2

0 2

0 cs 6

Low Medium None Low B-J,C-F-1 173 0

173 0

cs 7

Low Low None Low C-F-1 6

0 6

0 FW 1

High High TASCS,FAC High B-J,C-F-1 51 6

48 12 c

FW 1

High High TASCS, TT, FAC High B-J,C-F-1 24 14 8

2 d

FW 1

High High FAC High B-J,C-F-1 22 0

29 0

e FW 3

High Medium TASCS,FAC High B-J 2

0 6

2 f

FW 3

High Medium TASCS, TT, FAC High C-F-1 1

1 5

2 g

FW 3

High Medium FAC High C-F-1 0

0 1

0 h

FW 3

High Medium TT,FAC High C-F-1 0

0 1

0 i

FW 5

Medium Low TASCS,FAC High B-J 0

0 1

0 j

FW 5

Medium Low TASCS, TT, FAC High B-J 0

0 1

0 k

HPCI 4

Medium High None Low B-J,C-F-1 19 2

11 2

1 HPCI 5

Medium Medium TT Medium C-F-1 22 3

3 1

1 HPCI 6

Low Medium None Low C-F-1 Ill 0

8 0

1

Risk System*

Consequence Category Rank Rank HPCI 6

Low Low HPCI 7

Low Low MS 1

High High MS 3

High Medium MS 4

Medium High MS 6

Low Medium RBCW 7

Low Low RCIC 1

High High RCIC 3

High Medium RCIC 5

Medium Low RCIC 5

Medium Medium RCIC 6

Low Low RCIC 7

Low Low RHR 2

High High RHR 2

High High RHR 2

High High RHR 2

High High RHR 2

High High RHR 4

Medium High RHR 5

Medium Medium RHR 5

Medium Medium RHR 5

Medium Medium Susquehanna Unit 2 Facility Operating License No NPF-22 NRC Docket Nos. 50-388 to PLA-7193 Page 13 of 18 Failure Potential 1sT Approved RI-ISI Interval New RI-ISI Interval Code Category Weld DMs Rank Weld Count RI-ISI Other RI-ISI Other Count TT Medium C-F-1 0

0 19 0

1 None Low B-J,C-F-1 0

0 111 0

1 FAC High B-J,C-F-1 276 0

108 0

m,n,o FAC High B-J,C-F-1 21 0

137 0

m None Low B-J,C-F-1 0

0 5

1 n

None Low B-J,C-F-1 0

0 47 0

0 None Low C-F-2 0

0 5

0 a

FAC High B-J 18 0

13 0

p FAC High B-J 0

0 1

0 p

FAC High B-J 0

0 4

0 p

TT Medium C-F-1 24 3

1 1

p,q TT Medium C-F-1 0

0 22 0

p None Low C-F-1 67 0

68 0

q EC Medium C-F-1 10 2

0 0

r IGSCC Medium B-J 4

0 12 0

s TASCS, IGSCC Medium B-J 8

4 0

0 s

TASCS, TT Medium B-J 3

0 0

0 s

TT Medium B-J 1

0 4

1 s

None Low C-F-1 131 14 141 15 r

EC Medium C-F-1 7

0 0

0 r

EC, IGSCC Medium C-F-1 1

1 0

0 r

IGSCC Medium B-J,C-F-1 27 0

13 0

r, v

Risk System*

Consequence Category Rank Rank RHR 5

Medium Medium RHR 5

Medium Medium RHR 5

Medium Medium RHR 6

Low Low RHR 6

Low Medium RHR 7

Low Low RPV-E 1

High High RPV-E 1

High High RPV-E 1

High High RPV-E 2

High High RPV-E 2

High High RPV-E 2

High High RPV-E 2

High High RPV-E 2

High High RPV-E 4

Medium High RR 2

High High RR 2

High High RR 4

Medium High RR 6

Low Medium RWCU 1

High High RWCU 2

High High RWCU 3

High Medium Susquehanna Unit 2 Facility Operating License No NPF-22 NRC Docket Nos. 50-388 to PLA-7193 Page 14 of 18 Failure Potential 1sT Approved RI-ISI Interval New RI-ISI Interval Code Category Weld DMs Rank Weld Count RI-ISI Other RI-ISI Other Count TASCS, IGSCC Medium B-J 4

1 0

0 u

TASCS, TT Medium B-J 4

0 0

0 s, t TT Medium B-J 0

0 3

1 s

IGSCC Medium B-J 0

0 19 0

u,v None Low B-J,C-P-1 315 0

323 0

r, t None Low C-P-1 12 0

12 0

TASCS, TT, CC, PAC High B-J 6

6 0

0 w

TASCS, CC, PAC High B-J 0

0 6

2 w

PAC High B-J 4

0 4

0 CC,IGSCC Medium B-J 10 1

0 0

X IGSCC Medium B-J 7

0 11 0

y IGSCC, TT Medium B-J 0

0 10 3

X TASCS, IGSCC Medium B-J 4

3 0

0 y

TT Medium B-J 1

0 1

0 None Low B-J 10 1

10 1

IGSCC Medium B-J 62 0

64 0

z TT Medium B-J 0

0 20 5

a a None Low B-J 77 8

43 5

aa, bb None Low B-J 0

0 14 0

bb PAC High B-J 66 0

70 0

cc,dd IGSCC Medium B-J 6

0 6

0 PAC High B-J 0

0 1

0 dd

Susquehanna Unit 2 Facility Operating License No NPF-22 NRC Docket Nos. 50-388 to PLA-7193 Page 15 of 18 Risk Failure Potential 1sT Approved RI-ISI Interval New RI-ISI Interval Consequence System* Category Rank Rank DMs Rank Code Category Weld Count RI-ISI RWCU 4

Medium High None RWCU 6

Low Medium None SBLC 4

Medium High None SBLC 6

Low Medium None SBLC 7

Low Low None

• Acronyms defined:

CAC - Containment Atmosphere Control CRD - Control Rod Drive and Scram Discharge Volume CS - Core Spray DMs - Damage Mechanisms FW-Feed water HPCI-High Pressure Coolant Injection IGSCC - Intergranular Stress Corrosion Cracking MS - Main Steam RBCW-Reactor Building Closed Cooling Water RC-Reactor Coolant System Low B-J 65 Low B-J 0

Low B-J 0

Low B-J 35 Low B-J 6

1778 RCIC -Reactor Core Isolation Cooling RHR-Residual Heat Removal System RI-ISI-Risk Informed Inservice Inspection RPV-E-Reactor Pressure Vessel RR - Reactor Recirculation RWCU-Reactor Water Cleanup SBLC - Standby Liquid Control T ASCs-Thermal Stratification TT - Thermal Transients Notes: (This table shows the systems that contain welds that are Class 1 or Class 2 category B-J, B-F, C-F-1, or C-F-2.)

a.

New system scope

b.

TASCS removed; 7 welds moved to RC 4 from RC 2 TASCS.

c.

Three welds removed from RC 1 TASCS, FAC for the following changes:

+18 from RC 1 TASCS, TT, FAC (TT removed)

-8 to RC 1 TASCS, TT, FAC (TT added)

-11 to RC 1 FAC (TASCS removed)

+2 from RC 1 FAC (TASCS added)

-1 to RC 3 TASCS, TT, FAC (consequence decreased and TT added)

-3 to RC 3 TASCS, FAC (consequence decreased) 7 0

0 0

0 80 Weld Other RI-ISI Other Count 50 5

cc, dd 10 0

dd 6

1 ee 29 0

ee 6

0 1790 65

Susquehanna Unit 2 Facility Operating License No NPF-22 NRC Docket Nos. 50-388

d.

16 welds removed from RC 1 TASCS, TT, PAC for the following changes:

-18 to RC 1 TASCS, PAC (TT removed)

+8 from RC 1 TASCS, PAC (TT added)

-2 to RC 3 TASCS, PAC (consequence decreased and TT removed)

-4 to RC 3 TASCS, TT, PAC (consequence decreased)

e.

Seven welds added to RC 1 PAC for the following changes:

+11 from RC 1 TASCS, PAC (TASCS removed)

-2 to RC 1 TASCS, PAC (TASCS added)

-1 to RC 3 TT, PAC (consequence decreased and TT added)

-1 to RC 3 PAC (consequence decreased)

f.

Four welds added to RC 3 TASCS, PAC for the following changes:

+1 fromRC 3 TASCS, TT, PAC (TT removed)

-1 to RC 5 TASCS, TT, PAC (consequence decreased and TT added)

+2 from RC 1 TASCS, TT, PAC (consequence decreased and TT removed)

+3 from RC 1 TASCS, PAC (consequence decreased)

-1 to RC 5 TASCS, PAC (consequence decreased)

g.

Four welds added to RC 3 TASCS, TT, PAC for the following changes:

-1 to RC 3 TASCS, PAC (TT removed)

+1 from RC 1 TASCS, PAC (consequence decreased and TT added)

+4 from RC 1 TASCS, TT, PAC (consequence decreased)

h.

Consequence decreased; 1 weld moved to RC 3 PAC from RC 1 PAC

i.

Consequence decreased and TT added; 1 weld moved to RC 3 TT, PAC from RC 1 PAC

j.

Consequence decreased; 1 weld moved to RC 5 TASCS, PAC from RC 3 TASCS, PAC

k.

Consequence decreased and TT added; 1 weld moved to RC 5 TASCS, TT, PAC from RC 3 TT, PAC I.

Consequence decreased:

1 weld moved to RC 6 from RC 4 7 welds moved to RC 7 from RC 4 19 welds moved to RC 6 TT from RC 5 TT 104 welds moved to RC 7 from RC 6

m. Consequence decreased; 116 welds moved to RC 3 PAC from RC 1 PAC

n.

PAC removed; 5 welds moved to RC 4 from RC 1 PAC

o.

Consequence decreased and PAC removed; 47 welds moved to RC 6 from RC 1 PAC to PLA-7193 Page 16 of 18

Susquehanna Unit 2 Facility Operating License No NPF-22 NRC Docket Nos. 50-388

p.

Consequence decreased:

1 weld moved to RC 3 FAC from RC 1 FAC 4 welds moved to RC 5 FAC from RC 1 FAC 22 welds moved to RC 6 TT from RC 5 TT

q.

Consequence decreased and TT removed; 1 weld moved to RC 7 from RC 5 TT

r.

EC removed:

10 welds moved to RC 4 from RC 2 EC 1 weld moved to RC 5 IGSCC from RC 5 EC, IGSCC 7 welds moved to RC 6 from RC 5 EC

s.

TASCS removed:

8 welds moved to RC 2 IGSCC from RC 2 TASCS, IGSCC 3 welds moved to RC 2 TT from RC 2 TASCS, TT 3 welds moved to RC 5 TT from RC 5 TASCS, TT

t.

TASCS, TT removed; 1 weld moved to RC 6 from RC 5 TASCS, TT

u.

Consequence decreased and TASCS removed; 4 welds moved to RC 6 IGSCC from RC 5 TASCS, IGSCC

v.

Consequence decreased; 15 welds moved to RC 6 IGSCC from RC 5 IGSCC

w. TT removed; 6 welds moved to RC 1 TASCS, CC, FAC from RC 1 TASCS, TT, CC, FAC

x.

CC removed and TT added; 10 welds moved to RC 2 IGSCC, TT from RC 2 CC, IGSCC

y.

TASCS removed; 4 welds moved to RC 2 IGSCC from RC 2 TASCS, IGSCC

z.

Two welds added to scope, IGSCC assigned; 2 new welds in RC 2 IGSCC aa. TT assigned; 20 welds moved to RC 2 TT from RC 4 bb. Consequence decreased; 14 welds moved to RC 6 from RC 4 cc. FAC added:

5 welds moved to RC 1 FAC from RC 4 dd. Consequence decreased:

1 weld moved to RC 3 FAC from RC 1 FAC 10 welds moved to RC 6 from RC 4 ee. Consequence increased; 6 welds moved to RC 4 from RC 6 to PLA-7193 Page 17 of 18 to PLA-7193 Page 18 of 18 Susquehanna Steam Electric Station, Units 1 and 2 Facility Operating License NPF-14 and NPF-22 NRC Docket Nos. 50-387 and 388 Susquehanna PRA Summary The PRA has been updated to maintain current with the plant design and operation and to support peer review. An industry Peer Review was conducted in October 2012 and the PRA model used in this evaluation is based on the latest PRA model that has been updated to resolve the important findings from this review.

The PRA Technical Adequacy Assessment is included in Attachment 2. This includes the findings and an explanation of their resolution and model impacts.

The original RI-ISI and numerous other RI-ISI evaluations have concluded external events are not likely to impact the consequence ranking. This position is further supported by Section 2 of EPRI Report 1021467, "Nondestructive Evaluation: Probabilistic Risk Assessment Technical Adequacy Guidance for Risk-Informed In-Service Inspection Programs" which concludes that quantification of these events will not change the conclusions derived from the RI-lSI process. As a result, there is no need to further consider these events.

to PLA-7193 PRA Technical Adequacy Assessment to PLA-7193 Page 1 of 60 PRA TECHNICAL ADEQUACY ASSESSMENT TABLE OF CONTENTS 1.0 PRA TECHNICAL ADEQUACY........................................................................... 2 1.1 PRA Maintenance and Update........................................................................... 2 1.2 Identification of Parts of the PRA Not Meeting Capability Category II............ 3 1.3 PRA Impact from Internal Flooding................................................................... 3 1.4 Additional Peer Review Facts and Observations............................................... 4 2.0 EVALUATION OF EXTERNAL EVENTS........................................................... 4 3.0

SUMMARY

............................................................................................................... 4

4.0 REFERENCES

.......................................................................................................... 5 TABLE 1: SUPPORTING REQUIREMENTS NOT MEETING CAPABILITY CATEGORY II OR GREATER TABLE 2: SUPPORTING REQUIREMENTS MEETING CAPABILITY CATEGORY II OR GREATER WITH ASSOCIATED FACTS AND OBSERVATIONS Page 1

1.0 PRA Technical Adequacy to PLA-7193 Page 2 of 60 The JUL12R1 update to the Susquehanna PRA model is the most recent evaluation of the risk profile at Susquehanna for internal event challenges [Ref. 6]. The Susquehanna PRA model is highly detailed, including a wide variety of initiating events, modeled systems, operator actions, and common cause events. The PRA model quantification process used for the Susquehanna PRA is based on the event tree/fault tree methodology, which is a well-known methodology in the industry. PPL employs a structured approach to establishing and maintaining the technical adequacy and plant fidelity of the PRA model for both Susquehanna operating units. This approach includes both a proceduralized PRA maintenance and update process, and the use of self-assessments and independent peer reviews. The following information describes this approach as it applies to the Susquehanna PRA.

1.1 PRA Maintenance and Update The PPL PRA maintenance and update process ensures that the applicable PRA model remains an accurate reflection of the as-built and as-operated plants. This process is defined in PPL administrative procedure NDAP-QA-1002 [Ref. 5] and a subordinate implementing procedure. PPL procedure NFP-QA-201, "Internal Events At Power PRA Model Update and Configuration Control Process," delineates the responsibilities and guidelines for updating the full power internal events PRA model for Susquehanna Units 1 and 2 [Ref. 4]. The overall model update process, including NFP-QA-201, defines the process for implementing regularly scheduled and interim PRA model updates, for tracking issues identified as potentially affecting the PRA models (e.g., due to changes in the plant, errors or limitations identified in the model, industry operating experience), and for controlling the model and associated computer files. To ensure that the current PRA model remains an accurate reflection of the as-built, as-operated plants, the following activities are routinely performed:

o Design changes and procedure changes are reviewed for their impact on the PRA model.

o New engineering calculations and revisions to existing calculations are reviewed for their impact on the PRA model.

o Maintenance unavailabilities are captured, and their impact on CDF is assessed.

o Plant specific initiating event frequencies, failure rates, and maintenance unavailabilities are updated at least every 6 years.

In accordance with this guidance, regularly scheduled PRA model updates occur at least every six years with more frequent updates occurring based on the risk significance of permanent changes, initiating events, and failure data such that the PRA continues to adequately represent the as-built, as-operated plant.

PPL implemented the JUL12R1 update to the Susquehanna PRA in January 2014. This update incorporated resolution of comments received from the industry peer review of the Susquehanna PRA conducted in October 2012.

to PLA-7193 Page 3 of 60 1.2 Identification of Parts of the PRA Not Meeting Capability Category II PPL has had PRA Peer Reviews performed in 2003 and in 2012. The 2012 peer review was performed in October 2012 using the NEI 05-04 process, the ASME PRA Standard (ASME/ANS RA-Sa-2009) [Ref. 3], and Regulatory Guide 1.200, Revision 2 [Ref. 2]. The 2012 Susquehanna PRA Peer Review was a full-scope review of the technical elements of the internal events and internal flooding, at-power PRA.

The 2012 peer review resulted in 284 (89%) Supporting Requirements (SRs) meeting Capability Category II or higher, and 35 (11%) of the SRs not meeting Capability Category (CC) II or higher. Note that of the 35 SRs not meeting CCII or higher, 24 were associated with the internal flooding technical element. Therefore, excluding internal flooding, more than 95% of the SRs met CCII or higher. Table 1lists all the SRs that do not meet CCII or higher and lists the SR, Facts and Observations (F&Os) gap with Significance, Resolution, and PRA Model Impact.

The peer review model and documentation were revised as described in the "Resolution" column. The revised model has been renamed JUL12R1 [Ref. 6]. Upon completion of the JUL12R1 model, excluding the internal flooding SRs, there are only 4 SRs that do not meet CCII or higher (i.e., HR-C3, DA-C6, DA-C12, and DA-C13). Additionally, it is noteworthy that there were ten best practices provided by the peer review team indicating the high level of quality of the Susquehanna PRA model.

1.3 PRA Impact from Internal Flooding As noted in Table 1, several of the internal flooding SRs did not meet Category II requirements. However, internal flooding is not a significant contributor to CDF and LERF for Susquehanna. The PRA Quantification Summary Notebook [Ref. 6] lists internal flooding as contributing 4.6% to CDF and 1.9% to LERF and provides a comparison to Limerick Generating Station. Limerick is a very similar two-unit plant design but with the following notable hardware and operational differences.

Limerick has four EDGs per unit whereas Susquehanna has four shared EDGs.

Susquehanna has a spare 'E' EDG and also maintains the Blue Max portable DG.

Limerick has procedural direction to cross-tie the 4 kV buses to get power from available EDGs to the safeguard buses as needed.

Susquehanna does not inhibit ADS in non-ATWS scenarios whereas Limerick does direct inhibiting ADS in non-ATWS scenarios (both sites direct inhibiting ADS in ATWS scenarios).

ECCS pump cooling and ECCS room cooling are normally supplied by SW at Limerick with backup provided by ESW. ECCS pump and room cooling is only provided by ESW at Susquehanna.

Other than the major differences highlighted above, the sites are very similar. The two sites are dual unit sites and have General Electric BWR/4 reactors. Bechtel was the architect engineer for both sites and the two sites are similar architecturally. Therefore, to PLA-7193 Page 4 of 60 with the plant layouts being similar, similar internal flooding results can be expected.

Limerick's flooding contribution to CDF and LERF as 5.9% and 3.6% respectively, which is comparable to Susquehanna's flooding contribution. It should also be noted that Limerick had only a few flooding SRs not meeting Capability Category II [Ref. 7].

Based on this industry comparison and small contribution of internal flooding to overall CDF and LERF, the Susquehanna internal flooding PRA can be applied to support the 4th 10 year inspection interval based on code case N-578-1. While the JUL12R1 model supports this application, PPL is addressing internal flooding F&O's through a focused model update and industry peer review.

1.4 Additional Peer Review Facts and Observations Table 2 lists all the SRs meeting CC II or higher for which an F&O was written. Similar to Table 1, it also lists the SR, F&O gap with Significance, Resolution, and PRA Model Impact. As can be seen, all of the remaining facts and observations have been closed, or have otherwise been determined to have no or negligible impact on the PRA model results.

2.0 EVALUATION OF EXTERNAL EVENTS The original RI-ISI and numerous other RI-ISI evaluations have concluded external events are not likely to impact the consequence ranking. This position is further supported by Section 2 ofEPRI Report 1021467, "Nondestructive Evaluation:

Probabilistic Risk Assessment Technical Adequacy Guidance for Risk-Informed In-Service Inspection Programs" [Ref. 1] which concludes that quantification of these events will not change the conclusions derived from the RI-lSI process. As a result, there is no need to further consider these events.

3.0

SUMMARY

The Susquehanna PRA maintenance and update processes and technical capability evaluations described above provide a robust basis for concluding that the PRA is suitable for use in risk-informed processes such as this Risk-Informed lSI application.

4.0 REFERENCES

to PLA-7193 Page 5 of 60

[1]

EPRI Report 1021467-A, "Nondestructive Evaluation: Probabilistic Risk Assessment Technical Adequacy Guidance for Risk-Informed In-Service Inspection Programs,"

June 2012.

[2]

Regulatory Guide 1.200, "An Approach for Determining the Technical Adequacy of Probabilistic Risk Assessment Results for Risk Informed Activities," Revision 2, March 2009.

[3]

American Society of Mechanical Engineers, "Standard for Probabilistic Risk Assessment for Nuclear Power Plant Applications," (ASME RA-Sa-2009), Addenda to ASME/ANS RA-S-2008, "Standard for Level 1/Large Early Release Frequency Probabilistic Risk Assessment for Nuclear Power Plant Applications," February 2009.

[4]

NFP-QA-201, "Internal Events at Power PRA Model Update and Configuration Control Process," Rev. 0.

[5]

NDAP-QA-1002, "Maintenance and Update of the Susquehanna PRA," Rev. 1.

[6]

EC-RISK-1164, Rev. 0, "Summary Notebook for the JUL12R1 PRA Model."

[7]

Limerick Generating Station Units 1 and 2, License Amendment Request Supplemental Information, Proposed Changes to Technical Specifications Sections 3.5.1, 3.6.2.3, 3.7.1.1, 3.7.1.2, and 3.8.1.1 to Extend Allowed Outage Times, June 16,2010 (ML101670319).

to PLA-7193 Page 6 of 60 TABLEl SUPPORTING REQIDREMENTS NOT MEETING CAPABILITY CATEGORY II OR GREATER SUPPORTING F&O #,DESCRIPTION OF GAP, RESOLUTION REQUIREMENT AND SIGNIFICANCE IE-AS 4-4: It appears that some maintenance rule Each system had been (Met Cat I) systems may need to be evaluated in order evaluated but the to complete the systematic evaluation of documentation was not each system, including support systems, to specifically included.

assess the possibility of an initiating event Therefore, a occurring due to a failure of the system.

Maintenance Rule System Table and This is a finding because the SR requires Initiating Event that all systems must be evaluated.

evaluation was provided in new Section 2.8 of the The requirement is to perform a systematic IE Notebook evaluation of EACH system, including support systems, to assess the possibility of an initiating event occurring due to a failure of the system. Not all maintenance rule plant systems appear to be identified as having been evaluated.

IE-AS 6-29: A systematic approach to identify Additional discussion (Met Cat I) initiating events is documented in Section about loss of 13.8 and 2.4-5 and appears to be reasonably 4 kV transformers was complete. However, no discussion on the added to Section 2.4.5 of effects of a loss of a single 13.8/4.16 kv the IE Notebook to transformer was found in the initiating address this F&O.

events notebook.

Refer to Section 2.4 of the IE Notebook for systems reviewed. It appears that some maintenance rule systems may need to be evaluated and therefore it does not meet CCII. However, a qualitative evaluation was performed to determine the systems that cause initiating events, but some systems were not explicitly addressed.

This is a suggestion as discussions with Susquehanna PRA staff indicate that loss of a trnaformer would not result in a plant trip or need for a shutdown.

MODEL IMPACT None, gap has been closed for the JUL12Rl model.

None, gap has been closed for the JUL12Rl model.

TABLEl to PLA-7193 Page 7 of 60 SUPPORTING REQUIREMENTS NOT MEETING CAPABILITY CATEGORY II OR GREATER SUPPORTING F&O #,DESCRIPTION OF GAP, RESOLUTION MODEL REQUIREMENT AND SIGNIFICANCE IMPACT SC-AS 1-12: There was no evidence presented To address this F&O, a None, gap (Not Met) that would indicate that an evaluation was new section 2.1.17 was has been performed to determine if certain accident added to the event tree closed for sequences should be extended beyond 24 and success criteria the JUL12R1 hours. Such an evaluation should include:

notebookoutlining the model.

dominant considerations A) Instances where there will be an contributing to the 24 eventual depletion of finite inventory hour PRA mission time.

injection sources (RWST/CST).

The section also outlines those systems/equipment B) Justification for why room cooling with less than a 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> dependencies are not necessary for cases mission time.

where room temperatures will exceed equipment functionality or isolation temperatures after 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

C) Justification for not extending the mission times for systems that are required to support long term DHR beyond the 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> mark.

This is a finding because the SR is considered to be not met.

SC-AS 1-23: The EDG mission time is 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

Open item This open (Not Met)

This is conservative compared to many item is a plants which use the convolution integral provided method to justify a much shorter mission suggestion time. This is helpful for the improvement for possible of MSPI margin.

enhancement and does not This is a suggestion because it is a by itself modeling enhancement.

result in SC-AS not being met.

Therefore, there is no model impact to PLA-7193 Page 8 of60 TABLEl SUPPORTING REQUIREMENTS NOT MEETING CAPABILITY CATEGORY II OR GREATER SUPPORTING F&O #,DESCRIPTION OF GAP, RESOLUTION REQUIREMENT AND SIGNIFICANCE SC-AS 1-24: Since the failure to start and run for Per the peer review team (Not Met) 1st hour have been combined in the data, proposed resolution, the the fail to run events with a mission time existing data was of 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> actually give the PRA a reviewed. It was mission time of 25 hours2.893519e-4 days <br />0.00694 hours <br />4.133598e-5 weeks <br />9.5125e-6 months <br />.

determined and documented in the The treatment is conservative and adds a Component Data very small increase in the failure Notebookthat the use of probability, so it is presented as a 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> for the failure suggestion.

to run portion is slightly conservative and acceptable. Therefore, the total time represented is one hour for failure to start, and 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> for failure to run.

SY-C3 1-18: Plant specific sources of modeling All of the system (Not Met) uncertainty are also addressed in the notebook assumptions Summary Notebook Appendix D.

were reviewed for Related SRs However, there are only 4 candidate applicability as potential QU-E1 sources of uncertainty identified. Given the sources of model (Met Cat I/IIIID) large number of modeling assumptions in uncertainty. The large AS-C3 the system notebooks (28 in the RHR majority of the listed (Met Cat IIII/III) system notebook alone) a more thorough assumptions were DA-E3 evaluation of plant specific sources of determined to be (Met Cat I/IIIIII) uncertainty should be performed.

standard assumptions or HR-I3 fell under the umbrella of (Met Cat IIII/III)

This is a finding because it relates directly level of detail issues.

LE-F3 to a standard requirement.

The few remaining items (Met Cat IIII/III) were added to Table D-2 IE-D3 in Appendix D of the (Met Cat I/IIIIII)

Summary Notebook for SC-C3 further discussion.

(Met Cat I/IIIIII)

MODEL IMPACT Negligible as the model is slightly conservative as is. The gap has been closed for the JUL12R1 model None, gap has been closed for the JUL12R1 model.

to PLA-7193 Page 9 of60 TABLEl SUPPORTING REQUIREMENTS NOT MEETING CAPABILITY CATEGORY II OR GREATER SUPPORTING F&O #,DESCRIPTION OF GAP, RESOLUTION REQUIREMENT AND SIGNIFICANCE HR-B2 7-4: Table F-1 in Attachment F lists This item was (Not Met) identified pre-initiator HEP basic events determined to be a which include CCF basic events. However, documentation and section 4.1.2.1 of the Human Reliability terminology issue and Notebook, Systems Review, says that due the manner that SR HR-to staggered testing/maintenance practices, A3 redundant systems like components in different divisions are was treated in the HRA generally not susceptible to restoration notebook, specifically error and "common mode" errors are the systems review in screened. Common mode errors cannot be section 4.1.2.1.

screened in this manner. Typically a plant's work planning process that After further review, SR prohibits cross divisional maintenance HR-A3 identifies that during normal operations are typically not only single activities that in effect during plant shutdowns. The simultaneously disable modeling of pre-initiator HFEs needs to redundant trains or include activities that occur during plant diverse systems require shutdowns.

the development of events. Separate This is a finding because it is desired to procedures/maintenance not screen errors that can affect multiple acts on different trains of a redundant system or diverse divisions or systems systems.

(even if they are performed in an outage) are NOT required in the development of events.

The statement "Due to staggered testing/maintenance practices, like components in different divisions are generally not susceptible to restoration errors and

'common mode' errors are screened" is no longer applicable and was removed from the HRA notebook.

Therefore, the potential condition described in the peer review comment is no longer applicable.

MODEL IMPACT None, gap has been closed for the JUL12Rl model.

to PLA-7193 Page 10 of 60 TABLEl SUPPORTING REQUIREMENTS NOT MEETING CAPABILITY CATEGORY II OR GREATER SUPPORTING F &0 #, DESCRIPTION OF GAP, RESOLUTION REQUIREMENT AND SIGNIFICANCE HR-C3 7-1: Section 4.1.2.1 of the HRA Notebook Open item (Not Met) provides guidance towards the identification of restoration errors and rniscalibration errors. In As indicated in the the subsection for Identifi<;ation of finding discussion from Miscalibration Errors, Item 4 says: Identify NUREG-1792, I&C components the rniscalibration of which "Generally, unless the will impact redundant system trains or redundant system components. Miscalibrations failure can effect that impact a single component may be multiple items, either screened from further consideration. The missing the failure or Susquehanna HRA analysis assumes that double-counting the rniscalibration is included in the component failure have small effects failure rate data. However rniscalibrations are on the outcome of the not included in the failure rate data of PRA." Therefore, NUREG-6928 and therefore there are potential adding this level of detail failures that may have an adverse impact on for single component equipment that has not been assessed in the miscalibration events is Susquehanna HRA.

not warranted. The HRA Further in Section 4.1.4 of NUREG-1792, documentation clarifies Good Practices for Implementing Human that these events are not Reliability Analysis (HRA) it says:

included because they In practice it is best to include pre-initiator are low contributors.

human actions even if the associated failure When this issue is fully already may be included in the failure data for addressed, it may be the affected equipment item (e.g., in the possible to use SR SY-failure-to-start data). This is because it is often A15 to demonstration hard to determine if the failure databases that single sensor include such human failures since data bases are typically insufficiently documented to miscalibrations can be know if the potential pre-initiator failure is excluded.

already included. Generally, unless the failure can affect multiple equipment items, either missing the failure or double-counting the failure have small effects on the outcome of the PRA. Potential double-counting is the most conservative approach and yet typically does not result in a serious overestimation of the failure's significance. In addition, including all identified pre-initiators gives analysts the opportunity to identify the significance of potentially problematic actions such as those with procedural or training problems, those that do not require appropriate checks, etc.

This is a finding. The impacts of rniscalibration must be included as a mode of failure of initiation of standby systems and cannot be screened.

MODEL IMPACT Negligible effect on model results as per the provided resolution.

TABLEt to PLA-7193 Page 11 of 60 SUPPORTING REQUIREMENTS NOT MEETING CAPABILITY CATEGORY II OR GREATER SUPPORTING F&O #,DESCRIPTION OF GAP, RESOLUTION MODEL REQUIREMENT AND SIGNIFICANCE IMPACT HR-Fl 1-2: There are few HRA events that are Redefined the risk None, gap (Not Met) grouped together into a single HFE.

significant MAN-has been However, the most risk significant OP _SPC _INJ _L-0 into closed for Related SRs example is MANOP _SPC_INJ_L-0. This three new HEPs MAN-the JUL12R1 HR-G3 event represents the opening of several OP_SPC_E-0, MAN-model.

(Met Cat II & III) valves related to the SPC function. The OP _SPC_L-0, and degree of difficulty of opening these MAN-OP _INJ_L-0, and valves is not necessarily the same nor are performed detailed the performance shaping factors. There is evaluations for each.

little documentation in the HRA documentation or HRA calculator to justify this grouping. Also, the value for this HRA grouping appears to be extremely low for an in-field operator action (6.9E-4).

This is a finding because this issue causes the SR HR-F1 to be 'Not Met.'

HR-Fl 1-3: For HRA MAN-OP _SPC_INJ_L-0, Detailed timing None, gap (Not Met) there is no analysis of how many "turns" evaluation added as part has been that it takes to manually operate the valves of the evaluation of the closed for that are to be operated. The valves within new HEPs MAN-the JUL12R1 this grouped HEP are within large OP _SPC_E-0, MAN-model.

diameter piping segments with varying OP _SPC_L-0, and diameters and stroke characteristics. These MAN-OP _INJ_L-0.

characteristics can significantly affect the References were added manipulation time.

to the Timing and Assumptions sections of This is a finding, since it directly involves the three MAN-OP the manipulation time evaluation of a risk calculations in the HRA significant operator action.

notebook.

to PLA-7193 Page 12 of 60 TABLEl SUPPORTING REQUIREMENTS NOT MEETING CAPABILITY CATEGORY II OR GREATER SUPPORTING F &0 #, DESCRIPTION OF GAP, RESOLUTION REQUIREMENT AND SIGNIFICANCE HR-G6 7-9: While Table 5.1-2 does lists the actions by Added text to Section 5.1 (Not Met) decreasing HEP value and includes comparison to explain that the Table comments execution location, execution stress, 5.1-2 actions were listed performance shaping factors, timing (along with their information, the comparison comments are individual details) in really directed more towards an internal decreasing HEP order in assessment of the HFE itself, rather than it's comparison between events that have a similar order to facilitate HEP. However, the standard requires that a comparison between check of HEP values relative to each other be actions with similar performed. It does not appear that this was HEPs. Inconsistencies done. This is evidenced by the fact that there were identified and are some local actions (with potentially corrected as needed.

negative performance shaping factors and There are some local lower likelihood of success) that have HEP actions, as noted by the values roughly equal to those of a similar in reviewer, with control room action. Examples of this include potentially negative 159-CNTVNT-0 and 159-CNTVNTLOCAL-0, as well as MAN-OP _SPC_INJ_L-0 performance shaping compared to other control room actions).

factors that have HEP values roughly equal to Further, there is no discussion to relate those of control room location; timing, PSFs, etc. relative to each actions, but the similarity other and the values within a HFE range are is justified in the highly variable.

comments section by It is understood that the intent of this standard stating that the time is to assess the HFEs relative to each other, i.e., available for recovery for for all of the HFEs that fall within a specific the ex-MCR action range, is the expected failure rate of the would allow multiple operators considered reasonable? For example, execution attempts and are all of the events that have a 1E-1 recovery opportumtles.

probability considered more difficult than the HFEs that have probabilities in the lE-2 range?

Similarly all of the HFE's that have probabilities on the lE-3 range should be generally considered to have the same level of difficulties compared to the ones in the lE-2 range.

This is a finding because it is not apparent a comparison of events of like values, i.e., those with similar HEPs, has been conducted.

MODEL IMPACT None, gap has been closed for the JUL12R1 model.

to PLA-7193 Page 13 of 60 TABLE1 SUPPORTING REQIDREMENTS NOT MEETING CAPABILITY CATEGORY II OR GREATER SUPPORTING F&O #,DESCRIPTION OF GAP, RESOLUTION REQUIREMENT AND SIGNIFICANCE DA-C6 4-9: As shown in Attachment Band Tables Open item (Not Met)

B-8 and B-9 of the Component Data Notebook, most estimated demands were Related SRs determined from the MSPI and from plant DA-C7 experience. However, there is no (Cat II/III met) documentation that it is collected in accordance with the requirements of this SR.

This is a finding. The basis for collection of plant failure data is not provided except to indicate that the source was from MSPI data.

DA-C12 4-12: No evidence was found that the Open item (Not Met) unavailability data obtained from MSPI was evaluated for issues of "double DA-C13 counting."

(Not Met)

Also, there was no consideration given to the handling of unavailability hours that occurred online versus during an outage.

This is a finding because there was no evidence found that this requirement was considered.

MODEL IMPACT Negligible effect on model results. This F&O cites a lack of documentati on that the estimated demands were collected in accordance with the SR.

Documentati on item.

Negligible effect on model results.

MSPI unavailabilty data is by it's own program considered for reactor

'critical' hours.

Unkown potential

'double counting' of MSPidata would be slightly conservative.

TABLEl to PLA-7193 Page 14 of 60 SUPPORTING REQIDREMENTS NOT MEETING CAPABILITY CATEGORY II OR GREATER SUPPORTING F &0 #, DESCRIPTION OF GAP, RESOLUTION MODEL REQUIREMENT AND SIGNIFICANCE IMPACT QU-D4 5-7: No evidence of a comparison of CDF Attachment F was added None, gap (Met Cat I) and LERF results with similar plants was to the quantification and has been found in the documentation. CC-II requires summary notebook closed for Related SRs this comparison and identification of which includes a detailed the JUL12Rl LE-F2 causes for significant differences.

comparison of the CDF model.

(Met Cat I/IIIIII) and LERF results with This is a finding because it causes QU-D4 Limerick. Limerick has to be a Cat I.

been considered a sister plant to Susquehanna and is a very similar two unit BWR GE design site. The comparison results were similar and reasonable.

IFSO-Al 6-2: Per discussion in Section B.2.1, a Open item Negligible (Not Met) rupture of fire protection piping appears to effect on be screened from further analysis, except model IFSN-A16 in a few select areas. The given basis for results. See (Not Met) this is that a fire protection rupture would PRA Impact be quickly identified, diagnosed, and from Internal Related SRs isolated. However, it may not be an Flooding IFSO-A3 insignificant amount of time for operations discussion, (Not Met) to diagnose that a flood is occurring, rather which than a fire. Once the flood condition is precedes IFSN-AlO identified, it may take further time to Table 1.

(Not Met) isolate the flood (typically not able to simply stop the pump in the control room, IFSN-A14 but rather it must be shut down locally). It (Not Met) is possible for a significant amount of flooding to occur during this time period.

IFSN-A15 While some flood scenarios are included in (Not Met) the analysis, it is unclear what criteria was used as to whether or not fire protection IFQU-A5 piping was excluded in a given area, and (Not Met) how much total fire protection piping was excluded.

IFQU-B3 (Not Met)

This is a finding because fire protection piping does not appear to be adequately addressed in the analysis. Floods resulting from fire protection piping ruptures can be significant contributors to CDF.

to PLA-7193 Page 15 of 60 TABLEl SUPPORTING REQUIREMENTS NOT MEETING CAPABILITY CATEGORY II OR GREATER SUPPORTING F&O #,DESCRIPTION OF GAP, RESOLUTION REQUIREMENT AND SIGNIFICANCE IFSO-Al 6-3: Section 2.2.11 indicates that lagged Open item (Not Met) and insulted piping was not considered as a spray source. There does not appear to be any justification for this assumption, and it is typically not used for industry IFPRAs.

Furthermore, it is unclear from the documentation if spray effects from fire piping is included or not, based on the discussions in Section B.2.1 about excluding fire piping. Based on discussions with site and contractor personnel, a calculation was produced to demonstrate that lagged piping could not result in a spray impact. Furthermore, there are very few, if any, cases of insulated piping that is not also lagged. Finally, it was confirmed that fire protection piping was considered as a spray source.

This is a suggestion to enhance the documentation.

IFSO-Al 6-4: Flood sources appear to be based on Open item.

(Not Met) building elevations rather than individual flood areas.

This is a finding as this SR requires flood sources to be identified on a flood area basis.

MODEL IMPACT Document-ation item.

No impact Negligible effect on model results. See PRA Impact from Internal Flooding discussion, which precedes Table 1.

to PLA-7193 Page 16 of 60 TABLEt SUPPORTING REQUIREMENTS NOT MEETING CAPABILITY CATEGORY II OR GREATER SUPPORTING F&O #,DESCRIPTION OF GAP, RESOLUTION REQUIREMENT AND SIGNIFICANCE IFSO-Al 1-35: There is no evidence that a search for Open item.

(Not Met) sources of flooding on the upper level of the control structure (where chiller units An interim walkdown Related SRs and service water piping is located) which was performed in and IFSN-A8 could cause flooding of the control room, around the class 1E (Met Cat II) battery rooms, and/or relay rooms via battery and DC propagation through ductwork was distribution panel areas considered in the analysis. Susquehanna in the Control Structure.

personnel looked at drawings during the No ductwork was located Peer Review and found no evidence of in the immediate vicintiy such a scenario. However, this should be of class 1E batteries, confirmed by a walkdown.

chargers, or distribution panels such that direct This is a suggestion, since there is no spray or deluge would evidence based upon Susquehanna cause inoperability.

evaluation during the Peer Review that this is a plausible scenario.

IFSO-Al 6-41: Section 3.4 of the Internal Flooding Open item (Not Met) notebook indicates that only >6 in (and in some cases >4 in) piping was considered IFSO-A3 for flood scenarios, and it appears that (Not Met) smaller diameter piping (in general) was not considered.

IFSN-A15 (Not Met)

Flood scenarios have been developed and are listed in Appendix C, and in Table 4-1 Related SRs of Attachment E, of the Internal Flooding IFSN-AlO notebook.

(Not Met)

However, given the number of inappropriately screened flood sources, a significant number of potential flood scenarios have likely been missed in this analysis.

This is a finding as potential flood sources may have been missed or not appropriately assessed, which causes several SRs to be "Not Met."

MODEL IMPACT Documentati on item. No impact.

The identified gap is a suggestion to provide additonal documentati on supporting the investigation s perfromed during the peer review and additional walkdown.

Negligible effect on model results. See PRA Impact from Internal Flooding discussion, which precedes Table 1.

to PLA-7193 Page 17 of 60 TABLE I SUPPORTING REQUIREMENTS NOT MEETING CAPABILITY CATEGORY II OR GREATER SUPPORTING F&O #,DESCRIPTION OF GAP, RESOLUTION REQUIREMENT AND SIGNIFICANCE IFSO-A4 6-5: Failure modes of components appears Open item (Not Met) to be included in the pipe rupture data used, as discussed in Section 2.2.9 of the Internal Flooding Notebook. Maintenance events are also assumed to be captured in this data (see also discussion in Section 3.7 of Attachment E). Inadvertent actuation of fire suppression system is discussed in Section B.2.

While a review of industry OE was performed for maintenance induced flooding, no plant -specific review is documented. Furthermore, no review of plant test and maintenance procedures to identify potential errors resulting in a flood appears to have been performed.

This is a finding as the plant -specific potential for maintenance-induced flooding does not appear to be appropriately addressed.

IFSO-AS 6-6: The Reg Guide 1.200 Clarification Open item (Not Met) states that a range of flow rates must be considered. This analysis considers only

'worst case' failure scenarios.

This is a finding as a range of flow rates is required per the Reg Guide 1.200 clarification.

MODEL IMPACT Negligible effect on model results. See PRA Impact from Internal Flooding discussion, which precedes Table 1.

Negligible effect on model results.

Bounding larger break flooding effects are considered in the model.

SeePRA Impact from Internal Flooding discussion, which precedes Table 1.

TABLEl to PLA-7193 Page 18 of 60 SUPPORTING REQUIREMENTS NOT MEETING CAPABILITY CATEGORY II OR GREATER SUPPORTING F &0 #, DESCRIPTION OF GAP, RESOLUTION MODEL REQUIREMENT AND SIGNIFICANCE IMPACT IF SO-AS 6-7: Pressure and temperature information Open item Negligible (Not Met) for flood sources was not found in the effect on documentation.

model results. See This is a finding as pressure and PRA Impact temperature information is not included in from Internal the Internal Flooding Analysis.

Flooding discussion, which precedes Table 1.

IFSO-B3 6-20: Assumptions are discussed in Open item Documen-(Not Met)

Section 2.2 of the Internal Flooding tation item.

documentation. Discussion of uncertainty IFSN-B3 appears limited to discussion of flood Negligible (Not Met) initiator frequencies. Attachment D effect on includes discussion of pipe failure modes model IFEV-B3 but no other discussion of uncertainty is results. See (Not Met) identified. No documentation exists for PRA Impact impacts of various assumptions on model from Internal IFQU-B3 uncertainty could be found.

Flooding (Not Met) discussion, This is a finding as the SR requires a which Related SRs discussion of model uncertainty.

precedes IFPP-B3 Table 1.

(Met Cat IIIIIIII) to PLA-7193 Page 19 of 60 TABLEl SUPPORTING REQIDREMENTS NOT MEETING CAPABILITY CATEGORY II OR GREATER SUPPORTING F&O #,DESCRIPTION OF GAP, RESOLUTION REQUIREMENT AND SIGNIFICANCE IFSN-A3 6-9: Automatic and Operator actions Open item (Not Met) appear to be identified throughout the notes in Appendix C, as well as the IFSN-A14 discussion in Section B. However, (Not Met) numerous concerns exist with the approach taken, as discussed below. There appears IFQU-AS to be no justification/basis for crediting (Not Met) these actions.

For example, a flood in C-604 (page C.2 credits operator action to isolate a domestic water pipe rupture prior to equipment damage. What indication exists to alert operations of the flood prior to the occurrence of equipment damage?

Furthermore, no consideration is given to the likelihood of operator failure/in-action.

This is a finding since while operator actions are credited to terminate flooding before equipment damage occurs, there appears to be insufficient basis for crediting these actions. This may result in erroneously screening some scenarios, which is non-conservative.

IFSN-A3 6-10: Section 4.2 states that no mitigation Open item (Not Met) actions credited to limit the impacts from a flood. However, the comments contained Related SRs in Appendix C do appear to credit operator IFQU-A5 action (as well as discussion in Section (Not Met)

B.2.1 to isolate fire protection piping).

This text is confusing/incorrect.

This is a suggestion because it only pertains to documentation and is not an unanalyzed method.

MODEL IMPACT Negligible effect on model results. See PRA Impact from Internal Flooding discussion, which precedes Table 1.

Document-ation item.

No impact to PLA-7193 Page 20 of60 TABLEt SUPPORTING REQUIREMENTS NOT MEETING CAPABILITY CATEGORY II OR GREATER SUPPORTING F&O #,DESCRIPTION OF GAP, RESOLUTION REQUIREMENT AND SIGNIFICANCE IFSN-A6 6-14: Susceptibility of SSCs to flood Open item (Not Met) damage is discussed in Section 2.2 of the Internal Flood notebook. This discussion IFQU-A9 includes spray and submergence (Not Met) considerations. A qualitative discussion of additional impacts (jet impingement, pipe whip, humidity) is required for CC IIII per Reg Guide 1.200 clarification, but is not included here.

Since medium and small bore fire protection piping is dismissed from the analysis and since spray sources greater than 10 feet away from the source are typically dismissed, the effects of pipe whip and jet impingement cannot be said to be evaluated in the quantification.

This is a finding. A qualitative discussion of additional impacts (jet impingement, pipe whip, humidity) is required for CC IIII per Reg Guide 1.200 clarification to meet SR IFSN-A6. An evaluation of medium/small bore piping for pipe whip and jet impingement is required to meet SRIFQU-A9.

IFSN-AlO 6-42: Flood scenarios have been developed Open item (Not Met) and are listed in Appendix C, and in Table 4-1 of Attachment E, of the Internal Related SRs Flooding notebook.

IFSN-A5 (Met Cat IIIIIIII)

There does not appear to be any consideration to the impact of water intrusion on control panels or junction boxes. This can result in additional failures to PRA-credited equipment that is otherwise not impacted by the flood.

This is a finding as some potential failure modes (grounding of local control panels or junction boxes) were not considered in the analysis.

MODEL IMPACT Negligible effect on model results. See PRA Impact from Internal Flooding discussion, which precedes Table 1.

Negligible effect on model results. See PRA Impact from Internal Flooding discussion, which precedes Table 1.

to PLA-7193 Page 21 of 60 TABLEl SUPPORTING REQillREMENTS NOT MEETING CAPABILITY CATEGORY II OR GREATER SUPPORTING F&O #,DESCRIPTION OF GAP, RESOLUTION REQUIREMENT AND SIGNIFICANCE IFSN-A13 6-17: Per Section 3.3.5 and Appendix E of Open item (Not Met) the Internal Flooding documentation, flood areas were screened if no scram or 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> shutdown was required OR no significant source of water exists in the room.

This is not sufficient per the standard.

This is a finding since it causes the associated SR to be not met.

IFSN-A17 1-40: Credited plant walkdowns were Open item (Not Met) conducted at various times and were separated by a period of many years. There IFQU-All was not a systematic walkdown plan that (Not Met) was applied to this process and thus the requisite information could not be gleaned Related SRs to form the basis for scenario IFSO-A6 development. Walkdowns were deemed to (Met Cat 1111/IIl) not be complete with respect to their evaluation of flood-induced HRA and IFQU-B2 (implicit or explicit) screening decisions.

(Met Cat 1111/IIl)

This is a finding because it causes SRs to be not met.

IFSN-A17 4-17: Qualitative screening of areas is Open item (Not Met) discussed in Appendices B and C of the Internal Flood notebook. Flood areas Related SRs appear to screened on the basis of either no IFSN-A12 significant flood sources or no mitigation (Met Cat 1111/IIl) equipment is present in the flood area.

However, except for Table 4-1 for IFSN-B1 unscreened flood areas, sufficient (Met Cat 1111/IIl) information is not provided to determine which SSCs are in each flood area and what flood heights or spray considerations should have been included.

This is a suggestion since it involves documentation. There is insufficient information provided about the SSCs in each flood area.

MODEL IMPACT Negligible effect on model results. See PRAimpact from Internal Flooding discussion, which precedes Table 1.

Negligible effect on model results. See PRA Impact from Internal Flooding discussion, which precedes Table 1.

Document-ation item.

No impact to PLA-7193 Page 22 of 60 TABLEt SUPPORTING REQIDREMENTS NOT MEETING CAPABILITY CATEGORY II OR GREATER SUPPORTING F&O #,DESCRIPTION OF GAP, RESOLUTION REQUIREMENT AND SIGNIFICANCE IFSN-B2 6-18: The Internal Flooding notebook Open item (Not Met) discusses propagation pathways, accident mitigation features, assumptions and calculations, flood scenarios considered, screened, and retained, and results of plant walkdowns.

No information was found regarding listing of SSCs in each flood area, height of floor, vulnerability to spray, etc.

This is a finding as information used in the analysis is not clearly referenced to verify accuracy.

IFSN-B2 6-19: The Internal Flooding notebook Open item (Not Met) discusses propagation pathways, accident mitigation features, assumptions and Related SRs calculations, flood scenarios considered, IFSO-B2 screened, and retained, and results of plant (Met Cat IIIIIIII) walkdowns.

Only limited information was found regarding pipe lengths, diameters, insulation, etc.

This is a finding as piping information is required to verify the results of the assessment, including max flow rate and pipe rupture frequencies.

MODEL IMPACT Negligible effect on model results. See PRA Impact from Internal Flooding discussion, which precedes Table 1.

Negligible effect on model results. See PRA Impact from Internal Flooding discussion, which precedes Table 1.

to PLA-7193 Page 23 of60 TABLEl SUPPORTING REQIDREMENTS NOT MEETING CAPABILITY CATEGORY II OR GREATER SUPPORTING F &0 #, DESCRIPTION OF GAP, RESOLUTION REQUIREMENT AND SIGNIFICANCE IFSN-B2 6-8: Presence of alarms is discussed in Open item (Not Met) individual room analysis in Appendix B of Internal Flooding notebook. Curbs, drains, Related SRs sump pumps, etc. appear to be accounted IFSN-A2 for in calculations in Appendix C.

(Met Cat I/IJJIII)

Appendix D lists all water tight doors in plant.

Lists/tables of such features in each plant area would aid in review, as well as walkdown verification.

This is a suggestion since while the required information appears to be incorporated in the analysis, including lists of such features for each flood area would be beneficial for review.

IFSN-B2 6-12: Drains/sumps are discussed Open item (Not Met) throughout the documentation, but no indication of drain size or sump pump Related SRs capacity was found. Drains were not IFSN-A4 credited in hydraulic calculations. The (Met Cat I/IJJIII) presence of drains/sumps was credited to screen out some flood scenarios with low volume sources in Appendix C.

The presence of curbs appears to be included in hydraulic calculations.

This is a suggestion as floor drains and sumps typically do not have a major impact on flood scenarios.

IFSN-B2 6-13: Table 4-1 of Attachment E ofthe Open item (Not Met)

Internal Flooding notebook documents the impacted SSCs.

Related SRs IFSN-A5 However, it is not always clear what the (Met Cat I/II/III) impacted components are, as often times only the System (e.g., RBCCW or HPCI) is identified.

This is a suggestion as it should not impact the results of the model.

MODEL IMPACT Document-ation item.

No impact.

Negligible effect on model results. See PRAimpact from Internal Flooding discussion, which precedes Table 1.

Negligible effect on model results. See PRA Impact from Internal Flooding discussion, which precedes Table 1.

TABLEt to PLA-7193 Page 24 of 60 SUPPORTING REQUIREMENTS NOT MEETING CAPABILITY CATEGORY II OR GREATER SUPPORTING F&O #,DESCRIPTION OF GAP, RESOLUTION MODEL REQUIREMENT AND SIGNIFICANCE IMPACT IFEV-Al 4-14: Per Section B of Internal Flooding Open item Negligible (Not Met) notebook, flood scenarios are mapped to effect on existing plant initiators or are treated as model new initiators. However, flood-induced results. See LOCAs were not considered a credible PRA Impact event and were excluded from from Internal consideration LOCAs were addressed in Flooding the Initiating Events notebook.

discussion, which This is a finding since the potential for precedes flood-induced LOCAs was not included.

Table 1.

IFEV-A5 1-42: The pipe rupture frequencies used Open item Negligible (Not Met) for development of the flood initiating effect on event frequencies did not use the latest model data (published in November 2010). Since results. See the Internal Flooding Analysis was PRA Impact updated in early 2012, it was expected that from Internal justification would be provided to show Flooding that not using latest industry frequency discussion, data complies with the requirements.

which Therefore this SR is not met.

precedes Table 1.

This is a finding since it causes the SR to be "Not Met."

IFEV-A6 1-41: No consideration of material Open item Negligible (Met Cat I) condition, water hammer, or maintenance effect on induced flooding is included in the model analysis.

results. See PRA Impact This is finding since it causes the SR to be from Internal of Cat I only.

Flooding discussion, which precedes Table 1.

to PLA-7193 Page 25 of60 TABLEl SUPPORTING REQUIREMENTS NOT MEETING CAPABILITY CATEGORY II OR GREATER SUPPORTING F&O #,DESCRIPTION OF GAP, RESOLUTION REQUIREMENT AND SIGNIFICANCE IFQU-A6 1-30: There are some flooding events Open item (Not Met) which cause flooding of areas without the potential for draining the area in greater than four hours. Therefore, this screening criterion is questionable.

This is a finding because it causes the SR to be "Not Met."

IFQU-A6 1-31: There was no consideration given for Open item (Not Met) increased stress level for both in control room actions and ex -control room actions that were are not failed by the flooding scenario. There was no adjustment of HEPs related to this finding.

This is a finding because it causes the SR to be not met.

MODEL IMPACT Negligible effect on model results. See PRAimpact from Internal Flooding discussion, which precedes Table 1.

Negligible effect on model results. See PRAimpact from Internal Flooding discussion, which precedes Table 1.

to PLA-7193 Page 26 of 60 1.3 ADDITIONAL PEER REVIEW FACTS AND OBSERVATIONS Table 2 lists all the SRs meeting CC II or higher for which an F&O was written. Similar to Table 1, it also lists the SR, F&O gap with Significance, Resolution, and PRA Model Impact. As can be seen, all of the remaining facts and observations have been closed, or have otherwise been determined to have no or negligible impact on the PRA model results.

TABLE2 to PLA-7193 Page 27 of 60 SUPPORTING REQUIRElVIENTS lVIEETING CAPABILITY CATEGORY II OR GREATER WITH ASSOCIATED FACTS AND OBSERVATIONS SUPPORTING F &0 #, DESCRIPTION OF RESOLUTION IMPACT REQUIREMENT GAP, AND SIGNIFICANCE lE-Al 4-2: The Manual Shutdown initiator At power conditions for the None, gap has (Met Cat IIIIIIII) for 'unplanned events' was included in online PRA risk model is been closed for the the model even though section 2.3.4 defined to be plant modes 1, 2, JUL12Rl model.

clearly states that 'the scope of the PSA and 3. Supporting Requirement is for at-power conditions'.

IE-AI states to "Identify those This F&O is a suggestion.

initiating events that challenge Planned shutdowns that do not result normal plant operation and that in failures that would cause an require successful mitigation to initiating event would not challenge prevent core damage using plant safety and would not result in an structured, systematic process LER. Therefore, it should not be for identifying initiating events counted as an initiating event. The that accounts for plant specific current estimate is overly conservative. features." As described in the Unsuccessful planned shutdowns summary notebook, "The would be captured in the review of manual shutdowns are included plant events, reviewed for impact and in the analysis because of their included in the initiating events frequency and because they modeled.

represent changes in operating The ASME Standard interpretations #5 state which result in the demand and #6 indicate that the Manual on available equipment to reach Shutdown initiator is not included in a safe shutdown condition. The the PRA, but should be included in manual shutdowns are transition risk or low power risk controlled evolutions that have models. Interpretation 5 states; different characteristics than a "Question: Is it a requirement to SCRAM challenge. The manual include "non-forced" manual trips shutdowns generally represent a which are part of the normal shutdown reduced challenge relative to procedure when counting initiating that of a turbine trip; however, events.

also possible is a manual Reply: No, a normal controlled shutdown resulting from shutdown would not present the same equipment unavailability where challenges as a trip from full power.

accident mitigation capability This event is more appropriate for a has been reduced prior to the transition model and outside of the demand for the shutdown."

scope of the standard".

Therefore, the peer review This position is repeated in suggestion is noted, but no Interpretation 6; "Question: Is it a changes were made to delete requirement to include "forced" (e.g.,

manual shutdowns from the technical specification 3.03 actions) or initiating events given any "non-forced" (e.g., manual shutdowns shutdown can on some level for refueling) when the resulting challenge normal plant shutdown follows normal plant operation.

procedures with no off-normal conditions requiring a reactor scram?

Reply: No, the risk needs to be captured in a transition risk or low power risk model, which is outside the scope of RA-Sb-2005.

TABLE2 to PLA-7193 Page 28 of 60 SUPPORTING REQUIREMENTS MEETING CAPABILITY CATEGORY II OR GREATER WITH ASSOCIATED FACTS AND OBSERVATIONS SUPPORTING F&O #,DESCRIPTION OF RESOLUTION IMPACT REQUIREMENT GAP, AND SIGNIFICANCE IE-A2 1-16: The loss of control room Per discussion with the peer Documentation (Met Cat IIIIIIII) ventilation is not considered to be review evaluator, the item. The gap an initiator in the model. The identified condition can be has been closed initiating events notebook states resolved with additional for the JUL12R1 that this initiator was dismissed, but documentation. Information model.

there is no detailed discussion why regarding the Appendix R this was done. Upon discussion fire calculation and loss of with Susquehanna personnel, it was control room ventilation was determined that there is a basis for added to the Initiating Events dismissing this initiator, but it was Notebook, Section 2.4.2, to not documented.

support that no new initiator is needed.

This is a suggestion because it is a documentation concern only.

IE-A9 6-28: The process by which LER Per discussion with the peer Documentation (Met Cat II) reports are searched to identify review evaluator, it was item. The gap precursors needs to be documented. desired to have additional has been closed documentation outlining the for the JUL12R1 This is a suggestion because it LER review. Section 2.3.8 model.

involves documentation only.

of the Initiating Events Notebook was expanded to provide more detail to the LER review process and whether or not the events described needed to be included in the PRA.

IE-C3 4-3: Use ofNUREG-0666 includes The Initiating Events None, gap has (Met Cat 11111111) a generic recovery estimate. No Notebook Section 3.5.2 was been closed for indication of Susquehanna revised to remove credit for the JUL12R1 Related SRs adjustment. Section 3.5.2 of the IE DC bus repair recovery.

model.

IE-C11 Notebook uses the credit for Accordingly, the initiating (Met Cat IIII/III) recovery for loss of DC bus events event frequency was also from NUREG-0666.

changed in Table 4-1 and in the JUL12R1 model.

This is a finding. Use ofNUREG-0666 is a very old reference and a more contemporary reference (NUREG-6928) should be used.

TABLE2 to PLA-7193 Page 29 of 60 SUPPORTING REQUIREMENTS MEETING CAPABILITY CATEGORY II OR GREATER WITH ASSOCIATED FACTS AND OBSERVATIONS SUPPORTING F &0 #, DESCRIPTION OF RESOLUTION IMPACT REQUIREMENT GAP, AND SIGNIFICANCE IE-C6 6-21: No potential Initiating Events The proposed resolution None, gap has (Met Cat 11111111) appear to be screened based on from the peer reviewer been closed for criteria (a) or (b).

evaluator was to estimate the the JUL12R1 frequencies for loss of the model.

A loss of River Water intake and river water intake and loss of Loss of the Spray Pond (UHS) are the 13.8 kV bus to confirm screened on the basis that it would that they are appropriately not result in an immediate plant screened out under the shutdown. However, this credits guidance of SR IE-C6. The operator actions to remove any screening determined that debris blocking the intake structure, these system losses should be and states that failure of this action added to the risk model. The would result in an initiating event river water makeup similar to a loss of condenser heat discussion inthe Initiating sink. Per discussions with PRA Events Notebook, section staff, debris/fouling/ice are unlikely 2.4.5 was revised.

The (no recorded plant events), and river water makeup system is there appear to be no common now an input to the service suction lines that would impact water initiating event fault multiple systems.

tree. CCF screen and pump terms were also added to the A loss of a 13.8 kV bus was model loss of service water screened on the basis that it would support system initiating appear like a loss of feed water with event fault tree and are some impacts on service documented in the water/instrument air. The notebook Component Data Notebook.

then states that this IE is screened Also added loss of 13.8 kV as it is assumed to be adequately buses as special initiators to included in as a turbine trip the initiating event notebook.

transient initiator with subsequent failure of a 13.8 kV AC bus. An estimation of this IE frequency should be made to verify it conforms with the Screening Criteria given in this SR.

This is a suggestion as the frequencies of the screened IEs are likely low enough to support their being screened.

TABLE2 to PLA-7193 Page 30 of 60 SUPPORTING REQUIREMENTS MEETING CAPABILITY CATEGORY II OR GREATER WITH ASSOCIATED FACTS AND OBSERVATIONS SUPPORTING F&O #,DESCRIPTION OF RESOLUTION IMPACT REQUIREMENT GAP, AND SIGNIFICANCE IE-C8 4-1: Section 3.5 ofthe IE Notebook The peer review finding None, gap has (Met Cat IIIIIIII) provides the fault tree method and noted that the special been closed for results of the support system initiating events fault trees the JUL12Rl Related SRs initiating events. The initiating described in the initiating model.

IE-Dl event fault trees were developed events notebook were not (Met Cat I/IIIIII) from the mitigation fault tree. Only located in the referenced the Service Water tree is found in individual system notebooks.

the system notebook. The support The peer review finding system dependencies were removed specifically questions the from the mitigation tree to develop documentation of the special the initiating event fault tree. The initiating events fault trees support system initiating event fault since the frequency is trees developed for loss of off-site calculated within the model.

power, loss of CIG, loss of SW, The special initiating event loss of IA, loss of TBCCW, and fault trees have been added loss of RBCCW are found in the directly to the Initiating Susquehanna CAFTA fault tree Events Notebook in under gates identified for each Appendix F.

system. The cutset results are shown in Appendix F of the IE Notebook for each system IE.

This is a finding because Appendix F states that the System IE fault trees are located in the respective system notebooks, however, this was not found to be the case for RBCCW, TBCCW, IA and CIG.

IE-C14 6-25: Appendix H of the Initiating Per the referenced possible None, gap has (Met Cat 1/II)

Events notebook addresses the resolution, Appendix H of been closed for ISLOCA frequency calculation and the Initiating Events the JUL12Rl appears to address most of the Notebook was updated to model.

items required by this SR.

address the identified gap. A However, no discussion of discussion of surveillances interlocks of relevant surveillance and interlocks has been tests and procedures was found.

added to Appendix H for ISLOCAs.

This is a finding. Consideration of protective interlocks and plant surveillance procedures is required by this SR.

TABLE2 to PLA-7193 Page 31 of 60 SUPPORTING REQUIREMENTS MEETING CAPABILITY CATEGORY II OR GREATER WITH ASSOCIATED FACTS AND OBSERVATIONS SUPPORTING F&O #,DESCRIPTION OF RESOLUTION IMPACT REQUIREMENT GAP, AND SIGNIFICANCE IE-D3 6-26: Assumptions are discussed Open item Documentation (Met Cat IIIIIIll) throughout the IE notebook.

item. No impact.

Sources of Uncertainty regarding initiating events are included in the discussion in Section D.1.4 of the Summary Notebook.

A single section/list of all assumptions made was not found, such a list may be beneficial.

This is a suggestion as all assumptions made appear to be captured throughout the documentation.

AS-A9 2-1: Section 2.1.16 of Event Tree I Reference to MAAP None, gap has (Met Cat III)

Success Criteria Notebook, limitations have been been closed for Thermal-Hydraulic Code incorporated in the Event the JUL12R1 Limitations, states that MAAP4 Tree I Success Criteria model.

does not calculate peak fuel Notebook.

temperature well. However, fuel temperature calculated in MAAP is used to define core damage.

Analysis and justification for the use of MAAP4 to define core damage is provided in Section 2.1.1 of the, Performance Requirements for Maintaining Core, Vessel, and Containment Integrity During Severe Accidents notebook.

Section 2.1.1 ofthe performance requirements notebook should be referenced in the Event Tree I Success Criteria Notebook to avoid confusion on the use of MAAP4 with the limitation described.

This is a suggestion to clarify documentation in the Event Tree I Success Criteria Notebook.

TABLE2 to PLA-7193 Page 32 of60 SUPPORTING REQIDREMENTS MEETING CAPABILITY CATEGORY II OR GREATER WITH ASSOCIATED FACTS AND OBSERVATIONS SUPPORTING F&O #,DESCRIPTION OF RESOLUTION IMPACT REQUIREMENT GAP, AND SIGNIFICANCE AS-B3 1-20: There is no separate success Open item Documentation (Met Cat 1/IIIIII) criteria notebook in the item. No impact Susquehanna documentation.

Rather, the plant uses the event tree notebook for both AS and SC technical elements. This results in some of the success criteria information being scattered through the event tree sequence descriptions.

This is a suggestion, since it is a potential documentation enhancement.

AS-BS 1-21: Expanded documentation of Open item Documentation (Met Cat 1/111111) the FFT model top logic would item. No impact facilitate greater understanding of the model by PRA engineers new to the group and would further enhance the scrutinizing of the model.

This is a suggestion since it involves model documentation only.

TABLE2 to PLA-7193 Page 33 of 60 SUPPORTING REQIDREMENTS MEETING CAPABILITY CATEGORY II OR GREATER WITH ASSOCIATED FACTS AND OBSERVATIONS SUPPORTING F&O #,DESCRIPTION OF RESOLUTION IMPACT REQUIREMENT GAP, AND SIGNIFICANCE AS-Cl 1-13: The accident sequence model Open item Documentation (Met Cat 1111/III) is constructed using a very large item. No impact number of transfers. This made the Related SRs model difficult to review. It is also AS-All constructed in a manner such that (Met Cat IJIIIIII) the CDF tree and the Level 2 tree are integrated. While there is no evidence from the peer assessment that was performed that the model fails to accurately model the as-built, as-operated plant (the quantification results are reasonable given the operation and design of the plant). However, the event tree structure does not lend itself readily to evaluation. This should not hamper the ability to pursue PRA applications. However, as more hazards are added to the spectrum of the PRA (internal fire, seismic, etc.) the event tree structure may become difficult to deal with.

This is a suggestion because it primarily addresses potential issues that may arise in the future.

AS-Cl 1-46: Consider the creation of a Open item No impact. The (Met Cat IIIIIIII) separate LOOP tree. This would F&O suggests a allow for increased model different method readability and would diminish the to model the need for the use of recoveries.

Loss Of Off-Site Power.

This is a suggestion, since the as-built, as-operated plant is effectively represented by the current model.

TABLE2 to PLA-7193 Page 34 of60 SUPPORTING REQUIREMENTS MEETING CAPABILITY CATEGORY II OR GREATER WITH ASSOCIATED FACTS AND OBSERVATIONS SUPPORTING F &0 #, DESCRIPTION OF RESOLUTION IMPACT REQUIREMENT GAP, AND SIGNIFICANCE SC-A3 3-2: Section 2.6.2 of the Event Open item Documentation (Met Cat 1/IIIIII)

Tree/Success Criteria Notebook item. No impact describes the core protective Related SRs functions identified in the AS and SC-C1 SC Notebook. Table 3.3.1 through (Met Cat l/WIII) 3.3.11 (LOCA) and Table 3.4.1 AS-A2 through 3.4.10 {TRANSIENT)

(Met Cat l/WIII) provide the functional level SC for the key critical safety functions for each initiator category. Attachment M provides key results of MAAP runs to support the SC.

However, no similar Tables as LOCA and TRANSIENT key safety functions were found that described the key safety functions for A TWS and ISLOCA.

This is a document suggestion.

TABLE2 to PLA-7193 Page 35 of 60 SUPPORTING REQIDREMENTS MEETING CAPABILITY CATEGORY II OR GREATER WITH ASSOCIATED FACTS AND OBSERVATIONS SUPPORTING F&O #,DESCRIPTION OF RESOLUTION IMPACT REQUIREMENT GAP, AND SIGNIFICANCE SC-A6 3-3: The success criteria given are System flow used for Negligible, the (Met Cat IIIJJIII) consistent with the features MAAP analysis is current analyses described in the system notebook conservative (i.e. lower) are conservative.

document. The MAAP input deck relative to predicted post-However, using and runs use flows, pressures, and modification system flow.

a higher fire other parameters that are consistent Therefore, the current credit water pump flow with the values described in the for fire water makeup based has the potential station system description on the MAAP analyses are to yield success documents and in the PSA system conservative. No modeling for re-flooding notebooks. The success criteria are changes are made at this the core after also tied to plant's procedures.

time, but this should be depressurization.

considered in a future PRA If this is However, there is a plant model update.

successful, the modification on the Fire Water fire pump, System to replace a 50 foot 3 inch injection flow hose with 200 foot of 5 inch hose.

path and System flow is potentially operator action increased, and SC might need to be for the fire water updated to reflect the plant as-build injection condition. This may improve the alignment would plant over SC as well.

become more important.

This a finding since the unanalyzed modification may impact overall model success criteria and implemented logic.

SC-B4 2-2: Event Tree I Success Criteria Documentation issue.

None, gap has (Met Cat IIIJJIII)

Notebook Section 2.1.6 describes Reference to been closed for Thermal-Hydraulic Code BWRSAR/MAAP the JUL12Rl Related SRs Limitations.

comparison was added to the model.

AS-A9 Event Tree/Success Criteria (Met Cat III)

There is no discussion of the Notebook section 2.1.6.

MAAP4 limitation concerning its use in analysis of large break LOCAs.

This is a suggestion since the large LOCA MAAP calculations were compared to existing BWRSAR calculations and found acceptable for use in the PRA.

TABLE2 to PLA-7193 Page 36 of60 SUPPORTING REQIDREMENTS MEETING CAPABILITY CATEGORY II OR GREATER WITH ASSOCIATED FACTS AND OBSERVATIONS SUPPORTING F&O #,DESCRIPTION OF RESOLUTION IMPACT REQUIREMENT GAP, AND SIGNIFICANCE SY-A3 5-4: PRA model system functions Open item Documentation (Met Cat Illlllll) documented in Section 1.2 of the item. No impact.

system notebooks are based on Maintenance Rule functions. Did not find a reference for the source of these functions (e.g.,

Maintenance Rule basis document) identified in the system notebooks.

This is a suggestion because it pertains primarily to documentation.

SY-AlO 5-3: The effect of variable success Open item Documentation (Met Cat 1/IIIIII) criteria was not clearly documented item. No impact.

for three system notebooks RCIC),

Related SRs CRD and CST and RWST.

HR-F2 (Met Cat III)

For example, success of RWST is SY-A2 defined simply as to provide (Met Cat 1/II/III) manual makeup to the Unit 1 CST SY-C2 and the Unit 2 CST. Timing (Met Cat 1/II/III) information is found in the event tree notebook for different scenarios. The evaluation of 037-N-N-RWST-0 in the HRA notebook indicates a different timing than found in the event tree notebook.

It is not clear from the CRD system notebook what CRD flow is credited and the basis in success criteria. It would be clearer if this and other success criteria are documented in a separate notebook to tabulate various combinations of criteria applicable to accident scenarios.

This is a suggestion because it applies to documentation only.

TABLE2 to PLA-7193 Page 37 of 60 SUPPORTING REQUIREMENTS MEETING CAPABILITY CATEGORY II OR GREATER WITH ASSOCIATED FACTS AND OBSERVATIONS SUPPORTING F&O #,DESCRIPTION OF RESOLUTION IMPACT REQUIREMENT GAP, AND SIGNIFICANCE SY-A13 6-31: Assumption 2 of Section 2.2 Open item Documentation (Met Cat 11111111)

(general assumptions) in the item. No impact.

System Notebook Template discusses screening potential flow diversion paths if the diameter of the pathway is less than 1/3rd the diameter ofthe primary pathway.

This assumption may not necessarily be true and requires more justification on a system-by-system basis. Per discussion with PRA staff, the general assumption on l/3rd pipe diameter is not actually used. Flow diversion are analyzed on a system by system basis, and are documented in Section 2.1.3 of each notebook discusses the identified flow paths.

This is a suggestion to remove the unused assumption from the notebook.

SY-A15 6-32: Per the system notebook Open item Documentation (Met Cat I/II/111) template, several item. No impact.

components/failure modes have been screened (plugging of components, leakage/rupture of a components, etc.). This appears to be in accordance with the requirements of this SR. However, some additional discussion to verify appropriate screening should be added to the documentation.

This is a finding since quantitative criteria were not cited.

TABLE2 to PLA-7193 Page 38 of 60 SUPPORTING REQUIREMENTS MEETING CAPABILITY CATEGORY II OR GREATER WITH ASSOCIATED FACTS AND OBSERVATIONS SUPPORTING F&O#, DESCRIPTION OF RESOLUTION IMPACT REQUIREMENT GAP, AND SIGNIFICANCE SY-A16 6-33: Discussion ofthese events Open item Documentation (Met Cat IIII) was not found in the system item. No impact.

notebooks and were expected to be found in Section 2.3.2 (example, discussion of pre-initiator events such as 054-I-AC-PMP-H was not found in the ESW notebook, outside the "copy-paste" of the fault tree and cutsets).

This is a suggestion as the pre-initiator events are included in the model and the HRA documentation but are not described in the system notebooks.

SY-A21 1-25: The RHR System Notebook Open item Documentation (Met Cat IfiiJill) contains a reference point estimate item. No impact.

probability for the RHR water hammer event that is postulated in NED0-33150-NP (BE 149-II-N-H20_PART). An expanded discussion of this phenomenology should be presented and details of its injection accident sequence model should be presented.

This is a suggestion since it is a documentation enhancement.

TABLE2 to PLA-7193 Page 39 of 60 SUPPORTING REQUIREMENTS MEETING CAPABILITY CATEGORY II OR GREATER WITH ASSOCIATED FACTS AND OBSERVATIONS SUPPORTING F&O #,DESCRIPTION OF RESOLUTION IMPACT REQUIREMENT GAP, AND SIGNIFICANCE SY-B3 1-17: Check valve CCF is slightly Upon review, it was None, gap has (Met Cat IIIIIIII) more than 2 orders of magnitude determined that check valve been closed for lower in CCF probability than CCF basic event terms for the JUL12R1 MOV failures, but less than 2 the HPCIIRCIC Feedwater model.

orders below pump failure to start (FW) injection paths and and failure to run CCF terms.

ESW paths should be Therefore, it is not appropriate to included in the risk model.

screen check valve CCF unless The basic events and CCF there are MOVs (or other high CCF data is as documented in the failures) in the system.

component data notebook.

Of particular concern are check valves which are within injection pathways to the reactor shared by multiple systems (such as one injection line through with HPCI and FW inject and the opposite injection line inject RCIC and FW) in which the shared lines only have check valves. CCF modeling of such check valves is important to incorporate.

This is a finding because there is a potentially significant common cause failure that was not added to the model.

TABLE2 to PLA-7193 Page 40 of 60 SUPPORTING REQUIREMENTS MEETING CAPABILITY CATEGORY II OR GREATER WITH ASSOCIATED FACTS AND OBSERVATIONS SUPPORTING F&O#, DESCRIPTION OF RESOLUTION IMPACT REQUIREMENT GAP, AND SIGNIFICANCE SY-B3 6-34: Selection of CCF groups is Section 4.3.24 of Component None, gap has (Met Cat 11111111) discussed in Data Notebook Section Data Notebook evaluates the been closed for 3.0. CCF groups follow guidance in CCF for check valves in the the JUL12Rl NUREG/CR-5485 and are based on RHR, CS and RHRSW model.

similarities in service conditions, systems. The conclusion is environment, design or the CCF of check valves in manufacturer, maintenance. CCF these systems is not required groups included pumps, MOV s, air since their CCF is more two compressors, etc.

orders of magnitude lower than the highest failure However, per discussion in Section probability of the other 3 of Data Notebook, some components in the same component types, such as filters, system train that results in check valves, and circuit breakers, the same effect on system were screened due to low operation.

probability. This may not necessarily be true. For example, Strainer (filter) plugging for based on Table 4-1 the probability the RHR and Core Spray for 2 of 4 RHR pumps failing to Pumps is modeled.

start is 8.4E-7. With a probability of a check valve failing to open of The CCF of circuit breakers lE-5 and assuming a Beta factor of for motor driven equipment 8.5E-3, a probability of 2 of 4 is not modeled since the pump discharge check valves failure of the circuit breaker failing to open would be ~ lE-7, for motor driven equipment which is less than 2 orders of is included in the failure rate magnitude lower than the pump of the driven equipment failure to start CCF term. In (NUREG/CR-6928).

addition, plugging of strainers/HXs/etc. can have CCF probabilities that are within an order of magnitude or two less than their independent probabilities.

This is a finding as some CCF terms may have been inappropriately screened from the model.

Possible Resolution Demonstrate that screened CCF terms were appropriately screened, or incorporate them into the model.

TABLE2 to PLA-7193 Page 41 of 60 SUPPORTING REQUIREMENTS MEETING CAPABILITY CATEGORY II OR GREATER WITH ASSOCIATED FACTS AND OBSERVATIONS SUPPORTING F&O #,DESCRIPTION OF RESOLUTION IMPACT REQillREMENT GAP, AND SIGNIFICANCE SY-B15 5-6: Section 2.3.2 in each of the Open item Documentation (Met Cat IIIIIIII) system notebooks discusses human item. No impact.

interactions and lists HRA basic events. Also refer to the HRA notebook. An example of operator interface dependencies across systems is 037-N-N-XTIE-0, OPERATOR FAILS TO XTIE RWST TO CST, which provide CST makeup from the RWST. This HRA basic event is among the events listed in Section 2.3.2 of the RCIC system notebook, but was not included in Section 2.3.2 of the HPCI and Core Spray system notebooks.

Documentation of operator interface dependencies across systems in the systems notebooks is not complete.

This is a suggestion because it only pertains to documentation.

TABLE2 to PLA-7193 Page 42 of 60 SUPPORTING REQUIREMENTS MEETING CAPABILITY CATEGORY II OR GREATER WITH ASSOCIATED FACTS AND OBSERVATIONS SUPPORTING F&O #,DESCRIPTION OF RESOLUTION IMPACT REQUIREMENT GAP, AND SIGNIFICANCE HR-A3 5-2: Statement in Section 4.1.2.1 on This item was determined to None, gap has (Met Cat IIIIIIII) page 60: Due to staggered be a documentation and been closed for testing/maintenance practices, like terminology issue and the the JUL12Rl components in different divisions manner that SR HR-A3 model.

are generally not susceptible to redundant systems was restoration errors and "common treated in the HRA notebook, mode" errors are screened.

specifically the systems review in section This is a finding. Need basis for not 4.1.2.1.After further review identifying the work practices of SR HR-A3, it was identified above (HR-Al, HR-A2) determined that only single that involve a mechanism that activities that simultaneously simultaneously affects equipment disable redundant trains or in either different trains of a diverse systems require the redundant system or diverse development of common systems [e.g., use of common mode failure events, as calibration equipment by the same exemplified in SR HR-A3.

crew on the same shift, a Maintenance acts that are maintenance or test activity that directed by separate requires realignment of an entire procedures on different system (e.g., SLCS)].

divisions or systems, even if they are performed in an outage, are NOT required to be identified as common mode failure events. The identification process used in the SSES pre-initiator HRA is consistent with SR HR-A3.

The documentation was updated to provide clarification.

TABLE2 to PLA-7193 Page 43 of 60 SUPPORTING REQUIREMENTS MEETING CAPABILITY CATEGORY II OR GREATER WITH ASSOCIATED FACTS AND OBSERVATIONS SUPPORTING F&O #, DESCRIPTION OF RESOLUTION IMPACT REQUIREMENT GAP, AND SIGNIFICANCE HR-Bl 7-2: Although some screening criteria The HRA notebook, Section None, gap has (Met Cat Illlll) are identified in selected sentences 4.1.2.1, has been updated to been closed for the throughout the document, a succinct include a specific set of JUL12R1 model.

section outlining screening criteria is screening criteria. The text has not reiterated in the HRA Notebook.

been updated to clarify what the Although Section 4.1.2.1 ofthe HRA test needs to do in order for it to Notebook, largely identifies be credited (identify the error).

components that are to be included in The description of the potential the analysis, this section does not recovery mechanisms has also succinctly identify the criteria under been enhanced to clarify that which components and actions can be mechanisms described in screened from the analysis. Note that it section 4.1.2.5 are the same as is stated in section 4.1.2.1 that those listed for each procedure "Miscalibrations that impact a single review section.

component may be screened from further consideration and assumed to be inherent in the component failure rate." Screening calibration activities on that basis is not a screening criteria of ASEP as identified in this associated supporting requirement: SR-B 1.

Therefore since unique screening criteria have been used in the Susquehanna HRA analysis that is not part of the ASEP process, a succinct and comprehensive listing of all pre-initiator screening criteria is required.

Later, Section 4.1.2.5 refers to the procedures used for the pre-initiator analysis of HFEs identified as 'risk-significant', which are listed in Attachment C. It is not noted however, if these procedures provide the post maintenance functional tests that would reveal misalignment It is noted that Attachment F of the HRA notebook defines some screening criteria for pre-initiator identification which presents screening of plant experience related to potential restoration errors or miscalibration errors to identify additional pre-initiator actions worthy of inclusion in the model.

This is a finding because a complete set of screening criteria for Type A events was not found in the documentation.

TABLE2 to PLA-7193 Page 44 of 60 SUPPORTING REQUIREMENTS MEETING CAPABILITY CATEGORY II OR GREATER WITH ASSOCIATED FACTS AND OBSERVATIONS SUPPORTING F&O #,DESCRIPTION OF RESOLUTION IMPACT REQUIREMENT GAP, AND SIGNIFICANCE HR-C2 7-5: Restoration errors screened on SR HR-C2 is attempting to None, gap has (Met Cat II/III) the basis of an administrative work ensure that specific failure been closed for practice procedure which may not modes are addressed for the the JUL12Rl be applicable during all stages of unscreened activities. SSES model.

low power and shutdown modes.

does not have unscreened common mode misalignment This is a finding because it is events. In addition, based on possible to have restoration errors the clarification and further during low power and shutdown review of SR HR-A3, the modes that affect equipment across HR-A3 requirement system trains.

identifies that only single activities that simultaneously disable redundant trains or diverse systems require the development of events.

Separate procedures I maintenance acts on different divisions or systems (even if they are performed in an outage) are NOT required in the development of events.

Clarification was provided in the HRA notebook in Revision 5.

HR-D2 7-7: A detailed analysis has been Expanded and/or corrected None, gap has (Met Cat II) performed for the HFEs that had a discussion was provided in been closed for risk achievement worth (RAW) the HRA notebook, sections the JUL12Rl Related SRs greater than or equal to 2.0 or a risk 4.2.3 and 4.2.1.4.

model.

HR-Gl reduction worth (RRW) greater (Met Cat II) than or equal to 1.005.

QU-F6 Consideration should be given to (Met Cat IIIIIIII) using the FV directly per the ASME Standard wording rather than indirectly through RRW.

This is a suggestion because it pertains to more direct correlation with the standard. Use the ASME Standard and RG 1.200 parameter ofaFV 0.005 rather than the RRW to avoid confusion.

TABLE2 to PLA-7193 Page 45 of 60 SUPPORTING REQUIREMENTS MEETING CAPABILITY CATEGORY II OR GREATER WITH ASSOCIATED FACTS AND OBSERVATIONS SUPPORTING F&O #,DESCRIPTION OF RESOLUTION IMPACT REQUIREMENT GAP, AND SIGNIFICANCE HR-D2 5-1: The screening criteria and Scoping values of 0.01 for None, gap has (Met Cat II) values used need to be more clearly independent pre-initiator been closed for defined within the Susquehanna events and 0.001 for the JUL12R1 HRA as also noted in SR HR-B2.

common cause pre-initiators model.

The nominal ASEP methodology are judged as reasonable has been used in the Susquehanna scoping estimates as HRA as the detailed methodology.

described in Section 4.1.2.4 of the HRA Notebook..

This is a suggestion, since there is The 1E-2 value that SSES no direct evidence that important employed is per the NRC's contributors have been missed.

guidance in NUREG-1792 document.

HR-E4 1-1: Simulator observations should Open item Negligible, F&O (Met Cat II/III) be conducted to further confirm the is a suggestion validity of assumptions in modeled that would operator actions.

enhance the HRA analysis.

This is a suggestion, since there is no requirement for such observations if a 'talk-through' was performed.

HR-F2 1-19: RHRSW is credited for 013-N-N-RHRSWX_L-0 None, gap has (Met Cat III) external injection past containment was added to the model as a been closed for venting. It was noted that the late RHRSW crosstie action the JUL12R1 Related SRs injection path must lined up to maintain alternate model.

AS-B3 (MOVs opened) before venting by injection after PC venting.

(Met Cat I/Il!ID) procedure. However, there is no The venting procedure steps step in the execution or cognitive to open the RHRSW crosstie portion of the HEP 013-N-N-valves prior to venting are RHRSWXTIE included in the execution error. The execution error This is a finding, since it may affect for both 013-N-N-the value for the HEP and the RHRSWXTIE and 013-N-N-quantification.

RHRSWX_L-0 reflects RHRSW alignment as alternate RPV injection.

TABLE2 to PLA-7193 Page 46 of 60 SUPPORTING REQUIREMENTS MEETING CAPABILITY CATEGORY II OR GREATER WITH ASSOCIATED FACTS AND OBSERVATIONS SUPPORTING F&O #, DESCRIPTION OF RESOLUTION IMPACT REQUIREMENT GAP, AND SIGNIFICANCE HR-Gl 1-10: Basic Event 054-01222AB-Open item.

Negligible, F&O (Met Cat II) 24AB 1-0 uses a screening HEP is a suggestion value. While this is by definition that would not a risk significant function by enhance the RAW or FV, the action does appear HRA analysis.

in some cutsets above 1E-9.

This is a suggestion, since screening values are allowed by the standard for non-significant events for Cat II.

HR-G2 7-8: The combination sum The Peer Review suggestion None, gap has (Met Cat IIIIIIII) technique presented in the HRAC questions the combination been closed for has no theoretical basis. Although sum technique used in the the JUL12R1 all of the HFE methodologies have EPRI HRA calculator and model.

limitations, it is more defensible to recommends consideration of choose an industry reviewed another approach. It was methodology that most closely determined acceptable to models the scenario according to retain the combined method the known limitations of the for actions with limited time methodology rather than adding the available for recovery cognitive errors of two unlike because the combined methodologies to compensate for method provides both the timing uncertainties.

detailed assessment of the CBDTM PSFs and accounts This is a suggestion. While the for the expected increase in HRA Calculator allows this Pc if the time available for approach, its basis may be subject recovery is limited. The to challenge.

method is retained because it allows detailed PSF (Performance Shaping Factors) assessment and accounts for the expected increase in cognitive error associated with limited time available for recovery and is allowed within the use of the HRAC

TABLE2 to PLA-7193 Page 47 of 60 SUPPORTING REQUIREMENTS MEETING CAPABILITY CATEGORY II OR GREATER WITH ASSOCIATED FACTS AND OBSERVATIONS SUPPORTING F &0 #, DESCRIPTION OF RESOLUTION IMPACT REQUIREMENT GAP, AND SIGNIFICANCE HR-G4 1-8: The description for event 013-The title of 013-N-N-None, gap has (Met Catll)

N-N-RHRSWXTIE-0 is RHRSWXTIE-0 was been closed for OPERATOR FAILS TO TIE IN corrected in the HRAC the JUL12R1 FIRE MAIN OR RHRSW WITHIN database and in the HRA model.

29 MINUTES. The mission time Notebook.

for this event, however, is 100 minutes.

This is a suggestion because the timing analysis for the event is correct.

HR-GS 1-4: There are several instances in The basis for manipulation None, gap has (Met Catll) the HRA Notebook where the times was carried forward in been closed for previous HRA analysis (Notebook) the HRA Notebook.

the JUL12R1 is quoted as a reference for the model.

manipulation time. The basis for these manipulation times should be carried forward to the new documentation.

This is a suggestion, since there is a basis for the manipulation time and this issue pertains only to documentation.

HR-GS 1-5: There is no documented basis The manipulation time for None, gap has (Met Catll) for the manipulation time for 013-013-N-N-RHRSWXTIE-0 been closed for N-N-RHRSWXTIE-0. Note that was obtained via PPL the JUL12R1 the utility staff subsequently noted operator interviews and model.

an accurate basis for the timing.

reference was. added to the HRA Notebook.

This is a suggestion, since the utility stated a basis for the manipulation time.

TABLE2 to PLA-7193 Page 48 of 60 SUPPORTING REQUIREMENTS MEETING CAPABILITY CATEGORY II OR GREATER WITH ASSOCIATED FACTS AND OBSERVATIONS SUPPORTING F&O#, DESCRIPTION OF RESOLUTION IMPACT REQUIREMENT GAP, AND SIGNIFICANCE HR-G7 1-7: Dependent HEPs MAN-The HRA dependency analysis None, gap has (Met Cat IIIIIIII)

OP _SPC_INJ_L-0 and 159-CNTVNT-has been completely re-been closed for the 0 are found in a dependent HEP Group performed with the JUL12Rl JUL12R1 model.

Related SRs with three elements. However, they are model. Additionally, F&O 1-7 QU-Cl not in a dependent HEP Group by has 2 parts: the dependency (Met Cat JJIIIIII) themselves (two event combination).

analysis question with regard to This appears to be inconsistent.

the manual MOV operation with containment venting actions, Table 5.3-1 gives an explanation that and the timing differences in the there is zero dependency between the dependency analysis file (DAF) actions. However, it appears that the and the HRAC. The second part timing information for 159-CNTVNT-of the explanation addresses the 0 in that table does not match that in need for the timing differences the HRA Calculator Database. If the between the DAF and the timing in the HRA calculator database HRAC in order to force the for that event is used, it would appear actions into their expected that there is, in fact, some level of chronological order. The first dependency between these events. This issue starts with MAN-combination is important to the OP _SPC_INJ_L-0 which was mitigation of long term DHR related broken into 2 actions: MAN-sequences.

OP _SPC_L-0 and MAN-OP _INJ_L-0. The revised HRA This is a finding because it has dependency analysis includes a quantitative impact.

dependent HEP for the new SPC action and both versions of containment venting. The 159-CNTVNT-0 action is in Combination 52. Combination 51 has MAN-OP _SPC_L-0 and 159-CNTVNTLOCAL-0.

Additionally, since MAN-OP _SPC_INJ_E-0 is not credited due to the timing constraints (i.e., HEP value=

1.0 and it is set to TRUE prior to quantification), there are no dependent HEPs which involve this early action.

TABLE2 to PLA-7193 Page 49 of60 SUPPORTING REQIDREMENTS MEETING CAPABILITY CATEGORY II OR GREATER WITH ASSOCIATED FACTS AND OBSERVATIONS SUPPORTING F&O #,DESCRIPTION OF RESOLUTION IMPACT REQUIREMENT GAP, AND SIGNIFICANCE HR-G7 1-9: The HEP values that are part The processing of the REPs None, gap has (Met Cat 11111111) of a dependent group are has been revised. A been closed for sometimes assigned and REP in the JUL12R1 model flag file has the JUL12R1 RR file that is arbitrarily high.

been created to elevate the model.

After performing the quantification, REPs prior to quantification, a post processing recovery is and the real values are applied to these non-dependent maintained in the REPs to return them to their "true" JUL12Rl.RR file.

value. Although the true REP value is seen in the HEP description, it is somewhat confusing to someone not familiar with the model; it can also cause issues when using the RR file to perform query operations for data extraction from the model.

This is a suggestion because it does not affect quantification.

HR-H2 1-48: A spot check of several HFEs Open item Negligible, this (Met Cat IIIIIIII) within the Susquehanna 2011 HRA F&Ois Update in V 411 used with the quantitatively DAF. HRA file reveals that insignificant.

individual operator actions are selectively credited where appropriate for recovery of potential execution errors. However the dependency values are often not used with the HRA calculator for the cognitive decision trees when a LD is assessed. While the use of "N/ A" produces realistic results in the case of ZD it provides unrealistic low values for cases where a higher dependency is suggested.

This is a suggestion, since it is not deemed to be quantitatively significant.

TABLE2 to PLA-7193 Page 50 of 60 SUPPORTING REQUIREMENTS MEETING CAPABILITY CATEGORY II OR GREATER WITH ASSOCIATED FACTS AND OBSERVATIONS SUPPORTING F&O #, DESCRIPTION OF RESOLUTION IMPACT REQUIREMENT GAP, AND SIGNIFICANCE HR-I2 7-12: The Susquehanna HRA Expanded and/or corrected None, gap has (Met Cat 1111/ITI)

Notebook, PA-B-NA-041, discussion was provided in been closed for documents the process used to the HRA notebook, sections the JUL12R1 characterize the HFEs used in the 4.2.3 and 4.2.1.4.

model.

model. It is noted however that some documentation is provided within the notebook which does not actually reflect the process used.

For example, assessing recovery factors based on time phasing appears not to have been done as is described in Table 4.2.1-11

[INCREMENTAL( 1)

CONDITIONAL FAILURE PROBABILITIES (NON-RECOVERY PROBABILITIES WITHIN EACH TIME PHASE)].

Rather, the recovery factors that are inherent within the HRA Calculator appear to be used in the actual modeling of the HFEs and such recovery factors do not account for time phasing.

This is a suggestion because it relates to updating the documentation within the HRA notebook to reflect only what is done in the system models.

DA-Al 4-6: There is no clear statement Documentation was added to None, gap has (Met Cat I!IIIIII) documenting that the system the Component Data been closed for analysis or the overall model was Notebook.

the JUL12Rl Related SRs used to determine which basic model.

DA-A4 events were identified that required (Met Cat I/IIIIII) development of data.

This is a finding since identification of the basic events from the system analysis is required by the ASME standard.

TABLE2 to PLA-7193 Page 51 of 60 SUPPORTING REQIDREMENTS MEETING CAPABILITY CATEGORY II OR GREATER WITH ASSOCIATED FACTS AND OBSERVATIONS SUPPORTING F&O #,DESCRIPTION OF RESOLUTION IMPACT REQUIREMENT GAP, AND SIGNIFICANCE DA-C4 4-8: The Component Data Added discussion for None, gap has (Met Cat Illl/III)

Notebook evaluates the evaluation of failures to been closed for unavailability in Appendix B using Section B.4 ofthe the JUL12Rl plant data taken from Maintenance Component Data Notebook model.

Rule and/or MSPI as shown in and added cross-reference to Table B-8. Table B-10 shows the categories to the PRA Maintenance Rule Functional comments field in Table B-Failure Data that was evaluated for 10. This revision is in line inclusion in the Bayes update.

with the proposed resolution However, there is no clear basis provided by the peer review documented in Section B.2 for how team and documents the events were screened to identify method used for analysis of failures to be included in the model data applicability.

for the data analysis.

This is a finding since the requirement is to provide a clear basis for identification of failures for inclusion in the data analysis.

DA-C14 1-22: Coincident maintenance A sensitivity case is now None, gap has (Met Cat I/IIIIII) unavailability is well accounted for discussed in the component been closed for in the Susquehanna PRA. However, data notebookSection B.3.3 the JUL12Rl Related SRs there is a maintenance combination which indicates that this model.

SY-A20 of risk significant equipment which additional combination is not (Met Cat l!II/lll) may occur that is not accounted for warranted due to very low in the PRA model that is allowed risk impact. Other by the 13 week schedule. That combinations were not combination is in Week for of the identified.

Table G-1 work matrix, which is the Blue Max portable diesel generator and the BID ESW HV AC system.

This is a suggestion, since the equipment is not considered to be redundant per strict interpretation of the ASME Standard requirement.

TABLE2 to PLA-7193 Page 52 of 60 SUPPORTING REQUIREMENTS MEETING CAPABILITY CATEGORY II OR GREATER WITH ASSOCIATED FACTS AND OBSERVATIONS SUPPORTING F&O #,DESCRIPTION OF RESOLUTION IMPACT REQUIREMENT GAP, AND SIGNIFICANCE DA-El 4-7: Sections in the Summary The Component Data None, gap has (Met Cat 1/IIIIII)

Notebook and in the Component Notebookwas revised to been closed for Data Notebook are identified as incorporate the title the JUL12R1 Related SRs "Appendices... " when in fact the Attachment instead of model.

AS-C1 notebooks identify the Appendix where appropriate.

(Met Cat I!II/III) corresponding sections as SY-C1 "Attachments."

(Met Cat I!IIIIII)

Table B-1 in the Component Data Notebook refers to sections of the notebook and to the Systems Notebooks as "Appendix... " when in fact they are identified as "Attachment...

II This is a suggestion since it involves documentation only. The roadmap designation of "Appendix... " led to confusion and difficulty in finding the correct section in the notebook.

QU-B7 1-4 7: There is a general discussion The JUL12R1 model None, gap has (Met Cat 1/IIIIII) regarding the rationale for the Quantification and Summary been closed for combinations in the mutually Notebook,, section A.2 and the JUL12R1 exclusive file. However, the Table A.2-1, provide the model.

rationale for each combination is mutually exclusive basic not explicitly discussed in the event combinations and the documentation. This is a basis for exclusion.

suggestion because it pertains to documentation only.

QU-B9 1-38: It was noted that there are Added 0.0 probability events None, gap has (Met Cat IIIIIIII) several negated events with a to flag file as false to be been closed for probability of 0.0 that appear in the assigned prior to the JUL12R1 CDF cutsets (specifically, events quantification.

model.

like -EFORB). These events, while useful for the cutset readability and debugging, should be set to false in a flag file for "production" quantifications.

This does not have a significant impact on the quantification (it only adds an insignificant conservatism) and therefore is a suggestion.

TABLE2 to PLA-7193 Page 53 of 60 SUPPORTING REQUIREMENTS MEETING CAPABILITY CATEGORY II OR GREATER WITH ASSOCIATED FACTS AND OBSERVATIONS SUPPORTING F&O #,DESCRIPTION OF RESOLUTION IMPACT REQUIREMENT GAP, AND SIGNIFICANCE QU-Dl 6-35: Only the top 10 cutsets are This peer review suggestion None, gap has (Met Cat 1/IIJIII) listed or described in any detail.

is directed to SR been closed for The percent contribution to total requirements QU-Dl and the JUL12Rl Related SRs CDF of these cutsets was not give, QU-D5. Requirement QU-model.

QU-D5 although the individual Dl requires reviewing a (Met Cat I/II/Ill) contributions are (the total appears sample of the significant to be -30% ofCDF).

accident sequences/cutset sufficient to determine that A listing of those cutsets selected the logic is correct. QU-D5 for in-depth review for the non-involves reviewing a sample significant cutset review process of non-significant accident would enhance the documentation. cutsets or sequences to determine they are This is a suggestion as the review reasonable and have physical of cutsets appears to be thorough, meaning. Instead of based on discussions with PRA selecting a random number staff.

of cutset to review, the top cutsets contributing > 1% to the overall CDFILERF were reviewed. This constitutes a review of significant cutsets.

A sampling of non-significant cutsets was selected for review of reasonableness and meaning.

These cutsets and their description were added to the summary notebook where in the past, only conclusion of reasonableness was provided.

TABLE2 to PLA-7193 Page 54 of 60 SUPPORTING REQUIREMENTS MEETING CAPABILITY CATEGORY II OR GREATER WITH ASSOCIATED FACTS AND OBSERVATIONS SUPPORTING F&O#, DESCRIPTION OF RESOLUTION IMPACT REQUIREMENT GAP, AND SIGNIFICANCE QU-D2 6-38: Section 3.4 of Attachment A The item identified requests None, gap has (Met Cat 1/IIIIII) of the Summary Notebook additional discussion and been closed for discusses dominant core damage justification to the statements the JUL12Rl sequences and provides a of reasonableness. The model.

description of why these sequences Quantification and Summary result in CDF/LERF.

Notebook was revised to include additional sequence However, further review and discussion and justification discussion of the results would help of reasonableness given plant verify model reasonableness.

operation. Additional Section 4 includes a review of basic discussion for LERF event importance, initiator differences found in section contributions to CDF/LERF, and 3.5 was also provided.

significant operator actions. The Section 4.1, important discussion is focused on what items systems, was also enhanced changed since the previous by providing a discussion of revision, rather than the the component basic event reasonableness of the results (i.e.,

importances. In general, why is LOOP -50% of CDF when where appropriate, additional the plant has a 5th diesel and the discussion was added to Blue Max diesel for charging results sections to better batteries?).

demonstrate statements of reasonableness.

This is a finding as further documented review and discussion of results is needed to verify the reasonableness of the model.

TABLE2 to PLA-7193 Page 55 of 60 SUPPORTING REQUIREMENTS MEETING CAPABILITY CATEGORY II OR GREATER WITH ASSOCIATED FACTS AND OBSERVATIONS SUPPORTING F&O #,DESCRIPTION OF RESOLUTION IMPACT REQUIREMENT GAP, AND SIGNIFICANCE QU-D6 6-3 7: Importance of Operator The dependent operator None, gap has (Met Cat Illlll) actions are given in terms of RAW action basic event been closed for and RRW. However, the nomenclature that was the JUL12Rl quantification process appears to provided in the JUL12 risk model.

remove dependent HEPs from the model was determined not cutsets and replace them with a complete. During the peer single basic event containing the review, the noted operator total dependent failure probability.

actions provided to the peer No discussion was found regarding review team were only how this might impact Importance independent actions. Upon Measures for REPs.

review of the basic events, it was determined that the This is a suggestion as it does not dependent operator action directly impact the model or nomenclature did not include quantification process, but can the -0 at the end of the basic distort model results if the effects event name. Therefore, upon are not accounted for.

data sorting, the complete list of operator actions was not initially provided to the peer review team. The dependent operator actions are identified by a beginning letter Z annotation and now end with a -0 annotation.

Therefore any future assessment and search for operator actions and their importance will be complete.

All operator actions both independent and dependent now end with -0.

TABLE2 to PLA-7193 Page 56 of 60 SUPPORTING REQUIREMENTS MEETING CAPABILITY CATEGORY II OR GREATER WITH ASSOCIATED FACTS AND OBSERVATIONS SUPPORTING F&O #,DESCRIPTION OF RESOLUTION IMPACT REQUIREMENT GAP, AND SIGNIFICANCE QU-D7 6-36: Importance measures for Section 4.1 of the None, gap has (Met Cat 1/IIIIII) basic events are given in Table 4.1-Quantification and Summary been closed for 1, and appears to be based on RRW Notebookprovides a review the JUL12R1

> 0.1. The Summary Notebook of component/system basic model.

indicates that these results were event importance. The reviewed and appear reasonable.

importance measures Importance measures for all basic reviewed in the notebook events are given in Attachment B were revised to include for CDF (both units), and Fussell-Vesely and Risk Attachment C for LERF (both Achievement Worth (RAW).

units).

The listed basic events are those having importance While Table 4.1-1 is titled measures FV greater than

'Important Components to 0.005 and RAW greater than Reduction in Risk (RRW),' this

2. A discussion supporting a appears to be a misnomer as the reasonable results conclusion items listed in the table are basic was provided. The results events. No component importance were determined to be measures were found in the acceptable when considering documentation.

plant configuration and the changes made to the PRA This is a finding as reviewing model during the latest data component importance is required update.

by this SR.

QU-E2 1-44: With the exception of the Open item Documentation (Met Cat I/IIIIII) system notebooks, assumptions item. No impact tend to be scattered throughout the documents. Consider consolidating all assumptions into a single section of each technical notebook.

This is a suggestion since it applies to documentation only.

TABLE2 to PLA-7193 Page 57 of 60 SUPPORTING REQIDREMENTS MEETING CAPABILITY CATEGORY II OR GREATER WITH ASSOCIATED FACTS AND OBSERVATIONS SUPPORTING F &0 #, DESCRIPTION OF RESOLUTION IMPACT REQUIREMENT GAP, AND SIGNIFICANCE QU-E3 1-26: There are several classes of Error Factors were added for None, gap has (MetCatiD) basic events which do not have all basic events or type codes been closed for associated error factors. These in the risk model reliability the JUL12Rl Related SRs include: internal flooding initiators, database file model.

DA-D3 unavailabilities, and certain (Met Cat II) operator actions. This causes the distribution calculated by Uncert to be narrower than it would be had error factors been included for these parameters.

This is a finding because it relates to the results of the parametric uncertainty.

QU-E3 1-45: No discussion of the results The JUL12Rl model None, gap has (Met Cat Ill) of the Parametric Uncertainty uncertainty analysis provided been closed for Analysis was found. No calculation in the Quantification and the JUL12Rl of the Error Factor (95%/50%) was Summary Notebookwas model.

found. No statement regarding the updated to include a full reasonableness of the CAPT A discussion of uncertainty mean value was found.

including the provision of a mean value comparison This is a finding since it relates to table, additional uncertainty fundamental information necessary graphs for lCDF, lHE, for most application submittals.

2CDF, and 2HE, and a specific conclusion section discussing results, mean, and skewness.

QU-F3 6-40: No initiating event pie chart The Quantification and None, gap has (Met Cat IIIIII) was given for Unit 2 results. The Summary Notebook was been closed for Summary Notebook states that Unit revised to include initiating the JUL12Rl 2 results are similar. No importance events pie charts for lCDF, model.

measures for components or 2DF, lHE, and 2HE.

systems were given in the documentation.

This is a suggestion to enhance the model documentation.

TABLE2 to PLA-7193 Page 58 of 60 SUPPORTING REQUIREMENTS MEETING CAPABILITY CATEGORY II OR GREATER WITH ASSOCIATED FACTS AND OBSERVATIONS SUPPORTING F&O #,DESCRIPTION OF RESOLUTION IMPACT REQUIREMENT GAP, AND SIGNIFICANCE LE-ClO 3-5: Per discussion with plant staff, The process for evaluating None, gap has (Met Catll) although a review of sequences was accident sequence been closed for not performed "after the fact" to try progression was added to the the JUL12Rl Related SRs to further reduce LERF. Rather, the Quantification and Summary model.

LE-C12 event trees were built to credit Notebook.

(Met Cat II) equipment operation and operator actions as would be warranted given the conditions. The sequences were reviewed in this process. That is, only actions from the control room and equipment that could be reasonably assumed for success were credited. In this fashion, no additional engineering analyses were warranted to support continued operation of equipment or operator actions during accident progression that could reduce LERF.

It was determined that this process should be documented in the AS/SC notebook.

It was determined that documentation of the process that was utilized to evaluate the accident sequence procession is necessary to affirm for PRA applications that an evaluation was performed.

LE-F3 1-43: Understanding LERF Open item Documentation (Met Cat Illlllll) uncertainty in the Susquehanna item. No impact.

model would be improved by having LERF related assumptions were clearly identified and listed in a single place (e.g., a section of the summary notebook or elsewhere).

This is a suggestion because it applies to documentation only.

TABLE2 to PLA-7193 Page 59 of 60 SUPPORTING REQUIREMENTS MEETING CAPABILITY CATEGORY II OR GREATER WITH ASSOCIATED FACTS AND OBSERVATIONS SUPPORTING F&O #,DESCRIPTION OF RESOLUTION IMPACT REQUIREMENT GAP, AND SIGNIFICANCE LE-GS 2-4: Appendix E, Section E.6 of the Section E is related to None, gap has (Met Cat Ifllflll)

Summary Notebook evaluates the quantification limitations, been closed for limitations of the LERF evaluations and would not be appropriate the JUL12R1 related to the quantification for incorporation of model.

process.

limitations due to modeling choices. Therefore, Section This does not address the 2.10.1 was added to the limitations of the LERF analysis JUL12R1 Quantification and due to assumptions or modeling Summary Notebook for a choices.

discussion of potential limitations that could This is a suggestion to provide a influence LERF results in more complete description of the applications.

LERF analysis limitations for applications.

IFPP-Al 6-1: Based on discussion in Section Open item Negligible effect (Met Cat Ifllfiii) 3.1 and contents of Appendix C of on model results.

the Internal Flooding notebook, See PRA Impact Related SRs flood areas are based on plant from Internal IFPP-B1 rooms, which appear to be Flooding (Met Cat 1/II/III) generally independent of other discussion, areas regarding flood propagation.

which precedes Table 1.

Many buildings and structures were eliminated from further consideration on the basis that they do not contain any SSCs modeled in the PRA, as identified in Section 3.1.1.2 However, it is not clear if there exists a potential for a flood in one of these areas to propagate to a building/area that does contain flood susceptible PRA equipment.

Based on discussions with PRA staff and review of the plant layout drawing, only the Radwaste building is connected to the main portion of the plant.

This is a suggestion as the list of screened buildings appears reasonable.

TABLE2 to PLA-7193 Page 60 of 60 SUPPORTING REQUIREMENTS MEETING CAPABILITY CATEGORY II OR GREATER WITH ASSOCIATED FACTS AND OBSERVATIONS SUPPORTING F&O#, DESCRIPTION OF RESOLUTION IMPACT REQUIREMENT GAP, AND SIGNIFICANCE IFQU-A2 1-28: Consider using the FRANX Open item None,F&O (Met Cat 1/IIIIII) or other declarative modeling tool suggests a way for the injection of flooding of adding flood initiators (and other spatially initiators to the oriented initiators, such as internal model and is an fire, or external event initiators enhancement.

such as seismic).

This is a suggestion, since there is no requirement to use a declarative modeling technique for injection of flooding initiators.

MU-Cl 1-27: There is no requirement to Open item None,F&O (Met Cat IIIIIIII) issue the development model as the addresses the updated model based upon the PRA Related SRs quantitative impact on PRA Maintenance and MU-E1 applications (such as MSPI) in the Update (Met Cat I/II/III)

Susquehanna model maintenance Procedure.

procedures.

This is a finding because it causes the SR to be not met.

(This F &0 may be a finding, however, both of the associated SRs were noted as met.)