Text

Expedited Seismic Evaluation Process Report - Fukushima Near-Term Task Force Recommendation 2.1
	ML15049A502
Person / Time
Site:	Hatch
Issue date:	12/30/2014
From:	Pierce C R; Southern Co, Southern Nuclear Operating Co
To:	; Document Control Desk, Office of Nuclear Reactor Regulation
References
	NL-14-1989
	Download: ML15049A502 (72)
	v • d • e

Charles R. Pierce Regulatory Affairs Director December 30, 2014 Docket Nos.: 50-321 50-366 Southern Nuclear Operating Company, Inc. 40 Inverness Center Parkway Post Office Box 1295 Birmingham , AL 35201 Tel 205.992.7872 Fax 205.992.7601 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D. C. 20555-0001 NL-14-1989 Edwin I. Hatch Nuclear Plant-Units 1 and 2 Expedited Seismic Evaluation Process Report -Fukushima Near-Term Task Force Recommendation 2.1

References:

1. NRC Letter, Request for Information Pursuant to Title 10 of the Code of Federal Regulations 50.54(f) Regarding Recommendations 2.1 , 2.3, and 9.3 of the Near-Term Task Force Review of Insights from the Fukushima Daiichi Accident , dated March 12, 2012. 2. NEI Letter to NRC, Proposed Path Forward for NTTF Recommendation 2.1: Seismic Reevaluations , dated April 9, 2013. 3. NRC Letter , Electric Power Research Institute Final Draft Report XXXXXX , " Seismic Evaluation Guidance:

Augmented Approach for the Resolution of Fukushima Near-Term Task Force Recommendation 2.1: Seismic" as an Acceptable Alternative to the March 12 , 2012 , Information Request for Seismic Reevaluations , dated May 7 , 2013. Ladies and Gentlemen:

On March 12 , 2012, the Nuclear Regulatory Commission (NRC) issued a request for information pursuant to 10 CFR 50.54(f) associated with the recommendations of the Fukushima Near-Term Task Force (NTTF) (Reference 1). Enclosure 1 of Reference 1 requested each licensee to reevaluate the seismic hazards at their sites us i ng present-day NRC requirements and guidance , and to identify actions taken or planned to address plant-specific vulnerabilities associated with the updated seismic hazards. The NRC endorsed the Electric Power Research Institute (EPRI) Report, Seismic Evaluation Guidance:

EPRI Guidance for the Resolution of Fukushima Near-Term Task Force Recommendation 2.1: Seismic, Draft Report , as an acceptable alternative to the information requested in Reference 1 by letter dated May 7 , 2013 (Reference 3). In its endorsement, the NRC staff determined that the EPRI Guidance will provide an important demonstration of seismic margin and expedite plant safety enhancements through evaluations and potential near-term modifications of certain core and containment cooling equipment while more comprehensive plant seismic risk evaluations are performed.

Reference 3 also provided NRC staff approval of the schedule modifications requested by U. S. Nuclear Regulatory Commission NL-14-1989 Page2 Reference

2. Based on the modified schedule, Central and Eastern United States (CEUS) licensees are required to submit the reports resulting from the Expedited Seismic Evaluation Process (ESEP) by December 2014. Accordingly, the Edwin I. Hatch Nuclear Plant ESEP Report for Units 1 and 2 is provided in Enclosure

1. A table of outstanding actions required for completion of the ESEP activities, with a schedule for completion of each, is provided in Enclosure

2. This letter contains NRC commitments described in Enclosure

3. If you have any questions, please contact John Giddens at 205.992.7924.

Mr. C. R. Pierce states he is the Regulatory Affairs Director for Southern Nuclear Operating Company, is authorized to execute this oath on behalf of Southern Nuclear Operating Company and, to the best of his knowledge and belief, the facts set forth in this letter are true. . ...... __ _

c.-R. "-" C. R. Pierce Regulatory Affairs Director CRP/JMG/TWS

':1(. to and subscribed before me day of

'2014. My commission expires: I/ l. /z.ot8

Enclosures:

1. Expedited Seismic Evaluation Process (ESEP) Report 2. Required Actions and Schedule for Completion of ESEP Activities

3. Table of Regulatory Commitments cc: Southern Nuclear Operating Company Mr. S. E. Kuczynski, Chairman, President

& CEO Mr. D. G. Bost, Executive Vice President

& Chief Nuclear Officer Mr. D. R. Vineyard, Vice President-Hatch Mr. M. D. Meier, Vice President-Regulatory Affairs Mr. D. R. Madison, Vice President-Fleet Operations Mr. B. J. Adams, Vice President-Engineering Mr. G. L. Johnson, Regulatory Affairs Manager-Hatch RType: CHA02.004 U. S. Nuclear Regulatorv Commission Mr. V. M. McCree, Regional Administrator Mr. R. E. Martin, NRR Senior Project Manager-Hatch Mr. D. H. Hardage, Senior Resident Inspector-Hatch State of Georgia Mr. J. H. Turner, Director-Environmental Protection Division Edwin I. Hatch Nuclear Plant -Units 1 and 2 Expedited Seismic Evaluation Process Report -Fukushima Near-Term Task Force Recommendation

2.1 Enclosure

1 Expedited Seismic Evaluation Process (ESEP) Report

MPR ASSOCIATES INC. ENGINEERS MPR-4121 Revision 0 December 23, 2014 Plant Hatch Units 1 and 2 Expedited Seismic Evaluation Process (ESEP) Report QUALITY ASSURANCE DOCUMENT This document has been prepared, reviewed, and approved in accordance with the Quality Assurance requirements of 10CFR50 Appendix Band/or ASME NQA-1, as specified in the MPR Nuclear Quality Assurance Program. Prepared for Southern Nuclear Operating Company

.MPR ASSOCIATES INC. ENGINEERS Plant Hatch Units 1 and 2 Expedited Seismic Evaluation Process (ESEP) Report MPR-4121 Revision 0 December 23,2014 QUALITY ASSURANCE DOCUMENT This document has been prepared, reviewed, and approved in accordance with the Quality Assurance requirements of 10CFR50 Appendix Band/or ASME NQA-1, as specified in the MPR Nuclear Quality Assurance Program. Prepared by: Q Kimberly A. Keithline Reviewed by: H. Mojtaba ghbaei Approved by:

Caroline S. Schlaseman Prepared for Southern Nuclear Operating Company 320 KING STREET ALEXANDRIA, VA 22314-3230 703-519*0200 FAX: 703-519*0224 http:\\www.mpr.com Revision 0 MPR-4121 RevisionO Affected Pages All RECORD OF REVISIONS Description Initial issue iii Contents Executive Summary ......................................................................................................

1 1 Purpose and Objective

.........................................................................................

2 2 Brief Summary of the FLEX Seismic Implementation Strategies

.....................

3 3 Equipment Selection Process and ESEL. ........................................................... 6

3.1 Equipment

Selection Process and ESEL ......................................................................

6 3 .1.1 ESEL Development

.............................................................................................

6 3 .1.2 Power Operated Valves .......................................................................................

7 3.1.3 Pull Boxes ...........................................................................................................

7 3.1.4 Termination Cabinets ..........................................................................................

8 3.1.5 Critical Instrumentation Indicators

.....................................................................

8 3.1.6 Phase 2 and Phase 3 Piping Connections

............................................................

8 3.1.7 Inaccessible Valve Interlocks

..............................................................................

8 3.2 Justification for Use of Equipment that is not the Primary Means for FLEX lmplementation

.......................................................................................................................

8 4 Ground Motion Response Spectrum (GMRS) ....................................................

9 4.1 Plot of GMRS Submitted by Licensee ..........................................................................

9 4.2 Comparison to SSE .....................................................................................................

1 0 5 Review Level Ground Motion (RLGM) ...............................................................

14 5.1 Description of RLGM Selected ..................................................................................

14 5.2 Method to Estimate In-Structure Response Spectrum (ISRS) ....................................

16 6 Seismic Margin Evaluation Approach ...............................................................

17 6.1 Summary of Methodologies Used ..............................................................................

17 6.2 HCLPF Screening Process ..........................................................................................

17 6.3 Seismic Walk down Approach ....................................................................................

18 MPR-4121 RevisionO

6.3.1 Walkdown

Approach ........................................................................................

18 6.3.2 Application ofPrevious Walkdown Information

..............................................

19 6.3.3 Significant Walkdown Findings ........................................................................

20

6.4 HCLPF

Calculation Process .......................................................................................

20 6.5 Functional Evaluation ofRelays .................................................................................

20 6.6 Tabulated ESEL HCLPF Values (Including Key Failure Modes) .............................

21 7 Inaccessible Items ..............................................................................................

22 7.1 Identification of ESEL Items Inaccessible for W alkdown .........................................

22 7.2 Planned W alkdown!Evaluation Schedule/Close Out.. ................................................

23 8 ESEP Conclusions and Results ........................................................................

24 8.1 Supporting Information

..............................................................................................

24 8.2 Identification of Planned Modifications

.....................................................................

25 8.3 Modification Implementation Schedule .....................................................................

25 8.4 Summary of Regulatory Commitments

......................................................................

25 9 References

..........................................................................................................

26 Attachment A: Plant Hatch Unit 1 ESEL. ..............................................................

A-1 Attachment 8: Plant Hatch Unit 2 ESEL. ..............................................................

B-1 MPR-4121 RevisionO v

Tables Table 4-1. GMRS for Plant Hatch Units 1 and 2 ...........................................................................

1 0 Table 4-2. Horizontal Design Basis Earthquake (DBE) for Plant Hatch Unit 1 ............................

12 Table 4-3. Horizontal Design Basis Earthquake (DBE) for Plant Hatch Unit 2 ............................

13 Table 5-1. Plant Hatch IPEEE RLE ...............................................................................................

15 Table A-1. Plant Hatch Unit 1 ESEL Items and HCLPF Results ...............................................

A-1 Table B-1. Plant Hatch Unit 2 ESEL Items and HCLPF Results ................................................

B-1 MPR-4121 RevisionO vi Figures Figure 2-1. Electrical Diagram for Plant Hatch FLEX Strategies (Reference

3) ...........................

.4 Figure 2-2. Flow Diagram for Plant Hatch FLEX Strategies (Reference

3) ..................................

.5 Figure 4-1. Plant Hatch GMR.S ........................................................................................................

9 Figure 4-2. Horizontal Design Basis Earthquake (DBE) and GMR.S for Plant Hatch ..................

11 Figure 5-1. Hatch IPEEE RLE Compared to the Unit 1 and Unit 2 DBEs and the GMR.S ...........

15 MPR-4121 RevisionO vii Executive Summary Plant Hatch Units 1 and 2 have performed the Expedited Seismic Evaluation Process (ESEP) as an interim action in response to the NRC's 50.54(f) letter (Reference 1). The purpose was to demonstrate seismic margin through a review of a subset of the plant equipment that can be relied upon to protect the reactor core following beyond design basis seismic events. The ESEP was performed using the methodologies in the NRC-endorsed industry guidance in EPRI 3002000704, Seismic Evaluation Guidance:

Augmented Approach for the Resolution of Fukushima Near-Term Task Force Recommendation 2.1 -Seismic (Reference 2). As a result of the ESEP, no modifications have been identified as necessary to meet ESEP acceptance criteria specified in Reference

2. MPR-4121 RevisionO 1

1 Purpose and Objective Following the accident at the Fukushima Dai-ichi nuclear power plant resulting from the March 11,2011, Great Tohoku Earthquake and subsequent tsunami, the Nuclear Regulatory Commission (NRC) established a Near Term Task Force (NTTF) to conduct a systematic review ofNRC processes and regulations and to determine if the agency should make additional improvements to its regulatory system. The NTTF developed a set of recommendations intended to clarify and strengthen the regulatory framework for protection against natural phenomena.

Subsequently, the NRC issued a 50.54(f) letter on March 12, 2012 (Reference 1), requesting information to assure that these recommendations are addressed by all U.S. nuclear power plants. The 50.54(f) letter requests that licensees and holders of construction permits under 1 0 CFR Part 50 reevaluate the seismic hazards at their sites against present -day NRC requirements and guidance.

Depending on the comparison between the reevaluated seismic hazard and the current design basis, further risk assessment may be required.

Assessment approaches acceptable to the staff include a seismic probabilistic risk assessment (SPRA) or a seismic margin assessment (SMA). Based upon the assessment results, the NRC staff will determine whether additional regulatory actions are necessary.

This report describes the Expedited Seismic Evaluation Process (ESEP) undertaken for Plant Hatch Units 1 and 2. The intent of the ESEP is to perform an interim action in response to the NRC's 50.54(f) letter (Reference

1) to demonstrate seismic margin through a review of a subset of the plant equipment that can be relied upon to protect the reactor core following beyond design basis seismic events. The ESEP is implemented using the methodologies in the NRC-endorsed industry guidance in EPRI 3002000704, Seismic Evaluation Guidance:

Augmented Approach for the Resolution of Fukushima Near-Term Task Force Recommendation 2.1-Seismic (Reference 2). The objective of this report is to provide summary information describing the ESEP evaluations and results. The level of detail provided in the report is intended to enable NRC to understand the inputs used, the evaluations perfonned, and the decisions made as a result of the interim evaluations.

MPR-4121 RevisionO 2

2 Brief Summary of the FLEX Seismic Implementation Strategies The Plant Hatch FLEX strategies for Reactor Core Cooling and Containment Function are summarized below. This summary is derived from the Plant Hatch Overall Integrated Plan (OIP) in Response to the March 12,2012, Commission Order EA-12-049 (Reference 3). During FLEX Phase 1, the primary strategy for reactor core cooling is to supply high quality water via reactor core isolation cooling (RCIC) with suction from the Condensate Storage Tank (CST). lfthe CST is depleted (in approximately 6-7 hours by analysis), suction will be taken from the torus. Reactor pressure is controlled using safety relief valves (SRVs) with DC control power and pneumatic pressure supplied by the station batteries and accumulators for each SRV. As torus temperature increases, operators reduce reactor pressure to 200-400 psig to provide margin to the heat capacity temperature limit curve. During FLEX Phase 2, reactor core cooling will continue to be maintained using RCIC. After depletion of the initial CST inventory and while RCIC is taking suction from the torus, the CST will be replenished using the portable FLEX pump and water from the Ultimate Heat Sink (Altamaha River). RCIC will continue to inject water from the torus until the torus level reaches the low level limit and suction must be re-aligned to the CST. The torus water level drops due to evaporation through the Hardened Containment Vent System (HCVS), which is operated to maintain containment parameters below design limits and RCIC operating parameters within acceptable limits. Reactor pressure will continue to be controlled using the SRVs. The 125V DC batteries will provide power for more than 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months without recharging.

As shown in Figure 2-1 (Reference 3), the FLEX 600 VDC diesel generators will be connected at approximately 10-12 hours to power two 125/250 VDC Battery Chargers per division, RCIC Controls, and other loads necessary for event mitigation and monitoring.

During FLEX Phase 3, reactor core cooling can be maintained using installed plant equipment and on-site portable FLEX equipment.

RCIC will be used to cool the core until reactor pressure is insufficient to drive the RCIC turbine, at which time the Phase 2 FLEX pump will be used to inject directly to the reactor using the RHRSW-RHR cross tie valves as shown in Figure 2-2 (Reference 3); this will be well after 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months per analysis . .MPR-4121 RevisionO 3

MPR-4 1 21 Revis i o n 0 ............... "" "'""""' (l:.ootu-u&asl......Ut-*

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- .,.,..,.,_ll Sf SNCH03*1 E 'J02 0 P Figure 2-1. Electrical Diagram for Plant Hatch FLEX Strategies (Reference

3) 4 MPR-4 1 2 1 R e vi s i o n 0 eoTS"P"'....., .sJ ;;:: <D RHRSW UNn 2 I NTAKC U"G l I lliV II .. I o L ...... i ... [jl 0 * ---------**-**--_j-"" L.-I-*--r----?.::r : _ _j ----. L ___ _..,.."" i I '"'" I i I i

-..::o JD't'" "' ..... I!] . e.l1 c;ca I. rU? ..... TI lllliA'ItCO Wf

--..... -. , .... .. (-') --ft---,......, t ,..,.

Figure 2-2. Flow Diagram for Plant Hatch FLEX Strategies (Reference

3) 5 3 Equipment Selection Process and ESEL The selection of equipment for the Expedited Seismic Equipment List (ESEL) followed the guidelines ofEPRI 3002000704 (Reference 2). The ESELs for Units 1 and 2, presented in Attachments A and B, respectively, are based on SNCH106:..PR-001 and SNCH106-PR-002 (References 4 and 5). 3.1 EQUIPMENT SELECTION PROCESS AND ESEL The ESEL component selection followed the EPRI guidance outlined in Section 3.2 of Reference

2. The selection of equipment to be included on the ESEL was based on installed plant equipment credited in the FLEX strategies during Phase 1, 2, and 3 mitigation of a Beyond Design Basis External Event (BDBEE), as outlined in the Plant Hatch Overall Integrated Plan (OIP) in Response to the March 12,2012, Commission Order EA-12-049 (Reference 3). The OIP provides the Plant Hatch FLEX mitigation strategy and serves as the basis for equipment selected for the ESEP. The Plant Hatch ESEL includes permanently installed plant equipment that could be relied upon to accomplish the core cooling and containment safety functions identified in Table 3-1 of Reference 2 in response to a beyond-design-basis earthquake.

Per Reference 2, the ESEL does not include portable or pre-staged FLEX equipment (not permanently installed) or equipment that is used only for recovery strategies.

The scope of equipment on the ESEL includes that required to support a single FLEX success path. Instrumentation monitoring requirements for core cooling and containment integrity functions are limited to those discussed in Reference

2. In accordance with Reference 2, the following structures, systems, and components were excluded from the ESEL:

Structures (e.g., reactor building and control building)

Piping, cabling, conduit, HV AC, and their supports

Manual valves and check valves

Power-operated valves not required to change state as part of the FLEX mitigation strategies

Nuclear steam supply system components (e.g., reactor pressure vessel and internals) 3.1.1 ESEL Development The ESEL was developed by reviewing the Plant Hatch FLEX OIP (Reference

3) to determine the major equipment involved in the FLEX strategies.

Plant drawings (e.g., Process and MPR-4121 RevisionO 6

Instrumentation Diagrams (P&IDs) and electrical one-line diagrams) were reviewed to specify the boundaries of the flow paths used in the FLEX strategies and to identify other components needed to support operation of the systems credited in the FLEX strategies.

Boundaries were established at an electrical or mechanical isolation device (e.g., isolation amplifier or valve) in branch circuits/branch lines off the defined strategy electrical or fluid flowpath.

P&IDs were the primary reference documents used to identify mechanical components and instrumentation needed for FLEX. Once the flow paths were identified, specific components were selected using the guidance in Reference

2. Electrical components needed to support FLEX were identified using one-line diagrams and schematics.

Based on this review, base list tables of components were developed for each of the methods credited with accomplishing key functions in the FLEX strategies.

The base list tables were then reviewed to determine which equipment should be included on the ESEL. Most of the equipment decisions were clearly outlined in the Reference 2 guidance; however, some judgments were necessary as discussed below. 3.1.2 Power Operated Valves Per the Reference 2 EPRI guidance, the ESEL does not need to include power-operated valves that are not required to change state as part of the FLEX mitigating strategies.

However, Reference 2 also states, "In addition to the physical failure modes (load path and anchorage) of specific pieces of installed equipment, functional failure modes of electrical and mechanical portions of the installed Phase 1 equipment should be considered (e.g., RCIC)." Because relay chatter could cause a functional failure, the following criteria were used to determine whether specific power-operated valves should be included on the ESEL:

Power operated valves in the primary success path will be included on the ESEL if they need to remain energized during Phase 1 in order to maintain core cooling and containment integrity (e.g., certain DC-powered valves).

Power operated valves not required to change state as part of the FLEX mitigation strategies may be excluded from the ESEL if they would be de-energized by the event that causes the Extended Loss of all AC Power (ELAP) event.

AC power-operated valves not required to change state as part of the Phase 1 FLEX mitigation strategies may be excluded from the ESEP if they are re-energized and operated during Phase 2 or 3 activities.

3.1.3 Pull Boxes Pull boxes were deemed unnecessary to add to the ESELs as these components provide completely passive locations for pulling or installing cables. No breaks or connections in the cabling are included in pull boxes. Pull boxes were considered part of the conduit and cabling, which are excluded in accordance with Reference

2. MPR-4121 RevisionO 7

3.1.4 Termination

Cabinets Although termination cabinets and junction boxes provide a passive function similar to pull boxes, they were included on the ESEL to ensure industry knowledge on panel/anchorage failure vulnerabilities is addressed.

3.1.5 Critical

Instrumentation Indicators Critical indicators and recorders are typically physically located on panels/cabinets and are included as separate components; however, seismic evaluation of the instrument indication may be included in the panel/cabinet seismic evaluation (rule-of-the-box).

3.1.6 Phase

2 and Phase 3 Piping Connections As noted in Section 3.2 ofReference 2, the scope of the ESEL is limited to installed plant equipment and FLEX equipment connections" and "the selection process for the ESEL should assume the FLEX strategies (modifications, equipment, procedures, etc.) have been implemented." Section 3.2 of Reference 2 also explains that "piping, cabling, conduit, HV AC, and their supports" are excluded from the ESEL scope. Therefore, piping and pipe supports associated with FLEX Phase 2 and Phase 3 connections are excluded from the scope of the ESEP evaluation.

Except as described in Sections 3.1 and 3 .1.2 above, valves required to change position to establish/maintain FLEX Phase 2 and Phase 3 flow paths (i.e., active valves) are included in the ESEL. 3.1.71naccessible Valve Interlocks Some components have interlocks that could potentially inhibit valve operation during Phase 2 or 3 of FLEX. Reference 2 specifically allows exclusion of interlock failures from the ESEL if plant procedures provide instructions for manual operation to ensure performance of the required FLEX function.

For valves that cannot be operated locally due to location in containment or high radiation areas, this statement is interpreted as allowing the interlocks in the control circuit to be bypassed to allow remote manual operation.

Therefore, these interlocks are excluded in Phase 3. 3.2 JUSTIFICATION FOR USE OF EQUIPMENT THAT IS NOT THE PRIMARY MEANS FOR FLEX IMPLEMENTATION All components on the ESEL for Plant Hatch Units 1 and 2 are associated with the primary FLEX strategies.

Therefore, since no alternate equipment is being used, no justification is needed. MPR-4121 RevisionO 8

4 Ground Motion Response Spectrum (GMRS) In response to the 50. 54( f) letter (Reference 1 ), SNC reevaluated the Plant Hatch seismic haz a rd in accordance with the NRC-endorsed industry guidance (Reference 6). 4.1 PLOT OF GM RS SUBMITTED BY LICENSEE The plot of the Plant Hatch GMRS submitted by SNC to the NRC in Reference 7 is shown in Figure 4-1. Table 4-1 contains the corresponding numerical values that were also included in Reference

7. The GMRS and Design Basis Earthquake (DB E) control point elevation is defined at Elevation 129 feet , which is general plant grade. rr= 0 i 0; 1.0[+0 0 8j 1.0 E 0 1 u < l'D ... tl OJ c. U) MPR-41 2 1 R ev i s i o n 0 1. E*0 2 , I I ' I I I 0.1 I , , , , , ........ ..,_. ..... .. , ,, ... , ... .. ... , ... , ... , , ,.. . -. _. . '--.. , , , I ' , ..._ + ---*Me th o d 3 (1E*5 , -* M e[hod 3 GMR S -Me th o d 3 {1 E-4) 1 10 0 0 Figure 4-1. Plant Hatch GMRS 9 Table 4-1. GMRS for Plant Hatch Units 1 and 2 Frequency Spectral Frequency Spectral Frequency Spectral (Hz) Acceleration (Hz) Acceleration (Hz) Acceleration (g) (g) (g) 100 0.1422 12.5 0.2744 1*_,:_: ,1.00 0.2206 90.0 0.1422 10.0 0.3039 0.900 0.2171 80;0 0.1427 9.00 0.3111 0.800 0.2009 * .. *: ' 70.0 0.1438 cC:C. *:g;*O() 0.3142 700 ., 0.1696 60.0 0.1452 7.00 0.3164 0.600 0.1452 50.0 0.1478 6.00 0.3203 0.500 0.1113 45.0 0.1508 5.00 0.3118 . 0.400 0.0737 40.0 0.1532 4.00 0.3080 0.300 0.0580 35.0 0.1583 J..OO 0.3029 0.200 0.0437 . 30.0 0.1666 2.50 0.3096 . 0.167 0.0346 25 .* 0 0.1790 2.00 0.3158 0.125 0.0203 .***. 20.0 0.2027 *1;;5:0. 0.2844 I <UOO 0.0145 . 15.0 0.2459 . 1.25 0.2654 4.2 COMPARISON TO SSE The plots of the Plant Hatch Unit 1 DBE and Unit 2 DBE submitted by SNC to the NRC in Reference 7 are shown in Figure 4-2 along with the GMRS. Tables 4-2 and 4-3 contain the corresponding numerical values that were also included in Reference

7. Note that Reference 7 uses DBE and SSE interchangeably for Plant Hatch. MPR-4121 RevisionO 10 MPR-4 1 2 1 Rev i sio n 0 1

-GMRS -Unit 2 DBE -Unit 1 DBE 1 10 100 Frequency (Hz) Figure 4-2. Horizontal Design Basis Earthquake (DBE) and GMRS for Plant Hatch 11 Table 4-2. Hori z ontal Des i g n Bas i s Earthquake (DBE) f o r Plant Hatch Uni t 1 Frequency (Hz) MPR-4121 Revision 0 33.33 28.67 25.0 0 22.22 2 0.00 16.67 14.29 12.50 11.11 10.00 8.00 6.67 5.00 4.00 Spectral Acceleration (g) 0.150 0.150 0.15 0 0.150 0.150 0.150 0.150 0.156 0.163 0.169 0.188 0.206 0.216 0.221 Frequency (Hz) Spectral Acceleration (g) 3.33 0.221 2.86 0.225 2.50 0.22 1 2.22 0.216 2.00 0.2 0 6 1.67 0.1 78 1.43 0.165 1.25 0.150 1.11 0.133 1.00 0.128 0.67 0.092 0.50 0.069 0.33 0.051 0.10 0.015 12 Table 4-3. Horizontal Design Basis Earthquake (DBE) for Plant Hatch Unit 2 Frequency (Hz) MPR-4121 Revision 0 100.00 16.00 14.30 12.50 11.10 10.00 8.30 7.70 6.00 5.00 4.00 3.00 Spectral Acceleration (g) 0.150 0.150 0.165 0.180 0.200 0.210 0.240 0.260 0.320 0.320 0.320 0.320 Frequency (Hz) Spectral Acceleration (g) 2.50 0.320 2.00 0.320 1.50 0.240 1.25 0.200 1.00 0.160 0.70 0.110 0.50 0.080 0.33 0.050 0.22 0.036 0.14 0.015 0.10 0.007 13 5 Review Level Ground Motion (RLGM) Section 4 of Reference 2 states that the ESEP may be performed using either the GMRS or a linearly scaled version of the SSE (DBE for Plant Hatch) that bounds the GMRS between 1 and 1 0 Hz. In many cases, scaling the SSE facilitates a more expedient evaluation by allowing use of existing SSE-based in-structure response spectra (ISRS) that are simply scaled by the same factor (Scenarios 2 and 3 in Figure 1-2 of Reference 2). However, for surface-mounted items (where ISRS estimates are not necessary), plants may decide to use the GMRS instead of the scaled SSE (Scenario 4 in Figure 1-2 ofReference 2). The Plant Hatch ESEP was performed using either the GMRS (for two surface-mounted items) or the RLGM used previously by the combined A-46/IPEEE Program at Plant Hatch as discussed below, which is consistent with the guidance in Reference

2.

5.1 DESCRIPTION

OF RLGM SELECTED As discussed in Reference 7 and documented in the 1991 EPRI Report NP-721 7 (Reference 8), a full EPRI Seismic Margin Assessment (SMA) was previously performed for Plant Hatch Unit 1 as a trial BWR assessment of the EPRI SMA methodology.

That SMA project included a soil failure evaluation and a full relay evaluation and was peer reviewed by several review panels. As part of the Independent Plant Examination of External Events (IPEEE), a focused scope SMA and a full SQUG GIP relay review were performed for Plant Hatch Unit 2 (Reference 9). The Review Level Earthquake (RLE) for both of those SMAs was a median NUREG/CR-0098 type ground response spectrum anchored to 0.3g peak ground acceleration (PGA) as shown in Table 5-1 (Reference 7). As described in Reference 8, a soil-structure interaction analysis was performed and new ISRS were developed for the IPEEE RLE. For comparison purposes, Figure 5-1 includes the Hatch IPEEE RLE, the Hatch Unit 1 DBE, the Hatch Unit 2 DBE, and the Hatch GMRS. Above 1Hz, the Hatch Units 1 and 2 IPEEE RLE spectrum is at least two times or larger than the Hatch Unit 1 DBE and the Hatch Unit 2 DBE, and is about twice the HatchGMRS.

To facilitate an early start (prior to obtaining the GMRS) and timely completion of the ESEP, the IPEEE RLE was used as the ESEP review level ground motion (RLGM) for most of the equipment in Plant Hatch Units 1 and 2. Only the surface-mounted condensate storage tanks (CSTs), which did not require ISRS, were evaluated to the GMRS. MPR-4121 RevisionO 14

-IPEEE R LE -G M R S -U n i t 2 DBE :§ -Unit1 DBE r l rn l I I II u ::;, I I II i 0.4 +---------,--

1 U1 II 0.2 0.1 1 10 100 Frequency (Hz) Figure 5-1. Hatch IPEEE RLE Compared to the Un it 1 and Unit 2 DBEs and the GMRS MPR-4121 Re v i s ion 0 T able 5-1. Plant Hatch IPEEE RLE Frequency (Hz) Spectra l Acce l erat i on (g) 100 0.3 33 0.3 20 0.38 1 2.5 0.45 10 0.54 8 0.637 2 0.637 1 0.3 0.5 0.1 5 1 5

5.2 METHOD

TO ESTIMATE IN-STRUCTURE RESPONSE SPECTRUM (ISRS) For structure-mounted equipment, the ESEP used the IPEEE RLE in-structure response spectra (ISRS). As stated in Section 5.1, the IPEEE ISRS are based on ground motion equal to or larger than twice the Hatch Unit 1 and Hatch Unit 2 DBEs. MPR-4121 RevisionO 16 6 Seismic Margin Evaluation Approach The objective of the ESEP is to demonstrate that the ESEL items have sufficient seismic capacity to meet or exceed the seismic demand associated with the RLGM. Section 5 of Reference 2 provides guidance for characterizing the seismic capacity by determining a high confidence of low probability of failure (HCLPF) using either the Seismic Margin Assessment (SMA) methodology ofEPRI NP-6041-SL (Reference 1 0) or the fragility analysis methodology ofEPRI 1R-103959 (Reference 12). The Plant Hatch ESEP used the EPRINP-6041-SL SMA approach, consistent with the earlier combined A-46/IPEEE Program. The HCLPF capacity is based on the weakest or most seismically limiting attribute of the equipment (structural, anchorage, or functional).

The HCLPF evaluation considers the dynamic response of the equipment, but the HCLPF value is expressed in terms of a peak ground acceleration (PGA) to provide a common point of reference relative to the RLGM. Per Reference 2, ESEL items have sufficient seismic capacity if the HCLPF capacity is equal to or greater than the RLGM PGA. 6.1

SUMMARY

OF METHODOLOGIES USED Seismic Margin Assessments (SMAs) were performed for Plant Hatch Units 1 and 2 in the early 1990s and are documented in References 8 and 9. Those SMAs were performed as part of the combined A-46/IPEEE program at Plant Hatch and included many of the items on the ESEL. As part of the ESEP, the Seismic Review Team (SRT) evaluated each accessible item on the ESEL for seismic capacity, anchorage, and relay functionality (when a FLEX methodology relay was identified in the ESEL). (Inaccessible items are discussed in Section 7.1.) The ESEP walk.downs and evaluations were documented in Screening and Evaluation Work Sheets (SEWS), which include checklists that were developed from Appendix F of EPRI NP-6041-SL (Reference 10). Each member of the SR T was trained as a SQUG Seismic Capability Engineer in accordance with the Generic Implementation Procedure (GIP) and trained in the use ofEPRI NP-6041-SL.

Selected team members also took the EPRI HCLPF course, which was developed for the ESEP implementation and is based on EPRI NP-6041-SL.

6.2 HCLPF

SCREENING PROCESS ESEL items were evaluated for the Hatch IPEEE RLE, which is a median NUREG/CR-0098 type ground response spectrum anchored to 0.3g PGA, as shown in Figure 5-1. The only exception to this approach was used for the CSTs, as described below. The 5 percent damped Peak Spectral Acceleration of the Hatch IPEEE RLE allowed the use of the first column (<0.8g PSA) ofReference 10 Table 2-4 "Summary ofEquipment and Subsystems Screening Criteria for Seismic Margin Evaluation" in establishing HCLPFs greater than or equal to the RLE for ESEL MPR-4121 RevisionO 17 items. Anchorage evaluations were performed using the in-structure response spectra developed for the A-46/IPEEE program's RLE (shown in Figure 5-1). For the CSTs, the HCLPFs were established using the rigorous methodology of Reference 10 Appendix H "Flat-Bottom Vertical Fluid Storage Tanks" and additional information provided during the EPRI HCLPF course (Reference 11 ). The review level earthquake for the CST HCLPF evaluations was the GMRS. 6.3 SEISMIC WALKDOWN APPROACH 6.3.1 Walkdown Approach ESEP walkdowns were performed in accordance with the criteria provided in Section 5 of Reference 2, which refers to Reference 10 for the Seismic Margin Assessment process. Pages 2-26 through 2-30 ofReference 10 describe the seismic walkdown guidance, including the following key points. MPR-4121 RevisionO "The SRT [Seismic Review Team] should "walk by" 100% of all components which are reasonably accessible and in non-radioactive or low radioactive environments.

Seismic capability assessment of components which are inaccessible, in high-radioactive environments, or possibly within contaminated containment, will have to rely more on alternate means such as photographic inspection, more reliance on seismic reanalysis, and possibly, smaller inspection teams and more hurried inspections.

A 100% "walk by" does not mean complete inspection of each component, nor does it mean requiring an electrician or other technician to de-energize and open cabinets or panels for detailed inspection of all components.

This walkdown is not intended to be a QA or QC review or a review of the adequacy of the component at the SSE level. If the SRT has a reasonable basis for assuming that the group of components are similar and are similarly anchored, then it is only necessary to inspect one component out of this group. The "similarity-basis" should be developed before the walkdown during the seismic capability preparatory work (Step 3) by reference to drawings, calculations or specifications.

The one component or each type which is selected should be thoroughly inspected which probably does mean de-energizing and opening cabinets or panels for this very limited sample. Generally, a spare representative component can be found so as to enable the inspection to be performed while the plant is in operation.

At least for the one component of each type which is selected, anchorage should be thoroughly inspected.

The walkdown procedure should be performed in an ad hoc manner. For each class of components the SRT should look closely at the first items and compare the field configurations with the construction drawings and/or specifications.

If a one-to-one correspondence is found, then subsequent items do not have to be inspected in as great a detail. Ultimately the walkdown becomes a "walk by" of the component class as the SRT becomes 18 confident that the construction pattern is typical. This procedure for inspection should be repeated for each component class; although, during the actual walkdown the SRT may be inspecting several classes of components in parallel.

If serious exceptions to the drawings or questionable construction practices are found then the system or component class must be inspected in closer detail until the systematic deficiency is defined. The 100% "walk by" is to look for outliers, lack of similarity, anchorage which is different from that shown on drawings or prescribed in criteria for that component, potential Sf [Seismic Interaction 1] problems, situations that are at odds with the team members 'past experience, and any other areas of serious seismic concern. If any such concerns surface, then the limited sample size of one component of each type for thorough inspection will have to be increased.

The increase in sample size which should be inspected will depend upon the number of outliers and different anchorages, etc., which are observed.

It is up to the SRT to ultimately select the sample size since they are the ones who are responsible for the seismic adequacy of all elements which they screen from the margin review. Appendix D gives guidance for sampling selection. " 6.3.2 Application of Previous Walk down Information Many ESEL items were previously walked down during the Plant Hatch A-46/IPEEE program using an IPEEE RLE that was equal to or greater than twice the DBEs. Consistent with the guidance in References 2 and 10, the A-46/IPEEE documentation for some electrical items was used to eliminate the need for electrical bus outages and minimize the risk of tripping the plant by not opening some energized electrical equipment that had been opened during the A-46/ IPEEE program. Specifically, some ESEL items evaluated during the A-46/IPEEE program and shown to have a seismic capacity greater than or equal to the IPEEE RLE were evaluated but not opened to view anchorage.

The ESEP walkdowns were performed to confirm consistency of these items with their A-46/IPEEE condition and address seismic capacity questions that could be answered without opening the equipment.

Based on this information, which included documentation from the A-46/IPEEE SEWS, NTTF 2.3 seismic information, drawings, and calculations, the SRTs were able to evaluate the equipment capacity and anchorage without electrical bus outages or risk of tripping the plant by opening these items. Previous walkdown information was also used for evaluation of inaccessible equipment, as discussed in Section 7.1. 1 EPRI 3002000704 (Reference

2) page 5-4 limits the ESEP seismic interaction reviews to "nearby block walls" and "piping attached to tanks" which are reviewed "to address the possibility of failures due to differential displacements." Other potential seismic interaction evaluations are "deferred to the full seismic risk evaluations performed in accordance with EPRI1025287 (Reference 6)." MPR-4121 RevisionO 19

6.3.3 Significant

Walkdown Findings Consistent with guidance from Reference 10, no significant seismic issues were identified at Plant Hatch during the final ESEP seismic walkdowns.

During initial ESEP seismic walkdowns, one significant seismic issue was identified:

Anchorage for the nitrogen ambient vaporizer for each unit (1 T48-B004 and 2T48-B002) was degraded at the time of the initial walkdown and condition reports (CRs) were written to resolve the problem. These components were re-evaluated after repairs were made and the HCLPFs for the anchorages now meet or exceed the Hatch IPEEE RLE. Smaller issues identified during the initial walkdowns (e.g., corrosion on anchor bolts for the Unit 1 outside nitrogen storage tank (1 T48-A001))

were entered as condition reports, resolved, and then re-evaluated to confirm that the components have HCLPFs that meet or exceed the Hatch IPEEE RLE. Some block walls were identified in the proximity ofESEL equipment.

During the A-46/IPEEE combined program, these block walls were assessed for their structural adequacy to withstand the seismic loads resulting from the Hatch IPEEE RLE. 6.4 HCLPF CALCULATION PROCESS Consistent with the Reference 10 deterministic/SMA methodology, the Plant Hatch ESEP acceptance criteria were that the equipment's structural/functional capacity, anchorage capacity, and relay functional capacity (when required) exceeded the seismic demand of the Hatch IPEEE RLE. Therefore, when these criteria were met, the HCLPF was defmed as being at least as high as the IPEEE RLE (0.3 g PGA), and calculation of specific HCLPF values in excess of 0.3 g PGA was not warranted.

Specific HCLPF values were calculated for the CSTs so that both the tank capacities (e.g., shell failure modes) and anchorage capacities (e.g., cast-in-place L-bolts and anchor chairs) could be evaluated using the CDFM methodology in Appendix H of Reference 10 and additional information provided during the EPRI HCLPF course (Reference 11 ). The CSTs were evaluated using the GMRS instead of the IPEEE RLE. 6.5 FUNCTIONAL EVALUATION OF RELAYS Relays in four cabinets and three motor control centers (total for both units) required functional evaluations.

Each relay was evaluated using the SMA relay evaluation criteria in Section 3 of Reference

10. Seismic qualification test-based capacities were available for these specific relays in Plant Hatch documentation.

For the twelve relays contained in four cabinets, capacity to demand evaluations were performed using the Plant Hatch relay seismic capacities and the IPEEE RLE ISRS scaled with the Reference 10 in-cabinet amplification factors. The four relays contained in the three MCCs were qualified during dynamic testing ofthe MCCs; therefore, the in-cabinet amplification was included within the testing. In each case, the capacity exceeded the demand. MPR-4121 RevisionO 20 The ESEP relay functional evaluations were documented in the SEWS packages for these four cabinets and three motor control centers. 6.6 TABULATED ESEL HCLPF VALUES (INCLUDING KEY FAILURE MODES) Tabulated ESEL HCLPF values are provided in Attachment A for Unit 1 and in Attachment B for Unit 2. The following notes apply to the information in the tables.

Items which screened out of an explicit functional capacity analysis using EPRI NP-6041-SL (Reference 1 0) Table 2-4 have a HCLPF greater than or equal to the RLGM; therefore, the HCLPF is shown as "2:RLGM" in Tables A-1 and B-1. This is consistent with the SMA methodology of not calculating an explicit HCLPF capacity if the criteria for functional capacity (e.g., EPRI NP-6041-SL Table 2-4) are met and instead providing results as meeting or exceeding the seismic input level selected as the RLGM.

It is unknown whether anchorage is the controlling failure mode for items that were screened for their functional capacity because the functional capacity may or may not be higher than the anchorage capacity.

The one exception to this is that large, flat-bottom vertical tanks (e.g., the Condensate Storage Tanks (CSTs)) were evaluated using a methodology that includes all failure modes (i.e., anchorage failure modes and tank shell failure modes). The HCLPF values for these tanks are reported in Tables A-1 and B-1.

Equipment containing FLEX Methodology

("FM") relays was assessed for relay functional capacity as described in Section 6.5 of this report. Because it is not known whether the capacity of the equipment containing the relay, the equipment's anchorage, or the relay's capacity is the controlling HCLPF, the HCLPF is shown as "2:RLGM" in Tables A-1 and B-1, and the Notes/Comments" column identifies the presence ofFM relay(s).

MPR-4121 RevisionO 21 7 Inaccessible Items 7.1 IDENTIFICATION OF ESEL ITEMS INACCESSIBLE FOR WALKDOWN The Plant Hatch ESELs contain about 70 items (total for both units) that are located in either the Drywells or Locked High Radiation Areas. In order to avoid dose (i.e., maintaining radiation exposure ALARA) and to reduce impact on refueling outages scheduled in 2015 and 2016, these ESEL items were evaluated to determine whether a walkdown was necessary.

The inaccessible/high dose equipment includes the following classes:

Accumulators (for the SRVs)

Air-Operated Valves (SRVs)

MOVs

Temperature Elements

Junction Boxes

Pneumatic System Filters and PCV (Unit 2 only) Appendix D of Reference 10 provides information regarding "Sampling." Specifically, on page D-1, "sampling is technically valid for identical or similar components if there is evidence that the components are manufactured and installed in a consistent manner .... In some instances access is severely limited by radioactive environments and limited sampling is the only practical method of conducting a walkdown." Much of the inaccessible/high dose equipment was previously evaluated during the A-46/IPEEE program. Although 6 of the 18 SRV accumulators on the ESEL were not previously evaluated for the Plant Hatch IPEEE RLE, sampling is a practical approach for concluding that they also have HCLPFs that meet or exceed the ESEP RLGM. Like the SRV accumulators, most of the SRVs were also evaluated during the A-46/IPEEE program, and were found to meet SMA criteria for the IPEEE RLE. The SRVs, however, have been replaced since the A-46/IPEEE, or they are scheduled to be replaced in the next refueling outage (RFO). The replacement valves should be at least as robust as the SRVs that were evaluated during the A-46/IPEEE program. Additionally, in accordance with Reference 10, Table 2-4, active valves screen out from further SMA evaluations at the five percent-damped peak spectral acceleration for the Hatch IPEEE RLE ( <0.8g). Therefore, additional ESEP walkdowns and the associated dose are not warranted.

A similar argument is made for the 8 MOVs (total for both units), where half of the MOVs were explicitly included in the A-46/IPEEE program. In accordance with Reference 10, Table 2-4, MPR-4121 RevisionO 22 active valves screen out from further SMA evaluations at the five percent-damped peak spectral acceleration for the Hatch IPEEE RLE ( <0.8g). Therefore, additional ESEP walkdowns and the associated dose are not warranted.

The temperature elements in the Drywell are considered to be represented by the ten temperature elements that were walked down (total for both units), and no seismic issues were identified; therefore, the inaccessible temperature elements do not merit specific walkdowns.

Junction boxes were not part of the A-46/IPEEE program, but dozens have been walked down during the ESEP, and no seismic issues have been identified; therefore, junction boxes in the drywell do not merit walkdowns.

Finally, there are three inaccessible/high dose devices related to the Unit 2 Drywell pneumatic system: two filters and one pressure control valve (PCV). Filters are passive devices and considered seismically rugged, as are typical PCV s. The Unit 1 pneumatic system filters and the PCV are in a Reactor Building diagonal (outside the drywell) and were walked down; no seismic issues were identified for these small passive devices. None of these devices merit a Drywell entry and the dose associated with performing walkdowns for the ESEP. 7.2 PLANNED WALKDOWN/EVALUATION SCHEDULE/CLOSE OUT Walkdowns have been completed for installed accessible items on the ESELs. Section 7.1 discusses the disposition for inaccessible items. ESEL items that have not been installed or for which FLEX modifications have not been completed as of the time of this report will be evaluated after installation or modification per the SMA methodology outlined in Reference

10. See Section 8.4 and Tables A-1 and B-1 for details. MPR-4121 RevisionO 23 8 ESEP Conclusions and Results 8.1 SUPPORTING INFORMATION Plant Hatch has performed the ESEP as in interim action in response to the NRC's 50.54(t) letter (Reference 1 ). It was performed using the methodologies in the NRC endorsed guidance in EPRI 3002000704 (Reference 2). The ESEP provides an important demonstration of seismic margin and expedites plant safety enhancements through evaluations and potential near-term modifications of plant equipment that can be relied upon to protect the reactor core following beyond design basis seismic events. The ESEP is part of the overall Plant Hatch response to NRC's 50.54(t) letter (Reference 1). On March 12,2014, NEI submitted to the NRC results of a study (Reference

13) of seismic core damage risk estimates based on updated seismic hazard information as it applies to operating nuclear reactors in the Central and Eastern United States (CEUS). The study concluded that specific seismic hazards show that there has not been an overall increase in seismic risk for the fleet ofU.S. plants based on the re-evaluated hazard. As such, the "current seismic design of operating reactors continues to provide a safety margin to withstand potential earthquakes exceeding the seismic design basis." The NRC's May 9, 2014 NTIF 2.1 Screening and Prioritization letter (Reference

14) concluded that the "fleetwide seismic risk estimates are consistent with the approach and results used in the GI-199 safety/risk assessment." The letter also stated that "As a result, the staffhas confirmed that the conclusions reached in GI-199 safety/risk assessment remain valid and that the plants can continue to operate while additional evaluations are conducted." An assessment of the change in seismic risk for Plant Hatch was included in the fleet risk evaluation submitted in the March 12, 2014 NEI letter (Reference 13); therefore, the conclusions in the NRC's May 9letter (Reference

14) also apply to Plant Hatch. In addition, the March 12, 2014 NEI letter (Reference

13) provided an attached "Perspectives on the Seismic Capacity of Operating Plants," which (1) assessed a number of qualitative reasons why the design of SSCs inherently contain margin beyond their design level, (2) discussed industrial seismic experience databases of performance of industry facility components similar to nuclear SSCs, and (3) discussed earthquake experience at operating plants. The fleet of currently operating nuclear power plants was designed using conservative practices, such that the plants have significant margin to withstand large ground motions safely. This has been borne out for those plants that have actually experienced significant earthquakes.

The seismic design process has inherent (and intentional) conservatisms which result in significant seismic margins within structures, systems and components (SSCs ). These conservatisms are reflected in several key aspects of the seismic design process, including:

MPR-4121 RevisionO 24

Safety factors applied in design calculations

Damping values used in dynamic analysis of SSCs

Bounding synthetic time histories for in-structure response spectra calculations

Broadening criteria for in-structure response spectra

Response spectra enveloping criteria typically used in SSC analysis and testing applications

Response spectra based frequency domain analysis rather than explicit time history based time domain analysis

Bounding requirements in codes and standards

Use ofminimum strength requirements of structural components (concrete and steel)

Bounding testing requirements, and

Ductile behavior of the primary materials (that is, not crediting the additional capacity of materials such as steel and reinforced concrete beyond the essentially elastic range, etc.). These design practices combine to result in margins such that the SSCs will continue to fulfill their functions at ground motions well above the SSE. 8.2 IDENTIFICATION OF PLANNED MODIFICATIONS No modifications have been identified as necessary to meet ESEP acceptance criteria.

8.3 MODIFICATION

IMPLEMENTATION SCHEDULE No modifications have been identified for the items that have been evaluated.

SNC intends to comply with the ESEP schedule (Attachment 2 of Reference

15) for any modifications determined to be necessary for items to be walked down as identified in Sections 7.2 and 8.4. 8.4

SUMMARY

OF REGULATORY COMMITMENTS Please refer to the Table of Regulatory Commitments that will accompany this report. MPR-4121 RevisionO 25 9 References

1. NRC Letter to All Power Reactor Licensees et al., "Request for Information Pursuant to Title 10 ofthe Code ofFederal Regulations 50.54(f) Regarding Recommendations 2.1, 2.3, and 9.3 of the Near-Term Task Force Review oflnsights from the Fukushima Dai-ichi Accident," dated March 12,2012 [ADAMS Accession Number ML12053A340].

2. EPRI Report 3002000704, "Seismic Evaluation Guidance:

Augmented Approach for the Resolution ofFukushima Near-Term Task Force Recommendation 2.1-Seismic," Electric Power Research Institute, May 2013. 3. SNC Nuclear Letter NL-14-0593, "Edwin I. Hatch Nuclear Plant Units 1 and 2 Third Month Status Report of the Implementation of the Requirements of the Commission Order with Regard to Mitigation Strategies for Beyond-Design-Basis External Events (EA-12-049)," dated August 26,2014. 4. ENERCON Engineering Report SNCH106-PR-001, Rev. 3, "Equipment Selection for the Expedited Seismic Evaluation Process for Southern Nuclear Operating Company, Inc., Hatch Nuclear Plant Unit No. 1." 5. ENERCON Engineering Report SNCH106-PR-002, Rev. 3, "Equipment Selection for the Expedited Seismic Evaluation Process for Southern Nuclear Operating Company, Inc., Hatch Nuclear Plant Unit No. 2." 6. EPRI Report 1025287, "Seismic Evaluation Guidance:

Screening, Prioritization and Implementation Details (SPID) for the Resolution of Fukushima Near-Term Task Force Recommendation 2.1: Seismic," Electric Power Research Institute, February 2013. 7. SNC Nuclear Letter NL-14-0343, "Edwin I. Hatch Nuclear Plant Units 1 and 2 Seismic Hazard and Screening Report for CEUS Sites," dated March 31,2014. 8. EPRI Report NP-7217. "Seismic Margin Assessment of the Edwin I. Hatch Nuclear Plant, Unit 1," Electric Power Research Institute, June 1991. 9. "Individual Plant Examination for External Events, Edwin I. Hatch Nuclear Plant, Units 1 and 2" (Response to Generic Letter 88-20, Supplement 4). 10. EPRI NP-6041-SL, "A Methodology for Assessment of Nuclear Power Plant Seismic Margin, Revision 1,** Electric Power Research Institute, August 1991. 11. Hardy, Greg and Dr. Robert Kennedy, "High Confidence of a Low Probability of Failure (HCLPF) Calculation Training," EPRI, (August 2013). MPR-4121 RevisionO 26

12. EPRI TR-1 03959, "Methodology for Developing Seismic Fragilities," Electric Power Research Institute, 1999. 13. NEI (A. Pietrangelo) letter to NRC (E. Leeds) dated March 12, 2014, "Seismic Risk Evaluations for Plants in the Central and Eastern United States." 14. NRC (E. Leeds) letter dated May 9, 2014, "Screening and Prioritization Results Regarding Information Pursuant to Title 10 ofthe Code of Federal Regulations 50.54(f) Regarding Seismic Hazard Re-Evaluations for Recommendation 2.1 of the Near-Term Task Force Review oflnsights from the Fukushima Dai-ichi Accident." 15. NEI (A. Pietrangelo) letter to NRC (D. Skeen) dated April9, 2013, "Proposed Path Forward for NTTF Recommendation 2.1: Seismic Reevaluations." 16. Dr. Robert Kennedy letter to Southern Company Services (D. Moore) dated August 13, 1993, "Re: Hatch Condensate Water Tank." 17. MPR Calculation No. 0380-0050-01, "Hatch Unit 2 Condensate Storage Tank," Revision 0, December 15, 2014. MPR-4121 RevisionO 27 Attachment A: Plant Hatch Unit 1 ESEL Table A-1. Plant Hatch Unit 1 ESEL Items and HCLPF Results ID 1821-A0038 1821-A003D 1821-A003E 1821-A003F 1821-A003G 1821-A003H 1821-A003J 1821-A003K 1821-A003L MPR-4121 RevisionO Equipment Description SRV AIR ACCUMULATOR SRV AIR ACCUMULATOR SRV AIR ACCUMULATOR SRV AIR ACCUMULATOR SRV AIR ACCUMULATOR SRV AIR ACCUMULATOR SRV AIR ACCUMULATOR SRV AIR ACCUMULATOR SRV AIR ACCUMULATOR Operating State Normal Desired Available Available Available Available Available Available Available Available Available Available Available Available Available Available Available Available Available Available HCLPF Screening Notes/Comments Results Inaccessible/High N/A Dose; See Section 7.1 Inaccessible/High N/A Dose; See Section 7.1 Inaccessible/High N/A Dose; See Section 7.1 Inaccessible/High N/A Dose; See Section 7.1 Inaccessible/High N/A Dose; See Section 7.1 Inaccessible/High N/A Dose; See Section 7.1 Inaccessible/High N/A Dose; See Section 7.1 Inaccessible/High N/A Dose; See Section 7.1 Inaccessible/High N/A Dose; See Section 7.1 A-1 ID 1B21-F013B 1B21-F013D 1B21-F013E 1B21-F013F 1B21-F013G 1B21-F013H 1B21-F013J 1B21-F013K 1B21-F013L 1B21-N091B 1B21-N691B 1B21-R604B MPR-4121 RevisionO Equipment Description MSL "A" RPV SRV (ADS) MSL "B" RPV SRV (ADS) MSL "B" RPV SRV (ADS) MSL "C' RPV SRV (ADS) MSL "C" RPV SRV (LLSL) MSL "D" RPV SRV (LLSL) MSL "D" RPV SRV (ADS) MSL "B" RPV SRV (ADS) MSL 'C' RPV SRV (ADS) RPV Levels 2 & 1 LT-Div II -Batt LPCI RX Water Level MTU LIS -Div II-Batt RPV Level (Hot Leg) Ll -Div II -Batt Operating State HCLPF Screening Notes/Comments Normal Desired Results Inaccessible/High Closed Closed/Open N/A Dose; See Section 7.1 Inaccessible/High Closed Closed/Open N/A Dose; See Section 7.1 Inaccessible/High Closed Closed/Open N/A Dose; See Section 7.1 Inaccessible/High Closed Closed/Open N/A Dose; See Section 7.1 Inaccessible/High Closed Closed/Open N/A Dose; See Section 7.1 Inaccessible/High Closed Closed/Open N/A Dose; See Section 7.1 Inaccessible/High Closed Closed/Open N/A Dose; See Section 7.1 Inaccessible/High Closed Closed/Open N/A Dose; See Section 7.1 Inaccessible/High Closed Closed/Open N/A Dose; See Section 7.1 Operating Operating RLGM Operating Operating Operating Operating A-2 ID 1C32-KGSSC 1C32-K902 1C32-NOOSC 1C32-RGOSC 1C82-POOl 1C82-P002 lEll-BOOlA lEll-F003A lEll-FOOS lEll-FOlSA lEll-F017A lEll-F048A lEll-F068A lEll-F073A MPR-4121 RevisionO Equipment Description FWC RX Pressure Transmitter C -Div II -Batt RX WTR LVL RFP TRIP C FWC RX Water Level PT-Div II-Batt FWC RX PI -Div II -Batt REMOTE SHUTDOWN PANEL-ESl REMOTE SHUTDOWN PANEL RHR HEAT EXCHANGER RHR HX OUTLT 16" GATE MOV Shutdown Cooling Outboard I so Inboard Injection Gate MOV (RHR lnbd lnj Vlv) Outboard Injection Gate MOV (RHR Outbd lnj Vlv) RHR HX Bypass Globe MOV (Hx Bypass Vlv) HX SW FLOW CONTROLLER MOV RHRSW TO RHR CROSSTIE MOV Operating State HCLPF Screening Notes/Comments Normal Desired Results Operating Operating Operating Operating Operating Operating Operating Operating RLGM Available Available Available Available Available Available Open Closed RLGM Inaccessible/High Closed Closed N/A Dose; See Section 7.1 Inaccessible/High Closed Open N/A Dose; See Section 7.1 Inaccessible/High Open Throttled N/A Dose; See Section 7.1 Open Closed Closed Closed Closed Closed/Open A-3 ID 1E11-F07SA 1E11-N027B 1E51-AOOl 1E51-BOOl 1E51-COOl 1ES1-C002 1E51-F008 1E51-F010 1E51-F012 1ES1-F013 1E51-F015 lESl-F019 1E51-F029 1E51-F031 MPR-4121 RevisionO Equipment Description RHRSW TO RHR CROSSTIE MOV RHR HX Discharge TE-Div II RCIC BAROMETRIC CONDENSER RCIC LUBE OIL COOLER RCIC REACTOR MAKEUP PUMP RCIC TURBINE STEAM SUPPLY ISO GATE VLV Pump Suction 6" Gate MOV {CST Suction Valve) RCIC PUMP DISCHARGE GATE MOV Pump Disch 4" Gate MOV {Pump Discharge Valve) RCIC COOLING WATER PCV Min Flow 2" Bypass MOV {RCIC Min-Flow Valve) PUMP SUCTION GATE VALVE {Suppression Pool Suction) PUMP SUCTION GATE VALVE {Suppression Pool Suction) Operating State HCLPF Screening Notes/Comments Normal Desired Results Closed Closed/Open Operating Operating Standby Operating RLGM Standby Operating Standby Operating Standby Operating

<!:RLGM Inaccessible/High Open Open N/A Dose; See Section 7.1 Open Open/Closed Open Open <!:RLGM Closed Open RLGM Open Operating

<!:RLGM Closed Closed/Open

<!:RLGM Closed Closed/Open A-4 ID lESl-F033 lESl-F045 lESl-F046 lESl-F523 lESl-F524 lESl-N060 lESl-N061 lHll-P601 lHll-P602 lHll-P603 lHll-P605B lHll-P612 lHll-P621 MPR-4121 RevisionO Equipment Description RCIC BAROMETRIC CONDENSER RELIEF VALVE RCIC STEAM SUPPLY GLB MOV COOLING WATER GLOBE VALVE MOV (From Pump Discharge)

Steam Supply 3" Governing Gate HOV (RCIC Governor Valve) Steam Supply 3" Trip Throttle MOV (RCIC Trip & Throttle Valve) RCIC CST LO LS -Div I -Batt RCIC CST LO LS -Div I -Batt RX & CTMT CLG & ISO PNL RWCU & RECIRC PNL Reac Control BN BD -Panel CLS lE Analog Signal Converter/IS Panel FW/Recirc INST Panel RCIC RELAY VB Operating State HCLPF Screening Notes/Comments Normal Desired Results Standby Standby Closed Open Closed Open Open Operating RLGM Open Open Operating Operating Operating Operating Available Available RLGM Available Available Available Available Available Available Available Available Includes FM Available Available Relays; See Section 6.5 A-5 ID 1H11-P622 1H11-P623 1H11-P628 1H11-P654 1H11-P655 1H11-P691B 1H11-P700 1H11-P925 1H11-P926 1H11-P927 1H11-P928 1H21-P004 1H21-POSl 1H21-P173 MPR-4121 RevisionO Equipment Description Inboard lso Valve Vert Panel Outboard lso Valve Vert Panel AUTO DEPRESS RELAY VB Gas Treat Vent Vert BD -Panel BEARING TEMP & BAT MON VB Analog Signal Converter Panel ANAL/VENT

& LEAK DET PNL ATTS ECCS MCR Panel ATTS ECCS MCR Panel ATTS ECCS Trip Unit Cabinet-Panel ATTS ECCS Trip Unit Cabinet-Panel RV LEVEL/PRESS LOC PNL A RCIC SYSTEM ESl PANEL SHUTDOWN INSTRUMENT PANEL Operating State HCLPF Screening Notes/Comments Normal Desired Results Available Available

RLGM Includes FM Available Available

RLGM Relays; See Section 6.5 Available Available

RLGM Available Available

RLGM Available Available

RLGM Available Available

RLGM Available Available

RLGM Available Available

RLGM Available Available

RLGM Available Available

RLGM Available Available

RLGM Available Available

RLGM Available Available

RLGM Available Available

RLGM A-6 ID 1H21-P405A 1Pll-A100 1P52-A027A 1P52-A027B 1P52-F1312 1P70-A001 1P70-D008A 1P70-D009A 1P70-F001A 1P70-F103A 1R22-S016 1R22-S017 1R23-S003 MPR-4121 RevisionO Equipment Description RX VESSEL INST RACK Condensate Storage Tank AIR ACC (BKUP AIR ACCUMULATOR TANK A) AIR ACC (BKUP AIR ACCUMULATOR TANK B) Relief Valve N2 Cylinder Supply Manifold Overpressure Protection D/W N2 SYSTEM RECEIVER 100 MICRON NOM FILTER 5 MICRON NOM FILTER D/W PNEUMATIC N2 SPLY AOV D/W PNEUMATIC HEADER PCV 125/250VDC Switchgear 1A 125/250VDC Switchgear 1B 600VAC Bus 1C -Switchgear/XFM R Operating State HCLPF Screening Notes/Comments Normal Desired Results Available Available

<!:RLGM Screened to GMRS Available Available 0.15g instead of IPEEE RLE; Reference 16 Not Yet Installed; Available Available N/A See Sections 7.2 & 8.4 Not Yet Installed; Available Available N/A See Sections 7.2 & 8.4 Not Yet Installed; Standby Standby N/A See Sections 7.2 & 8.4 Available Available

<!:RLGM Available Available

<!:RLGM Closed Open <!:RLGM Operating Operating

<!:RLGM Energized Energized

<!:RLGM A-7 ID 1R23-S004 1R24-S021 1R24-S021A 1R24-S022 1R25-S001 1R25-S002 1R25-S064 1R25-S065 1R25-S066 1R25-S067 1R25-S069 1R25-S094 1R25-S106 MPR-4121 RevisionO Equipment Description 600VAC Bus 1D-Switchgear/XFMR 250VDC MCC 1A 250VDC MCC 1A-1 250VDC MCC 1B 125VDC Distribution Cabinet 1A 125VDC Distribution Cabinet 1B 120/208VAC Instrument Bus 1A-Div I 120/208VAC Instrument Bus 1B-Div II 120VAC CRITICAL INSTRUMENT CABINET 1A 120VAC CRITICAL INSTRUMENT CABINET 1B Emergency Lighting Cabinet -Div II Emergency Lighting Cabinet -Div II 125VDC Distribution Cabinet 1E Operating State HCLPF Screening Notes/Comments Normal Desired Results Energized Energized Includes FM Energized Energized Relays; See Section 6.5 Includes FM Energized Energized Relays; See Section 6.5 Energized De-Energized Energized Energized Energized Energized RLGM Available Available Available Available Not Yet Installed; Energized Energized N/A See Sections 7.2 & 8.4 Not Yet Installed; Energized Energized N/A See Sections 7.2 & 8.4 Energized Energized RLGM Energized Energized Energized Energized A-8 ID 1R26-M031A 1R26-M031B 1R26-M031C 1R26-M031D 1R26-M132 1R26-M133 1R26-M136 1R26-M137 1R26-M139 1R26-M140 1R42-S001A 1R42-S001B MPR-4121 RevisionO Equipment Description 12SVDC THROWOVER SW 1A 12SVDC THROWOVER SW 1B 12SVDC THROWOVER SW 1C 125VDC THROWOVER SW 1D FLEX FUSED DISCONNECT SWITCH 1A FLEX FUSED DISCONNECT SWITCH 1B FLEX TRANSFER SWITCH 1A FLEX TRANSFER SWITCH 1B FLEX TRANSFER SWITCH 1D FLEX TRANSFER SWITCH 1E 125/2SOVDC Station Battery 1A 125/2SOVDC Station Battery 1B Operating State HCLPF Screening Notes/Comments Normal Desired Results Standby/ Standby/

Closed Closed Standby/ Standby/

Closed Closed Not Yet Installed; Standby Standby N/A See Sections 7.2 & 8.4 Not Yet Installed; Standby Standby N/A See Sections 7.2 & 8.4 Not Yet Installed; Normal Normal N/A See Sections 7.2 & 8.4 Not Yet Installed; Normal Normal N/A See Sections 7.2 & 8.4 Not Yet Installed; Normal Normal N/A See Sections 7.2 & 8.4 Not Yet Installed; Normal Normal N/A See Sections 7.2 & 8.4 Energized Energized RLGM Energized Energized A-9 ID 1R42-S026 1R42-S027 1R42-S029 1R42-S030 1R44-S006 1R44-S007 1T47-K600 1T47-K602 1T47-K603 1T47-K604 1T47-K605 1T47-NOOlA MPR-4121 RevisionO Equipment Description Battery Charger lA-Div I Battery Charger lB -Div I Battery Charger 10 -Div II Battery Charger lE -Div II 250VDC/120VACINVERTER lA 250VDC/120VAC INVERTER lB SIGNAL CONVERTER R/V NOOlA,B SIGNAL CONV R/V NOOlM, N003 SIG CONV R/V NOOS, N007 SIG CONV R/V NOlO SIGNAL CONV R/V B009A Inlet Air TE-Div II Operating State HCLPF Screening Notes/Comments Normal Desired Results FLEX Mod Not Yet Energized Energized N/A Complete; See Sections 7.2 & 8.4 FLEX Mod Not Yet Energized Energized N/A Complete; See Sections 7.2 & 8.4 Energized Energized O!:RLGM Energized Energized RLGM Not Yet Installed; Energized Energized N/A See Sections 7.2 & 8.4 Not Yet Installed; Energized Energized N/A See Sections 7.2 & 8.4 Operating Operating Operating Operating Operating Operating Operating Operating RLGM Operating Operating RLGM Inaccessible/High Operating Operating N/A Dose; See Section 7.1 A-10 ID 1T47-NOOlB 1T47-NOOlM 1T47-N003 1T47-NOOS 1T47-N007 1T47-NOlO 1T47-R612 1T48-AOOl 1T48-8004 1T48-F072 1T48-F075 MPR-4121 Revision 0 Equipment Description DW CLG Dome Area TE-Div II I B009A&B Inlet Air TE-Div II DW CLG Midlevel Area TE-Divll DW Lower Level Area TE-Div II DW Lower Level Area TE-Div II Sacrificial Shield Top TE-Div II DW CLG CRD/Torus Area TR -Divll NITROGEN STORAGE TANK N2 TANK AMBIENT VAPORIZER 8004 DISCH LINE RELIEF VALVE 8004 DISCHARGE PCV (N2 system) Operating State HCLPF Screening Notes/Comments Normal Desired Results Inaccessible/High Operating Operating N/A Dose; See Section 7.1 Inaccessible/High Operating Operating N/A Dose; See Section 7.1 Inaccessible/High Operating Operating N/A Dose; See Section 7.1 Inaccessible/High Operating Operating N/A Dose; See Section 7.1 Inaccessible/High Operating Operating N/A Dose; See Section 7.1 Inaccessible/High Operating Operating N/A Dose; See Section 7.1 Operating Operating 2: RLGM Repaired under Available Available 2: RLGM CAP and re-walked down; See Section 6.3.3. Repaired under Available Available 2: RLGM CAP and re-walked down; See Section 6.3.3. Standby Standby 2: RLGM Operating Operating 2: RLGM A-ll ID 1T48-F082 1T48-F318 1T48-F319 1T48-F320 1T48-F326 1T48-F408 1T48-K608B 1T48-K609B 1T48-K621B 1T48-K623B 1T48-N008B 1T48-N009B 1T48-N0090 1T48-N009F MPR-4121 Revision 0 Equipment Description HCVS Vent Control AOV HCVS Containment Isolation AOV HCVS Containment Isolation AOV HCVS Containment Isolation AOV HCVS Containment Isolation AOV Relief Valve Argon Supply Overpressure Protection OW Pressure lnst IN-Oiv II OW/Torus Pressure lnst IN-Oiv II TORUS AIR TEMP RN Torus Levellnst IN-Div II Torus Midrange PT-Div II Torus Water TE-Oiv II Torus Water TE-Oiv II Torus Air TE-Oiv II Operating State HCLPF Screening Notes/Comments Normal Desired Results Closed Closed/Open

!:RLGM Closed Closed/Open

!:RLGM Closed Closed ::!:RLGM Closed Closed ::!:RLGM Closed Closed/Open

!:RLGM Not Yet Installed; Standby Standby N/A See Sections 7.2 & 8.4 Operating Operating

!:RLGM Operating Operating

!:RLGM A-12 ID 1T48-N009H 1T48-N020B 1T48-N021B 1T48-N023B 1T48-R607B 1T48-R609 1X86-S003 1X86-S004 ESS-11-J379 ESS-11-J423 ESS-1-J422 J614 J615 MPR-4121 RevisionO Equipment Description Torus Air TE-Div II DW Narrow Range PT-Div II Narrow Range Torus LT-Div II DW Midrange PT-Div II DW and Torus Narrow Range L/PR-Div II OW/Torus Midrange PR-Div II 600V FLEX Diesel Generator (FLEX Connection Box 1A) 600V FLEX Diesel Generator (FLEX Connection Box 1B) JUNCTION BOX JUNCTION BOX JUNCTION BOX JUNCTION BOX JUNCTION BOX Operating State HCLPF Screening Notes/Comments Normal Desired Results Operating Operating

RLGM Operating Operating

RLGM Not Yet Installed; Standby Standby N/A See Sections 7.2 & 8.4 Not Yet Installed; Standby Standby N/A See Sections 7.2 & 8.4 Available Available

RLGM Available Available

RLGM Inaccessible/High Available Available N/A Dose; See Section 7.1 Inaccessible/High Available Available N/A Dose; See Section 7.1 A-13 ID J617 J618 J619 J620 J621 J647 J648 TB1-1529-7 MPR-4121 RevisionO Equipment Description JUNCTION BOX JUNCTION BOX JUNCTION BOX JUNCTION BOX JUNCTION BOX JUNCTION BOX JUNCTION BOX TERMINATION BOX Operating State Normal Desired Available Available Available Available Available Available Available Available Available Available Available Available Available Available Available Available HCLPF Screening Notes/Comments Results Inaccessible/High N/A Dose; See Section 7.1 Inaccessible/High N/A Dose; See Section 7.1 Inaccessible/High N/A Dose; See Section 7.1 Inaccessible/High N/A Dose; See Section 7.1 Inaccessible/High N/A Dose; See Section 7.1 Inaccessible/High N/A Dose; See Section 7.1 Inaccessible/High N/A Dose; See Section 7.1 ::!:RLGM A-14 Attachment B: Plant Hatch Unit 2 ESEL ID 2821-A003A 2821-A0038 2821-A003C 2821-A003E 2821-A003F 2821-A003H 2821-A003K 2821-A003L 2821-A003M MPR-4121 RevisionO Table B-1. Plant Hatch Unit 2 ESEL Items and HCLPF Results Equipment Operating State HCLPF Screening Notes/Comments Description Normal Desired Results Inaccessible/High SRV AIR ACCUMULATOR Available Available N/A Dose; See Section 7.1 Inaccessible/High SRV AIR ACCUMULATOR Available Available N/A Dose; See Section 7.1 Inaccessible/High SRV AIR ACCUMULATOR Available Available N/A Dose; See Section 7.1 Inaccessible/High SRV AIR ACCUMULATOR Available Available N/A Dose; See Section 7.1 Inaccessible/High SRV AIR ACCUMULATOR Available Available N/A Dose; See Section 7.1 Inaccessible/High SRV AIR ACCUMULATOR Available Available N/A Dose; See Section 7.1 Inaccessible/High SRV AIR ACCUMULATOR Available Available N/A Dose; See Section 7.1 Inaccessible/High SRV AIR ACCUMULATOR Available Available N/A Dose; See Section 7.1 Inaccessible/High SRV AIR ACCUMULATOR Available Available N/A Dose; See Section 7.1 B-1 ID 2821-F013A 2821-F013B 2821-F013C 2821-F013E 2821-F013F 2B21-F013H 2821-F013K 2821-F013L 2821-F013M 2821-N091B 2B21-N691B 2821-R604B MPR-4121 RevisionO Equipment Description MSL "A" RPV SRV (ADS) MSL "B" RPV SRV (LLSL) MSL "C" RPV SRV (ADS) MSL "A" RPV SRV (ADS) MSL "B" RPV SRV (LLSL) MSL "D" RPV SRV (ADS) MSL "B" RPV SRV (ADS) MSL "B" RPV SRV (ADS) MSL 'C' RPV SRV (ADS) RPV Levels 2 & 1 LT-Div II -Batt LPCI RX Water Level MTU LIS -Div II -Batt RPV Level (Hot Leg) Ll -Div II -Batt Operating State Normal Desired Closed Closed/Open Closed Closed/Open Closed Closed/Open Closed Closed/Open Closed Closed/Open Closed Closed/Open Closed Closed/Open Closed Closed/Open Closed Closed/Open Operating Operating Operating Operating Operating Operating HCLPF Screening Notes/Comments Results Inaccessible/High N/A Dose; See Section 7.1 Inaccessible/High N/A Dose; See Section 7.1 Inaccessible/High N/A Dose; See Section 7.1 Inaccessible/High N/A Dose; See Section 7.1 Inaccessible/High N/A Dose; See Section 7.1 Inaccessible/High N/A Dose; See Section 7.1 Inaccessible/High N/A Dose; See Section 7.1 Inaccessible/High N/A Dose; See Section 7.1 Inaccessible/High N/A Dose; See Section 7.1 RLGM B-2 ID 2C32-IN02 2C32-KGSSC 2C32-Noose 2C32-RGOSC 2C82-POOl 2E11-BOOlA 2E11-F003A 2E11-F008 2E11-FOlSA 2E11-F017A 2E11-F048A 2E11-F068A 2E11-F073A 2E11-F075A lviPR-4121 RevisionO Equipment Description RX WTR LVL RFP TRIP C FWC RX Pressure Transmitter C-Div II -Batt FWC RX Water Level PT -Div II-Batt FWC RX PI -Div II -Batt REMOTE S/D PANEL RHR HEAT EXCHANGER RHR HX OUTLT 16" GATE MOV Shutdown Cooling Outboard lso Inboard Injection Gate MOV (RHR lnbd lnj Vlv) Outboard Injection Gate MOV (RHR Outbd lnj Vlv) RHR HX Bypass Globe MOV (Hx Bypass Vlv) HX SW FLOW CONTROLLER MOV RHRSW CROSSTIE VALVE RHRSW CROSSTIE VALVE Operating State HCLPF Screening Notes/Comments Normal Desired Results Operating Operating

!:RLGM Operating Operating

!:RLGM Available Available

<!:RLGM Open Closed ::!:RLGM Inaccessible/High Closed Closed N/A Dose; See Section 7.1 Inaccessible/High Closed Open N/A Dose; See Section 7.1 Inaccessible/High Open Throttled N/A Dose; See Section 7.1 Open Closed ::!:RLGM Closed Closed ::!:RLGM Closed Closed/Open

!:RLGM Closed Closed/Open

!:RLGM B-3 ID 2E11-N027B 2E51-A001 2E51-B001 2E51-COOl 2E51-C002 2E51-F008 2E51-F010 2E51-F012 2E51-F013 2E51-F015 2E51-F019 2E51-F022 2E51-F029 2E51-F031 MPR-4121 RevisionO Equipment Description RHR HX Discharge TE-Div II RCIC BAROMETRIC CONDENSER RCIC LUBE OIL COOLER RCIC REACTOR MAKEUP PUMP RCIC TURBINE STEAM SUPPLY ISO GATE VLV Pump Suction 6" Gate MOV (CST Suction Valve) RCIC PUMP DISCHARGE GATE MOV Pump Disch 4" Gate MOV (Pump Discharge Valve) RCIC COOLING WATER PCV Min Flow 2" Bypass MOV {RCIC Min-Flow Valve) TEST THROTILE GLOBE VALVE PUMP SUCTION GATE VALVE PUMP SUCTION GATE VALVE Operating State HCLPF Screening Notes/Comments Normal Desired Results Operating Operating RLGM Standby Operating RLGM Standby Operating Standby Operating RLGM Standby Operating RLGM Inaccessible/High Open Open N/A Dose; See Section 7.1 Open Open/Closed RLGM Open Open Closed Open RLGM Open Operating RLGM Closed Closed/Open Closed Closed Closed Closed/Open RLGM Closed Closed/Open RLGM B-4 ID 2E51-F033 2E51-F045 2E51-F046 2E51-F523 2E51-F524 2E51-N060 2E51-N061 2Hll-P601 2Hll-P602 2Hll-P603 2Hll-P605B 2Hll-P612 2Hll-P621 MPR-4121 RevisionO Equipment Description RCIC BAROMETRIC CONDENSER RELIEF VALVE RCIC STEAM SUPPLY GLB MOV COOLING WATER GLOBE VALVE MOV (RHR Suction Valve) Steam Supply 3" Governing Gate HOV (RCIC Governor Valve) Steam Supply 3" Trip Throttle MOV (RCIC Trip & Throttle Valve) RCIC CST LO LS -Div I -Batt RCIC CST LO LS -Div I -Batt RX & CTMT CLG & ISO PNL RWCU & RECIRC PNL Reac Control BN BD -Panel CLS lE Analog Signal Converter/IS Panel FW/Recirc INST Panel RCIC RELAY VB Operating State HCLPF Screening Notes/Comments Normal Desired Results Standby Standby :i::RLGM Closed Open :i::RLGM Closed Open :i::RLGM Open Operating

i::RLGM Open Open :i::RLGM Operating Operating

i::RLGM Operating Operating

i::RLGM Available Available

RLGM Available Available

i::RLGM Available Available

i::RLGM Includes FM Available Available

i::RLGM Relays; See Section 6.5 B-5 ID 2Hll-P622 2Hll-P623 2Hll-P628 2Hll-PGSO 2Hll-P654 2Hll-PGSS 2Hll-P656 2Hll-P691B 2Hll-P925 2Hll-P926 2Hll-P927 2Hll-P928 2H21-P004 2H21-POSl MPR-4121 RevisionO Equipment Description INBD ISO VLV VERT PNL Outboard lso Valve Vert Panel AUTO DEPRESS RELAY VB TURB FDWTR & COND CON PNL Gas Treat Vent Vert BD -Panel BEARING TEMP & BAT MONVB STARTUP BOILER VERT PANEL Analog Signal Converter Panel ATTS ECCS Trip Unit Cabinet -Panel ATTS ECCS MCR Panel ATTS ECCS Trip Unit Cabinet -Panel ATTS ECCS Trip Unit Cabinet -Panel RV LEVEL/PRESS LOC PNL A RCIC SYSTEM 2E51 PANEL Operating State HCLPF Screening Notes/Comments Normal Desired Results Available Available Includes FM Available Available Relays; See Section 6.5 Available Available Available Available Available Available RLGM Available Available RLGM Available Available Available Available Available Available Available Available Available Available Available Available Available Available Available Available RLGM B-6 ID 2H21-P0 53 2H21-P255 2H21-P40SA 2JE1891 2JE2712 2JE2798 2JM7873 2P11-A001 2P52-A027A 2P52-A027B 2P52-F1228 2P70-D008A 2P70-D009A MPR-4121 RevisionO Equipment Description RCICTESTVALVE PI PANEL DG FUEL PMP&MOV CONT PNL RX VESSEL INST RACK JUNCTION BOX JUNCTION BOX JUNCTION BOX JUNCTION BOX Condensate Storage Tank BKUP AIR ACCUMULATOR TANKA BKUP AIR ACCUMULATOR TANKB Relief Valve N2 Cylinder Supply Manifold Overpressure Protection 100 MICRON NOM FILTER 5 MICRON NOM FILTER Operating State HCLPF Screening Notes/Comments Normal Desired Results Available Available

<!:RLGM Available Available Available Available

<!:RLGM Available Available Available Available Available Available

<!:RLGM Inaccessible/High Available Available N/A Dose; See Section 7.1 Screened to GMRS Available Available 0.18g instead of IPEEE RLE; Ref.17 Not Yet Installed; Available Available N/A See Sections 7.2 & 8.4 Not Yet Installed; Available Available N/A See Sections 7.2 & 8.4 Not Yet Installed; Standby Standby N/A See Sections 7.2 & 8.4 Inaccessible/High Available Available N/A Dose; See Section 7.1 Inaccessible/High Available Available N/A Dose; See Section 7.1 B-7 ID 2P70-F103A 2R11-S004 2R20M-POOl 2R22-S016 2R22-S017 2R23-S003 2R23-S004 2R24-S021 2R24-S022 2R24-S025 2R25-SOOl 2R25-S002 2R25-S029 MPR-4121 RevisionO Equipment Description D/W PNEUMATIC HEADER PCV 600-120/208V LTG & PWR TX FUSE BOX 125/250VDC Switchgear 2A 125/2SOVDC Switchgear 2B 600VAC Bus 2C-Switchgear/XFMR 600VAC Bus 2D-Switchgear/XFMR 250VDC MCC 2A 250VDC MCC 2B D/G BLDG 600/208V MCC 2A 12SVDC Distribution Cabinet 2A 12SVDC Distribution Cabinet 2B 120/208V DIST PANEL 2J Operating State HCLPF Screening Notes/Comments Normal Desired Results Inaccessible/High Operating Operating N/A Dose; See Section 7.1 Energized Energized Available Available RLGM Energized Energized Energized Energized Energized Energized RLGM Energized Energized RLGM Includes FM Energized Energized Relays; See Section 6.5 Energized De-Energized lA lA Energized; Energized; 7E 7E Energized Energized/

/Standby Standby Energized Energized Energized Energized RLGM Energized Energized/

/Standby Standby B-8 ID 2R25-S064 2R25-S065 2R25-S066 2R25-S067 2R25-S069 2R25-S094 2R25-S130 2R26-M031A 2R26-M031B 2R26-M031C 2R26-M031D 2R26-M126 2R26-M127 MPR-4121 RevisionO Equipment Description 120/208VAC Instrument Bus 2A-Div I 120/208VAC Instrument Bus 2B -Div II 120VAC Critical Instrument Cabinet 2A 120VAC Critical Instrument Cabinet 2B Emergency Lighting Cabinet -Divll Emergency Lighting Cabinet -Div II 125VDC Distribution Cabinet 2E 125VDC THROWOVER SW 2A 125VDC THROWOVER SW 2B 125VDC THROWOVER SW 2C 125VDC THROWOVER SW 20 FLEX Transfer Switch 2A FLEX Transfer Switch 2B Operating State HCLPF Screening Notes/Comments Normal Desired Results Available Available Available Available Not Yet Installed; Energized Energized N/A See Sections 7.2 & 8.4 Not Yet Installed; Energized Energized N/A See Sections 7.2 & 8.4 Energized Energized Energized Energized Energized Energized Standby/ Standby/

Closed Closed Standby/ Standby/ Closed Closed Standby/ Standby/ Closed Closed Standby/ Standby/ Closed Closed Not Yet Installed; Normal Normal N/A See Sections 7.2 & 8.4 Not Yet Installed; Normal Normal N/A See Sections 7.2 & 8.4 B-9 ID 2R26-M129 2R26-M130 2R26-M132 2R26-M133 2R27-S096 2R42-SOOlA 2R42-SOOlB 2R42-S026 2R42-S027 2R42-S029 2R42-S030 2R44-S006 MPR-4121 RevisionO Equipment Description FLEX Transfer Switch 20 FLEX Transfer Switch 2E FLEX Fused Disconnect Switch 2A FLEX Fused Disconnect Switch 2B LOCAL STARTER 2E11-F008 125/250VDC Station Battery 2A 125/250VDC Station Battery 2B Battery Charger 2A-Div I Battery Charger 2B -Div I Battery Charger 20 -Div II Battery Charger 2E -Div II 2SOVDC/120VAC FLEX Inverter 2A Operating State Normal Desired Normal Normal Normal Normal Standby Standby Standby Standby Energized De-Energized Energized Energized Energized Energized Energized Energized Energized Energized Energized Energized Energized Energized Energized Energized HCLPF Screening Notes/Comments Results Not Yet Installed; N/A See Sections 7.2 & 8.4 Not Yet Installed; N/A See Sections 7.2 & 8.4 Not Yet Installed; N/A See Sections 7.2 & 8.4 Not Yet Installed; N/A See Sections 7.2 & 8.4 RLGM FLEX Mod Not Yet N/A Complete; See Sections 7.2 & 8.4 FLEX Mod Not Yet N/A Complete; See Sections 7.2 & 8.4 Not Yet Installed; N/A See Sections 7.2 & 8.4 B-10 ID 2R44-S007 2T47-KGOO 2T47-K602 2T47-K603 2T47-K604 2T47-KGOS 2T47-N001J 2T47-N001K 2T47-N001M 2T47-N003 2T47-NODS 2T47-N007 MPR-4121 RevisionO Equipment Description 2SOVDC/120VAC FLEX Inverter 28 SIGNAL CONVERTER R/V N001J,K SIGNAL CONV R/V N001M, N003 SIG CONV R/V NODS, N007 SIG CONV R/V NOlO SIGNAL CONV R/V B009A Inlet Air TE-Div II DW CLG Dome Area TE-Div II B009A&B Inlet Air TE-Div II DW CLG Midlevel Area TE-Div II DW Lower Level Area TE-Div II DW Lower Level Area TE-Div II Operating State HCLPF Screening Notes/Comments Normal Desired Results Not Yet Installed; Energized Energized N/A See Sections 7.2 & 8.4 Operating Operating

!:RLGM Operating Operating

!:RLGM Inaccessible/High Operating Operating N/A Dose; See Section 7.1 Inaccessible/High Operating Operating N/A Dose; See Section 7.1 Inaccessible/High Operating Operating N/A Dose; See Section 7.1 Inaccessible/High Operating Operating N/A Dose; See Section 7.1 Inaccessible/High Operating Operating N/A Dose; See Section 7.1 Inaccessible/High Operating Operating N/A Dose; See Section 7.1 B-11 ID 2T47-NOlO 2T47-R627 2T48-AOOl 2T48-8002 2T48-F082 2T48-F318 2T48-F319 2T48-F320 2T48-F326 2T48-F408 2T48-F465 2T48-F468 2T48-K6088 MPR-4121 RevisionO Equipment Description Sacrificial Shield Top TE-Div II OW CLG CRD/Torus Area TR -Div II NITROGEN STORAGE TANK N2 TANKAM81ENT VAPORIZER HCVS Vent Control AOV HCVS Containment Isolation AOV HCVS Containment Isolation AOV HCVS Containment Isolation AOV HCVS Containment Isolation AOV Relief Valve Argon Supply Overpressure Protection 8002 DISCH LINE SRV 8002 DISCHARGE PCV (N2 system) OW Pressure lnst 1/V-Div II Operating State HCLPF Screening Notes/Comments Normal Desired Results Inaccessible/High Operating Operating N/A Dose; See Section 7.1 Operating Operating

?:RLGM Available Available

?:RLGM Repaired under Available Available

?:RLGM CAP andre-walked down; See Section 6.3.3. Closed Closed/Open

RLGM Closed Closed/Open

RLGM Closed Closed ::?:RLGM Closed Closed ::?:RLGM Closed Closed/Open

?:RLGM Not Yet Installed; Standby Standby N/A See Sections 7.2 & 8.4 Standby Standby :::: RLGM Operating Operating

?:RLGM Operating Operating

?:RLGM B-12 ID 2T48-K620B 2T48-K621B 2T48-K624B 2T48-N008B 2T48-N009B 2T48-N009D 2T48-N009E 2T48-N009H 2T48-N020B 2T48-N021B 2T48-N023B 2T48-R607B 2T48-R609 2T48-R631B 2T48-R632B MPR-4121 RevisionO Equipment Description DW/Torus Pressure lnst 1/V -Div II Torus Levellnst 1/V-Div II TORUS AIR TEMP R/V Torus Midrange PT-Div II Torus Water TE-Div II Torus Water TE-Div II Torus Air TE-Div II Torus Air TE-Div II DW Narrow Range PT-Div II Narrow Range Torus LT-Div II DW Midrange PT-Div II DW and Torus Narrow Range L/PR -Div II DW/Torus Midrange PR-Div II D/W MIDRANGE PI TORUS MIDRANGE PI Operating State HCLPF Screening Notes/Comments Normal Desired Results Operating Operating 2: RLGM Operating Operating 2: RLGM Operating Operating 2: RLGM Operating Operating 2: RLGM Operating Operating 2: RLGM Operating Operating 2: RLGM Operating Operating 2: RLGM Operating Operating 2: RLGM Operating Operating 2: RLGM Operating Operating 2: RLGM Operating Operating 2: RLGM Operating Operating 2: RLGM Operating Operating 2: RLGM Operating Operating 2: RLGM Operating Operating 2: RLGM B-13 ID 2X86-S003 2X86-S004 2Y52-AOOlA 2Y52-COOl A MPR-4121 RevisionO Equipment Description FLEX Connection Box 2A FLEX Connection Box 2B DG FUEL OIL STORAGE TANK 2A DIESEL 2A FUEL PUMP 2A1 Operating State HCLPF Screening Notes/Comments Normal Desired Results Not Yet Installed; Standby Standby N/A See Sections 7.2 & 8.4 Not Yet Installed; Standby Standby N/A See Sections 7.2 & 8.4 Available Available Available Available RLGM B-14 Edwin I. Hatch Nuclear Plant -Units 1 and 2 Expedited Seismic Evaluation Process Report -Fukushima Near-Term Task Force Recommendation

2.1 Enclosure

2 Required Actions and Schedule for Completion of ESEP Activities Enclosure 2 to NL-14-1989 Hatch Nuclear Plant-Units 1 and 2 Required Actions and Schedule for Completion of ESEP Activities Hatch Unit 1 Required Actions and Schedule for ESEL Items Not Installed as of Walkdowns/Report Issuance # Equipment Outage Required Scheduled Completion Number Required Action Date 1

1R26-M132 FLEX Fused Disconnect Switch 1A Does NOT require outage to After the item is installed, December 2016

1 R26-M 133 FLEX Fused Disconnect Switch 1 B walk down or install perform Seismic (2 years after ESEP Report modification (if modification is Walkdown, generate

1 R26-M 136 FLEX Transfer Switch 1 A necessary)

HCLPF evaluations in submittal)

1 R26-M 137 FLEX Transfer Switch 1 B accordance with EPRI

1 R26-M 139 FLEX Transfer Switch 1 D 3002000704 and EPRI

1 R26-M140 FLEX Transfer Switch 1 E NP-6041-SL, and design/

1T48-F408 Relief Argon Supply Overpressure implement any Protection modifications necessary to 1 X86-S003 600V FLEX Diesel Generator meet ESEP requirements.

(FLEX Connection Box 1 A)

1 X86-S004 600V FLEX Diesel Generator (FLEX Connection Box 1 B) 2

1 P52-A027A BKUP Air Accumulator Tank A Requires outage to walk down After the item is installed, Spring outage 2018

1 P52-A027B BKUP Air Accumulator Tank B or install modification (if perform Seismic (2 outages after December

1 P52-F1312 Relief Valve N2 Cylinder Supply modification is necessary)

Walkdown, generate 2014) HCLPF evaluations in Manifold Overpressure Protection accordance with EPRI

1 R25-S066 120VAC Critical instrument Cabinet 1 A 3002000704 and EPRI

1 R25-S067 120VAC Critical instrument Cabinet 1 B NP-6041-SL, and design/

1 R42-S026 Battery Charger 1 A -Div I implement any

1 R42-S027 Battery Charger 1 B -Div I modifications necessary to

1 R44-S006 250VDC/120VAC Inverter 1 A meet ESEP requirements.

1 R44-S007 250VDC/120VAC Inverter 1 B E2-1 Enclosure 2 to NL-14-1989 Hatch Nuclear Plant-Units 1 and 2 Required Actions and Schedule for Completion of ESEP Activities Hatch Unit 1 Required Actions and Schedule for ESEL Items Not Installed as of Walkdowns/Report Issuance # Equipment Outage Required Scheduled Completion Number Required Action Date 3 NA NA Submit letter to NRC 90 days following completion summarizing results of of ESEP activities, no later Unit 1 Items 1 and 2 and than 90 days after Spring 2018 provide confirmation that outage (if an outage is plant modifications required).

associations with Items 1 and 2 are complete.

Continued next page for Unit 2 E2-2 Enclosure 2 to NL-14-1989 Hatch Nuclear Plant-Units 1 and 2 Required Actions and Schedule for Completion of ESEP Activities Hatch Unit 2 Required Actions and Schedule for ESEL Items Not Installed as of Walkdowns/Report Issuance # Equipment Number Description Remaining Scope Completion Date 1

2R26-M126 FLEX Transfer Switch 2A Does NOT require outage to After the item is installed, December 2016

2R26-M 127 FLEX Transfer Switch 2B walk down or install perform Seismic Walkdown, (2 years after ESEP modification (if modification is generate HCLPF evaluations

2R26-M 129 FLEX Transfer Switch 2D necessary) in accordance with EPRI Report submittals)

2R26-M130 FLEX Transfer Switch 2E 3002000704 and EPRI NP-* 2R42-S026 Battery Charger 2A -Div I 6041-SL, and

2R42-S027 Battery Charger 2B -Div I design/implement any

2T 48-F408 Relief Argon Supply Overpressure necessary modifications Protection necessary to meet ESEP 2X86-S003 600V FLEX Diesel Generator requirements.

(FLEX Connection Box 2A)

2X86-S004 600V FLEX Diesel Generator (FLEX Connection Box 2B) 2

2P52-A027A BKUP Air Accumulator Tank A Requires outage to walk down After the item is installed, Spring outage 2017

2P52-A027B BKUP Air Accumulator Tank B or install modification (if perform Seismic Walkdown, (2 outages after December

2P52-F1228 Relief Valve N2 Cylinder Supply modification is necessary) generate HCLPF evaluations 2014) in accordance with EPRI Manifold Overpressure Protection 3002000704 and EPRI NP-* 2R25-S066 120VAC Critical instrument Cabinet 2A 6041-SL, and

2R25-S067 120VAC Critical instrument Cabinet 2B design/implement any

2R26-M 132 FLEX Fused Disconnect Switch 2A necessary modifications

2R26-M 133 FLEX Fused Disconnect Switch 2B necessary to meet ESEP 2R44-S006 250VDC/120VAC Inverter 2A requirements.

2R44-S007 250VDC/120VAC Inverter 2B E2-3 Enclosure 2 to NL-14-1989 Hatch Nuclear Plant-Units 1 and 2 Required Actions and Schedule for Completion of ESEP Activities Hatch Unit 2 Required Actions and Schedule for ESEL Items Not Installed as of Walkdowns/Report Issuance # Equipment Number Description Remaining Scope Completion Date 3 NA NA Submit letter to NRC 90 days following summarizing results of Unit 2 completion of ESEP Items 1 and 2 and provide activities, no later than 90 confirmation that plant days after Spring 2017 modifications associations with outage (if an outage is Items 1 and 2 are complete.

required).

E2-4 Edwin I. Hatch Nuclear Plant -Units 1 and 2 Expedited Seismic Evaluation Process Report -Fukushima Near-Term Task Force Recommendation

2.1 Enclosure

3 Table of Regulatory Commitments Enclosure 3 to NL-14-1989 Hatch Nuclear Plant -Units 1 and 2 Table of Regulatory Commitments Commitment Hatch Unit 1 Complete the remaining NTTF 2.1 Unit 1 ESEL walkdowns/evaluations for items that are not currently installed.

These items are identified in Attachment A of the Hatch Units 1 and 2 ESEP Report (Enclosure 1 of this letter) and summarized in Enclosure

2. Hatch Unit 2 Complete the remaining NTTF 2.1 Unit 2 ESEL walkdowns/evaluations for items that are not currently installed.

These items are identified in Attachment B of the Hatch Units 1 and 2 ESEP Report (Enclosure 1 of this letter) and summarized in Enclosure

2. Type Scheduled One-Time Continuing Completion Date Action Compliance (If Required)

X Within 90 days following completion of ESEP activities, no later than 90 days after Spring 2018 outage (if an outage is required).

X Within 90 days following completion of ESEP activities, no later than 90 days after Spring 2017 outage (if an outage is required).

E3-1

v t e Letter Sequence Other
TAC:MF5243, (Approved, Closed)
Initiation Acceptance... Administration Questions Answers Results Approval Other: ML15190A131, NL-14-1989, Expedited Seismic Evaluation Process Report - Fukushima Near-Term Task Force Recommendation 2.1
MONTHYEAR2015-07-22 [Table View]

NL-14-1989, Expedited Seismic Evaluation Process Report - Fukushima Near-Term Task Force Recommendation 2.1

Text

References:

Enclosures:

2.1 Enclosure

3.1 Equipment

6.3.1 Walkdown

6.4 HCLPF

3.1.4 Termination

3.1.5 Critical

3.1.6 Phase

5.1 DESCRIPTION

5.2 METHOD

SUMMARY

6.2 HCLPF

6.3.3 Significant

8.3 MODIFICATION

SUMMARY

2.1 Enclosure

2.1 Enclosure

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