ML16120A032

GE-Hitachi Nuclear Energy Americas, LLC - Supplemental Information for Response to Item No. 26 - Fukushima Recommendation 4.2 Mitigation Strategies of NRC Suggested U.S. Advanced Boiling Water Reactor Design Changes

ML16120A032
Person / Time
Site:	05200045
Issue date:	04/29/2016
From:	Head J GE-Hitachi Nuclear Energy Americas
To:	Document Control Desk, Office of New Reactors
Shared Package
ML16120A031	List: ML16120A032 ML16120A033
References
MFN 15-069, Supplement 1
Download: ML16120A032 (13)

Text

GE Hitachi Nuclear Energy Jerald G. Head Senior Vice President, Regulatory Affairs 3901 Castle Hayne Road PO Box 780 M/C A-18 Wilmington, NC 28402-0780 USA T 910 819 5692 F 910 362 5692 jerald.head@ge.com MFN 15-069, Supplement 1 Docket number: 52-045 April 29, 2016 US Nuclear Regulatory Commission Document Control Desk Washington, DC 20555-0001

Subject:

Supplemental Information for GEHs Response to Item # 26 - Fukushima Recommendation 4.2 Mitigation Strategies of NRC Suggested U.S. Advanced Boiling Water Reactor Design Changes

References:

1. Letter from R.E. Kingston, GEH to USNRC,

Subject:

ABWR Standard Plant Design Certification Renewal Application Design Control Document, Revision 5, Tier 1 and Tier 2, December 7, 2010.

2. Letter from USNRC to Jerald G. Head, GEH,

Subject:

GE-Hitachi Nuclear Energy -

United States Advanced Boiling-Water Reactor Design Certification Renewal Application, July 20, 2012.

3. Letter from Jerald G. Head, GEH, to USNRC,

Subject:

Response to NRC Letter: GE Hitachi Nuclear Energy - United States Advanced Boiling-Water Reactor Design Certification Renewal Application (July 20, 2012), September 17, 2012.

4. Letter from Jerald G. Head, GEH, to USNRC,

Subject:

GEH Proposed Resolution of Item # 26 - Fukushima Recommendation 4.2 Mitigation Strategies of NRC Suggested U.S. Advanced Boiling Water Reactor Design Changes, September 4, 2015 GEH submitted a Design Certification Renewal application for the U.S. Advanced Boiling Water Reactor (ABWR) in Reference 1 pursuant to the requirements of Subpart B, Standard Design Certifications, of Title 10 of the Code of Federal Regulations (10 CFR) Part 52, Licenses, Certifications, and Approvals for Nuclear Power Plants.

In Reference 2, the NRC suggested design changes to address issues that the agency considered to be regulatory improvements or changes that could meet the 10 CFR 52.59(b)

MFN 15-069, Supplement 1 Page 2 of 3 criteria. In addition, the NRC requested that GEH implement the Fukushima Near-Term Task Force recommendations contained in SECY-12-0025, Proposed Orders and Requests for Information in Response to Lessons Learned from Japans March 11, 2011, Great Tohoku Earthquake and Tsunami, dated February 17, 2012. Collectively, these items are termed the 28-item backfit list.

In Reference 3, GEH responded to Reference 2 and committed to address the 28-item backfit list.

In public and private meetings the NRC held with GEH on May 7th, 2015, GEH reviewed the closure plan for the 28-item backfit list for those items that GEH would not receive any additional Requests for Additional Information. During that meeting, Item #26 of the 28-item backfit list was discussed and GEHs approach was revised taking into consideration the staffs feedback.

Reference 3 transmitted GEHs proposed resolution to Item #26 of the 28-item backfit list transmitted in Reference 2.

In a public teleconference with the NRC on March 17, 2016, the NRC Staff requested that GEH provide a clear picture of the ABWR response to a Beyond Design Basis Event (BDBE) with specific information items to be provided by the Combined Operating License (COL) Applicant. contains GEHs proposed resolution transmitted in Reference 4 and the NRC Staff requested supplemental information. Enclosure 2 contains the Design Control Document markups associated with just GEHs supplemental information response.

If you have any questions concerning this letter, please contact Hugh Upton at 408-314-8499.

I declare under penalty of perjury that the foregoing information is true and correct to the best of my knowledge, information, and belief.

Sincerely, Jerald G. Head Senior Vice President, Regulatory Affairs Commitments: No additional commitments are made in this response.

Enclosures:

1. GEH Proposed Resolution and Response to NRCs Request for Supplemental Information to Item #26 - Fukushima Recommendation 4.2 - Mitigation Strategies

2. GEHs Response to NRCs Request for Supplemental Information to Item #26 - Fukushima Recommendation 4.2 - Mitigation Strategies - ABWR DCD Revision 6 Markups

MFN 15-069, Supplement 1 Page 3 of 3 cc: Adrian Muniz, NRC David Sledzik, GEH Peter Yandow, GEH Patricia Campbell, GEH Douglas McDonald, GEH Hugh A. Upton, GEH James A. Beard, GEH Erik Kirstein, GEH Julie Leong, GEH Bruce Rudd, GEH DBR - 0012411

Enclosure 1 MFN 15-069, Supplement 1 GEH Proposed Resolution and Response to NRCs Request for Supplemental Information to Item #26 - Fukushima Recommendation 4.2 - Mitigation Strategies IMPORTANT NOTICE REGARDING CONTENTS OF THIS DOCUMENT Please Read Carefully The information contained in this document is furnished solely for the purpose(s) stated in the transmittal letter. The only undertakings of GEH with respect to information in this document are contained in the contracts between GEH and its customers or participating utilities, and nothing contained in this document shall be construed as changing that contract. The use of this information by anyone for any purpose other than that for which it is intended is not authorized; and with respect to any unauthorized use, GEH makes no representation or warranty, and assumes no liability as to the completeness, accuracy, or usefulness of the information contained in this document.

MFN 15-069, Supplement 1 Page 1 of 9 (Below, for convenience, is GEHs Proposed Resolution of Item # 26 - Fukushima Recommendation 4.2 Mitigation Strategies provided in MFN 15-069 transmitted September 4, 2015. For DCD Revision 5 markups described below, see the MFN 15-069 enclosure.)

NRC - Fukushima Recommendation 4.2 - Mitigation Strategies Address the design related aspects of Fukushima Recommendation 4.2 regarding mitigation strategies for beyond-design-basis external events as outlined in Attachment 2 of the Order issued on March 12, 2012 (ML12054A735).

GEH Response:

To provide plant operators with additional mitigation options for response to a Beyond Design Basis Event, GEH will make the following modifications:

• Add Alternating Current (AC) Independent Water Addition (ACIWA) subsystem to Residual Heat Removal (RHR) Loop B, including connection to the Fire Protection system (FP) and external hose connection for fire truck.

• Make FP diesel-driven fire pump fuel capacity sufficient for 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> of operation; include severe weather/flooding protection for ACIWA and the diesel-driven fire pump.

• Analyze Reactor Core Isolation Cooling (RCIC) system for operation with 121°C (250°F) pump suction temperature.

• Add Reactor Building (RB) external connections for Diverse and Flexible Coping Strategies (FLEX) diesel generators to 480VAC RB 1E power centers.

Summary To address core cooling, spent fuel pool (SFP) makeup, and containment spray, GEH will amend the ABWR DCD, Tier 1, Section 2.4.1 and Tier 2, Table 1AA-2, Table 3.2-1, Table 3.9-8, MA.2, Section 5.4, Technical Specifications (TS) Limiting Conditions for Operation (LCOs) 3.5.1 and 3.6.2.4 Actions/Bases, and Section 19.9 to include the addition of ACIWA capability to Loop B of RHR. Tier 1, Section 2.15.6 will be amended to include wetwell spray and SFP makeup in the firewater supply to RHR description. Tier 1, Section 2.4.4 and Tier 2, Section 5.4 will also be amended to show analysis of RCIC operation at 121°C SP temperature during beyond design basis events. Tier 2, Section 19.8 will be amended to include severe weather and flooding protection, minimum fuel supply requirement for ACIWA and the diesel-driven fire pump. Tier 2, Sections 19.8 and 19.9 will be amended to include wetwell spray and spent fuel pool makeup in the ACIWA description.

GEH will amend ABWR DCD, Tier 1, Section 2.12.1 and Tier 2, Section 8.3 to describe the addition of external connection points for FLEX portable 480 VAC diesel generator(s).

Impact on the DCD ABWR DCD rev 5, Tier 1, Section 2.4.1, third paragraph will be changed to read:

Except for the non-ASME Code components of the alternating current (AC) power source independent water addition feature (Figures 2.4.1b and 2.4.1c), the entire RHR System shown on Figures 2.4.1a, 2.4.1b, and 2.4.1c is classified as safety-related.

MFN 15-069, Supplement 1 Page 2 of 9 ABWR DCD rev 5, Tier 1, Section 2.4.1 RHR operating modes list item (7) will be changed to read:

(7) AC power source independent water addition (Divisions B and C)

ABWR DCD rev 5, Tier 1, Section 2.4.1 AC Independent Water Addition Mode will be changed to read:

Divisions B and C of the RHR System will also function in an AC independent water addition mode. This mode provides a means of injecting emergency makeup water to the reactor by cross connecting the Reactor Building Fire Protection (FP) System header, or alternately utilizing additional sources of water from external connections just outside the Reactor Building. This makes the mode independent of the normal safety-related AC power distribution network. This mode is accomplished by manually opening two in-series valves on the cross-connection piping just upstream of the tie-in to the normal RHR piping. This is accomplished by local manual action at the valves.

Fire Protection System water can be directed to either the RPV, the wetwell or drywell spray sparger, or the spent fuel pool by local manual opening of the Division B or C RHR injection valve, the Division B or C wetwell spray valve, the two Division B or C drywell spray valves, or the two Division B or C valves to the Fuel Pool Cooling and Cleanup System (FPC), respectively. Local manual as used in this paragraph means manually operating the valves at the valves.

ABWR DCD rev 5, Tier 1, Section 2.4.1 Other Provisions, last sentence of last paragraph will be changed to read:

For RHR-B and C, the upgraded branch lines include all the paths listed for RHR-A plus the supplemental fuel pool cooling suction path from the Fuel Pool Cooling System (including the RHR isolation valve) that connects to the shutdown cooling suction line, titled From FPC. The upgraded lines also include the pipelines and valves that are part of the AC independent water addition mode that extend from the non-code boundary indicated by NNS to the external connection outside the reactor building and to the Fire Protection System interfaces indicated by FP.

ABWR DCD rev 5, Tier 1, Figure 2.4.1.b Residual Heat Removal System (RHR-B) will be updated to show the new AC independent water addition piping, valves, and connections for Loop B.

To ABWR DCD rev 5, Tier 1, Section 2.4.4, the following text will be added:

The RCIC system is capable of injecting sufficient water to the vessel to maintain core cooling with suction aligned to the suppression pool and a suction temperature of 121°C (250°F) during beyond design basis events (e.g. Extended Station Blackout).

MFN 15-069, Supplement 1 Page 3 of 9 To ABWR DCD rev 5, Tier 1, Section 2.4.4, Table 2.4.4 the following text will be added:

Design Commitment Inspections, Tests, Analyses Acceptance Criteria

11. The RCIC system has the 11. Analyses will be 11. The RCIC system is capability of injecting performed of the as-built capable of injecting sufficient water to the RCIC System to assess sufficient water to the vessel to maintain core the system capability with vessel to maintain core cooling with suction 121°C water at the pump cooling with suction aligned to the suppression suction. aligned to the suppression pool and a suction pool and a suction temperature of 121°C temperature of 121°C (250°F) during beyond (250°F) during beyond design basis events (e.g. design basis events (e.g.

Extended Station Extended Station Blackout). Blackout).

ABWR DCD rev 5, Tier 1, Section 2.15.6 will be modified to read:

Fire water supply connections to Loops B and C of the Residual Heat Removal System piping are provided from the portion of FPS used for the Reactor and Control Buildings.

These connections are part of the AC independent water addition mode of the RHR System for reactor vessel injection, wetwell or drywell spray, or spent fuel pool makeup.

ABWR DCD rev 5, Tier 2, Table 1AA-2, page 1AA-11 will be modified to read:

FPS Supply Valve E11-F101, 102, 103;B,C Valve Rm. B,C (SC)

ABWR DCD rev 5, Tier 2, Table 3.2-1, E11 RHR System will be modified to read:

11. Valves to fire protection, Subsystems B and C (F100B/C, F103B/C and F104B/C)

ABWR DCD rev 5, Tier 2, Table 3.9-8, page 3.9-105 will be modified as follows:

E11-F101 and E11-F102 Qty will be changed to 2.

Figure 5.4-10 sh. 5 will be added to Tier 2 Fig. column for E11-F101 and E11-F102.

ABWR DCD rev 5, Tier 2, Attachment 3MA.2.2 will be modified to reflect the addition of ACIWA to RHR Loop B.

ABWR DCD rev 5, Tier 2, Attachment 3MA.2.3 will be modified to move the RHR Subsystem C suction piping from the suppression pool from the middle of RHR B section to the beginning of the RHR C section and to add the new RHR Subsystem B outdoor fire truck connection in RHR pump discharge pipe to the RPV to the end of the RHR B section.

MFN 15-069, Supplement 1 Page 4 of 9 ABWR DCD rev 5, Tier 2, Section 5.4.6.1.1.1 will be modified to read:

The RCIC System shall initiate and discharge, within 30 seconds, a specified constant flow into the reactor vessel over a specified pressure range. The RCIC water discharge into the reactor vessel varies between a temperature of 10°C up to and including a temperature of 77°C during design conditions and up to 121°C during beyond design basis events (e.g.

Extended Station Blackout). The mixture of the cool RCIC water and the hot steam does the following:

ABWR DCD rev 5, Tier 2, Section 5.4.7.1 will be modified to read:

The RHR System has two AC-independent water addition subsystems which consist of piping and manual valves connecting the fire protection system to the RHR pump discharge lines on loops B and C downstream of each main pump's discharge check valve. These flow paths allow for injection of water into the reactor vessel, wetwell or drywell spray, or the spent fuel pool during severe accident conditions in which all AC power and all ECCS pumps are unavailable. Additionally, hookups are provided external to the reactor building for connection of a fire truck pump and alternate water source to each subsystem. The hookups are on different faces of the reactor building and separated by more than 40 meters.

ABWR DCD rev 5, Tier 2, Section 5.4.7.1.1.10 will be modified to read:

The AC-independent water addition mode (Alternating Current independent) of the RHR System provides a means for introducing water from the Fire Protection System (FPS) directly into the reactor pressure vessel, to the drywell or wetwell spray header, or to the spent fuel pool under degraded plant conditions when AC power is not available from either onsite or offsite sources. The RHR System provides the piping and valves which connect the FPS piping with RHR loops B and C pump discharge piping. The manual valves in these lines permit adding water from the FPS to the RHR System if the RHR System is not operable. The primary means for supplying water through this connection is by use of the diesel-driven pump in the FPS. A backup to this pump is provided by connections on the outside of the reactor building at grade level, which allows hookup of the ACIWA to fire truck pumps.

Figure 5.4-10 shows the connections from either the diesel-driven pump or the fire truck to RHR system loops B and C. The connections to the diesel-driven pump (FPS) are adjacent to the RHR valve rooms. Opening valves F101B/C and F102B/C allows water to flow from the FPS into the RHR piping. Periodic stroke testing of these valves is required by Table 3.9-8 to ensure valve operability. The fire truck connections are located outside the reactor building at grade level, on different faces of the building. Both connections to the RHR system are protected by a check valve (F100B/C and F104B/C for the diesel-driven pump and the fire truck, respectively) to insure that RCS pressurization does not result in a breach of the injection path. Detailed procedures for the operation of the ACIWA, including operation of the FPS valve in the yard, are required to be developed by the COL applicant. See Section 19.9.7.

MFN 15-069, Supplement 1 Page 5 of 9 ABWR DCD rev 5, Tier 2, Section 5.4.7.1.1.10.4 will be modified to read:

Operation of the AC-independent water addition mode is entirely manual. All of the valves which must be opened or closed during fire water addition are located adjacent to or within the applicable ECCS valve room. The connections to add water using fire truck pumps are located outside the reactor building at grade level on different faces of the building.

ABWR DCD rev 5, Tier 2, Section 5.4.7.2.6(8) will be modified to read:

The RHR System is provided with piping and valves which separately connect RHR loops B and C pump discharge piping to the Fire Protection System (FPS) and to reactor building external fire truck pump hookups. These connections allow for addition of FPS water to the reactor pressure vessel, the drywell or wetwell spray header, or the spent fuel pool during events when AC power is unavailable from both onsite and offsite sources.

Operation of the RHR System in the AC-independent water addition mode is entirely manual. All valves required to be opened or closed for operation are located adjacent to or within the respective loop ECCS valve room to provide ease of operation.

ABWR DCD rev 5, Tier 2, Table 5.4-2 will be modified to account for analysis of RCIC system operation at 121°C SP temperature during beyond design basis events (e.g. Extended Station Blackout). This appears in two places in the table.

ABWR DCD rev 5, Tier 2, Figure 5.4-10 Residual Heat Removal System P&ID (Sheet 5 of 7) will be updated to show the new AC independent water addition piping, valves, and connections for Loop B.

ABWR DCD rev 5, Tier 2, Figure 5.4-10 Residual Heat Removal System P&ID (Sheet 7 of 7) will be updated to show the naming changes for ACIWA valves and instruments for Loop C.

ABWR DCD rev 5, Tier 2, Chapter 16 Technical Specification LCOs 3.5.1 and 3.6.2.4 Actions will be updated to reflect the addition of ACIWA to RHR Loop B.

ABWR DCD rev 5, Tier 2, Chapter 16 Technical Specification LCOs 3.5.1 and 3.6.2.4 Bases will be updated to reflect the addition of ACIWA to RHR Loop B.

To ABWR DCD rev 5, Tier 2, Section 19.8.1.3 the following text will be added:

The ACIWA System (including the diesel-driven fire pump fuel supply tank) will be protected against site flood and severe weather events. The ACIWA diesel fuel storage tank will have sufficient storage capacity to support 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> of operation.

ABWR DCD rev 5, Tier 2, Section 19.8.2.3 will be updated to include wetwell spray and spent fuel pool makeup in the ACIWA description.

ABWR DCD rev 5, Tier 2, Table 19.8-2 Seismic qualification of the ACIWA system Basis will be updated to include wetwell spray and spent fuel pool.

ABWR DCD rev 5, Tier 2 ,Table 19.8-7 Firewater Addition System Injection Locations will be updated to include wetwell spray and spent fuel pool.

ABWR DCD rev 5, Tier 2, Section 19.9.7 will be amended to include spent fuel pool makeup.

MFN 15-069, Supplement 1 Page 6 of 9 ABWR DCD rev 5, Tier 2, Section 19.9.7 will be amended to read:

The procedures to be developed by the applicant will address operation of the ACIWA for vessel injection, drywell or wetwell spray operation, and spent fuel pool makeup. Operation of the ACIWA System in the vessel injection mode requires valves F005B/C, F101B/C, and F102B/C to be opened and valve F592B/C to be closed. Reactor depressurization to below ACIWA System operating pressure is required prior to ACIWA operation in the vessel injection mode. Operation of the ACIWA in the drywell spray mode requires valves F017B/C, F018B/C, F101B/C, and F102B/C to be opened and valve F592B/C to be closed. Operation of the ACIWA in the wetwell spray mode requires valves F019B/C, F101B/C, and F102B/C to be opened and valve F592B/C to be closed. Operation of the ACIWA in the spent fuel pool makeup mode requires valves F014B/C, F015B/C, F101B/C, and F102B/C to be opened and valve F592B/C to be closed. These valves are shown on Figure 5.4-10. The diesel fire pump will start automatically when the ACIWA is properly aligned. If the normal firewater system water supply is unavailable, the alternate water supply can be made available by opening the manual valve between the diesel driven fire pump and the alternate water supply. This valve is shown in Figure 9.5-4. If it is necessary to use a fire truck, valve F103B/C must be opened in addition to operation of the valves discussed above for ACIWA operation. The valve for operation of the ACIWA using the fire truck is also shown on Figure 5.4-10. All of the valves required for ACIWA operation are manually operable.

To ABWR DCD rev 5, Tier 1, Section 2.12.1, the following text will be added:

External (to Reactor Building) connections are provided to all three 1E Reactor Building 480 VAC Power Centers for portable FLEX diesel generators. The connectors are isolated from the Power Centers by normally open 1E breakers.

ABWR DCD rev 5, Tier 1, Figure 2.12.1 will be updated to show the FLEX diesel generator tie-in points to the 1E divisional power centers.

To ABWR DCD rev 5, Tier 2, Section 8.3.1.1.2.1, the following text will be added:

To deal with an Extended Loss of AC Power (ELAP), external (to the Reactor Building) connections to each 1E RB divisional power center for portable FLEX 480 VAC diesel generators (DG) are installed, normally isolated from the 1E 480 VAC divisional Power Centers by open 1E breakers. The Reactor and Control Building 480 VAC buses can be re-energized via FLEX DGs, powering the 1E battery chargers, DC buses, and vital buses through UPS. The 480 VAC bus feeder breaker from the 6.9 KV to 480 V transformer and all load breakers on the Power Center will be opened to isolate the bus. The FLEX DG is connected, started, then the bus feeder from the DG is closed, energizing the 480 VAC power center. Power center load breakers are then closed one by one to energize loads (MCCs and discrete loads).

ABWR DCD rev 5, Tier 2, Figure 8.3-1 Sheet 3 will be updated to show the FLEX diesel generator tie-in points to the 1E divisional power centers.

The ABWR DCD Rev 5 marked-up pages are provided in Enclosure 2 (of MFN 15-069 transmitted September 4, 2015). Pages from the beginning of the DCD section have been included even though they may not have changed to provide easier review.

MFN 15-069, Supplement 1 Page 7 of 9 NRC Request for Supplemental Information:

In a public teleconference with the NRC on March 17, 2016, the NRC Staff requested that GEH provide a clear picture of the ABWR response to a Beyond Design Basis Event (BDBE) with specific information items to be provided by the Combined Operating License (COL) Applicant.

GEH Response to Supplemental Information Request:

In order to consolidate and organize ABWR design features and identify information to be provided by the COL Applicant, GEH has prepared a new Appendix (Appendix 1D, Response to NRC Post-Fukushima Recommendations) to be added to Chapter 1 of the ABWR DCD. This appendix addresses SECY-12-0025 Tier 1 recommendations (recommendations which the staff determined should be started without unnecessary delay) and Orders contained in, SECY-11-0137 Tier 2 recommendations (recommendations which could not be initiated in the near term) and the modifications documented in the Staff Requirements Memorandum (SRM) for SECY-12-0025 consistent with the as issued orders EA-12-049, EA-12-050 and EA-12-051. ABWR DCD Appendix 1D is in the same format as the South Texas Project 3&4 COLA to provide consistency with subsequent COL Applications.

During preparation of Appendix 1D, it was determined that additional controls and indications (utilizing design detail from Lungmen) could be provided for the ABWR Remote Shutdown Panel. These additional controls and indications improve the diversity and defense in depth during beyond design basis events. These changes to the Remote Shutdown Panel include:

• Replacement of control for SRVs G, J, K, and P with Control for ADS SRVs C, H, L and R

• Addition of Wide Range RPV Water Level indication (Division I and II) (Cold Calibration)

• Addition of N2 Supply Header Pressure indication (Division I and II)

• Addition of CST Water Level indication (Division I in addition to the existing Division II indication)

• Addition of Containment Wide Range Pressure indication (Division I and II)

• Addition of Wide Range Suppression Pool Water Level indication (Division I and II)

Impact on DCD of GEH Response:

Appendix 1D is added to ABWR DCD Tier 2, Chapter 1 Rev. 6. This new Appendix is provided in Enclosure 2.

The following ABWR DCD Revision 6 subsections, tables, and figures are revised as shown in the markups provided in Enclosure 2 as a result of this response:

MFN 15-069, Supplement 1 Page 8 of 9

• ABWR DCD Tier 1 Figure 2.1.2a

• ABWR DCD Tier 1 Figure 2.1.2e

• ABWR DCD Tier 1 Section 2.2.6

• ABWR DCD Tier 1 Figure 2.2.6

• ABWR DCD Tier 1 Figure 2.11.2

• ABWR DCD Tier 1 Section 2.11.13

• ABWR DCD Tier 2 Section 7.4.1.4.4 (4, 9, 10 & 13)

• ABWR DCD Tier 2 Section 16.3.3.6.2

• ABWR DCD Tier 2 Section 16.B.3.3.6.2

• ABWR DCD Tier 2 Chapter 21 Figure 5.1-3, Sheet 2

• ABWR DCD Tier 2 Chapter 21 Figure 5.1-3, Sheet 5

• ABWR DCD Tier 2 Chapter 21 Figure 5.1-3, Sheet 6

• ABWR DCD Tier 2 Chapter 21 Figure 6.2-39, Sheet 2

• ABWR DCD Tier 2 Chapter 21 Figure 6.2-39, Sheet 3

• ABWR DCD Tier 2 Chapter 21 Figure 6.7-1

• ABWR DCD Tier 2 Chapter 21 Figure 7.3-2, Sheet 2

• ABWR DCD Tier 2 Chapter 21 Figure 7.3-2, Sheet 3

• ABWR DCD Tier 2 Chapter 21 Figure 7.3-2, Sheet 4

• ABWR DCD Tier 2 Chapter 21 Figure 7.3-2, Sheet 6

• ABWR DCD Tier 2 Chapter 21 Figure 7.3-2, Sheet 7

• ABWR DCD Tier 2 Chapter 21 Figure 7.3-2, Sheet 9

• ABWR DCD Tier 2 Chapter 21 Figure 7.3-2, Sheet 10

• ABWR DCD Tier 2 Chapter 21 Figure 7.3-2, Sheet 18

• ABWR DCD Tier 2 Chapter 21 Figure 7.4-2

• ABWR DCD Tier 2 Chapter 21 Figure 7.4-3, Sheet 2

• ABWR DCD Tier 2 Chapter 21 Figure 7.4-3, Sheet 9

• ABWR DCD Tier 2 Chapter 21 Figure 9.2-4

Enclosure 2 MFN 15-069, Supplement 1 GEHs Response to NRCs Request for Supplemental Information to Item #26 - Fukushima Recommendation 4.2 -

Mitigation Strategies ABWR DCD Revision 6 Markups IMPORTANT NOTICE REGARDING CONTENTS OF THIS DOCUMENT Please Read Carefully The information contained in this document is furnished solely for the purpose(s) stated in the transmittal letter. The only undertakings of GEH with respect to information in this document are contained in the contracts between GEH and its customers or participating utilities, and nothing contained in this document shall be construed as changing that contract. The use of this information by anyone for any purpose other than that for which it is intended is not authorized; and with respect to any unauthorized use, GEH makes no representation or warranty, and assumes no liability as to the completeness, accuracy, or usefulness of the information contained in this document.