ML19148A463

ABWR DC Renewal Issue 26 SER for Section 16 Technical Specifications Revision 3

ML19148A463
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Site:	05200045
Issue date:	06/19/2019
From:	James Shea NRC/NRO/DLSE
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Shea J
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ML19148A410	List: ML19148A461 ML19148A463
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16.0 Technical Specifications 16.1 Regulatory Criteria In the GE-Hitachi Nuclear Energy (GEH), Advanced Boiling-Water Reactor (ABWR) Design Control Document (DCD) Revision 6, GEH (the applicant) proposed design changes to improve the diversity and defense in depth of safety systems to enhance the ABWR coping capabilities during a beyond design-basis event and could provide a potential Combined License (COL) applicant the means for meeting the proposed Title 10 Code of Federal Regulations (10 CFR) 50.155, Mitigation of Beyond-Design Basis Events, rule.

This evaluation documents the staffs review of the applicants design enhancements and the proposed Technical Specification (TS) changes to demonstrate that the ABWR design meets the requirements of 10 CFR 50.34, Contents of applications; technical information, which states that proposed TSs are to be prepared in accordance with the requirements of 10 CFR 50.36, Technical specifications, which details the specific items (such as safety limits, limiting safety system settings, limiting control settings, limiting conditions for operation, etc.) that must be included in the TS.

In a letter dated July 20, 2012 (Agencywide Document and Access Management Systems (ADAMS) Accession No. ML12125A385), the U. S. Nuclear Regulatory Commission (NRC) staff identified 28 items for GEHs consideration as part of their application to renew the ABWR Design Certification (DC). The applicant was requested by the staff in Item No. 26, of the July 20, 2012, staff letter to address ABWR DCD design changes related to aspects of the NRC Fukushima Near Term Task Force (NTTF) Recommendation 4.2 regarding mitigation strategies for beyond-design-basis external events based on the NRC policy, at that time, which was outlined in a staff requirements memo 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 (ADAMS Accession No. ML12039A111).

In a letter dated January 23, 2017 (ADAMS Accession No. ML17025A386), GEH provided supplemental information for GEHs response to Item 26 of the NRC suggested ABWR design changes for consideration as part of their application to renew the ABWR DC. The applicant narrowed the scope of Item No. 26 to exclude changes directly related to SECY-12-0025, pending final rulemaking for the mitigation of beyond-design basis events (MBDBE) rule. As such, GEH retained related design changes that were proposed to address NTTF Recommendation 4.2 as well as the update to the ABWR TSs as an operational enhancement to provide additional defense in depth. These proposed ABWR design enhancements could provide a potential COL applicant the means for meeting the MBDBE rule requirements of 10 CFR 50.155.

These proposed changes do not fall within the definition of a modification. Therefore, in accordance with 10 CFR 52.59(c), these design changes are amendments, as this term is defined in Chapter 1 of this supplement and will correspondingly be evaluated using the regulations in effect at renewal. The applicable regulatory requirements for evaluating the proposed DCD TSs related to the proposed design amendments are as follows:

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• 10 CFR 52.47(a) - the applicant (GEH) must provide proposed TSs prepared in accordance with the requirements of 10 CFR 50.36 and 50.36a.

• 10 CFR 50.36 - TS impose limits, operating conditions, and other requirements upon reactor facility operation for the public health and safety. The TSs are derived from the analyses and evaluations in the safety analysis report. In general, a TS must contain:

(1) safety limits and limiting safety system settings; (2) limiting conditions for operation (3) surveillance requirements; (4) design features; and (5) administrative controls.

• 10 CFR 50.46, Acceptance criteria for emergency core cooling systems for light-water nuclear power reactors, - Acceptance Criteria for ECCS for light-water nuclear power reactors.

• 10 CFR Part 50, Domestic Licensing Of Production And Utilization Facilities, Appendix A, General Design Criteria (GDC) 33, Reactor Coolant Makeup, - A system to supply reactor coolant makeup for protection against small breaks in the reactor coolant pressure boundary shall be provided.

• 10 CFR Part 50, Appendix A, GDC 19, Control Room, - A control room shall be provided from which actions can be taken to operate the nuclear power unit safely under normal conditions and to maintain it in safe condition under accident conditions, including LOCA accidents. Adequate protection shall be provided to permit access and occupancy of the control room under accident conditions without personnel receiving radiation exposure in excess of 5 REM whole body, or its equivalent to any part of the body for the duration of the accident. Equipment at appropriate locations outside the control room shall be provided (1) with a design capability for prompt hot shutdown of the reactor, including necessary instrumentation and controls to maintain the unit in a safe condition during hot shutdown, and (2) with a potential capability for subsequent cold shutdown.

16.2 Summary of Technical Information Item 26 from the staff letter dated July 20, 2012, requested that the applicant 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 Commission Order EA-12-049 (ADAMS Accession No. ML12054A735), Issuance of Order to Modify Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events, issued on March 12, 2012.

Recent NRC actions involving a pending final rulemaking for the MBDBE rule, were discussed during a public teleconference held December 1, 2016. Under the latest public information regarding the pending final rule, there will be no requirements applicable to applicants for a standard DC (or a renewal, as in the case of the ABWR application). It is expected that the final rule will be effective before the ABWR DC renewal would be completed. On that basis, in a letter dated December 6, 2016, GEH informed the NRC of its plans to submit a revised response for addressing Item 26 by the end of January 2017. In its January 23, 2017, letter the applicant provided the updated GEH response for Item 26, maintaining some enhanced design features related to mitigating strategies that may be used by a potential COL applicant to satisfy the eventual MBDBE rule requirements including the proposed updates to the ABWR TSs.

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The proposed TS changes include: addition of Alternating Current (AC) Independent Water Addition (ACIWA) mode to Residual Heat Removal (RHR) Loop B (currently available for RHR Loop C), affecting TS 3.5.1, ECCS-Operating, and TS 3.6.2.4, RHR Containment Spray; and, additional controls and indications on 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:

1. Addition of Wide Range Reactor Pressure Vessel (RPV) Water Level indication (Division I & II) (Cold Calibration)

2. Addition of N2 Supply Header Pressure indication (Division I & II

3. Addition of Condensate Storage Tank (CST) Water Level indication (Division I)

4. Addition of Containment (Dry Well) Wide Range Pressure indication (Division I &

5. Addition of Wide Range Suppression Pool Water Level indication (Division I & II) 16.3 Technical Evaluation Changes to TS 3.5.1, ECCS-Operating (Add ACIWA mode to RHR Loop B (currently available for RHR Loop C):

GEH in its submittal dated January 23, 2017, state the following regarding changes to TS 3.5.1:

Diverse alternatives to RCIC are provided by the Combustion Turbine Generator (CTG) and the ACIWA mode of RHR. If RCIC is inoperable, water can be injected into the RPV either by powering other ECCS subsystems from the CTG or by the Fire Protection System (FPS) using one of the loops of the ACIWA mode of RHR (RHR C loop or RHR B loop which is added with DCD Revision 6).

With RCIC inoperable and one or two inoperable ECCS subsystem(s) inoperable (Conditions B and C) one of the loops (RHR loop B or RHR loop C) of the ACIWA mode of RHR is verified to be functional, so that the FPS can be used to inject water into the RPV during a station blackout with the RPV sufficiently depressurized. Loop B(C) of ACIWA is verified to be functional by stroking one complete cycle of each of the two manual valves in the FPS connection to the RHR Loop B(C) injection line, by starting the FPS diesel-driven fire pump and verifying that the FPS header pressure is maintained, and by stroking one complete cycle of the RHR Loop B(C) injection valve using its handwheel.

The staff reviewed these TS changes and concludes that they are acceptable because the changes reflect the design enhancements to the ECCS systems that provide additional capabilities and diversity in the case of a beyond design-basis event. Therefore, the staff concludes the changes meets the requirements of 10 CFR 52.47(a) and 10 CFR 50.36 and remains consistent with the staffs evaluation in the previous ABWR Final Safety Evaluation Report (FSER) NUREG-1503, Chapter 16, Technical Specifications.

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Changes to TS 3.6.2.4, RHR Containment Spray (Add ACIWA mode to RHR Loop B (currently available for RHR Loop C):

The primary containment is designed with a suppression pool so that, in the event of a loss of coolant accident (LOCA), or a rapid depressurization of the RPV through the safety/relief valves, steam released from the primary system is channeled through the suppression pool water and condensed without producing significant pressurization of the primary containment (without exceeding its design pressure). The primary containment must also withstand a postulated bypass leakage pathway that allows the passage of steam from the drywell directly into the wetwell airspace, bypassing the suppression pool. In that case, some means must be provided to condense steam from the wetwell so that the pressure inside primary containment remains within the design limit. This function is provided by two redundant RHR containment spray subsystems (only RHR subsystems B and C operate in this mode). The ACIWA mode of RHR provides a backup drywell or wetwell spray capability.

With one RHR containment spray subsystem inoperable, the ACIWA mode of RHR loop B or loop C, using the FPS, can be used to inject water into the drywell or wetwell spray spargers.

Loop B or loop C of ACIWA is verified to be functional by stroking one complete cycle of each of the two manual valves in the FPS connection to the RHR Loop B(C) injection line, by verifying that the FPS header pressure is maintained and by stroking one complete cycle of the RHR Loop B(C) injection valve.

The staff reviewed these TS changes and concludes that they are acceptable because the changes reflect the design enhancements to the RHR systems in the case of a beyond design-basis event. Therefore, the staff concludes the changes meet the requirements of 10 CFR 50.36 and remain consistent with the staffs evaluation in the previous ABWR FSER NUREG-1503, Chapter 16.

Changes to TS 3.3.6.2, Remote Shutdown Panel:

RPV Wide Range/Narrow Range Water Level (Addition of Wide Range RPV Water Level Indication - Cold Calibration) (Div. I & II) (TS Table 3.3.6.2-1, functions 12, 13, & 27) Reactor vessel water level is provided to support monitoring of core cooling, to verify operation of the make-up pumps, and is needed for satisfactory operator control of the make-up pumps. The wide range water level channels cover the range from the near top of the fuel to near the top of the steam separators. The narrow range provides indication from near the bottom of the separators to above the steam lines. RPV level is a necessary parameter for achieving and maintaining the reactor in MODE 3. There is an additional set of wide range instruments that have been calibrated for cold conditions and will be used when the normal instruments are off scale. One channel of each of the RPV Water Level conditions and ranges is provided on each of the RSS panels. Both channels are required to be OPERABLE to provide redundant capability to achieve MODE 3 from both RSS panels.

The staff reviewed these TS changes and concludes that they are acceptable because the changes reflect the design enhancements to the Remote Shutdown Panel in the case of a beyond design-basis event. Therefore, the staff concludes the changes meet the requirements of 10 CFR 52.47(a) and 10 CFR 50.36 and remain consistent with the staffs evaluation in the previous ABWR FSER NUREG-1503, Chapter 16.

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Suppression Pool Water Level, Narrow and Wide Range (Addition of Wide Range) (Div. I & II)

(TS Table 3.3.6.2-1, functions 18, & 26)

Suppression pool water level provides information needed to assess the status of the RCPB and to assess the status of the water supply to the ECCS. The narrow range level indicators monitor the suppression pool level from the bottom of the ECCS suction lines to five feet above the normal suppression pool level. The wide range level indicators monitor the suppression pool from the centerline of the ECCS suction piping to the wetwell spargers. One channel of both functions is provided on each of the RSS panels. Both channels are required to be OPERABLE to provide redundant capability to achieve MODE 3 from both RSS panels.

The staff reviewed these TS changes and concludes that they are acceptable because the changes reflect the design enhancements to Suppression Pool Water level in the case of a beyond design-basis event. Therefore, the staff concludes the changes meet the requirements of 10 CFR 52.47(a) and 10 CFR 50.36 and remain consistent with the staffs evaluation in the previous ABWR FSER NUREG-1503, Chapter 16.

Condensate Storage Tank Level (Addition of CST Water Level Indication Division I, which will be in addition to the existing Division II) (TS Table 3.3.6.2-1, functions 19)

Condensate Storage Tank Level provides information needed to assess the status of the water supply to reactor core isolation coolant (RCIC) and high-pressure core flooder (HPCF). The indication is needed in order to achieve and maintain MODE 3 when using RCIC and HPCF.

Both channels are required to be OPERABLE to achieve MODE 3 from both RSS panels.

The staff reviewed these TS changes and concludes that they are acceptable because the changes reflect the design enhancements to the CST Water Level Indication in the case of a beyond design-basis event. Therefore, the staff concludes the changes meet the requirements of 10 CFR 52.47(a) and 10 CFR 50.36 and remain consistent with the staffs evaluation in the previous ABWR FSER NUREG-1503, Chapter 16.

N2 Header Pressure (Addition of N2 Supply Header Pressure Indication) (Div. I & II) (TS Table 3.3.6.2-1, functions 24)

This Function is provided to permit monitoring the status of the N2 Bottle Header Pressure.

These monitors are required to permit the operator to manage the N2 supply to the SRVs. One channel of this Function is provided on each RSS panel. Both channels of the Function are required to be OPERABLE to provide redundant capacity to achieve MODE 3 from both RSS panels.

The staff reviewed these TS changes and concludes that they are acceptable because the changes reflect the design enhancements to N2 Supply Pressure Indications in the case of a beyond design-basis event. Therefore, the staff concludes the change meets the requirements of 10 CFR 52.47(a) and 10 CFR 50.36 and remain consistent with the staffs evaluation in the previous ABWR FSER NUREG-1503, Chapter 16, Technical Specifications.

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Drywell Pressure - Wide Range (Addition of Containment Wide Range Pressure Indication)

(Div. I & II) (TS Table 3.3.6.2-1, functions 25)

This function is provided to permit monitoring the status of the drywell pressure. This will allow the operator to determine if there is a potential of operation of Containment Overpressure Protection System (COPS). One channel of this Function is provided on each RSS panel. Both channels of the Function are required to be OPERABLE to provide redundant capacity RSS panels.

The staff reviewed these TS changes and concludes that they are acceptable because the changes reflect the design enhancements to the Containment drywell pressure indication in the case of a beyond design-basis event. Therefore, the staff concludes the changes meet the requirements of 10 CFR 52.47(a) and 10 CFR 50.36 and remain consistent with the staffs evaluation in the previous ABWR FSER NUREG-1503, Chapter 16.

16.4 Conclusion The staff reviewed the proposed GEH TS changes related to the ABWR design enhancements that were evaluated as DCD amendments as described in the GEH January 23, 2017 letter, Table 1. As described above, these additional controls and indications improve the diversity and defense in depth during beyond design basis events and enhance the safety of the plant. Therefore, the staff finds acceptable the above proposed changes made to align with the TS with the final safety analysis report changes and to be consistent with DCD Revision 6.

Therefore, the staff concludes the changes meet the requirements of 10 CFR 52.47(a) and 10 CFR 50.36 for all the associated TS changes and specifically meet requirements of 10 CFR 50.46, for the ECCS requirements, GDC 33 and GDC 19 requirements for light-water nuclear power reactors and remain consistent with the staffs evaluation in the previous ABWR FSER NUREG-1503, Chapter 16 and are therefore acceptable.

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