RS-17-065, Sixth Six-Month Status Report for Phases 1 and 2 Overall Integrated Plan in Response to June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation ..

Sixth Six-Month Status Report for Phases 1 and 2 Overall Integrated Plan in Response to June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation ..

ML17180A391
Person / Time
Site:	LaSalle
Issue date:	06/29/2017
From:	Gullott D Exelon Generation Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
EA-13-109, RS-17-065
Download: ML17180A391 (23)

Text

.A`'"

Exelon Generation(,,',

Order No. EA-13-109 RS-17-065 June 29, 2017 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 LaSalle County Station, Units 1 and 2 Renewed Facility Operating License Nos. NPF-11 and NPF-18 NRC Docket Nos. 50-373 and 50-374

Subject:

Sixth Six-Month Status Report For Phases 1 and 2 Overall Integrated Plan in Response to June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number EA-13-109)

References:

1. NRC Order Number EA-13-109, "Issuance of Order to Modify Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions," dated June 6, 2013

2. NRC Interim Staff Guidance JLD-ISG-2013-02, "Compliance with Order EA-13-109, Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation under Severe Accident Conditions", Revision 0, dated November 14, 2013

3. NRC Interim Staff Guidance JLD-ISG-2015-01, "Compliance with Phase 2 Order EA-13-109, Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation under Severe Accident Conditions", Revision 0, dated April 2015

4. NEI 13-02, "Industry Guidance for Compliance With Order EA-13-109, BWR Mark I & II Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions", Revision 1, dated April 2015

5. Exelon Generation Company, LLC's Answer to June 6, 2013, Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number EA-13-109), dated June 26, 2013

6. Exelon Generation Company, LLC Phase 1 Overall Integrated Plan in Response to June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number EA-13-109), dated June 30, 2014 (RS-14-059)

7. Exelon Generation Company, LLC First Six-Month Status Report Phase 1 Overall Integrated Plan in Response to June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number EA-13-109), dated December 17, 2014 (RS-14-303)

8. Exelon Generation Company, LLC Second Six-Month Status Report Phase 1 Overall Integrated Plan in Response to June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number EA-13-109), dated June 30, 2015 (RS-15-149)

U.S. Nuclear Regulatory Commission Integrated Plan Report to EA-13-109 June 29, 2017 Page 2

9. Exelon Generation Company, LLC Phase 1 (Updated) and Phase 2 Overall Integrated Plan in Response to June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number EA-13-109), dated December 16, 2015 (RS-15-300)

10. Exelon Generation Company, LLC Fourth Six-Month Status Report For Phases 1 and 2 Overall Integrated Plan in Response to June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number EA-13-109), dated June 30, 2016 (RS-16-107)

11. Exelon Generation Company, LLC Fifth Six-Month Status Report For Phases 1 and 2 Overall Integrated Plan in Response to June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number EA-13-109), dated December 14, 2016 (RS-16-233)

12. NRC letter to Exelon Generation Company, LLC, LaSalle County Station, Units 1 and 2 Interim Staff Evaluation Relating to Overall Integrated Plan in Response to Phase 1 of Order EA-13-109 (Severe Accident Capable Hardened Vents) (TAC Nos. MF4456 and MF4457), dated March 31, 2015

13. NRC letter to Exelon Generation Company, LLC, LaSalle County Station, Units 1 and 2 Interim Staff Evaluation Relating to Overall Integrated Plan in Response to Phase 2 of Order EA-13-109 (Severe Accident Capable Hardened Vents) (TAC Nos. MF4456 and MF4457), dated August 2, 2016 On June 6, 2013, the Nuclear Regulatory Commission ("NRC" or "Commission") issued an Order (Reference 1) to Exelon Generation Company, LLC (EGC). Reference 1 was immediately effective and directs EGC to require their BWRs with Mark I and Mark II containments to take certain actions to ensure that these facilities have a hardened containment vent system (HCVS) to remove decay heat from the containment, and maintain control of containment pressure within acceptable limits following events that result in loss of active containment heat removal capability while maintaining the capability to operate under severe accident (SA) conditions resulting from an Extended Loss of AC Power (ELAP). Specific requirements are outlined in Attachment 2 of Reference 1.

Reference 1 required submission of an Overall Integrated Plan (OIP) by June 30, 2014 for Phase 1 of the Order, and an OIP by December 31, 2015 for Phase 2 of the Order. The interim staff guidance (References 2 and 3) provide direction regarding the content of the OIP for Phase 1 and Phase 2. Reference 3 endorses industry guidance document NEI 13-02, Revision 1 (Reference 4) with clarifications and exceptions identified in References 2 and 3. Reference 5 provided the EGC initial response regarding reliable hardened containment vents capable of operation under severe accident conditions. Reference 6 provided the LaSalle County Station, Units 1 and 2, Phase 1 OIP pursuant to Section IV, Condition D.1 of Reference 1. References 7 and 8 provided the first and second six-month status reports pursuant to Section IV, Condition D.3 of Reference 1 for LaSalle County Station. Reference 9 provided the LaSalle County Station, Units 1 and 2, Phase 1 updated and Phase 2 OIP pursuant to Section IV, Conditions D.2 and D.3 of Reference 1. References 10 and 11 provided the fourth and fifth six-month status reports pursuant to Section IV, Condition D.3 of Reference 1 for LaSalle County Station.

U.S. Nuclear Regulatory Commission Integrated Plan Report to EA-13-109 June 29, 2017 Page 3 The purpose of this letter is to provide the sixth six-month update report for Phases 1 and 2, pursuant to Section IV, Condition D.3 of Reference 1, that delineates progress made in implementing the requirements of Reference 1 for LaSalle County Station, Units 1 and 2. The enclosed report provides an update of milestone accomplishments since the last status report, including any changes to the compliance method, schedule, or need for relief and the basis, if any. The enclosed report also addresses the NRC Interim Staff Evaluation open items contained in References 12 and 13.

This letter contains no new regulatory commitments. If you have any questions regarding this report, please contact David J. Distel at 610-765-5517.

declare under penalty of perjury that the foregoing is true and correct. Executed on the 29th day of June 2017.

Respectfully submitted, avid M. Gullott Manager - Licensing Exelon Generation Company, LLC

Enclosure:

LaSalle County Station, Units 1 and 2 Sixth Six-Month Status Report for Phases 1 and 2 Implementation of Order EA-13-109, Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions cc: Director, Office of Nuclear Reactor Regulation NRC Regional Administrator - Region III NRC Senior Resident Inspector - LaSalle County Station NRC Project Manager, NRR - LaSalle County Station Mr. Raj Auluck, NRR/JLD/TSD/JCBB, NRC Mr. Brian E. Lee, NRR/JLD/JCBB, NRC Mr. John P. Boska, NRR/JLD/JOMB, NRC Illinois Emergency Management Agency - Division of Nuclear Safety

Enclosure LaSalle County Station, Units 1 and 2 Sixth Six-Month Status Report for Phases 1 and 2 Implementation of Order EA-13-109, Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (19 pages)

COMBINED PHASES 1 AND 2 SIX MONTH UPDATE Enclosure LaSalle's Sixth Six Month Status Report for the Implementation of Order EA-13-109, "Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation under Severe Accident Conditions" 1 Introduction LaSalle developed an Overall Integrated Plan (Reference 1), documenting the installation of a Hardened Containment Vent System (RCVS) that provides a reliable hardened venting capability for pre-core damage and under severe accident conditions, including those involving a breach of the reactor vessel by molten core debris, in response to NRC Order EA-13-109 (Reference 2). Updates of milestone accomplishments are based on the combined Phases 1 and 2 Overall Integrated Plan (Reference 7), documenting:

The installation of a Hardened Containment Vent System (HCVS) that provides a reliable hardened venting capability for pre-core damage and under severe accident conditions, including those involving a breach of the reactor vessel by molten core debris, in response to Reference 2.

2. An alternative venting strategy that makes it unlikely that a drywell vent is needed to protect the containment from overpressure related failure under severe accident conditions, including those that involve a breach of the reactor vessel by molten core debris, in response to Reference 2.

This enclosure provides an update of milestone accomplishments since submittal of the latest status report, including any changes to the compliance method, schedule, or need for relief/relaxation and the basis, if any.

The following milestone(s) have been completed since November 11, 2016, and are current as of June 1, 2017:

• Sixth Six-Month Update (complete with this submittal)

• Phase 1 Unit 2 HCVS Implementation

• Phase 1 Unit 1 Begin Online Installation

• Phase 2 Unit 1 Begin Detailed Design 3 Milestone Schedule Status The following provides an update to Attachment 2 of the combined Phases 1 and 2 Overall Integrated Plan. It provides the activity status of each item, and whether the expected completion date has changed. The dates are planning dates subject to change as design and implementation details are developed.

Page 1 of 19

The revised milestone target completion dates do not impact the order implementation date.

Target Activity Milestone Completion Comments Status Date Phases 1 and 2 HCVS Milestone Table Submit Phase 1 Overall Jun 2014 Complete Integrated Plan Submit 6 Month Updates - -- ---` ---

Update 1 Dec 2014 Complete Update 2 Jun 2015 Complete Update 3 and Phase 2 Dec 2015 Complete Overall Integrated Plan Update 4 Jun 2016 Complete Update 5 Dec 2016 Complete Update 6 Jun 2017 Complete This submittal Update 7 Dec 2017 Not Started Update 8 Jun 2016 Not Started Update 9 Dec 2016 Not Started Phase 1 Specific Milestones Phase 1 Unit 2 Modifications Begin Conceptual Jun 2014 Complete Design Complete Conceptual Jun 2014 Complete Design Begin Detailed Design Jun 2015 Complete Complete Detailed Design and Issue Nov 2016 Complete Modification Package Begin Online Jun 2016 Complete Installation Page 2 of 19

Target Activity Milestone Completion Comments Status Date Phases 1 and 2 HCVS Milestone Table Complete Online Feb 2017 Complete Installation Begin Outage Feb 2017 Complete Installation Complete Outage Installation and put Mar 2017 Complete system into service Phase 1 Unit 2 Procedure Changes Operations Procedures Dec 2016 Complete Developed Maintenance Dec 2016 Complete Procedures Developed Procedure Changes Mar 2017 Complete Active Phase 1 Unit 2 Training Training Complete Dec 2016 Complete Phase 1 Unit 2 Completion Unit 2 RCVS Phase 1 Mar 2017 Complete Implementation Phase 1 Unit 1 Modifications Begin Conceptual Jun 2014 Complete Design Complete Conceptual Jun 2014 Complete Design Begin Detailed Design Jun 2015 Complete New target: Aug 2017 Complete Detailed based on revising the Design and Issue Mar 2017 Started design for tying-in to Modification Package primary containment Page 3 of 19

Target Activity Milestone Completion Comments Status Date Phases 1 and 2 HCVS Milestone Table Begin Online May 2017 Complete Installation Complete Online Feb 2018 Started Installation Begin Outage Feb 2018 Not Started Installation Complete Outage Installation and put Mar 2018 Not Started system into service Phase 1 Unit 1 Procedure Changes Operations Procedures Dec 2017 Started Developed Maintenance Dec 2017 Started Procedures Developed Procedure Changes Mar 2018 Not Started Active Phase 1 Unit 1 Training Training Complete Dec 2017 Started Phase 1 Completion Phase 1 Unit 1 Mar 2018 Not Started Implementation Phase 2 Specific Milestones Phase 2 Unit 1 Modifications Begin Conceptual Jun 2015 Complete Design Complete Conceptual Jun 2015 Complete Design i

Page 4 of 19

Target --- --- --------____~_~_---

Activity Milestone Completion Comments Status Date Phases 1 and 2 HCVS Milestone Table Completed Mar 2017 Begin Detailed Design Jun 2016 Complete due to Phase 1 detailed design and installation Complete Detailed New target: Aug 2017 Design and Issue Mar 2017 Started due to movement of the Modification Package start of detailed design New target: Aug 2017 Begin Online May 2017 Not Started based on completion of Installation detailed design Complete Online Feb 2018 Not Started Installation Begin Outage No outage work Feb 2018 Not Started Installation required Complete Outage No outage work Installation and put Mar 2018 Not Started required system into service Phase 2 Unit 1 Procedure Changes Operations Procedures Dec 2017 Not Started Developed Maintenance Dec 2017 Not Started Procedures Developed Procedure Changes Mar 2018 Not Started Active Phase 2 Unit 1 Training Training Complete Dec 2017 Not Started Phase 2 Unit 1 Completion Phase 2 Unit 1 Mar 2018 Not Started Implementation Submit Unit 1 Phases May 2018 Not Started Page 5 of 19

Target Activity Milestone Completion Comments Status Date Phases 1 and 2 HCVS Milestone Table 1 & 2 Full Compliance Report Phase 2 Unit 2 Modifications Begin Conceptual Jun 2015 Complete Design Complete Conceptual Jun 2015 Complete Design New Target: Feb 2018 Begin Detailed Design Jun 2017 Not Started following completion of Unit 1 detailed design Complete Detailed New Target: Aug 2018 Design and Issue Mar 2018 Not Started due to movement of the Modification Package start of detailed design New Target: Aug 2018 Begin Online May 2018 Not Started based on completion of Installation detailed design Complete Online Feb 2019 Not Started Installation Begin Outage No outage work Feb 2019 Not Started Installation required Complete Outage No outage work Installation and put Mar 2019 Not Started required system into service Phase 2 Unit 2 Procedure Changes Operations Procedures Dec 2018 Not Started Developed Maintenance Dec 2018 Not Started Procedures Developed Procedure Changes Mar 2019 Not Started Page 6 of 19

Target Activity Milestone Completion Comments Status Date Phases 1 and 2 HCVS Milestone Table Active Phase 2 Unit 2 Training Training Complete Dec 2018 Not Started Phase 2 Completion Phase 2 Unit 2 Mar 2019 Not Started Implementation Submit Unit 2 Phases 1 & 2 Full Compliance May 2019 Not Started Report

1. Rather than "as close as possible" (Ref. 7, pg. 14), the PCIVs will be located "as close as reasonably possible" (Ref. 3, Section 4.1.2.1.2) to the penetration into primary containment. (Ref. 9, Drawing M-959 Sheet 4)

2. The motive gas supply to the PCIVs will be nitrogen, not argon. (Ref. 7, pg. 10 &

15; Ref. 9, Design Considerations Summary (DCS) 4.1.33)

3. Downstream of the outboard PCIV, the piping classification changes from Safety Related to Non-Safety Related and Seismically Supported (i.e., Augmented Quality) (including the rupture disc). This is similar to safety classification changes for the existing Containment Vent & Purge System where piping downstream of the outboard PCIV is Seismically Supported and Non-Safety Related and then penetrates through Secondary Containment. This includes argon and nitrogen tubing. (Ref. 7, pg. 17; Ref. 9, DCS Sec. 4.1.4.2)

4. HCVS leak-off path isolation will be via pilot-operated 2-way valve located in the Reactor Building. The pneumatic pilot taps into the nitrogen supply to the upstream PCIV actuator, closing the leak-off pathway simultaneously with opening the upstream PCIV. Thus, it will not require separate manual action.

From Table 2-1 of Reference 7 (pg. 10), Primary Action 2 is combined with opening the upstream PCIV and inserted between Primary Actions 4 and 5 in sequence, prior to breaching the rupture disc with argon. Primary Action 6 will be reduced to opening and closing the downstream PCIV to cycle the vent. (Ref. 9, Dwg. M-138 Sheet 3)

Page 7 of 19

5. Radiation shielding for the FLEX pump or generator deployment locations is not required; the dose rates at the FLEX pump deployment locations are low enough for personnel habitability without shielding, and the FLEX generators are relocated to take advantage of shielding provided by the Reactor Building itself.

(Ref. 7, pg. 28; procedure LOA-FSG-002, Attachments B1, B2, and I; calculation L-004151)

WIN LaSalle expects to comply with the order implementation date and no relief/relaxation is required at this time.

6 Open Items from Combined Phase 1 and 2 Overalll lintLegratedl Ilan and InteHm Staff Evaluations The following tables provide a summary of the open items documented in the combined Phase 1 and 2 Overall Integrated Plan or the Interim Staff Evaluation (ISE) and the status of each item.

Combined Phases 1 and 2 OIP Status Open Items Phase 1 Open Items Perform radiological Complete. LaSalle calculation L-004151 evaluation for Phase 1 vent determines peak dose rates at FLEX and RCVS line impact on ERO actions Phase 2 activity locations. Adjustments have been made to either the timing or location of actions to manage dose below 5 REM to any individual performing ERO actions in most cases, with a small number of actions potentially greater than 5 REM, but not exceeding 10 REM.

The estimated dose is based on peak dose rates from LaSalle calculation L-004151, determined from a combination of all source term locations, and is a very conservative estimate. There is considerable margin to the maximum emergency response exposure guideline of 25 REM to any one individual performing ERO actions.

L-004151 is available on ePortal.

Page 8 of 19

Combined Phases 1 and 2 OIP Status Open Items Phase 2 Open Items 1 Evaluate feasibility of strategy Started. LaSalle calculation L-004151 indicates due to radiological conditions. that the affected Reactor Building will be uninhabitable 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> after the ELAP due to core damage. As a result, the hose connection point on elevation 710' will be relocated from the Reactor Building to the Diesel Corridor, and order of activities changed so that the hose connections on elevation 761' in the Reactor Building are made within the first hour after the ELAP. Dose rates at the FLEX/SAWA pump location are low enough that additional shielding is not required. Refueling strategies and other exterior actions will be adjusted as necessary based on actual event conditions.

L-004151 is available on ePortal.

2 Verify required modifications Started to support SAWA/SAWM.

No. Phase 1 Interim Staff 7 Status Evaluation Open Item Make available for NRC staff Complete for Unit 2. The motive and purge gas audit documentation of a systems will be isolated by at least one locked-method to disable RCVS closed manual valve in each system during during normal operation to normal operation. Main Control Room (MCR) provide assurances against controls will be via key-locked switches with inadvertent operation that also power normally de-energized. PCIVs are air-to-minimizes actions to enable open, spring/fail closed. Ref. 9 (DCS 4.1.19, RCVS operation following an 4.1.33, 4.1.35, 4.1.36) and procedure LGA-VQ-ELAP. 202 provide direction for these actions and are available on ePortal.

In-progress for Unit 1 following the concept described for Unit 2, above.

Page 9 of 19

2 Make available for NRC staff Complete for Unit 2. Calculation L-004114 audit the final sizing evaluation performs the sizing evaluation of the common for HCVS batteries/battery HCVS batteries and associated charger. The charger including incorporation results show a margin of approximately 7% after into FLEX DG loading 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> with all Unit 1 and Unit 2 HCVS loads calculation. drawing maximum current. The FLEX DG loading evaluations in ECs 396062 (DCS 4.1.35) and 396069 (DCS 4.1.35) show a margin on the more limited DG of 337 amps for future loads.

The HCVS battery charger rated input current is 8 amps per Ref. 9 (DCS 4.1.35). Therefore, there is sufficient margin in either FLEX DG to power the HCVS battery charger.

L-004114, the Design Consideration Summaries (DCSs) of the final revisions of ECs 396062 and 396069, and Ref. 9 are available on ePortal.

In-progress for Unit 1. As the battery is common to both units, Unit 1 detailed design needs only to verify battery loads are within those assumed in L-004114.

3 Make available for NRC staff Complete for Unit 2. Pneumatic system motive audit documentation of the force changed to nitrogen; see Section 4 of this HCVS argon pneumatic document, Ref. 9 (DCS 4.1.33), and calculation system design including sizing L-004117.

and location. L-004117 and Ref. 9 are available on ePortal.

In-progress for Unit 1; design will follow the same concept as Unit 2.

4 Make available for NRC staff Complete for Unit 2. The radiological evaluation audit an evaluation of in calculation L-004115 and temperature temperature and radiological evaluation in EC 392353 (Ref. 9, DCS 4.1.14) conditions to ensure that show no additional shielding or high temperature operating personnel can safely mitigation is required to safely access and access and operate controls operate controls and equipment.

and support equipment. L-004115 and Ref. 9 are available on ePortal.

In-progress for Unit 1; as Unit 1 design will follow the same concept as Unit 2, habitability evaluations are expected to be similar.

Page 10 of 19

5 Make available for NRC staff Complete for Unit 2. Calculation L-004097 audit analyses demonstrating shows that the RCVS has the capacity to vent that RCVS has the capacity to the steam/energy equivalent of 1 % of rated vent the steam/energy thermal power while maintaining containment equivalent of one percent of pressure below containment design pressure licensed/rated thermal power and PCPL.

(unless a lower value is L-004097 is available on ePortal.

justified), and that the suppression pool and the In-progress for Unit 1; design will follow the RCVS together are able to same concept as Unit 2.

absorb and reject decay heat, such that following a reactor shutdown from full power containment pressure is restored and then maintained below the primary containment design pressure and the primary containment pressure limit.

6 Make available for NRC staff Complete. LaSalle design complies with the audit the seismic and tornado reasonable tornado protection criteria of missile final design criteria for Reference 6. The seismic and tornado missile the RCVS stack. protection design is described in Ref. 9 (DCS 4.1.38) and evaluated in calculation L-004092.

Ref. 9 and L-004092 are available on ePortal.

Page 11 of 19

7 Make available for NRC staff Complete for Unit 2. Reference 9 (DCS 4.1.14) audit the descriptions of local includes the temperature and humidity conditions (temperature, evaluations and calculation L-004115 evaluates radiation and humidity) the radiological conditions. Both documents are anticipated during ELAP and available on ePortal.

severe accident for the In-progress for Unit 1; as Unit 1 design will follow components (valves, the same concept as Unit 2, component instrumentation, sensors, environmental conditions are expected to be transmitters, indicators, similar.

electronics, control devices, etc.) required for HCVS venting including confirmation that the components are capable of performing their functions during ELAP and severe accident conditions.

8 Make available for NRC staff Complete. FLEX communications strategies and audit documentation that equipment (as described in procedure demonstrates adequate LOA-FSG-010) will be utilized for HCVS. These communication between the methods are adequate for HCVS remote HCVS operation implementation.

locations and HCVS decision LOA-FSG-010 is available on ePortal.

makers during ELAP and severe accident conditions.

9 Provide a description of the Complete for Unit 2. An argon purge system is final design of the HCVS to provided which is designed to purge the vent address hydrogen detonation piping of a detonable mixture of hydrogen and and deflagration. oxygen after each vent cycle. Installed capacity is provided for the first 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> after ELAP, and additional argon bottles are stored in a FLEX building to continue operation past 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

Reference calculation L-004137 and Ref. 9 (DCS 4.1.33), available on ePortal.

In-progress for Unit 1; design will follow the same concept as Unit 2.

Page 12 of 19

10 Provide a description of the Complete. LaSalle wetwell vent line has a strategies for hydrogen control dedicated HCVS flowpath from the wetwell that minimizes the potential for penetration to the outside with no interconnected hydrogen gas migration and system. The discharge point meets the guidance ingress into the reactor of HCVS-FAQ-04 (Att. J of Reference 3). See building or other buildings. Ref. 9 (Dwg. M-138 Sheet 3), available on ePortal.

11 Make available for NRC staff Complete for Unit 2. See calculations L-003953, audit documentation of a L-004138 through L-004146, L-004161 through seismic qualification L-004166.

evaluation of HCVS All above calculations are available on ePortal.

components.

In-progress for Unit 1; design will follow the same concept as Unit 2.

Page 13 of 19

12 Make available for NRC staff Complete for Unit 2; Unit 1 design will follow the audit descriptions of all same concept as Unit 2.

instrumentation and controls New instrumentation and controls are described (existing and planned) in Reference 9 (DCS 4.1.36), and qualification necessary to implement this methods are per calculations shown in the table order including qualification below. All referenced documents are available methods.

on ePortal.

New Instruments Qualification Method Reference Calculations HCVS Temperature IEEE 344-1975/1987 (2TE-PC310, L-004161 2TT-PC311) L-004166 HCVS Radiation IEEE 344-1975 (2RE-PC320, L-004139 2RT-PC321) L-004166 HCVS PCIV Position IEEE 344-1975 Indication L-004140 HCVS Pneumatic IEEE 344-1975 Supply Pressure L-004143 2P1-PC450 HCVS Purge Supply IEEE 344-1975 Pressure (2P1-PC545, L-004143 2PT-PC546) L-004141 HCVS Electrical IEEE 344-1975 Supply Availability L-004138 ODC51 E HCVS Controls IEEE 344-1975 (OPM08J, manual L-004146 valves) L-004143 Existing instruments relied upon for initiation, operation, and monitoring of HCVS are qualified or evaluated to Regulatory Guide 1.97 and include the following: Dryweil pressure (1(2)PI-CM029), Wetwell pressure (1(2)PI-CM056), Wetwell level (1 (2)LI-CM1 92),

Wetwell water temperature (1(2)TI-CM037), and Reactor pressure (1 (2)C61 -RO1 1). (Ref. 9, DCS 4.1.14)

Page 14 of 19

13 Make available for NRC staff Complete for Unit 2. Procedures LGA-VQ-202 audit the procedures for HCVS and LOP-PC-09 contain all instructions for operation. operation of the RCVS.

Above procedures are available on ePortal.

In-progress for Unit 1; design will follow the same concept as Unit 2.

Phase 2 Interim Staff Status Evaluation Open Item 1 Licensee to confirm through Started.

analysis the temperature and radiological conditions to ensure Actions taken within the first hour (prior to start that operating personnel can of core damage) from the start of the ELAP are safely access and operate controls and support equipment. acceptable from an environmental and (ISE Section 3.3.1) radiological perspective without further evaluation.

Actions performed within the MCR are acceptable for the entire period of Sustained Operation per HCVS-FAQ-06 Assumption 049-21.

For actions within the Reactor Building and between 1 and 7 hours8.101852e-5 days <br />0.00194 hours <br />1.157407e-5 weeks <br />2.6635e-6 months <br />, a quantitative evaluation of expected dose rates has been performed per HCVS-FAQ-12 and found the dose rates at deployment locations including ingress/egress paths are acceptable. See calculation L-004151, available on ePortal. Note that no actions in the Reactor Building are planned for the unit in a severe accident after the first hour post-ELAP.

For ingress and egress paths outside the Reactor Building between 7 hours8.101852e-5 days <br />0.00194 hours <br />1.157407e-5 weeks <br />2.6635e-6 months <br /> and 7 days, when SAWA is being utilized, a quantitative evaluation of expected dose rates has been performed per HCVS-WP-02 and found the dose rates at deployment locations including ingress/egress paths are acceptable. See L-004151.

Page 15 of 19

Cautions will be added to procedures to provide guidance for high dose rate areas to minimize dose.

2 Licensee to evaluate the ingress Started.

and egress paths for the expected severe accident The location of SAWA equipment and controls conditions (temperature, including ingress and egress paths will be the humidity, radiation) for the sustained same or similar as FLEX and will be bounded by operating period. (ISE Section the FLEX evaluations for temperature and 3.3.2 3) humidity.

See the response to Phase 2 ISE Open Item #1 for radiation.

3 Licensee to demonstrate that Started.

containment failure as a result of overpressure can be prevented The wetwell vent has been designed to meet without a DW vent during severe NEI 13-02 Rev 1 guidance, which will ensure accident conditions. (ISE Section 3.3.3) that it is adequately sized to prevent containment overpressure under severe accident conditions.

The SAWM strategy will ensure that the wetwell vent remains functional for the period of sustained operation. LaSalle will follow the guidance (flow rate and timing) for SAWA/SAWM described in BWROG-TP-15-008 and BWROG-TP-15-011. These documents have been posted to the ePortal for NRC staff review. The wetwell vent will be opened prior to exceeding the PCPL value of 60 PSIG.

Therefore, containment over-pressurization is prevented without the need for a drywell vent.

Page 16 of 19

L Licensee shall demonstrate how Started.

the plant is bounded by the reference plant analysis that Reference Plant LaSalle shows the SAWM strategy is Torus freeboard Suppression pool successful in making it unlikely volume is 525,000' freeboard volume is that a DW vent is needed. (ISE gallons 977,404 gallons Section 3.3.3.1)

SAWA flow is 500 SAWA flow is 500 GPM at 8 hr followed GPM at 8 hr followed by 100 GPM from by 100 GPM from 12hrto168hr 12hrto168hr The above parameters for LaSalle compared to the reference plant that determines success of the SAWM strategy demonstrate that the reference plant values are bounding.

Therefore, the SAWM strategy implemented at LaSalle makes it unlikely that a DW vent is needed to prevent containment overpressure related failure.

'Peach Bottom available freeboard volume in gallons is estimated from nominal water level of 14.7 feet to 21 feet.

21 feet is the upper range of the wide range torus level instrument and the assumed loss of wetwell vent function.

The Peach Bottom torus is 31 feet in diameter.

5 Licensee to demonstrate that Started.

there is adequate communication between the LaSalle utilizes handheld radios in the talk-MCR and the operator at the around mode to communicate between the MCR FLEX pump during severe accident conditions. (ISE Section and the operator at the FLEX pump. This 3.3.3.4) communication method is the same as accepted in Order EA-12-049. These items will be powered and remain powered using the same methods as evaluated under EA-12-049 for the period of sustained operation, which may be longer than identified for EA-12-049.

Page 17 of 19

6 Licensee to demonstrate the Started.

SAWM flow instrumentation qualification for the expected For locations outside the Reactor Building environmental conditions. (ISE between 7 hours8.101852e-5 days <br />0.00194 hours <br />1.157407e-5 weeks <br />2.6635e-6 months <br /> and 7 days when SAWA is Section 3.3.3.4) being utilized, a quantitative evaluation of expected dose rates has been performed per HCVS-WP-02 and found the dose rates at deployment locations including ingress/egress paths are acceptable (Ref. calculation L-004151, available on ePortal). The selected instrument is designed for the expected flow rate, temperature and pressure for SAWA over the period of sustained operation.

SAWA Flow Expected SAWA Instrument Parameter Range Qualification 80 - 2300 gpm 100 - 500 gpm Up to 125 O F -25 to 101 O F 0 to 300 psi 0 to 250 psi

• I 1111==

r I 9 There are no potential impacts to the Interim Staff Evaluation(s) identified at this time.

References The following references support the updates to the combined Phases 1 and 2 Overall Integrated Plan described in this enclosure.

1. LaSalle's "Phase 1 Overall Integrated Plan in Response to June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number EA-13-109)," dated June 30, 2014 (Accession No. ML14184A016).

2. NRC Order Number EA-13-109, "Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation under Severe Accident Conditions" dated June 6, 2013 (Accession No. ML13143A321).

3. NEI 13-02, "Industry Guidance for Compliance with NRC Order EA-13-109, `To Modify Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation under Severe Accident Conditions," Revision 1, dated April 2015.

Page 18 of 19

4. NRC Interim Staff Guidance JLD-ISG-2013-02, "Compliance with Order EA 109, Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions," Revision 0, dated November 2013 (Accession No. ML133045836).

5. NRC Endorsement of industry "Hardened Containment Venting System (HCVS)

Phase 1 Overall Integrated Plan Template (EA-13-109) Rev 0" (Accession No. ML14128A219).

6. Industry White Paper HCVS-WP-04, "Missile Evaluation for HCVS Components 30 Feet Above Grade," Revision 0, dated August 17, 2015.

7. LaSalle's "Phase 1 (Updated) and Phase 2 Overall Integrated Plan in Response to June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number EA-13-109)," dated December 16, 2015 (Accession No. ML15352A109).

8. NRC Interim Staff Guidance JLD-ISG-2015-01, "Compliance with Phase 2 of Order EA-13-109, Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions,"

Revision 0, dated April 2015 (Accession No. ML15104A118).

9. Engineering Change EC 3923531 "U2 Hardened Containment Vent System (HCVS)." Revision 5 approved February 24, 2017.

10. NRC "Interim Staff Evaluation Relating to Overall Integrated Plan in Response to Phase 1 of Order EA-13-109," dated March 31, 2015.

11. NRC "Interim Staff Evaluation Relating to Overall Integrated Plan in Response to Phase 2 of Order EA-13-109," dated August 2, 2016.

Page 19 of 19