RS-15-150, Second Six-Month Status Report for 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.

Second Six-Month Status Report for 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.

ML15181A016
Person / Time
Site:	Limerick
Issue date:	06/30/2015
From:	Jim Barstow Exelon Generation Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
EA-13-109, RS-15-150, TAC MF4418, TAC MF4419
Download: ML15181A016 (11)

Text

Exelon Generation Order No. EA-13-109 RS-15-150 June 30, 2015 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Limerick Generating Station, Units 1 and 2 Renewed Facility Operating License Nos. NPF-39 and NPF-85 NRC Docket Nos. 50-352 and 50-353

Subject:

Second Six-Month Status Report For 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)

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-2015-01, "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 April 2015

3. NEI 13-02, "Industry Guidance for Compliance with NRC Order EA-13-109, BWR Mark I

& II Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions," Revision 1 , dated April 2015

4. 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

5. 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-14-060)

6. 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-14-304)

7. NRC letter to Exelon Generation Company, LLC, Limerick Generating 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.

MF4418 and MF4419), dated April 1, 2015

U.S. Nuclear Regulatory Commission Integrated Plan Report to EA-13-109 June 30, 2015 Page 2 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 of Reference 1.

Reference 1 required submission of a Phase 1 Overall Integrated Plan pursuant to Section IV, Condition D by June 30, 2014. Reference 2 endorses industry guidance document NEI 13-02, Revision 1 (Reference 3) with clarifications and exceptions identified in Reference 2. Reference 4 provided the EGC initial answer to the Order regarding reliable hardened containment vents capable of operation under severe accident conditions. Reference 5 provided the Limerick Generating Station, Units 1 and 2 Phase 1 Overall Integrated Plan.

Reference 1 requires submission of a status report at six-month intervals following submittal of the Phase 1 overall integrated plan. Reference 3 provides direction regarding the content of the status reports. Reference 6 provided the first six-month status report pursuant to Section IV, Condition D.3 of Reference 1 for Limerick Station. The purpose of this letter is to provide the second six-month status report for Phase 1 pursuant to Section IV, Condition D.3, of Reference 1, that delineates progress made in implementing the requirements of Reference 1.

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 Reference 7.

This letter contains no new regulatory commitments. If you have any questions regarding this report, please contact David P. Helker at 610-765-5525.

I declare under penalty of perjury that the foregoing is true and correct. Executed on the 301h day of June 2015.

Respectfully submitted, c~ ~

James Barstow Director - Licensing & Regulatory Affairs Exelon Generation Company, LLC

Enclosure:

Limerick Generating Station, Units 1 and 2 Second Six-Month Status Report for Phase 1 Implementation of Order EA-13-109, "Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions"

U.S. Nuclear Regulatory Commission Integrated Plan Report to EA-13-109 June 30, 2015 Page 3 cc: Director, Office of Nuclear Reactor Regulation NRC Regional Administrator - Region I NRC Senior Resident Inspector - Limerick Generating Station, Units 1 and 2 NRC Project Manager, NRA - Limerick Generating Station, Units 1 and 2 Mr. Charles H. Norton, NRR/JLD/PPSD/JOMB, NRC Mr. John D. Hughey, NRR/JLD/JOMB, NRC Director, Bureau of Radiation Protection - Pennsylvania Department of Environmental Resources R. R. Janati, Chief, Division of Nuclear Safety, Pennsylvania Department of Environmental Protection, Bureau of Radiation Protection

Enclosure Limerick Generating Station, Units 1 and 2 Second Six-Month Status Report for Phase 1 Implementation of Order EA-13-109, "Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions" (7 pages)

Enclosure Limerick Generating Station, Units 1 and 2 Second Six Month Status Report for Phase 1 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 Limerick Generating Station, Units 1 and 2 developed an Overall Integrated Plan (Reference 1 in Section 8), 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. This enclosure provides an update of milestone accomplishments since submittal of the Phase 1 First Six Month Status Report, including any changes to the compliance method, schedule, or need for relief/relaxation and the basis, if any.

2 Milestone Accomplishments The following milestones have been completed since December 01, 2014, and are current as of June 01, 2015.

• Second Six-Month Update (complete with this submittal) 3 Milestone Schedule Status The following provides an update to Part 5 included in the Overall Integrated Plan (OIP). 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.

The revised milestone schedule does not impact the order implementation date.

Note: Phase 2 implementation milestones for Limerick will be provided with the December 2015 OIP submittal.

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Limerick Generating Station, Units 1 and 2 Second Six Month Status Report for the Implementation of HCVS Phase 1 June 30, 2015 Target Activity Milestone Completion Comments Status Date Phase 1 HCVS Milestone Table Submit Overall Integrated Plan June 2014 Complete Submit 6 Month Updates:

December Update 1 Complete 2014 Complete Update 2 June 2015 with this submittal December Simultaneous with Update 3 Not Started 2015 Phase 2 OIP Update 4 June 2016 Not Started December Update 5 Not Started 2016 Update 6 June 2017 Not Started December Update 7 Not Started 2017 Modifications:

Hold preliminary/conceptual design July 2014 Complete meeting Started piping Modifications Evaluation March 2016 Started layout and line sizing Unit 2 Design Engineering On-March 2016 Started Site/Complete Unit 2 Implementation Outage April 2017 Not Started Unit 2 Walk Through April 2017 Not Started Demonstration/Functional Test Unit 1 Design Engineering On-March 2017 Started site/Complete Unit 1 Implementation Outage April 2018 Not Started Unit 1 Walk Through Demonstration/Functional Test April 2018 Not Started Page 2 of 7

Limerick Generating Station, Units 1 and 2 Second Six Month Status Report for the Implementation of HCVS Phase 1 June 30, 2015 Target Activity Milestone Completion Comments Status Date Phase 1 HCVS Milestone Table Procedure Changes Active Operations Procedure Changes December Not Started Developed 2016 Site Specific Maintenance Procedure December Not Started Developed 2016 Unit 2 Procedure Changes Active April 2017 Not Started Unit 1 Procedure Changes Active April 2018 Not Started Training:

Training Complete March 2017 Not Started Completion Unit 2 HCVS Phase 1 Implementation April 2017 Not Started Submit Unit 2 Phase 1 Completion Report June 2017 Not Started Unit 1 HCVS Phase 1 Implementation April 2018 Not Started Submit Unit 1 Phase 1 Completion Report June 2018 Not Started Full Site HCVS Phase 1 Implementation April 2018 Not Started 4 Changes to Compliance Method The following changes are made to the compliance method for Phase 1 as documented in the Phase 1 Overall Integrated Plan (Reference 1):

• Limerick Generating Station HCVS Design has decided to replace all references to a Secondary Containment Isolation Valve (SCIV) with a rupture disc for a pressure sufficient to withstand leakage through the downstream Primary Containment Isolation Valve (PCIV) during a Design Basis Accident or testing.

• A purge system has been chosen as the method to prevent hydrogen deflagration. The purge system will be used to rupture the disc to allow anticipatory venting.

5 Need for Relief/Relaxation and Basis for the Relief/Relaxation Limerick Generating Station expects to comply with the order implementation date; therefore, no relief/relaxation is required at this time.

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Limerick Generating Station, Units 1 and 2 Second Six Month Status Report for the Implementation of HCVS Phase 1 June 30, 2015 6 Open Items from Overall Integrated Plan and Interim Staff Evaluation The following tables provide a summary of the open items documented in the Phase 1 Overall Integrated Plan or the Interim Staff Evaluation (ISE) and the status of each item.

Overall Integrated Plan Phase 1 Open Item Status Determine how Motive Power and/or HCVS Battery Deleted (closed to ISE Open Item Power will be disabled during normal operation. Number 1 below)

Confirm that the Remote Operating Station (ROS) will be Deleted (closed to ISE Open Item in an accessible area following a severe accident. Number 3 below)

Determine wetwell line size to meet 1% venting criteria. Deleted (closed to ISE Open Item Number 4 below)

Confirm suppression pool heat capacity. Deleted (closed to ISE Open Item Number 4 below)

Determine the approach for combustible gases. Deleted (closed to ISE Open Item Numbers 9 and 1O below)

Provide procedures for HCVS Operation. Deleted (closed to ISE Open Item Number 13 below)

Interim Staff Evaluation Open Item Status 1 Make available for NRC staff audit a description of how HCVS Started (Reference 6) de power and/or motive power will be disabled during normal operation to provide assurances against inadvertent operation, but also minimize actions to enable HCVS operation during an ELAP.

2 Make available for NRC staff audit the final sizing evaluation for Not Started HCVS batteries/battery charger including incorporation into FLEX DG loading calculation .

3 Make available for NRC staff audit an evaluation of temperature Started - The evaluation and radiological conditions to ensure that operating personnel of temperature and can safely access and ope~ate controls and support equipment. radiological conditions under severe accident conditions has been started.

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Limerick Generating Station, Units 1 and 2 Second Six Month Status Report for the Implementation of HCVS Phase 1 June 30, 2015 4 Make available for NRC staff audit analyses demonstrating that Started - The required HCVS has the capacity to vent the steam/energy equivalent of one percent vent one percent of licensed/rated thermal power (unless a lower capacity at the lower of value is justified), and that the suppression pool and the HCVS Primary Containment together are able to absorb and reject decay heat, such that Pressure Limit or following a reactor shutdown from full power containment containment design pressure is restored and then maintained below the primary pressure will be verified containment design pressure and the primary containment using Reactor Excursion pressure limit. and Leak Analysis Program (RELAP). In addition, Modular Accident Analysis Program (MAAP) analyses will be credited to verify that venting can be delayed for at least three hours and that anticipatory venting can be credited to maintain Reactor Core Isolation Cooling (RCIC) function al.

5 Make available for NRC staff audit the seismic and tornado Not Started missile final design criteria for the HCVS stack.

6 Make available for NRC staff audit the descriptions of local Not Started conditions (temperature, radiation and humidity) anticipated during ELAP and severe accident for the components (valves, instrumentation, sensors, transmitters, indicators, 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.

7 Make available for NRC staff audit documentation of the HCVS Not Started nitrogen pneumatic system design including sizing and location.

8 Make available for NRC staff audit documentation that Not Started demonstrates adequate communication between the remote HCVS operation locations and HCVS decision makers during ELAP and severe accident conditions.

9 Provide a description of the final design of the HCVS to address Started - The design will hydrogen detonation and deflagration. credit a purge system to prevent deflagration and detonation.

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Limerick Generating Station, Units 1 and 2 Second Six Month Status Report for the Implementation of HCVS Phase 1 June 30, 2015 10 Provide a description of the strategies for hydrogen control that Started - The vent path minimizes the potential for hydrogen gas migration and ingress will rely on dedicated into the reactor building or other buildings. suppression pool paths and dedicated PCIVs in each Limerick unit with no interconnected systems. The vent path will rely on a purge system to prevent line failure due to hydrogen deflagration and detonation.

11 Make available for NRC staff audit documentation of a seismic Not Started qualification evaluation of HCVS components.

12 Make available for NRC staff audit descriptions of all Not Started instrumentation and controls (existing and planned) necessary to implement this order including qualification methods.

13 Make available for NRC staff audit the procedures for HCVS Not Started operation.

7 Interim Staff Evaluation Impacts There are no potential impacts to the Interim Staff Evaluation identified at this time.

8 References The following references support the updates to the Phase 1 Overall Integrated Plan described in this enclosure.

1. Limerick Generating Station, Units 1 and 2 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

2. 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

3. 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 Page 6of7

Limerick Generating Station, Units 1 and 2 Second Six Month Status Report for the Implementation of HCVS Phase 1 June 30, 2015

4. NRC Interim Staff Guidance JLD-ISG-2015-01, "Compliance with Order EA-13-109, Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation under Severe Accident Conditions," Revision O, dated April 2015 (Accession No. ML15104A118)

5. NRC Endorsement of Industry "Hardened Containment Venting System (HCVS) Phase 1 Overall Integrated Plan Template (EA-13-109) Rev O," dated May 14, 2014 (Accession No. ML14128A219)

6. Limerick Generating Station, Units 1 and 2 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, dated December 17, 2014

7. NRC Interim Staff Evaluation by the Office of Nuclear Reactor Regulation Related to Order EA-13-109 Phase 1, Modifying Licenses with regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions, Exelon Generation Company, LLC, Limerick Generating Station, Units 1 and 2, Docket Nos. 50-352 and 50-353, dated April 1, 2015 (Accession No. ML15082A433)

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