RS-15-148, 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..

ML15181A220
Person / Time
Site:	Dresden
Issue date:	06/30/2015
From:	Kaegi G Exelon Generation Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
EA-13-109, RS-15-148
Download: ML15181A220 (11)

Text

ExelonGenera Order No. EA-13-109 RS-15-148 June 30, 2015 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Dresden Nuclear Power Station, Units 2 and 3 Renewed Facility Operating License Nos. DPR-19 and DPR-25 NRC Docket Nos. 50-237 and 50-249

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-14-058)

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-14-302)

7. NRC letter to Exelon Generation Company, LLC, Dresden Nuclear Power Station, Units 2 and 3 Interim Staff Evaluation Relating to Overall Integrated Plan in Response to Phase 1 of Order EA-13-109 (Severe Accident Capable Hardened Vents) (TAC No.

MF4462 and MF4463), dated February 11,2015

U.S. Nuclear Regulatory Commission Integrated Plan Report to EA-13-109 June 30, 2015 Page 2 On June 6, 2013, the U.S. 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 Dresden Nuclear Power Station, Units 2 and 3 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 Dresden 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 30th day of June 2015 Respectfully submitted, Glen T. Kaegi Director - Licensing & Regulatory Affairs Exelon Generation Company, LLC

Enclosure:

Dresden Nuclear Power Station, Units 2 and 3 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 III NRC Senior Resident Inspector - Dresden Nuclear Power Station, Units 2 and 3 NRC Project Manager, NRR - Dresden Nuclear Power Station, Units 2 and 3 Mr. Charles H. Norton, NRR/JLD/PPSD/JOMB, NRC Mr. John P. Boska, NRR/JLD/JOMB, NRC Illinois Emergency Management Agency - Division of Nuclear Safety

Enclosure Dresden Nuclear Power Station, Units 2 and 3 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 Dresden Nuclear Power Station, Units 2 and 3 Second 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 Dresden Nuclear Power Station, Units 2 and 3 (Dresden Station) 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 Overall Integrated Plan, including any changes to the compliance method, schedule, or need for relief/relaxation and the basis, if any.

2 Milestone Accomplishments The following milestone(s) have been completed since the development of the Overall Integrated Plan (Reference 1), and are current as of June 30, 2015.

• Held preliminary/conceptual design meeting

• Kickoff meeting for S&L contract for Engineering Services, December 2, 2014

• First Six-Month Update, December 30, 2014

• 50% Design Review held on May 20, 2015 and May 26, 2015

• Second Six-Month Update (complete with this submittal) 3 Milestone Schedule Status The following provides an update to Attachment 2 of the Overall Integrated Plan (01P). It provides the activity status of each item, and whether the expected completion date has changed. The dates are planning dates which are subject to change as design and implementation details are developed.

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

Target Comments Activity Milestone Completion Status Date Phase 1 HCVS Milestone Table Submit Overall Integrated Plan June 2014 Complete Submit 6 Month Updates:

Page 1 of 7

Dresden Nuclear Power Station, Units 2 and 3 Second Six Month Status Report for the Implementation of HCVS Phase 1 June 30, 2015 Target Comments Activity Milestone Completion Status Date Phase 1 HCVS Milestone Table December Update 1 Complete 2014 Complete with Update 2 June 2015 this submittal December Update 3 Not Started 2015 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 June 2014 Complete meeting December Kickoff Meeting with S&L Complete 2014 U3 Initial Design Engineering October 2015 Started Modification Complete U3 Implementation Outage (Phase 1) October 2016 Not Started U2 Initial Design Engineering October 2016 Not Started Modification Complete Operations Procedure Changes November Not Started Developed 2016 Site Specific Maintenance Procedure November Not Started Developed 2016 November U3 Training Complete Not Started 2016 November U3 Procedure Changes Active Not Started 2016 U3 Walk Through November Demonstration/Functional Test 2016 U2 Implementation Outage October 2017 Not Started U2 Training Complete November Not Started Page 2 of 7

Dresden Nuclear Power Station, Units 2 and 3 Second Six Month Status Report for the Implementation of HCVS Phase 1 June 30, 2015 Target Comments Activity Milestone Completion Status Date Phase 1 HCVS Milestone Table 2017 November U2 Procedure Changes Active Not Started 2017 U2 Walk Through November Not Started Demonstration/Functional Test 2017 Submit Completion Report May 2018 Not Started 4 Changes to Compliance Method Dresden intends to make the following changes to the compliance method for Phase 1 as documented in the Phase 1 Overall Integrated Plan (Reference 1):

• The Dresden HCVS Design is replacing references to a Secondary Containment Isolation Valve (SCIV) with a rupture disc rated for a pressure sufficient to withstand leakage through the downstream PCIV during a Design Basis Accident or LLRT.

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

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

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.

Open Open Items from 01P Status Item Confirm that at least 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> battery coping Deleted. Closed to ISE Open Item time is available. number 1.

2 Determine actions to enable wetwell (WW) Deleted. Closed to ISE Open Item venting following a flooding around the torus. number 2.

Determine how Motive Power and/or HCVS Deleted. Closed to ISE Open Item Battery Power will be disabled during normal number 3.

operation.

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Dresden Nuclear Power Station, Units 2 and 3 Second Six Month Status Report for the Implementation of HCVS Phase 1 June 30 2015 4 Confirm that the Remote Operating Station Deleted. Closed to ISE Open Item (ROS) will be in an accessible area following number 12.

a Severe Accident (SA).

5 Confirm diameter on new common HCVS Deleted. Closed to ISE Open Item Piping. number 5.

6 Confirm suppression pool heat capacity. Deleted. Closed to ISE Open Item number 6.

7 Determine the approach for combustible Deleted. Closed to ISE Open Item gases. number 7.

8 Provide procedures for HCVS Operation. Deleted. Closed to ISE Open Item number 18.

Interim Staff Evaluation (ISE) Open Items Status 1 Make available for NRC staff audit Complete. EC 391973 Rev. 0 was documentation confirming that at least 6 completed to evaluate proposed battery hours battery coping time is available, load shed to support FLEX events. The evaluation addressed both 125V and 250V battery systems. The evaluation identified that with the load shed, the 125V and 250V batteries will maintain acceptable capacity for a minimum of six (6) hours. This time supports the FLEX Strategy time line actions.

2 Make available for NRC staff audit Started.

documentation that confirms the ability to operate HCVS following flooding around the suppression pool.

3 Make available for NRC staff audit Started.

documentation of a method to disable HCVS during normal operation to provide assurances against inadvertent operation that also minimizes actions to enable HCVS operation following an ELAP.

4 Make available for NRC staff audit the Started.

seismic and tornado missile final design criteria for the HCVS stack.

5 Make available for NRC staff audit Started. Refer to the response to ISE documentation of the licensee design effort to open item 6.

confirm the diameter on the new common HCVS piping.

6 Make available for NRC staff audit analyses Started. The required 1% vent capacity demonstrating that HCVS has the capacity to at the lower of PCPL or containment vent the steam/energy equivalent of one design pressure is being verified using percent of licensed/rated thermal power RELAP which models the line size and (unless a lower value is justified), and that the routing.

suppression pool and the HCVS together are In addition, MAAP analyses are being Page 4 of 7

Dresden Nuclear Power Station, Units 2 and 3 Second Six Month Status Report for the Implementation of HCVS Phase 1 June 30, 2015 able to absorb and reject decay heat, such credited to verify that venting can be that following a reactor shutdown from full delayed for at least three (3) hours, power containment pressure is restored and which supports assuming a maximum then maintained below the primary decay heat rate of 1%.

containment design pressure and the primary containment pressure limit.

7 Provide a description of the final design of the Started. Argon purge system design in HCVS to address hydrogen detonation and progress.

deflagration.

8 Make available for NRC staff audit Started.

documentation of a determination of seismic adequacy for the ROS location.

9 Make available for NRC staff audit Not Started.

documentation that demonstrates adequate communication between the remote HCVS operation locations and HCVS decision makers during ELAP and severe accident conditions.

10 Provide a description of the strategies for Started. As described in the 01P, the hydrogen control that minimizes the potential HCVS torus vent path in each Dresden for hydrogen gas migration and ingress into unit, starting at and including the the reactor building or other buildings. downstream PCIV, will be a dedicated HCVS flow path. There are no interconnected systems downstream of the downstream, dedicated HCVS PCIV.

Interconnected systems are upstream of the downstream HCVS PCIV and are isolated by normally shut, fail shut PCIVs which, if open, would shut on an ELAP.

There is no shared HCVS piping between the two units.

The vent path will rely on an Argon purge system to prevent line failure due to hydrogen deflagration and detonation.

11 Provide descriptions of design details that Started. Refer to the response to ISE minimize unintended cross flow of vented item 10. This eliminates the possibility of fluids within a unit and between units on the cross flow of vented fluids within a unit site. and between the two units.

12 Make available for NRC staff audit an Started. Component location design in evaluation of temperature and radiological progress. The HCVS primary control conditions to ensure that operating personnel panel will be located in the Main Control can safely access and operate controls and Room (MCR).

support equipment.

13 Make available for NRC staff audit the final Started.

sizing evaluation for HCVS batteries/battery charger including incorporation into FLEX DG loading calculation.

14 Make available for NRC staff audit Started. Nitrogen system design in documentation of the HCVS nitrogen Page 5 of 7

Dresden Nuclear Power Station, Units 2 and 3 Second Six Month Status Report for the Implementation of HCVS Phase 1 June 30, 2015 pneumatic system design including sizing and progress.

location.

15 Make available for NRC staff audit Started. Instrument design in progress.

descriptions of all instrumentation and controls (existing and planned) necessary to implement this order including qualification methods.

16 Make available for NRC staff audit the Started. Component location design in descriptions of local conditions (temperature, progress. The HCVS primary control radiation and humidity) anticipated during panel will be located in the MCR.

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.

17 Make available for NRC staff audit Started. The existing containment documentation of an evaluation verifying the isolation valves are being evaluated for existing containment isolation valves, relied their performance under wetwell venting upon for the HCVS, will open under the conditions.

maximum expected differential pressure during BDBEE and severe accident wetwell venting.

18 Make available for NRC staff audit Not Started.

procedures for HCVS operation.

7 Interim Staff Evaluation Impacts There are currently no 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. Dresden Nuclear Power Station, Units 2 and 3, 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-14-058.

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.

3. NEI 13-02 [Rev. 1], "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" dated April 2015.

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Dresden Nuclear Power Station, Units 2 and 3 Second Six Month Status Report for the Implementation of HCVS Phase 1 June 30, 2015

4. NRC Interim Staff Guidance JLD-ISG- 2015-01 [Rev. 0], "Compliance with Order EA 109, Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions", 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. 0," dated May 14, 2014 (Accession No. ML14128A219).

6. NRC letter to Exelon Generation Company, LLC, Dresden Nuclear Power Station, Units 2 and 3 Interim Staff Evaluation Relating to Overall Integrated Plan in Response to Phase 1 of Order EA-13-109 (Severe Accident Capable Hardened Vents) (TAC No. MF4462 and MF4463), dated February 11,2015 Page 7 of 7