NL-16-0726, Fourth Six-Month Status Report of the Implementation of the Commission Order with Regard to Requirements for Reliable Hardened Containment Vents (EA-13-109)

Fourth Six-Month Status Report of the Implementation of the Commission Order with Regard to Requirements for Reliable Hardened Containment Vents (EA-13-109)

ML16165A184
Person / Time
Site:	Hatch
Issue date:	06/13/2016
From:	Pierce C Southern Co, Southern Nuclear Operating Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
EA-13-109, NL-16-0726
Download: ML16165A184 (11)

Text

Charles R. Pierce Regulatory Affairs Director June 13, 2016 Docket Nos.: 50-321 50-366 Southern Nuclear Operating Company, Inc.

40 Inverness Center Parkway Post Office Box 1295 Birmingham, AL 35201 Tel 205.992.7872 Fax 205.992.7601 U. S. Nuclear Regulatory Commission ATIN: Document Control Desk Washington, D. C. 20555-0001 SOUTHERN*\\

NUCLEAR A SOUTHERN COMPANY NL-16-0726 Edwin I. Hatch Nuclear Plant-Units 1 and 2

References:

Fourth Six-Month Status Report of the Implementation of the Commission Order with Regard to Requirements for Reliable Hardened Containment Vents (EA-13-1 09)

1. NRC Order Number EA-13-1 09, Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions, dated June 6, 2013.

2. SNC Letter, Edwin I. Hatch Nuclear Plant-Units 1 and 2 Phase 1 Overall Integrated Plan in Response to June 6, 2013 Commission Order Modifying Licenses with Regard to Requirements for Reliable Hardened Containment Vents (EA-13-109), dated June 27,2014.

3. SNC Letter, Edwin I. Hatch Nuclear Plant-Units 1 and 2 Third Six-Month Status Report of the Implementation of Commission Order with Regard to Requirements for Reliable Hardened Containment Vents (EA-13-109), dated December 23, 2015.

Ladies and Gentlemen:

On June 6, 2013, the Nuclear Regulatory Commission (NRC) issued an Order (Reference 1) to Southern Nuclear Operating Company (SNC). Reference 1 was immediately effective and directs the Edwin I. Hatch Nuclear Plant-Units 1 and 2 (HNP) to install 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. Specific requirements are outlined in Attachment 2 of Reference 1.

In addition, Reference 1 also required submission of a Phase 1 overall integrated plan pursuant to Section IV, Condition D, and status reports at six-month intervals thereafter. SNC submitted the Phase 1 overall integrated plan (OIP) by letter dated June 27, 2014 (Reference 2). The third six-month update for Phase 1 of the Order included the required HCVS Phase 2 OIP submittal.

The consolidated HCVS Phase 1 and 2 OIP document (Reference 3) provided a list of the Phase 1 OIP open items, and addressed the NRC Interim Staff Evaluation open items for Phase 1. This letter is being submitted to satisfy the requirements for providing the six-month updates for Phase 1 and 2 of the Order in accordance with Section IV, Condition D.3, of Reference 1.

U.S. Nuclear Regulatory Commission NL-16-0726 Page2 This letter contains no new NRC commitments. If you have any questions, please contact John Giddens at 205.992.7924.

Mr. C. A. Pierce states he is the Regulatory Affairs Director for Southern Nuclear Operating Company, is authorized to execute this oath on behalf of Southern Nuclear Operating Company and, to the best of his knowledge and belief, the facts set forth in this letter are true.

Respectfully Jl1>mitted, c~~

C. A. Pierce Regulatory Affairs Director CRP/JMG/MRE before me this J_j_ day of ~ 12016.

~

My commission expires:

/D~ 'l*;)c/1

Enclosure:

Fourth Six-Month Status Report Regarding Requirements for Reliable Hardened Containment Vents (EA-13-1 09) cc:

Southern Nuclear Operating Company Mr. S. E. Kuczynski, Chairman, President & CEO Mr. D. G. Bost, Executive Vice President & Chief Nuclear Officer Mr. D. A. Vineyard, Vice President-Hatch Mr. M. D. Meier, Vice President-Regulatory Affairs Mr. B. J. Adams, Vice President-Engineering Mr. D. A. Madison, Vice President-Fleet Operations Mr. G. L. Johnson, Regulatory Affairs Manager-Hatch RType: CHA02.004 U. S. Nuclear Regulatory Commission Mr. W. M. Dean, Director of the Office of Nuclear Reactor Regulations Mr. C. Haney, Regional Administrator Mr. M. D. Orenak, NRR Senior Project Manager-Hatch Mr. D. H. Hardage, Senior Resident Inspector-Hatch Ms. J. A. Kratchman, NRRIJLD/PMB Mr. E. E. Bowman, NRRIDPRIPGCB State of Georgia Mr. J. H. Turner, Director-Environmental Protection Division

Edwin I. Hatch Nuclear Plant - Units 1 and 2 Fourth Six-Month Status Report of the Implementation of the Commission Order with Regard to Requirements for Reliable Hardened Containment Vents (EA-13-109)

Enclosure Fourth Six-Month Status Report Regarding Requirement for Reliable Hardened Containment Vents (EA-13-109)

Enclosure to NL-16-0726 Fourth Six-Month Status Report of Vent Order Implementation Edwin I. Hatch Nuclear Plant - Units 1 and 2 Fourth Six Month Status Report for the Implementation of Order EA-13-109 1

Introduction Southern Nuclear Operating Company developed an Overall Integrated Plan (Reference 1 and 8) for the Edwin I. Hatch Nuclear Plant-Units 1 and 2 (HNP) documenting the installation of a Hardened Containment Vent System (HCVS). Starting with this six month status report, updates of milestone accomplishments will be based on the combined Phase 1 and 2 Overall Integrated Plan dated December 23, 2015.

HNP developed an updated and combined Phase 1 and 2 Overall Integrated Plan (Reference 8), documenting:

1. 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 strategy that makes it unlikely that a drywall 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 combined Phase 1 and 2 Overall Integrated Plan (Reference 8), 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 combined Phase 1 and 2 Overall Integrated Plan (Reference 8), and are current as of April 30, 2016.

None 3

Milestone Schedule Status The following provides an update to Attachment 2 of the combined Phase 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.

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

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Enclosure to NL-16-0726 Fourth Six-Month Status Report of Vent Order Implementation Phase 1 and 2 HCVS Milestone Table Milestone Target Activity Comments Completion Status Date Submit Overall Integrated Plan Jun.2014 Complete Submit 6 Month Updates:

Update 1 Dec.2014 Complete Update 2 Jun.2015 Complete Update 3 Dec.2015 Complete Simultaneous with Phase 2 OIP Update 4 Jun. 2016 Complete with this submittal Update 5 Dec.2016 Not Started Update 6 Jun.2017 Not Started Update 7 Dec.2017 Not Started Phase 1 Specific Milestones Phase 1 Modifications:

Hold preliminary/conceptual design Jun.2014 Complete meeting Unit 1 Design Engineering On-Feb.2017 Started Current Projection site/Complete Oct. 2016 Unit 1 Implementation Outage Mar. 2018 Not Started Unit 1 Walk Through Mar. 2018 Not Started Demonstration/Functional Test Unit 2 Design Engineering On-May 2016 Started Current Projection site/Complete Aug. 2016 Unit 2 Walk Through Mar. 2017 Not Started Demonstration/Functional Test Unit 2 Implementation Outage Mar. 2017 Not Started Phase 1 Procedure Changes Operations Procedure Changes Dec.2016 Not Started Developed Site Specific Maintenance Procedure Dec.2016 Not Started Developed Procedure Changes Active Mar. 2017 Not Started E-2

Enclosure to NL-16-0726 Fourth Six-Month Status Report of Vent Order Implementation Milestone Target Activity Comments Completion Status Date Phase 1 Training:

Training Complete Dec.2016 Not Started Current Projection Mar. 2018 Phase 1 Completion Unit 2 HCVS Implementation Mar. 2017 Started Unit 1 HCVS Implementation Mar. 2018 Started Full Site HCVS Implementation Mar. 2018 Started Phase 2 Specific Milestones Phase 2 Modifications:

Hold preliminary/conceptual design Apr. 2016 Started No modifications meeting expected.

Engineering evaluations and associated non-modification changes scope definition by Mar 2017 Unit 1 Design Engineering On-Feb.2017 Not Started No modifications site/Complete expected.

Engineering evaluations and associated non-modification changes by Oct 2017 Unit 1 Walk Through Mar. 2018 Not Started Demonstration/Functional Test Unit 1 Implementation Outage Mar. 2018 Not Started Unit 2 Design Engineering On-Feb.2018 Not Started No modifications site/Complete expected.

Engineering evaluations and associated non-modification changes by Oct 2018 Unit 2 Walk Through Mar. 2019 Not Started Demonstration/Functional Test Unit 2 Implementation Outage Mar. 2019 Not Started E-3

Enclosure to NL-16-0726 Fourth Six-Month Status Report of Vent Order Implementation Milestone Target Activity Comments Completion Status Date Phase 2 Procedure Changes Operations Procedure Changes Sep.2017 Not Started Current Projection Developed Feb. 2018 Site Specific Maintenance Procedure Dec.2017 Not Started Developed Procedure Changes Active Mar. 2018 Not Started Phase 2 Training:

Training Complete Dec.2017 Not Started Phase 2 Completion Unit 1 HCVS Implementation Mar. 2018 Not Started Submit Unit 1 Phase 1 and 2 May 2018 Not Started Completion Report Unit 2 HCVS Implementation Mar. 2019 Not Started Full Site HCVS Implementation Mar. 2019 Not Started Submit Unit 2 and site Completion May2019 Not Started Report [60 days after full site compliance]

1 Changes to Compliance Method There are no changes to the compliance method as documented in the Phase 1 and 2 Overall Integrated Plan (Reference 8).

2 Need for Relief/Relaxation and Basis for the Relief/Relaxation Edwin I. Hatch Nuclear Plant-Units 1 and 2, expect to comply with the order implementation date and no relief/relaxation is required at this time.

3 Open Items from Combined Phase 1 and 2 Overall Integrated Plan and Interim Staff Evaluation The following tables provide a summary of the open items documented in the combined Phase 1 and 2 Overall Integrated Plan, the Phase 1 Interim Staff Evaluation (ISE) or Phase 2 Staff Evaluation (anticipated) and the status of each item.

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Enclosure to NL-16-0726 Fourth Six-Month Status Report of Vent Order Implementation Combined Phase 1 and 2 OIP Open Item Status/Comment Phase 1 Open Items 1

Determine location of Dedicated HCVS Battery transfer switch Complete (ref. 8) 2 Determine location of back-up nitrogen bottles Complete (ref. B) 3 Evaluate location of Portable DG for accessibility under Severe Complete {ref. 8)

Accident HCVS use 4

Confirm suppression pool heat capacity Complete {ref. 8) 5 Determine location of HCVS Remote Operating Station (ROS)

Complete (ref. B)

State which approach or combination of approaches Plant Hatch 6

decides to take to address the control of flammable gases, clearly Complete (ref. B) demarcating the segments of vent system to which an approach applies 7

Evaluate SGTS Valve Leakage utilizing criteria from NEI HCVS-Confirmatory action FAQ-05 In progress B

Identify qualification method used for HCVS instruments In progress Evaluate HCVS monitoring location for accessibility, habitability, 9

staffing sufficiency, and communication capability with Vent-use Confirmatory action decision makers In progress 10 Perform severe accident evaluation for FLEX DG use post 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> Confirmatory action actions In progress 11 Determine the control document for HCVS out of service time Complete criteria Interim Staff Evaluation Open Item Status Phase 1 ISE Items

1. Make available for NRC staff audit the location of the ROSs.

In progress (same as 5 above)

2. Make available for NRC staff audit the location of the dedicated Available (same as 1 above)

HCVS battery transfer switch.

3. Make available for NRC staff audit documentation of the HCVS In progress (part of 2 above) nitr~gen pneumatic ~stem design including sizing and location.

4. Make available for NRC staff audit the deployment location of the In progress (same as 3 above) portable diesel generators.

5. Make available for NRC staff audit an evaluation of temperature In progress and radiological conditions to ensure that operating personnel can safely access and operate controls and support equipment.

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Enclosure to NL-16-0726 Fourth Six-Month Status Report of Vent Order Implementation Interim Staff Evaluation Open Item Status

6. Make available for NRC staff audit analyses demonstrating that In progress (part of 4 above)

HCVS has the capacity to vent the steam/energy equivalent of one percent of licensed/rated thermal power (unless a lower value is justified), and that the suppression pool and the HCVS together are able to 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.

7. Make available for NRC staff audit the descriptions of local In progress (part of 8 above) 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.

8. Make available for NRC staff audit the final sizing evaluation for In progress (part of 10 above)

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

9. Make available for NRC staff audit documentation that In progress (same as 9 above) demonstrates adequate communication between the remote HCVS operation locations and HCVS decision makers during ELAP and severe accident conditions.

1 0. Provide a description of the final design of the HCVS to address In progress (same as 6 above) hy_drogen detonation and deflagration.

11. Provide a description of the strategies for hydrogen control that In progress (same as 7 above) minimizes the potential for hydrogen gas migration and ingress into the reactor building or other buildings.

12. Make available descriptions of design details that minimize In progress (same as 5 above) unintended cross flow of vented fluids within a unit and between units.

13. Make available for NRC staff audit descriptions of all In progress (same as 8 above) instrumentation and controls (existing and planned) necessary to implement this order including qualification methods.

14. Make available for NRC staff audit documentation of an In progress evaluation verifying the existing containment isolation valves, relied upon for the HCVS, will open under the maximum expected differential pressure during BDBEE and severe accident wetwell venting.

15. Make available for NRC staff audit the control document for Complete (ref. 8)

HCVS out of service time criteria.

Staff Evaluation (Phase 2) Open Item Status TBD NA E-6

Enclosure to NL-16-0726 Fourth Six-Month Status Report of Vent Order Implementation 4

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

5 Additional Information The following additional information supports the Phase 1 and Phase 2 implementation activities:

1. In addition to repowering the main meteorological stack mixing chamber fans as described in the Phase 1 and 2 OIP (Reference 8), HNP will utilize an argon purge into the main stack mixing chamber, (prior to operation of the HCVS vent valves used in response to a EA-13-109 core damage and vessel breach event), as a defense in depth approach to combustible gas control and unintended crossflow mitigation in accordance with method 3 of endorsed white paper HCVS-WP-03.

2. The table on page 23 of the Phase 1 and 2 OIP (Reference 8) shows transmitters for the component for the first 2 items. Refer to the following table to list the respective indicators:

Key Parameter Component Indication Identifier Location HCVS Effluent 1 /2T 48-R650/R 150 MCRIROS temperature HCVS Pneumatic supply 1 P52-R660/R060, MCRIROS pressure 2P52-R630/R030

3. The table on page 26 of the Phase 1 and 2 OIP (Reference 8) shows transmitters for the component for the temperature, pressure, power status and radiation monitor items. Refer to the following table to list the respective indicators:

Key Parameter Component Indication Identifier Location HCVS Effluent 1 /2T 48-R650/R 150 MCRIROS temperature HCVS Pneumatic supply 1 P52-R660/R060, MCRIROS pressure 2P52-R630/R030 HCVS power status*

2R42-R600/R 1 04 MCRIROS and 2R42-R603/R1 05 HCVS effluent radiation 1 /2T 48-R652/R 152 MCRIROS monitor

• The HCVS power status indicator in the MCR will utilize an existing indicator for Station Service Batteries, but a new indicator will be added in the ROS.

4. Additionally, the indicator for "rupture disc pressure" is an indicator that provides information that the rupture disc has been burst by monitoring argon pressure, which will drop significantly when the rupture disc is burst.

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Enclosure to N L 0726 Fourth Six-Month Status Report of Vent Order Implementation 6

References The following references support the updates to the Phase 1 and 2 Overall Integrated Plan (Reference 8) described in this enclosure:

1. SNC Letter, Edwin I. Hatch Phase I Overall Integrated Plan in Response to June 6, 2013 Commission Order Modifying Licenses with Regard to Requirements for Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number EA-13-109), dated June 27, 2014 (ML141788464).

2. NRC Order Number EA-13-1 09, Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions, dated June 6, 2013 (ML13143A321).

3. NRC Endorsement, Hardened Containment Venting System (HCVS) Phase 1 Overall Integrated Plan Template (EA-13-109) Revision 0, dated May1, 2014 (ML14128A219).

4. NRC Letter, Edwin I. Hatch Nuclear Plant Units, 1 and 2 -Interim Staff Evaluation Relating to Overall Integrated Plan in Response to Phase 1 of Order EA-13-1 09 (Severe Accident Capable Hardened Vents) (TAG Nos. MF4479 and MF4480), dated March 25, 2015 (ML14335A137).

5. 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 (ML151138318).

6. 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 1, dated April 2015 (ML15104A118).

7. NRC Endorsement of "Hardened Containment Venting System (HCVS) Phase 1 and 2 Overall Integrated Plan Template," Revision 1, dated September 22, 2015, and Frequently Asked Questions (FAQs) 10, 11, 12, and 13, dated October 8, 2015 (ML15271A148).

8. SNC Letter with Combined Phase 1 and 2 Overall Integrated Plan, Edwin I. Hatch Nuclear Plant-Units 1 and 2 Third Six-Month Status Report of the Implementation of the Commission Order with Regard to Requirements for Reliable Hardened Containment Vents (EA-13-109), dated December 30, 2015 (ML15357A212).

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