CNL-17-138, Plant'S Seventh Six-Month Status Report in Response to the June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions

Plant'S Seventh Six-Month Status Report in Response to the June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions

ML17354A250
Person / Time
Site:	Browns Ferry
Issue date:	12/20/2017
From:	Shea J W Tennessee Valley Authority
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
CNL-17-138, EA-13-109
Download: ML17354A250 (21)

Text

Tennessee Valley Authority, 1101 Market Street, Chattanooga, Tennessee 37402 CNL-17-138 December 20, 2017 10 CFR 50.4 Attn: Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555

-0001 Browns Ferry Nuclear Plant, Units 1, 2, and 3 Renewed Facility Operating License Nos. DPR

-33, DPR-52, and DPR

-68 NRC Docket Nos. 50

-259, 50-260, and 50

-296

Subject:

Tennessee Valley Authority Browns Ferry Nuclear Plant

's Seventh Six-Month Status Report in Response to the June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number EA-13-1 09)

References:

1. NRC Order Number EA 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 (ML13143A321)

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 (ML13304B836)

3. NEI 13-02, "Industry Guidance for Compliance with Order EA 109, BWR Mark I & II Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions," Revision 1, dated April 23, 2015 (ML15113B318)

4. Letter from TVA to NRC, "Tennessee Valley Authority'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 (Order Number EA 109)," dated June 30, 2014 (ML14181B169)

U.S. Nuclear Regulatory Commission CNL-17-138 Page 2 December 20, 2017 5. Letter from TVA to NRC, "Tennessee Valley Authority's Browns Ferry Nuclear Plant First Six

-Month Status Report in Response to the June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number EA 109)," dated December 19, 2014 (ML14353A428)

6. Letter from NRC to TVA, "Browns Ferry Nuclear Plant, Units 1, 2, and 3 - Interim Staff Evaluation Relating to Overall Integrated Plan in Response to Phase 1 of Order EA 109 (Severe Accident Capable Hardened Vents) (TAC Nos. MF4540, MF4541 and MF4542)," dated February 11, 2015 (ML14356A362)

7. 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 29, 2015 (ML15104A118)

8. Letter from TVA to NRC, "Tennessee Valley Authority's Browns Ferry Nuclear Plant Second Six-Month Status Report in Response to the June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number EA 109)," dated June 29, 2015 (ML15181A33

8) 9. Letter from TVA to NRC, "Tennessee Valley Authority's Browns Ferry Nuclear Plant Third Six

-Month Status Report and Phase 1 and Phase 2 Overall Integrated Plan in Response to the 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 29, 2015 (ML15365A554)

10. Letter from TVA to NRC, "Tennessee Valley Authority's Browns Ferry Nuclear Plant Fourth Six

-Month Status Report in Response to the June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number EA 109)," dated June 30, 2016 (ML16182A517)

11. Letter from TVA to NRC, "Tennessee Valley Authority Browns Ferry Nuclear Plant's Fifth Six

-Month Status Report in Response to the June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number EA 109)," dated December 22, 2016 (ML16357A577) 12. Letter from TVA to NRC, "Tennessee Valley Authority Browns Ferry Nuclear Plant's Sixth Six

-Month Status Report in Response to the 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, 2017 (ML17181A333)

U.S. Nuclear Regulatory Commission CNL-17-138 Page 3 December 20, 2017. On June 6, 2013, the Nuclear Regulatory Commission (NRC) issued an Order (Reference

1) to Tennessee Valley Authority (TVA). Reference 1 was immediately effective and directed TVA to install a reliable hardened venting capability for instances of 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. Reference 1 required submission of a Phase 1 and Phase 2 Overall Integrated Plan (OIP) pursuant to Section IV, Condition D for Browns Ferry Nuclear Plant (BFN), Units 1, 2, and 3. References 2 and 7 endorsed industry guidance document Nuclear Energy Institute (NEI) 13-02, Revision 1 (Reference

3) with clarifications and exceptions identified in References 2 and 7. Reference 3 provides direction regarding the content of the Phase 1 and Phase 2 OIPs and includes guidance for combining the OIPs. Reference 4 provided TVA's Phase 1 OIP. The NRC issued its Interim Staff Evaluation relating to the BFN Phase 1 OIP on February 11, 2015 (Reference 6). Reference 1 also requires submission of status reports at six-month intervals following submittal of the OIP. Reference 3 provides direction regarding the content of the status reports. TVA submitted the first six-month status report on December 19, 2014 (Reference

5) and has provided subsequent six-month status reports in References 8 through 12. The purpose of this letter is to provide the combined Phase 1 and Phase 2 OIP six-month status report pursuant to Section IV, Condition D of Reference 1, which delineates progress made in implementing the requirements of Reference 1. The Enclosure provides an update of milestone accomplishments since submittal of the sixth six-month status report, including any changes to the compliance method or schedule.

There are no new regulatory commitments resulting from this submittal.

If you have any question regarding this submittal, please contact Mike Oliver at (256) 729-7874.

I declare under penalty of perjury that the foregoing is true and correct. Executed on the 20th day of December 2017 . . VV. s ice President, Nuclear Regulatory Affairs & Support Services Enclosure cc: See Page 4 U.S. Nuclear Regulatory Commission CNL-17-138 Page 4 December 20, 2017

Enclosure:

Tennessee Valley Authority Browns Ferry Nuclear Plant's Seventh Six-Month Status Report for the Implementation of Order EA 109, "Issuance of Order to Modify Licenses With Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions" cc (w/Enclosure):

NRR Director - NRC Headquarters NRO Director - NRC Headquarters NRC Regional Administrator - Region II NRR Project Manager - Browns Ferry Nuclear Plant NRC Senior Resident Inspector - Browns Ferry Nuclear Plant

CNL-17-138 E-1 ENCLOSURE Tennessee Valley Authority Browns Ferry Nuclear Plant's Seventh S ix-Month Status Report for the Implementation of Order EA-13-109, "Issuance of Order to Modify Licenses With Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions" 1 Introduction Browns Ferry Nuclear Plant (BFN) 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 instances of 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.

Updates of milestone accomplishments will be based on the combined Phase 1 and 2 Overall Integrated Plan dated December 29, 2015. BFN developed an updated and combined Phase 1 and 2 Overall Integrated Plan (Reference 7 in Section 8) documenting: 1. The installation of a Hardened Containment Vent System (HCVS) that provides a reliable hardened venting capability for instances of 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 combined Phase 1 and 2 Overall Integrated Plan and previous update (Reference 12) 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 previous update (Reference 1 2). The status is current as of December 1, 2017. Phase 2 Unit 3 Design Engineering On

-site/Complete 3 Milestone Schedule Status The following provides an update to Part 5 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. These 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.

CNL-17-138 E-2 Milestone Target Completion Date Activity Status Comments {Include date changes in this column} Phase 1 and 2 HCVS Milestone Table Submit Overall Integrated Plan Jun e 2014 Complete Submit 6 Month Updates:

Update 1 December 2014 Complete Update 2 Jun e 2015 Complete Update 3 [Simultaneous with Phase 2 OIP] December 2015 Complete Update 4 Jun e 2016 Complete Update 5 December 2016 Complete Update 6 Jun e 2017 Complete Update 7 December 2017 Complete with this submittal Update 8 June 2018 Not Started Update 9 December 2018 Not Started

CNL-17-138 E-3 Phase 1 Specific Milestones Phase 1 Modifications:

Hold preliminary/conceptual design meeting November 2014 Complete Modifications Evaluation November 2015 Complete Unit 1 Design Engineering On

-site/Complete April 2016 Complete June 2016 Unit 1 Implementation Outage November 2016 Complete Unit 1 Walk Through Demonstration/Functional Test November 2016 Complete Unit 2 Design Engineering On

-site/Complete June 2016 Complete December 2016 Unit 2 Implementation Outage March 2017 Complete Unit 2 Walk Through Demonstration/Functional Test April 2017 Complete Unit 3 Design Engineering On

-site/Complete July 2017 Complete Unit 3 Implementation Outage March 2018 Not Started Unit 3 Walk Through Demonstration/Functional Test April 2018 Not Started Phase 1 Procedure Changes Active Operations Procedure Changes Developed July 2016 Complete Site Specific Maintenance Procedure Developed July 2016 Complete Procedure Changes Active November 2016 Complete Phase 1 Training:

Training Complete September 2016 Complete CNL-17-138 E-4 Phase 1 Completion Unit 1 HCVS Implementation December 2016 Complete Unit 2 HCVS Implementation April 2017 Complete Unit 3 HCVS Implementation March 2018 In-Progress Full Site HCVS Implementation March 2018 Not Started Phase 2 Specific Milestones Phase 2 Modifications:

Hold preliminary/conceptual design meeting January 2017 Complete Modifications Evaluation April 2017 Complete Unit 3 Design Engineering On

-site/Complete May 2017 Complete September 2017 Unit 3 Implementation Outage March 2018 Not Started Unit 3 Walk Through Demonstration/Functional Test March 2018 Not Started Unit 1 Design Engineering On

-site/Complete December 2017 In-Progress May 2018 Unit 1 Implementation Outage October 2018 Not Started Unit 1 Walk Through Demonstration/Functional Test October 2018 Not Started Unit 2 Design Engineering On

-site/Complete May 2018 In-Progress Unit 2 Implementation Outage March 2019 Not Started Unit 2 Walk Through Demonstration/Functional Test March 2019 Not Started Phase 2 Procedure Changes Active Operations Procedure Changes Developed September 2017 In Progress March 2018 Site Specific Maintenance Procedures Developed December 2017 In-Progress March 2018 Procedure Changes Active March 2018 Not Started

CNL-17-138 E-5 Phase 2 Training:

Training Complete December 2017 In-Progress March 2018 Phase 2 Completion Unit 3 HCVS Implementation March 2018 Not Started Unit 1 HCVS Implementation October 2018 Not Started Unit 2 HCVS Implementation March 2019 Not Started Full Site HCVS Implementation March 2019 Not Started Submit Completion Report [60 days after full site compliance]

May 2019 Not Started 4 Changes to Compliance Method The following is a list of changes made to the information provided in the Combined Phase 1 and 2 Overall Integrated Plan (Reference 7). These changes were made to clarify the OIP and provide more specific information because the design process is further along than previously anticipated.

These changes meet the NEI 13

-02 compliance method.

Page 52-54 of 86. Updated Part 5 Milestone Schedule.

Attachment 7. Updated Phase 1 ISE Open Items 8, 9, and 10 to include closure documentation.

Attachment 7. Updated Phase 2 OIP Open Items 1 and 2 to include closure documentation.

Attachment 7. Updated Phase 2 ISE Open Items 1 thru 6 to include closure documentation.

There are no changes to the compliance method as documented in the combined Phase 1 and 2 Overall Integrated Plan (Reference 7). 5 Need for Relief/Relaxation and Basis for the Relief/Relaxation BFN 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 Overall Integrated Plan and Interim 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.

CNL-17-138 E-6 Combined Phase 1 and 2 OIP Open Item Status Phase 1 Open Items

1. Perform an assessment of temperature and radiological conditions to ensure that operating personnel can safely access and operate controls at the Remote Operating Station based on time constraints listed in Attachment 2.

Closed - An assessment was completed and documented in the Design Change Technical Evaluation of DCN 71389 for Unit 1, DCN 71390 for Unit 2, DCN 71391 for Unit 3 , calculation MDQ0000642015000351 "HCVS Operator (Mission) Dose Calculation

," and calculation MDQ0009992014000291 "Temperature Response of the Reactor Building Following an Extended Loss o f AC Power." (This calculation also evaluates the temperature response in the Unit 1/2 and Unit 3 Diesel Building during an ELAP event.) 2. Perform an evaluation for HCVS ability to operate from the MCR and has the ability to be supplied adequate amounts of pneumatic pressure for 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> actions.

Closed - An evaluation was performed and documented in calculation MDQ0000322015000347 R0, HCVS Nitrogen System Sizing Analysis, and DCN 71389. 3. Perform an evaluation for FLEX portable generators and nitrogen cylinders use past 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> actions.

Closed - An evaluation was performed for FLEX portable generators and documented in a White Paper reviewed during FLEX audit and documented in "Browns Ferry Nuclear Plant, Units 1, 2, and 3 - Report for the Onsite Audit Regarding Implementation of Mitigating Strategies and Reliable Spent Fuel Instrumentation Related to Orders EA-12-049 and EA-12-051" (ML15069 A358). A nitrogen cylinder use evaluation was performed and documented in DCN 71389 for Unit 1, DCN 71390 for Unit 2, DCN 71391 for Unit 3 and calculation MDQ0000322015000347 "HCVS Nitrogen System Sizing Analysis

." A combination of installed and dedicated nitrogen cylinder carts will be used to provide a seven

-day supply of nitrogen.

4. Revise 1/2/3

-EOI Appendix

-13 to include venting for loss of DC power. Closed for Unit 1 EOI Appendix-13 , Revision 3 was revised to include venting for loss of DC power.

Closed for Unit 2 EOI Appendix-13 , Revision 9 was revised to include venting for loss of DC power.

Unit 3 - In Progress

5. Perform an evaluation for FLEX portable generators use for post 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> actions in Severe Accident conditions.

Closed - An evaluation for FLEX portable generator use for post 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> actions was performed and documented in Engineering Information Record from AREVA (R06161114360), Projected Dose Rate Contour Map of Shine from the HCVS Vent Line Extending Above Refueling Floor (BFN).

CNL-17-138 E-7 Combined Phase 1 and 2 OIP Open Item Status 6. Electrical load shedding will be performed in 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> of the event.

Closed (Reference 6) - Calculation EDQ0009992013000202 R3, 250V DC Unit Batteries, 1, 2, & 3 Evaluation for the Beyond Design Basis External Event (BDBEE) ELAP, has been issued to determine load shedding impact on the unit batteries.

7. The implementation of the HCVS DCN's will be staged so that there is no effect on the operating units.

Closed (Reference 6) - A conceptual meeting was held in November 2014, and a staging plan was used to separate the existing HWWV from the HCVS.

8. The wetwell vent will be designed to remove 1% of rated thermal power at EPU conditions.

Closed (Reference 6) - The existing wetwell vent (CLTP) and the HCVS (EPU) have been designed for 1 percent of rated thermal power at EPU conditions.

9. Implement the Harris Radio System for communication between the MCR and the ROS.

Closed - A communication system has been implemented that uses hand held radios for communication between the main control room and the remote operating station. (DCN 70852)

Phase 2 Open Items

1. Perform an evaluation for the locations of the SAWA equipment and controls, as well as ingress and egress paths for the expected Severe Accident conditions (temperature, humidity, radiation) for the sustained operating period. Closed - Equipment and Controls Plant instrumentation for SAWM that is qualified to NRC Regulatory Guide (RG) 1.97 or equivalent is considered qualified for the sustained operating period without further evaluation. The following plant instruments are qualified to RG 1.97: Drywell (DW) Pressure 1,2,3

-PI-64-67B Suppression Pool Level 1,2,3

-LI-64-159A Passive components that do not need to change state after initially establishing SAWA flow do not require evaluation beyond the first 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />, at which time they are expected to be installed and ready for use to support SAWA/SAWM.

The following additional equipment performing an active SAWA/SAWM function is considered:

SAWA/SAWM flow instrument.

SAWA/SAWM pump FLEX generator SAWA throttle valve These components will be used at a remote location (outside reactor building) and have been evaluated for the environmental conditions applicable at those locations.

Ingress and Egress A quantitative evaluation of expected dose rates

,

CNL-17-138 E-8 Combined Phase 1 and 2 OIP Open Item Status AREVA document 51-9262174-003 , "Projected Dose Rate Contour Map of Shine from the HCVS Vent Line Extending Above Refueling Floor (BFNP)

," has been performed per NEI HCVS-WP-02, "Sequences for HCVS Design and Method for Determining Radiological Dose from HCVS Piping,"

and found the dose rates at deployment locations including ingress/egress paths are acceptable.

2. Perform an hydraulic evaluation to ensure flow adequacy can be met for all 3 units using 1 FLEX pump to support SAWA flow requirement Closed - Hydraulic Analysis calculation MDN0003602014000233 was revised to include a bounding case that concluded that a single FLEX pump (with booster pump) can provide 500 gpm to Unit 1 RPV, 500 gpm to Unit 2 RPV, and 500 gpm to Unit 3 RPV (each at RPV pressure of 106 psig) in response to a SAWA event.

Phase 1 Interim Staff Evaluation Open Item Status 1. Make available for NRC staff audit an evaluation of temperature and radiological conditions to ensure that operating personnel can safely access and operate controls and support equipment.

Closed - An assessment was completed and documented in the Design Change Technical Evaluation of DCN 71389 for Unit 1, DCN 71390 for Unit 2, and DCN 71391 for Unit 3, calculation MDQ0000642015000351 "HCVS Operator (Mission)

Dose Calculation" , and calculation MDQ0009992014000291 "Temperature Response o f the Reactor Building Following an Extended Loss o f AC Power." (This calculation also evaluates the temperature response in the Unit 1/2 and Unit 3 Diesel Building during an ELAP event.) Documentation is available for audit.

2. Make available for NRC audit documentation that procedure 1/2/3-EOI Appendix

-13 has been revised to include venting for loss of dc power.

Closed for Unit 1 EOI Appendix-13 , Revision 3 was revised to include venting for loss of DC power.

Closed for Unit 2 EOI Appendix-13, Revision 9 was revised to include venting for loss of DC power.

Documentation is available for audit.

Unit 3 - In Progress

CNL-17-138 E-9 Phase 1 Interim Staff Evaluation Open Item Status 3. Make available for NRC staff audit documentation demonstrating that all load sheds will be accomplished within one hour of event initiation and will occur in an area not impacted by a possible radiological event. Closed - Calculation EDQ0009992013000202 R3, 250V DC Unit Batteries, 1, 2, & 3 Evaluation for the Beyond Design Basis External Event (BDBEE) Extended Loss of AC Power (ELAP), has been issued to determine load shedding impact on the unit batteries, and is available for audit. 4. Make available for NRC staff audit documentation that demonstrates that operating units that have not implemented the order will be able to vent through the existing vent system unaffected by the implementation of HCVS on other units. Closed - A conceptual meeting was held in November 2014, and a staging plan was used to separate the existing HWWV from the HCVS. Documentation is available for audit.

5. Make available for NRC staff audit analyses demonstrating that 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.

Closed - The existing wetwell vent (CLTP) and the HCVS (EPU) have been designed for 1 percent of rated thermal power at EPU conditions.

Analyses are available for audit.

6. Make available for NRC staff audit documentation that demonstrates adequate communication between the remote HCVS operation locations and HCVS decision makers during ELAP and severe accident conditions.

Closed - A communication system has been implemented that uses hand held radios for communication between the main control room and the remote operating station (DCN 70852). Documentation is available for audit.

CNL-17-138 E-10 Phase 1 Interim Staff Evaluation Open Item Status 7. Make available for NRC staff audit documentation of an 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.

Closed - An evaluation was performed and concluded that the containment isolation valves will open under the maximum expected differential pressure and is documented in FLOWSERVE Report RAL

-70181, Design Review Report of Size 14 Class 150 Wafer Butterfly Valve with Pneumatic Actuator R1.

Documentation is available for audit. 8. Make available for NRC staff audit documentation of a seismic qualification evaluation of HCVS components.

Closed - All electrical and I&C components were procured as seismically qualified or as Seismic Class I to ensure their functionality following a seismic event. Seismic qualification reports of HCVS components are available for audit.

9. Make available for NRC staff audit descriptions of all instrumentation and controls (existing and planned) necessary to implement this order including qualification methods.

Closed -Instrumentation and controls necessary to implement this order including equipment description, location, and qualifications are available for audit.

10. Make available for NRC staff audit the descriptions of local conditions (temperature, radiation and humidity) anticipated during ELAP and severe accident for the components (valves, instrumentation, sensors, transmitters, indicators, electronics, control devices, and etc.) required for HCVS venting including confirmation that the components are capable of performing their functions during ELAP and severe accident conditions.

Closed - Descriptions of local conditions (temperature, radiation and humidity) anticipated during ELAP and severe accident for the components (valves, instrumentation, sensors, transmitters, indicators, electronics, control devices, and etc.) required for HCVS venting including confirmation that the components are capable of performing their functions during ELAP and severe accident conditions are available for audit.

CNL-17-138 E-11 Phase 1 Interim Staff Evaluation Open Item Status 11. Make available for NRC staff audit the final sizing evaluation for HCVS batteries/battery charger including incorporation into FLEX DG loading calculation.

Closed - HCVS batteries/battery charger final sizing evaluation was performed and documented in the Design Change Technical Evaluation of DCN 71389 for Unit 1, DCN 71390 for Unit 2 and DCN 71391 for Unit 3. There is no incorporation of the HCVS battery/battery charger required into the FLEX DG loading calculation due to no plans or requirements to recharge the HCVS battery after depletion. The HCVS electrical loads will be aligned back to their normal power supply which is the Unit Battery. The recharging of the Unit Battery is incorporated into the FLEX DG loading calculations. Calculation EDQ0003602014000281 R3 "Electrical Evaluation for Portable Power Supply for Unit Battery Chargers" and calculation EDQ0003602015000325 R1 "Electrical Evaluation for 4KV Spare FLEX Turbine Generators." Documentation is available for audit.

12. Make available for NRC staff audit documentation of the HCVS nitrogen pneumatic system design including sizing and location.

Closed - Evaluation completed and documented in calculation MDQ0000322015000347 R1, HCVS Nitrogen System Sizing Analysis, DCN 71389 for Unit 1, DCN 71390 for Unit 2 , and DCN 71391 for Unit 3. Documentation is available for audit.

13. Make available for NRC staff audit the seismic and tornado missile final design criteria for the HCVS stack. Closed - Tornado and seismic missile criteria are located in System 64A Design Criteria Document (DCD). As part of DCN 71389 for Unit 1, DCN 71390 for Unit 2, and DCN 71391 for Unit 3 a markup reflecting these changes has been generated and will be incorporated in the next revision of the DCD per TVA process.

Documentation is available for audit.

14. Provide a description of the final design of the HCVS to address hydrogen detonation and deflagration.

Closed - The final design of HCVS at BFN to address hydrogen detonation and deflagration is the installation of a check valve near the vent discharge release point. A description of this design is contained in the Technical Evaluation for DCN 71389 for Unit 1, DCN 71390 for Unit 2, and DCN 71391 for Unit 3.

Documentation is available for audit.

CNL-17-138 E-12 Phase 1 Interim Staff Evaluation Open Item Status 15. Provide a description of the strategies for hydrogen control that minimizes the potential for hydrogen gas migration and ingress into the reactor building or other buildings.

Closed -The HCVS provides a direct vent path from the wetwell to an exhaust point above the Reactor Building Roof in accordance with NEI 13-02 section 4.1.5. This is a leak tight system with no boundary valves outside the PCIV's that would allow hydrogen gas migration and ingress into the Reactor Building or other buildings. Per NEI 13

-02 FAQ-04 an effluent release velocity of 8000 fpm will assure that the effluent plume will not be entrained into the roof recirculation zone of a given building. A description of this design is contained in the Technical Evaluation for DCN 71389 for Unit 1, DCN 71390 for Unit 2, and DCN 71391 for Unit

3. Documentation is available for audit. 16. Provide design details that minimize unintended cross flow of vented fluids within a unit and between units on the site.

Closed -The BFN design includes a separate HCVS stack for each unit as well as meeting the testing criteria and valve requirements for PCIVs, control and boundary valves. A description of this design is contained in the Technical Evaluation for DCN 71389 for Unit 1, DCN 71390 for Unit 2, and DCN 71391 for Unit 3. Documentation is available for audit. Phase 2 Interim Staff Evaluation Open Item Status 1. Licensee to perform a hydraulic evaluation to ensure flow adequacy can be met for all 3 units using 1 FLEX pump to support SAWA flow requirement.

Closed - Hydraulic Analysis calculation MDN0003602014000233 was revised to include a bounding case that concluded that a single FLEX pump (with booster pump) can provide 500 gpm to Unit 1 RPV, 500 gpm to Unit 2 RPV, and 500 gpm to Unit 3 RPV (each at RPV pressure of 106 psig) in response to a SAWA event.

CNL-17-138 E-13 Phase 2 Interim Staff Evaluation Open Item Status 2. Licensee to evaluate the SAWA equipment and controls, as well as the ingress and egress paths for the expected severe accident conditions (temperature, humidity, radiation) for the sustained operating period.

Closed - Equipment and Controls Plant instrumentation for SAWM that is qualified to

RG 1.97 or equivalent is considered qualified for the sustained operating period without further evaluation.

The following plant instruments are qualified to RG 1.97: DW Pressure 1,2,3

-PI-64-67B Suppression Pool Level 1,2,3

-LI-64-159A Passive components that do not need to change state after initially establishing SAWA flow do not require evaluation beyond the first 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />, at which time they are expected to be installed and ready for use to support SAWA/SAWM.

The following additional equipment performing an active SAWA/SAWM function is considered:

SAWA/SAWM flow instrument.

SAWA/SAWM pump FLEX generator SAWA throttle valve These components will be used at a remote location (outside reactor building) and have been evaluated for the environmental conditions applicable at those locations.

Ingress and Egress A quantitative evaluation of expected dose rates, AREVA document 51-9262174-003, "Projected Dose Rate Contour Map of Shine from the HCVS Vent Line Extending Above Refueling Floor (BFNP)

," has been performed per NEI HCVS-WP-02 , "Sequences for HCVS Design and Method for Determining Radiological Dose from HCVS Piping,"

and found the dose rates at deployment locations including ingress/egress paths are acceptable.

CNL-17-138 E-14 Phase 2 Interim Staff Evaluation Open Item Status 3. Licensee to demonstrate how SAWA flow is capable to perform its intended function for the sustained operating period under the expected temperature and radiological conditions.

Closed - Equipment and Controls Plant instrumentation for SAWA that is qualified to RG 1.97 or equivalent is considered qualified for the sustained operating period without further evaluation.

The following plant instruments are qualified to RG 1.97: DW Pressure 1,2,3

-PI-64-67B Suppression Pool Level 1,2,3

-LI-64-159A Passive components that do not need to change state after initially establishing SAWA flow do not require

evaluation beyond the first 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />, at which time they are expected to be installed and ready for use to support SAWA/SAWM.

The following additional equipment performing an active SAWA/SAWM function is considered for temperature and radiation effects:

SAWA/SAWM flow instrument FLEX/SAWA pump FLEX generator SAWA throttle valve Temperature The location of SAWA equipment and controls that are the same or similar as FLEX will be bounded by the FLEX evaluations for temperature.

Radiation A quantitative evaluation of expected dose rates (AREVA document 51-9262174-003 "Projected Dose Rate Contour Map of Shine from the HCVS Vent Line Extending Above Refueling Floor (BFNP))"

has been performed per NEI HCVS-WP-02 , "Sequences for HCVS Design and Method for Determining Radiological Dose from HCVS Piping

," and found the dose rates at deployment locations are acceptable.

CNL-17-138 E-15 Phase 2 Interim Staff Evaluation Open Item Status 4. Licensee to demonstrate that containment failure as a result of overpressure can be prevented without a drywell vent during severe accident conditions.

The wetwell vent has been designed and installed (Units 1 and 2 only) to meet NEI 13

-02 Rev 1 guidance which will ensure 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. Browns Ferry Nuclear Plant will follow the guidance (flow rate and timing) for SAWA/SAWM described in BWROG

-TP-15-008 and BWROG-TP-15-011. The wetwell vent will be opened prior to exceeding the primary containment pressure limit value of 62 PSIG. Therefore, containment over pressurization is prevented without the need for a drywell vent.

5. Licensee to demonstrate how the plant is bounded by the reference plant analysis that shows the SAWM strategy is successful in making it unlikely that a drywell vent is needed. Closed - Figure 2.1.C, from the combined Phase 1 and 2 OIP, compare s the reference plant parameters to the plant specific parameters.

Reference Plant Browns Ferry Nuclear Plant Torus freeboard volume is 525,000 gallons Torus freeboard volume is

757 , 544 gallons SAWA flow is

500 GPM at 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> followed by

100 GPM from 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> to 168 hours0.00194 days <br />0.0467 hours <br />2.777778e-4 weeks <br />6.3924e-5 months <br /> SAWA flow is

500 GPM at 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> followed by 100 GPM from 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> to 168 hours0.00194 days <br />0.0467 hours <br />2.777778e-4 weeks <br />6.3924e-5 months <br /> The above parameters for Browns Ferry Nuclear Plant compared to the reference plant that determine success of the SAWM strategy demonstrate that the reference plant values are bounding. Therefore, the SAWM strategy implemented at Browns Ferry Nuclear Plant makes it unlikely that a DW vent is needed to prevent containment overpressure related failure.

CNL-17-138 E-16 Phase 2 Interim Staff Evaluation Open Item Status 6. Licensee to demonstrate that there is adequate communication between the MCR and the operator at the FLEX pump during severe accident conditions.

Closed - Browns Ferry Nuclear Plant utilizes the Harris Radio System to communicate between the MCR and the operator at the FLEX pump. This communication method is the same as described for Order EA-12-049. These items will be powered and remain powered using the same methods as evaluated under EA 049 and continued for the period of sustained operation.

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

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

1. Letter from TVA to NRC, "Tennessee Valley Authority'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 (Order Number EA 109)," dated June 30, 2014 (ML14181B169)

2. NRC Order Number EA 109, "Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions ," dated June 6, 2013 (ML13143A321)

3. NEI 13-02, "Industry Guidance for Compliance with NRC Order EA 109, 'To Modify Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions," Revision 1, dated April 2015 (ML15113B318)

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 (ML13304B836).

5. NRC Endorsement of industry "Hardened Containment Venting System (HCVS) Phase 1 Overall Integrated Plan Template (EA 109) Rev 0

," dated May 14, 2014 (ML14128A219).

6. JLD-ISG-2012-01, "Compliance with Order EA 049, Mitigation Strategies for Beyond-Design-Basis External Events," dated August 29, 2012 (ML12229A174)

7. Letter from TVA to NRC, "Tennessee Valley Authority's Browns Ferry Nuclear Plant Third Six-Month Status Report and Phase 1 and Phase 2 Overall Integrated Plan in Response to the June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number EA 109)," dated December 29, 2015 (ML15365A554)

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 (ML15104A118).

CNL-17-138 E-17 9. Letter from TVA to NRC "Tennessee Valley Authority's Browns Ferry Nuclear Plant Fourth Six

-Month Status Report in Response to the June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number EA 109)," dated June 30, 2016 (ML16182A517)

10. Letter from TVA to NRC "Tennessee Valley Authority Browns Ferry Nuclear Plant's Fifth Six-Month Status Report in Response to the June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number EA 109)," dated December 22, 2016 (ML16357A577)

11. Letter from NRC to TVA, "Browns Ferry Nuclear Plant, Units 1, 2 and 3 - Interim Staff Evaluation Relating to Overall Integrated Plan in Response to Phase 2 of Order EA-13-109 (Severe Accident Capable Hardened Vents) (C AC Nos. MF4540, MF4541 and MF4542)," dated September 6, 2016 (ML16244A762)

12. Letter from TVA to NRC, "Tennessee Valley Authority Browns Ferry Nuclear Plant's Sixth Six-Month Status Report in Response to the 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, 2017 (ML17181A333)