CNL-15-132, 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

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

ML15181A338
Person / Time
Site:	Browns Ferry
Issue date:	06/29/2014
From:	James Shea Tennessee Valley Authority
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
CNL-15-132, EA-13-109, TAC MF4540, TAC MF4541, TAC MF4542
Download: ML15181A338 (71)

Text

Tennessee Valley Authority, 1101 Market Street, Chattanooga, Tennessee 37402 CNL-15-132 June 29, 2015 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 Authoritys 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-13-109)

References:

1. NRC Order Number EA-13-109, Issuance of Order Modifying 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-13-109, 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 Authoritys 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-13-109), dated June 30, 2014 (ML14181B169)

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-13-109), 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

U.S. Nuclear Regulatory Commission CNL-15-132 Page 3 June 29, 2015

Enclosures:

1. Tennessee Valley Authority Browns Ferry Nuclear Plants Second Six-Month Status Report for the Implementation of Order EA-13-109, Issuance of Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions

2. Revision 1 of Tennessee Valley Authoritys 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-13-109) cc (w/Enclosure):

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

CNL-15-132 Page E1-1 of 9 ENCLOSURE 1 TENNESSEE VALLEY AUTHORITY BROWNS FERRY NUCLEAR PLANTS SECOND SIX-MONTH STATUS REPORT FOR THE IMPLEMENTATION OF ORDER EA-13-109, ISSUANCE OF ORDER MODIFYING 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 (OIP) (Reference 5),

documenting the planned 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 1. This enclosure provides an update of milestone accomplishments since submittal of the first six-month status update (Reference 6), including any changes to the compliance method or schedule.

2 Milestone Accomplishments The following milestone has been completed since submittal of the first six-month status update (Reference 6) and is current as of June 1, 2015.

Commenced detailed design for Unit 1 Wetwell HCVS.

3 Milestone Schedule Status The following provides an update to the Milestone Schedule of the OIP. This section provides the activity status of each item and the expected completion date, noting any change. The dates are planning dates subject to change as design and implementation details are developed.

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

CNL-15-132 Page E1-2 of 9 Activity Status updates are shown in bold type.

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

Update 1 Dec 2014 Complete Update 2 Jun 2015 Complete with this submittal Update 3 [Simultaneous with Phase 2 OIP]

Dec 2015 Not Started Update 4 Jun 2016 Not Started Update 5 Dec 2016 Not Started Update 6 Jun 2017 Not Started Update 7 Dec 2017 Not Started Modifications:

Hold preliminary/conceptual design meeting Nov 2014 Complete Unit 1 Design Engineering On-site/Complete Jan 2016 In Progress Unit 1 Implementation Outage Nov 2016 Not Started Unit 1 Walk Through Demonstration/Functional Test Nov 2016 Not Started Unit 2 Design Engineering On-site/Complete Jun 2016 Not Started Unit 2 Walk Through Demonstration/Functional Test Apr 2017 Not Started Unit 2 Implementation Outage Mar 2017 Not Started Unit 3 Design Engineering On-site/Complete Jul 2017 Not Started Unit 3 Walk Through Demonstration/Functional Test Apr 2018 Not Started Unit 3 Implementation Outage Mar 2018 Not Started Procedure Changes Active Operations Procedure Changes Developed Jul 2016 Not Started Site Specific Maintenance Procedure Developed Jul 2016 Not Started Procedure Changes Active Nov 2016 Not Started

CNL-15-132 Page E1-3 of 9 Milestone Target Completion Date Activity Status Revised Target Completion Date Phase 1 HCVS Milestone Table Training:

Training Complete Sep 2016 Not Started Completion Unit 1 HCVS Implementation Dec 2016 Not Started Unit 2 HCVS Implementation Apr 2017 Not Started Unit 3 HCVS Implementation Mar 2018 Not Started Full Site HCVS Implementation Mar 2018 Not Started Submit Completion Report [60 days after full site compliance]

Jun 2018 Not Started 4

Changes to Compliance Method The following is a list of changes made to the information provided in the OIP (Reference 5) and previous six month update (Reference 6). These changes meet the NEI 13-02 compliance method. These changes were performed to clarify the OIP and provide more accurate information as the design process has matured. Based on the number and extent of revisions made to the OIP and to provide clarity for the BFN approach, a clean revised version (Revision 1) of the OIP is provided as Enclosure 2 to this letter.

• Throughout the OIP removed the word system following HCVS due to it being redundant.

• Page 3 of 59, removed Temperature from second bullet due to this is not a required parameter.

• Corrected Page 4 of 59, to remove the statement that HCVS equipment will demonstrate functionality to meet the Design Basis Earthquake due to not being applicable in this location of the OIP.

• Page 8 of 59, clarified that operation of FCV-64-221 and 222 is by operation of manual valves.

• Page 8 of 59, removed the following statement Piping, valves and penetrations for the Wetwell may be used for Wetwell vent and purge prior to or following refueling outages or for pressure control during normal plant operation due to this is not an accurate statement for BFN.

• Page 9 of 59, first bullet removed the words accumulators and portable due to planned BFN design does not use accumulators and will have installed nitrogen storage bottles.

• Page 9 of 59, first bullet removed the words to extend past and added for to provide accurate description of the planned BFN design and also clarified the time frames.

• Page 9 of 59, second bullet was clarified to provide an accurate description of the planned BFN design.

CNL-15-132 Page E1-4 of 9

• Page 9 of 59, third bullet was clarified to provide an accurate description of the planned BFN design.

• Pages 9 and 10 of 59, Section 1 statement was clarified to provide an accurate description of the planned BFN design.

• Page 10 of 59, Section 2 statement was corrected to state the transfer switches will be located in the Diesel Generator Buildings.

• Page 10 of 59, Section 3, was clarified to provide an accurate description of the planned BFN design.

• Page 10 of 59, Section 4 statement was clarified to provide an accurate description of the planned BFN design.

• Page 12 of 59 first paragraph under Vent Size and Basis removed the or greater to accurately state the planned BFN design.

• Page 13 of 59, second paragraph under Vent Path and Discharge clarified that the HCVS pipe will exit the Reactor Building wall through an existing valve pit and TVAs plan for missile protection of HCVS piping located on refuel floor and roof in accordance with the BFN Design Basis. Also deleted the eighth paragraph under Vent Path and Discharge due to it not being needed.

• Page 15 of 59, clarified discussion on missile protection to state the specific elevations that will be protected and to reference 33 only.

• Page 15 of 59, second paragraph under Power and Pneumatic Supply Sources changed to provide an accurate description of the planned BFN design.

• Page 15 of 59, Number 1 under Power and Pneumatic Supply Sources deleted discussion of Anticipatory Venting due to not being applicable under this heading. Also changed the number of valve operating cycles to reflect the planned design.

• Page 16 of 59, Number 6 under Power and Pneumatic Supply Sources was deleted due to staging location of the additional nitrogen bottles has not been determined at this phase of the design.

• Page 16 of 59, under Location of Control Panels the first paragraph was clarified to state that while operation of the HCVS could be performed from both the control room and ROS, monitoring is from MCR only.

• Pages 16 and 17 of 59, under Location of Control Panels the second paragraph was clarified to state that Evaluations will be performed for the Diesel Generator Buildings to verify area temperatures are acceptable for the ROS.

• Page 17 of 59, clarified that the BFN HCVS planned design is to prevent detonation.

• Page 18 of 59, under Hydrogen deleted placing a rupture disc and added the use of a check valve and blow off cap to provide an accurate description of the planned BFN design.

• Page 18 of 59, under Unintended Cross Flow of Vented Fluids, fourth sentence was removed due to HCVS isolation valves are not shared with the Containment Purge System.

• Page 19 of 59, under Unintended Cross Flow of Vented Fluids, removed the following sentence: The minimum distance between each units release point will be 150 feet. Based on the prevailing wind direction and velocity of the plume, the discharge of the effluent should not have any effect on the adjacent units HCVS due to separation criteria is based on analysis not distance.

• Page 19 of 59, under Unintended Cross Flow of Vented Fluids removed the last sentence due to additional testing will be required to periodically determine operability.

CNL-15-132 Page E1-5 of 9

• Page 19 of 59, under Prevention of Inadvertent Actuation, second bullet was removed due to no interlocks exist nor planned.

• Page 20 of 59, under Component Qualifications revised the third sentence of the first paragraph to provide an accurate description of the planned BFN design.

• Page 22 of 59, deleted discussion on Thermal Conditions and locations due to it not being applicable to the purpose of this section Monitoring of HCVS.

• Page 23 of 59, revised qualification requirements of instruments that are purchased as commercial-grade equipment to accurately reflect the requirements for BFN.

• Page 24 of 59, section i under System Control, revised the paragraph to accurately reflect the planned BFN design due to throttling of valves and jumpers are not required.

• Page 25 of 59, first paragraph under Greater Than 24 Hour Coping Detail was revised to provide an accurate description of the planned BFN design.

• Pages 25 and 26 of 59, Update current status of DCNs and provided corrected DCN numbers, item 5 and 6 added DCN number.

• Page 26 of 59, under EA-13-109 Modifications clarified that the transfer switch will be powered from the Unit Battery after the first 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. Also included a discussion of the valve operating motive force nitrogen supply.

• Page 27 of 59, under Key Venting Parameters changed to accurately describe the planned BFN design.

• Page 30 of 59, text under BDBEE Venting was revised to accurately describe the planned BFN design.

• Page 33 of 59, changed to state that Part 3 will be completed with the EA-13-109 Order, Phase 2 OIP submittal by December 31, 2015.

• Page 35 of 59, text under Procedures changed where provisions for out of service requirements will be documented from 1, 2, 3-EOI-2 to OPDP-8.

• Pages 38 and 39 of 59, Updated Table 4-1 Testing and Inspection Requirements to match Revision 1 of NEI 13-02.

• Pages 45 and 46 of 59, Updated Figures 2 and 3 to provide accurate description of the planned BFN design.

• Attachment 5, added Reference 37, TVA OPDP-8, Operability Determination Process and Limiting Conditions for Operation Tracking, Revision 18 and Reference 38, NRC letter 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-13-109 (Severe Accident Capable Hardened Vents) (TAC Nos. MF4540, MF4541 and MF4542), dated February 11, 2015.

• Attachment 7, Updated current status of OIP Open items and added NRC ISE Open Items and status.

Currently, there are no changes to the compliance method that would be considered an alternative to NEI 13-02.

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.

CNL-15-132 Page E1-6 of 9 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 OIP or the Interim Staff Evaluation (ISE) and the status of each item.

Overall Integrated Plan Phase 1 Open Item Status 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.

Open 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.

Open 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.

Open 4 Revise 1/2/3-EOI Appendix 13 to include venting for loss of DC power.

Open 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.

Open 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 - Calculation EDQ0009992013000202 Rev 1 has been issued to determine load shedding impact on the unit batteries.

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

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

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

Revised - A communication system will be used that uses hand held radios for communication between the main control room and the remote operating station.

CNL-15-132 Page E1-7 of 9 Interim Staff Evaluation Phase 1 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.

In Progress 2

Make available for NRC audit documentation that procedure 1/2/3-EOI Appendix 13 to has been revised to include venting for loss of dc power.

In Progress 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 Rev 1 has been issued to determine load shedding impact on the unit batteries.

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.

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) has been designed for 1% of rated thermal power at EPU conditions.

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.

In Progress 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.

In Progress 8

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

In Progress 9

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

In Progress

CNL-15-132 Page E1-8 of 9 Interim Staff Evaluation Phase 1 Open Item (Continued)

Status 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.

In Progress 11 Make available for NRC staff audit the final sizing evaluation for HCVS batteries/battery charger including incorporation into FLEX DG loading calculation.

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

In Progress 13 Make available for NRC staff audit the seismic and tornado missile final design criteria for the HCVS stack.

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

In Progress 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.

In Progress 16 Provide design details that minimize unintended cross flow of vented fluids within a unit and between units on the site.

In Progress 7

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

CNL-15-132 Page E1-9 of 9 8

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

1. NRC Order Number EA-13-109, Issuance of Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions, dated June 6, 2013 (ML13143A321)

2. 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 (ML15113B318)

3. 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 2013 (ML13304B836)

4. Letter from NRC to NEI, Endorsement of Industry Hardened Containment Venting System (HCVS) Phase 1 Overall Integrated Plan Template (EA-13-109) Rev 0, dated May 14, 2014 (ML14128A219)

5. Letter from TVA to NRC, Tennessee Valley Authoritys 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-13-109), dated June 30, 2014 (ML14181B169)

6. 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-13-109), dated December 19, 2014 (ML14353A428)

7. 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-13-109 (Severe Accident Capable Hardened Vents) (TAC Nos. MF4540, MF4541 and MF4542),

dated February 11, 2015 (ML14356A362)

8. NRC Interim Staff Guidance JLD-ISG-2015-01, Compliance with Phase 2 of Order EA 109, Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation under Severe Accident Conditions, Revision 0, dated April 2015 (ML15104A118)

Revision 1 of Tennessee Valley Authoritys 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-13-109)

Table of Contents:

Part 1: General Integrated Plan Elements and Assumptions Part 2: Boundary Conditions for Wet Well Vent Part 3: Boundary Conditions for Dry Well Vent Part 4: Programmatic Controls, Training, Drills and Maintenance Part 5: Implementation Schedule Milestones :

HCVS Portable Equipment :

Sequence of Events :

Conceptual Sketches :

Failure Evaluation Table :

References :

Changes/Updates to this Overall Integrated Implementation Plan :

List of Overall Integrated Plan and Interim Staff Evaluation (ISE) Open Items Phase I OIP Page E2-1 of 59 Revision 1 Revision 1 of Tennessee Valley Authoritys 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-13-109)

Introduction In 1989, the NRC issued Generic Letter 89-16, Installation of a Hardened Wetwell Vent, to all licensees of BWRs with Mark I containments to encourage licensees to voluntarily install a hardened wetwell vent. In response, licensees installed a hardened vent pipe from the wetwell to some point outside the secondary containment envelope (usually outside the reactor building).

Some licensees also installed a hardened vent branch line from the drywell.

On March 19, 2013, the Nuclear Regulatory Commission (NRC) Commissioners directed the staff per Staff Requirements Memorandum (SRM) for SECY-12-0157 to require licensees with Mark I and Mark II containments to "upgrade or replace the reliable hardened vents required by Order EA-12-050 with a containment venting system designed and installed to remain functional during severe accident conditions." In response, the NRC issued Order EA-13-109, Issuance of Order to Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accidents, June 6, 2013. The Order (EA-13-109) requires that licensees of BWR facilities with Mark I and Mark II containment designs ensure that these facilities have a reliable hardened vent to remove decay heat from the containment, and maintain control of containment pressure within acceptable limits following events that result in the 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).

The Order requirements are applied in a phased approach where:

Phase 1 involves upgrading the venting capabilities from the containment wetwell to provide reliable, severe accident capable hardened vents to assist in preventing core damage and, if necessary, to provide venting capability during severe accident conditions.

(Completed no later than startup from the second refueling outage that begins after June 30, 2014, or June 30, 2018, whichever comes first.)

Phase 2 involves providing additional protections for severe accident conditions through installation of a reliable, severe accident capable drywell vent system or the development of a reliable containment venting strategy that makes it unlikely that a licensee would need to vent from the containment drywell during severe accident conditions. (Completed no later than startup from the first refueling outage that begins after June 30, 2017, or June 30, 2019, whichever comes first.)

The NRC provided an acceptable approach for complying with Phase 1 of Order EA-13-109 through Interim Staff Guidance (JLD-ISG-2013-02) issued in November 2013. The ISG endorses the compliance approach presented in NEI 13-02 Revision 0, Compliance with Order EA-13-109, Severe Accident Reliable Hardened Containment Vents, with clarifications.

Except in those cases in which a licensee proposes an acceptable alternative method for complying with Order EA-13-109, the NRC staff will use the methods described in this ISG (NEI 13-02) to evaluate licensee compliance as presented in submittals required in Order EA-13-109.

Phase I OIP Page E2-2 of 59 Revision 1 Revision 1 of Tennessee Valley Authoritys 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-13-109)

The Order also requires submittal of an overall integrated plan (OIP) that will provide a description of how the requirements of the Order will be achieved. This document provides the Tennessee Valley Authoritys (TVAs) OIP for the Browns Ferry Nuclear Plants (BFNs) compliance with Order EA-13-109 using the methods described in NEI 13-02 and endorsed by NRC JLD-ISG-2013-02. Six month progress reports will be provided consistent with the requirements of Order EA-13-109.

The Plant venting actions for the EA-13-109 severe accident capable venting scenario can be summarized by the following:

The hardened containment vent system (HCVS) will be initiated via manual action from the Main Control Room (MCR) or Remote Operating Station (ROS) at the appropriate time based on procedural guidance in response to plant conditions from observed or derived symptoms.

The vent will utilize containment parameters of pressure and level from the MCR instrumentation to monitor effectiveness of the venting actions.

Vent operation will be monitored by HCVS valve position, temperature, pressure, and effluent radiation levels.

The HCVS motive force will be monitored and have the capacity to operate for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> with installed equipment. Motive force will be replenished by use of portable equipment once the installed motive force is exhausted.

Venting actions will be capable of being maintained for a sustained period of up to 7 days or a shorter time if justified.

Phase I OIP Page E2-3 of 59 Revision 1 Revision 1 of Tennessee Valley Authoritys 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-13-109)

Part 1: General Integrated Plan Elements and Assumptions Extent to which the guidance, JLD-ISG-2013-02 and NEI 13-02, are being followed. Identify any deviations.

Include a description of any alternatives to the guidance. A technical justification and basis for the alternative needs to be provided. This will likely require a pre-meeting with the NRC to review the alternative.

Ref: JLD-ISG-2013-02 Compliance will be attained for BFN with no known deviations to the guidelines in JLD-ISG-2013-02 and NEI 13-02 for each phase as follows:

Phase 1 (wetwell): by the startup from the second refueling outage that begins after June 30, 2014, or June 30, 2018, whichever comes first. Currently scheduled for design and implementation as noted in Part 5 of this OIP.

Phase 2: The Phase 2 portion of the order is in the early strategy stage and future updates will provide additional information when available.

The BFN is a three unit site that will have the capacity to have each unit operate at Extended Power Uprate (3952 MWt). The design and implementation of the HCVS for each unit will have independent operation and be fully compliant with NRC Order EA-13-109.

If deviations are identified at a later date, then the deviations will be communicated in a future 6 month update following identification.

State Applicable Extreme External Hazard from NEI 12-06, Section 4.0-9.0 List resultant determination of screened in hazards from the EA-12-049 Compliance.

Ref: NEI 13-02 Section 5.2.3 and D.1.2 The following extreme external hazards screen-in for BFN:

Seismic, External Flooding, High Wind, Extreme High Temperature, Extreme Cold.

The following extreme external hazards screen out for BFN:

None Key Site assumptions to implement NEI 13-02 HCVS Actions.

Provide key assumptions associated with implementation of HCVS Phase 1 Actions Ref: NEI 13-02 Section 1 Mark I/II Generic HCVS Related Assumptions:

Applicable EA-12-049 assumptions:

049-1.

Assumed initial plant conditions are as identified in NEI 12-06 section 3.2.1.2 items 1 and 2 Phase I OIP Page E2-4 of 59 Revision 1 Revision 1 of Tennessee Valley Authoritys 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-13-109)

Part 1: General Integrated Plan Elements and Assumptions 049-2.

Assumed initial conditions are as identified in NEI 12-06 section 3.2.1.3 items 1, 2, 4, 5, 6 and 8 049-3.

Assumed reactor transient boundary conditions are as identified in NEI 12-06 section 3.2.1.4 items 1, 2, 3 and 4 049-4.

No additional events or failures are assumed to occur immediately prior to or during the event. (Reference NEI 12-06, section 3.2.1.3 item 9) 049-5.

At Time=0 the event is initiated and all rods insert and no other event beyond a common site ELAP is occurring at any or all of the units. (NEI 12-06, section 3.2.1.3 item 9 and 3.2.1.4 item 1-4) 049-6.

At 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> (time critical at a time greater than 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />) an ELAP is declared and actions begin as defined in EA-12-049 compliance 049-7.

DC power and distribution can be credited for the duration determined per the EA-12-049 (FLEX) methodology for battery usage, (greater than 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> with a calculation limiting value of 8 hrs.) (NEI 12-06, section 3.2.1.3 item 8) 049-8.

Deployment resources are assumed to begin arriving at hour 6 and fully staffed by 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> 049-9.

All activities associated with plant specific EA-12-049 FLEX strategies that are not specific to implementation of the HCVS, including such items as debris removal, FLEX supply for drywell spray, FLEX water supply for Torus water level, communication, notifications, SFP level and makeup, security response, opening doors for cooling, and initiating conditions for the event, can be credited as previously evaluated for FLEX.

Applicable EA-13-109 generic assumptions:

109-1.

Site response activities associated with EA-13-109 actions are considered to have no access limitations associated with radiological impacts while RPV level is above 2/3 core height (core damage is not expected).

109-2.

Portable equipment can supplement the installed equipment after 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> provided the portable equipment credited meets the criteria applicable to the HCVS. An example is use of FLEX portable air supply equipment that is credited to recharge air lines for HCVS components after 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. The FLEX portable air supply used must be demonstrated to meet the SA Capable criteria that are defined in NEI 13-02 Section 4.2.4.2, 4.2.3 and Appendix D Section D.1.3.

109-3.

SFP Level is maintained with either on-site or off-site resources such that the SFP does not contribute to the analyzed source term (Reference HCVS-FAQ-07) 109-4.

Existing containment components design and testing values are governed by existing plant containment criteria (e.g., Appendix J) and are not subject to the testing criteria from NEI 13-02 (reference HCVS-FAQ-05 and NEI 13-02 section 6.2.2).

109-5.

Classical design basis evaluations and assumptions are not required when assessing the operation of the HCVS. The reason this is not required is that the order postulates an unsuccessful mitigation of an event such that an ELAP progresses to a severe accident with ex-vessel core debris which classical design basis evaluations are intended to prevent (Reference NEI 13-02 section 2.3.1).

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Part 1: General Integrated Plan Elements and Assumptions 109-6.

HCVS manual actions that require minimal operator steps and can be performed in the postulated thermal and radiological environment at the location of the step(s) (e.g., load stripping, control switch manipulation, valving-in nitrogen bottles) are acceptable to obtain HCVS venting dedicated functionality (reference HCVS-FAQ-01) 109-7.

HCVS dedicated equipment is defined as vent process elements that are required for the HCVS to function in an ELAP event that progresses to core melt ex-vessel, (Reference HCVS-FAQ-02 and White Paper HCVS-WP-01) 109-8.

Use of MAAP Version 4 or higher provides adequate assurance of the plant conditions (e.g., RPV water level, temperatures, etc.) assumed for Order EA-13-109 BDBEE and SA HCVS operation, (Reference FLEX MAAP Endorsement ML13190A201). Additional analysis using RELAP5/MOD 3, GOTHIC, PCFLUD, LOCADOSE and SHIELD are acceptable methods for evaluating environmental conditions in areas of the plant provided the specific version utilized is documented in the analysis.

109-9.

Utilization of NRC Published Accident evaluations (e.g. SOARCA, SECY-12-0157, and NUREG-1465) as related to Order EA-13-109 conditions are acceptable as references (Reference NEI 13-02 section 8).

109-10. Permanent modifications installed per EA-12-049 are assumed implemented and may be credited for use in Order EA-13-109 response.

109-11. This OIP is based on Emergency Operating Procedure changes consistent with EPG/SAGs Revision 3 as incorporated per the sites EOP/SAMG procedure change process.

109-12. Under the postulated scenarios of Order EA-13-109 the Control Room is adequately protected from excessive radiation dose per General Design Criterion (GDC) 19 in 10CFR50 Appendix A and no further evaluation of its use as the preferred HCVS control location is required. (reference HCVS-FAQ-01) In addition, adequate protective clothing and respiratory protection is available if required to address contamination issues.

Plant Specific HCVS Related Assumptions/Characteristics:

BFN-1 Each operating unit will have an individual release point above the highest point of the Reactor Building.

BFN-2 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.

BFN-3 The implementation of Order EA-13-109 will be staged for each operating unit such that the operating units that have not implemented the order will be able to vent via the existing plant stack.

BFN-4 BFN will design any exposed HCVS piping that is outside of the Reactor Building to seismic class 1 criteria.

[OIP OPEN ITEM 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.

[OIP OPEN ITEM 7] The implementation of the HCVS Design Change Notice (DCNs) will be staged so that there is no effect on the operating units.

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Part 2: Boundary Conditions for Wet Well Vent Provide a sequence of events and identify any time or environmental constraint required for success including the basis for the constraint.

HCVS Actions that have a time constraint to be successful should be identified with a technical basis and a justification provided that the time can reasonably be met (for example, action to open vent valves).

HCVS Actions that have an environmental constraint (e.g. actions in areas of High Thermal stress or High Dose areas) should be evaluated per guidance.

Describe in detail in this section the technical basis for the constraints identified on the sequence of events timeline attachment.

See attached sequence of events timeline (Attachment 2)

Ref: EA-13-109 Section 1.1.1, 1.1.2, 1.1.3 / NEI 13-02 Section 4.2.5, 4.2.6. 6.1.1 The operation of the HCVS will be designed to minimize the reliance on operator actions in response to hazards listed in Part 1. Immediate operator actions will be completed by plant personnel and will include the capability for remote-manual initiation from the HCVS control station. A list of the remote manual actions performed by plant personnel to open the HCVS vent path can be found in the following table (2-1). A HCVS Extended Loss of AC Power (ELAP) Failure Evaluation table, which shows alternate actions that can be performed, is included in Attachment 4.

Table 2-1 HCVS Remote Manual Actions Primary Action Primary Location /

Component Notes

1. Verify that Primary Containment Isolation valves are closed:

FCV-64-18, 19, 20, 21.

FSV 84-8B & 8C FCV 76-19 & 24 Indicating lights located in the MCR

2. Disable PCIV keylock switch if required.

Panels in MCR containing PCIV keylock switch Ref. EOI Appendix 13

3. Verify that power supplies for all valves and instruments can be supplied by dedicated batteries.

Instruments and controls located in the MCR A 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> supply of power will be available to the HCVS. After 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of operation the portable generators may be aligned to supply power to the HCVS Phase I OIP Page E2-7 of 59 Revision 1 Revision 1 of Tennessee Valley Authoritys 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-13-109)

Part 2: Boundary Conditions for Wet Well Vent

4. Verify that the pneumatic supply to the CIVs required for service is operable with replaceable nitrogen bottles Nitrogen bottles will be located in an area that is accessible to operators, preferably near the ROS located in the associated diesel generator building.

Prior to depletion of the pneumatic sources actions will be required to connect back-up sources at a time greater than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

5. Open Wetwell PCIVs FCV 221 & 222.

Hand switches located in the MCR panel And at the (ROS by operation of manual valves.

To minimize the impact to operational hazards the HCVS controls will be located in areas where sustained operation is possible accounting for expected temperatures and radiological conditions in the HCVS vent pipe and attached components without extreme heat stress or radiological over exposure to the operators.

HCVS components may serve multiple functions described in the plant Current License Basis (CLB).

For BFN this is inclusive of:

Containment Isolation Valves in the HCVS may provide a containment isolation function independent of the HCVS function.

Containment Isolation Valve position indication for valves in the HCVS may be used for post-accident indications Instrumentation supporting HCVS and non HCVS functions Components required for manual operation will be placed in areas that are readily accessible to plant operators, and not require additional actions, such as the installation of ladders or temporary scaffolding, to operate the system. The design strategy will evaluate potential plant conditions and use acquired knowledge of these areas to provide input to system operating procedures, training, choice of protective clothing, required tools and equipment, and portable lighting. The evaluation will include considerations such as, how temperatures would elevate due to extended loss of AC power conditions and the lighting that would be available following beyond design basis external events. The use of handheld or portable lighting for operations personnel is an acceptable practice.

A timeline was developed to identify required operator response times and potential environmental constraints. This timeline is based upon the following three cases:

1. Case 1 is based on the action response times developed for FLEX when utilizing anticipatory venting in a BDBEE without core damage.

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Part 2: Boundary Conditions for Wet Well Vent

2. Case 2 is based on a SECY-12-0157 long term station blackout (LTSBO) (or ELAP) with failure of RCIC after a black start where failure occurs because of subjectively assuming over injection.

3. Case 3 is based on NUREG-1935 (SOARCA) results for a prolonged SBO (or ELAP) with the loss of RCIC case without black start.

Discussion of time constraints identified in Attachment 2 for the 3 timeline cases identified above 4-8 Hours, Initiate use of HCVS per site procedures to maintain containment parameters below design limits and within the limits that allow continued use of RCIC - The reliable operation of HCVS will be met because HCVS meets the seismic requirements identified in NEI 13-02 and will be powered by DC buses with motive force supplied to HCVS valves from installed nitrogen storage bottles. Critical HCVS controls and instruments associated with containment will be DC powered and operated from the MCR or a Remote Operating Station on each unit. The DC power for HCVS will be available as long as the HCVS is required. HCVS battery capacity will be available for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. In addition, when available Phase 2 FLEX Portable Generator (PG) can provide power before battery life is exhausted. Thus initiation of the HCVS from the MCR or the Remote Operating Station within 4-8 hours is acceptable because the actions can be performed any time after declaration of an ELAP until the venting is needed at 4-8 hours for BDBEE venting. This action can also be performed for SA HCVS operation which occurs at a time further removed from an ELAP declaration as shown in Attachment 2.

After 24 Hours, supplemental nitrogen bottles will be moved into position to supplement the Nitrogen supply at the Remote Operating Station. The Nitrogen bottles can be replenished one at a time leaving the other tanks supplying the HCVS. This can be performed at any time prior to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to ensure adequate capacity is maintained so this time constraint is not limiting.

At 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> portable generators will be connected to the 480V unit battery chargers to supply power to HCVS critical components/instruments - Time critical after 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. Current 250V Unit batteries are calculated to last 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. PG will be staged beginning at approximately 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> time frame (Reference 28, FLEX OIP). Thus the PGs will be available to be placed in service at any point after 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> as required to supply power to HCVS critical components/instruments.

A PG will be maintained in an on-site FLEX storage building. PG will be transferred and staged via haul routes and staging areas evaluated for impact from external hazards. Modifications will be implemented to facilitate the connections and operational actions required to supply power within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> which is acceptable because the actions can be performed any time after declaration of an ELAP until the repowering is needed at greater than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> Discussion of radiological and temperature constraints identified in Attachment 2

1. 4-8 Hours, Initiate use of HCVS per site procedures to maintain containment parameters below design limits and within the limits that allow continued use of RCIC - The reliable operation of HCVS will be met because HCVS meets the seismic requirements identified in NEI 13-02 and will be powered by DC buses with motive force supplied to HCVS valves from an installed nitrogen supply. Critical HCVS controls and instruments associated with containment will be DC powered and operated from the MCR or a Remote Operating Station Phase I OIP Page E2-9 of 59 Revision 1 Revision 1 of Tennessee Valley Authoritys 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-13-109)

Part 2: Boundary Conditions for Wet Well Vent on each unit. After 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />, Phase 2 FLEX Portable Generator (PG) can provide power through the 250V Unit Battery before battery life is exhausted. Thus initiation of the HCVS from the MCR or the Remote Operating Station within 4-8 hours is acceptable because the actions can be performed any time after declaration of an ELAP until the venting is needed for BDBEE venting. This action can also be performed for severe accident HCVS operation which occur at a time further removed from an ELAP declaration as shown in Attachment 2.

2. Prior to 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />, based on battery depletion, power supply will be swapped from Unit batteries to dedicated HCVS batteries to ensure power to the inverters. Access to the transfer switch will be in the diesel buildings.

3. At >24 hours, additional nitrogen bottles will be aligned to supplement the nitrogen supply as stated for the related time constraint item.

4. At 8 Hours, temporary generators will be installed and connected to power up Unit Battery chargers using a Portable Generator (PG) to supply power to HCVS critical components/instruments - Time critical after 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. Current battery durations are calculated to last 12hours (Reference 32). PG will be connected at 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> time frame (Reference 28). Thus the PGs will be available to be placed in service at any point after 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> as required to supply power to HCVS critical components/instruments. The connections, location of the PG and access for refueling will be located in an area that is accessible to operators in the Control Building or in the yard area.

Provide Details on the Vent characteristics Vent Size and Basis (EA-13-109 Section 1.2.1 / NEI 13-02 Section 4.1.1)

What is the plants licensed power? Discuss any plans for possible increases in licensed power (e.g. MUR, EPU).

What is the nominal diameter of the vent pipe in inches/ Is the basis determined by venting at containment design pressure, Primary Containment Pressure Limit (PCPL), or some other criteria (e.g. anticipatory venting)?

Vent Capacity (EA-13-109 Section 1.2.1 / NEI 13-02 Section 4.1.1)

Indicate any exceptions to the 1% decay heat removal criteria, including reasons for the exception. Provide the heat capacity of the suppression pool in terms of time versus pressurization capacity, assuming suppression pool is the injection source.

Vent Path and Discharge (EA-13-109 Section 1.1.4, 1.2.2 / NEI 13-02 Section 4.1.3, 4.1.5 and Appendix F/G)

Provides a description of Vent path, release path, and impact of vent path on other vent element items.

Phase I OIP Page E2-10 of 59 Revision 1 Revision 1 of Tennessee Valley Authoritys 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-13-109)

Part 2: Boundary Conditions for Wet Well Vent Power and Pneumatic Supply Sources (EA-13-109 Section 1.2.5 & 1.2.6 / NEI 13-02 Section 4.2.3, 2.5, 4.2.2, 4.2.6, 6.1)

Provide a discussion of electrical power requirements, including a description of dedicated 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> power supply from permanently installed sources. Include a similar discussion as above for the valve motive force requirements. Indicate the area in the plant from where the installed/dedicated power and pneumatic supply sources are coming Indicate the areas where portable equipment will be staged after the 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> period, the dose fields in the area, and any shielding that would be necessary in that area. Any shielding that would be provided in those areas Location of Control Panels (EA-13-109 Section 1.1.1, 1.1.2, 1.1.3, 1.1.4, 1.2.4, 1.2.5 / NEI 13-02 Section 4.1.3, 4.2.2, 4.2.3, 4.2.5, 4.2.6, 6.1.1 and Appendix F/G)

Indicate the location of the panels, and the dose fields in the area during severe accidents and any shielding that would be required in the area. This can be a qualitative assessment based on criteria in NEI 13-02.

Hydrogen (EA-13-109 Section 1.2.10, 1.2.11, 1.2.12 / NEI 13-02 Section 2.3,2.4, 4.1.1, 4.1.6, 4.1.7, 5.1, &

Appendix H)

State which approach or combination of approaches the plant will take to address the control of flammable gases, clearly demarcating the segments of vent system to which an approach applies Unintended Cross Flow of Vented Fluids (EA-13-109 Section 1.2.3, 1.2.12 / NEI 13-02 Section 4.1.2, 4.1.4, 4.1.6 and Appendix H)

Provide a description to eliminate/minimize unintended cross flow of vented fluids with emphasis on interfacing ventilation systems (e.g. SGTS). What design features are being included to limit leakage through interfacing valves or Appendix J type testing features?

Prevention of Inadvertent Actuation (EA-13-109 Section 1.2.7/NEI 13-02 Section 4.2.1)

The HCVS shall include means to prevent inadvertent actuation Component Qualifications (EA-13-109 Section 2.1 / NEI 13-02 Section 5.1, 5.3)

State qualification criteria based on use of a combination of safety related and augmented quality dependent on the location, function and interconnected system requirements Monitoring of HCVS (Order Elements 1.1.4, 1.2.8, 1.2.9/NEI 13-02 4.1.3, 4.2.2, 4.2.4, and Appendix F/G)

Provides a description of instruments used to monitor HCVS operation and effluent. Power for an instrument will require the intrinsically safe equipment installed as part of the power sourcing Component reliable and rugged performance (EA-13-109 Section 2.2 / NEI 13-02 Section 5.2, 5.3)

HCVS components including instrumentation should be designed, as a minimum, to meet the seismic design requirements of the plant.

Components including instrumentation that are not required to be seismically designed by the design basis of the plant should be designed for reliable and rugged performance that is capable of ensuring HCVS functionality following a seismic event. (reference ISG-JLD-2012-01 and ISG-JLD-2012-03 for seismic details.)

Phase I OIP Page E2-11 of 59 Revision 1 Revision 1 of Tennessee Valley Authoritys 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-13-109)

Part 2: Boundary Conditions for Wet Well Vent The components including instrumentation external to a seismic category 1. (or equivalent building or enclosure should be designed to meet the external hazards that screen-in for the plant as defined in guidance NEI 12-06 as endorsed by JLD-ISG-12-01 for Order EA-12-049.)

Use of instruments and supporting components with known operating principles that are supplied by manufacturers with commercial quality assurance programs, such as ISO9001. The procurement specifications shall include the seismic requirements and/or instrument design requirements, and specify the need for commercial design standards and testing under seismic loadings consistent with design basis values at the instrument locations.

Demonstration of the seismic reliability of the instrumentation through methods that predict performance by analysis, qualification testing under simulated seismic conditions, a combination of testing and analysis, or the use of experience data. Guidance for these is based on sections 7, 8, 9, and 10 of IEEE Standard 344-2004, IEEE Recommended Practice for Seismic Qualification of Class 1E Equipment for Nuclear Power Generating Stations, or a substantially similar industrial standard could be used.

Demonstration that the instrumentation is substantially similar in design to instrumentation that has been previously tested to seismic loading levels in accordance with the plant design basis at the location where the instrument is to be installed (g-levels and frequency ranges). Such testing and analysis should be similar to that performed for the plant licensing basis.

Vent Size and Basis The HCVS wetwell path is designed for venting steam/energy at a nominal capacity of 1% of 3952 MW thermal power at pressure of 56 psig. This pressure is the lower of the containment design pressure (56 psig) and the PCPL value (62 psig). The thermal power is based on a power uprate of

~15% above the currently licensed thermal power of 3458 MWt. The size of the wetwell portion of the HCVS is 14 inches in diameter which provides adequate capacity to meet or exceed the Order criteria.

The primary design objective of the HCVS is to provide sufficient venting capacity to prevent a long-term overpressure failure of the containment by keeping the containment pressure below the lower value of either Primary Containment Pressure Limit (PCPL) or containment design pressure, and maintaining Pressure Suppression Capability such that the safety relief valves (SRVs) can be opened and closed as required by plant conditions. Operational functionality of these valves will ensure the capability to depressurize the RPV to permit injection of low head injection systems and to maintain the containment pressure boundary.

The wet well vent will be sized to operate under conditions of constant heat input at a rate equal to 1% of rated thermal power and containment pressure equal to the lesser of the PCPL or containment design pressure. Therefore, the exhaust-flow through the wetwell vent would be sufficient to prevent the containment pressure from exceeding design limits.

Phase I OIP Page E2-12 of 59 Revision 1 Revision 1 of Tennessee Valley Authoritys 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-13-109)

Part 2: Boundary Conditions for Wet Well Vent

[OIP OPEN ITEM 8] The wetwell vent will be designed to remove 1% of rated thermal power at EPU conditions.

During a severe accident, temperature of gases in the wetwell and drywell will differ due to insufficient removal of decay heat from fission products resulting in superheat or non-saturated conditions in the drywell. The suppression pool/wetwell of a BWR Mark I/II containment can be considered to be in a saturated condition. The plant-specific PCPL determination provides a temperature range for the suppression pool of 70ºF to 350ºF. Therefore, the design temperature for the wetwell vent portions of the HCVS are recommended to be based on the 350ºF upper bound of the EPG/SAG bases document which is above the saturation temperature corresponding to typical PCPL values.

Anticipatory venting of primary containment may be used in the BFN HCVS design to preclude elevated containment temperature, hydrogen generation, containment pressure and extend RCIC operation. Early removal of energy from containment during an ELAP via the containment vents is an effective action that can be taken to support the containment and core cooling safety function capabilities described in NEI 12-06 (Reference 10) Table 3-1 for Mark I containment designs.

Anticipatory venting provides a controlled vent path (for exhausted/scrubbed reactor steam) and maintains operation of an installed (operator-familiar) injection system that provides a reliable strategy for maintaining long term functionality of Containment (and the Core).

Vent Capacity The 1% capacity value at BFN is acceptable based on analysis demonstrating that the suppression pool pressure suppression capacity is sufficient to absorb the decay heat generated during the first 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br />. The vent would then be able to prevent containment pressure from increasing above the containment design pressure. As part of the detailed design, the duration of suppression pool decay heat absorption capability has been confirmed. (Reference 31)

Vent Path and Discharge The HCVS vent path at BFN will consist of a wetwell vent on each unit. There will be no connection to the existing drywell vent. The proposed HCVS vent path for the wetwell will exit the Reactor Building 565.0 elevation through an underground pipe. This pipe will be routed approximately 200 feet vertically up the outside of the Reactor Building. The HCVS path will pass through the BFN superstructure to the roof of the Reactor Building. The effluent will be discharged at an elevated release point and the velocity and spacing of each unit will provide compliance with the Order EA-13-109 requirements of separation.

The HCVS discharge path is in the early design developmental stage and subject to refinement:

however, current consideration is that the HCVS vent will be routed to a point above any adjacent structure. Each discharge point is above the units Reactor Building such that the release point will vent away from emergency ventilation system intake and exhaust openings, MCR location, location of HCVS portable equipment, access routes required following an ELAP and BDBEE, and Phase I OIP Page E2-13 of 59 Revision 1 Revision 1 of Tennessee Valley Authoritys 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-13-109)

Part 2: Boundary Conditions for Wet Well Vent emergency response facilities; however, these must be considered in conjunction with other design criteria (e.g., flow capacity) and pipe routing limitations, to the degree practical. The routing of the Wet Well vent will follow the existing path to the Reactor Building wall. The proposed HCVS pipe will exit the Reactor Building wall and be routed through an existing valve pit to a vertical discharge path on the exterior side of the Reactor building wall. The HCVS piping will then pass through the superstructure that encases the refuel floor to an exit point on the roof. This path will provide an enhanced method to minimize any radiological dose to the operating staff and any exposed piping and supports will be designed for missile protection in accordance with Plant Design Basis.

The HCVS shall be designed for those accident conditions (before and after core damage) for which containment venting is relied upon to reduce the probability of containment failure. The BFN HCVS will be designed to protect the containment against over-pressurization in a beyond design basis accident such that the release of radioactive effluent will be maintained as a controlled process.

When anticipatory venting is performed at low containment pressure to maintain core cooling using FLEX strategies, there is no minimum required exhaust stack exit velocity, since without core damage there will be negligible levels of radionuclides and/or combustible gas in the effluent.

Therefore, there is no concern with entrainment of the stack effluent into the roof or downstream recirculation zones associated with airflow around the building.

Severe accident venting to maintain containment integrity may have the potential presence of significant quantities of radionuclides and/or combustible gas in the vent discharge that requires additional restrictions to be applied to the design and operation of the vent under severe accident conditions. ASHRAE HVAC design requirements are used as the guidance document, and it states that 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. Vent pipe design (e.g., pipe diameter at the exit) and conditions under which the vent is operated (e.g., minimum containment pressure at which the vent is operated; use of flow control devices) should be considered to ensure this is the predominant minimum release velocity under severe accident conditions.

Venting of the containment volume at accident pressures is considered to be predominately a high velocity evolution such that for the vast majority of time the effluent will be jetted up beyond the affected building recirculation zone. Effluent will not simply waft across a building roof as if released by a predominantly buoyancy driven exhaust stack but will be jetted upward from the vent due to momentum. By nature of any venting strategy there may be times when the effluent release velocity may drop below the stated 8000 fpm.

Under severe accident conditions the main purpose of the vent is to protect the containment function and use of the vent should not be limited by an effluent release velocity of 8000 fpm (e.g. venting at low pressure may be required to optimize the timing of a release or to optimize a venting strategy).

In such cases, the margin in containment pressure gained by venting is more important than dispersion of the effluent.

The design of the HCVS release point relative to the location of the air intakes for the control building will follow a general guidance of a 1:5 ratio. This allows a 1 foot vertical drop for every 5 feet of horizontal travel.

Phase I OIP Page E2-14 of 59 Revision 1 Revision 1 of Tennessee Valley Authoritys 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-13-109)

Part 2: Boundary Conditions for Wet Well Vent The detailed design will provide missile protection from ground level to the 664 elevation, from external events as defined by NEI 12-06 for the outside portions of the selected release stack or structure. This is a design consideration using reasonable protection features for the screened in hazards from NEI 12-06. Engineering will use design basis missile hazards methods in the calculations. BFN external missiles are detailed in Design Criteria BFN-50-C-7101 (Reference 33).

Power and Pneumatic Supply Sources All electrical power required for operation of HCVS components will be routed through a 250 VDC system which is normally supplied from two Unit Batteries, one for each electrical division. Battery power will be provided by the existing Unit batteries until load shed performed at which time the HCVS loads will be powered from dedicated HCVS Batteries. At 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, power will transfer back to the Unit Batteries, at which time the FLEX generators will be in service and will have recharged the Unit Batteries.

Pneumatic power is normally provided by the non-interruptible air system with backup nitrogen provided from installed nitrogen supply tanks. Following an ELAP event, station control air system is lost, and normal backup from installed nitrogen supply tanks is isolated. Therefore, for the first 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, pneumatic force will be supplied from newly installed nitrogen tanks. These tanks will supply the required motive force to those HCVS valves needed to maintain flow through the HCVS effluent piping.

1. The HCVS flow path valves are air-operated valves (AOV) with air-to-open and spring-to-shut.

Opening the valves from the MCR requires energizing an AC powered solenoid operated valve (SOV) and providing motive gas. The detailed design will provide a permanently installed power source and motive gas supply adequate for the first 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. Beyond the first 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, there will be FLEX portable generators that are able to sustain DC power. The capacity of the FLEX portable generators will have the capability to sustain extended operation and will be sized to supply the required FLEX and HCVS electrical loads. The initial stored motive gas will allow for a minimum of approximately 24 valve operating cycles for the HCVS valves for the first 24-hours.

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

[OIP OPEN ITEM 1] Perform assessment of temperature and radiological conditions.

The primary operating location, inclusive of the valve position indication, is designed for the expected Thermal and Radiological challenges posed by loss of ventilation (possible for the entire Sustained Operating period of 7 days), including any thermal challenge posed by operating the HCVS, and any radiological challenge posed by the HCVS on the equipment located at the control panel. The primary operating location will be the MCR and the dose allowable will comply with General Design Criteria 19 (5 Rem/person for the duration of the Phase I OIP Page E2-15 of 59 Revision 1 Revision 1 of Tennessee Valley Authoritys 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-13-109)

Part 2: Boundary Conditions for Wet Well Vent event).

3. All permanently installed HCVS equipment, including any connections required to supplement the HCVS operation during an ELAP (i.e., electric power and N2) will be located in areas reasonably protected from defined hazards listed in Part 1 of this report.

Power that is available following an ELAP to provide the required Containment Indications (See JLD-ISG-2012-01 for Order EA-12-049) will be available for the BFN HCVS. Indications required for Containment Pressure and Wetwell level are used to operate the HCVS (determine when to close to prevent negative pressure or air intrusion) and thus either must be available or the parametric values must be actively communicated to the HCVS control location.

4. All valves required to open the flow path will be designed for remote manual operation following an ELAP, such that the primary means of valve manipulation does not rely on use of a hand wheel, reach-rod or similar means that requires close proximity to the valve (reference FAQ HCVS-03). The ROS will be located in the Diesel Generator Buildings. These structures are not subject to the thermal and radiological conditions in the Reactor Building(s) and no ice vest or shielding is required. Any supplemental connections will be pre-engineered to minimize man-power resources and address environmental concerns. Required portable equipment will be reasonably protected from screened in hazards listed in Part 1 of this OIP.

The Alternate operation of the HCVS components to meet Order Element 1.2.5. Manual Operation of the PCIVs will be the use of a manual valve, to provide pneumatic supply to the PCIV, located at the ROS in the diesel generator buildings. The HCVS shall be capable of operating with dedicated and permanently installed equipment for at least 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> following the loss of normal power or loss of normal pneumatic supplies to air operated components during an extended loss of AC power. The ROS is inclusive of the manual valve and connections for pneumatic supply. The HCVS PCIVs and associated components are dedicated equipment that will be used for sustained operation.

5. Access to the locations described above will not require temporary ladders or scaffolding.

The primary and ROS control panels are located in normally occupied spaces or accessible to plant staff for all modes of operation including a severe accident. The panels will consider human factors and be designed so that ladders and scaffolding are not required.

Location of Control Panels The HCVS design allows initiating and then operating the HCVS from the MCR and the ROS located in the Diesel Generator Building(s); however, monitoring is from the MCR only. The MCR location is protected from adverse natural phenomena and is the normal control point for Plant Emergency Response actions.

The Remote Operating Station located in the Diesel Generator Building(s) has the same accessibility and habitability as the Main Control Room. Evaluations will be performed for the Diesel Generator Buildings to verify area temperatures are acceptable for ROS location. Radiological conditions will Phase I OIP Page E2-16 of 59 Revision 1 Revision 1 of Tennessee Valley Authoritys 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-13-109)

Part 2: Boundary Conditions for Wet Well Vent also vary with the source term over time and could either drop or rise depending on deposition of source term in the HCVS during use. However, based on the distance of the Remote Operating Station to the operating HCVS process piping the radiological conditions will conform to GDC 19 requirements.

The HCVS will include a means to monitor the effluent discharge for radioactivity that may be released from operation of the HCVS. The monitoring system will provide indication at the MCR control panel and shall be designed for sustained operation during an extended loss of AC power.

The HCVS design will provide a means to allow plant operators to readily determine, or have knowledge of HCVS vent valve position, effluent radiation levels with a range for severe accident service, pressure, temperature and the status of supporting systems, such as availability of electrical power and pneumatic supply pressure.

[OIP OPEN ITEM 9] Communication between the MCR and the ROS will be with handheld radios.

The temperature and heat load that exist in the MCR due to proximity to the undercooled containment has been considered for NRC Order EA-12-049 (FLEX) and EA-13-109 (HCVS) and are within guidelines. The opening of doors or placement of portable fans may be required during certain timeframes. The instrumentation will be capable of operating in the thermal and radiological environment for at least 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> without significant operator action.

The ROSs located outside the main control room have been determined to be readily accessible locations based on evaluations that include: accessibility, habitability, staffing sufficiency and providing communication capability with vent use decision makers.

Hydrogen_(EA-13-109 Section 1.2.10, 1.2.11, 1.2.12 / NEI 13-02 Section 2.3,2.4, 4.1.1, 4.1.6, 4.1.7, 5.1, & Appendix H)

As required by EA-13-109, Section 1.2.11, the HCVS must be designed such that it is able to either provide assurance that oxygen cannot enter and mix with flammable gas in the HCVS (so as to form a combustible gas mixture), or it must be able to accommodate the dynamic loading resulting from a combustible gas detonation. Several configurations are available which will support the former (e.g.,

purge, mechanical isolation from outside air, etc.) or the latter (design of potentially affected portions of the system to withstand a detonation relative to pipe stress and support structures).

The BFN HCVS will be designed to avoid a detonable mixture while remaining functional. A number of conditions as shown in attachment 2 must align to allow for a detonation to occur. A series of specific conditions must occur in order for a pressure spike high enough to potentially damage the vent pipe to be possible. The occurrence of such a set of conditions is extremely unlikely due mainly to the process of venting which will purge the vent system of available oxygen prior to a combustible mix occurring. After a venting evolution, the vent pipe would contain a large amount of steam (the predominant constituent of the effluent). The steam in the pipe would not collapse quickly, but would condense and slowly draw air down into the vent pipe. Once the steam has condensed, the air travelling down into the pipe would have marginal motive force to facilitate mixing. Although the hydrogen molecules would tend to diffuse into the air, the likelihood of a large homogeneous mixture of sufficient concentration being formed is remote. The more likely scenario, if an ignition occurred in an area where conditions were favorable, would be that the flame front would travel a short distance Phase I OIP Page E2-17 of 59 Revision 1 Revision 1 of Tennessee Valley Authoritys 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-13-109)

Part 2: Boundary Conditions for Wet Well Vent along the pipe to a point (in both directions) where there was no longer a combustible mix that could support the flame.

The BFN HCVS will be designed to allow the vent to operate during all three cases in Attachment 2, inclusive of a severe accident that may produce hydrogen. The vent path will be designed so that the path can be open to the release point and provide for the movement of any built-up gases. The piping will minimize low points and the upper segment will be designed with a check valve to eliminate the ability of air to enter the HCVS during periods when the PCIVs may close and steam may be condensing in the piping. For design purposes, the HCVS that is subject to hydrogen presence is not required to consider assumed simultaneous loads that would not be present or occur during the venting of hydrogen.

Relative buoyancy of hydrogen would also tend to alleviate any sustained mixing of the oxygen as it leaked by the check valve. Once venting has ceased, the atmosphere in the contained volume in the HCVS would become relatively stagnant. As such oxygen and nitrogen (air), which may slowly enter the volume due to leakage past the check valve, would not tend to mix so much with the hydrogen layer but would tend to pass though it and settle out low in the pipe run. Due to the close molecular weights of nitrogen and oxygen gas (14 and 16 respectively) they would tend to remain mixed and both remain low in the piping. Hydrogen would tend to rise in such an environment and exist quite close to the check valve.

Instruments required for HCVS operation will be located upstream of the check valve and not prone to detonation loading.

The design concept of using a check valve is to bottle up the steam and hydrogen in the pipe volume between a downstream check valve and the upstream PCIV. There are check valves available that have near zero leakage for these applications and would prevent backflow up near the exit point of the HCVS. Based on the run-up distance required for a deflagration to detonation transition to occur, detonation loading would be ruled out for the downstream piping. With the disc swinging up, gravity would assist the spring closure mechanism to limit leakage to an absolute minimum.

A check valve will be placed near the roof level to minimize the potential for deflagration and BFN will use a blow off cap to prevent foreign material from entering the HCVS piping.

Unintended Cross Flow of Vented Fluids The HCVS uses the Containment Purge and Inerting System containment isolation valves as the boundary to other plant systems. These containment isolation valves are AOVs and they are air-to-open and spring-to-shut. An SOV must be energized to allow the motive air to open the valve. These Primary Containment Isolation Valves (PCIV) are maintained leak tight and tested in accordance with the stations Appendix J Program.

Each HCVS containment penetration will have two in-series PCIVs as required by GDC 56. These PCIVs will be evaluated for the required BDBEE process conditions. The design basis requirements will not be altered by the implementation of the modification to implement NRC Order EA-13-109.

Phase I OIP Page E2-18 of 59 Revision 1 Revision 1 of Tennessee Valley Authoritys 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-13-109)

Part 2: Boundary Conditions for Wet Well Vent The HCVS path upstream of the HCVS PCIVs will be a multipurpose containment penetration that serves purge and inerting flow. The HCVS path downstream of the second PCIV must be analyzed for the condition of 350°F with corresponding PCPL values. The analysis of the non-HCVS downstream of any boundary valve only has to consider consequences of heat transfer and leakage with the boundary valve closed.

The primary containment connections that are upstream of the HCVS PCIVs are in accordance with 10 CFR 50, Appendix J, Type C testing. These paths accordingly are protected by redundant and diversely powered isolation valves. In standby conditions the normal state of the Torus Purge and Vent Valves (PCIVs) is closed. Any leakage through these valves to the HCVS line would be determined by the Appendix J testing. During HCVS Operation the secondary containment bypass leakage criteria would not apply.

The HCVS boundary valves are any valves which serve to isolate the HCVS from another system.

For BFN these valves are safety related PCIVs that function as required by 10 CFR 50, Appendix J.

Their safety related function is to maintain the containment pressure boundary during a design bases accident. Downstream of the PCIVs the HCVS in each unit will not interact with any other system and no crossflow potential exists. The implementation of NRC Order EA-13-109 will provide independence of the discharge path for all three units.

Prevention of Inadvertent Actuation EOP/ERG operating procedures provide clear guidance that the HCVS is not to be used to defeat containment integrity during any design basis transients or accident. In addition, the HCVS will be designed to provide features to prevent inadvertent actuation due to a design error, equipment malfunction, or operator error such that any credited containment accident pressure (CAP) that would provide net positive suction head to the emergency core cooling system (ECCS) pumps will be available (inclusive of a design basis loss-of-coolant accident (DBLOCA)). However, the ECCS pumps will not have normal power available because of the starting boundary conditions of an ELAP.

BFN will use Containment Accident Pressure (CAP) to provide sufficient NPSH for the RCIC pump during the BDBEE. Analysis will be performed to ensure that the suppression pool water level in conjunction with pressure will provide sufficient margin to operate the RCIC pump for sustained service.

The features that prevent inadvertent actuation are two PCIVs in series powered from different divisions and key lock switches.

Component Qualifications The HCVS components downstream of the second containment isolation valve will be routed in a seismically qualified structure or exterior to the Reactor Building. HCVS components that directly interface with the primary containment pressure boundary will be considered safety related, as the existing system is safety related. The containment system limits the leakage or release of radioactive materials to the environment to prevent offsite exposures from exceeding the guidelines of 10CFR100. During normal or design basis operations, this means serving as a pressure boundary to prevent release of radioactive material.

Phase I OIP Page E2-19 of 59 Revision 1 Revision 1 of Tennessee Valley Authoritys 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-13-109)

Part 2: Boundary Conditions for Wet Well Vent Likewise, any electrical or controls component that interfaces with Class 1E power sources will be considered safety related up to and including appropriate isolation devices such as fuses or breakers, as their failure could adversely impact containment isolation and/or a safety-related power source.

The remaining components will be considered Augmented Quality. Newly installed piping and valves will be seismically qualified to handle the forces associated with the seismic margin earthquake (SME) back to their isolation boundaries. Electrical and controls components will be seismically qualified and will include the ability to handle harsh environmental conditions (although they will not be considered part of the site Environmental Qualification (EQ) program).

The HVCS will be required to be capable of functioning during severe accidents in which the containment function is not compromised by the severe accident conditions. The HCVS equipment is designed to provide reasonable assurance of operation in the severe accident environment for which they are intended to function and over the time span for which they are needed. However, the environmental requirements of 10 CFR 50.49 are design basis regulatory requirements and as such are not applicable under severe accident conditions.

Drywell radiological conditions should be consistent with the conditions assumed in the plants current licensing basis (CLB) for a major accident. Such accidents have generally been assumed to result in substantial meltdown of the core with subsequent release of appreciable quantities of fission products (e.g., Technical Information Document (TID) 14844, Calculation of Distance Factors for Power and Test Reactor Sites (March 1962), or NUREG-1465, Accident Source Terms for Light-Water Nuclear Power Plants consistent with the current design basis of the plant).

Routing considerations will account for radiological conditions along both the piping path and at the control stations where the new equipment will be placed. Additionally, remote instrumentation locations will be evaluated.

HCVS components including instrumentation will meet the quality design requirements of the plant, ensuring HCVS functionality. The HCVS up to and including the second isolation valve is designed to the same quality requirements of the connected system. HCVS elements that are not noted above will be reliable and rugged to ensure HCVS functionality following a seismic event. Additionally, non-safety equipment installed to meet the requirements of Order EA-13-109 must be implemented so it does not degrade the existing safety-related systems.

The instrumentation that is required for HCVS operation should be capable of operating in the thermal and radiological environment for at least 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> without significant operator action. The restriction on permanently installed equipment and operator actions only exists for the 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> period to ensure HCVS viability for at least a 7 day mission time.

HCVS instrumentation performance (i.e. accuracy and precision) need not exceed that of similar plant installed equipment. Additionally, radiation monitoring instrumentation accuracy and range will be sufficient to confirm flow of radionuclides through the HCVS.

Phase I OIP Page E2-20 of 59 Revision 1 Revision 1 of Tennessee Valley Authoritys 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-13-109)

Part 2: Boundary Conditions for Wet Well Vent The HCVS instruments, including valve position indication, process instrumentation, radiation monitoring, and support system monitoring, will be qualified by using one or more of the three methods described in the ISG, which includes:

1. Purchase of instruments and supporting components with known operating principles from manufacturers with commercial quality assurance programs (e.g., ISO9001) where the procurement specifications include the applicable seismic requirements, design requirements, and applicable testing.

2. Demonstration of seismic reliability via methods that predict performance described in IEEE 344-2004.

3. Demonstration that instrumentation is substantially similar to the design of instrumentation previously qualified.

Instrument Qualification Method*

HCVS Process Temperature ISO9001 / IEEE 344-2004 / Demonstration HCVS Process Pressure ISO9001 / IEEE 344-2004 / Demonstration HCVS Process Radiation Monitor ISO9001 / IEEE 344-2004 / Demonstration HCVS Process Valve Position ISO9001 / IEEE 344-2004 / Demonstration HCVS Pneumatic Supply Pressure ISO9001 / IEEE 344-2004 / Demonstration HCVS Electrical Power Supply Availability ISO9001 / IEEE 344-2004 / Demonstration

• The specific qualification method used for each required HCVS instrument will be reported in future 6 month status reports.

Monitoring of HCVS The BFN wetwell HCVS will be capable of being manually operated during sustained operations from a control panel located in the MCR and will meet the requirements of Order element 1.2.4. The MCR is a readily accessible location with no further evaluation required. Control Room dose associated with HCVS operation conforms to GDC 19/Alternate Source Term (AST). Additionally, to meet the intent for a secondary control location of section 1.2.5 of the Order, a readily accessible ROS will also be incorporated into the HCVS design as described in NEI 13-02 section 4.2.2.1.2.1. The controls at the ROS location will be accessible and functional under a range of plant conditions, including severe accident conditions with due consideration to source term and dose impact on operator exposure, extended loss of AC power (ELAP), and inadequate containment cooling. An evaluation will be performed to determine accessibility to the location, habitability, staffing sufficiency, and communication capability with Vent-use decision makers.

Phase I OIP Page E2-21 of 59 Revision 1 Revision 1 of Tennessee Valley Authoritys 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-13-109)

Part 2: Boundary Conditions for Wet Well Vent The wetwell HCVS will include means to monitor the status of the vent system in the MCR. Included in the current design of the reliable hardened vent (RHV) are control switches in the MCR with valve position indication. Following load shed, the installed HCVS Battery and nitrogen supply provides for operation of the system for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. Beyond the first 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, the ability to maintain these valves open or closed will be provided with replaceable nitrogen bottles and FLEX generators.

The wetwell HCVS will include indications for vent pipe pressure, temperature, and effluent radiation levels at the MCR. Other important information on the status of supporting systems, such as power source status and pneumatic supply pressure, will also be included in the design and located to support HCVS operation. The wetwell HCVS includes existing containment pressure and wetwell level indication in the MCR to monitor vent operation. This monitoring instrumentation provides the indication from the MCR as per Requirement 1.2.4 and will be designed for sustained operation during an ELAP event.

Component Reliable and Rugged Performance The HCVS downstream of the second containment isolation valve, including piping and supports, electrical power supply, valve actuator pneumatic supply, and instrumentation (local and remote) components, will be designed/analyzed to conform to the requirements consistent with the applicable design codes (e.g., Non-safety, Cat 1, SS and 300# ASME or B31.1, NEMA 4, etc.) for the plant and to ensure functionality following a design basis earthquake.

Additional modifications required to meet the Order will be reliably functional at the temperature, pressure, and radiation levels consistent with the vent pipe conditions for sustained operations. The instrumentation/power supplies/cables/connections (components) will be qualified for temperature, pressure, radiation level, and total integrated dose radiation for the Effluent Vent Pipe and HCVS ROS location.

Conduit design will be installed to Seismic Class 1 criteria. Both existing and new barriers will be used to provide a level of protection from missiles when equipment is located outside of seismically qualified structures. Augmented quality requirements, will be applied to the components installed in response to this Order.

If the instruments are purchased as commercial-grade equipment, they will be qualified to operate under severe accident environment as required by NRC Order EA-13-109 and the guidance of NEI 13-02. These qualifications will be bounding conditions for BFN.

For the instruments required after a potential seismic event, the following methods will be used to verify that the design and installation is reliable/rugged and thus capable of ensuring HCVS functionality following a seismic event. Applicable instruments are rated by the manufacturer (or otherwise tested) for seismic impact at levels commensurate with those of postulated severe accident event conditions in the area of instrument component use using one or more of the following methods:

Phase I OIP Page E2-22 of 59 Revision 1 Revision 1 of Tennessee Valley Authoritys 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-13-109)

Part 2: Boundary Conditions for Wet Well Vent

1. Demonstration of seismic motion will be consistent with that of existing design basis loads at the installed location;

2. Substantial history of operational reliability in environments with significant vibration with a design envelope inclusive of the effects of seismic motion imparted to the instruments proposed at the location;

3. Adequacy of seismic design and installation is demonstrated based on the guidance in Sections 7, 8, 9, and 10 of IEEE Standard 344-2004, IEEE Recommended Practice for Seismic Qualification of Class 1E Equipment for Nuclear Power Generating Stations, (Reference 27) or a substantially similar industrial standard;

4. Demonstration that proposed devices are substantially similar in design to models that have been previously tested for seismic effects in excess of the plant design basis at the location where the instrument is to be installed (g-levels and frequency ranges); or

5. Seismic qualification using seismic motion consistent with that of existing design basis loading at the installation location.

HCVS components including instrumentation will be designed, as a minimum, to meet the BFN seismic design requirements. Components including instrumentation that are not required to be seismically designed by the design basis of the plant will be designed for reliable and rugged performance that is capable of ensuring HCVS functionality following a seismic event. (Reference ISG-JLD-2012-01 and ISG-JLD-2013-02 [References 6 & 8] for seismic details.).

The components including instrumentation external to a Seismic Category 1 structure will be designed to meet the external hazards that screen in for BFN as defined in guidance NEI 12-06 as endorsed by JLD-ISG-2012-01 for Order EA-12-049.

The BFN HCVS and its associated components will comply with the structural requirements as defined in the BFN design criteria for FLEX mitigation systems (Reference 35).

Phase I OIP Page E2-23 of 59 Revision 1 Revision 1 of Tennessee Valley Authoritys 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-13-109)

Part 2: Boundary Conditions for WW Vent: BDBEE Venting Determine venting capability for BDBEE Venting, such as may be used in an ELAP scenario to mitigate core damage.

Ref: EA-13-109 Section 1.1.4 / NEI 13-02 Section 2.2 First 24 Hour Coping Detail Provide a general description of the venting actions for first 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> using installed equipment including station modifications that are proposed.

Ref: EA-13-109 Section 1.2.6 / NEI 13-02 Section 2.5, 4.2.2 The operation of the HCVS will be designed to minimize the reliance on operator actions for response to the ELAP and BDBEE hazards identified in part 1 of this OIP. Immediate operator actions can be completed by Operators from the HCVS control station(s) and include remote-manual initiation. The operator actions required to open a vent path are as described in Table 2-1.

Remote-manual is defined in this report as a non-automatic power operation of a component and does not require the operator to be at or in close proximity to the component. No other operator actions are required to initiate venting under the guiding procedural protocol.

The HCVS will be designed to allow initiation, control, and monitoring of venting from the Main Control Room and will be able to be operated from an installed Remote Operating Station. This location minimizes plant operators exposure to adverse temperature and radiological conditions and is protected from hazards assumed in Part 1 of this report.

Permanently installed power and motive gas capability will be available to support operation and monitoring of the HCVS for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

System control:

i.

Active: PCIVs are operated in accordance with EOPs/SOPs to control containment pressure. The HCVS will be designed for approximately 24 open/close cycles under ELAP conditions over the first 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> following an ELAP. Controlled venting will be permitted in the revised EPGs and associated implementing EOPs.

[OIP OPEN ITEM 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.

ii.

Passive: Inadvertent actuation protection is provided by the current containment isolation circuitry associated with the PCIVs used to operate the HCVS. In addition, the HCVS isolation valves are normally key-locked closed.

Phase I OIP Page E2-24 of 59 Revision 1 Revision 1 of Tennessee Valley Authoritys 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-13-109)

Part 2: Boundary Conditions for WW Vent: BDBEE Venting Greater Than 24 Hour Coping Detail Provide a general description of the venting actions for greater than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> using portable and installed equipment including station modifications that are proposed.

Ref: EA-13-109 Section 1.2.4, 1.2.8 / NEI 13-02 Section 4.2.2 Available personnel will be able to connect supplemental motive gas and electrical power to the HCVS (not required within first 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />). Connections for supplementing electrical power and motive gas required for HCVS will be located in accessible areas with reasonable protection per NEI 12-06 that minimize personnel exposure to adverse conditions for HCVS initiation and operation. Sufficient nitrogen and battery capacity will be installed to support operations for up to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> following the ELAP event. BFN will credit FLEX to sustain power for a BDBEE ELAP for the period after 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

[OIP OPEN ITEM 3] Perform an evaluation for FLEX portable generator 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.

These actions provide long term support for HCVS operation for the period beyond 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to 7 days (sustained operation time period) because on-site and off-site personnel and resources will have access to the unit(s) to provide needed action and supplies.

Details:

Provide a brief description of Procedures / Guidelines:

Confirm that procedure/guidance exists or will be developed to support implementation.

Primary Containment Control Flowchart exists to direct operations in protection and control of containment integrity, including use of the Hardened Containment Vent System. Other site procedures for venting containment using the HCVS include: Technical Support Guidelines; Emergency Containment Venting; Primary Containment Venting for Hydrogen and Oxygen Control. These guidelines will be revised to support the operation of the HCVS.

[OIP OPEN ITEM 4] Revise 1/2/3-EOI Appendix 13 to include venting for loss of DC power Identify modifications:

List modifications and describe how they support the HCVS Actions.

EA-12-049 Modifications

1. DCN 70745 (Complete): Install a Flex Equipment Storage Building (FESB). This structure is a permanent building to house all of the equipment to respond to a BDBEE. Some of the major components housed in this building are the portable generators, tow vehicles, FLEX pumps, FLEX Portable Generators and debris removal equipment Phase I OIP Page E2-25 of 59 Revision 1 Revision 1 of Tennessee Valley Authoritys 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-13-109)

Part 2: Boundary Conditions for WW Vent: BDBEE Venting

2. DCN 71329: This change package will provide connections for the FLEX pumps to align water to various systems that support the HCVS. These mechanical connections will be on safety related sections of the RHRSW and EECW system. The RCIC system will be provided cooling water to the lube oil cooler to extend running time. RHRSW will provide water to the RPV, wetwell and the drywell sprays as required for cooling.

3. DCN 70810 (Unit 2 - Complete), DCN 71387 (Unit 1), and DCN 71386 (Unit 3) FLEX Nitrogen supply will provide a pneumatic supply to the Main Steam Relief Valves to allow depressurization of the RPV.

4. DCN 71335 (Unit 2 - Complete), DCN 71162 (Unit 1), & DCN 71336 (Unit 3) FLEX Battery backed instrumentation will provide containment monitoring capability in the MCR.

5. DCN 71470 (Complete) FLEX 480V portable generators are deployed to provide backup power to the 480V power system via the main unit battery chargers 1A, 2A, 3A and 2B.

6. DCN 71454 (Complete) FLEX deployment road and pump landing is used to place equipment into operation that has been stored in the FESB

7. DCN 71705 (Complete) FLEX 4kv spare portable generators are stored in the FESB and be placed into service to power equipment as required during phase 2 and 3 of the BDBEE. This power supply will be connected to the shutdown boards or directly to the emergency diesel generator output.

EA-13-109 Modifications DCN 71389 (Unit 1), 71390 (Unit 2), 71391 (Unit 3) are design changes that will be used to implement the HCVS for BFN. Each design change will be staged to allow pre-outage implementation of applicable portions of the system.

A power supply will be installed to allow the required HCVS components to operate for a period of 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. This power supply will have the capability to use a transfer switch to swap the power supply to the Unit Batteries after 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

Each HCVS will have a corresponding ROS for all three units. This ROS will allow operations personnel to operate the HCVS valves for a sustained period of time.

Each HCVS will have instrumentation and controls to allow operations to monitor and control the HCVS wetwell effluent. The effluent process pressure, temperature and gross radiation levels will be displayed in the Main Control Room of each operating unit. This instrumentation will be designed for expected process conditions for a severe accident event.

The HCVS shall be supplied with a dedicated nitrogen supply capable of operating the HCVS for the desired number of cycles within the first 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

Phase I OIP Page E2-26 of 59 Revision 1 Revision 1 of Tennessee Valley Authoritys 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-13-109)

Part 2: Boundary Conditions for WW Vent: BDBEE Venting Each HCVS discharge pipe will be routed to the Reactor Building roof. As the HCVS piping passes thru the refuel floor roof, a check valve will be designed to prevent the introduction of air to the HCVS piping to mitigate the possible detonation or deflagration of the HCVS piping downstream of the PCIVs.

Key Venting Parameters:

List instrumentation credited for this venting actions. Clearly indicate which of those already exist in the plant and what others will be newly installed (to comply with the vent order)

Initiation, operation and monitoring of the HCVS venting will rely on the following key parameters and indicators:

Key Parameter Component Identifier Indication Location HCVS Effluent Temperature TBD MCR HCVS Pneumatic Supply Pressure TBD ROS HCVS Valve Position Indication TBD MCR HCVS Pressure Indication TBD MCR HCVS Radiation TBD MCR Initiation and operation of the HCVS will rely on several existing Main Control Room key parameters and indicators which are qualified or evaluated to the existing plant design (reference NEI 13-02, Section 4.2.2.1.9):

Key Parameter Component Identifier Indication Location Drywell Pressure TBD MCR Torus Level TBD MCR HCVS indications for HCVS valve position indication, HCVS pneumatic supply pressure, HCVS effluent temperature, and HCVS pressure will be installed in the MCR to comply with EA-13-109.

Notes:

Phase I OIP Page E2-27 of 59 Revision 1 Revision 1 of Tennessee Valley Authoritys 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-13-109)

Part 2: Boundary Conditions for WW Vent: Severe Accident Venting Determine venting capability for Severe Accident Venting, such as may be used in an ELAP scenario to mitigate core damage.

Ref: EA-13-109 Section 1.2.10 / NEI 13-02 Section 2.3 First 24 Hour Coping Detail Provide a general description of the venting actions for first 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> using installed equipment including station modifications that are proposed.

Ref: EA-13-109 Section 1.2.6 / NEI 13-02 Section 2.5, 4.2.2 The operation of the HCVS will be designed to minimize reliance on operator actions for response to an ELAP and severe accident events. A severe accident event assumes that specific core cooling actions from the FLEX strategies identified in the response to Order EA-12-049 were not successfully initiated. Access to the reactor building will be restricted as determined by the RPV water level and core damage conditions. Immediate actions will be completed by Operators in the MCR or at the HCVS ROS and will include remote-manual actions from a local gas cylinder station. The operator actions required to open a vent path were previously listed in the BDBEE Venting Part 2 section of this report (Table 2-1).

Permanently installed power and motive air/gas capable will be available to support operation and monitoring of the HCVS for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. Specifics are the same as for BDBEE Venting Part 2.

System control:

i.

Active: Same as for BDBEE Venting Part 2.

ii.

Passive: Same as for BDBEE Venting Part 2, with no exceptions.

Greater Than 24 Hour Coping Detail Provide a general description of the venting actions for greater than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> using portable and installed equipment including station modifications that are proposed.

Ref: EA-13-109 Section 1.2.4, 1.2.8 / NEI 13-02 Section 4.2.2 Specifics are the same as for BDBEE Venting Part 2 except the location and refueling actions for the FLEX PG and replacement Nitrogen Bottles will be evaluated for SA environmental conditions resulting from the postulated damaged Reactor Core and resultant HCVS vent pathway.

[OIP OPEN ITEM 5]: Perform an Evaluation for FLEX PG 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.

These actions provide long term support for HCVS operation for the period beyond 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to 7 days (sustained operation time period) because on-site and off-site personnel and resources will have access to the unit(s) to provide needed action and supplies.

Phase I OIP Page E2-28 of 59 Revision 1 Revision 1 of Tennessee Valley Authoritys 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-13-109)

Part 2: Boundary Conditions for WW Vent: Severe Accident Venting Details:

Provide a brief description of Procedures / Guidelines:

Confirm that procedure/guidance exists or will be developed to support implementation.

The operation of the HCVS will be governed by the same processes and procedures for SA conditions as for BDBEE conditions. Existing guidance in the SAMGs directs the plant staff to consider changing radiological conditions in a severe accident.

Identify modifications:

List modifications and describe how they support the HCVS Actions.

The same as for BDBEE Venting Part 2, Greater than 24 Hour Coping Details Key Venting Parameters:

List instrumentation credited for the HCVS Actions. Clearly indicate which of those already exist in the plant and what others will be newly installed (to comply with the vent order)

The same as for BDBEE Venting Part 2, Greater than 24 Hour Coping Details Notes:

Phase I OIP Page E2-29 of 59 Revision 1 Revision 1 of Tennessee Valley Authoritys 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-13-109)

Part 2: Boundary Conditions for WW Vent: HCVS Support Equipment Functions Determine venting capability support functions needed Ref: EA-13-109 Section 1.2.8, 1.2.9 / NEI 13-02 Section 2.5, 4.2.4, 6.1.2 BDBEE Venting Provide a general description of the BDBEE Venting actions support functions. Identify methods and strategy(ies) utilized to achieve venting results.

Ref: EA-13-109 Section 1.2.9 / NEI 13-02 Section 2.5, 4.2.2, 4.2.4, 6.1.2 Containment integrity is initially maintained by permanently installed equipment. All containment venting functions will be performed from the MCR or ROS.

Venting will require support from DC power as well as instrument air systems as detailed in the response to Order EA-12-049. Existing safety related Unit Batteries will provide sufficient electrical power for HCVS operation until load shed at approximately 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />. Following load shed the installed HCVS Battery will provide DC power for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. At 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, power will be backed up by FLEX generators supplying power to the Unit Battery chargers. Newly installed nitrogen supply will provide sufficient motive force for all HCVS valve operation and will provide for multiple operations of the HCVS valves.

Severe Accident Venting Provide a general description of the Severe Accident Venting actions support functions. Identify methods and strategy(ies) utilized to achieve venting results.

Ref: EA-13-109 Section 1.2.8, 1.2.9 / NEI 13-02 Section 2.5, 4.2.2, 4.2.4, 6.1.2 The same support functions that are used in the BDBEE scenario would be used for severe accident venting. To ensure power for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, a set of dedicated HCVS batteries will be available to feed HCVS loads via a manual transfer switch. At 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, power will be backed up by FLEX generators supplying power to the Unit Battery chargers for a severe accident HCVS capability.

Nitrogen bottles that will be located in the Diesel Generator building(s) in the immediate area of the ROS will be available to tie-in supplemental pneumatic sources.

Details:

Provide a brief description of Procedures / Guidelines:

Confirm that procedure/guidance exists or will be developed to support implementation.

Most of the equipment used in the HCVS is permanently installed. The key portable items are the severe accident capable portable generators and the nitrogen bottles needed to supplement the air supply to the AOVs after 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. These will be staged in position for the duration of the event.

Phase I OIP Page E2-30 of 59 Revision 1 Revision 1 of Tennessee Valley Authoritys 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-13-109)

Part 2: Boundary Conditions for WW Vent: HCVS Support Equipment Functions Identify modifications:

List modifications and describe how they support the HCVS Actions.

Flex modifications applicable to HCVS operation: The same for BDBEE Venting, Part 2.

HCVS modification: add piping and connection points at a suitable location in the control building or outside to connect portable N2 bottles for motive force to HCVS components after 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. HCVS connections required for portable equipment will be protected from all applicable screened-in hazards and located such that operator exposure to radiation and occupational hazards will be minimized.

Structures to provide protection of the HCVS connections will be constructed to meet the requirements identified in NEI 12-06 Section 11 for screened in hazards.

Key Support Equipment Parameters:

List instrumentation credited for the support equipment utilized in the venting operation. Clearly indicate which of those already exist in the plant and what others will be newly installed (to comply with the vent order)

Local control features of the FLEX portable generator electrical load and fuel supply.

Pressure gauge on supplemental Nitrogen bottles.

Notes:

Phase I OIP Page E2-31 of 59 Revision 1 Revision 1 of Tennessee Valley Authoritys 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-13-109)

Part 2: Boundary Conditions for WW Vent: HCVS Venting Portable Equipment Deployment Provide a general description of the venting actions using portable equipment including modifications that are proposed to maintain and/or support safety functions.

Ref: EA-13-109 Section 3.1 / NEI 13-02 Section 6.1.2, D.1.3.1 Deployment pathways for compliance with Order EA-12-049 are acceptable without further evaluation needed except in areas around the Reactor Building or in the vicinity of the HCVS piping. Deployment in the areas around the Reactor Building or in the vicinity of the HCVS piping will allow access, operation and replenishment of consumables with the consideration that there is potential reactor core damage and HCVS operation.

Details:

Provide a brief description of Procedures / Guidelines:

Confirm that procedure/guidance exists or will be developed to support implementation.

Operation of the portable equipment is the same as for compliance with Order EA-12-049 thus they are acceptable without further evaluation HCVS Actions Modifications Protection of connections Identify Actions including how the equipment will be deployed to the point of use.

Identify modifications Identify how the connection is protected Per compliance with Order EA-12-049 (FLEX)

N/A Per compliance with Order EA 049 (FLEX)

Notes:

Phase I OIP Page E2-32 of 59 Revision 1 Revision 1 of Tennessee Valley Authoritys 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-13-109)

Part 3: Boundary Conditions for Dry Well Vent Provide a sequence of events and identify any time constraint required for success including the basis for the time constraint.

HCVS Actions that have a time constraint to be successful should be identified with a technical basis and a justification provided that the time can reasonably be met (for example, a walk-through of deployment).

Describe in detail in this section the technical basis for the time constraint identified on the sequence of events timeline Attachment 2B See attached sequence of events timeline (Attachment 2B).

Ref: EA-13-109 Section X.X.X / NEI 13-02 Section X.X.x Part 3 will be completed with Order EA-13-109, Phase 2 OIP submittal by December 31, 2015 Severe Accident Venting Determine venting capability for Severe Accident Venting, such as may be used in an ELAP scenario to mitigate core damage.

Ref: EA-13-109 Section X.X.X / NEI 13-02 Section X.X.x First 24 Hour Coping Detail Provide a general description of the venting actions for first 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> using installed equipment including station modifications that are proposed.

Ref: EA-13-109 Section X.X.X / NEI 13-02 Section X.X.x Greater Than 24 Hour Coping Detail Provide a general description of the venting actions for greater than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> using portable and installed equipment including station modifications that are proposed.

Ref: EA-13-109 Section X.X.X / NEI 13-02 Section X.X.x Details:

Provide a brief description of Procedures / Guidelines:

Confirm that procedure/guidance exists or will be developed to support implementation.

Phase I OIP Page E2-33 of 59 Revision 1 Revision 1 of Tennessee Valley Authoritys 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-13-109)

Part 3: Boundary Conditions for Dry Well Vent Identify modifications:

List modifications and describe how they support the HCVS Actions.

Key Venting Parameters:

List instrumentation credited for the venting HCVS Actions.

Notes:

Phase I OIP Page E2-34 of 59 Revision 1 Revision 1 of Tennessee Valley Authoritys 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-13-109)

Part 4: Programmatic Controls, Training, Drills and Maintenance Identify how the programmatic controls will be met.

Provide a description of the programmatic controls equipment protection, storage and deployment and equipment quality addressing the impact of temperature and environment Ref: EA-13-109 Section 3.1, 3.2 / NEI 13-02 Section 6.1.2, 6.1.3, 6.2 Program Controls:

The HCVS venting actions will include:

Site procedures and programs are being developed in accordance with NEI 13-02 to address use and storage of portable equipment relative to the Severe Accident defined in NRC Order EA-13-109 and the hazards applicable to the site per Part 1 of this OIP.

Routes for transporting portable equipment from storage location(s) to deployment areas will be developed as the response details are identified and finalized. The identified paths and deployment areas will be accessible during all modes of operation and during severe accidents.

Procedures:

Procedures will be established for system operation when normal and backup power is available, and during ELAP conditions.

The HCVS procedures will be developed and implemented following the sites process for initiating or revising procedures and will contain the following details:

appropriate conditions and criteria for use of the HCVS, when and how to place the HCVS in operation, the location of system components, instrumentation available, normal and backup power supplies, directions for sustained operation, including the storage location of portable equipment, training on operating the portable equipment, and testing of portable equipment.

BFN utilizes CAP for ECCS pump NPSH. The BFN procedures already provide guidance to state that Reducing Primary Containment pressure will reduce the available NPSH for pumps taking suction from the suppression pool.

BFN will establish provisions for out-of-service requirements of the HCVS and compensatory measures. The following provisions will be documented in OPDP-8 Operability Determination Process and Limiting Conditions for Operations Tracking (Reference 37):

The provisions for out-of-service requirements for HCVS functionality are applicable in Modes 1, 2, and 3.

If for up to 90 consecutive days, the primary or alternate means of HCVS operation are non-functional, no compensatory actions are necessary.

Phase I OIP Page E2-35 of 59 Revision 1 Revision 1 of Tennessee Valley Authoritys 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-13-109)

Part 4: Programmatic Controls, Training, Drills and Maintenance If for up to 30 days, the primary and alternate means of HCVS operation are non-functional, no compensatory actions are necessary.

If the out of service times exceed 30 or 90 days as described above, the following actions will be performed:

o The condition will be entered into the corrective action system o The HCVS functionality will be restored in a manner consistent with plant procedures o A cause assessment will be performed to prevent future loss of function for similar causes.

o Initiate action to implement appropriate compensatory actions.

Describe training plan List training plans for affected organizations or describe the plan for training development Ref: EA-13-109 Section 3.2 / NEI 13-02 Section 6.1.3 Personnel expected to perform direct execution of the HVCS will receive necessary training in the use of plant procedures for system operations when normal and backup power is available and during ELAP conditions. The training will be refreshed on a periodic basis and as any changes occur to the HCVS. Training content and frequency will be established using the Systematic Approach to Training (SAT) process.

In addition, all personnel on-site will be available to supplement trained personnel (Reference NEI 12-06).

Identify how the drills and exercise parameters will be met.

Alignment with NEI 13-06 and 14-01as codified in NTTF Recommendation 8 and 9 rulemaking The Licensee should demonstrate use of the HCVS in drills, tabletops, or exercises as follows:

Hardened containment vent operation on normal power sources (no ELAP).

During FLEX demonstrations (as required by EA-12-049: Hardened containment vent operation on backup power and from primary or alternate location during conditions of ELAP/loss of UHS with no core damage. System use is for containment heat removal AND containment pressure control.

HCVS operation on backup power and from primary or alternate location during conditions of ELAP/loss of UHS with core damage. System use is for containment heat removal AND containment pressure control with potential for combustible gases (demonstration may be in conjunction with SAG change).

Ref: EA-13-109 Section 3.1 / NEI 13-02 Section 6.1.3 Phase I OIP Page E2-36 of 59 Revision 1 Revision 1 of Tennessee Valley Authoritys 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-13-109)

Part 4: Programmatic Controls, Training, Drills and Maintenance The site will utilize the guidance provided in NEI 13-06 and 14-01 for guidance related to drills, tabletops, or exercises for HCVS operation. In addition, the site will integrate these requirements with compliance to any rulemaking resulting from the NTTF Recommendations 8 and 9.

Describe maintenance plan:

The HCVS maintenance program should ensure that the HCVS equipment reliability is being achieved in a manner similar to that required for FLEX equipment. Standard industry templates (e.g. EPRI) and associated bases may be developed to define specific maintenance and testing.

o Periodic testing and frequency should be determined based on equipment type, expected use and manufacturers recommendations (further details are provided in Section 6 of this document).

o Testing should be done to verify design requirements and/or basis. The basis should be documented and deviations from vendor recommendations and applicable standards should be justified.

o Preventive maintenance should be determined based on equipment type and expected use. The basis should be documented and deviations from vendor recommendations and applicable standards should be justified.

o Existing work control processes may be used to control maintenance and testing.

HCVS permanent installed equipment should be maintained in a manner that is consistent with assuring that it performs its function when required.

o HCVS permanently installed equipment should be subject to maintenance and testing guidance provided to verify proper function.

HCVS non-installed equipment should be stored and maintained in a manner that is consistent with assuring that it does not degrade over long periods of storage and that it is accessible for periodic maintenance and testing.

Ref: EA-13-109 Section 1.2.13 / NEI 13-02 Section 5.4, 6.2 The site will utilize the standard EPRI industry preventative maintenance (PM) process (Similar to the Preventive Maintenance Basis Database) for establishing the maintenance calibration and testing actions for HCVS components. The control program will include maintenance guidance, testing procedures and frequencies established based on type of equipment and considerations made within the EPRI guidelines.

BFN will implement the following operation, testing and inspection requirements for the HCVS to ensure reliable operation of the system.

Phase I OIP Page E2-37 of 59 Revision 1 Revision 1 of Tennessee Valley Authoritys 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-13-109)

Part 4: Programmatic Controls, Training, Drills and Maintenance Table 4-1: Testing and Inspection Requirements Description Frequency Cycle the HCVS and installed SAWA valves 1 and the interfacing system boundary valves not used to maintain containment integrity during Mode 1, 2 and

3. For HCVS valves, this test may be performed concurrently with the control logic test described below.

Once per every 2 operating cycle Cycle the HCVS and installed SAWA check valves not used to maintain containment integrity during unit operations 3.

Once per every other 4 operating cycle Perform visual inspections and a walk down of HCVS and installed SAWA components.

Once per operating cycle Functionally test the HCVS radiation monitors.

Once per operating cycle Leak test the HCVS (as described in Section 6.2.2 and 6.2.3).

(1) Prior to first declaring the system functional; (2) Once every three operating cycles thereafter; and, (3) After restoration of any breach of system boundary within buildings.

Validate the HCVS operating procedures by conducting an open/close test of the HCVS control function from its control location and ensuring that all HCVS vent path and interfacing system boundary valves 5 move to their proper (intended) positions.

Once per every other operating cycle Notes:

1 Not required for HCVS and Severe Accident Water Addition (SAWA) check valves.

2 After two consecutive successful performances, the test frequency may be reduced to a maximum of once per every other operating cycle.

3 Not required if integrity of check function (open and closed) is demonstrated by other plant testing requirements.

4After two consecutive successful performances, the test frequency may be reduced by one Phase I OIP Page E2-38 of 59 Revision 1 Revision 1 of Tennessee Valley Authoritys 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-13-109)

Part 4: Programmatic Controls, Training, Drills and Maintenance operating cycle to a maximum of once per every fourth operating cycle.

5 Interfacing system boundary valves that are normally closed and fail closed under ELAP conditions (loss of power and/or air) do not require control function testing under this section. Performing existing plant design basis function testing or system operation that reposition the valve(s) to the HCVS required position will meet this requirement without the need for additional testing.

Phase I OIP Page E2-39 of 59 Revision 1 Revision 1 of Tennessee Valley Authoritys 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-13-109)

Part 5: Milestone Schedule Provide a milestone schedule. This schedule should include:

Modifications timeline Procedure guidance development complete o

HCVS Actions o

Maintenance Storage plan (reasonable protection)

Staffing analysis completion Long term use equipment acquisition timeline Training completion for the HCVS Actions The dates specifically required by the order are obligated or committed dates. Other dates are planned dates subject to change. Updates will be provided in the periodic (six month) status reports.

Ref: EA-13-109 Section D.1, D.3 / NEI 13-02 Section 7.2.1 The following milestone schedule is provided. The dates are planning dates subject to change as design and implementation details are developed. Any changes to the following target dates will be reflected in the subsequent 6 month status reports.

Milestone Target Completion Date Activity Status Comments

{Include date changes in this column}

Hold preliminary/conceptual design meeting Jun 2014 Complete Submit Overall Integrated Implementation Plan Jun 2014 Complete Submit 6 Month Status Report Dec 2014 Complete Submit 6 Month Status Report Jun. 2015 Complete with this submittal Submit 6 Month Status Report Dec 2015 Simultaneous with Phase 2 OIP U1 Design Engineering On-site/Complete Jan 2016 Started Submit 6 Month Status Report Jun 2016 Operations Procedure Changes Developed Jul 2016 Site Specific Maintenance Procedure Developed Jul 2016 Submit 6 Month Status Report Dec 2016 Training Complete Sep 2016 U1 Implementation Outage Nov 2016 Procedure Changes Active Nov 2016 U1 Walk Through Demonstration/Functional Test Nov 2016 U2 Design Engineering On-site/Complete Jun 2016 Phase I OIP Page E2-40 of 59 Revision 1 Revision 1 of Tennessee Valley Authoritys 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-13-109)

Part 5: Milestone Schedule U2 Implementation Outage Mar 2017 U2 Walk Through Demonstration/Functional Test Apr 2017 Submit 6 Month Status Report Jun 2017 Submit 6 Month Status Report Dec 2017 Submit 6 Month Status Report Jun 2017 U3 Design Engineering On-site/Complete Jul 2017 U3 Implementation Outage Mar 2018 U3 Walk Through Demonstration/Functional Test Apr 2018 Submit Completion Report Jun 2018 Phase I OIP Page E2-41 of 59 Revision 1 Revision 1 of Tennessee Valley Authoritys 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-13-109) : HCVS Portable Equipment List portable equipment BDBEE Venting Severe Accident Venting Performance Criteria Maintenance / PM requirements FLEX Portable Generators X

X TBD Per Response to EA-12-049 Nitrogen Cylinders X

X TBD Check periodically for pressure, replace or replenish as needed Phase I OIP Page E2-42 of 59 Revision 1 Revision 1 of Tennessee Valley Authoritys 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-13-109) : Sequence of Events Timeline Table 2A: Wet Well HCVS Timeline HCVS Phase I - Overall Integrated Plan Template BFN Sequence of Events Timeline - Attachment 2 SBO t=0s RCIC starts t.5 m t 6 hrs No Injection Legend Adequate core cooling maintained Injection Lost Increased shine and leakage of radionuclides primarily from Wetwell HCVS Post Core Damage Dose Evaluation Required Level at TAF t 22 hrs Anticipatory Venting Not to scale t 18 hrs No Injection t 23 hrs t 34 hrs t 1 hr t8 hr Containment Venting (based on exceeding PCPL)

Case 1 FLEX successful BFNP Case 2 RCIC Late Failure Ref: SECY-12-0157 Case 3 RCIC Early Failure Ref: SOARCA

References:

Case 1: Reference Plant FLEX Overall Integrated Plan Case 2: SECY-12-0157 - ML12344A030 Case 3: SOARCA - ML13150A053 Portable generator providing power to Safety Related 480VAC System (Ref Plant OIP) t 8 hr t 24 hrs Replenishment of HCVS power and pneumatic supplies t 24 hrs Phase I OIP Page E2-43 of 59 Revision 1 Revision 1 of Tennessee Valley Authoritys 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-13-109) : Conceptual Sketches Phase I OIP Page E2-44 of 59 Revision 1 Revision 1 of Tennessee Valley Authoritys 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-13-109)

Figure 2 - Mechanical I&C Flow Diagram Control Air System Phase I OIP Page E2-45 of 59 Revision 1 Revision 1 of Tennessee Valley Authoritys 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-13-109)

Phase I OIP Page E2-46 of 59 Revision 1 Revision 1 of Tennessee Valley Authoritys 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-13-109)

Phase I OIP Page E2-47 of 59 Revision 1 Revision 1 of Tennessee Valley Authoritys 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-13-109)

Phase I OIP Page E2-48 of 59 Revision 1 Revision 1 of Tennessee Valley Authoritys 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-13-109)

Phase I OIP Page E2-49 of 59 Revision 1 Revision 1 of Tennessee Valley Authoritys 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-13-109)

Phase I OIP Page E2-50 of 59 Revision 1 Revision 1 of Tennessee Valley Authoritys 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-13-109) : Failure Evaluation Table Table 4A: Wet Well HCVS Failure Evaluation Table Functional Failure Mode Failure Cause Alternate Action Failure with Alternate Action Impact on Containment Venting?

Failure of Vent to Open on Demand Valves fail to open/close due to loss of normal AC power No action needed, power is already tied into Unit Battery for 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> maximum No Failure of Vent to Open on Demand Valves fail to open/close due to loss of normal DC power (long term)

Connect dedicated batteries via transfer switch for minimum 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> No Failure of Vent to Open on Demand Valves fail to open/close due to complete loss of batteries (long term)

Recharge Unit Batteries with FLEX provided generators, considering severe accident conditions No Failure of Vent to Open on Demand Valves fail to open/close due to loss of normal pneumatic air supply No action needed, N2 can be supplied by accumulator tanks, which is sufficient for at least 12 cycles of F082 valve over first 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

No Failure of Vent to Open on Demand Valves fail to open/close due to loss of alternate pneumatic air supply (long term)

Tie-in nitrogen cylinders to N2 system supporting HCVS valves, replace bottles as needed.

No Failure of Vent to Open on Demand Valves fail to open/close due to SOV failure Use nitrogen supply from the ROS that is located in the Diesel Generator Building.

No Phase I OIP Page E2-51 of 59 Revision 1 Revision 1 of Tennessee Valley Authoritys 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-13-109) : References

1. Generic Letter 89-16, Installation of a Hardened Wetwell Vent, dated September 1, 1989

2. Order EA-12-049, Mitigation Strategies for Beyond-Design-Basis External Events, dated March 12, 2012

3. Order EA-12-050, Reliable Hardened Containment Vents, dated March 12, 2012

4. Order EA-12-051, Reliable SFP Level Instrumentation, dated March 12, 2012

5. Order EA-13-109, Severe Accident Reliable Hardened Containment Vents, dated June 6, 2013

6. JLD-ISG-2012-01, Compliance with Order EA-12-049, Mitigation Strategies for Beyond-Design-Basis External Events, dated August 29, 2012

7. JLD-ISG-2012-02, Compliance with Order EA-12-050, Reliable Hardened Containment Vents, dated August 29, 2012

8. JLD-ISG-2013-02, Compliance with Order EA-13-109, Severe Accident Reliable Hardened Containment Vents, dated November 14, 2013

9. NRC Responses to Public Comments, Japan Lessons-Learned Project Directorate Interim Staff Guidance JLD-ISG-2012-02:

Compliance with Order EA-12-050, Order Modifying Licenses with Regard to Reliable Hardened Containment Vents, ADAMS Accession No. ML12229A477, dated August 29, 2012

10. NEI 12-06, Diverse and Flexible Coping Strategies (FLEX) Implementation Guide, Revision 1, dated August 2012

11. NEI 13-02, Industry Guidance for Compliance with Order EA-13-109, Revision 0, Dated November 2013

12. NEI 13-06, Enhancements to Emergency Response Capabilities for Beyond Design Basis Accidents and Events, Revision 0, dated March 2014

13. NEI 14-01, Emergency Response Procedures and Guidelines for Extreme Events and Severe Accidents, Revision 0, dated March 2014

14. NEI FAQ HCVS-01, HCVS Primary Controls and Alternate Controls and Monitoring Locations

15. NEI FAQ HCVS-02, HCVS Dedicated Equipment

16. NEI FAQ HCVS-03, HCVS Alternate Control Operating Mechanisms

17. NEI FAQ HCVS-04, HCVS Release Point

18. NEI FAQ HCVS-05, HCVS Control and Boundary Valves

19. NEI FAQ HCVS-06, FLEX Assumptions/HCVS Generic Assumptions

20. NEI FAQ HCVS-07, Consideration of Release from Spent Fuel Pool Anomalies

21. NEI FAQ HCVS-08, HCVS Instrument Qualifications

22. NEI FAQ HCVS-09, Use of Toolbox Actions for Personnel

23. NEI White Paper HCVS-WP-01, HCVS Dedicated Power and Motive Force

24. NEI White Paper HCVS-WP-02, HCVS Cyclic Operations Approach

25. NEI White Paper HCVS-WP-03, Hydrogen/CO Control Measures Phase I OIP Page E2-52 of 59 Revision 1 Revision 1 of Tennessee Valley Authoritys 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-13-109)

26. NEI White Paper HCVS-WP-04, FLEX/HCVS Interactions

27. IEEE Standard 344-2004, IEEE Recommended Practice for Seismic Qualification of Class 1E Equipment for Nuclear Power Generating Stations,

28. BFN EA-12-049 (FLEX) Overall Integrated Implementation Plan, Rev 0, February 2013

29. BFN EA-12-050 (HCVS) Overall Integrated Implementation Plan, Rev 0, February 2013

30. BFN EA-12-051 (SFP LI) Overall Integrated Implementation Plan, Rev 0, February 2013

31. BFN Calculation MDN0999980114 Rev 3 Station Blackout Evaluation

32. BFN Calculation EDQ0009992013000202 Rev 0 250V DC UNIT BATTERIES 1,2 & 3 EVALUATION

33. BFN Design Criteria BFN-50-C-7101 Rev 03 "Protection from wind, tornado wind, tornado depressurization, tornado generated missiles, and external flooding

34. BFN Procedure 1/2/3-EOI-2, Primary Containment Control

35. BFN Design Criteria: BFN-50-7360 FLEX MITIGATION SYSTEM

36. TVA Calculation MDQ0003602014000222 BFN ELAP Transient Temperature Analysis

37. TVA OPDP-8 Operability Determination Process and Limiting Conditions for Operation Tracking Revision 18.

38. 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-13-109 (Severe Accident Capable Hardened Vents) (TAC NOS. MF4540, MF4541 and MF4542)

Phase I OIP Page E2-53 of 59 Revision 1 Revision 1 of Tennessee Valley Authoritys 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-13-109) :

Changes/Updates to this Overall Integrated Implementation Plan Any significant changes to this plan will be communicated to the NRC staff in the 6 Month Status Reports None.

Phase I OIP Page E2-54 of 59 Revision 1 Revision 1 of Tennessee Valley Authoritys 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-13-109) : List of Overall Integrated Plan and Interim Staff Evaluation (ISE) Open Items Overall Integrated Plan Phase 1 Open Item Status 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.

Open 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.

Open 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.

Open 4

Revise 1/2/3-EOI Appendix 13 to include venting for loss of DC power.

Open 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.

Open 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 - Calculation EDQ0009992013000202 Rev 1 has been issued to determine load shedding impact on the unit batteries.

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

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

Phase I OIP Page E2-55 of 59 Revision 1 Revision 1 of Tennessee Valley Authoritys 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-13-109)

Overall Integrated Plan Phase 1 Open Item Status 8 The wetwell vent will be designed to remove 1% of rated thermal power at EPU conditions.

Closed - The existing wetwell vent (CLTP) and the HCVS (EPU) has been designed for 1% of rated thermal power at EPU conditions 9 Implement the Harris Radio System for communication between the MCR and the ROS.

Revised - A communication system will be used that uses hand held radios for communication between the main control room and the remote operating station.

Phase I OIP Page E2-56 of 59 Revision 1 Revision 1 of Tennessee Valley Authoritys 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-13-109)

Interim Staff Evaluation Phase 1 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.

In Progress 2

Make available for NRC audit documentation that procedure 1/2/3-EOI Appendix 13 to has been revised to include venting for loss of dc power.

In Progess 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 Rev 1 has been issued to determine load shedding impact on the unit batteries.

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.

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) has been designed for 1% of rated thermal power at EPU conditions.

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.

In Progress Phase I OIP Page E2-57 of 59 Revision 1 Revision 1 of Tennessee Valley Authoritys 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-13-109)

Interim Staff Evaluation Phase 1 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.

In Progress 8

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

In Progress 9

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

In Progress 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.

In Progress 11 Make available for NRC staff audit the final sizing evaluation for HCVS batteries/battery charger including incorporation into FLEX DG loading calculation.

In Progress 12 Make available for NRC staff audit documentation of the HCVS nitrogen pneumatic system design including sizing and location In Progress 13 Make available for NRC staff audit the seismic and tornado missile final design criteria for the HCVS stack.

In Progress Phase I OIP Page E2-58 of 59 Revision 1 Revision 1 of Tennessee Valley Authoritys 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-13-109)

Interim Staff Evaluation Phase 1 Open Item Status 14 Provide a description of the final design of the HCVS to address hydrogen detonation and deflagration.

In Progress 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.

In Progress 16 Provide design details that minimize unintended cross flow of vented fluids within a unit and between units on the site.

In Progress Phase I OIP Page E2-59 of 59 Revision 1