ML15170A333

Six-Month Status Report in Response to June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number EA-13-109)

ML15170A333
Person / Time
Site:	Duane Arnold
Issue date:	06/18/2015
From:	Vehec T A NextEra Energy Duane Arnold
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
EA-13-109, NG-15-0169
Download: ML15170A333 (10)

Text

NEXTera ENERG-1-ý;ýARNOLD NG-1 5-0169 June 18, 2015 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Duane Arnold Energy Center Docket No. 50-331 Renewed Facility Operating License No. DPR-49 NextEra Energy Duane Arnold, LLC's Six-Month Status Report in Response to June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number EA-13-109

References:

1. Order EA-13-109, "Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions," dated June 6, 2013 (ML13130A067)

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," dated November 14, 2013 (ML13304B836)

3. NRC Endorsement of Industry "Hardened Containment Venting (HCVS) Phase 1 Overall Integrated Plan Template (EA-13-109)

Rev 0," (ML14128A219)

4. NEI 13-02, "Industry Guidance for Compliance with Order EA-13-109, Revision 0," dated November 2013 5. NextEra Energy Duane Arnold LLC's Phase 1 Overall Integrated Plan in Response to June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number EA-13-109, dated December 10, 2014 (ML14349A324)

On June 6, 2013, the Nuclear Regulatory Commission

("NRC" or "Commission")

issued an order (Reference

1) to NextEra Energy Duane Arnold, LLC. Reference 1 was immediately effective and directs NextEra Energy Duane Arnold, LLC (hereafter NextEra Energy Duane Arnold) to install a reliable hardened venting capability for pre-core damage and under severe accident conditions, including those involving a breach of the reactor vessel by molten core debris. Specific requirements are outlined in Attachment 2 of Reference

1. Al 51ý-Ipz NextEra Energy Duane Arnold, LLC, 3277 DAEC Road, Palo, IA 52324 Document Control Desk NG-1 5-0169 Page 2 of 2 Reference 1 required submission of a phase 1 overall integrated plan pursuant to Section IV, Condition D. Reference 2 endorses industry guidance document NEI 13-02, Revision 0 (Reference

4) with clarifications and exceptions identified in Reference 2.Reference 5 provided the NextEra Energy Duane Arnold LLC overall integrated plan.Reference 1 requires submission of a status report at six-month intervals following submittal of the overall integrated plan. Reference 2 (and 4) provides direction regarding the content of the status reports. The purpose of this letter is to provide the six-month status report pursuant to Section IV, Condition D, of Reference 1, that delineates progress made in implementing the requirements of Reference

1. The enclosed report provides an update of milestone accomplishments since the last status report, including any changes to the compliance method, schedule, or need for relief and the basis, if any.This letter contains no new regulatory commitments, however, there are several updates to design detail since the submittal of Reference 5.If you have any questions regarding this report, please contact Ken Putnam at 319-851-7238.I declare under penalty of perjury that the foregoing is true and correct.e oJune 18, 2015.T. A. Vehec Vice President, Duane Arnold Energy Center NextEra Energy Duane Arnold, LLC Enclosure cc: Director, Office of Nuclear Reactor Regulation USNRC Regional Administrator Region III USNRC Project Manager, Duane Arnold Energy Center USNRC Resident Inspector, Duane Arnold Energy Center Enclosure to NG-15-0169 NextEra Enerqy Duane Arnold, LLC's Six-Month Status Report in Response to June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number EA-13-109) 7 pages follow NextEra Energy Duane Arnold LLC's Six Month Status Report in Response to June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number 13-109)Introduction NextEra Duane Arnold Energy Center, LLC developed an Overall Integrated Plan (Reference 1 on page 3), 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

2. This attachment provides an update of milestone accomplishments since submittal of the Phase 1 Overall Integrated Plan, including any changes to the compliance method, schedule, or need for relief/relaxation and the basis, if any.Milestone Accomplishments The following milestone(s) have been completed since the development of the Overall Integrated Plan (Reference 1), and are current as of June 1, 2015: " Initial Outage for Phase 1 Planning" Submit Six Month Status Reports Milestone Schedule Status The following provides an update to Part 5 of the Overall Integrated Plan. It provides the activity status of each item, and whether the expected completion date has changed. The dates are planning dates subject to change as design and implementation details are developed.

There are no changes to the current target dates in the Overall Integrated Plan at this time.Target Activity Comments/Milestone Completion Status Date Changes Date SttsaeChne Phase I HCVS Milestone Table Issue preliminary/conceptual design report Jun 2014 Complete Submit Overall Integrated Implementation Jun 2014 Complete Plan Initial Outage for Phase 1 Planning Nov 2014 Complete Submit 6 Month Status Report Dec 2014 Complete Submit 6 Month Status Report Jun 2015 Complete Submit 6 Month Status Report Dec 2015 Not Started Design Complete Phase 1 Mar 2016 Started Submit 6 Month Status Report Jun 2016 Not Started Operations Procedure Changes Oct 2016 Not Started Developed Phase 1 Page 1 of 7 NextEra Energy Duane Arnold LLC's Six Month Status Report in Response to June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number 13-109)Target Activity Comments/Milestone Completion Status Date Changes Date Phase 1 HCVS Milestone Table Site Specific Maintenance and Testing Oct 2016 Not Started Procedures Developed Phase 1 Training Complete Phase 1 Oct 2016 Not Started Implementation Outage Phase 1 End of Not Started RF025 Procedure Changes Active Phase 1 End of Not Started RF025 Walk Through Demonstration/Functional End of Not Started Test Phase 1 RF025 Submit Completion Report 60 days Not Started after RF025 Changes to Compliance Method There are several updates to the design detail since the previous submittal in December 2014 resulting in the following changes to the compliance method: 1) The location of the Remote Operating Station (ROS) has moved from the 1A4 Essential Switchgear Room in the Control Building to outside the 1A3 Essential Switchgear Room in the Turbine Building.2) The routing of the new containment hardened vent system (HCVS) piping has changed from utilizing an existing containment penetration that supports normal venting to the Standby Gas Treatment System to using an existing spare penetration off the suppression pool. The vent piping will be routed into the south reactor building stairwell, up to the refuel floor and out the reactor building roof, reference Attachment A.3) The HCVS piping will contain two new primary containment isolation valves and a new rupture disk as shown in Attachment A.4) Attachment B is an updated listing of the HCVS instrumentation.

It should be noted that the Interim Staff Evaluation (ISE) inadvertently listed a vent pipe process pressure indicator which will not be part of the Duane Arnold design.Need for Relief/Relaxation and Basis for the Relief/Relaxation NextEra Duane Arnold Energy Center, LLC expects to comply with the order implementation date and no relief/relaxation is required at this time.Page 2 of 7 NextEra Energy Duane Arnold LLC's Six Month Status Report in Response to June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number 13-109)Open Items from Overall Integrated Plan and Interim Staff Evaluation The following tables provide a summary of the open items documented in the Phase 1 Overall Integrated Plan or the Interim Staff Evaluation (ISE) and the status of each item.Overall Integrated Plan Phase 1 Open Item Status Confirm secondary containment bypass leakage is Started acceptable without an installed rupture disk or retain an appropriated disk Perform severe accident evaluation for FLEX DG and Started replacement gas to confirm accessibility for use for post 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> actions Evaluate tornado/missile effects on HCVS components Started above the protected area of the Reactor Building Evaluate the system design for H2/CO measures to be taken Started Interim Staff Evaluation Open Item Status Make available for NRC staff audit documentation of Started licensee confirmation that secondary containment leakage is acceptable without an installed rupture disk or that an appropriate rupture disk, including procedures for rupture during HCVS operation, is included in the HCVS design.Make available for NRC staff audit analyses demonstrating Started that HCVS has the capacity to vent the steam/energy equivalent of one (1) 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.Make available for NRC staff audit evaluations of tornado Started missile effects on HCVS components above the protected area of the reactor building.Make available for NRC staff audit additional detail on the Started design features that minimize unintended cross flow of vented fluids within a unit, including a one line diagram containing sufficient detail to confirm the description in the OIP.Page 3 of 7 NextEra Energy Duane Arnold LLC's Six Month Status Report in Response to June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number 13-109)Interim Staff Evaluation Open Item Status Provide a description of the final design of the HCVS to Started address hydrogen detonation and deflagration.

Provide a description.

of the strategies for hydrogen control Started that minimizes the potential for hydrogen gas migration and ingress into the reactor building or other buildings.

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

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

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

Make available for NRC staff audit the final sizing evaluation Started for pneumatic N2 supply.Make available for NRC staff audit documentation of an Eliminated evaluation verifying the existing containment isolation (See Note 1)valves, relied upon for the HCVS, will open under the maximum expected differential pressure during BDBEE and.severe accident wetwell venting.Make available for NRC staff audit descriptions of all Started instrumentation and controls (existing and planned)necessary to implement this order including qualification methods.Make available for NRC staff audit the descriptions of local Started 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.

Provide a justification for deviating from the instrumentation Eliminated seismic qualification guidance specified in NEI13-02, (See Note 2)endorsed, in part, by JLD-ISG-2013-02 as an acceptable means for implementing applicable requirements of Order EA-13-109.

Page 4 of 7 NextEra Energy Duane Arnold LLC's Six Month Status Report in Response to June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number 13-109)Note 1: Due to design changes in vent location and routing, existing containment isolation valves will no longer be used for venting. New vent design will utilize a spare torus penetration with two new primary containment isolation valves and a rupture disk.Note 2: The qualification method used for each HCVS instrument will be to the IEEE 344-2004 standard or a substantially similar industrial standard and therefore will not be deviating from NEI 13-02 or JLD-ISG-2013-02.

Interim Staff Evaluation Impacts There are two potential impacts to the Interim Staff Evaluation identified at this time: 1) One ISE Open Item will be eliminated because the Hardened Pipe Vent will no longer use existinq containment isolation valves. The revised vent pipe routing will instead use an existing spare torus penetration and install two new containment isolation valves and a rupture disk. An evaluation will be done to ensure the two new containment isolation valves will open under the maximum expected differential pressure during BDBEE and severe accident wetwell venting.2) It should be noted that the Interim Staff Evaluation (ISE) inadvertently listed a vent pipe process pressure indicator which will not be part of the Duane Arnold design.References The following references support the updates to the Phase 1 Overall Integrated Plan described in this Enclosure.

1. NextEra Duane Arnold Energy Center, LLC's Phase 1 Overall Integrated Plan in Response to June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number EA-13-109)," dated June 25, 2014 (ML14182A423).

2. NRC Order Number EA-13-109, "Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions" dated June 6, 2013 (ML13130A067).

3. NEI 13-02, "Industry Guidance for Compliance with NRC Order EA-13-109, Revision 0," dated November 2013.4. 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).

5. NRC Endorsement of industry "Hardened Containment Venting System (HCVS)Phase 1 Overall Integrated Plan Template (EA-13-109)

Rev 0" (ML14128A219).

Page 5 of 7 NextEra Energy Duane Arnold LLC's Six Month Status Report in Response to June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number 13-109)Attachment A -Updated Layout of Proposed HCVS z Ir-- I O.O cc 0]w..-w h-J° D 00 TT a: 0 0 M Page 6 of 7 NextEra Energy Duane Arnold LLC's Six Month Status Report in Response to June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number 13-109)Attachment B -HCVS Indication Instruments Instrument Indication Parameter New/ Existing Location Function HCVS System New MCR Provides indication of open vent path.Effluent Installed in MCR to comply with EA-Temperature 13-109.HCVS New ROS Provides an indication of compressed Pneumatic gas to determine when bottle(s) need Supply to be replaced to ensure pressure is Pressure adequate to operate two PCIVs (multiple cycles), blow the rupture disk for vent use and for purging the vent line to prevent hydrogen detonation.

Installed locally at the ROS to comply with EA-13-109.

HCVS System New MCR Provides operators a position Valve Position indication for each PCIV using lights Indication to comply with EA-13-109.

HCVS System New MCR Provides indication of order of Radiation magnitude of radiation and indication Monitor of open vent path.HCVS UPS New ROS Provides indication of UPS voltage Status status.Indication Compressed New MCR & ROS Provides compressed gas volume Gas Flow indication.

Totalizer Torus Air Existing MCR 1C03 Provides indication of Torus Pressure -Pressure.P14395A/B (0-100 psig) I Page 7 of 7