ML15170A333

Duane Arnold - 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

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

References:

1. Order EA-13-109, "Order Modifying Licenses with Regard toReliable Hardened Containment Vents Capable of Operation UnderSevere Accident Conditions,"

dated June 6, 2013 (ML13130A067)

2. NRC Interim Staff Guidance JLD-ISG-2013-02, "Compliance withOrder EA-13-109, Order Modifying Licenses with Regard to ReliableHardened Containment Vents Capable of Operation Under SevereAccident Conditions,"

dated November 14, 2013 (ML13304B836)

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

Rev0," (ML14128A219)

4. NEI 13-02, "Industry Guidance for Compliance with Order EA-13-109, Revision 0," dated November 20135. 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 VentsCapable of Operation Under Severe Accident Conditions (OrderNumber EA-13-109, dated December 10, 2014 (ML14349A324)

On June 6, 2013, the Nuclear Regulatory Commission

("NRC" or "Commission")

issuedan order (Reference

1) to NextEra Energy Duane Arnold, LLC. Reference 1 wasimmediately 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 breachof the reactor vessel by molten core debris. Specific requirements are outlined inAttachment 2 of Reference

1. Al51ý-IpzNextEra Energy Duane Arnold, LLC, 3277 DAEC Road, Palo, IA 52324 Document Control DeskNG-1 5-0169Page 2 of 2Reference 1 required submission of a phase 1 overall integrated plan pursuant toSection 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 thesix-month status report pursuant to Section IV, Condition D, of Reference 1, thatdelineates progress made in implementing the requirements of Reference

1. Theenclosed report provides an update of milestone accomplishments since the last statusreport, including any changes to the compliance method, schedule, or need for reliefand the basis, if any.This letter contains no new regulatory commitments,

however, there are severalupdates 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. VehecVice President, Duane Arnold Energy CenterNextEra Energy Duane Arnold, LLCEnclosure cc: Director, Office of Nuclear Reactor Regulation USNRC Regional Administrator Region IIIUSNRC Project Manager, Duane Arnold Energy CenterUSNRC Resident Inspector, Duane Arnold Energy Center Enclosure to NG-15-0169 NextEra Enerqy Duane Arnold, LLC's Six-Month Status Report in Response toJune 6, 2013 Commission Order Modifying Licenses with Regard to Reliable HardenedContainment 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 toJune 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment VentsCapable 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 HardenedContainment Vent System (HCVS) that provides a reliable hardened venting capability for pre-core damage and under severe accident conditions, including those involving abreach of the reactor vessel by molten core debris, in response to Reference

2. Thisattachment provides an update of milestone accomplishments since submittal of thePhase 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 OverallIntegrated Plan (Reference 1), and are current as of June 1, 2015:" Initial Outage for Phase 1 Planning" Submit Six Month Status ReportsMilestone Schedule StatusThe following provides an update to Part 5 of the Overall Integrated Plan. It providesthe activity status of each item, and whether the expected completion date haschanged.

The dates are planning dates subject to change as design andimplementation details are developed.

There are no changes to the current target datesin the Overall Integrated Plan at this time.Target Activity Comments/

Milestone Completion Status Date ChangesDate SttsaeChne Phase I HCVS Milestone TableIssue preliminary/conceptual design report Jun 2014 CompleteSubmit Overall Integrated Implementation Jun 2014 CompletePlanInitial Outage for Phase 1 Planning Nov 2014 CompleteSubmit 6 Month Status Report Dec 2014 CompleteSubmit 6 Month Status Report Jun 2015 CompleteSubmit 6 Month Status Report Dec 2015 Not StartedDesign Complete Phase 1 Mar 2016 StartedSubmit 6 Month Status Report Jun 2016 Not StartedOperations Procedure Changes Oct 2016 Not StartedDeveloped Phase 1Page 1 of 7 NextEra Energy Duane Arnold LLC's Six Month Status Report in Response toJune 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment VentsCapable of Operation Under Severe Accident Conditions (Order Number 13-109)Target Activity Comments/

Milestone Completion Status Date ChangesDatePhase 1 HCVS Milestone TableSite Specific Maintenance and Testing Oct 2016 Not StartedProcedures Developed Phase 1Training Complete Phase 1 Oct 2016 Not StartedImplementation Outage Phase 1 End of Not StartedRF025Procedure Changes Active Phase 1 End of Not StartedRF025Walk Through Demonstration/Functional End of Not StartedTest Phase 1 RF025Submit Completion Report 60 days Not StartedafterRF025Changes to Compliance MethodThere are several updates to the design detail since the previous submittal in December2014 resulting in the following changes to the compliance method:1) The location of the Remote Operating Station (ROS) has moved from the1A4 Essential Switchgear Room in the Control Building to outside the1A3 Essential Switchgear Room in the Turbine Building.

2) The routing of the new containment hardened vent system (HCVS) piping haschanged from utilizing an existing containment penetration that supportsnormal venting to the Standby Gas Treatment System to using an existingspare penetration off the suppression pool. The vent piping will be routedinto the south reactor building stairwell, up to the refuel floor and out thereactor building roof, reference Attachment A.3) The HCVS piping will contain two new primary containment isolation valvesand a new rupture disk as shown in Attachment A.4) Attachment B is an updated listing of the HCVS instrumentation.

It should benoted that the Interim Staff Evaluation (ISE) inadvertently listed a vent pipeprocess 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 orderimplementation 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 toJune 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment VentsCapable 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 1Overall Integrated Plan or the Interim Staff Evaluation (ISE) and the status of each item.Overall Integrated Plan Phase 1 Open Item StatusConfirm secondary containment bypass leakage is Startedacceptable without an installed rupture disk or retain anappropriated diskPerform severe accident evaluation for FLEX DG and Startedreplacement gas to confirm accessibility for use for post 24hour actionsEvaluate tornado/missile effects on HCVS components Startedabove the protected area of the Reactor BuildingEvaluate the system design for H2/CO measures to be taken StartedInterim Staff Evaluation Open Item StatusMake available for NRC staff audit documentation of Startedlicensee confirmation that secondary containment leakageis acceptable without an installed rupture disk or that anappropriate rupture disk, including procedures for ruptureduring HCVS operation, is included in the HCVS design.Make available for NRC staff audit analyses demonstrating Startedthat HCVS has the capacity to vent the steam/energy equivalent of one (1) percent of licensed/rated thermalpower (unless a lower value is justified),

and that thesuppression pool and the HCVS together are able to absorband reject decay heat, such that following a reactorshutdown from full power containment pressure is restoredand then maintained below the primary containment designpressure and the primary containment pressure limit.Make available for NRC staff audit evaluations of tornado Startedmissile effects on HCVS components above the protected area of the reactor building.

Make available for NRC staff audit additional detail on the Starteddesign features that minimize unintended cross flow ofvented fluids within a unit, including a one line diagramcontaining sufficient detail to confirm the description in theOIP.Page 3 of 7 NextEra Energy Duane Arnold LLC's Six Month Status Report in Response toJune 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment VentsCapable of Operation Under Severe Accident Conditions (Order Number 13-109)Interim Staff Evaluation Open Item StatusProvide a description of the final design of the HCVS to Startedaddress hydrogen detonation and deflagration.

Provide a description.

of the strategies for hydrogen control Startedthat minimizes the potential for hydrogen gas migration andingress into the reactor building or other buildings.

Make available for NRC staff audit documentation that Not Starteddemonstrates adequate communication between the remoteHCVS operation locations and HCVS decision makersduring ELAP and severe accident conditions.

Make available for NRC staff audit an evaluation of Startedtemperature and radiological conditions to ensure thatoperating personnel can safely access and operate controlsand support equipment.

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

Make available for NRC staff audit the final sizing evaluation Startedfor 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 themaximum expected differential pressure during BDBEE and.severe accident wetwell venting.Make available for NRC staff audit descriptions of all Startedinstrumentation and controls (existing and planned)necessary to implement this order including qualification methods.Make available for NRC staff audit the descriptions of local Startedconditions (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 HCVSventing including confirmation that the components arecapable of performing their functions during ELAP andsevere 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 OrderEA-13-109.

Page 4 of 7 NextEra Energy Duane Arnold LLC's Six Month Status Report in Response toJune 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment VentsCapable 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 willutilize 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 theIEEE 344-2004 standard or a substantially similar industrial standardand therefore will not be deviating from NEI 13-02 or JLD-ISG-2013-02.

Interim Staff Evaluation ImpactsThere 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 nolonger use existinq containment isolation valves. The revised vent pipe routing willinstead 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 twonew containment isolation valves will open under the maximum expecteddifferential pressure during BDBEE and severe accident wetwell venting.2) It should be noted that the Interim Staff Evaluation (ISE) inadvertently listed a ventpipe 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 Plandescribed in this Enclosure.

1. NextEra Duane Arnold Energy Center, LLC's Phase 1 Overall Integrated Plan inResponse to June 6, 2013 Commission Order Modifying Licenses with Regard toReliable Hardened Containment Vents Capable of Operation Under SevereAccident Conditions (Order Number EA-13-109),"

dated June 25, 2014(ML14182A423).

2. NRC Order Number EA-13-109, "Order Modifying Licenses with Regard to ReliableHardened Containment Vents Capable of Operation Under Severe AccidentConditions" 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, datedNovember 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 toJune 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment VentsCapable of Operation Under Severe Accident Conditions (Order Number 13-109)Attachment A -Updated Layout of Proposed HCVSz Ir-- IO.Occ0]w..-w h-J° D00TTa:00MPage 6 of 7 NextEra Energy Duane Arnold LLC's Six Month Status Report in Response toJune 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment VentsCapable of Operation Under Severe Accident Conditions (Order Number 13-109)Attachment B -HCVS Indication Instruments Instrument Indication Parameter New/ Existing Location FunctionHCVS 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) needSupply to be replaced to ensure pressure isPressure adequate to operate two PCIVs(multiple cycles),

blow the rupturedisk for vent use and for purging thevent line to prevent hydrogendetonation.

Installed locally at theROS to comply with EA-13-109.

HCVS System New MCR Provides operators a positionValve Position indication for each PCIV using lightsIndication to comply with EA-13-109.

HCVS System New MCR Provides indication of order ofRadiation magnitude of radiation and indication Monitor of open vent path.HCVS UPS New ROS Provides indication of UPS voltageStatus status.Indication Compressed New MCR & ROS Provides compressed gas volumeGas Flow indication.

Totalizer Torus Air Existing MCR 1C03 Provides indication of TorusPressure

-Pressure.

P14395A/B (0-100 psig) IPage 7 of 7