GO2-16-125, Seventh Six-Month Status Update Report for the Implementation of NRC Order EA-12-049, Mitigation Strategies for Beyond Design Basis External Events

Seventh Six-Month Status Update Report for the Implementation of NRC Order EA-12-049, Mitigation Strategies for Beyond Design Basis External Events

ML16243A471
Person / Time
Site:	Columbia
Issue date:	08/30/2016
From:	Javorik A Energy Northwest
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
EA-12-049, GO2-16-125
Download: ML16243A471 (24)

Text

Alex L. Javorik Columbia Generating Station P.O. Box 968, PE04 Richland, WA 99352-0968 Ph. 509-377-8555 l F. 509-377-4150 aljavorik@energy-northwest.com EA-12-049 10 CFR 50.54(f)

August 30, 2016 GO2-16-125 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001

Subject:

COLUMBIA GENERATING STATION, DOCKET NO. 50-397 ENERGY NORTHWESTS SEVENTH SIX-MONTH STATUS UPDATE REPORT FOR THE IMPLEMENTATION OF NUCLEAR REGULATORY COMMISSION (NRC) ORDER EA-12-049 MITIGATION STRATEGIES FOR BEYOND DESIGN BASIS EXTERNAL EVENTS

References:

1. Letter dated March 12, 2012, from E. J. Leeds (NRC) and M. R. Johnson (NRC) to Energy Northwest et.al, Issuance of Order to Modify Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events

2. Letter dated March 12, 2012, from E. J. Leeds and M. R. Johnson (NRC) to Energy Northwest et.al, Request for Information Pursuant to Title 10 of the Code of Federal Regulations 50.54(f) Regarding Recommendations 2.1, 2.3, and 9.3, of the Near-Term Task Force Review of Insights from the Fukushima Dai-Ichi Accident

3. Letter GO2-12-156 dated October 30, 2012, from D. A. Swank (Energy Northwest) to the NRC, Energy Northwests Response to the March 12, 2012 Information Request - Communication Assessment

4. Letter GO2-13-034 dated February 28, 2013, from A. L. Javorik (Energy Northwest) to NRC, Energy Northwests Response to NRC Order EA-12-049 - Overall Integrated Plan for Mitigating Strategies

Dear Sir or Madam,

By Reference 1, the Nuclear Regulatory Commission (NRC) issued Order EA-12-049, which required licensees to develop, implement, and maintain guidance and strategies for mitigation of beyond-design-basis external events. Reference 4 transmitted the Mitigation Strategies Overall Integrated Plan (OIP) for Columbia prepared in response to Reference 1.

G02-16-125 Page 2 of 2 Reference 1 also required submittal of status reports at six month intervals following initial submittal of the OIP. The enclosure to this letter provides Energy Northwest's seventh six-month status report regarding the implementation of the mitigation strategies.

By Reference 2, the NRC requested that licensees assess the communications systems and equipment that would be used during an emergency. Energy Northwest submitted the communications assessment for Columbia in Reference 3 and committed to provide the NRC with the status of the implementing actions identified in the assessment as part of the six-month status reports prepared in response to Reference 1. Letter G02 124, dated August 25, 2015 reported all open items from the Communications Assessment as complete. Therefore, Energy Northwest will not provide continued updates on the subject.

There are no new or revised regulatory commitments contained in this submittal. If you have any questions or require additional information, please contact Ms. L. L. Williams at (509) 377-8148.

I declare under penalty of perjury that the foregoing is true and correct.

Executedonthis~ayof A"7'*1f ,2016.

Respectfully

~/ .

A. L. Javorik Vice President, Engineering

Enclosures:

As stated cc: NRC Region IV Administrator NRC NRA Project Manager NRC Senior Resident lnspector/988C CA Sonoda - BPA/1399

ENCLOSURE TO GO2-16-125 COLUMBIA GENERATING STATION, DOCKET NO. 50-397 ENERGY NORTHWESTS SEVENTH SIX-MONTH STATUS UPDATE REPORT FOR THE IMPLEMENTATION OF NUCLEAR REGULATORY COMMISSION (NRC)

ORDER EA-12-049 MITIGATION STRATEGIES FOR BEYOND DESIGN BASIS EXTERNAL EVENTS

GO2-16-125 Enclosure Page 1 of 21 1.0 Introduction This enclosure provides Energy Northwests seventh six-month status report of the Mitigation Strategies Overall Integrated Plan (OIP). This six-month status report provides an update of milestone accomplishments and open items since the previous submittal.

2.0 Milestone Accomplishments All the Milestones required to support restart from Refueling Outage 22 (implementation outage) were reported as complete in letter GO2-16-037 dated February 24, 2016, with the exception of plant changes directly associated with the reliable hardened containment vent required by Reference 5.

3.0 Milestone Schedule Status The following table is provided as an update to the milestone schedule documented in the initial submittal of the Mitigation Strategies Overall Integrated Plan.

Target Target Milestones Commence Completion Activity Status Date Date Correspondence & Reports:

Submit 60 Day Initial Mitigation Completed Oct. 2012 Oct. 2012 Strategies Status Report GO2-12-149 Submit Mitigation Strategies Overall Completed Feb. 2013 Feb. 2013 Integrated Plan GO2-13-034 First Status Update Report for the Completed Mitigation Strategies Overall Aug. 2013 Aug. 2013 GO2-13-123 Integrated Plan Second Status Update Report for the Completed Mitigation Strategies Overall Feb. 2014 Feb. 2014 GO2-14-031 Integrated Plan Third Status Update Report for the Completed Mitigation Strategies Overall Aug. 2014 Aug. 2014 GO2-14-131 Integrated Plan Fourth Status Update Report for the Completed Mitigation Strategies Overall Feb. 2015 Feb. 2015 GO2-15-034 Integrated Plan Fifth Status Update Report for the Completed Mitigation Strategies Overall Aug. 2015 Aug. 2015 GO2-15-124 Integrated Plan Sixth Status Update Report for the Completed Mitigation Strategies Overall Feb. 2016 Feb. 2016 GO2-16-037 Integrated Plan Seventh Status Update Report for Completed the Mitigation Strategies Overall Aug. 2016 Aug. 2016 This Letter Integrated Plan

GO2-16-125 Enclosure Page 2 of 21 Target Target Milestones Commence Completion Activity Status Date Date Eighth Status Update Report for the Mitigation Strategies Overall Feb. 2017 Feb. 2017 Not Started Integrated Plan Issuance of Energy Northwest letter of compliance with NRC Order EA- Jun. 2017 Aug. 2017 Not Started 12-049,Section IV.C.3 Evaluations for Mitigation Strategies Phase 1, 2 & 3 Completed Perform Engineering Evaluations Jun. 2013 Apr. 2015 GO2-15-124 Engineering & Modifications for Mitigation Strategies Phase 1, 2 & 3 Develop Engineering Design for Completed Jun. 2013 Apr. 2015 Modifications GO2-15-124 Completed Plant Modification Installation Apr. 2014 Jun. 2015 GO2-15-124 Diverse and Flexible Coping Strategies (FLEX) Support Guidelines (FSG) Program &

Procedures:

Perform FLEX procedure tabletop Completed Dec. 2014 Apr. 2015 exercise GO2-15-124 Completed Develop FSGs Jul. 2013 Apr. 2015 GO2-15-124 Develop testing, calibration, maintenance and surveillance Completed Jan. 2014 Apr. 2015 procedures for portable FLEX GO2-15-124 equipment FLEX Program Procedural Changes Completed Jun. 2015 Jun. 2015 are placed in effect GO2-15-124 Procurement & Storage Plan:

Complete modification and Completed Oct. 2013 Jun. 2014 installation of FLEX buildings GO2-15-034 Procure and store necessary FLEX Completed Jun. 2013 Apr. 2015 portable equipment GO2-15-124 Completed Test portable FLEX equipment Mar. 2014 Apr. 2015 GO2-15-124 Establish programmatic controls for Completed Jan. 2014 Apr. 2015 portable FLEX equipment GO2-15-124 Mitigation Strategies Staffing Analysis:

GO2-16-125 Enclosure Page 3 of 21 Target Target Milestones Commence Completion Activity Status Date Date Perform Mitigation Strategies Staffing Completed Aug. 2014 Dec. 2014 Analysis GO2-15-124 Operations & Training:

Development of Mitigation Strategies Completed Jan. 2015 Mar. 2015 Program training modules GO2-15-124 Mitigation Strategies Program Completed Mar. 2015 Jun. 2015 training of station personnel GO2-15-124 Operational/Functional Testing of Mitigation Strategies Program Completed Mar. 2015 Jun. 2015 Structures, Systems, Components GO2-15-124 (SSC)

Final Mitigation Strategies Program Completed Jun. 2015 Jun. 2015 turned over to Operations GO2-15-124 4.0 Changes to the Compliance Method No additional changes to the method of compliance are being identified.

5.0 Need for Relief/Relaxation and Basis for the Relief/Relaxation The mitigation strategies contained in the initial OIP (Reference 2) were dependent, in part, on the hardened containment wetwell venting capabilities that were to be implemented by NRC Order EA-12-050 (Reference 4) coincident with the implementation of the FLEX strategies. NRC Order EA-13-109 (Reference 5) rescinded Reference 4 requirements and imposed additional requirements for severe accident capable hardened containment venting capabilities. Consistent with EA-13-109 Phase 1 requirements, Energy Northwest plans to complete installation of the hardened containment wetwell vent during the spring 2017 refueling outage. However, full compliance with EA-12-049 was required prior to restarting from the spring 2015 Columbia refueling outage. As requested in Reference 7 and approved in Reference 8, full compliance with NRC Order EA-12-049 was relaxed until the completion of the spring 2017 refueling outage to allow sufficient time to implement a severe accident capable hardened containment wetwell vent.

No additional relief or relaxation has been identified. Additionally, the need for an amendment request to support pending modifications has not been identified.

6.0 Open Items from Overall Integrated Plan The following table provides a summary and status of the open items documented in the initial submittal of the Mitigation Strategies OIP (Reference 2), Revision 1 of the Mitigation Strategies OIP contained in the second six-month status update (Reference 9), and responses to NRC Audit Questions regarding the mitigation strategies. This section shows that the activities required to meet NRC Order EA-12-049 are complete.

The flooding hazard analysis and hardened containment vent items remain open.

GO2-16-125 Enclosure Page 4 of 21 Mitigation Strategies Overall Integrated Plan Open Items List Status Hazards:

OI-FLEX FLEX equipment will be stored in structures capable of withstanding the hazards applicable to Columbia described above. These structures are generally referred to as FLEX Buildings. Two FLEX buildings or structures will be utilized to provide diverse storage locations that can maintain an Completed appropriate environment for the stored equipment and provide GO2-15-034 generator backed power as necessary. The construction of the storage facilities is in progress. The list of equipment to be stored therein is being developed, including any vehicles required to move the equipment. The storage of equipment within buildings has been specified to limit seismic interactions.

OI-FLEX The potential failure of a circulating water (CW) pipe, coincident with the extended loss of alternating current (ac)

Completed power (ELAP), will be considered to ensure that the FLEX GO2-14-031 storage areas are located such that deployment of at least one set of portable equipment can be accomplished.

OI-FLEX Equipment stored outside will be evaluated for Completed seismic interactions, cold weather operation and ashfall. GO2-15-034 OI-FLEX The locations and design of equipment connection points are being developed and will ensure at least one connection point for the FLEX equipment requires access only Completed through seismically robust structures including both the GO2-15-034 connection point and any areas that plant personnel will have to access.

OI-FLEX The procedural interface in NEI 12-06 Section Completed 5.3.3.1 (alternate instrument readouts) will be developed once the GO2-15-034 critical monitoring parameters are identified.

OI-FLEX Evaluation of FLEX equipment will be completed to ensure proper functioning under the design basis temperatures Completed and ashfall conditions. This includes manual actions to transport GO2-15-124 and set up the equipment.

OI-FLEX Actions will be developed to ensure the continued availability of the water inventory sources from the SW ponds in cold weather. In addition, actions will be developed to thaw any Completed frozen service water piping that will be required in Phase 3. The GO2-15-034 plan to remove ice and snow from equipment deployment routes is under evaluation and actions will be developed as needed.

Assumptions:

(Some Assumptions may be impacted by the completion of activities developed for Hardened Vents)

OI-FLEX The sequence of events developed to address the ELAP and loss of the ultimate heatsink (LUHS) will take into Completed account sources of expected reactor coolant inventory loss. (NRC GO2-14-131 Audit Question 15)

GO2-16-125 Enclosure Page 5 of 21 Mitigation Strategies Overall Integrated Plan Open Items List Status OI-FLEX Modular Accident Analysis Program (MAAP) analysis will be performed. The resulting time line will establish Completed the necessary actions that will be taken to protect both the core GO2-14-131 and containment.

OI-FLEX GOTHIC calculations will evaluate the effects of a loss of heating, venting and air conditioning (HVAC) on the plant response. An evaluation of the GOTHIC results on equipment qualification will be performed. Areas of the plant requiring Completed access by personnel (including activities identified in the GO2-14-131 Appendix 1 Timeline) will be evaluated to ensure conditions will support the actions. (This OI has been changed to explicitly include activities identified in the Timeline for completeness.)

(NRC Audit Questions 23, 24, 29, 43 and 44)

OI-FLEX The design of the permanent structures, systems, and components (SSCs) used to mitigate the ELAP and LUHS Completed will be verified to be robust with respect to seismic events, floods, GO2-15-034 and high winds.

Sequence of Events:

OI-FLEX The Station Blackout (SBO)/ELAP procedure will require all load shed actions to be completed in 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />. These Completed load shed actions will be validated to ensure they can be GO2-14-131 completed within this time limit. (This OI has been changed because the existing 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> procedural limit will be maintained.)

OI-FLEX A plant modification will be performed to address Completed the potential for flooding of the RCIC room from the barometric GO2-15-034 condenser.

OI-FLEX It is estimated to take 15 minutes to complete the additional load shedding necessary for an ELAP. The 15 minute duration for shedding the additional loads will be validated. (This Deleted OI has been deleted because the ELAP load shed will be GO2-14-131 combined with the SBO load shed and performed at the start of the event.)

OI-FLEX The maximum time needed for connection of a Completed 480V FLEX generator to power the Division 1 batteries will be GO2-15-034 determined.

Programmatic:

OI-FLEX Portable FLEX equipment will be initially tested or Completed otherwise evaluated to ensure acceptable performance. GO2-15-124 OI-FLEX The maintenance and testing program for FLEX Completed equipment will be documented in the next OIP update following GO2-15-124 finalization of the program.

OI-FLEX Unavailability of equipment and applicable connections that directly perform a FLEX mitigation strategy for Completed core, containment, and spent fuel pool (SFP) will be managed in GO2-15-124 accordance with NEI 12-06.

GO2-16-125 Enclosure Page 6 of 21 Mitigation Strategies Overall Integrated Plan Open Items List Status OI-FLEX Procedures will ensure that changes to the plant design, physical plant layout, roads, buildings, and structures Completed used for the storage of portable FLEX equipment will not GO2-15-124 adversely impact the approved FLEX strategy.

OI-FLEX Changes to FLEX strategies will be assessed using Completed the change process provided in NEI 12-06 Section 11.8. GO2-15-124 OI-FLEX Periodic training will be provided to site emergency response leaders on Beyond Design Basis emergency response Completed strategies and implementing guidelines. (This OI has been GO2-15-034 changed to reflect the requirement for periodic training stated in NEI 12-06 paragraph 11.6.2)

OI-FLEX Personnel assigned to direct execution of the mitigation strategies for Beyond Design Basis events will receive Completed the necessary training to ensure familiarity with the associated GO2-15-034 tasks.

OI-FLEX Establish staging area for the receipt of offsite Completed resources. GO2-14-131 OI-FLEX Establish site-specific Strategic Alliance for FLEX Emergency Response (SAFER) Response Plan for Columbia with the National SAFER Response Center (NSRC) to define and Completed coordinate NSRC and plant actions in response to events. (This GO2-15-034 OI has been changed to use the formal designation of the playbook.)

OI-FLEX Energy Northwest will perform an evaluation of the acceptability of the Tri-Cities Airport and the Yakima Municipal Airport as SAFER Staging Areas. (This OI has been added to Completed reflect the selection of the Tri Cities and Yakima Airports.) As a GO2-14-131 result of the evaluation, the Seattle and Portland airports were chosen as the SAFER staging areas.

Phase 1 Core Cooling:

(Some Mitigation Strategies related to Phase 1 Core Cooling may be impacted by the completion of activities developed for Hardened Vents)

OI-FLEX Procedure guidance will be developed to support Completed implementation of Phase 1 Core Cooling strategies as described GO2-15-124 in the Overall Integrated Plan.

OI-FLEX Strategies for maintaining core cooling during an ELAP and LUHS event during shutdown and refueling will be developed, including the necessary actions and equipment Completed required during Phases 1, 2, and 3. Energy Northwest will GO2-15-124 incorporate the supplemental guidance provided in the NEI position paper entitled Shutdown / Refueling Modes to enhance the shutdown risk process and procedures.

GO2-16-125 Enclosure Page 7 of 21 Mitigation Strategies Overall Integrated Plan Open Items List Status OI-FLEX System modifications and evaluations will be See Items a - e completed to support implementation of Phase 1 Core Cooling below strategies as described in the Overall Integrated Plan.

a. A reliable containment hardened vent system will be installed to vent heat from the reactor pressure vessel Completed (RPV)/containment to the atmosphere. Details of this GO2-14-107 design will be provided in the Hardened Vent Overall GO2-14-175 Integrated Plan required by NRC Order EA-13-109.

b. Analyses of reactor core isolation cooling (RCIC) operation at elevated temperatures have been undertaken by General Electric Hitachi (GEH) and Energy Northwest to identify changes to the RCIC pump or turbine necessary to Completed ensure reliable operation at elevated temperatures. GO2-15-124 Energy Northwest will evaluate potential actions including changes to procedures or maintenance practices or implementation of modifications.

c. An assessment of RCIC system piping, hangers and supports will be conducted at the elevated temperatures to Completed ensure satisfactory performance. If needed, modifications GO2-15-124 will be performed.

d. An evaluation of the feasibility of redesigning or repowering the barometric condensers level switch will be Completed performed to determine if it can remain functional during GO2-14-031 an ELAP to provide automatic control of RCIC-P-4.

e. MAAP cases using the suppression pool will be re-run using finalized design parameters of the containment hardened vent. The results will be used to define Completed additional actions. (See Open Item OI-FLEX-09). (This OI GO2-14-131 has been changed because the suppression pool will be the credited water source for initial RCIC operation.)

OI-FLEX GOTHIC analyses will be confirmed, or revised, to bound the design of the hardened containment vent after the design is finalized. (This OI has been added to assure that the subject analyses reflect the design required by EA-13-109.)

Response

Calculation ME-02-13-03 R1 results show that the hardened containment vent is able to remove the required 1% of 4079 Completed.

megawatts thermal (MWt) with a 45 psig wetwell pressure. This would include the currently proposed amendment request for a power uprate of 1.66%, submitted on June 28, 2016. This amendment request would increase the rated thermal power from the current licensed thermal power of 3486 MWt to 3544 MWt and remains bounded by this analysis which ensures that the HCVS can remove the amount of energy required by EA-13-109.

GO2-16-125 Enclosure Page 8 of 21 Mitigation Strategies Overall Integrated Plan Open Items List Status Phase 1 Containment:

(Some Mitigation Strategies Open Items not originally identified in the Overall Integrated Plan related to Phase 1 Containment have been created due to the potential impact of the schedule for activities developed for Phase 1 & 2 Hardened Vents)

OI-FLEX-27 (continued)

f. It is anticipated that temporary interim strategies will be developed for venting the containment until the completion Deleted of containment hardened vent activities. (This OI has been GO2-14-031 deleted because an interim venting strategy will not be credited for compliance with EA-12-049.)

g. It is anticipated that revisions to procedures will be developed to implement the temporary interim strategies for venting the containment until the completion of Deleted containment hardened vent activities. (This OI has been GO2-14-031 deleted because an interim venting strategy will not be credited for compliance with EA-12-049.)

Phase 2 Core Cooling:

OI-FLEX Procedure guidance will be developed to support Completed implementation of Phase 2 Core Cooling strategies as described GO2-15-124 in the Overall Integrated Plan.

OI-FLEX System modifications and evaluations will be completed to support implementation of Phase 2 Core Cooling See items a - d strategies as described in the Overall Integrated Plan. below

a. Alternate connection points will be provided to connect Completed FLEX generators to the electrical distribution system. GO2-15-124

b. An evaluation of running underground cabling from the FLEX Building(s) to the existing electrical connection Completed points outside the Diesel Generator Building will be GO2-14-131 performed.

c. DG4 or DG5 will have the capability of providing power to Division 1 and Division 2. (This OI has been changed to Completed eliminate duplication of OI-FLEX-29.b and to reflect the GO2-14-131 planned capability of the FLEX DGs)

d. Provisions will be made to allow the installation of hoses through fence(s). (This OI has been changed to reflect a Completed change in the strategy for hose routing with respect to GO2-14-131 fences.)

OI-FLEX An evaluation will be completed to ensure a diverse supply of fuel is available, maintained and diverse means are Completed provided for refueling the portable equipment. GO2-15-034

GO2-16-125 Enclosure Page 9 of 21 Mitigation Strategies Overall Integrated Plan Open Items List Status OI-FLEX Strategies for mitigating an ELAP and LUHS event during cold shutdown and refueling will be developed as Completed described in the Overall Integrated Plan. GO2-15-124 OI-FLEX An analysis will be performed to confirm that the Phase 2 configurations described in the OIP for suppression pool make-up can provide adequate flow through the spray header. Deleted (This OI has been deleted as the suppression pool make-up will GO2-14-131 not use the spray nozzles as part of the make-up flow path.)

OI-FLEX A wind and seismic evaluation in accordance with the American Society of Civil Engineers (ASCE) 7-10 Building Risk Category IV will be performed on the above ground alternate Completed gasoline tank located outside the protected area. (This OI has GO2-15-034 been added to track completion of the subject evaluation.)

Phase 3 Core Cooling:

OI-FLEX Energy Northwest will establish a site-specific Completed SAFER Response Plan for Columbia with the NSRC to define GO2-15-034 and coordinate NSRC and plant actions in response to events.

OI-FLEX Modifications and evaluations will be completed to See Items a - b support implementation of Phase 3 Core Cooling strategies as below described in the Overall Integrated Plan.

a. Two separate connection points will be installed to provide Completed critical bus power from a 4160-V ac FLEX generator (From GO2-15-034 the NSRC).

b. A strategy for connecting the large FLEX pump to the service water (SW) system will be developed. SW system Completed piping will be modified if needed to provide connection GO2-15-034 points.

OI-FLEX The spray pond temperature rise while operating in the shutdown cooling mode without sprays will be determined. Completed (This OI has been added to determine if cooling tower make-up GO2-14-131 (TMU) pump operation will be needed.)

Phase 1 SFP Cooling:

Procedure guidance will be developed to support implementation of Phase 1 SFP Cooling strategies. (As discussed in the Overall Integrated Plan, the SFP does not require any action in Phase 1.

The inventory of water in the pool is generally maintained greater Deleted than or equal to 22 feet above the top of irradiated fuel GO2-14-031 assemblies stored in the fuel pool. The heat up of the pool water will remove heat from the stored fuel during Phase 1, therefore this open item can be Deleted)

GO2-16-125 Enclosure Page 10 of 21 Mitigation Strategies Overall Integrated Plan Open Items List Status OI-FLEX Modifications will be completed to support implementation of Phase 1 SFP Cooling strategies.

Phase 1 relies on the use of installed plant equipment. As stated in GO2-14-031, the SFP does not require any action in Phase 1.

The inventory of water in the SFP is generally maintained greater Completed than or equal to 22 feet above the top of irradiated fuel GO2-15-124 assemblies stored in the fuel pool. The heat up of the pool water will remove heat from the stored fuel during Phase 1. There are no modifications required for SFP cooling strategies. The SFPLI modification required by EA-12-051 has been completed as reported in letter GO2-15-120.

Phase 2 SFP Cooling:

OI-FLEX Procedure guidance will be developed to support implementation of Phase 2 SFP Cooling strategies as described Completed in the OIP. (This OI has been added to track the procedure GO2-15-124 development needed to support Phase 2 SFP Cooling.)

OI-FLEX The time that make-up to the SFP must be initiated after an ELAP will be determined for a full core off-load. Completed GO2-14-131 Phase 3 SFP Cooling:

OI-FLEX Procedure guidance will be developed to support Completed implementation of Phase 3 SFP Cooling strategies. GO2-15-124 OI-FLEX Evaluations will be completed to support implementation of Phase 3 SFP Cooling strategies.

a. An evaluation of the ability of the 4160-V ac FLEX generator (from the NSRC) to repower a Fuel Pool Cooling (FPC) pump Completed will be completed. An evaluation of the ability of the large- GO2-14-131 capacity FLEX pump (from the NSRC) to provide cooling to the FPC heat exchanger will be completed.

Phase 1 Safety Support Functions:

OI-FLEX Procedure guidance will be developed to support Completed implementation of Phase 1 Safety Function Support strategies as GO2-15-034 described in the Mitigation Strategies Overall Integrated Plan.

OI-FLEX System modifications will be completed to support implementation of Phase 1 Safety Function Support strategies as described in the Mitigation Strategies Overall Integrated Plan.

a. GOTHIC modeling is ongoing in support of the ELAP that will Completed identify heat loads in the key locations between the buildings.

GO2-15-034 This analysis will then define additional actions that may be required using portable equipment, or any modifications to support operation of installed equipment during Phase 1.

No system modifications were required.

GO2-16-125 Enclosure Page 11 of 21 Mitigation Strategies Overall Integrated Plan Open Items List Status Phase 3 Safety Support Functions:

OI-FLEX An evaluation of the conditions of the residual heat removal (RHR) pump rooms under an ELAP event will be Completed completed to determine if additional actions are needed to GO2-14-131 remove heat from the rooms prior to and during operation of the pump.

Appendix 1 - Sequence of Events Timeline:

OI-FLEX Modification to the sequence of events timeline will Completed be provided in future status update reports as analyses, GO2-15-034 strategies and evaluations are completed.

Appendix 2 - Milestone Schedule:

None - Revisions to the milestone schedule are identified in N/A Section 2 of this and subsequent future status update reports.

Appendix 3 - Conceptual Sketches:

OI-FLEX Updated sketches will be provided in future status Completed reports if needed to reflect changes. GO2-14-131 NRC Audit Question Responses:

OI-FLEX NEI 12-06, Section 5.3.3 Consideration 2:

Consideration should be given to the impacts from large internal flooding sources that are not seismically robust and do not Completed require ac power (e.g., gravity drainage from lake or cooling GO2-14-131 basins for non-safety-related cooling water systems, will be addressed in future six-month updates. (Response to NRC Audit Question 02)

OI-FLEX The flooding hazards analysis will provide information about site water level associated with a probable maximum precipitation (PMP) event and a local intense precipitation (LIP) event. These water levels will be compared to elevations for the FLEX buildings as well as the deployment routes for the equipment. A LiDAR survey of the site was performed and a topographic plan of the site has been generated Started to assist in this evaluation. The flooding analysis is currently in progress. The results will be used to provide a response to this question in a future OIP update. (Response to NRC Audit Question 03) (This OI has been changed because the flooding analysis remains in progress and the OI was not closed in the February 2014 update.)

OI-FLEX A future update to the OIP will address the applicability to Columbia of each of the nine considerations in NEI 12-06 Section 6.2.3.2, Deployment of FLEX Equipment.

Started (Response to NRC Audit Question 04) (This OI has been changed because the flooding analysis remains in progress and the OI will be closed in a future update.)

GO2-16-125 Enclosure Page 12 of 21 Mitigation Strategies Overall Integrated Plan Open Items List Status OI-FLEX The flooding analysis will be used to determine if any of the external flooding procedures should be changed. Not Started (Response to NRC Audit Question 04)

OI-FLEX The NRC has endorsed generic resolutions of concerns regarding use of the MAAP code in mitigation strategies. Energy Northwest will assess the applicability of the generic resolutions to Columbia. (Response to NRC Audit Question 09) Columbia has completed an assessment of the generic resolution of the issues related to use of MAAP4 for our ELAP work. The assessment focused on the limitations imposed by the NRC on their acceptance of the use of MAAP4 for timeline Completed purposes as stated in the NRC letter dated October 3, 2013, from GO2-14-131 Jack R. Davis (NRC) to Joseph E. Pollock (NEI). Columbia has used MAAP4 for the determination of wetwell vent timing, fuel pool cooling/make-up timing, and for RCIC operability assessments based on calculated suppression pool temperature. All the limitations in the NRC letter have been addressed in the assessment which is available for review upon request.

OI-FLEX A review of the current fire protection ring header shows that it was designed to Seismic Category II standards outside Seismic Category I structures. Except for minor portions, Completed it is buried in engineered fill and is largely protected from the GO2-14-031 effects of high winds and missiles. While use of the fire protection ring header is an operational convenience, its availability is not credited (Response to NRC Audit Question 13).

OI-FLEX The NRC has endorsed a generic resolution of concerns regarding use of the MAAP code in mitigation Completed strategies. Energy Northwest will assess the applicability of the GO2-14-131 generic resolution to Columbia. (Response to NRC Audit Question 14) See the response in OI-FLEX-46 above.

OI-FLEX GOTHIC analyses of the Vital Island will evaluate hydrogen generation in the battery rooms. The results of those Completed analyses will determine the need, if any, for measures needed to GO2-14-031 control hydrogen concentrations in the battery rooms. (Response to NRC Audit Question 28)

OI-FLEX At the point when ELAP mitigation activities require tie-in of FLEX generators, in addition to existing electrical interlocks, procedural controls, such as inhibiting generator start circuits and breaker rack-outs, will be employed to prevent Completed simultaneous connection of both the FLEX generators and Class GO2-15-124 1E generators to the same AC distribution system or component.

FLEX strategies, including the transition from installed sources to portable sources (and vice versa), will be addressed in the FLEX procedures. (Response to NRC Audit Question 50)

GO2-16-125 Enclosure Page 13 of 21 Mitigation Strategies Overall Integrated Plan Open Items List Status OI-FLEX Energy Northwest will address the considerations Completed in NEI 12-06, Section 12.2. (Response to NRC Audit Question GO2-14-131 34)

OI-FLEX Plant specific ELAP analysis results will be provided in the format and detail equivalent to NEDC-33771P. Completed Energy Northwest will provide the information in a subsequent GO2-15-034 six-month update. (Response to NRC Audit Question 36)

OI-FLEX The issue of maintenance and testing of portable FLEX equipment is being addressed and coordinated on an industry-wide basis. Energy Northwest will continue to monitor and participate in these industry activities so that it can develop a maintenance and testing program that meets acceptable standards (including NEI 12-06), and is consistent with those used generically throughout the industry. Energy Northwest will also utilize existing station procedures coupled with vendor technical information for establishing preventive maintenance Completed activities and schedules. The Columbia maintenance and testing GO2-15-124 program for FLEX equipment will be documented in the next OIP update following finalization of the program. (Response to NRC Audit Question 40)

The maintenance and testing program for portable FLEX equipment has been added to the FLEX Program Document.

NRC SE Tracker items 33-B and 7-E have been posted to the E-portal. No additional OIP update will be made.

OI-FLEX Finalize the sizing calculation for the FLEX generators for phase 2 and 3. Completion of this activity is necessary to provide a comprehensive response to this question Completed (i.e. NRC Audit Question 42 requesting a summary of the sizing GO2-14-131 calculation for the FLEX generators to show that they can supply the loads assumed in phases 2 and 3). (Response to NRC Audit Question 42).

OI-FLEX Finalization of the capacity and power requirements calculation for Phase 3 is not complete.

Completion of this activity is necessary to provide a comprehensive response to this question (i.e. NRC Audit Completed Question 45 requesting a description of the electrical power GO2-14-131 requirements for Phase 3 of the mitigating strategies integrated plan and the capacity of the power sources). (Response to NRC Audit Question 45) See OI-FLEX-54 Summary Above.

GO2-16-125 Enclosure Page 14 of 21 Mitigation Strategies Overall Integrated Plan Open Items List Status OI-FLEX Energy Northwest will validate the ability to successfully accomplish each bypass under the expected conditions of a prolonged station blackout as part of the Completed procedure approval process. Based on incorporation of the GEH GO2-15-034 recommended trip bypasses, the potential for equipment protection features to interfere with operation of RCIC will be minimized. (Response to NRC Audit Question 56)

OI-FLEX Energy Northwest will perform an evaluation to compare (1) the quantity of water required to dissipate, for 72 Completed hours, the decay heat of the reactor core and spent fuel pool GO2-14-031 during Phases 1 and 2, (2) the volume of water normally in the spray ponds. (Response to NRC Audit Question 05)

OI-FLEX Energy Northwest's periodic OIP updates will identify any planned modifications that it determines may require Completed NRC approval per 10 CFR 50.90. (Response to NRC Audit GO2-15-034 Question 22) No planned modifications require NRC approval.

OI-FLEX The Spent Fuel Pool section of the OIP will be Completed updated to reflect actions taken in the event of full core off-load to GO2-14-131 the pool. (Response to NRC Audit Question 24)

OI-FLEX This issue (early venting) was identified as a generic concern or question which the nuclear industry will resolve generically through the Nuclear Energy Institute (NEI) Completed and the applicable industry groups (e.g., Boiling Water Reactor GO2-14-031 Owners Group (BWROG), Electric Power Research Institute (EPRI), etc.). (Response to NRC Audit Question 25)

OI-FLEX An updated schedule for the Energy Northwest Completed identified open items will be included in the six-month updates of GO2-14-131 the Columbia OIP. (Response to NRC Audit Question 46)

OI-FLEX Calculations NE-02-12-02, ME-02-12-06, ME Completed 12-07, 2.05.0,1 and CMR-11179 have been uploaded to the GO2-14-131 Columbia Fukushima portal. (Response to NRC Audit Question GO2-15-034 47)

OI-FLEX The timeline in Appendix 1 of the February 28, 2013 Overall Integrated Plan (OIP) for Order EA-12-049 will be revised as necessary to reflect use of the existing ductwork rather Deleted than the hardened containment vent. (Response to NRC Audit GO2-14-031 Question 58) (This OI has been deleted because use of ductwork for containment venting will not be credited for compliance with EA-12-049)

OI-FLEX Energy Northwest will address the conformance to Completed the guidance of NEI 12-06, Section 3.2.2, Guideline (12).

GO2-14-131 (Response to NRC Audit Question 61)

GO2-16-125 Enclosure Page 15 of 21 Mitigation Strategies Overall Integrated Plan Open Items List Status OI-FLEX The NEI position paper includes instructions for licensees to incorporate the following template wording into their OIPs:

Completed (Name of licensee) will incorporate the supplemental guidance GO2-14-031 provided in the NEI position paper entitled Shutdown / Refueling Modes to enhance the shutdown risk process and procedures.

(Response to NRC Audit Question 62A)

OI-FLEX The NEI white paper includes instructions for licensees to incorporate the following template wording into their OIPs:

[Insert Licensee] confirms that the FLEX strategy station battery run-time was calculated in accordance with the Institute of Electrical and Electronics Engineers (IEEE)-485 methodology using manufacturer discharge test data applicable to the licensees FLEX strategy as outlined in the NEI white paper on Extended Battery Duty Cycles. The detailed licensee calculations, supporting vendor discharge test data, FLEX Completed strategy battery load profile, and other inputs/initial conditions GO2-15-034 required by IEEE-485 will be available on the licensees web portal for documents and calculations. The time margin between the calculated station battery run-time for the FLEX strategy and the expected deployment time for FLEX equipment to supply the dc loads is [8] hours.

Energy Northwest will incorporate this template wording into a future OIP update. (Response to NRC Audit Question 62B)(This OI has been changed because the validation of actual time deploying the 480-V ac FLEX generators per OI-FLEX-15 has not been completed.)

OI-FLEX The load shedding procedure is in the process of being developed. The procedure will also direct operators to depressurize the main generator manually if the main generator Completed is pressurized with hydrogen before shedding the air side seal oil GO2-14-131 backup pump. These actions are expected to preclude a potential fire and/or explosion from the hydrogen. (Response to NRC Audit Question 50) 7.0 Interim Staff Evaluation Reference 6 transmitted an NRC Interim Staff Evaluation and Audit Report (ISE) which documented the results of a review of the Columbia OIP (Reference 2), six-month update (Reference 3), and information obtained through the NRCs mitigation strategies audit process. The ISE documented the staffs conclusion that Energy Northwest has provided sufficient information to determine that there is reasonable assurance that the OIP, when properly implemented, will meet the requirements of Order EA-12-049 at Columbia. That conclusion was based on the assumption that Energy Northwest would implement the OIP as described, including the satisfactory resolution of the Open and

GO2-16-125 Enclosure Page 16 of 21 Confirmatory Items tabulated in the ISE. In February 2015 the NRC conducted an on-site audit of the implementation of the requirements of Reference 1 (Mitigation) and NRC Order EA-12-051 on Reliable Spent Fuel Pool Instrumentation. The audit reviewed the Open and Confirmatory items previously identified in this section. The status of the remaining Open, Confirmatory, and New items are now tracked in Section 8.0 below.

8.0 Open Items from the Audit Regarding Implementation Reference 12 transmitted the audit report of the February 2015 audit regarding the implementation of the mitigation strategies and reliable spent fuel pool instrumentation Orders. The following table was reproduced from Attachment 3 of the audit report and includes the status of Columbia's response to the open items listed. Where indicated, the requested information has been posted on the Columbia e-portal as outlined in the Columbia Audit Plan dated January 16, 2015.

OPEN ITEMS FROM THE FEBRUARY 2015 MITIGATION/SFPI AUDIT Audit Item Description Licensee Input Needed Item Confirm that FLEX equipment can be Licensee Open Items 43 through 45 adequately protected and deployed in such remain open as EN is performing a ISE OI an event and whether flooding procedures local intense precipitation analysis.

3.1.2.1.A account for the use of FLEX equipment. Response:

Pending completion of the flooding hazards analysis.

The licensee has not completed calculations Licensee to evaluate head loss to the supporting the design of the FLEX spent fuel pool while simultaneously ISE CI equipment. Confirm that portable FLEX filling SFP and RPV level.

3.2.1.4.A equipment is adequate to perform its Response:

credited mitigation function(s). Discussion and related calculation were posted to the E-portal on 6/2/15 Confirm that [Energy Northwest] ENs SFP Licensee to evaluate flow analysis makeup strategy for Columbia provides for for filling SFP through RHR B loop.

ISE CI SFP makeup without accessing the refueling Response:

3.2.2.D floor, as recommended in NEI 12-06, Table Flow path discussion and drawings C-3, or that an acceptable alternate were posted to the E-portal on 6/2/15 approach is developed.

The licensee's proposed strategy for The licensee needs to provide to the maintaining containment will rely on NRC staff the final configuration and installation of the hardened containment calculations for the HCVS.

vent system (HCVS) as required by Order Response:

EA-13-109. When complete, the licensee's An updated timeline for the HCVS ISE CI calculations supporting the revised response was provided in letter 3.2.3.B containment response and sequence of GO2-15-175, dated December 16, events timeline should be reviewed to 2015.

confirm that the timeline is appropriate and that containment functions will be restored and maintained following an ELAP event.

GO2-16-125 Enclosure Page 17 of 21 OPEN ITEMS FROM THE FEBRUARY 2015 MITIGATION/SFPI AUDIT Audit Item Description Licensee Input Needed Item The alternate strategy for Phase 2 core The NRC staff asked the licensee to cooling involves removal, replacement, and provide further detail of the paths reconfiguration of several flanges and piping and the locations of the connections elbows during the ELAP event. The NRC points as well as the validation of the staff requests that the licensee provide a ability to perform the actions.

AQ 41 description of the available lighting and Response:

habitability around the RHR piping where Accessibility and flange installation connections need to be made. discussion with maps and photos were posted to the E-portal on 6/9/15.

On page 18 of 60 Columbias OIP states The licensee to design the that load shedding will be performed to containment hardened vent system prolong battery life to 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br />. On page battery for a cycle of 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

22 of 60 Columbias OIP states, The 125 Response:

VDC batteries are available for 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br /> The station batteries and the HCV without recharging. The 250 VDC batteries batteries are independent of each are available for 17 hours1.967593e-4 days <br />0.00472 hours <br />2.810847e-5 weeks <br />6.4685e-6 months <br /> without other.

recharging. On page 35 of 60, with In letter GO2-15-175, dated reference to power for containment December 16, 2015, Applicable EA-hardened vent valve solenoids and 12-049 assumptions, Item 049-7 instrumentation, Columbias OIP states, states that the HCVS is independent This battery will be designed to support at from the DC power and distribution least 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of operation without any that can be credited for the duration outside power source. Provide justification determined per the EA-12-049, for the above discrepancy. Diverse and Flexible Coping Strategies (FLEX), methodology for battery usage of 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />. The power supply scheme for the HCVS shall AQ 52 be in accordance with EA-13-109 and the applicable guidance.

(Reference 10 NEI 12-06, Section 3.2.1.3 item 8)

Additionally, in the Columbia Generating Station Plant Specific HCVS Related Assumptions /

Characteristics section, Item PLT-2 states that a Class 1E, 24-V battery system dedicated to the HCVS electrical loads consisting of batteries, a battery charger, 24-V DC distribution panels, wiring, cables and raceways will be installed. The battery sizing will sustain operation for a minimum of 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> with no operator action. After 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, supplemental power will be available.

GO2-16-125 Enclosure Page 18 of 21 OPEN ITEMS FROM THE FEBRUARY 2015 MITIGATION/SFPI AUDIT Audit Item Description Licensee Input Needed Item Please address the following items Licensee to justify the ashfall event regarding the use of raw water sources for would not plug the inlets of the fuel mitigating an ELAP event: assemblies or that top down cooling

a. Discuss the quality of the water (e.g., would be used to ensure core suspended solids, dissolved salts) that will cooling.

be used for primary makeup during ELAP Response:

events, accounting for the potential for Discussion and calculation were increased suspended or dissolved material posted to the E-portal on 4/13/15 in some raw water sources during events such as flooding or severe storms.

b. Discuss whether instrumentation available during the ELAP event is capable of providing indication that inadequate core cooling exists for one or more fuel 1-E assemblies due to blockage at fuel assemblies inlets or applicable bypass leakage flowpaths.

c. Provide justification that the use of the intended raw water sources will not result in blockage of coolant flow across fuel assemblies inlets and applicable bypass leakage flowpaths to an extent that would inhibit adequate core cooling. Or, if deleterious blockage at the core inlet cannot be precluded under ELAP conditions, then please discuss alternate means for assuring the adequacy of adequate core cooling in light of available indications.

GO2-16-125 Enclosure Page 19 of 21 OPEN ITEMS FROM THE FEBRUARY 2015 MITIGATION/SFPI AUDIT Audit Item Description Licensee Input Needed Item

a. Discuss the design of the suction Licensee to analyze the suction strainers used with FLEX pumps taking strainer design and how far into the suction from raw water sources, including water it sits as well as the procedure perforation dimension(s) and approximate for ensuring that flow is not surface area. interrupted to such a length of time

b. Provide reasonable assurance that the that the fuel would remain covered.

strainers will not be clogged with debris Response:

(accounting for conditions following, Discussion and strainer vendor flooding, severe storms, earthquakes or information were posted to the E-other natural hazards), or else that the portal on 4/3/15 strainers can be cleaned of debris at a frequency that is sufficient to provide the 2-E required flow. In the response, consider the following factors:

i. The timing at which FLEX pumps would take suction on raw water relative to the onset and duration of the natural hazard.

ii. The timing at which FLEX pumps would take suction on raw water relative to the timing at which augmented staffing would be available onsite.

iii. Whether multiple suction hoses exist for each FLEX pump taking suction on raw water, such that flow interruption would not be required to clean suction strainers.

Evaluation of FLEX equipment to be Licensee to complete evaluation of completed to ensure proper functioning operating FLEX equipment under under the design-basis temperatures and ash fall conditions.

10-E ash fall conditions during both operation and Response:

storage. This includes manual actions to Evaluation was posted to the E-transport and set up the equipment as well portal on 5/20/15 as storage conditions.

Please provide an assessment of potential A strategy to mitigate EMI/RFI susceptibilities of EMI/RFI in the areas interference in the SFP area.

where the SFP instrument is located and Response:

11-E how to mitigate those susceptibilities. This response was provided in the EA-12-051 compliance letter GO2-15-120.

GO2-16-125 Enclosure Page 20 of 21 OPEN ITEMS FROM THE FEBRUARY 2015 MITIGATION/SFPI AUDIT Audit Item Description Licensee Input Needed Item The licensee is requested to provide a Provide EQ evaluation summary evaluation to confirm that the Response:

temperature and pressures within Evaluation was posted to the E-containment will not exceed the portal on 3/11/15 environmental qualification (EQ) of electrical 14-E equipment that is being relied upon as part of their FLEX strategies. The licensee needs to ensure that the EQ profile of the required electrical equipment remains bounding for the entire duration of the event.

9.0 References

1. Letter dated March 12, 2012, from E. J. Leeds (NRC to Energy Northwest et.

al, "Implementation of Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond Design Basis External Events" (EA-12-049)

2. Letter GO2-13-034 dated February 28, 2013, from A. L. Javorik (Energy Northwest) to NRC, "Energy Northwests Response to NRC Order EA 049 - Overall Integrated Plan for Mitigating Strategies"

3. Letter GO2-13-123 dated August 28, 2013, from D.A. Swank (Energy Northwest) to NRC, "Energy Northwests First Six Month Status Update Report for the Implementation of NRC Order EA-12-049 Mitigation Strategies for Beyond Design Basis External Events"

4. Letter dated March 12, 2012, from E. J. Leeds (NRC) to Energy Northwest et. al, "Issuance of Order Modifying Licenses with Regard to Reliable Hardened Containment Vents" (EA-12-050)

5. Letter dated June 6, 2013, from E. J. Leeds (NRC) to Energy Northwest et.

al, "Issuance of Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions" (EA-13-109)

6. NRC letter dated January 29, 2014, from J. S. Bowen (NRC) to M. E.

Reddemann (Energy Northwest), "Columbia Generating Station - Interim Staff Evaluation Relating to Overall Integrated Plan in Response to Order EA-12-049 (Mitigation Strategies)"

7. Letter GO2-14-026 dated February 21, 2014, from D. A. Swank (Energy Northwest) to NRC, "Request for Relaxation from NRC Order EA-12-049,

'Order Modifying Licenses With Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events'"

8. Letter dated April 15, 2014, from E. J. Leeds (NRC) to M. E. Reddemann (Energy Northwest), "Columbia Generating Station - Relaxation of Certain Schedule Requirements for Order EA-12-049 'Issuance of Order to Modify

GO2-16-125 Enclosure Page 21 of 21 Licenses with Regard to Requirements for Mitigation Strategies for Beyond Design Basis External Events'"

9. Letter GO2-14-031, dated February 27, 2014, from D. A. Swank (Energy Northwest) to NRC, "Energy Northwest's Second Six Month Status Update Report for the Implementation of NRC Order EA-12-049 Mitigation Strategies for Beyond Design Basis External Events"

10. Letter GO2-14-131 dated August 28, 2014, from D. A. Swank (Energy Northwest) to the NRC, "Energy Northwest's Third Six-Month Status Update Report for the Implementation of NRC Order EA-12-049 Mitigation Strategies for Beyond Design Basis External Events"

11. Letter GO2-15-034 dated March 2, 2015, from D. A. Swank (Energy Northwest) to the NRC, "Energy Northwest's Fourth Six-Month Status Update Report for the Implementation of NRC Order EA-12-049 Mitigation Strategies for Beyond Design Basis External Events"

12. Letter dated June 16, 2015, from S. Monarque (NRC) to M. E. Reddemann (Energy Northwest), "Columbia Generating Station - Report for the Audit Regarding Implementation of Mitigation Strategies and Reliable Spent Fuel Pool Instrumentation Related to Orders EA-12-049 and EA-12-051"

13. Letter GO2-14-107 dated June 30, 2014, from D. A. Swank (Energy Northwest) to the NRC, "Energy Northwest's Phase 1 Response to NRC Order EA-13-109 - Overall Integrated Plan for Reliable Hardened Containment Vents Under Severe Accident Conditions"

14. Letter GO2-14-175 dated December 17, 2014, from D. A. Swank (Energy Northwest) to the NRC, "Energy Northwest's First Six-Month Status Update Report for the Implementation of NRC Order EA-13-109 - Overall Integrated Plan for Reliable Hardened Containment Vents Under Severe Accident Conditions"

15. Letter GO2-15-124 dated August 25, 2015, from D. A. Swank (Energy Northwest) to the NRC, "Energy Northwest's Fifth Six-Month Status Update Report for the Implementation of NRC Order EA-12-049 Mitigation Strategies for Beyond Design Basis External Events"

16. Letter GO2-15-175 dated December 16, 2015, from A. L. Javorik (Energy Northwest) to the NRC, "Energy Northwests Response to NRC Order Ea 109 -Overall Integrated Plan for Reliable Hardened Containment Vents Under Severe Accident Conditions Phases 1 and 2, Revision 1"