Text

Sixth Six-Month Status Report in Response to March 12, 2012 Commission Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events (Order Number EA-12-049)
	ML16057A008
Person / Time
Site:	Oyster Creek
Issue date:	02/26/2016
From:	David Helker; Exelon Generation Co
To:	; Document Control Desk, Office of Nuclear Reactor Regulation
References
	EA-12-049, RA-16-010, RS-16-025
	Download: ML16057A008 (14)
	v • d • e

Exelon Generation ~)

Order No. EA-12-049 RS-16-025 RA-16-010 February 26, 2016 U.S. Nuclear Regulatory Commission ATIN: Document Control Desk Washington, DC 20555-0001 Oyster Creek Nuclear Generating Station Renewed Facility Operating License No. DPR-16 NRC Docket No. 50-219

Subject:

Sixth Six-Month Status Report in Response to March 12, 2012 Commission Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events (Order Number EA-12-049)

References:

1. NRC Order Number EA-12-049, "Issuance of Order to Modify Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events," dated March 12, 2012

2. NRC Interim Staff Guidance JLD-ISG-2012-01, "Compliance with Order EA-12-049, Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events," Revision 0, dated August 29, 2012

3. NEI 12-06, "Diverse and Flexible Coping Strategies (FLEX) Implementation Guide,"

Revision 0, dated August 2012

4. Exelon Generation Company, LLC's Initial Status Report in Response to March 12, 2012 Commission Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events (Order Number EA-12-049), dated October 25, 2012

5. Exelon Generation Company, LLC Overall Integrated Plan in Response to March 12, 2012 Commission Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events (Order Number EA-12-049), dated February 28, 2013 (RS-13-023)

6. Exelon Generation Company, LLC First Six-Month Status Report in Response to March 12, 2012 Commission Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events (Order Number EA 049), dated August 28, 2013 (RS-13-125)

7. Exelon Generation Company, LLC Second Six-Month Status Report in Response to March 12, 2012 Commission Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events (Order Number EA 049), dated February 28, 2014 (RS-14-013)

8. Exelon Generation Company, LLC Third Six-Month Status Report in Response to March 12, 2012 Commission Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events (Order Number EA 049), dated August 28, 2014 (RS-14-211)

U.S. Nuclear Regulatory Commission Integrated Plan Report to EA-12-049 February 26, 2016 Page 2

9. Exelon Generation Company, LLC Fourth Six-Month Status Report in Response to March 12, 2012 Commission Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events (Order Number EA 049), dated February 27, 2015 (RS-15-022)

10. Exelon Generation Company, LLC Fifth Six-Month Status Report in Response to March 12, 2012 Commission Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events (Order Number EA 049), dated August 28, 2015 (RS-15-213)

11. NRG letter to Exelon Generation Company, LLC, Oyster Creek Nuclear Generating Station - Interim Staff Evaluation Relating to Overall Integrated Plan in Response to Order EA-12-049 (Mitigation Strategies) (TAC No. MF0824), dated February 19, 2014 On March 12, 2012, the Nuclear Regulatory Commission ("NRC" or "Commission") issued an order (Reference 1) to Exelon Generation Company, LLC (EGG). Reference 1 was immediately effective and directs EGC to develop, implement, and maintain guidance and strategies to maintain or restore core cooling, containment, and spent fuel pool cooling capabilities in the event of a beyond-design-basis external event. Specific requirements are outlined in of Reference 1.

Reference 1 required submission of an initial status report 60 days following issuance of the final interim staff guidance (Reference 2) and an overall integrated plan pursuant to Section IV, Condition C. Reference 2 endorses industry guidance document NEI 12-06, Revision 0 (Reference 3) with clarifications and exceptions identified in Reference 2. Reference 4 provided the EGG initial status report regarding mitigation strategies. Reference 5 provided the Oyster Creek Nuclear Generating Station Overall Integrated Plan.

Reference 1 requires submission of a status report at six-month intervals following submittal of the Overall Integrated Plan. Reference 3 provides direction regarding the content of the status reports. References 6, 7, 8, 9, and 10 provided the first, second, third, fourth, and fifth six-month status reports, respectively, pursuant to Section IV, Condition C.2, of Reference 1 for Oyster Creek Nuclear Generating Station. The purpose of this letter is to provide the sixth six-month status report pursuant to Section IV, Condition C.2, 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. The enclosed report also addresses the NRC Interim Staff Evaluation Open and Confirmatory Items contained in Reference 11 .

This letter contains no new regulatory commitments. If you have any questions regarding this report, please contact David P. Helker at 610-765-5525.

U.S. Nuclear Regulatory Commission Integrated Plan Report to EA-12-049 February 26, 2016 Page 3 I declare under penalty of perjury that the foregoing is true and correct. Executed on the 26th day of February 2016.

Respectfully submitted, David P. Helker Manager - Licensing & Regulatory Affairs Exelon Generation Company, LLC

Enclosure:

1. Oyster Creek Nuclear Generating Station Sixth Six-Month Status Report for the Implementation of Order EA-12-049, Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events cc: NRC Regional Administrator - Region I NRC Senior Resident Inspector - Oyster Creek Nuclear Generating Station NRC Project Manager, NRA - Oyster Creek Nuclear Generating Station Mr. John D. Hughey, NRR/JLD/JOMB, NRC Manager, Bureau of Nuclear Engineering - New Jersey Department of Environmental Protection Mayor of Lacey Township, Forked River, NJ

Enclosure Oyster Creek Nuclear Generating Station Sixth Six-Month Status Report for the Implementation of Order EA-12-049, Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events (10 pages)

Oyster Creek Nuclear Generating Station Sixth Six Month Status Report for the Implementation of FLEX February 2016 Enclosure Oyster Creek Nuclear Generating Sixth Six Month Status Report for the Implementation of Order EA-12-049, Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events

1. Introduction Oyster Creek Nuclear Generating Station developed an Overall Integrated Plan (Reference 1),

documenting the diverse and flexible strategies (FLEX), in response to NRC Order Number EA-12-049, Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events (Reference 2). This enclosure provides an update of milestone accomplishments since submittal of the last status report including any changes to the compliance method, schedule, or need for relief I relaxation and the basis, if any.

2. Milestone Accomplishments

a. Modification development is complete.

b. National SAFER Response Center procedures are implemented.

3. Milestone Schedule Status The following provides an update to Attachment 2 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.

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

Milestone Schedule Revised Target Target Activity Activity Status Completion Completion Date Date Submit 60 Day Status Report October 2012 Complete Submit Overall Integrated Plan February 2013 Complete Contract with RRC Complete Submit 6 Month Updates:

Update 1 August 2013 Complete Update 2 February 2014 Complete Update 3 August 2014 Complete Update 4 February 2015 Complete Update 5 August 2015 Complete Complete with Update 6 February 2016 this submittal Update 7 August 2016 Not Started I of 10

Oyster Creek Nuclear Generating Station Sixth Six Month Status Report for the Implementation of FLEX February 2016 Revised Target Target Activity Activity Status Completion Completion Date Date Submit Completion Report October 2016 Not Started Target Revised Target Activity Completion Activity Status Completion Date Date Modification Development Revised in Modification Development August 2016 Complete August 2013 (All FLEX Phases) update Modification Implementation October 2016 Not Started No Change (All FLEX Phases)

Procedures:

Create Site-Specific Procedures October 2016 Started No Change Validate Procedures October 2016 Not Started No Change (NEI 12-06, Sect. 11.4.3)

Create Maintenance Procedures October 2016 Started No Change Perform Staffing Analysis June 2016 Not Started No Change Storage Plan and Construction October 2016 Started No Change FLEX Equipment Acquisition October 2016 Started No Change Training Completion October 2016 Not Started No Change Revised in National SAFER Response Center December 2015 Complete August 2014 update Full Site FLEX Implementation October 2016 Started No Change Changes to Compliance Method Note: No changes to the compliance method were identified in this update. The four changes listed below were previously identified in the fifth six month update.

Change 1:

General Integrated Plan Elements BWR - Provide a sequence of events and identify any time constraint required for success including the technical basis for the time constraint. - Item 3; Control Room crew has assessed SBO and plant conditions and declares an Extended Loss of AC Power (ELAP) event.

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Oyster Creek Nuclear Generating Station Sixth Six Month Status Report for the Implementation of FLEX February 2016 Reason for Change:

A review of the timeline and procedure actions has determined the declaration of an ELAP event does not have to occur until 60 minutes into the event. Actions from the SBO procedure will be sufficient to guide the crew actions and deployment of equipment.

Change 2:

General Integrated Plan Elements BWR - Provide a sequence of events and identify any time constraint required for success including the technical basis for the time constraint. - Items 8 and 15; Continue to maintain critical functions of core cooling (via IC and FLEX Pump injection), containment (via Isolation Condensers) and SFP cooling (FLEX pump injection to SFP).

Reason for Change:

The MAAP analysis (Reference 7) used to predict the peak containment parameters and establish the timing for possible containment venting has been revised. The revised MAAP does not indicate the need for containment venting. Revision 1 adds one (1) additional MAAP case that alters the time of external RPV injection and adjusts isolation condenser operation strategy to prevent collapsed water level in the RPV shroud from dropping below TAF.

o An assumption in the MAAP is the containment vent is opened when RPV level reaches TAF or to stay below the 35 psig containment design pressure as specified in each scenario. Each scenario was reviewed and Cases 5 through 7 require no containment venting. Case 7 will be used to establish the timeline for this event.

Change 3:

General Integrated Plan Elements BWR - Provide a sequence of events and identify any time constraint required for success including the technical basis for the time constraint. - Item 12; Commence injecting into the reactor using the FLEX pump and restore level to the normal band.

Reason for Change:

The MAAP analysis (Reference 7) used to predict the peak containment parameters and establish the timing for possible containment venting has been revised. The revised MAAP does not indicate the need for containment venting. Revision 1 adds one (1) additional MAAP case that alters the time of external RPV injection and adjusts isolation condenser operation strategy to prevent collapsed water level in the RPV shroud from dropping below TAF.

o An assumption in the MAAP analysis (Reference 7, Case 7) is the FLEX pump injection into the RPV is at 3.3 hours3.472222e-5 days 8.333333e-4 hours 4.960317e-6 weeks 1.1415e-6 months (100 gpm at 160 psig). Prior Case 6 resulted in the collapsed water level in the RPV shroud dropping below TAF for a short period of time. This was the result of RPV water inventory contraction due to the simultaneous operation of both ICs at t=3.8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months . Case 7 provides a strategy that prevents collapsed shroud level from dropping below TAF by initiating external RPV injection earlier (3.3. hours versus 3.8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months for Case 6) and delay of simultaneous IC operation until the normal RPV water level recovers sometime after 3.3 hours3.472222e-5 days 8.333333e-4 hours 4.960317e-6 weeks 1.1415e-6 months .

Change 4:

The following changes were made to the Overall Integrated Plan (OIP) conceptual drawings submitted in the Second Six-Month Status Report (Reference 4) to reflect present design:

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Oyster Creek Nuclear Generating Station Sixth Six Month Status Report for the Implementation of FLEX February 2016

Addition of Core Spray System 2 for core injection for improved control of Reactor water level per ECR OC-14-00025.

Removal of Feedwater (FW) System for core injection due to inability of available flow to open the FW Check valves and, due to high flow rates causing difficulty in managing Reactor water level per ECR-OC-14-00025.

Removal of Containment Spray System for injection due to the flow path delivering flow rates that are not high enough to fill the spray headers per ECR-OC-14-00025.

4. Need for Relief/Relaxation and Basis for the Relief/Relaxation None

5. Open Items and Confirmatory items from Overall Integrated Plan and Interim Safety Evaluation The following tables provide a summary of the open and Confirmatory items documented in the Overall Integrated Plan or the Draft Safety Evaluation (SE) and the status of each item.

Section Overall Integrated Plan Open Items Status Reference Sequence of The times to complete actions in the Events Started events Timeline are based on operating judgment, (p. 10-12) conceptual designs, and current supporting analyses. The final timeline will be time validated once detailed designs are completed and procedures developed.

Sequence of Initial evaluations were used to determine the Started events fuel pool timelines. Formal calculations will be (p. 11-12) performed to validate this information during development of the spent fuel pool cooling strategy detailed design.

Identify how 1. Transportation routes will be developed 1. Started strategies will from the equipment storage area to the 2. Started be deployed in FLEX staging areas. 3. Started all modes 2. Identification of storage areas is an open (p. 13) item.

3. An administrative program will be developed to ensure pathways remain clear or compensatory actions will be implemented to ensure all strategies can be deployed during all modes of operation.

Identify how An administrative program for FLEX to Started the establish responsibilities, and testing &

programmatic maintenance requirements will be controls will implemented.

be met (p. 14) 4of10

Oyster Creek Nuclear Generating Station Sixth Six Month Status Report for the Implementation of FLEX February 2016 Maintain Complete an evaluation of the spent fuel pool Started Spent Fuel area for steam and condensation.

Pool Cooling (p.36)

Safety Evaluate the habitability conditions for the Started Functions Main Control Room and develop a strategy to Support maintain habitability.

(p. 44)

Safety Develop a procedure to prop open battery Tracked in Interim Safety Evaluation Functions room doors upon energizing the battery Confirmatory Items reference section Support chargers to prevent a buildup of hydrogen in 3.2.4.2.A (p. 44) the battery rooms.

Sequence of Issuance of BWROG document NEDC-33771P, Complete 11 events (p. 10) GEH Evaluation of FLEX Implementation Reference 3 Guidelines" on 01/31/2013 did not allow sufficient time to perform the analysis of the deviations between Exelon's engineering analyses and the analyses contained in the BWROG document prior to commencing regulatory reviews of the Integrated Plan.

Baseline In response to NRC Order EA-12-049 and Started coping implementation of EPG Rev 3, containment Reference 10: Oyster Creek capability venting is not required for FLEX. Modifications Request for Extension to Comply (p. 27) and capabilities of the hardened Vent system with NRC Order EA-13-109 will be IAW QC extension request for EA (06-02-14, RS-14-081) 109.

Reference 11: Oyster Creek Vent Order Extension Request RAI Response (09-26-14, RS-14-243)

Reference 12: Oyster Creek Vent Order Extension Request Supplemental RAI Response (11 14, RS-14-318)

Section Interim Safety Evaluation Open Items Status Reference None None NA 5of10

Oyster Creek Nuclear Generating Station Sixth Six Month Status Report for the Implementation of FLEX February 2016 Section Interim Safety Evaluation Confirmatory Items Status Reference 3.1.1.3.A Confirm that the licensee develops a reference Started source describing what actions should be taken if instruments were lost due to a seismic event.

3.1.1.4.A Confirm the location of the off-site staging area(s) Started and acceptability of the access routes considering the seismic, flooding, high wind and snow, ice and extreme cold hazard.

3.1.2.2.A Confirm that if temporary flood barriers are used, Complete they are stored such that they can be easily Reference 6 deployed.

3.1.3.1.A Verify that the separation of the planned outdoor Started storage areas is sufficient to preclude damage of both sets of FLEX equipment.

3.1.3.1.B Confirm qualified storage locations for the Started hurricane and extreme snow and icing hazards are identified.

3.1.3.2.A Confirm that the licensee's evaluation of water Started quality and resulting action are sufficient to preclude blockage of flow to the core or SFP.

3.2.1.1.A Confirm that benchmarks are identified and Complete discussed that demonstrate that MAAP is an Reference 6 appropriate code for the simulation of an ELAP event at your facility.

3.2.1.1.B Confirm that the collapsed level remains above Complete Top of Active Fuel (TAF) and the cool down rate Reference 6 remains within technical specifications limits.

3.2.1.1.C Confirm that MAAP is used in accordance with Complete Sections 4.1, 4.2, 4.3, 4.4, and 4.5 of the June 2013 Reference 6 position paper.

3.2.1.1.D Confirm that the licensee identifies and justifies Complete the subset of key modeling parameters cited from Reference 6 Tables 4-1 through 4-6 of the "MAAP Application Guidance, Desktop Reference for Using MAAP Software, Revision 2" (Electric Power Research Institute Report 1020236). This should include response at a plant-specific level regarding specific modeling options and parameter choices for key models that would be expected to substantially 6of10

Oyster Creek Nuclear Generating Station Sixth Six Month Status Report for the Implementation of FLEX February 2016 Section Interim Safety Evaluation Confirmatory Items Status Reference affect the ELAP analysis performed for that licensee's plant. Although some suggested key phenomena are identified below, other parameters considered important in the simulation of the ELAP event by the vendor I licensee should also be included.

a. Nodalization

b. General two-phase flow modeling

c. Modeling of heat transfer and losses

d. Choked flow

e. Vent line pressure losses

f. Decay heat (fission products I actinides I etc.)

3.2.1.1.E Confirm that the specific MAAP analysis case that Complete was used to validate the timing of mitigating Reference 6 strategies in the Integrated Plan is identified and available on the ePortal for NRC staff to view.

Alternately, a comparable level of information may be included in the supplemental response. In either case, the analysis should include a plot of the collapsed vessel level to confirm that TAF is not reached (the elevation of the TAF should be provided) and a plot of the temperature cool down to confirm that the cool down is within technical specifications limits.

3.2.1.3.A The SOE final timeline will be time validated once Not Started detailed designs are completed and procedures are developed. The licensee should provide the results for NRC staff review.

3.2.4.2.A The licensee stated that battery room ventilation Started to address high/low temperatures and prevention of hydrogen buildup will be addressed through procedure changes and that the proposed methods of ventilation, open doors and fans, will be confirmed during the detailed design process.

3.2.4.4.A The NRC staff has reviewed the licensee Started communications assessment (ADAMS Accession Nos. ML12306A199 and ML13056A135) in response to the March 12, 2012 S0.54(f) request for information letter for OCNGS and, as documented in the staff analysis (ADAMS Accession No. ML13114A067) has determined that the assessment for communications is reasonable, 7of10

Oyster Creek Nuclear Generating Station Sixth Six Month Status Report for the Implementation of FLEX February 2016 Section Interim Safety Evaluation Confirmatory Items Status Reference and the analyzed existing systems, proposed enhancements, and interim measures will help to ensure that communications are maintained.

Verification of required upgrades has been identified as a confirmatory item.

3.2.4.8.A Confirm the procedures to isolate the vital USS's Started from the generator.

3.2.4.8.A Ensure that the diesel generator is equipped with Complete - Reference 8 - Fleet overload protection in the generator skid. FLEX Generator Specification No.

FUKGEN-001, Rev 2; Reference 9 -

Cummins NPower, LLC, Exelon Fukushima FLEX SOOKW Portable Generator Engineering Submittal Report, Rev. 0.

3.2.4.8.B Confirm/review technical basis and/or Complete calculations provided as basis for the generator Reference 13 sizing.

3.2.4.10.A Confirm completion of analysis to determine Started battery coping time with no actions and with battery load shed.

3.4.A NEI 12-06, Section 12.2 lists minimum capabilities Complete - Oyster Creek has for offsite resources for which each Licensee executed contractual agreements should establish the availability. Confirm with Pooled Equipment Inventory implementation of Guidelines 2 through 10 in NEI Company (PEICo) which allows for the 12-06, Section 12.2. capabilities (considerations) in Section 12.2 of NEI 12-06. National SAFER Response Center, NSRC, submitted a paper to the NRC detailing the capability and ability to meet all of NEI 12-06, Section 12.2 considerations (ML1425A223).

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Oyster Creek Nuclear Generating Station Sixth Six Month Status Report for the Implementation of FLEX February 2016

6. Potential Draft Safety Evaluation Impacts Note: No additional Potential Draft Safety Evaluation Impacts were identified in this update. The Potential Draft Safety Evaluation Impact stated below was previously identified in the fifth six month update.

ECR (Engineering Change Request) OC 14-00025 update to the Oyster Creek Interim Staff Response (Reference ML14030A513) related to the DIP for makeup to the Reactor Vessel and Recirculation Pump's seal leakage states the following:

"Make up to the Reactor Vessel is commenced 3.3 hours3.472222e-5 days 8.333333e-4 hours 4.960317e-6 weeks 1.1415e-6 months (based on the revised MAAP run, Reference 5 to ECR QC 14-00025) from the start of the event. The flow rate credited by the MAAP is 100 gpm. It is postulated that this flow rate will be delivered, at the same time as the makeup to the Isolation Condensers (IC). This is a reasonable maximum requirement as the Isolation Condenser makeup will be cycled on and off as needed and RPV makeup will be slowed considerably when Reactor Level is brought back into its normal band.

Once re-established, the amount of makeup is to account for inventory loss. A maximum make up flow of 50 gpm to the Reactor Pressure Vessel is required to keep the core covered. This is derived from a 5 gpm leak rate from each of the five Reactor Recirculation Pumps' seals when the pumps stop because of the Extended Loss of AC Power (ELAP) that is postulated. (5 pumps X 5 gpm = 25 gpm total).

The leakage rate is derived from Atomic Energy Canada Limited (AECL) reports ET-S-331, Testing of the CAN2A Seal Cartridge under Station Blackout Conditions, and ET-S-426, Testing of the CAN2A Seal Cartridge under Station Blackout Conditions - Phase 2 (References 2.9 and 2.9A to ECR OC 14-00025).

Note that the AECL reports were done for Nine Mile Point. The Recirculation Pumps at Oyster Creek use the same AECL seals. Attachment 12 to ECR OC 14-00025 provides data that the Nine Mile Point Unit 1 seals use the same design as Oyster Creek.

To the 25 gpm, the normal allowable leak rate is added. Tech Spec 3.3.D, allows a 5 gpm Unidentified Leakage limit and a 25 gpm Total (Identified + Unidentified) leakage limit. Therefore, makeup rate is 50 gpm. Further, four of the five Reactor Recirculation pumps will be isolated (per the time line in the OIP) at three hours. Therefore, actual lost inventory at three hours postulating maximum Tech Spec allowable leakage is 30 gpm."

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

1. Exelon Generation Company, LLC letter to NRC, Oyster Creek Nuclear Generating Station, Overall Integrated Plan in Response to March 12, 2012 Commission Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events (Order Number EA-12-049)," dated February 28, 2013 (RS-13-023)

2. NRC Order Number EA-12-049, "Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events," dated March 12, 2012

3. Exelon Generation Company, LLC letter to NRC, Oyster Creek Nuclear Generating Station, First Six-Month Status Report in Response to March 12, 2012 Commission Order Modifying Licenses with 9of10

Oyster Creek Nuclear Generating Station Sixth Six Month Status Report for the Implementation of FLEX February 2016 Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events (Order EA-12-049), dated August 28, 2013 (RS-13-125)

4. Exelon Generation Company, LLC letter to NRC, Oyster Creek Nuclear Generating Station, Second Six-Month Status Report in Response to March 12, 2012 Commission Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events (Order EA-12-049), dated February 28, 2014 (RS-14-013)

5. Exelon Generation Company, LLC letter to NRC, Oyster Creek Nuclear Generating Station, Third Six-Month Status Report in Response to March 12, 2012 Commission Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events (Order EA-12-049), dated August 28, 2014 (RS-14-211)

6. Exelon Generation Company, LLC letter to NRC, Oyster Creek Nuclear Generating Station, Fourth Six-Month Status Report in Response to March 12, 2012 Commission Order Modifying licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events (Order EA-12-049), dated February 27, 2015 (RS-15-022)

7. MAAP Analysis Oyster Creek Generating Station Document Number OC-MISC-010

8. Fleet FLEX Generator Specification No. FUKGEN-001, Rev. 2

9. Cummins NPower, LLC, Exelon Fukushima FLEX 500KW Portable Generator Engineering Submittal Report, Rev. 0.

10. Oyster Creek Request for Extension to Comply with NRC Order EA-13-109, dated June 2, 2014 (RS-14-081)

11. Oyster Creek Vent Order Extension Request RAI Response, dated September 26, 2014 (RS-14-243)

12. Oyster Creek Vent Order Extension Request Supplemental RAI Response, dated November 25, 2014 (RS-14-318)

13. Oyster Creek AR 2386806 EOl, Fukushima FLEX Electrical Mitigation Strategy Technical Evaluation

8. Attachments None 10of10