L-PI-14-018, 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 No. EA-12-049)

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 No. EA-12-049)

ML14057A771
Person / Time
Site:	Prairie Island
Issue date:	02/26/2014
From:	Davison K Northern States Power Co, Xcel Energy
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
L-PI-14-018
Download: ML14057A771 (11)

Text

Xc I nergy Prairie Island Nuclear Generating Plant 1717 Wakonade Drive East Welch, MN 55089 February 26, 2014 L-PI-14-018 10 CFR 2.202 10 CFR 50.4 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Prairie Island Nuclear Generating Plant Units 1 and 2 Docket Numbers 50-282 and 50-306 Renewed Operating License Nos. DPR-42 and DPR-60 Prairie Island Nuclear Generating Plant's 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-12-049)

References:

1. NRC Order 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 (ADAMS Accession No. ML12054A736).

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 (ADAMS Accession No. ML12229A174).

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

Implementation Guide," Revision 0, dated August 2012 (ADAMS Accession No. ML12242A378).

4. NSPM Letter to NRC, "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 29, 2012 (ADAMS Accession No. ML12305A287).

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5. NSPM Letter to NRC, "Prairie Island Nuclear Generating Plant's 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 26, 2013 (ADAMS Accession No. ML13060A379).

6. NSPM Letter to NRC, "Prairie Island's 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-12-049)," dated August 26, 2013 (ADAMS Accession No. ML13239A094).

7. NRC Letter, "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," dated March 12, 2012 (ADAMS Accession No. ML12053A340).

On March 12, 2012, the Nuclear Regulatory Commission (NRC) staff issued Order EA-12-049, "Issuance of Order to Modify Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events," (Reference 1) to all NRC power reactor licensees and holders of construction permits in active or deferred status. Reference 1 was immediately effective and directed Northern States Power Company, a Minnesota corporation (NSPM), doing business as Xcel Energy, to develop, implement and maintain guidance and strategies to maintain or restore core cooling, containment and spent fuel pool cooling capabilities following a beyond-design-basis external event for the Prairie Island Nuclear Generating Plant (PINGP). Specific requirements are outlined in Attachment 2 of Reference 1.

Pursuant to Condition C of Section IV, Reference 1 required submission of an initial status report 60 days following issuance of the final interim staff guidance (ISG), an overall integrated plan, and status reports at six-month intervals following the submittal of the overall integrated plan. The ISG (Reference 2) endorses, with exceptions and clarifications, the industry guidance document, Nuclear Energy Institute (NEI) 12-06, "Diverse and Flexible Coping Strategies (FLEX) Implementation Guide," Revision 0 (Reference 3). Reference 4 provided the PINGP initial 60-day status report regarding mitigation strategies. Reference 5 provided the overall integrated plan for PINGP. The first six-month status report was provided in Reference 6.

The purpose of this letter is to provide the second six-month status report pursuant to Section IV, Condition C.2 of Reference 1, which delineates the progress made in implementing the requirements of the Reference 1 Order. The enclosed report provides an update of milestone accomplishments since the Reference 6 first status report was

Document Control Desk Page 3 submitted, including changes to the compliance method, schedule, or the need and basis for relief, if any.

As described in Reference 5, the PINGP FLEX mitigating strategies are based on the existing design basis flood as defined in PINGP's Updated Safety Analysis Report (USAR). NSPM is performing a Flood Hazard Reevaluation for PINGP pursuant to the 10 CFR 50.54(f) Information Request letter dated March 12, 2012 (Reference 7).

NSPM recognizes that the hazard reevaluation could result in calculated flood levels that exceed the current design basis, and that these flood levels could result in a reassessment of the strategies as described in the Reference 5 Overall Integrated Plan.

Any changes to the mitigating strategies that result from the flood hazard reevaluation results will be developed in accordance with Reference 7, and communicated via future six-month status reports.

Please contact Jennie Wike, Licensing Engineer, at 612-330-5788, if additional information or clarification is required.

Summary of Commitments This letter makes no new commitments and no revisions to existing commitments.

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

Executed on February 26, 2014.

Kevin Davison Site Vice President, Prairie Island Nuclear Generating Plant Northern States Power Company- Minnesota Enclosure cc: Administrator, Region Ill, USNRC Director of Nuclear Reactor Regulation (NRR), USNRC Project Manager, Prairie Island Nuclear Generating Plant, USNRC Resident Inspector, Prairie Island Nuclear Generating Plant, USNRC

L-PI-14-018 NSPM Enclosure Prairie Island Nuclear Generating Plant Units 1 and 2 Second Six-Month Status Report for Implementation of Order EA-12-049, Order Modifying Licenses with Regard to Requirernents for Mitigation Strategies for Beyond-Design-Basis External Events 1.0 Introduction The Nuclear Regulatory Commission (NRC) issued Order EA-12-049, "Issuance of Order to Modify Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events," on March 12, 2012 (Reference 1). The Order required licensees to develop, implement and maintain guidance and strategies to maintain or restore core cooling, containment and spent fuel pool cooling capabilities following a beyond-design-basis external event. The Order required licensees to submit an overall integrated plan, including a description of how the requirements in of the Order would be achieved. Northern States Power Company, a Minnesota corporation (NSPM), doing business as Xcel Energy, submitted the overall integrated plan (Reference 2) for the Prairie Island Nuclear Generating Plant (PINGP) on February 26, 2013. In accordance with Section IV, Condition C.2 of Reference 1, NSPM submitted the first six-month status report on August 26, 2013 (Reference 3).

This Enclosure provides the second six-month status report. This status report includes an update of milestone accomplishments since submittal of the previous six-month status report, including changes to the compliance method, schedule, or the need and basis for relief, if any.

2.0 Milestone Accomplishments The original milestone schedule with target dates was provided in Attachment 2 of the Reference 2 Enclosure. The following milestone has been completed since the previous status report was submitted and is current as of January 31, 2014.

• Commence Engineering Modification Design- Phase 2 & 3 (design process has started) 3.0 Milestone Schedule Status The following Table 1 provides an update of the milestone schedule for the overall integrated plan. This table includes a brief milestone status and a revised target date if the target date has changed. The target dates are planning dates subject to change as design and implementation details are developed.

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L-PI-14-01 B NSPM Enclosure

• Unit 1 Implementation Outage:

The target completion date for the Unit 1 implementation outage was changed from Spring 2016 to Fall 2016, due to changes in the PINGP refueling outage schedule for Unit 1.

• Validation Walk-Throughs:

The target completion date for the validation walk-throughs was changed from Spring 2016 to Fall 2016, due to changes in the PINGP refueling outage schedule for Unit 1.

• Submit Seventh Six-Month Status Report:

A target completion date for submitting a seventh six-month status report was added to the milestone schedule, due to changes in the PINGP refueling outage schedule for Unit 1.

• Submit Completion Report:

The target completion date for submitting the completion report was changed from August 2016 to December 2016, due to changes in the PINGP refueling outage schedule for Unit 1.

• Regional Response Center Operational:

The Regional Response Center will be operational by January 2015.

• Procure Equipment:

The target completion date for procuring equipment was changed from April 2014 to December 2014.

Table 1 - Overall Integrated Plan Milestone Schedule Target Activity Revised Milestone Completion Date Status Target Date Submit 60 Day Status Report October 2012 Complete Submit Overall Integrated Plan February 2013 Complete Submit First Six-Month Status August 2013 Complete Report Page 2 of 8

L-PI-14-018 NSPM Enclosure Table 1 *- Overall Integrated Plan Milestone Schedule Target Activity Revised Milestone Completion Date Status Target Date Commence Engineering September 2013 Complete Modification Design - Phase 2 & 3 Submit Second Six-Month Status February 2014 Complete with Report this submittal Regional Response Center TBD Started January 2015 Operational Procure Equipment April2014 Started December 2014 Submit Third Six-Month Status August 2014 Not Started Report Implement Storage December 2014 Not Started Issue Maintenance Procedures December 2014 Not Started Implement Training February 2015 Not Started Submit Fourth Six-Month Status February 2015 Not Started Report Submit Phase 2 Staffing Four months prior Not Started Assessment to 2R29 Implement Communication Four months prior Not Started Recommendations to 2R29 Issue Procedures updated for June 2015 Not Started FLEX strategies Submit Fifth Six-Month Status August2015 Not Started Report Unit 2 Implementation Outage Fall2015 Not Started Submit Sixth Six-Month Status February 2016 Not Started Report Unit 1 Implementation Outage Spring 2016 Not Started Fall2016 Page 3 of 8

L-PI-14-018 NSPM Enclosure Table 1 - Overall Integrated Plan Milestone Schedule Target Activity Revised Milestone Completion Date Status Target Date Validation Walk-throughs Spring 2016 Not Started Fall 2016 Submit Seventh Six-Month Status August 2016 Not Started Report Submit Completion Report August 2016 Not Started December 2016 4.0 Proposed Changes to Compliance Method There is one change to the compliance method documented in the overall integrated plan, and one update to information provided in the overall integrated plan regarding reactor coolant pump (RCP) seal design. The updated information on RCP seals and the change to the overall integrated plan are provided below.

RCP Low Leakage Seals The overall integrated plan submitted for PINGP included the following regarding RCP seal leakage assumptions:

NSPM is currently evaluating the option to credit the low leakage RCP seals for the ELAP [Extended Loss of A C Power] strategy, which could increase the coping time for Phase 1. Until a decision on the RCP seals is made, the strategy to Maintain RCS Inventory Control will be based on the existing RCP seal design (Reference 2).

In Reference 3, NSPM reported that the decision was made to install low leakage RCP seals at the PINGP. NSPM installed the first Flowserve N-9000 low leakage RCP seals into Unit 2 during the 2R28 refueling outage. NSPM will install the low leakage seals into Unit 1 during the next scheduled refueling outage 1R29 (Fall 2014). The Fl.owserve seals will impact the RCS Inventory Control strategy by increasing the coping time for Phase 1 and the timeframe needed to provide RCS makeup water. As NSPM noted in its overall integrated plan, the timeframe for providing RCS makeup water could be extended by several days if the RCP seal packages were replaced with a low leakage design. The specific impact of the Flowserve seals on the coping time is still under evaluation by the vendor and the industry. NSPM will confirm this expectation when the Flowserve information becomes available. Any strategy changes resulting from the Flowserve information will be communicated in future six-month status reports.

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L-PI-14-018 NSPM Enclosure Change to RCS Inventory Control Phase 2 and Phase 3 Strategies The overall integrated plan submitted for PINGP included the following regarding redundant Reactor Coolant System (RCS) makeup capabilities:

• A portable FLEX makeup water pump will be staged in the Auxiliary Building. A connection to each unit's Chemical Volume Control System (CVCS) will be provided from the portable electric pump. This connection is shown on Figure 4 in Attachment 3 [of Reference 2]. A portable FLEX diesel generator will be provided with cabling to power the electric FLEX makeup water pump. The FLEX makeup water pump will be sized to accommodate the makeup requirements for both units. WCAP-17601-P, Section 3.1.1, indicates that the makeup requirement for a single unit is 20 gpm at 1500 psig.

• An alternate RCS connection point will be provided in each unit's CVCS.

The alternate connection points, once identified in the design process, will be provided in a six month status report. Similar to the primary means, a portable FLEX makeup water pump will be staged in the Auxiliary Building.

A portable FLEX diesel generator will be provided with cabling to power the electric FLEX makeup water pump. [Reference 2]

The original RCS Inventory Control Phase 2 strategy, as described above, was to install a portable electric pump to provide RCS makeup. The original strategy proposed that the power supply to the portable electric pump would be provided by a portable generator located outside the building with cabling routed from the generator to the pump motor. The strategy in the overall integrated plan included providing a discharge tap into the CVCS and a suction source from the Reactor Water Storage Tank (RWST).

Subsequent to the submittal of Reference 2, NSPM decided to replace the Westinghouse RCP seals with the Flowserve N-9000 low leakage seal design with the Abeyance seal option. As NSPM noted in Reference 2, the timeframe for providing RCS makeup water could be extended by several days if the RCP seal packages were replaced with a low leakage design. Therefore, NSPM anticipates that the time required for providing RCS makeup water will be extended, such that a portable pump for supplying RCS makeup water will not be necessary until Phase 3. For the Phase 3 RCS Inventory Control strategy, the Regional Response Center will provide a portable RCS makeup pump in addition to the 4kV generator discussed in Reference 2.

The specific impact of the Flowserve seals on the RCS Inventory Control Phase 2 strategy is still under evaluation by the vendor and the industry. NSPM will confirm the coping time for the RCS Inventory Control Phase 2 strategy when the Flowserve information is available.

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L-PI-14-018 NSPM Enclosure As a backup strategy for Phase 2, NSPM will provide portable generators to repower the charging pumps, if needed in Phase 2. The charging purnps draw suction from the RWST and discharge directly to the RCS. Thus, no new suction or discharge connections will be required to use the charging pumps. There are three charging pumps installed at PINGP per unit. Two charging pumps are powered from one Motor Control Center (MCC) in each Unit (MCC 1K2 in Unit 1 and MCC 2K2 in Unit 2) and the third charging pump is powered from the opposite train MCC (MCC 1K1 in Unit 1 and MCC 2K1 in Unit 2). One charging pump in each Unit is sufficient to provide the required RCS makeup water.

The Phase 2 strategy for providing redundant RCS makeup capabilities, as a backup to the extended coping time granted by the RCP low leakage seals, will be revised in the overall integrated plan as follows:

• Installed charging pumps will be repowered using portable generators.

Unit 1 Motor Control Center (MCC) 1K2 and Unit 2 MCC 2K2 will be the preferred MCCs to repower. Repowering these MCCs will provide the option of repowering 11 or 13 Charging Pump [Unit 1] and either 21 or 23 Charging Pump [Unit 2].

• As an alternate connection point, MCC 1K1 [Unit 1] and MCC 2K1 [Unit 2]

will be repowered using portable generators. These MCCs will repower 12 and 22 Charging Pumps, respectively.

A mark-up of the overall integrated plan sections describing the Phase 2 and Phase 3 RCS Inventory Control strategies is provided in the attachment to this enclosure. These strategy changes will be incorporated into the final FLEX program document.

Justification for Change to RCS Inventory Control Phase 2 Strategy Table 3-2 of Nuclear Energy Institute (NEI) 12-06 (Reference 4) provides a summary of the FLEX baseline capabilities for Pressurized Water Reactors (PWR). One of the methods listed in Table 3-2 for RCS Inventory Control is "Low Leak RCP Seals and/or RCS high pressure makeup" (Reference 4). Additionally, the baseline capability for the RCS Inventory Control strategy is described as "Low-leak RCP seals and/or providing on-site high pressure RCS makeup capability" (Reference 4). NSPM's primary method of maintaining RCS inventory during Phase 2 will be through the use of the RCP low leakage seals, which complies with the baseline capability described in Table 3-2 of Reference 4. Repowering the charging pumps will provide an additional method for RCS inventory control during Phase 2, if needed.

The Charging Pumps are contained in the Auxiliary Building, which is a Class 1 structure with a design that is robust with respect to seismic events, floods, and high winds, and associated missiles. Therefore, the Charging Pumps would be available in an ELAP scenario to provide RCS makeup water, per the guidance in Section 3.2.1.3 of Reference 4.

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L-PI-t4-018 NSPM Enclosure As described in Reference 2, the PINGP FLEX mitigating strategies are based on the existing design basis flood as defined in PINGP's Updated Safety Analysis Report (USAR.). NSPM is performing a Flood Hazard Reevaluation for PINGP pursuant to the 10 CFR 50.54(f) Information Request letter dated March 12, 2012 (Reference 5).

NSPM recognizes that the hazard reevaluation could result in calculated flood levels that exceed the current design basis, and that these flood levels could result in a reassessment of the strategies as described in the Reference 2 Overall Integrated Plan.

Any changes to the mitigating strategies that result from the flood hazard reevaluation results will be developed in accordance with Reference 5, and communicated via future six-month status reports.

5.0 Need and Basis for Relief from the Requirements of the Order NSPM expects to comply with the Order implementation date and requirements. No relief from the requirements of the Order is required at this time.

6.0 Open Items from Overall Integrated Plan and Interim Staff Evaluation NSPM did not identify any open items in the PINGP mitigating strategies overall integrated plan. The overall integrated plan did contain future actions to ensure compliance with the Order. The future actions were identified internally and are being tracked through NSPM's corrective action program (CAP).

The Interim Staff Evaluation (ISE) has not been issued as of January 31, 2014. Closure of the ISE confirmatory and open items, when issued, will be tracked to closure in future status reports.

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

8.0 References The following references support the updates to the overall integrated plan described in this enclosure.

1. NRC Order 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 (ADAMS Accession No. ML12054A736).

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L-PI-14-018 NSPM Enclosure

2. NSPM Letter to NRC, "Prairie Island Nuclear Generating Plant's Overall Integrated Plan in Response to March 12, 2012 Commission Order Modifying Licenses with Regard to Requirements for Mitigation Strategies .t for Beyond-Design-Basis External Events (Order Number EA-12-049),"

dated February 26, 2013 (ADAMS Accession No. ML13060A379).

3. NSPM Letter to NRC, "Prairie Island's 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-12-049)," dated August 26, 2013 (ADAMS Accession No. ML13239A094).

4. NEI 12-06, "Diverse and Flexible Coping Strategies (FLEX) Implementation Guide," Revision 0, dated August 2012 (ADAMS Accession No. ML12242A378).

5. NRC Letter, "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," dated March 12, 2012 (ADAMS Accession No. ML12053A340).

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