L-PI-15-086, 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
| ML15272A505 | |
| Person / Time | |
|---|---|
| Site: | Prairie Island  |
| Issue date: | 09/29/2015 |
| From: | Davison K Northern States Power Co, Xcel Energy |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| EA-12-049, L-PI-15-086, TAC MF0835 | |
| Download: ML15272A505 (8) | |
Text
Xcel Energy@
September 29, 2015 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Prairie Island Nuclear Generating Plant, Unit 2 Docket Number 50-306 Renewed Facility Operating License No. DPR-60 Prairie Island Nuclear Generating Plant 1717 Wakonade Drive East Welch, MN 55089 L-PI-15-086 10 CFR 2.202 10 CFR 50.4 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," Prairie Island Nuclear Generating Plant Unit 2 (TAG No. MF0835)
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. ML12054A735).
- 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 for Beyond-Design-Basis External Events (Order Number EA-12-049),"
dated February 26, 2013 (L-PI-13-007) (ADAMS Accession No. ML13060A379).
On March 12, 2012, the 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
Document Control Desk Page 2 the Prairie Island Nuclear Generating Plant (PINGP), Units 1 and 2. Specific requirements were outlined in Attachment 2 of Reference 1.
NSPM submitted the PINGP Overall Integrated Plan (OIP) (Reference 2) for compliance with NRC Order EA-12-049 by letter dated February 26, 2013. In accordance with Reference 1, licensees are required to complete full implementation with the Order no later than two refueling cycles after submittal of the OIP, or December 31, 2016, whichever comes first. The second refueling outage after the Reference 2 submittal for PINGP Unit 2 occurs in the Fall of 2015 (2R29).
Section IV of Reference 1 states that licensees proposing to deviate from requirements contained in NRC Order EA-12-049 may request that the Director, Office of Nuclear Reactor Regulation, relax those requirements.
The purpose of this letter is to request that the Director, Office of Nuclear Reactor Regulation, relax the schedule requirements for full implementation of NRC Order EA-12-049 for PINGP, Unit 2. This letter requests a schedule relaxation of 60 days following restart from the PINGP Fall 2015 refueling outage to allow for completion of the FLEX Storage Building that is needed to fully implement the strategies required by Order EA-12-049. NSPM's construction contractor has encountered significant construction delays caused by labor issues, weather, and complexities associated with first-time, unique building construction, which necessitate the need for schedule relaxation.
PINGP Unit 1 is currently scheduled for implementation of NRC Order EA-12-049 by Fall 2016, and therefore, is not impacted by this schedule relaxation request.
Please contact Lynne Gunderson, Licensing Engineer, at 651-267-7421, if additional information or clarification is required.
Document Control Desk Page 3 Summary of Commitments This letter makes no new commitments and no revisions to existing commitments.
NSPM considers that the requested relaxation would constitute a condition of compliance to the NRC Order EA-12-049 for PINGP Unit 2, and therefore, does not constitute a commitment.
I declare under penalty of perjury that the foregoing is true and correct.
Executed on September 29, 2015.
~~JJ~*~'-
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-15-086 Enclosure NSPM PRAIRIE ISLAND NUCLEAR GENERATING PLANT, UNIT 2 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" Relaxation Request In accordance with Section IV of NRC Order EA-12-049 (Reference 1) (FLEX), Northern States Power Minnesota (NSPM), doing business as Xcel Energy, hereby requests schedule relaxation of the Order requirement for the Prairie Island Nuclear Generating Plant (PINGP) Unit 2 to complete full implementation by no later than two refueling cycles after submittal of the overall integrated plan (OIP) required by Condition C.1.a of the Order, or December 31, 2016, whichever comes first. PINGP Unit 1 is not impacted by this schedule relaxation request.
Order Requirement from Which Relaxation Requested:
Condition IV.A.2 of NRC Order EA-12-049 requires full implementation of the Order requirements by "no later than two (2) refueling cycles after submittal of the overall integrated plan required by Condition C.1.a, or December 31, 2016, whichever comes first." NSPM submitted the PINGP OIP (Reference 2) for compliance with NRC Order EA-12-049 by letter dated February 26, 2013. For PINGP Unit 2, the current requirement for full implementation of NRC Order EA-12-049 is prior to restart from PINGP Unit 2 Refueling Outage in the Fall of 2015 (2R29). PINGP Unit 1 is currently scheduled for implementation of NRC Order EA-12-049 by Fall2016, and therefore, is not impacted by this schedule relaxation request and is not discussed further.
As described in Reference 4, NSPM has elected to build one FLEX Storage Building that meets the requirements of a robust structure in NEI 12-06, "Diverse and Flexible Coping Strategies (FLEX) Implementation Guide," Revision 0, (Reference 3) to store the FLEX portable pumps and generators and support equipment for PINGP, Units 1 and 2.
PINGP Unit 2 will be unable to demonstrate compliance to NRC Order EA-12-049 until:
- 1) the FLEX Storage Building is completed, 2) the FLEX equipment required to support the mitigating strategies is stored in the building, and 3) validation of equipment deployment time has been completed. As stated above, the current schedule requirement for PINGP Unit 2 implementation of NRC Order EA-12-049 is prior to startup from 2R29 in Fall 2015. Compliance with the NRC Order EA-12-049 schedule required for completion of implementation of mitigating strategies and equipment would result in significant hardship or unusual difficulty without a compensating increase in the level of safety. The requested relaxation would defer the compliance schedule date of NRC Order EA-12-049 for PINGP Unit 2 to no later than 60 days following restart from Page 1 of 5
L-PI-15-086 Enclosure NSPM 2R29. The requested relaxation would allow NSPM to complete construction of and move into the FLEX Storage Building as well as complete the necessary validation of equipment deployment time. Other NRC Order EA-12-049 requirements will be met by completion of 2R29 and additional interim actions will be taken during the relaxation period to provide additional margin with respect to deployment of FLEX equipment.
Justification for Relaxation Request:
NSPM's work to develop, implement, and verify FLEX guidance and strategies to maintain or restore core cooling, containment cooling, and spent fuel pool cooling was performed following the NRC-endorsed guidance in Nuclear Energy Institute (NEI) 12-06 (Reference 3). This work included the selection of type and location of the FLEX Storage Building currently under construction. The building is located inside the PINGP Owner Controlled Area, is being constructed of reinforced concrete, and is approximately 71' wide x 176' long x 21' high. This building has been designed to meet the site design basis for seismic, wind, tornado and tornado missiles as well as snow and ice loads (i.e., meets the Order requirement for reasonable protection and the NEI 12-06 requirement for robust). As stated in the OIP (Reference 2), the building will not be designed to withstand an external flood because the flood hazard has ample warning time. Additionally, the building will be equipped with heating and fans for internal environmental control. The PINGP FLEX Storage Building will store the equipment needed to support the FLEX mitigating strategies for PINGP Units 1 and 2.
The design and installation of the FLEX Storage Building was scheduled to be completed in time to allow placement of the equipment and validation of deployment strategies prior to start up from 2R29 in Fall 2015. However, NSPM has encountered significant construction delays. These delays include labor issues, weather delays, and the complexities associated with first-time, unique building construction. Each of these issues is discussed below:
Labor delays: The FLEX storage building is behind schedule due, in part, to poor craft attendance. The NSPM construction contractor experienced difficulties in obtaining and retaining qualified craft resources in a timely manner due to the high demand for craft in the immediate geographical area during the peak construction season. The construction contractor is currently taking every opportunity to work extended shifts (all available daylight hours) and weekends.
The construction contractor continues to work with the maximum staff that can safely work in the area available. There is no room for additional resources at the work site based on congestion due to craft, equipment, and materials.
Weather delays: Weather delays have exceeded what was expected by the construction contractor. Critical path construction activities cannot be completed by the construction contractor in the rain. Rebar cannot be placed during electrical storms due to safety concerns. Concrete pours can only be schedule and accomplished when weather is predicted to be clear. Initial schedules from Page 2 of 5
L-PI-15-086 Enclosure NSPM the construction contractor did not include weekend work. However, the construction contractor is now taking every opportunity to work extended shifts and weekends.
Constructability challenges: NSPM's construction contractor has noted that the PINGP FLEX building is a one-of-a-kind structure. The building design meets PINGP design basis requirements for seismic, wind, tornado and tornado missiles. The construction contractor under estimated the amount of materials and resources as well as the time needed to construct the building. Examples of this include:
o The initial estimates for amount of rebar and concrete were too low.
o The placement of rebar, concrete, and supporting equipment for the foundation, walls, and roof, has presented constructability challenges that were not anticipated. There have been numerous instances where the congestion of steel could have prohibited the concrete to flow during a pour and rebar was re-configured to allow a successful concrete pour.
o Installation of forms has taken three times longer than initially expected and the shoring and form removal is taking twice its scheduled time.
Despite the challenges and delays noted above, significant construction progress has been accomplished on the FLEX Storage Building. The construction contractor has continued to work extended hours, as the weather allows. As of September 25, 2015, the building is approximately 75 percent complete, having poured all four floor quadrants, 19 of 24 wall sections, and two of three roof sections.
To address the challenges described above, mitigate additional risks, and ensure that the FLEX Storage Building is completed within the requested relaxation period, construction schedule recovery plans have been in place since early July 2015. Even with recovery plans in place, the construction contractor continues to have issues with weather delays and obtaining and maintaining quality craft on the project. The following corrective actions continue to be implemented:
The construction contractor is working with the maximum staff that can safely work in the area.
The construction contractor is working all available day light hours and working weekends.
The construction contractor has provided on-site senior leadership to support construction activities since July 2015.
The current construction schedule indicates that the FLEX Storage Building will be complete by October 30, 2015. The current schedule for startup from 2R29 outage is scheduled for mid-November 2015. However, the risks of delays due to weather, installation challenges, completion of building testing, and moving FLEX equipment into the building could impact the outage startup date. Recognizing these potential risks and the historical productivity levels for the construction of the building, NSPM believes a 60-day relaxation request is necessary.
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L-PI-15-086 Enclosure NSPM The completion of the FLEX Storage Building is the only item affecting the compliance schedule. Other FLEX equipment and modifications required to implement the mitigation strategies required by NRC Order EA-12-049 are completed or will be completed prior to startup from the Fall 2015 refueling outage.
Based on the negative impact on the FLEX Storage Building construction progress and the possibility of further delays due to weather and installation challenges, NSPM is requesting that the Director, Office of Nuclear Reactor Regulation, relax the requirement for the schedule of compliance implementation for PINGP Unit 2, as prescribed in Section IV.A.2 of the Order. NSPM requests a relaxation of the PINGP Unit 2 FLEX compliance date to no later than 60 days following restart from the Fall 2015 refueling outage.
The requested relaxation of 60 days is adequate to recover from the identified delays and will allow the station to safely finish construction activities on the FLEX Storage Building, transfer of the FLEX equipment into the building, and finish validation of the equipment deployment. NSPM is confident that the FLEX Storage Building will be completed and become operational within the 60-day relaxation period.
The mitigation strategy requirements of NRC Order EA-12-049 provide additional defense-in-depth measures for mitigating consequences of a beyond-design-basis external event. At this time, NSPM is ready to implement the mitigating strategies required by Order EA-12-049 for PINGP Unit 2 during the Fall2015 refueling outage, with the exception of the FLEX Storage Building. During the relaxation period, the FLEX equipment associated with time constraints within the first 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of the ELAP will be staged at the designated deployment locations. The equipment necessary to meet time constraints in the first 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> includes the 300 kW generator and the associated cabling that repower both units' screen house and battery room motor control centers (Reference 2). Although the FLEX generators and cabling will be deployed in an outside environment, the equipment will be reasonably protected from applicable external events. Storing the FLEX generators at the deployment location rather than in a non-seismic structure protects the equipment from damage due to failure of the structure.
The PINGP site is outside the most probable timeframe for tornadoes during the 60-day relaxation period. Regarding flood conditions, NSPM uses early warning times to pre-stage equipment and prepare the site based on National Weather Service predictions.
Additionally, the generators are equipped with a cold weather package that would ensure the equipment is likely to function if necessary. The cold weather package includes a block heater, a battery charger, a space heater for interior temperature control, and a lube oil sump heater. Lastly, the trailer containing the cables will be protected from adverse impacts due to weather (e.g., rain, snow, and ice). The storage of the FLEX equipment associated with time constraints in the first 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of an ELAP at the deployment locations provides enhanced plant capability to mitigate a beyond-design-basis external event during the 60-day relaxation period. Therefore, the requested relaxation does not reduce nuclear safety or safe plant operations.
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L-PI-15-086 Enclosure
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Conclusion:==
NSPM As described above, compliance with the NRC Order EA-12-049 schedule required for completion of implementation of mitigation strategies and equipment would result in significant hardship or unusual difficulty without a compensating increase in the level of safety. A relaxation of 60 days is requested in order to allow: 1) completion of the FLEX Storage Building, 2) storage of FLEX equipment in the building, and 3) completion of necessary validation of deployment times. Therefore, in accordance with the provisions of Section IV of the Order, NSPM requests relaxation of the requirement described in Section IV.A.2 for PINGP Unit 2.
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. ML12054A735).
- 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 for Beyond-Design-Basis External Events (Order Number EA-12-049),"
dated February 26, 2013 (L-PI-13-007) (ADAMS Accession No. ML13060A379).
Implementation Guide," Revision 0, dated August 2012 (ADAMS Accession No. ML12242A378).
- 4. NSPM Letter to NRC, "Prairie Island Nuclear Generating Plant's 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-12-049)
(TAC Nos. MF0834 and MF0835)," dated August 25, 2015 (L-PI-15-065)
(ADAMS Accession No. ML15237A403).
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