ML24157A045
| ML24157A045 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 06/11/2024 |
| From: | Tanya Hood Reactor Decommissioning Branch |
| To: | |
| Shared Package | |
| ML24157A046 | List: |
| References | |
| Download: ML24157A045 (1) | |
Text
Enclosure 1 REQUEST FOR SUPPLEMENTAL INFORMATION General System Characterization Requirements by the U.S. Nuclear Regulatory Commission (NRC): The objective is to seek bulk or general information (e.g., sections, topics, basis, models, etc.) that is missing from the application. The focus is on the sufficiency of the information in the application.
Regulatory Requirement:
Title 10 of the U.S. Code of Federal Regulations (10 CFR) Paragraph 50.82(a)(1), Termination of license.
10 CFR Paragraph 50.82(a)(3), Termination of license 10 CFR Paragraph 50.4(b)(8), and 50.4(b)(9) Written communications.
10 CFR 50.12, Specific exemptions.
Regulatory Guidance:
Final Rule, General Requirements for Decommissioning Nuclear Facilities (Volume 53 of the FR, page 24018 (53 FR 24018; June 27, 1988))
Final Rule, Decommissioning of Nuclear Power Reactors (61 FR 39278; July 29, 1996)
NRC Regulatory Basis Document, Regulatory Improvements for Power Reactors Transitioning to Decommissioning, November 20, 2017 (ADAMS Accession No. ML17215A010).
U.S. NRC, Decommissioning of Nuclear Power Reactors, Regulatory Guidance (RG) 1.184, Washington, DC. (ADAMS Accession No. ML13144A840).
U.S. NRC, Standard Format and Content for Post-Shutdown Decommissioning Activities Report, RG 1.185, Washington, DC. (ADAMS Accession No. ML13140A038).
Basis: The regulations in 10 CFR 50.82(a)(3) require the decommissioning of a site to be completed within 60 years of permanent cessation of operations, while factoring in the possibility of the unavailability of waste disposal capacity and other site-specific factors affecting the licensee's capability to carry out decommissioning, including presence of other nuclear facilities at the site. The regulations do not specify a time limit on exemptions from the 60-year schedule; however, the Final Rule states the decommissioning will be completed without significant delay. Thus, the idea of a clear alternative schedule for relief at a multiunit site is after the U.S. NRC staff has reviewed the presented considerations based on proven specific factors of multisite interactions starting with the site in safe storage (SAFSTOR), the radioactive survey level, and the history of the updated final safety analysis report (UFSAR). In addition, the exemption must provide adequate discussion on the unit interactions.
The NRC staff will review and evaluate the alternative schedule exemption request on the specific connections between physical, functional, and spatial interactions, as the licensee provides sufficient information from a proactive decommissioning perspective. The entire site may not be granted the exemption, as a partial decommissioning of the site would meet the regulations. Thus, depending on the age of the site, conditions, and level of technical specification (TS) coverage for a beyond 60 years schedule the facility design must adequately
2 protect the environment, health and safety of workers and the public from the risk of accidental hazards related to a continued SAFSTOR site.
Request for Supplemental Information:
- 1. Security Measures Dresden Unit 1 is within the Dresden Physical Security Plan. The Physical Security Plan is inclusive of all three units and the adjacent Independent Spent Fuel Storage Installation (ISFSI).
The submittal does not describe which site security measures are associated with, or credited for, the security of Dresden Unit 1.
Describe the security measures for Dresden Unit 1 during the proposed extended period for decommissioning and provide the rationale for why these security measures are adequate for Dresden Unit 1 during safe storage (SAFSTOR) prior to dismantlement. Confirm that the security measures for Dresden Unit 1 during the proposed extended period of decommissioning would not adversely impact the physical protection of Dresden Units 2 and 3 and the associated ISFSI.
Describe whether there would be any impacts to the implementation of physical security for Dresden Units 2 and 3 that could not be reasonably mitigated during the partial or full decommissioning of Dresden Unit 1, if it were to be conducted as scheduled (i.e., without an exemption for an alternative schedule). If so, describe those impacts and why reasonable mitigation wouldnt be possible.
- 2. Decommissioning Measures Dresden Unit 1 has been monitored and controlled in SAFSTOR in accordance with the Facility Operating License, TSs as amended, and Decommissioning Plan.
Explain how decommissioning the remainder of Dresden Unit 1 would differ from the activities that occurred in the past with respect to safety of Dresden Units 2 and 3 and the licensees ability to maintain public health and safety. Include a discussion about modifications to these systems that can be done within the structure to decommission Dresden Unit 1 on schedule that does not increase risk to public health and safety due to structural complications and allow the licensee to maintain safety requirements without an alternative schedule necessary to protect public health and safety.
The application requested that the alternative decommissioning schedule for Dresden Unit 1 coincide with the schedule for Dresden Units 2 and 3, whichever is the first to transition to permanent cessation of operations. Please clarify the additional period of required surveillance and maintenance that would result from the alternative decommissioning schedule for Dresden Unit 1.
- 3. Mitigative Measures The list of combined and interactive support systems in Attachment 1 identifies the systems needed for Dresden Units 2 and 3 but does not mention any contingencies or mitigative measures needed for decommissioning of Dresden Unit 1 in the presence of Dresden Units 2 and 3. Please provide the following information related to Dresden Unit 1 decommissioning activities:
3 For Structures, Systems, and Components (SSCs) not related to safety, discuss the SSC impact to safe operations of the other nuclear facilities during decommissioning. Share what reasonable mitigative measures may be applied to all or any of the components related to the presence of other nuclear facilities that would result in not needing an alternative schedule for the purpose of maintaining public health and safety. Include what type of inadvertent damage would result due to decommissioning is envisioned that could not be reasonably mitigated.
- 4. Structures, Systems, and Components (SSCs) Interactions Provide an assessment of the physical, functional, and spatial interactions between decommissioning and operating unit SSCs, specifically those identified in the March 14, 2024, request, and why they merit an alternative schedule.
Provide or reference the document(s) that describe the potential risk to health and safety of the public due to decommissioning activities occurring alongside operating units, including potential decommissioning accidents that could affect the safe operation of the other nuclear facilities such as the ability to:
- Control reactor power
- Cool the fuel and
- Maintain containment (defense in depth).
- 5. Material Condition of SSCs Describe the current structural material condition of and any degradations and/or aging effects on Dresden Unit 1 SSCs that are important to safety. Describe the sources of residual radioactivity including the reactor vessel, reactor coolant system, containment, the spent fuel pool and spent fuel pool building, piping, tanks, and storage containers as applicable and how they would be controlled and contained over the proposed extended period of decommissioning.
Please provide information to support NRC staffs understanding of any maintenance, surveillance, inspection, or aging management performed to ensure the structural integrity of SSCs for Dresden Unit 1. Describe their adequacy to minimize the introduction of residual radioactivity into the site if the decommissioning schedule were extended. Discuss the visual inspections of SSCs of the UFSAR including the frequency, acceptance criteria, any findings of significance, and how findings are addressed.
- 6. Limitations Please characterize the limitations based on common decommissioning techniques used in industry today or the ones planned to be use and the degree of increased risk from Dresden Unit 1 decommissioning activities. Indicate whether this increased risk of performing decommissioning prohibit the ability to protect public health and safety.
- 7. Cumulative Damage or Duration The request does not cover the cumulative duration of demolition and dismantling activities.
Please provide the following information:
4
- a. Explain why the cumulative duration of demolition and dismantling activities would be less if all three units were decommissioned together.
- b. Explain how the factors stated apply to the criterion in 10 CFR 50.82(a)(3) about the need for an extended decommissioning schedule and would be necessary to protect public health and safety.
- 8. Decommissioning Conducted of the request states that Dresden Unit 1 facilities have been integrated into the support infrastructure and are actively utilized by Dresden Units 2 and 3. Please provide information on what decommissioning activities would be conducted and their duration, if the exemption from 10 CFR 50.82(a)(3) to complete decommissioning with an alternative schedule beyond 60 years were granted.
- 9. Hazards Assessment Explain the Dresden Unit 1 strategy to assess hazards of the containment structure for the proposed extended decommissioning schedule to ensure that the radioactive material would remain contained, including underground contamination through the groundwater pathway.
Identify whether there would be significant construction hazards during demolition of the radiologically contaminated buildings that require decommissioning due to the physical presence of other nuclear facilities that could not be reasonably mitigated.
- 10. Environmental Upon acceptance of the request, the NRC staff would prepare an environmental assessment (EA) pursuant to 10 CFR 51.21 and 51.30. To support a complete description in the EA of the proposed action, provide written information with the description of activities that would be conducted under the proposed action, such as maintenance, monitoring, and any planned physical changes (e.g., to structures or other features) related to Dresden Unit 1. Include a timeline for the activities from the present to the proposed decommissioning completion date.
- a. Provide a written description of the no action alternative along with a timeline. This includes activities to be conducted if the NRC denies the request for an alternative schedule, including (but not limited to) license termination plan submittal, infrastructure changes (e.g., new roads or structures) to accommodate decommissioning, any intensive decommissioning and demolition techniques, radioactive waste generation and disposal (estimate of rates and quantities), and plans for consultation with the State Historic Preservation Office regarding historic properties.
- b. Several factors may change for residual radioactivity in the groundwater system beyond 60 years, including changes to the groundwater system from changes in climatic conditions since the latest license renewal, cessation of pumping, or from partial decommissioning activities that alter surficial characteristics. These changes may lead to changes in flow direction and magnitude that may lead to new or additional mobilization or acceleration of migration of radionuclides offsite. These potential changes may be offset by reductions in groundwater contamination due to radionuclide decay and additional dilution associated with groundwater flushing and dispersion. Describe how climate change might impact erosion and containment of the radioactivity at Dresden Unit 1 over the proposed alternative decommissioning schedule. Describe any effects of
5 potential changes to the groundwater system beyond 60 years and whether those changes may lead to increased magnitude and spreading of groundwater residual radioactivity.
- 11. Updating Post-Shutdown Decommissioning Activities Report (PSDAR)
The purpose of the PSDAR is to provide the NRC and the public with a general overview of the licensees proposed decommissioning activities and to inform the NRC staff of the licensees expected activities and schedule so that the staff can plan for inspections and make decisions about its oversight activities. The PSDAR is also a mechanism that informs the public of the proposed decommissioning activities before the conduct of those activities. For licensees that submitted a decommissioning plan before August 28, 1996, the NRC considers the decommissioning plan and the associated environmental review to be the PSDAR submittal.
Decommissioning plans normally contain sufficient information to satisfy the requirements of the PSDAR. Licensees that have an approved decommissioning plan must submit an update for activities that they had not considered in their decommissioning plans to comply with 10 CFR 50.82(a)(7). The NRC encourages licensees to replace their decommissioning plans with a PSDAR update that uses the format and content specified in this document.