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# Frequently Asked Questions About Reactor Decommissioning

These FAQ are from Staff Responses to Frequently Asked Questions Concerning Decommissioning of Nuclear Power Reactors (**NUREG-1628**). The questions were taken from a variety of sources over several years, including written inquiries to the NRC and questions asked at public meetings and during informal discussions with NRC staff. In responding to the questions, the NRC staff attempted to answer in a clear and non-technical form.

In addition, in response to the recent increase in public attention regarding decommissioning, the NRC staff has created a **Decommissioning Communication Strategy** to capture many of the recent questions and concerns raised regarding the decommissioning process The NRC staff will keep this document updated as plants continue to transition into decommissioning and will eventually incorporate these new FAQs into a revision to NUREG-1628.

For information on materials sites, please refer to the **Decommissioning Lessons Learned** page.

**Public and Environmental Impacts**
        - Is worker safety considered in the planning for and review of decommissioning?
        - Is public safety considered in the planning for and review of decommissioning?
        - Is there a difference between the human response to manmade ionizing radiation and the natural background radiation we are all exposed to as a result of us living on this planet?
        - Is there a safe dose of ionizing radiation?
        - What does the BEIR VII report say about a safe dose of ionizing radiation?
        - What are safe doses of radiation exposure for children? Developing fetuses? Women?
        - Do NRC limits take into account other sources of pollution, radioactive or otherwise? How do other types of pollution exacerbate risks posed by radiation?
        - What health studies have been conducted on tritium? What evidence does NRC have that the 'reviews' they have done have the statistical power to identify health impacts? How do they deconvolute impacts from other sources of radiation and pollution?
        - Are impacts to flora and fauna considered in determining safe levels?

**General Questions**
        - How is decommissioning defined?
        - Why are power reactors decommissioned?
        - Are there alternatives to decommissioning?
        - How is a nuclear power plant decommissioned?

**Effluent Release**
        - What is an effluent release?
        - Who is responsible for determining how the liquid effluents at a Nuclear Power Plant under decommissioning are removed from the site?
        - How is effluent release monitored?
        - What are the NRC’s Regulations for Radioactive Release?

**NRC's Regulations**
        - Does the licensee have an NRC license during the decommissioning process?
        - What happens if the licensee's license expires before the decommissioning process is concluded?
        - Are there any restrictions on what the licensee can do with the site after decommissioning is completed and the NRC has terminated the license? Does the NRC review these activities?
        - Who regulates the decommissioning process?
        - What publications contain the regulations for decommissioning?
        - When regulatory actions are required to decommission a nuclear facility?
        - How do NRC limits compare to the findings of the National Academy of Sciences 2022 report "Developing a Long-Term Strategy for Low-Dose Radiation Research in the United States"?
        - Air quality standards have tightened over the last few decades. Why haven’t radiological exposure standards tightened as well?

**Decommissioning Inspection**
        - What are the goals of the inspection program at nuclear power plants undergoing decommissioning?
        - How does decommissioning end? Who decides that the decommissioning is complete?

**Residual Radioactivity**
        - What are the criteria for residual radioactivity at the site at the end of decommissioning, assuming that the licensee is planning for unrestricted use of the site?
        - What are the criteria for residual radioactivity at the site at the end of decommissioning, assuming that the licensee is planning for restricted use of the site?
        - How can a plant site be used after decommissioning is completed?
        - Will there be continued environmental monitoring of the site and the offsite areas to measure releases of radioactive material during the decommissioning process?

**Decommissioning Cost**
        - How much does it cost to decommission a nuclear power plant?
        - How does the NRC ensure that the licensee will have the money needed for decommissioning?

**Public Involvement**
        - What meetings are planned to keep the public informed? 
        - How do I comment on the decommissioning process?
        - Other than the public meeting, how can I get information about a nuclear power plant?

Index to All Frequently Asked Questions Pages

**Is worker safety considered in the planning for and review of decommissioning?**

Yes. Worker safety is considered in terms of the radiological hazard (their exposure to radiation) and industrial safety.

**Is public safety considered in the planning for and review of decommissioning?**

Yes. Public safety is a major concern, even though the potential for hazards to the public from the decommissioning process and accidents is much less than it is when the facility is operating.

**Is there a difference between the human response to manmade ionizing radiation and the natural background radiation we are all exposed to as a result of us living on this planet?**

Background and manmade radiation may come from different sources, but both affect us in the same way. The dose assessment process considers the differences in the type and energy of ionizing radiation and converts the factors into a standard term called effective dose.

**Is there a safe dose of ionizing radiation?**

While the NRC does not have a definition of a safe dose of ionizing radiation, the NRC regulations limit the amount of radiation to which the public can be exposed as a result of NRC licensed activities. Studies have been unable to identify any negative health effects at those dose limits.

NRC’s regulations (at 10 CFR Part 20) contain standards for the protection of licensees, their employees, and the general public against radiation hazards arising out of the possession or use NRC licensed material. In establishing these basic radiation protection standards and the associated regulatory limits (10 CFR Part 20), the NRC has generally followed the recommendations and consensus standards of the International Commission on Radiological Protection (ICRP), and its U.S. counterpart, the National Council on Radiation Protection & Measurements (NCRP) in ICRP Publication 26. These organizations believe that the best model for predicting radiation induced effects is a linear, no threshold (LNT) dose response model in which every increment of radiation dose, no matter how small, is assumed to constitute an increased cancer risk for humans.

The NRC's regulatory limits for ionizing radiation exposure were established at sufficiently low levels for which biological damage, such as cataracts, or health effects, such as cancer, would not be observed. The standards provide what is considered to be "a very substantial margin of safety for exposed individuals" (22 FR 548 and 25 FR 10914). The NRC limits for members of the general public are further reduced to a small fraction of those for occupational radiation workers. Additionally, NRC regulations require licensees to minimize the exposure received using the as low as reasonable achievable (ALARA) concept. For example, the NRC's public dose limit is 100 mrem/year and, as a result of the licensees ALARA practices, the average individual living in the vicinity of a nuclear power plant receives less than 1 mrem/year. It is also helpful to keep in mind that we are surrounded by natural sources of ionizing radiation. Our annual exposure to cosmic, terrestrial, and medical sources of radiation (approximately 620 mrem/year) is many times greater than the public's exposure to radiation from activities licensed by the NRC, especially those of operating and decommissioning nuclear power plants.

**What does the BEIR VII report say about a safe dose of ionizing radiation?**

Some interested stakeholders in NRC licensing actions make a claim that "there is no safe dose of ionizing radiation" and will sometimes provide a four-page summary of the BEIR VII report "Health Risks from Exposure to Low-Level Ionizing Radiation" and assert that this report concludes that "there is no safe dose of ionizing radiation". It is unfortunate that this report's findings are often not fully understood or are sometimes misrepresented. To quote that report summary:

The BEIR VII report concludes that the current scientific evidence is consistent with the hypothesis that, at the low doses of interest in this report, there is a linear dose-response relationship between exposure to ionizing radiation and the development of solid cancers in humans. It is unlikely that there is a threshold below which cancers are not induced, but at low doses the number of radiation induced cancers will be small.

The BEIR VII conclusions are properly interpreted to mean that the current regulatory assumption (that all ionizing radiation exposures entail some risk) continues to be supported by the scientific evidence. These risks approach zero as the radiation exposures approach zero. At no time did the authors of the BEIR VII report say there is no "safe" dose of radiation. Neither of the BEIR V (1990) and BEIR VII (2006) reports use the word safe in its publication when describing radiation exposure. The one possible exception in the BEIR V report was a caveat about using the Linear No-Threshold (LNT) model in that "the linear model, if not always correct, is likely to err on the safe side."

The NRC also notes that some risk does not mean "unsafe", and that many routine daily activities involve significant risks and yet are considered to be "safe". For example, the risks of death from a motor-vehicle accident is 1 in 93 yet driving is considered to be a fundamentally safe activity. We can also see that the annual ionizing radiation exposure from the terrestrial radiation from naturally occurring radioactive materials in the ground varies from 23 mrem/year in Florida to 90 mrem/year on the Colorado Plateau. Moving from Orlando to Denver would entail additional radiation exposure of 67 mrem every year, and yet this routine relocation would not be considered unsafe, even for children.

The NRC has generally followed the basic radiation protection recommendations of the ICRP and its U.S. counterpart, the NCRP, in formulating basic radiation protection standards (10 CFR Part 20). These organizations believe the best model for predicting radiation induced effects is a linear, no threshold (LNT) dose response model. The NRC adopted a system of radiological protection which provides "adequate protection of public health and safety." All exposures should be justified, and our regulations require that radiation exposures be optimized in order to minimize the exposure received using the ALARA concept.

See FAQ Question "Is there a safe dose of ionizing radiation?" for more information.

**What are safe doses of radiation exposure for children? Developing fetuses? Women?**

The NRC and the EPA each establish federal regulations protecting the environment. In effect, the NRC regulates radioactive emissions from nuclear power plants, and EPA regulates the radioactive materials once in the environment. The NRC staff continually reviews and maintains awareness of the recommendations of the ICRP and NCRP. NRC also participates in the federal agencies ISCORS with the EPA, Department of Energy, Department of Defense, Department of Homeland Security, Department of Transportation, Occupational Safety and Health Administration and Department of Health and Human Services.

According to NCRP Report Number 174, Preconception and Prenatal Radiation Exposure: Health Effects and Protective Guidance (2013), doses below 10 Rem (10,000 mrem) should not increase the risk of reproductive effects (birth defects and miscarriage). The current regulatory limit to a member of the public, including pregnant women, is 100 times less than this value. The ICRP and NRCP have ongoing efforts to investigate sex and age-based exposures, which continue to be evaluated by the NRC.

The NRC system of radiation protection requires that every reasonable effort to maintain dose as far below the dose limits as possible, or As Low As Is Reasonably Achievable (ALARA) be implemented. The NRC regulations provide adequate protection to all populations and are consistent with national and international standard setting bodies. In perspective, the actual doses to the maximum exposed member of the public (located adjacent to nuclear plants) are in the order of 100 -1,000 times lower than radiation safety standards.

**Do NRC limits take into account other sources of pollution, radioactive or otherwise? How do other types of pollution exacerbate risks posed by radiation?**

NRC dose limits are established consistent with EPA’s Federal guidance and are set to prevent observable impacts. Therefore, it is extremely difficult to detect any observable health effects. Dose limits are inclusive of all sources of radiation generated by the licensee. The NRC does not have jurisdiction over non-radioactive pollutants.

**What health studies have been conducted on tritium? What evidence does NRC have that the 'reviews' they have done have the statistical power to identify health impacts? How do they deconvolute impacts from other sources of radiation and pollution?**

The ICRP, NCRP, and NAS have reviewed many health studies. The NCRP determined that doses from nuclear power plant releases account for less than 0.1 percent of the total background dose. See NCRP Report No. 160, "Ionizing Radiation Exposure of the Population of the United States." The NRC does not do its own health studies but has examined previous abnormal liquid releases of radioactivity from U.S. commercial nuclear power plants. For example, in 2006, an NRC task force made findings and recommendations related to tritium releases which are available on the NRC website's page on groundwater contamination. The NRC staff updated the information again in a 2012 paper to the Commission. In 2016, the NRC staff recommended, and the Commission agreed, that current regulatory requirements were adequate to protect public health and safety and no additional requirements or guidance was warranted.

**Are impacts to flora and fauna considered in determining safe levels?**

No. The current levels are much lower than the levels that would result in any potential significant impacts to flora and fauna. The United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) has several reports related to the potential impact of radiation to flora and fauna. The USCEAR benchmarks were that chronic dose rates of less than 100 μGy/h (10 mrem/hr) to the most highly exposed individual organisms would be unlikely to have significant effects for population integrity of most terrestrial communities, and that maximum dose rates of 400 μGy/h (40 mrem/hr) to any individual in aquatic populations of organisms would be unlikely to have any detrimental effects at the population level.

In addition to the completed reports listed below, UNSCEAR is carrying out the following evaluations:
        - Public exposure to ionizing radiation from natural and other sources (initiated in 2020 with planned completion in 2024);
        - Epidemiological studies of radiation and cancer (initiated in 2019 with planned completion in 2025);

UNSCEAR References:
        - UNSCEAR, 2000. Sources and Effects of Ionizing Radiation. United Nations Scientific Committee on the Effects of Atomic Radiation Report to the General Assembly with Scientific Annexes.Vol. II: Effects. United Nations, New York, NY.
        - UNSCEAR, 2001. Hereditary Effects of Ionizing Radiation. United Nations Scientific Committee on the Effects of Atomic Radiation Report to the General Assembly with Scientific Annexes. United Nations, New York, NY.
        - UNSCEAR, 2008. Effects of Ionizing Radiation. United Nations Scientific Committee on the Effects of Atomic Radiation Report to the General Assembly with Scientific Annexes. United Nations, New York, NY.

**How is decommissioning defined?**

Title 10 of the Code of Federal Regulations, Section 50.2 (10 CFR 50.2) defines decommissioning as the safe removal of a facility from service and reduction of residual radioactivity to a level that permits termination of the NRC license.

**Why are power reactors decommissioned?**

As one of the conditions for an operating license, the NRC requires the licensee to decommission the nuclear plant after it ceases power operations. This requirement is based on the need to reduce the amount of radioactive material at the site to ensure public health and safety as well as protection of the environment.

**Are there alternatives to decommissioning?**

NRC's regulations require decommissioning at the end of the licensing period. The alternative to decommissioning is "no action," implying that a licensee abandons or leaves a facility after ceasing operations. This is not a viable alternative to decommissioning.

Decommissioning restores a nuclear facility to such a condition that there is no unacceptable risk from the facility to public health and safety or the environment. To ensure that the risk from a facility is within acceptable bounds, some action is required. If nuclear power plants were not decommissioned, they could degrade and become radiological hazards.

**How is a nuclear power plant decommissioned?**

Decommissioning involves removing the spent fuel (the fuel that has been in the reactor vessel), dismantling any systems or components containing activation products (such as the reactor vessel and primary loop), and cleaning up or dismantling contaminated materials from the facility. All activated materials generally have to be removed from the site and shipped to a waste processing, storage, or disposal facility. Contaminated materials may either be cleaned of contamination on site; the contaminated sections may be cut off and removed (leaving most of the component intact in the facility); or they may be removed and shipped to a waste processing, storage, or disposal facility. The licensee decides how to decontaminate material; the decision is usually based on the amount of contamination, the ease with which it can be removed, and the cost to remove the contamination versus the cost to ship the entire structure or component to a waste disposal site.

**What is an effluent release?**

Generally, when the NRC refers to effluent releases, it refers to radioactive material released into the environment as a gaseous or liquid discharge. Effluent releases are done while the Nuclear Power Plant is in operation and as it transitions to decommissioning. Environmental discharges (liquid and airborne) are subject to a variety of regulations, depending upon the nature of the discharge, including by the NRC, the EPA, and potentially, state and local laws.

**Who is responsible for determining how the liquid effluents at a Nuclear Power Plant under decommissioning are removed from the site?**

The licensee in charge of the Decommissioning is responsible for determining how it will manage radioactive material in its liquid effluent. The licensee may elect to use any of the methods allowed under the NRC's regulations, which allow discharge, shipment for disposal, or evaporation of the liquid and disposal of the resulting solid waste. The licensee is required to keep records of releases, along with documentation that demonstrates that it is meeting license conditions and applicable regulations for the releases. The NRC will review the licensee’s Off-Site Dose Calculation Manual, which the licensee must use to comply with its license. The NRC also routinely inspects the licensee for compliance with NRC regulations, their license, and approved manuals and procedures.

**How is effluent release monitored?**

NRC-licensed facilities may discharge radiological wastes (i.e., gases, liquids, or particulates) into the environment provided that dose limits to members of the public (see 10 CFR 20.1301) are not exceeded and that doses are maintained As Low As is Reasonably Achievable (ALARA).

Effluent radiation monitors are used at facilities, such as Nuclear Power Plants undergoing decommissioning, with discrete discharge points, such as the plant stack for airborne releases or a discharge conduit for liquid releases. The licensee samples the releases and measures the radiation in the samples at the release points, where the concentration is the highest. In addition, the NRC provides oversight, through its inspectors, of the licensee’s compliance with the NRC regulations related to effluent release, monitoring, and reporting to ensure public health and safety associated with operation of the facility. As part of the monitoring process, the NRC also requires annual reports from the licensee that itemize shipment of radioactive waste to licensed waste repositories.

**What are the NRC’s Regulations for Radioactive Release?**

Information on the NRC's Regulations for Radioactive Release:
        - The NRC’s regulations governing radioactive releases are based on dose to the public, not the volume of the release (see 10 CFR 20.2001; 20.1301; 20.2003; 20.2004; 20.2005; and 10 CFR 35.92).
        - The same requirements apply to decommissioning and operating reactors.
        - During decommissioning, the NRC continues to inspect the licensee’s effluent and environmental programs at least annually.

Key Technical NRC Regulatory Guides (RG) on Radiological Effluents:
        - RG 1.21, Measuring, Evaluating, and Reporting Radioactive Materials in Liquid and Gaseous Effluents and Solid Waste, addresses the measuring, evaluating, and reporting of effluent releases, solid radioactive waste shipments, and public dose from nuclear power plants.
        - RG 1.109, Calculation of Annual Doses to Man from Routine Releases of Reactor Effluents for the Purpose of Evaluating Compliance with 10 CFR Part 50, Appendix I, provides the detailed implementation guidance for demonstrating that radioactive effluents conform to the ALARA design objectives of 10 CFR Part 50, Appendix I.
        - RG 4.1, Radiological Environmental Monitoring for Nuclear Power Plants, discusses principles and concepts important to environmental monitoring at nuclear power plants. The RG provides guidance on Radiological Environmental Monitoring Programs (REMP) for routinely monitored exposure pathways and annual reporting to the NRC.

Regulations on effluent releases and regulatory guides are available on the NRC public website.

**Does the licensee have an NRC license during the decommissioning process?**

Yes. The NRC license (called a "Part 50 license" in reference to the location of the corresponding regulations in the Code of Federal Regulations) is not terminated until the licensee can demonstrate that it meets the criteria for site release in the regulations. The NRC verifies the licensee's final radiation survey by reviewing it and/or conducting a separate survey. In addition, the licensee must demonstrate that the facility has been dismantled in accordance with the approved license termination plan.

**What happens if the licensee's license expires before the decommissioning process is concluded?**

The decommissioning regulations state that the license for a facility that has permanently ceased operations will continue beyond the expiration date to authorize possession of the facility until the Commission notifies the licensee in writing that the license is terminated. During this period, the licensee will take actions necessary to decommission and decontaminate the facility and will continue to maintain the facility in a safe condition.

**Are there any restrictions on what the licensee can do with the site after decommissioning is completed and the NRC has terminated the license? Does the NRC review these activities?**

Frequently, after the radiological decommissioning process and the termination of the license, the licensee will remove nonradioactive facilities or will remodel some of the remaining buildings for other industrial uses. Activities that take place after the licensee has demonstrated that the radiological hazard has been removed, and after the license has been terminated, are not within the jurisdiction of the NRC. The NRC has no oversight of these activities once the license is terminated.

**Who regulates the decommissioning process?**

The NRC regulates and provides oversight of the radiological aspect of the decommissioning process until it agrees to terminate the license. The mission of the NRC is to ensure adequate protection of public health and safety, protection of the environment, and protection and safeguarding of nuclear materials and nuclear power plants in the interest of national security. NRC's functions include (1) licensing nuclear facilities, (2) developing regulations and regulatory guidance, (3) conducting inspections and enforcement activities to ensure compliance with the regulations, (4) reviewing changes to the license, changes to licensee programs, and unreviewed safety questions, and (5) providing licensees with information that would improve their performance.

**What publications contain the regulations for decommissioning?**

Regulations regarding the decommissioning of NRC-licensed plants appear in the Code of Federal Regulations. The Code of Federal Regulations is a codification of the general and permanent rules published in the *Federal Register* by the executive departments and agencies of the Federal Government.

The regulations related to the decommissioning of power reactors are included in Title 10, "Energy," Chapter I—Nuclear Regulatory Commission. For example, Part 20, "Standards for Protection Against Radiation"; Part 50, "Domestic Licensing of Production and Utilization Facilities"; and Part 51, "Environmental Protection Regulations for Domestic Licensing and Related Regulatory Functions."

The subparts related to decommissioning are 20.1402, "Radiological criteria for unrestricted use"; 20.1403, "Criteria for license termination under restricted conditions"; 20.1404, "Alternate criteria for license termination"; 20.1405, "Public notification and public participation"; 20.1406, "Minimization of contamination"; 50.75, "Reporting and record keeping for decommissioning planning"; 50.82, "Termination of license"; 51.53, "Post-construction environmental reports"; and 51.95, "Post-construction environmental impact statements." These regulations state the technical and financial criteria for decommissioning licensed nuclear facilities. They address decommissioning, planning needs, timing, funding methods, and environmental review requirements.

**What regulatory actions are required to decommission a nuclear facility?**

The regulations specify actions that the NRC and the licensee must take to decommission a nuclear power plant. Once the decision is made to permanently cease operations, the licensee must notify the NRC in writing within 30 days. The notification must contain the date when the power generation operations stopped or will stop. The licensee must remove the fuel from the reactor and submit a written certification to the NRC confirming its action. (There is no time limit specified before the fuel must be removed or the corresponding certification received by the NRC.) Once this certification has been submitted, the licensee is no longer permitted to operate the reactor or to put fuel into the reactor vessel. This also reduces the licensee's annual license fee to the NRC and eliminates the need to adhere to certain requirements that are followed only during reactor operations. The licensee must submit a Post-Shutdown Decommissioning Activities Report (PSDAR) to the NRC and the affected State(s) no later than 2 years after permanent cessation of operations. The PSDAR must
        - describe the planned decommissioning activities;
        - contain a schedule for the accomplishment of significant milestones;
        - provide an estimate of expected cost;
        - document that environmental impacts associated with site-specific decommissioning activities have been considered in previously approved environmental impact statements.

If the environmental impacts that are identified have not been considered in existing environmental assessments, the licensee must address the impacts in a request for a license amendment regarding the activities. The licensee also must submit a supplement to its environmental report that relates to the additional impacts. The NRC will review this environmental assessment or supplement to the environmental statement in conjunction with its review of the license amendment request.

After receiving a PSDAR, the NRC publishes a notice of receipt, makes the PSDAR available for public review and comment, and holds a public meeting near the plant to discuss the licensee's plans.

Although the NRC will determine if the information is consistent with the regulations, NRC approval of the PSDAR is not required. However, should the NRC determine that the information requirements of the regulations are not met in the PSDAR, the NRC will inform the licensee in writing of the deficiencies and require that they be addressed before the licensee initiates any major decommissioning activities.

On completion of the required submittals, and allowing for a 90-day waiting period after submittal of the PSDAR, the licensee may start major decommissioning activities. Major decommissioning activities include the following:
        - permanent removal of major radioactive components, such as the reactor vessel, steam generators, or other components that are comparably radioactive;
        - permanent changes to the containment structure;
        - dismantling components resulting in "greater than Class C" waste.

Decommissioning activities conducted without specific prior NRC approval must not preclude release of the site for possible unrestricted use, must not result in there being no reasonable assurance that adequate funds will be available for decommissioning, and must not cause any significant environmental impact not previously reviewed. If any decommissioning activity does not meet these terms, the licensee is required to submit a license amendment request before conducting the activity; this would provide an opportunity for a public hearing.

Activities that are not considered to be "major decommissioning activities" may be performed in accordance with the license and technical specifications in effect for the facility even before the end of the 90-day waiting period. Allowable activities would include such routine items as maintenance and low-level waste disposal of small radioactive components.

Within 2 years of permanent cessation of operations, the licensees must submit a site-specific cost estimate for the decommissioning project. The licensee is prohibited from using the full amount of money that was accumulated during operations for the decommissioning process until the site-specific cost estimate is submitted to the NRC.

Within 2 years following permanent cessation of operation licenses are also required to submit for review and preliminary approval a description of how they intend to manage and provide funding for the management of irradiated fuel until title to the fuel is transferred to the Department of Energy (DOE).

Unless the licensee receives permission to the contrary, the site must be decommissioned within 60 years. The licensee remains accountable to the NRC until decommissioning is completed and the license is terminated. To conclude its obligations, the licensee must submit a license termination plan (LTP).

The LTP must be submitted at least 2 years before the termination date. It must include the following:
        - a site characterization;
        - identification of remaining dismantlement activities;
        - plans for site remediation;
        - detailed plans for the final survey of residual contamination on the site
        - a description of the end-use of the site (if restricted use is proposed, a description of institutional controls and maintenance and surveillance programs is needed);
        - an updated site-specific estimate of remaining decommissioning costs;
        - a supplement to the environmental report.

After receiving the LTP, the NRC will place a notice of receipt in the *Federal Register* and will make the plan available to the public for comment. The NRC will schedule a public meeting near the facility to discuss the plan's contents with the public. The NRC will also offer an opportunity for a public hearing on the license amendment associated with the LTP. If the LTP demonstrates that the remainder of decommissioning activities will be performed in accordance with the NRC's regulations, is not detrimental to the health and safety of the public, and does not have a significant effect on the quality of the environment, the Commission will approve the plan by a license amendment (subject to whatever conditions and limitations the NRC deems appropriate and necessary). Once the license amendment is granted, the licensee may achieve license termination by successfully demonstrating implementation of the license termination plan as approved by the NRC.

At the end of the LTP process, if the NRC determines that the remaining dismantlement has been performed in accordance with the approved LTP and if the final radiation survey and associated documentation demonstrate that the facility and site are suitable for release, the Commission will terminate the license; the decommissioning process is considered complete.

**How do NRC limits compare to the findings of the National Academy of Sciences 2022 report "Developing a Long-Term Strategy for Low-Dose Radiation Research in the United States"?**

The National Academy of Sciences (NAS) 2022 report proposed a research strategy for studying low dose radiation research, potentially leading to a revision of federal radiation safety standards. The report discussed studying the longstanding concerns that exposure to low doses below a 10 rem (10,000 mrem) threshold can affect human health.

It is important to note that the radiation exposures to the public from radioactive effluents are approximately 100 to 1,000 times lower than this "low dose threshold of 10 rem" (10,000 mrem) proposed for study by the NAS 2022 report. Any results from such studies would be assessed by the NAS to determine if changes to the system of radiation protection is warranted.

NRC staff continually reviews and maintains awareness of the recommendations on safety standards for protection against radiation of the International Commission on Radiological Protection (ICRP) and National Council on Radiation Protection and Measurements (NCRP). The NRC, along with other select Federal agencies, participates in the Interagency Steering Committee on Radiation Standards (ISCORS). ISCORS facilitates consensus on acceptable levels of radiation risk to the public and workers and promotes consistent risk approaches in setting and implementing standards for protection from ionizing radiation. ISCORS accomplishes this consensus by holding a series of internal subcommittee and working group meetings to discuss potential changes. ISCORS considers stakeholder input when deciding how to update or incorporate any new recommendations.

**Air quality standards have tightened over the last few decades. Why haven’t radiological exposure standards tightened as well?**

The existing air quality standards for radioactive materials have not changed because they continue to provide adequate protection. The maximum exposed, hypothetical member of the public, living adjacent to a nuclear power plant, receives a very small fraction, 100 – 1,000 times lower, than airborne safety standards in the regulations in 10 CFR Part 20, Appendix B. Therefore, there is no need to change the standards.

The NRC staff maintains awareness of both ICRP recommendations and NCRP reports to inform both ongoing actions and future updates to the NRC’s requirements for dose limits to workers and members of the public. The NRC formally reviewed its regulations and initiated rulemaking in 2012 to revise radiation protection regulations and guidance to achieve a closer alignment with the dose terminology and methodology of more recent ICRP recommendations, among other changes.

However, in December 2016, this rulemaking effort was discontinued (81 FR 95410) based on the conclusion that the current NRC regulatory framework continues to provide adequate protection of the health and safety of workers, the public, and the environment. Additionally, in 2021 the NRC reviewed three petitions for rulemaking requesting that the NRC amend its radiation protection regulations in 10 CFR Part 20 based on what the petitioners asserted was new science and evidence that contradicts the linear no-threshold (LNT) dose-effect model that serves as the basis for the NRC's radiation protection regulations. The NRC evaluated these requests against the current radiation protection requirements and determined that the LNT model continues to provide a sound regulatory basis for minimizing the risk of unnecessary radiation exposure to both members of the public and radiation workers. Therefore the three petitions for rulemaking were denied; for more information see 86 FR 45923.

**What are the goals of the inspection program at nuclear power plants undergoing decommissioning?**

The goals of the inspection program at nuclear power plants undergoing decommissioning are to
        -  obtain sufficient information through direct observation and verification to determine if decommissioning is being conducted safely, if the spent nuclear fuel is being stored safely, and if activities at the site are being conducted in accordance with all applicable regulations and commitments; 
        -  determine if the administrative controls that the licensee has in place are adequate and in accordance with regulatory requirements (the controls include self-assessment, audits and corrective actions, design control, safety review, maintenance and surveillance, radiation protection, and effluent controls); 
        -  identify any significant declining performance trends and verify that the licensee has taken actions to reverse any trend. 

**How does decommissioning end? Who decides that the decommissioning is complete?**

Licensees must submit an application for license termination at least 2 years before the requested termination date of the license. The license termination plan (LTP) must include
        - a site characterization;
        - identification of remaining dismantlement activities;
        - plans for site remediation;
        - detailed plans for the final survey of residual contamination on the site;
        - a method for demonstrating compliance with the radiological criteria for license termination (For restricted release, the LTP should include a description of the site's end use and documentation on public consultation, institutional controls, and financial assurance needed to comply with the requirements for license termination for restricted release or alternative criteria.);
        - an updated site-specific estimate of remaining decommissioning costs;
        - a supplement to the environmental report that describes any new information or significant environmental changes associated with the licensee's proposed termination activities.

After receiving the LTP, the NRC places a notice of the receipt of the plan in the *Federal Register* and makes the plan available to the public for comment. The NRC also schedules a public meeting near the facility to discuss the plan's contents with the public. Because this is an action that involves a license amendment, there is an opportunity for members of the public to request a hearing. If the LTP demonstrates that the remainder of decommissioning activities will be performed in accordance with the NRC's regulations, is not detrimental to the health and safety of the public, and does not have a significant effect on the quality of the environment, then the Commission approves the plan by a license amendment, subject to whatever conditions and limitations the NRC deems appropriate and necessary. At this point, the licensee may achieve license termination by successfully demonstrating implementation of the LTP, as approved by NRC.

The NRC will determine if the remaining dismantlement is performed in accordance with the approved LTP. If this is the case, and if the final radiation survey and associated documentation demonstrate that the facility and site are suitable for release, then the Commission terminates the license, and the decommissioning process is considered to have been completed.

**What are the criteria for residual radioactivity at the site at the end of decommissioning, assuming that the licensee is planning for *unrestricted* use of the site?**

The Commission has established a dose of 25 millirem (0.25 millisievert) per year total effective dose equivalent to an average member of the critical group as an acceptable criterion for release of any site for unrestricted use. The dose limit includes the dose from drinking groundwater. The licensee will be required to show that the site can meet this criterion before the license will be terminated for unrestricted use. In addition, the licensee will need to show that the amounts of residual radioactivity have been reduced to levels that are "as low as reasonably achievable." This concept, known as ALARA, means that all doses are to be reduced below required levels to the lowest possible level considering economic and societal factors. Determination of levels that are ALARA must take into account consideration of any detriments, such as deaths from transportation accidents that are potential results from decontamination and waste disposal.

**What are the criteria for residual radioactivity at the site at the end of decommissioning, assuming that the licensee is planning for *restricted* use of the site?**

The Commission's criteria for restricted use of the site are more complex than for unrestricted use and are tiered. Residual radioactivity at the site must have been reduced so that there would be reasonable assurance that the total effective dose equivalent from the residual radioactivity to the average member of the critical group would not exceed 25 millirem (0.25 millisievert) per year with institutional controls in place and either 100 millirem (1 millisievert) or 500 millirem (5 millisievert) per year with no institutional controls. Institutional controls include engineered controls (such as fences) and restrictions on the site's deed (e.g., parks or farms are not allowed). Institutional control could include ownership by the Federal or State government, thus providing for a legal mechanism to restrict public access.

For the **100 millirem (1 millisievert) per year** case, the licensee must demonstrate the following:
        -  Further reductions in residual radioactivity would result in net public or environmental harm, or they were not made because the residual levels are ALARA, taking into account the consideration of any detriments, such as traffic accidents, that are potential results from decontamination and waste disposal. 
        -  Provisions have been made for legally enforceable institutional controls to provide assurance that the 25 millirem (0.25 millisievert) per year average dose to the average member of the critical group will not be exceeded. 
        -  Funds are in an account segregated from other assets and outside of the licensee's administrative controls that will be used to pay for any necessary control and maintenance of the site, or that a surety method, insurance, or other guarantee method has been established. 
        -  The licensee has sought advice from affected parties and in seeking that advice provided for (1) participation by representatives of a broad cross section of community interests, (2) an opportunity for a comprehensive collective discussion on the issues, and (3) publicly available summary of the results of all such discussions. 

For the **500 millirem (5 millisievert) per year** case, the licensee must demonstrate the following:
        -  Further reductions in residual radioactivity necessary to comply with the 100-millirem-(1-millisievert)-per-year value are not technically achievable, are prohibitively expensive, or would result in net public or environmental harm. 
        -  Provisions have been made for legally enforceable and durable institutional controls (which may also include Federal, State, or local government control of sites), as well as provisions for a verification of the continued effectiveness of the institutional controls at the site every 5 years after license termination to ensure that the institutional controls are in place, and the restrictions are working. 
        -  There is sufficient financial assurance to enable a responsible government entity or independent third party to periodically recheck the site at least every 5 years to ensure that institutional controls remain in place to meet the 25-millirem-(0.25-millisievert)-per-year criterion. Sufficient financial assurance must also be provided to assume and carry out responsibilities for any necessary controls and maintenance of those controls. 
        -  The licensee has sought advice from affected parties and, in seeking that advice, provided for (1) participation by representatives of a broad cross section of community interests, (2) an opportunity for a comprehensive collective discussion on the issues, and (3) a publicly available summary of the results of all such discussions. 

In addition, there are alternate criteria for the case in which the **25-millirem-per-year** limit is found to be inappropriate. In this situation, it must be unlikely that the dose from all manmade sources combined, other than medical, would be more than 100 millirem (1 millisievert) per year. These alternate criteria are expected to be used only in rare cases. The licensee must
        -  submit an analysis of possible sources of exposure to provide assurance that public health and safety would continue to be protected; 
        -  demonstrate that it has employed, to the extent practical, restrictions on the site use; 
        -  reduce doses to ALARA levels, taking into consideration any detriments, such as traffic accidents, that are potential results from decontamination and waste disposal; 
        -  submit an LTP that specifies that it plans to decommission by using alternate criteria and documents how the licensee has sought and addressed advice from affected parties and, in seeking that advice, provided for (1) participation by representatives of a broad cross section of community interests, (2) an opportunity for a comprehensive collective discussion on the issues, and (3) a publicly available summary of the results of all such discussions. 

The use of alternate criteria to terminate a license requires the approval of the Commission after a consideration of the NRC staff's recommendations that address any comments provided by the U.S. Environmental Protection Agency or the public.

**How can a plant site be used after decommissioning is completed?**

If the license has been terminated and the site released for unrestricted use, any use is permitted. Possibilities include restoring the natural habitat, farming, and continuing industrial use (e.g., leaving buildings and installing a gas-, coal-, or oil-powered generating plant). If a site is being decommissioned under restricted- or alternate-release criteria, then NRC approval must be obtained, on a case-by-case basis, for the future uses of the plant site before the license is terminated.

**Will there be continued environmental monitoring of the site and the offsite areas to measure releases of radioactive material during the decommissioning process?**

Yes. The radiological environmental monitoring program that was in place at the plant will continue after the plant is shut down. The program will be modified to appropriately monitor the types of releases that may occur during decommissioning and to monitor results at appropriate intervals. Not all measurements will be made on a continuous basis. The licensee uses the results of the environmental monitoring program to calculate the dose to the public. They follow a procedure that is in the *Offsite Dose Calculation Manual*.

**How much does it cost to decommission a nuclear power plant?**

The total cost of decommissioning depends on many factors, including the sequence and timing of the various stages of the program, location of the facility, radioactive waste burial costs, and plans for spent fuel storage. The minimum amounts that are required for reasonable assurance of funds for decommissioning are $290 million for pressurized-water reactors and $370 million for boiling-water reactors. These costs are in 1999 dollars and are adjusted annually, as further specified in the regulations. These are minimum amounts to show reasonable assurance, rather than estimates, of what it would cost to decommission a specific nuclear reactor.

Actual site-specific costs incurred and estimated costs of decommissioning give a better indication of what the process costs. The Fort St. Vrain nuclear plant, which was a 330-megawatt-electric (MWe) high-temperature gas-cooled reactor, ceased power operations in 1989 and underwent immediate decontamination and dismantlement. The decommissioning effort was completed in late 1996, and the license was terminated. The total cost of decommissioning was $189 million.

The cost for decommissioning the Trojan nuclear plant (a 1130-MWe pressurized-water reactor) was estimated to be $210 million in 1993 dollars, which did not include $42 million for nonradioactive site remediation or $110 million for independent spent fuel storage installation and related fuel management. The Trojan plant planned an immediate decontamination and decommissioning from shutdown in 1993 to license termination in 2002.

The estimated cost for decommissioning the Haddam Neck nuclear plant, a 619-MWe pressurized-water reactor, is $344.4 million in 1996 dollars, not including $82.3 million in spent fuel storage costs (for a total of $426.7 million).

The estimated cost for decommissioning Maine Yankee, an 830-MWe pressurized-water reactor, was $274.9 million in 1997 dollars. This did not include costs for spent fuel management ($53.4 million) or for site restoration ($49.2 million), for a total of $377.6 million.

The estimated cost for decommissioning Big Rock Point, a 67-MWe boiling-water reactor, was $290 million in 1997 dollars.

The estimated cost for decommissioning Rancho Seco, a 913-MWe pressurized-water reactor was $441 million in 1995 dollars.

The estimated cost for decommissioning Yankee Rowe, a 175-MWe pressurized-water reactor was $306.4 million in 1995 dollars.

Decommissioning costs vary based on plant size and design, local labor and radiological waste burial costs, and the specific process that is being used for decommissioning.

**How does the NRC ensure that the licensee will have the money needed for decommissioning?**

Financial assurance is provided by the following methods:
> **Prepayment:** In this case, at the start of operations, the licensee deposits enough funds to pay the decommissioning costs into an account. The account is segregated from the licensee's other assets and remains outside the licensee's control of cash or liquid assets. Prepayment may be in the form of a trust, escrow account, government fund, certificate of deposit, or deposit of government securities.
**External sinking fund:** An external sinking fund is established and maintained by setting funds aside periodically into an account segregated from licensee assets and outside the licensee's control. The total amount of these funds will be sufficient to pay decommissioning costs when it is anticipated that the licensee will cease operations. An external sinking fund may be in the form of a trust, escrow account, government fund, certificate of deposit, or deposit of government securities.

**Surety method, insurance,** or **other guarantee method:** A surety method may be in the form of a surety bond, letter of credit, or line of credit. Any surety method or insurance used to provide financial assurance must be open-ended or, if written for a specific term, such as 5 years, must be renewed automatically. An exception is allowed when the issuer notifies the Commission, the beneficiary, and the licensee of its intent to not renew within 90 days or more preceding the renewal date. The surety or insurance must also provide that the full face amount be paid to the beneficiary automatically preceding the expiration date without proof of forfeiture if the licensee fails to provide a replacement acceptable to the Commission within 30 days after receipt of notification of cancellation. In addition, the surety or insurance must be payable to a trust established for decommissioning costs, and the trustee and trust must be acceptable to the Commission. The surety method or insurance must remain in effect until the Commission has terminated the license.

**What meetings are planned to keep the public informed?**

Two public meetings are required during the decommissioning process. The first occurs before major decommissioning activities begin, when the Post-Shutdown Decommissioning Activities Report is submitted. The second takes place when the license termination plan, which describes how the site will be returned to a condition that makes radiological controls no longer necessary, is submitted by the licensee. In both cases, the NRC will publish notifications of the public meetings in the *Federal Register* and in local media. The meetings will be held near the power plant to encourage local participation.

Although not required by the regulations, the NRC holds an initial public information meeting shortly after the licensee submits the certification of permanent cessation of operations. At the meeting, the NRC presents its process for regulating decommissioning, the licensee presents its plans for shutting down the facility and for decommissioning it (if any such plans have been made), and questions and comments from members of the public are addressed.

**How do I comment on the decommissioning process?**

You can submit comments and questions in writing to the NRC project manager for the facility. Comments and questions are also addressed at the public meeting following receipt of the Post-Shutdown Decommissioning Activities Report (PSDAR) or the license termination plan (LTP). A written transcript containing these comments is prepared. All comments and questions received at the meeting will be responded to in a memorandum that will be available to the public. Additionally, a memorandum that documents whether or not the information provided in the PSDAR satisfies NRC requirements will also be prepared and made available to the public. A sign-up sheet will be available at the public meeting for you to request copies of the memorandum, and the NRC project manager will mail a copy to those who request one. The address and telephone number for the specific NRC project manager will be published in the *Federal Register* along with the notice of the receipt of the PSDAR and the schedule of the public meeting.

**Other than the public meeting, how can I get information about a nuclear power plant?**

The NRC has many ways of keeping the public informed. These include printed materials, electronic access, and public meetings. NRC's Web site contains information of interest to the public. From the site, you can access the Electronic Reading Room.

A comprehensive list of information sources can be found in the Citizen's Guide to U.S. Nuclear Regulatory Commission Information (NUREG/BR-0010, Rev. 4).

The NRC maintains a Public Document Room near Washington, D.C.

Copies of documents can also be ordered from the Government Printing Office:

Superintendent of DocumentsU.S. Government Printing OfficeP.O. Box 37082Washington, DC 20402-9328Phone: 202-512-1800

Page Last Reviewed/Updated Monday, March 25, 2024

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Page Last Reviewed/Updated Monday, March 25, 2024