United States Nuclear Regulatory Commission - Protecting People and the Environment

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.

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

Index to All Frequently Asked Questions Pages

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.

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.

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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.

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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.

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.

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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.

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.

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.

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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

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Page Last Reviewed/Updated Wednesday, December 11, 2013