Nuclear Facility Decommissioning: Strategies, Waste, and Costs

The nuclear power plant decommissioning process is the technical and regulatory sequence a utility follows to retire a reactor, strip out radioactive contamination, and return the site to other uses. As of April 2026, roughly 21 power reactor sites in the United States are in some stage of decommissioning.¹ The work spans years or decades, and costs typically reach hundreds of millions of dollars per reactor. Federal regulations set a hard ceiling: 60 years from the day a plant stops operating to finish the job and terminate the license.

The Three Decommissioning Strategies

A utility shutting down a reactor picks from three recognized strategies. Each ends the same way, with residual radioactivity low enough to release the site, but the pace and method differ.

DECON is immediate dismantling. Work begins shortly after the reactor stops operating, with crews removing or decontaminating equipment, piping, and structural components as quickly as possible. It is the most common choice today, partly because staff who know the plant are still on hand and partly because communities generally want the land back sooner rather than later.

SAFSTOR is deferred dismantling. The plant is placed in a secure, monitored condition and left for an extended period while radioactivity naturally decays. This can last up to 60 years, reducing both worker exposure during eventual teardown and the volume of waste that has to be shipped away.²

ENTOMB seals radioactive materials inside a durable structure like concrete and lets radiation decay in place. No commercial power reactor in the United States has ever been entombed. The NRC has concluded that entombment is technically viable but that the existing framework, particularly the 60-year completion deadline, may need revision before it can serve as a standard alternative.³

Whichever path a licensee picks, all decommissioning must be completed within 60 years of the plant ceasing operations. Extensions are available only when necessary to protect public health and safety.² SAFSTOR cannot be stretched out indefinitely; the physical teardown has to happen.

The Post-Shutdown Decommissioning Activities Report

Before major work starts, the utility files a Post-Shutdown Decommissioning Activities Report (PSDAR) with the NRC. The report is due within two years after the plant permanently stops operating. It functions as the project’s master plan, laying out planned activities, a schedule with major milestones like reactor vessel removal or containment demolition, and a site-specific cost estimate that includes spent fuel management. The licensee must also show that the environmental impacts fall within the scope of prior environmental impact statements; anything new needs its own analysis.⁴

The NRC does not formally approve or reject the PSDAR. Staff review it for completeness and will tell the licensee if something is missing. Ninety days after the NRC receives the report, and once the licensee has certified permanent cessation of operations and permanent removal of fuel from the reactor vessel, major decommissioning activities may begin.⁵ The NRC publishes a notice of receipt, makes the report public, and holds a meeting near the plant so residents can ask questions.⁶

The Physical Work: Fuel, Decontamination, and Demolition

The first physical priority is spent nuclear fuel. Fresh out of the reactor, assemblies sit in the plant’s spent fuel pool for several years to cool. From there they are loaded into massive steel-and-concrete dry casks and transferred to an on-site Independent Spent Fuel Storage Installation (ISFSI). Moving this material is one of the most tightly controlled operations in the entire project, calling for specialized heavy-lift equipment and continuous radiation monitoring.

With fuel secured, crews turn to the primary cooling systems, often using chemical treatments to strip radioactive isotopes from the interior surfaces of pipes, pumps, and valves. Large components like steam generators and the reactor pressure vessel are cut apart and shipped to licensed low-level waste disposal facilities. Non-radioactive structures such as administrative buildings and cooling towers come down with conventional heavy equipment once they have been cleared of hazardous materials.

The most intensive phase is taking down the containment structure itself, which can involve cutting through several feet of reinforced concrete. As the physical work winds down, the licensee runs a Final Status Survey, a detailed radiological assessment of the whole site using highly sensitive instruments. That survey has to show that residual radioactivity meets the standard for whatever release category the licensee is pursuing.

Worker Radiation Dose Limits

Federal regulations cap the radiation dose workers can receive each year. Under 10 CFR Part 20, the total effective dose for any adult worker cannot exceed 5 rem (5,000 millirem) in a single year.⁷ Additional limits apply to specific body parts: 50 rem per year to any individual organ, 15 rem to the lens of the eye, and 50 rem to the skin. Workers under 18 face limits at one-tenth of the adult thresholds.

In practice, projects keep actual exposures well below the ceilings through careful planning. Crews rotate through high-radiation areas, use remote-controlled cutting tools where they can, and schedule the hottest work after natural decay has knocked dose rates down. That is one practical reason some utilities pick SAFSTOR: even a decade or two of waiting substantially reduces what workers absorb during demolition.

Radioactive Waste Classes and Disposal Capacity

Decommissioning produces large volumes of low-level radioactive waste, sorted into three classes based on the concentration and type of isotopes present. The class determines how the waste must be packaged, transported, and disposed of.

Class A is the least radioactive category, typically segregated from other waste at the disposal site. Most demolition debris falls here.
Class B has higher concentrations of shorter-lived isotopes and faces more demanding requirements for physical stability after disposal.
Class C is the most radioactive category still eligible for near-surface burial, with additional protective measures at the disposal facility to prevent inadvertent contact in the future.

Waste above Class C concentrations is generally not acceptable for near-surface disposal and requires separate federal handling.⁸

Only four licensed commercial disposal facilities in the country accept low-level radioactive waste, and not all of them are open to every generator. Clive, Utah accepts Class A waste from anywhere in the country. Barnwell, South Carolina and Richland, Washington handle all three classes but restrict access to generators within their respective interstate compacts. A fourth facility near Andrews, Texas accepts all three classes from Texas Compact members and from outside generators with compact permission.⁹ This limited capacity is a real constraint on timelines and costs, and waste transportation and disposal fees take a significant share of every project’s budget.

Spent Fuel and the Federal Repository Problem

The hardest long-term problem is spent nuclear fuel. Unlike contaminated equipment and debris, spent fuel cannot be shipped off-site for disposal because no permanent repository exists in the United States. Under the Nuclear Waste Policy Act of 1982, the Department of Energy signed contracts with every nuclear utility agreeing to begin accepting spent fuel for disposal by January 31, 1998. The DOE never met that deadline and has partially breached every one of those contracts.

So each decommissioning site keeps its ISFSI, a concrete pad holding dry casks, indefinitely, even after every building is gone and the rest of the property has been released. The NRC authorizes these storage installations under either a general license (available to any power reactor licensee) or a site-specific license, with certificates of compliance valid for up to 40 years.¹⁰

Running an ISFSI at a shut-down reactor costs dramatically more than at an operating plant because the utility must still fund security, radiation monitoring, and regulatory compliance for a site that generates no revenue. Estimates from Idaho National Laboratory put the annual cost at roughly $12 million for a shut-down reactor’s ISFSI, compared to about $1.2 million when the reactor is still running.¹¹ Utilities can seek partial reimbursement from the DOE for these costs under settlement agreements tied to the breach, though payments typically trail actual expenses by years. All reimbursement money comes from the Department of Justice Judgment Fund, not the DOE budget, and the federal government’s total liability has grown into tens of billions of dollars.

Financial Assurance: Who Pays

Federal rules require every reactor owner to set money aside for decommissioning while the plant is still earning revenue, so cleanup costs never fall on taxpayers. Under 10 CFR 50.75, the NRC sets minimum funding levels based on reactor type and thermal power output. In 1986 base dollars, the floor is $105 million for a large pressurized-water reactor and $135 million for a large boiling-water reactor. Those figures are adjusted upward using escalation factors for labor costs, energy costs, and radioactive waste burial charges.¹² After decades of adjustment, the real-dollar amounts needed today are considerably higher.

Licensees can meet the obligation by prepaying into a segregated account before the plant starts operating, by building an external sinking fund over the plant’s operating life, or by combining the two. The money has to sit outside the utility’s control, in accounts separate from corporate assets, so that trouble at the parent company cannot drain the decommissioning account.¹²

Each licensee reports funding status to the NRC at least every two years. Plants within five years of projected shutdown, already closed, or involved in a merger or acquisition report annually. Reports have to include the estimated funding required, current balance, schedule of remaining contributions, and the assumptions behind the investment projections.¹² Shortfalls have to be explained, potentially covered by corporate guarantees or letters of credit.

Trust fund money is generally restricted to radiological decommissioning, meaning the work that reduces residual radioactivity enough to terminate the license. Site restoration to greenfield condition and long-term spent fuel management do not qualify unless the NRC grants a specific exemption. The agency will consider letting a licensee move investment earnings into a separate subaccount for non-radiological costs, but only if the trust balance already exceeds the required radiological estimate by at least $100 million and the utility can show the transfer will not jeopardize its ability to finish the job.¹³

The License Termination Plan and Site Release

The PSDAR starts the project. The License Termination Plan (LTP) finishes it. Every power reactor licensee must submit an LTP for formal NRC approval at least two years before the anticipated license termination date. Unlike the PSDAR, the LTP is approved or denied, and it runs through its own public comment period and public meeting.⁴

The LTP includes a detailed site characterization, identification of any remaining dismantlement work, plans for site remediation, a description of the end use of the site, an updated cost estimate, and detailed plans for the Final Status Survey. If the licensee wants to release the site under restrictions, those go in the LTP too.⁴

Unrestricted Release

Most projects aim for unrestricted release, meaning the site can be used for any purpose without radiological limitations. The Final Status Survey has to show that residual radioactivity above natural background would not deliver more than 25 millirem per year to a person at the site, including exposure through groundwater. Residual contamination also has to be reduced to levels that are as low as reasonably achievable.¹⁴ Once the NRC confirms the standard is met, the license is terminated and the property leaves federal nuclear oversight entirely.

Restricted Release

Sometimes further cleanup would cause more harm than good, for instance if excavating deeply contaminated soil would expose workers to excessive radiation or destroy a wetland. In those cases the NRC can approve license termination with restrictions. Under restricted release, legally enforceable institutional controls have to keep the dose to nearby residents at or below 25 millirem per year. The licensee also has to show that even if those controls failed, the dose would not exceed 100 millirem per year, or 500 millirem in extraordinary cases where further reduction is technically impossible or prohibitively expensive. The utility must fund an independent third party, often a government entity, to maintain the controls and conduct periodic site checks at least every five years.¹⁵

Third-Party Decommissioning Companies

A significant shift over the past decade has been the rise of companies that specialize in buying shut-down reactors and dismantling them. Rather than run a multi-decade teardown as a side operation, a utility transfers the reactor license and the associated decommissioning trust fund to a company whose whole business is rapid dismantlement. These transfers require NRC approval, and the acquiring company has to demonstrate both financial resources and technical capability.

The appeal for utilities is straightforward. Decommissioning is not their core business, and holding a dead asset for decades ties up capital and management attention. For the specialized firms, the economics work because they can deploy experienced crews across multiple sites, negotiate volume-based waste disposal contracts, and complete projects faster than a utility working alone. Faster completion also cuts carrying costs for security, insurance, and spent fuel management. This model has become the dominant approach for recently shut-down plants, and NRC oversight applies the same way whether the original utility or a third-party company holds the license.

1
U.S. Nuclear Regulatory Commission. Locations of Power Reactor Sites Undergoing Decommissioning
2
U.S. Nuclear Regulatory Commission. Backgrounder on Decommissioning Nuclear Power Plants
3
U.S. Nuclear Regulatory Commission. SECY-01-0099 Attachment 3 – Entombment Options for Power Reactors
4
eCFR. 10 CFR 50.82 – Termination of License
5
U.S. Nuclear Regulatory Commission. Regulatory Guide 1.185 – Standard Format and Content for Post-Shutdown Decommissioning Activities Report
6
Nuclear Regulatory Commission. Frequently Asked Questions About Reactor Decommissioning
7
eCFR. 10 CFR Part 20 Subpart C – Occupational Dose Limits
8
U.S. Nuclear Regulatory Commission. 10 CFR 61.55 – Waste Classification
9
Nuclear Regulatory Commission. Locations of Low-Level Waste Disposal Facilities
10
U.S. Nuclear Regulatory Commission. Spent Fuel Storage Licensing
11
Idaho National Laboratory. Spent Fuel Management from Advanced Reactors
12
eCFR. 10 CFR 50.75 – Reporting and Recordkeeping for Decommissioning Planning
13
Federal Register. PSEG Nuclear, LLC; Hope Creek Generating Station, Salem Generating Station, Units 1 and 2, and Peach Bottom Atomic Power Station, Units 2 and 3; Exemption
14
eCFR. 10 CFR Part 20 – Standards for Protection Against Radiation – Section 20.1402
15
eCFR. 10 CFR 20.1403 – Criteria for License Termination Under Restricted Conditions