Dry Cask sa

stored and m

until dispos

AFTER CLEANUP

Decommissioning 

Nuclear Power Plants

Shutdown

Activities

Decommissioning 

Plans to the NRC

Fuel

Removed

BEFORE CLEANUP

Shutdown

Activities

Decommissioning 

Plans to the NRC

Fuel

Removed

BEFORE CLEANUP

DURING CLEANUP

SAFSTOR

DECON

ACTIVITIES 

REPORT

NRC INSPECTIONS

LICENSE 

TERMINATION 

PLAN

DURING CLEANUP

The facility is shut 

down and maintained 

for several years 

while residual 

radioactivity decays. 

This makes ultimate 

decontamination 

easier. Contaminated structures, 

systems and components 

are removed from the site 

and disposed of as low-level 

radioactive waste. The 

facility is decontaminated to 

a level that permits the site 

to be released for 

unrestricted use. DECON 

can occur soon after the 

plant ceases operation or 

after a period of SAFSTOR.

Contaminated parts of a 

facility are encased in a 

durable material, such as 

concrete, and maintained 

until radioactivity decays 

to a safe. This method has 

never been used by an 

NRC-licensed nuclear 

plant.

SAFSTOR

ENTOMB

DECON

NUREG/BR–0521, Rev. 1

June 2017

DECOMMISSIONING FUNDS

Before a nuclear power plant begins operations, 

the licensee must establish or obtain a financial 

mechanism—such as a trust fund or a guarantee 

from its parent company—to ensure there will 

be sufficient money to pay for the ultimate 

decommissioning of the facility. 

Each nuclear power plant licensee must report 

to the NRC every two years the status of its 

decommissioning funding for each reactor or share 

of a reactor that it owns. The report must estimate 

the minimum amount needed for decommissioning 

by using the formulas found in NRC regulations. 

Licensees may alternatively determine a sitespecific funding estimate, provided that amount is 

greater than the generic decommissioning estimate. 

Although there are many factors that affect reactor 

decommissioning costs, generally they range from 

$300 million to $400 million. The staff performs 

an independent analysis of each of these reports 

to determine whether licensees are providing 

reasonable “decommissioning funding assurance” 

for radiological decommissioning of the reactor at 

the permanent termination of operation.

These reports are required annually during 

decommissioning so the NRC can ensure the funds 

are being used appropriately.

DECOMMISSIONING PROGRAM 

RESOURCES

Decommissioning Fund

10CFR 50.75–Reporting and recordkeeping for 

decommissioning planning

http://www.nrc.gov/reading-rm/doc-collections/

cfr/part050/part050-0075.html

License Termination Activities

NUREG–1700, Standard Review Plan for Evaluating 

Nuclear Power Reactor License Termination Plans

http://www.nrc.gov/reading-rm/doc-collections/

nuregs/staff/sr1700/ 

NRC Q&A Series: Five Minutes with an NRC Expert 

on Decommissioning

https://www.youtube.com/watch?v=GifRku-N7_Q 

Dry Cask 

Storage
IMPROVING THE 

DECOMMISSIONING PROGRAM

Several nuclear power plants completed 

decommissioning in the 1990s without a viable 

option for disposing of their spent nuclear 

fuel because the Federal Government did not 

construct a geologic repository as planned. 

Accordingly, the NRC implemented regulations 

allowing licensees to sell off part of their land 

once it meets NRC release criteria, while 

maintaining a small parcel under license for 

storing the spent fuel. These stand-alone 

facilities, called “independent spent fuel storage 

installations,” remain under license and NRC 

regulation. Licensees are responsible for security 

and for maintaining insurance and funding for 

eventual decommissioning.

The NRC has taken several steps to improve the 

decommissioning process. New reactors must 

be designed to minimize potential contamination. 

Plant operators must take steps to prevent 

contamination during operations, and to clean up 

and monitor any contamination that does occur. 

The NRC is currently developing regulations to 

make a plant’s transition from operating status 

to decommissioning more efficient by modifying 

certain licensing requirements for reactors after 

they permanently cease operations.

DECOMMISSIONING STRATEGIES

Decommissioning involves active cleanup and 

decontamination, called DECON for short, or a 

combination of DECON and deferred dismantling, or 

SAFSTOR.

Under DECON, equipment, structures and 

portions of the facility containing radioactive 

contaminants are removed or decontaminated to a level 

that permits release of the property and termination of 

the NRC license.

Under SAFSTOR, a nuclear power plant is 

maintained and monitored in a condition that 

allows the radioactivity to decay; afterwards, the plant 

shifts to DECON as the facility is dismantled and the 

property decontaminated. 

A licensee may combine these two strategies, 

leaving parts of the facility in SAFSTOR while actively 

dismantling and decontaminating other parts of the 

facility. The decision may be based on factors other 

than radioactive decay, such as the availability of waste 

disposal sites.

A third strategy, known as ENTOMB, would encase 

contaminated facilities in concrete. No U.S. commercial 

nuclear power plant has chosen this option.

Once DECON is complete and the site meets the NRC’s 

cleanup standards, the 

NRC will terminate the 

license and release the 

property for unrestricted 

use. A portion of the 

site may remain under 

NRC license to store the 

spent fuel. The licensee 

is responsible for 

maintaining and protecting 

the spent fuel storage 

facility.

Decommissioning must 

be completed within 60 

years of the plant ceasing 

operations.

DECOMMISSIONING

OVERVIEW

SHUTDOWN

FUEL 

TRANSFER TO

DRY CASK

DECONTAMINATION

SAFSTOR

DISMANTLING

LAND 

REUSE

OPERATION

........................................................................................ up to 60 years

DECOMMISSIONING LAND REUSE

0 — 2 years

Licensee Submits

Decommissioning

Plans.

DECOMMISSIONING TIMELINE

D

S

1. Title 10 CFR Part 20, Subpart E, and 10 CFR 50.75, 50.82, 51.53, and 51.95 Images of decommission job at San Onofre Unit 1 in California.

When a power company decides to close a 

nuclear power plant permanently, the facility 

must be decommissioned by safely removing it 

from service and reducing residual radioactivity 

to a level that permits release of the property 

and termination of the operating license. The 

U.S. Nuclear Regulatory Commission’s rules 

govern nuclear power plant decommissioning 

to ensure cleanup of radioactively contaminated 

plant systems and structures and removal of the 

radioactive fuel. These requirements protect 

workers, the public and the environment during 

the entire decommissioning process and after 

the license is terminated. 

REGULATIONS

The requirements for decommissioning a 

nuclear power plant are set out in several 

NRC regulations.1 In August 1996, a revised 

rule went into effect that redefined the 

decommissioning process and required owners 

to provide the NRC with early notification of 

planned decommissioning activities. The rule 

restricts licensees from undertaking any major 

decommissioning activities to be undertaken 

until after certain information has been provided 

to the NRC and the public. 
1. Initial Activities

When a nuclear power plant licensee shuts down 

a plant permanently, it must submit a written 

certification of permanent cessation of operations 

to the NRC within 30 days. When radioactive nuclear 

fuel is permanently removed from the reactor vessel, 

the owner must submit another written certification 

to the NRC, surrendering its authority to operate 

the reactor or load fuel into a reactor vessel. This 

eliminates the obligation to adhere to certain 

requirements needed only during reactor operation.

Within 2 years after submitting the certification of 

permanent closure, the licensee must submit a 

post-shutdown decommissioning activities report 

to the NRC. This report provides a description of the 

planned decommissioning activities, a schedule for 

accomplishing them, and an estimate of the expected 

costs. The report must discuss the reasons for 

concluding that environmental impacts associated 

with the site-specific decommissioning activities have 

already been addressed in previous environmental 

analyses. 

After receiving the report, the NRC will publish a 

notice of receipt in the Federal Register, make the 

report available for public review and comment, 

and hold a public meeting in the vicinity of the plant 

to discuss the licensee’s intentions.

2. Major Decommissioning Activities

Ninety days after the NRC receives the planning 

report, the owner can begin major decommissioning 

activities without specific NRC approval. These 

include permanent removal of such major 

components as the reactor vessel, steam generators, 

large piping systems, pumps, and valves.

However, decommissioning activities conducted 

without specific prior NRC approval must 

ensure that the release of the site will allow for 

possible unrestricted use, result in reasonable 

assurance that adequate funds will be available 

for decommissioning, or 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, which would provide an 

opportunity for a public hearing.

Initially, the owner can use up to 3 percent of its 

set-aside funds for decommissioning planning. 

The remainder will become available 90 days after 

submittal of the planning report unless the NRC 

staff has raised objections.

3. License Termination Activities 

The owner is required to submit a license 

termination plan within 2 years of the expected 

license termination. The plan addresses each of 

the following: site characterization, remaining site 

dismantlement activities, plans for site remediation, 

detailed plans for final radiation surveys for 

release of the site, updated estimates of remaining 

decommissioning costs, and a supplement to the 

environmental report describing any new information 

or significant environmental changes associated with 

the final cleanup. Most plans envision releasing the 

site to the public for unrestricted use, meaning any 

residual radiation would be below the NRC’s limits 

of 25 millirem annual exposure and there would be 

no further regulatory controls by the NRC. Any plan 

proposing release of a site for restricted use must 

describe the site’s end use, public consultation, 

institutional controls, and financial assurance 

needed to comply with the requirements for license 

termination for restricted release. 

The license termination report (LTP) requires NRC 

approval of a license amendment. Before approval 

can be given, an opportunity for hearing is published 

and a public meeting is held near the plant site.

If the remaining dismantlement has been performed 

in accordance with the approved LTP and the NRC’s 

final survey demonstrates that the facility and site 

are suitable for release, the NRC will issue a letter 

terminating the operating license.

Shutdown

Activities

Decommissioning 

Plans to the NRC

Fuel

Removed

BEFORE CLEANUP

ACTIVITIES 

REPORT

NRC INSPECTIONS

LICENSE 

TERMINATION 

PLAN

DURING CLEANUP

SAFSTOR

ENTOMB

DECON

NRC

Conducts

Survey

License

Terminated

Site released for

public or other use.

Dry Cask safely

stored and monitored

until disposal.

AFTER CLEANUP

PHASES OF DECOMMISSIONING

The requirements for power reactor decommissioning activities may be divided into three phases: 
The public has several opportunities to participate in the decommissioning 

process. A public meeting is held in the vicinity of the facility after submittal 

of a post-shutdown decommissioning activities report to the NRC. Another 

public meeting is held when the NRC receives the license termination plan. 

An opportunity for a public hearing is provided before the NRC issues a 

license amendment approving the plan or any other license amendment 

request. In addition, when the NRC holds a meeting with the licensee, 

members of the public may observe the meeting (except when the discussion 

involves proprietary, sensitive, safeguards, or classified information). 

PUBLIC INVOLVEMENT

FLORIDA

Crystal River 3

MICHIGAN

Fermi 1 

PENNSYLVANIA

Saxton 

CALIFORNIA

GE EVESR

S

S S S

S S

SAFSTOR

S

S S

S

S

S

S

S

S

D

D

D

S

DECON

I ISFSI (Independent Spent Fuel Storage Installation only)

License Terminated

Decommissioning Completed

S

D

D

San Onofre 1

San Onofre 2 & 3

Vallecitos

EVESR & VBWR

Kewaunee

Rancho Seco

Humboldt Bay 3

Trojan

Big Rock 

Point Maine 

Yankee

Peach 

Bottom 1

Shoreham

Haddam 

Neck

Millstone 1

N.S. Savannah

(Baltimore Harbor)

Vermont Yankee

Yankee

Rowe

Indian Point 1

Crystal River 3

Fort St. Vrain

(DOE License)

Pathfinder

Fort Calhoun

LaCrosse

Zion 1 & 2

Dresden 1

Fermi 1

Three Mile 

Island 2

Saxton

I

I

I

I

I

I

I S

Notes: GE Bonus, Hallam, and Piqua decommissioned reactor sites are part of the DOE nuclear legacy. For more information, visit DOE’s 

Office of Legacy Management LM Sites Web page at https://www.energy.gov/lm/sites/lm-sites. CVTR, Elk River, and Shippingport 

decommissioned reactor sites were either decommissioned before the formation of the NRC or were not licensed by the NRC. Licensees 

have announced intention to permanently cease operations for the following: – Palisades (2018), Pilgrim (2018) Three Mile Island (2019), 

Indian Point (2020 and 2021), Oyster Creek (2019) and Diablo Canyon (2025). NRC-abbreviated reactor names are listed. For the most 

recent information, go to the Dataset Index Web page https://www.nrc.gov/reading-rm/doc-collections/datasets/