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Fact Sheet on Decommissioning Nuclear Power Plants

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Background

When a power company decides to close its 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 Nuclear Regulatory Commission has strict rules governing nuclear power plant decommissioning, involving cleanup of radioactively contaminated plant systems and structures and removal of the radioactive fuel. These requirements protect workers and the public during the entire decommissioning process and the public after the license is terminated.

Discussion

Licensees may choose from three alternative decommissioning strategies: DECON, SAFSTOR, or ENTOMB.

• Under DECON (immediate dismantlement), soon after the nuclear facility closes, 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, often considered "delayed DECON," a nuclear facility is maintained and monitored in a condition that allows the radioactivity to decay; afterwards, it is dismantled.

• Under ENTOMB, radioactive contaminants are permanently encased onsite in a structurally sound material such as concrete and appropriately maintained and monitored until the radioactivity decays to a level permitting restricted release of the property.

To be acceptable, decommissioning must be completed within 60 years of the plant ceasing operations. A time beyond that would be considered only when necessary to protect public health and safety in accordance with NRC regulations.

Regulations

The requirements for decommissioning a nuclear power plant are set out in NRC regulations (Title 10 of the Code of Federal Regulations, part 20 subpart E, and parts 50.75, 50.82, 51.53, and 51.95). 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 allows no major decommissioning activities to be undertaken until after certain information has been provided to the NRC and the public.

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 that there will be sufficient money to pay for the ultimate decommissioning of the facility. Licensees must update the NRC on the status of these mechanisms every two years (annually within five years of the planned end of plant operations). This requirement provides the public reasonable assurance that funds will be available when needed to clean up a plant site and avoid costly legacy sites that must be cleaned up at taxpayer expense.

Public Involvement

Several opportunities are provided for public involvement during the decommissioning process.  A public meeting is held in the vicinity of the facility after submittal of a post-shutdown decommissioning activities report (PSDAR) to the NRC.  Another public meeting is held when NRC receives the license termination plan (LTP).  An opportunity for a public hearing is provided prior to issuance of a license amendment approving the LTP or any other license amendment request.   In addition, when NRC holds a meeting with the licensee, members of the public are allowed to observe the meeting (except when the discussion involves proprietary, sensitive, safeguards, or classified information).

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 that meets regulatory requirements while maintaining a small parcel under license for storing the spent fuel. These stand-alone facilities, called “independent spent fuel storage installations” (ISFSIs), remain under license and NRC regulation, and the licensees are responsible for security and for maintaining insurance and funding for eventual decommissioning.

As more facilities complete decommissioning, the NRC is implementing “lessons learned” in order to improve the program and focus on the prevention of future legacy sites. Applications for new reactors must now describe how design and operations will minimize contamination during the plant’s operating life and facilitate eventual decommissioning. The agency is developing new regulations that will require plant operators to be more vigilant in preventing contamination during operations, and cleaning up and monitoring any contamination that does occur. 

Phases of Decommissioning

The requirements for power reactor decommissioning activities may be divided into three phases: (1) initial activities; (2) major decommissioning and storage activities; and (3) license termination activities.

(1) Initial Activities

When a nuclear power plant licensee shuts down the 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 the reactor vessel. This eliminates the obligation to adhere to certain requirements needed only during reactor operation.

Within two years after submitting the certification of permanent closure, the licensee must submit a post-shutdown decommissioning activities report (PSDAR) to the NRC. This report provides a description of the planned decommissioning activities, along with a schedule for accomplishing them, and an estimate of the expected costs. The PSDAR must discuss the reasons for concluding that environmental impacts associated with the site-specific decommissioning activities have already been addressed in previous environmental analyses. Otherwise, the licensee must request a license amendment for approval of the activities and submit to the NRC a report on the additional impacts of decommissioning on the environment.

After receiving a PSDAR, the NRC publishes a notice of receipt in the Federal Register, makes the report available for public review and comment, and holds 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 PSDAR, the owner can begin major decommissioning activities without specific NRC approval. These activities could 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 not:

• prevent release of the site for possible unrestricted use,
• result in there being no 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 funds set aside for decommissioning planning. An additional 20 percent can be used 90 days after submittal of the PSDAR. The remaining decommissioning trust funds are then available when the owner submits a detailed site-specific cost estimate to the NRC.

(3) License Termination Activities

The owner is required to submit a LTP within two years of the expected license termination. The plan addresses each of the following: site characterization, identification of remaining site dismantlement activities, plans for site remediation, detailed plans for final radiation surveys for release of the site, method for demonstrating compliance with the radiological criteria for license termination, updated site-specific estimates of remaining decommissioning costs, and a supplement to the environmental report that describes any new information or significant environmental changes associated with the owner's proposed termination activities. Most plans envision releasing the site to the public for unrestricted use, meaning any residual radiation would be below 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, documentation on public consultation, institutional controls, and financial assurance needed to comply with the requirements for license termination for restricted release.

The 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.

The NRC uses a standard review plan (NUREG-1700, "Standard Review Plan for Evaluating Nuclear Power Reactor License Termination Plans)" to ensure high quality and uniformity of LTP reviews. The standard review plan is available to the public so that NRC's review process is understood clearly.

If the remaining dismantlement has been performed in accordance with the approved LTP and the termination survey demonstrates that the facility and site are suitable for release, the NRC issues a letter terminating the operating license.

Permanently Shutdown Nuclear Power Plants

There are currently 13 nuclear power plant units that have permanently shut down and are in some phase of the decommissioning process. These are:

•        Dresden Nuclear Power Station, Unit 1
•        GE VBWR (Vallecitos)
•        Humboldt Bay Power Plant, Unit 3
•        Fermi 1 Power Plant;
•        Indian Point Unit 1
•        LaCrosse Boiling Water Reactor
•        Millstone Nuclear Power Station, Unit 1
•        N.S. Savannah
•        Peach Bottom Unit 1
•        Rancho Seco Nuclear Generating Station
•        San Onofre Nuclear Generating Station, Unit 1
•        Three Mile Island Nuclear Station, Unit 2
•        Zion Nuclear Power Station, Units 1 and 2

These are described in greater detail in the material that follows.

Ten nuclear power plants have completed the decommissioning process and have had their operating license terminated.  These are:

•        Big Rock Point
•        Fort St. Vrain Nuclear Generating Station
•        Haddam Neck - Connecticut Yankee
•        Shoreham Nuclear Power Station
•        CTVR (Pressurized Tube, Heavy Water); and
•        Pathfinder (Superheat BWR).
•        Maine Yankee Atomic Power Station
•        Saxton
•        Trojan
•        Yankee Rowe Nuclear Station

January 2008

Figure 1 - Demolition of a Reactor Containment Building

Figure 2 - Removal of Contamination on Nuclear Plant Wall

Figure 3 - A Steam Generator is Removed from a Reactor Building

Power Reactors in the Decommissioning Process

Current updates of all power reactor sites undergoing decommissioning are available at: http://www.nrc.gov/info-finder/decommissioning/power-reactor/.

DRESDEN - UNIT 1

The plant shut down in October 1978 and is currently in SAFSTOR. The decommissioning plan (DP) was approved in September 1993. No significant dismantlement activities are underway.  Isolation of Unit 1 from Units 2 and 3 is complete. All spent fuel from Unit 1 that was previously stored in the Unit 1 spent fuel pool (SFP), the Unit 1 fuel transfer pool, and the Unit 2 SFP has now been transferred to the on-site independent spent fuel storage installation (ISFSI). Currently, 108 spent fuel assemblies and one fuel rod basket from Unit 1 are stored in the Dresden Unit 3 SFP.

The licensee plans to have decontamination and dismantlement of Unit 1 take place from 2029 through 2031 when Units 2 and 3 are nearing the end of their life. Following decontamination and dismantlement of Units 2 and 3, site restoration will be conducted in 2035 and 2036, with final site surveys to be performed in late 2036.

GE- VBWR (VALLECITOS BOILING WATER REACTOR)

The plant was shut down in December 1963 and issued a possession-only license in 1965. The plant is in SAFSTOR and plans to remain in SAFSTOR until ongoing nuclear activities at the site are terminated and the entire site can be decommissioned. All nuclear fuel has been removed from the site.

HUMBOLDT BAY

The plant was shut down in July 1976 and is currently in DECON with minor decommissioning activities ongoing. A DP was approved in July 1988 – currently called a Defueled Safety Analysis Report, it is updated every two years. A post-shutdown activities report (PSDAR) was issued by the licensee in February 1998. Asbestos has been removed, and current work includes radiological characterization of systems and structures. Future work includes: reactor and internals activation analysis; low-level waste management plan development; development of a work, cost, and scheduling process; and development of a facilities and staffing plan.

The licensee has been constructing an ISFSI during 2007 with fuel loading expected in 2008. The licensee will also be constructing two new fossil-fuel units in 2008 and 2009 to replace Humboldt Bay Units 1 and 2. Following construction of the new units, the old fossil-fuel Units 1 and 2 will be decommissioned in 2009 and 2010. During this period only incremental decommissioning of Unit 3 will take place. As the decommissioning of the fossil units is completed, full decommissioning of Unit 3 will begin. The license termination plan (LTP) will probably be submitted in 2010 or 2011, with license termination in 2012 or 2013.

FERMI - UNIT 1

The plant was shut down in September 1972 and is currently in SAFSTOR/DECON. The spent fuel has been removed from the site. The licensee is performing occupational safety enhancement activities, concentrating in non-radioactive areas, such as asbestos removal. Bulk sodium has been removed from the site. The PSDAR public meeting was held on April 22, 1998. The owner plans to submit its LTP in 2009.

INDIAN POINT - UNIT 1

The plant was shut down in October 1974. Currently, there is no significant dismantlement underway.  The owner plans to decommission Unit 1 concurrently with Unit 2, which remains in operation. The PSDAR public meeting was held on Jan. 20, 1999.

LA CROSSE

The plant was shut down on April 30, 1987. The SAFSTOR DP was approved Aug. 7, 1991. The DP is considered the PSDAR. The PSDAR public meeting was held on May 13, 1998. The licensee has been conducting dismantlement and decommissioning activities and is currently developing plans for an ISFSI. 

MILLSTONE - UNIT 1

Unit 1 was shut down Nov. 4, 1995, and transfer of the spent fuel to the SFP was completed Nov. 19, 1995. On July 21, 1998, the licensee certified to the NRC that, as of July 17, 1998, Millstone Unit 1 had permanently ceased operations and that fuel had been permanently removed from the reactor vessel. The owner's current plan is to leave the plant in SAFSTOR until the Unit 2 license expires, which is currently scheduled for July 31, 2015. The owner submitted its required PSDAR on June 14, 1999, and has chosen a combination of the DECON and SAFSTOR options.

Safety-related structures, systems, and components (SSCs) remaining at Millstone Unit 1 are associated with the SFP “island” where the Millstone Unit 1 spent fuel is stored. Other than non-essential systems supporting the balance of plant facilities, the remaining plant equipment has been disabled and abandoned in place or removed from the unit and can no longer be used for power generation.

N.S.  SAVANNAH

The ship was removed from service in 1970 and its fuel removed in October 1971. The reactor is currently in SAFSTOR. The Nuclear Ship (NS) Savannah has been removed from the Maritime Administration Reserve Fleet in the James River, Va. On May 31, 2007, the NS Savannah was relocated from Newport News, Va. to Norfolk, Va. 

PEACH BOTTOM - UNIT 1

The plant was shut down in October 1974 and is in SAFSTOR with no significant dismantlement underway. Active decommissioning of Unit 1 is not expected until 2034, when Units 2 and 3 are scheduled to shut down. The PSDAR public meeting was held on June 29, 1998. The spent fuel has been removed from the site.

RANCHO SECO

The plant was shut down in June 1989. The SAFSTOR DP was approved in March 1995. On Jan. 9, 1997, the Sacramento Municipal Utility District (SMUD) Board of Directors approved an "incremental decommissioning" project for Rancho Seco which began in early 1997. On July 1, 1999, the SMUD Board of Directors voted to continue the decommissioning process at Rancho Seco until termination of the 10 CFR 50 license.  However, based upon the lack of suitable waste disposal options, the licensee intends to store Class B and C radioactive waste in an Interim Onsite Storage Building until a suitable disposal facility becomes available, which will necessitate retaining the Part 50 license.

On Oct. 4, 1991, the owner submitted a site-specific Part 72 ISFSI application using the VECTRA NUHOMS-MP187 dual-purpose cask design. The license was granted on June 30, 2000. On Aug. 21, 2002, Rancho Seco completed placing all 493 spent fuel assemblies in dry storage at the onsite ISFSI.

The licensee has completed dismantlement of the secondary side equipment in the turbine building. Wastes generated during decommissioning are being shipped to Envirocare in Utah for disposal. The licensee is now dismantling equipment in the auxiliary and reactor buildings.

SAN ONOFRE - UNIT 1

Southern California Edison (SCE) shut down the reactor in November 1992 and placed it in SAFSTOR until the planned shutdown of Units 2 and 3 in 2022. In 1998, following a change in NRC decommissioning regulations, SCE submitted a PSDAR for San Onofre Unit 1 to commence DECON in 2000. Since that time, it has been actively decommissioning the facility. SCE is removing all structures down to the -8' building level. In late 2007, the licensee began construction of Phase 2 of the ISFSI on the former containment vessel site. SCE plans to apply for a partial site release of the off-shore cooling pipes by the end of 2007. 

THREE MILE ISLAND - UNIT 2

The operating reactor accident occurred in March 1979. Plant de-fueling was completed in April 1990.  Post De-fueling Monitored Storage was approved in 1993. There is no significant dismantlement underway. The plant shares equipment with the other operating unit, which was sold to Amergen in 1999. GPU Nuclear retains the license for Three Mile Island Unit 2 and contracts to Amergen for maintenance and surveillance activities. Both units are currently expected to be decommissioned together in 2014. The U.S. Department of Energy has taken title and possession of the spent fuel (except for some debris in the primary systems), which is currently in storage at the Idaho National Laboratory.

ZION - UNITS 1 AND 2

Zion Units 1 and 2 were permanently shut down on Feb.13, 1998. The fuel was transferred to the SFP, and the owner submitted the certification of fuel transfer on March 9, 1998. The licensee is maintaining the turbine-generators as synchronous condensers to support grid stability and has isolated the SFP within a fuel building "nuclear island." The plant has been placed in SAFSTOR, where it will remain until about 2013 when the decommissioning trust fund will be sufficient to conduct DECON activities. The owner submitted the PSDAR, site-specific cost estimate, and fuel management plan on Feb. 14, 2000.

Preparations for decontamination and dismantlement are scheduled to commence at the original license expiration date for Zion Nuclear Power Station Unit 2 on Nov. 14, 2013. Final site survey and license termination is currently planned for 2025 - 2026.                                    

Decommissioning Status for Shut Down Power Reactors (As of Jan. 2008)

* Post-defueling monitored storage (PDMS).

Note: An independent spent fuel storage installation (ISFSI) is a stand-alone facility within the plant boundary constructed for the interim storage of spent nuclear fuel.