Low-Level Radioactive Waste from Decontamination and Decommissioning of Facilities That Use Radioactive Materials

RER-14

Audeen W. Fentiman
P. Andrew Karam
Ronald B. Meyers

Owners of facilities that use radioactive materials must obtain licenses to use those materials. Their licenses require them to decontaminate and decommission their facilities when they are permanently closed. Decommissioning includes removing radioactive contamination from equipment and structures that are to be reused, dismantling equipment and structures that remain contaminated, and disposing of all radioactive materials. Many of the cleaning materials used in decontamination as well as the equipment and structures which remain contaminated are disposed of as low-level radioactive waste.

This fact sheet briefly presents the rules for decommissioning facilities that use radioactive materials, specific options for decommissioning nuclear power plants, and estimates of the amounts of low-level waste generated. The soil and water around some of these facilities may have become contaminated with radioactive materials. Cleaning up the soil and water is generally referred to as environmental restoration. Environmental restoration is a complex topic that needs to be addressed separately and is not included in this fact sheet.

Figure 1. Projected Lifespan of a Nuclear Power Plant That is Dismantled

Rules for Decommissioning

Some decommissioning rules apply to all commercial facilities that use radioactive materials - industries, medical institutions, universities, and non-weapons related government laboratories - as well as to nuclear power plants. Other rules are specific to nuclear power plants and are found primarily in Title 10, Part 50 of the Code of Federal Regulations (10CRF50). Still others are written for facilities, other than nuclear power plants, that use radioactive material, and can be found in sections of Parts 30, 40, 70, and 72 of Title 10 of the Code of Federal Regulations. Each group of rules will be discussed separately in the following sections.

Rules for Decommissioning ALL Facilities That Use Radioactive Materials

For all facilities, the U.S. Nuclear Regulatory Commission (NRC) defines decommissioning to mean reducing radioactive contamination to a level that allows the buildings or property to be used for any purpose. The rule that will establish the level to which contamination must be reduced is not yet final. However, the proposed rule, published in the Federal Register in August of 1994, sets the level at 15 mrem/year distinguishable from background. (The average background radiation in the United States is 360 mrem/year and is discussed in fact sheet RER-22 of this series.) Owners of a facility are required to further reduce the level of contamination to be "As Low As Reasonably Achievable" (ALARA). If contamination cannot be reduced to the required level (15mrem/year), or if the cost to achieve that level is prohibitive, the NRC can allow, on a case-by-case basis, restricted release. Restricted release means that the property can be used only for certain, specified purposes.

All licensed facilities must also provide financial assurance. That is, they must set aside funds to pay for decontamination and decommissioning. The regulations specify ways that the funds can be set aside.

Rules Specific to Decommissioning Nuclear Power Plants

For nuclear power plants, a preliminary decommissioning plan must be submitted to the Nuclear Regulatory Commission (NRC) five years before the projected end of operations at the plant. The plan is to include a cost estimate and a discussion of the major technical factors that will affect decommissioning. The plan must show how decommissioning will be completed within 60 years of the end of operations, or explain why more time is needed to protect public health and safety. The NRC must approve the plan and may hold public hearings on it. Also, five years before the end of operations, the utility is required to submit a plan for managing the irradiated fuel at the plant. Irradiated or spent fuel is generally stored at nuclear power plants and must be removed from the site as part of the decommissioning process.

Nuclear Power Plant Decommissioning Options

The NRC recognizes three decommissioning options for nuclear power plants: DECON, SAFSTOR, and ENTOMB. Most utilities have not yet selected a decommissioning method.

If the DECON option is selected, irradiated fuel is removed, and the buildings are decontaminated or dismantled and disposed of. Contamination at the site is reduced to, or below, the required level as quickly as possible. Some of the dismantling may be done using remote controlled equipment to reduce worker exposure.

Under the SAFSTOR option, irradiated fuel is removed, some decontamination is done, and the facility is closed up, or put in "Safe Storage", for several years while most of the remaining radioactive materials decay. Then, when the radiation levels are lower, workers finish cleaning up or dismantling the facility before the property is released.

If the ENTOMB option is chosen, the utility removes all irradiated fuel and contaminated liquids and then entombs the plant in concrete or other acceptable material. The tomb is monitored and maintained until the radioactive material in it has decayed to a level which allows the property to be released.

Note that at the present time, the United States has no central disposal facility for irradiated fuel. Since removing irradiated fuel from the nuclear power plant site is an important early step in decommissioning, lack of such a disposal site may affect decommissioning schedules.

Rules Specific to Decommissioning Facilities Other Than Nuclear Power Plants

Facilities other than nuclear power plants need to notify the Nuclear Regulatory Commission when they are ready to begin decommissioning. The notice must be sent within 60 days of the time the facility's license expires, or the time the owner decides to stop operating. If the license requires a decommissioning plan, that plan must be submitted to the NRC for approval within 12 months of the notice. If the license does not require a decommissioning plan, decommissioning must have begun by the time of the notice. Decommissioning is to be completed in 24 months.

In Agreement States, where state agencies have responsibility for regulating some facilities using radioactive materials, different rules may be developed. However, the state's rules must be at least as stringent as the NRC's rules. (Note that even in Agreement States, the NRC retains responsibility for regulating nuclear power plants.)

Low-Level Radioactive Waste from Decommissioning

The volume of low-level radioactive waste resulting from decommissioning of nuclear facilities other than nuclear power plants varies greatly depending on the type and size of the facility, the work done there, the type of contamination present, and the waste treatment and volume reduction procedures used. The volume could range from nearly zero to tens of thousands of cubic feet.

The volume of low-level radioactive waste from the decommissioning of a nuclear power plant can also vary greatly depending on the type and size of the plant, the length of time it is operated, the decommissioning option chosen, and the waste treatment and volume reduction procedures used. The estimated volume of low-level radioactive waste from the decommissioning of a nuclear power plant in the Midwest Compact region ranges from about 100,000 to 400,000 cubic feet.

Eleven nuclear power reactors are located in the member states of the Midwest Compact. The names of the power plants, their locations, sizes, and dates they began operating are presented in Table 1. The initial operating license for a nuclear power plant is usually 40 years, although some do not operate that long and others may operate longer.

Table 1: Nuclear Power Plants in the Midwest Compact Region
Plant Name	Location	Size (MWe)	Began Operation
Duane Arnold	Palo, Iowa	515	2/75
Monticello	Monticello, Minnesota	536	6/71
Prairie Island 1	Red Wing, Minnesota	503	12/73
Prairie Island 2	Red Wing, Minnesota	500	12/74
Callaway	Fulton, Missouri	1125	4/85
Davis Besse	Oak Harbor, Ohio	874	7/78
Perry 1	North Perry, Ohio	1166	11/87
Point Beach 1	Two Rivers, Wisconsin	485	12/70
Point Beach 2	Two Rivers, Wisconsin	485	10/72
Kenaunee	Carlton, Wisconsin	535	6/74
LaCrosse	Genoa, Wisconsin	50	7/76*
Closed 4/87

For More Information

If you would like to read more about decontamination and decommissioning of nuclear facilities, the references listed below may be helpful.

Code of Federal Regulations, Title 10, Part 50 "Domestisc Licensing of Production and Utilization Facilities".

Federal Register, Volume 59, August 22, 1994, Page 43,200

Office of Technology Assessment, "Aging Nuclear Power Plants: Managing Plant Life and Decommissioning", September 1993.

U.S. Nuclear Regulatory Commission, NUREG-1350, Volume 5, March 1993.

Other fact sheets in this series? RER-22 "What Are the Sources of Ionizing Radiation?"

Author Notes:

Dr. Audeen W. Fentiman is an Associate Professor in Nuclear Engineering at The Ohio State University. P. Andrew Karam is a Certified Health Physicist and a Graduate Research Associate in Geology. Ronald B. Meyers is a Graduate Research Associate, Ohio State University Extension.