Audeen W. Fentiman
Matthew E. Jorat
Ronald J. Veley
Commercial low-level radioactive waste is produced, or generated, by five categories of generators: nuclear power plants, industry, medical institutions, research facilities/universities, and some government facilities. The types and volumes of low-level waste vary among these five categories of facilities, as do waste management practices. In addition, because of expected changes in the nation's low-level waste disposal system, the volume of waste being stored at the generation sites is likely to increase. This fact sheet describes the type and amount of low-level waste produced by each category of generator and typical storage practices. It begins with a short summary of changes in plans for disposal and the impact those changes may have on low-level waste storage at the generation sites.
Over the past several years, commercial low-level radioactive waste has been shipped to one of three sites for burial. Those sites are in Barnwell, South Carolina; Beatty, Nevada; and Richland, Washington. Commercial generators usually stored low-level waste at their plants or institutions until enough waste accumulated for a shipment to a disposal site. Then the waste was packaged and shipped by truck to one of the disposal facilities.
As of January 1, 1993, Federal law permitted all three of the existing disposal sites to close. By that time, states and compacts (groups of states organized to manage disposal of their low-level radioactive waste) were supposed to become responsible for disposing of their own low-level waste. On December 31, 1992, the Nevada and Washington sites closed to low-level waste generators from the Midwest Compact (Indiana, Iowa, Minnesota, Missouri, Ohio, Wisconsin). The Barnwell site in South Carolina agreed to continue taking low-level waste from some states, including those in the Midwest Compact, until June 30, 1994. After that time, low-level waste generators in the Midwest Compact may have no place to dispose of their waste until the Compact can open a disposal facility. Each low-level waste generator will be responsible for storing its own low-level waste at the facility where the waste was generated.
Nuclear power plants generate both wet and solid low-level radioactive waste. A significant portion of the wet waste is a result of cleaning reactor cooling water. Some of the more common solid low-level wastes produced at nuclear power plants are protective clothing, shoe covers, paper, construction material, filter materials, and discarded reactor components and equipment. There are currently two nuclear power plants in Ohio and a total of ten in the Midwest Compact.
Some processes and products of industry use radioactive materials. While conducting these processes or manufacturing the products, industry generates low-level radioactive waste. Some of the processes which employ radioactive material are sterilization of food, medical supplies, and cosmetics. Consumer products which have small amounts of radioactive material as components include smoke detectors and some older watches with luminescent dials. Both solid and liquid low-level wastes are generated by industry.
Medical facilities operate nuclear medicine departments which use radioactive material for diagnosing and treating disease. Most of the low-level radioactive waste generated in these departments is in the form of contaminated syringes, glassware, gloves, absorbent pads, and vials containing radioactive drugs.
Some research facilities in this country and around the world use radioactive materials to aid their efforts in developing new products and understanding various chemical, biological, and physical processes. Pharmaceutical development and agricultural studies are examples of uses of radioactive materials. Many universities and colleges also use radioactive materials to aid classroom and laboratory instruction and research in a wide variety of scientific fields. In these universities and other research facilities, low-level radioactive waste is generated in the form of personal protection equipment, glassware, plastic, paper towels, and other potentially contaminated materials.
The government also generates low-level radioactive waste. Most of this waste is produced in veterans' hospitals, by the armed forces, and at numerous federal research and testing facilities. Its form is similar to that of low-level waste from private medical and research institutions. Low-level waste generated by the government's atomic weapons production program is the responsibility of the federal government and is stored and disposed of separately.
The amount of low-level radioactive waste generated can be presented in two ways. One is to give the volume of the waste in cubic feet or cubic meters. The other is to give the activity. Activity is a measure of the rate at which radiation is given off by the radioactive materials in the waste. Activity is measured in curies. The volume and activity of waste shipped to disposal sites is reported annually.
The percentage of low-level radioactive waste volume disposed of by each of the five categories of generator in Ohio in 1991 is illustrated in Figure 1a. The same information for the Midwest Compact is presented in Figure 1b. In Ohio, in 1991, nuclear power plants generated approximately 80 percent of the low-level waste, by volume (see Figure 1a). For the total Midwest Compact region, industry was responsible for the largest percentage (approximately 46 percent) of the low-level waste volume generated (see Figure 1b). (It should be noted that both the total volume and the percentage generated by each category changes from year to year, and no single year is representative of the overall waste generation rates.)
Figure 1. Percent by Volume of Low-Level Radioactive Waste Produced by Generators in Ohio and the Midwest Compact Region in 1991
The percentage of total low-level radioactive waste activity generated by each of the five categories in both Ohio and the Midwest Compact during 1991 is shown in Table 1.
| Table 1. Percentage of Low-Level Radioactive Waste Activity by Generator Category for 1991 | ||
|---|---|---|
| Generator Catagory | % of total activity | |
| Ohio | Midwest Compact | |
| Industry | 0.65 | 24.13 |
| Medical Institutions | 0.09 | 0.08 |
| Nuclear Power Plants | 98.48 | 71.37 |
| Academic Instutions | 0.18 | 0.73 |
| Government | 0.60 | 3.69 |
Between the time when the Barnwell disposal facility closes (currently scheduled for June 30, 1994) and the time the Midwest Compact opens its own disposal facility, generators must store their low-level radioactive waste. Each generator will need to construct a storage facility or designate a building or room(s) equipped with detectors and special handling equipment for storage. These on-site facilities will not be designed to meet the requirements for permanent low-level radioactive waste disposal facilities specified by the Nuclear Regulatory Commission in the Code of Federal Regulations, Title 10, Part 61.
To use on-site storage space as efficiently as possible, low-level radioactive waste generators will attempt to reduce the volume of waste they have generated. The activity of the waste, however, will remain the same. Solid low-level waste generated by industrial sources may be compacted to reduce volume. Incineration (burning) also may be used for volume reduction. Most of the radioactive material remains in the ash or is captured in filters which then must be disposed of as low-level waste. Liquid low-level waste from industry may be stored as is, or solidified in concrete or similar material to confine its movement. Water may also be evaporated from the waste to reduce its volume. Although the waste may be stored in a liquid form at a generator site, liquids are not accepted at a disposal site. The waste, therefore, must be converted to a solid form prior to disposal.
At nuclear power plants, solid low-level radioactive waste will be stored in drums and placed inside a building specifically designed for radioactive waste storage. The solid waste will likely be compacted to reduce its volume. Liquid low-level waste will be placed in large containers lined to avoid corrosion. Liquid waste may be solidified or have water evaporated from it prior to storage.
Some of the radioactive materials used by medical institutions contain low levels of radioactivity and have short half-lives. As a result, hospitals can store these low-level radioactive wastes in special containers until the radioactive materials decay and are no longer considered to be hazardous. This method of storage is called storage for decay. After completion of the necessary storage period, the waste will be disposed of as ordinary trash or classified for low-level waste disposal, depending on its radiation level, which will be lower than when the storage period began.
Similar to industries and nuclear power plants, research institutions are likely to reduce the volume of their waste by compacting or incinerating solid low-level radioactive waste. They will store, solidify, or evaporate water from their liquid waste.
If you would like to read more about generators of low-level radioactive waste and their plans for storing and disposing of that waste, some of the references listed below may be helpful.
Edward L. Gershey, Low-Level Radioactive Waste From Cradle to Grave, Van Nostrand Reinhold, New York, 1990.
Raymond L. Murray, Understanding Radioactive Waste, Battelle Press, Columbus, Ohio, 1989.
Dr. Audeen W. Fentiman is an Assistant Professor in Nuclear Engineering at The Ohio State University. Matthew E. Jorat is a Graduate Research Associate in Nuclear Engineering. Ronald J. Veley is a Graduate Research Associate, Ohio State University Extension.
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Issued in furtherance of Cooperative Extension work, Acts of May 8 and June 30, 1914, in cooperation with the U.S. Department of Agriculture, Keith L. Smith, Director, Ohio State University Extension.
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