Low level waste
Encyclopedia
Spent nuclear fuel
Spent nuclear fuel, occasionally called used nuclear fuel, is nuclear fuel that has been irradiated in a nuclear reactor...
(SNF), transuranic waste
Transuranic waste
Transuranic waste is, as stated by U.S. regulations and independent of state or origin, waste which has been contaminated with alpha emitting transuranic radionuclides possessing half-lives greater than 20 years and in concentrations greater than 100 nCi/g .Elements having atomic numbers greater...
(TRU), or certain byproduct materials known as 11e(2) wastes, such as uranium mill tailings. In essence, it is a definition by exclusion, and LLW is that category of radioactive wastes that do not fit into the other categories. If LLW is mixed with hazardous wastes, then it has a special status as Mixed Low-Level Waste (MLLW) and must satisfy treatment, storage, and disposal regulations both as LLW and as hazardous waste.
While the bulk of LLW is not highly radioactive, the definition of LLW does not include references to its activity, and some LLW may be quite radioactive, as in the case of radioactive sources used in industry and medicine.
The definition of low level waste is set by the nuclear regulators of individual countries, though the IAEA provides recommendations. Some countries, such as France, specify categories for long-lived low (and intermediate) level waste.
Disposal
Depending on who "owns" the waste, its handling and disposal is regulated differently. All nuclear facilities, whether they are a utility or a disposal site, have to comply with NRC regulations. The three low-level waste facilities in the U.S. are Barnwell, South CarolinaBarnwell, South Carolina
Barnwell is a city in Barnwell County, South Carolina, United States, located along U.S. Route 278. The population was 5,035 at the 2000 census...
, Richland, Washington
Richland, Washington
Richland is a city in Benton County in the southeastern part of the U.S. state of Washington, at the confluence of the Yakima and the Columbia Rivers. As of the 2010 census, the city population was 48,058. April 1, 2011 estimates from the Washington State Office of Financial Management put the...
, and Clive, Utah. The Barnwell and the Clive locations are operated by EnergySolutions, whereas the Richland location is operated by U.S. Ecology. Barnwell and Richland accept Classes A through C of low-level waste, whereas Clive only accepts Class A LLW. The DOE has dozens of LLW sites under management. The largest of these exist at DOE Reservations around the country (e.g. the Hanford Reservation
Hanford Site
The Hanford Site is a mostly decommissioned nuclear production complex on the Columbia River in the U.S. state of Washington, operated by the United States federal government. The site has been known by many names, including Hanford Works, Hanford Engineer Works or HEW, Hanford Nuclear Reservation...
, Savannah River Site
Savannah River Site
The Savannah River Site is a nuclear reservation in the United States in the state of South Carolina, located on land in Aiken, Allendale and Barnwell Counties adjacent to the Savannah River, southeast of Augusta, Georgia. The site was built during the 1950s to refine nuclear materials for...
, Nevada Test Site
Nevada Test Site
The Nevada National Security Site , previously the Nevada Test Site , is a United States Department of Energy reservation located in southeastern Nye County, Nevada, about northwest of the city of Las Vegas...
, Los Alamos National Laboratory
Los Alamos National Laboratory
Los Alamos National Laboratory is a United States Department of Energy national laboratory, managed and operated by Los Alamos National Security , located in Los Alamos, New Mexico...
, Oak Ridge National Laboratory
Oak Ridge National Laboratory
Oak Ridge National Laboratory is a multiprogram science and technology national laboratory managed for the United States Department of Energy by UT-Battelle. ORNL is the DOE's largest science and energy laboratory. ORNL is located in Oak Ridge, Tennessee, near Knoxville...
, Idaho National Laboratory
Idaho National Laboratory
Idaho National Laboratory is an complex located in the high desert of eastern Idaho, between the town of Arco to the west and the cities of Idaho Falls and Blackfoot to the east. It lies within Butte, Bingham, Bonneville and Jefferson counties...
, to name the most significant).
Classes of wastes are detailed in 10 C.F.R. § 61.55 Waste Classification enforced by the Nuclear Regulatory Commission
Nuclear Regulatory Commission
The Nuclear Regulatory Commission is an independent agency of the United States government that was established by the Energy Reorganization Act of 1974 from the United States Atomic Energy Commission, and was first opened January 19, 1975...
, reproduced in the table below. These are not all the isotopes disposed of at these facilities, just the ones that are of most concern for the long-term monitoring of the sites. Waste is divided into three classes, A through C, where A is the least radioactive and C is the most radioactive. Class A LLW is able to be deposited near the surface, whereas Classes B and C LLW have to be buried progressively deeper.
In 10 C.F.R. § 20.2002, the NRC reserves the right to grant a free release of radioactive waste. The overall activity of such a disposal cannot exceed 1 mrem/yr and the NRC regards requests on a case-by-case basis. Low-level waste passing such strict regulations is then disposed of in a landfill with other garbage. Items allowed to be diposed of in this way are: glow-in-the-dark watches (radium) and smoke detectors (americium) among other things.
| Radionuclide | Class A (Ci/m^3) | Class B (Ci/m^3) | Class C (Ci/m^3) |
|---|---|---|---|
| Total of all nuclides with less than 5 year half life | 700 | No limit | No limit |
| H-3 (Tritium) | 40 | No limit | No limit |
| Co-60 | 700 | No limit | No limit |
| Ni-63 | 3.5 | 70 | 700 |
| Ni-63 in activated metal | 35 | 700 | 7000 |
| Sr-90 | 0.04 | 150 | 7000 |
| Cs-137 | 1 | 44 | 4600 |
| C-14 | 0.8 | 8 | |
| C-14 in activated metal | 8 | 80 | |
| Ni-59 in activated metal | 22 | 220 | |
| Nb-94 in activated metal | 0.02 | 0.2 | |
| Tc-99 | 0.3 | 3 | |
| I-129 | 0.008 | 0.08 | |
| Alpha emitting transuranic nuclides with half life greater than 5 years | 10 nCi/g | 100 nCi/g | |
| Pu-241 | 350 nCi/g | 3500 nCi/g | |
| Cm-242 | 2000 nCi/g | 20000 nCi/g |
LLW should not be confused with high-level waste (HLW), spent nuclear fuel
Spent nuclear fuel
Spent nuclear fuel, occasionally called used nuclear fuel, is nuclear fuel that has been irradiated in a nuclear reactor...
(SNF) or transuranic waste
Transuranic waste
Transuranic waste is, as stated by U.S. regulations and independent of state or origin, waste which has been contaminated with alpha emitting transuranic radionuclides possessing half-lives greater than 20 years and in concentrations greater than 100 nCi/g .Elements having atomic numbers greater...
(TRU). These require different disposal pathways. TRU wastes from the US nuclear weapons complex is currently disposed at the Waste Isolation Pilot Plant
Waste Isolation Pilot Plant
The Waste Isolation Pilot Plant, or WIPP, is the world's third deep geological repository licensed to permanently dispose of transuranic radioactive waste for 10,000 years that is left from the research and production of nuclear weapons...
(WIPP) near Carlsbad, New Mexico
Carlsbad, New Mexico
Carlsbad is a city in and the county seat of Eddy County, New Mexico, in the United States. As of the 2010 census, the city population was 26,138. Carlsbad is the center of the designated micropolitan area of Carlsbad-Artesia, which has a total population of 55,435...
, though other sites are considering on-site disposal of particularly difficult to manage TRU wastes.
See also
- Radioactive wasteRadioactive wasteRadioactive wastes are wastes that contain radioactive material. Radioactive wastes are usually by-products of nuclear power generation and other applications of nuclear fission or nuclear technology, such as research and medicine...
- high level wasteHigh level wasteHigh level waste is a type of nuclear waste created by the reprocessing of spent nuclear fuel. It exists in two main forms:* First and second cycle raffinate and other waste streams created by nuclear reprocessing....
- transuranic wasteTransuranic wasteTransuranic waste is, as stated by U.S. regulations and independent of state or origin, waste which has been contaminated with alpha emitting transuranic radionuclides possessing half-lives greater than 20 years and in concentrations greater than 100 nCi/g .Elements having atomic numbers greater...
- spent nuclear fuelSpent nuclear fuelSpent nuclear fuel, occasionally called used nuclear fuel, is nuclear fuel that has been irradiated in a nuclear reactor...
- mixed wasteMixed waste (radioactive/hazardous)According to the United States Environmental Protection Agency, mixed waste is a waste type defined as follows; "MW contains both hazardous waste and radioactive waste . It is jointly regulated by NRC or NRC's Agreement States and EPA or EPA's RCRA Authorized States...
General references
- Fentiman, Audeen W. and James H. Saling. Radioactive Waste Management. New York: Taylor & Francis, 2002. Second ed.
- Jorge L. Contreras, "In the Village Square: Risk Misperception and Decisionmaking in the Regulation of Low-Level Radioactive Waste", 19 Ecology Law Quarterly 481 (1992) (SSRN)