Public Health and Environmental Radiation Protection Standards for Yucca Mountain, Nevada (40 CFR Part 197)
Yucca Mountain, Nevada is the Department of Energy’s (DOE) potential geologic repository designed to dispose of spent nuclear fuelspent nuclear fuelFuel that has been withdrawn from a nuclear reactor after use. It is still highly radioactive. and high-level radioactive wastehigh-level radioactive wasteHighly radioactive materials produced as a byproduct inside nuclear reactors. Other highly radioactive materials can be designated as high-level waste, if they require permanent isolation.. EPA's role at the proposed Yucca Mountain repository was to set standards to protect public health by limiting the radiation exposure to individuals living closest to the facility and most likely to be exposed to releases of radioactive material. EPA’s standards address all environmental pathways, including air, ground water and soil. The standards:
- Set a dose limit to reasonably maximally exposed individual of 15 milliremmilliremThe millirem is the U.S. unit used to measure effective dose. One millirem equals 0.001 rem. The international unit is milliSievert (mSv). per year (150 microsieverts per year) for the first 10,000 years after disposal.
- Set a dose limit of 100 millirem per year (1 millisievert per year) between 10,000 years and 1 million years.
- Take into account exposure through all potential pathways, and account for releases caused by a borehole going through a waste container and into the underlying ground water (the “human intrusion” standard).
- Require DOE to assess the effects of climate change, earthquakes, volcanoes, and corrosion of the waste packages on the performance of the repository system during the 1 million-year period.
- Set the following limits on radionuclides in ground water for 10,000 years of undisturbed performance of the repository:
|Radionuclide or type of radiation emitted||Limit||Is natural background included?|
|Combined radium-226 and radium-228||5 picocuries per liter||Yes|
|Gross alpha activity (including radium-226, but excluding radon and uranium)||15 picocuries per liter||Yes|
|Combined beta and photon emitting radionuclides||40 microsieverts (4 millirem) per year to the whole body or an organ, based on drinking 2 liters of water per day from the representative volume||No|
The U.S. Nuclear Regulatory Commission would implement these regulations at Yucca Mountain if a repository were to be established there.
The standards currently in place are the result of a revision issued in 2008. The 2001 disposal standards included a 10,000-year compliance period for protection of individuals and ground water resources from potential release of radionuclides from Yucca Mountain. EPA required dose projections beyond the 10,000-year compliance period, but did not establish a specific compliance standard for the longer-term projections.
In July 2004, the U.S. Court of Appeals for the District of Columbia Circuit ruled that the 10,000-year time period was inconsistent with recommendations made by the National Academy of Sciences (NAS) in a 1995 report. The NAS had recommended that EPA set a standard to limit exposure to individuals at the time of peak risk. The Court did not rule that EPA’s standard was not protective. It ruled that the EPA standards were invalid to the extent that they did not extend to the time period recommended by the NAS.
The 2008 standards maintained all the protections from the 2001 rule, but added 100 millirem per year dose limit beyond 10,000 years up to 1 million years.
The site was intended to be the nation’s first geological repository for disposal of this type of radioactive waste. This waste is currently stored at facilities in 43 states. DOE currently has no plans to open the site.