Geological Disposal of Nuclear Waste
Geological Disposal of Nuclear Waste
19th Annual Symposium-Geological Disposal of Nuclear Waste
19th Annual Symposium-Geological Disposal of Nuclear Waste
The Nuclear Waste Management Organization (NWMO) is responsible for implementing Adaptive Phased Management (APM), Canada’s plan for the long-term care of the used nuclear fuel produced by Canada’s nuclear reactors.
Comments by John Greeves, Former Director, Division of Waste Management, NRC, presented to BRC Disposal Subcommittee
The study of geosciences and their relation to nuclear waste disposal and<br/>management entails analyzing the hydrology, chemistry, and geometry of the<br/>nuclear waste migration process. Hydrologic effects are determined by<br/>analyzing the porosity and permeability (natural and induced) of rock as well,<br/>as pressures and gradients, dispersion, and aquifer length of the system.<br/>Chemistry parameters include radionuclide retardation factors and waste<br/>dissolution rate.
Letter to The Honorable Nancy L. Kassebaum from J. Dexter Peach, Director, U.S. General Accounting Office
The U.S. Nuclear Regulatory Commission (NRC) is amending its regulations governing the disposal of high-level radioactive wastes in a proposed geologic repository at Yucca Mountain, Nevada. The final rule implements the U.S. Environmental Protection Agency’s (EPA’s) revised standards for doses that could occur after 10,000 years, but within the period of geologic stability.
This country report on Canada contributes to the InSOTEC research programme’s Work Package 1.1 which maps remaining socio-technical challenges to the implementation of geological disposal of radioactive waste in fourteen countries in the EU and North America (www.insotec.eu). The aim of this country report is to provide an overview of the current situation of geological disposal of High Level radioactive Waste (HLW) and Spent Nuclear Fuel (SNF) in Canada.
Deep geologic repositories are being widely studied as the most favored method of disposal of nuclear waste. Scientists search for repository sites in salt, basalt, tuff and granite that are geologically and hydrologically suitable. The systematic evaluation of the safety and reliability of deep geologic disposal centers around the concept of interacting multiple barriers. The simplest element to describe of the geologic barrier is the physical isolation of the waste in a remote region at some depth within the rock unit.
The first worldwide review of geological problems in radioactive waste isolation was published by the Ernest Orlando Lawrence Berkeley National Laboratory (Berkeley Lab) in 1991 (Witherspoon, 1991). This review was a compilation of reports that had been submitted to a workshop held in conjunction with the 28th International Geological Congress that took place July 9Ð19, 1989, in Washington, D.C.
Isolation in a geologic setting has been the generally favored solution to the high-level radioactive waste (HLW) problem since a scientific basis for nuclear waste management began to be formulated over half a century ago. Although general features of suitable settings have been enumerated, quantitative measures of the safety of geologic isolation of HLW are challenging to devise and to implement.
The research reported here was initiated in January 1980 and performed for the Office of Policy and Evaluation, U.S. Department of Energy. The study arises from recognition by the DOE that the resolution of institutional issues is vital to the establishment of facilities to dispose of high-level radioactive waste (HLW). The disposal of HLW is an intensely difficult public policy problem.
Congress designated Yucca Mountain, NV, as the nation’s sole candidate site for a permanent high-level nuclear waste repository in 1987, following years of controversy over the site-selection process. Over the strenuous objections of the State of Nevada, the Department of Energy (DOE) submitted a license application for the proposed Yucca Mountain repository in June 2008 to the Nuclear Regulatory Commission (NRC).
Fifty-four objectives were identified to guide the screening of the Nevada Research and Development Area of the Nevada Test Site for relatively favorable locations for the disposal of nuclear waste in a mined geologic repository. The objectives were organized as a hierarchy composed of 4 upper-level, 12 middle-level, and 38 lower-level objectives. The four upper-level objectives account for broad national goals to contain and isolate nuclear waste in an environmentally sound and economically acceptable manner.
The primary objective of government policy, and of NUMO in implementing this policy is to ensure that a repository for Japan’s high-level radioactive waste is designed and located so as to provide secure isolation of the waste and adequate safety for present and future generations. This requires that the site of a repository has to be chosen carefully and an associated repository concept is selected which is appropriate for its specific geological and environmental conditions. At NUMO, we have chosen to implement a volunteering approach to siting.
As nuclear power assumes an increasingly important role in meeting the nation's requirements for electrical energy, the quantity of radioactive wastes will also increase. The wastes of primary concern -<br/>designated "high-level" and "alpha" wastes - contain radioactive nuclides that decay so slowly as to require that they be isolated from the biosphere for thousands of years.
Consideration of the technical feasibility of Yucca Mountain in Nevada as the site for a high-level nuclear<br/>waste repository has led to an intense debate regarding the economic, social, and political impacts of the<br/>repository.
Geologic repositories for radioactive waste are evolving<br/>from conceptualization to the development of specific<br/>designs. Estimates of long-term hazards must be based<br/>upon quantitative predictions of environmental releases<br/>over time periods of hundreds of thousands of years and<br/>longer.
A method is presented for determining the relative favorability<br/>of geologically complex areas for isolating high-level<br/>radioactive wastes. In applying the method to the northeastern region<br/>of the United States, seismieity and tectonic activity were the<br/>screening criteria used to divide the region into three areas of<br/>increasing seismotectonic risk. The following criteria, specified by<br/>the U.S.
Programs to manage and ultimately dispose of high-level radioactive wastes are unique from scientific and technological as well as socio-political aspects. From a scientific and technological perspective, high-level radioactive wastes remain potentially hazardous for geological time periods—many millennia—and scientific and technological programs must be put in place that result in a system that provides high confidence that the wastes will be isolated from the accessible environment for these many thousands of years.