Underground isolation of nuclear waste

A schematic diagram of the tentative plan for deep underground isolation of nuclear waste. Reproduced with permission from Chemical Engineering News, July 18, 1983, 61 (29), p. 30. Copyright 1983 American Chemical Society. 

More than 6 billion has been spent on high-level waste disposal. Spent fuel can be deadly for tens of thousands of years. In order to isolate it from the environment, nuclear waste is to be buried deep underground. Nevada s Yucca Mountain has been under consideration for decades and many in the nuclear industry believe that the Clinton administration blocked action on this site to gain support in this area. 

This experiment provides considerable confidence in the concept of waste immobilization in glass as one step toward isolating the long-lived radioactive by-products of nuclear power from man s environment. Of course, the immobilized material would not be placed deliberately in shallow ground water for permanent disposal. The consensus today is for deep underground disposal in a stable geological formation (21). 

In 1982, lawmakers passed the Nuclear Waste Policy Act, which established a program to build this countiy s first underground nuclear waste repositoiy, a permanent disposal site for nuclear waste. In 1987, Yucca Mountain, Nevada, was chosen for study as a potential site. The stable rock formations deep underground combined with sparse population and little rainfall make it an ideal location for the site. Nuclear waste will be encased in several layers of containment material and placed in tunnels drilled out of the rock formations 1000 ft beneath the ground. The storage facility should keep these materials isolated from us and from the environment for the foreseeable future. However, as might be expected, the construction of the facility is controversial, with many opposing even the idea. The facility had been scheduled to be operational in 2010, but delays have pushed back that date to 2017 at the earliest. 

The high-level radioactive wastes (HLW s) produced at nuclear power plants must be isolated from the population for an extremely long time, i.e., more than 10,000 years. There are plans to construct HLW disposal facilities in deep underground repositories. Thus, the safety of the barrier system must be evaluated for time scales in excess of 10,000 years this is beyond the scope of any conventional scientific experiment-based approach. We need to use an alternative method that is based on a macro-phenomenological approach. 

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