Concluding Observations
Milton Levenson
Bechtel International (retired)
It was not the objective of our workshop to achieve consensus on what is the best or optimum permanent solution to the spent nuclear fuel and high-level radioactive waste disposal problem. There are currently several alternatives—each with its own group of advocates. In some countries one option has been selected by policy officials while in other countries the decision has been deferred. It is not my intent to comment on the appropriateness of either selection by policy or deferral by policy but rather to give my personal observations on the content of the discussions at the workshop.
-
There were differing opinions as to what was the best or most appropriate final end point (for example, spent fuel geological disposal, reactor burn-out of actinide, accelerator burn-out of low-level fission products), but there was complete agreement that long-range storage and preferably centralized storage was required in all cases.
-
No one is against either reactor or accelerator burn-up or transmutation, but many have not decided on the practicality of it. This is probably due to the early stage of the science and lack of demonstration feasibility, which means estimates of cost are not credible.
-
There seemed to be concurrence that no matter how safe geological disposal is, it is prudent to minimize the amount of disposal to the extent that is practical.1
-
Over five decades of experience confirms that shipment of either spent fuel or high-level waste can be conducted safely although the advent of terrorism now causes a rethinking of the most appropriate methods of transportation.
-
Spent fuel and high-level waste are both currently being stored safely
-
under conditions that appear to be stable for as long as 50 years. The acceptable time may be much longer, but longer periods have not yet been validated.
-
Permanent solutions other than geological disposal of spent nuclear fuel, such as closed fuel cycles or transmutation, require significant research and development before they can be applied. It is not clear that funding at the levels required will be available to develop the technology in a timely manner. This supports observation 1 above.
-
Among the many considerations in the selection of a site the relationship of the chemistry of the host matrix to the chemistry of the waste form should be considered. In those cases where basic chemistry favors retention of fission products, plutonium, and actinides, natural barriers are important.
-
Since concerns over proliferation and terrorism, which were not discussed at the workshop, are current and since permanent solutions are in the future—an indeterminate time in the future—centralized, secure, long-term storage would appear to be of the highest priority.