Review of Plant Design Features Facilitating Decommissioning

Summary

At the design stage it is necessary to define the decommissioning strategy. This offers the opportunity to influence the design and hopefully deduce the optimum dismantling sequence, in terms of cost, dose rate and time.

The decommissioning activity will be some 50 years to 150 years in the future, though the strategy must be based on present known or developing technology. In the event, the developments in remote handling techniques must mean the assumptions in this paper are pessimistic.

Throughout the paper, delayed decommissioning is assumed, though a major accident or pressure for early re-use of the site, could require earlier decommissioning. This aspect is not considered in the paper, nevertheless, the conclusions would not be invalidated by such a requirement.

A schedule of design features which facilitate decommissioning and details of some specific items installed to aid decommissioning of Advanced Gas Cooled Reactors is presented.

The problems of long term storage of decommissioning documents and the selection of material for storage, can be influenced at the design stage. Some suggestions regarding storage and eventual recovery of information to aid decommissioning is included.