Deactivation of the first loop of a decommissioned dual-purpose industrial reactor

The last few years have been marked by the decommissioning of Russian industrial uranium-graphite reactors, including dual-purpose reactors which not only produce plutonium but also generate thermal and electrical energy. In 1990, the first Russian dual-purpose reactor was removed from service at the Siberian Chemical Combine, after 32 years of accident-free operation. In the first stage, the basic reactor equipment is preserved to prevent the environmental release of radioactivity. The next step is to dismantle the system, and utilize those components that are not contaminated by radioactivity. In this context, the deactivation of the primary loop piping and equipment for safe dismantling and the subsequent preparation of the metal for reuse is of primary importance. The technology must include procedures for dealing with the radioactive liquid waste produced. This is the first time that this deactivation process has been attempted in Russia, and it must meet the appropriate radiational and ecological safety standards, as well as economic criteria. The ultimate goal of this stage is to remove all the contaminated equipment from the reactor site. It is economically expedient to recycle the metal. This article summarizes technology proposed for the deactivation of the first loop of a dual-purpose industrial uranium-graphite reactor, including reprocessing and subsequent solidification of the liquid radioactive waste formed. The deactivation permits dismantling of the equipment, its removal from the reactor site, and reuse of a considerable quantity of the metal