Step-by-Step Solution to the Project on Long-Term Storage of Spent Fuel from Nuclear Submarines with Heavy Liquid Metal Cooled Reactors

Abstract

It is Alfa class Nuclear Submarines (NS) with heavy liquid metal lead-bismuth coolant in the primary circuit of the nuclear reactor that have been put into operation in Russia at the height of Cold War. The particular feature of such NSs was that the reactor cores while refueling have been unloaded in the form of a single removable block, including reactor core with inserted control rods, reflector, and the upper closure fitting of the biological shielding. So, in fact, it was the unloading of a subcritical reactor. The unloaded spent removable blocks (SRB) are currently stored at one of the North naval bases on the Kola Peninsula. Our expertise shows that a) a rather high-level of radioactivity is accumulated in the single SRB; b) the stored SRB have a relatively low sub-criticality that is sensitive to the exposure of adverse external conditions; c) the technology of SRB storage preparation does not exclude the possibility of water penetration into the SRB volume. Thus, the stored SRB are the source of potential nuclear and radiation danger. The International Project of the step-by-step solution of this problem is disscussed and the technological and other challenges that the Project faces in its realization are analyzed.