LONG-TERM SAFE STORAGE AND DISPOSAL OF SPENT SEALEDRADIOACTIVE SOURCES IN BOREHOLE TYPE REPOSITORIES

摘要

Borehole disposal of spent sealed radioactive sources (SRS) has a number of noticeableadvantages:? Effective radiating protection;? Long-term safety of disposal.? Operational safety;? Easy in operation;? Conceptually simple;? Simplicity of a design;? Easy of erection;? Practicability practically everywhere;? Low cost;? Long practice of application;? Retrievable (the new project);? Ease in improvement;Russian Federation has the leading experience in applying borehole storage/disposal methodfor SRS. A new immobilisation technology for sources being disposed of in undergroundrepositories was mastered by 1986 and since then it is used in the country. This method usesall advantages of borehole type repositories supplementing them with metal encapsulation ofsources. Sources being uniformly allocated in the volume of underground vessel are fixed inthe metal block hence ensuring long-term safety. The dissipation of radiogenic heat from SRSis considerably improved, radiation fields are reduced, and direct contact of sources to anenvironment is completely eliminated. The capacity of a typical borehole storage/disposalfacility is increased almost 6 times applying metal immobilisation. That has made newtechnology extremely favourable economically. The metal immobilisation of SRS isconsidered as an option in Belarus and Ukraine as well as Bulgaria. Immobilisation of sourcesin metal matrices can be a real solution for retrieval of SRS from inadequate repositories.