Software and hardware package for justification of safety of nuclear legacy facilities

Determination of future fate for nuclear legacy facilities is becoming an extremely important near-term issue. This includes decommissioning options to be identified based on detailed justifications of respective designs. No general practice has been developed in Russia to address such issues, while the initial steps to this end have been made as part of the federal target program “Ensuring Nuclear and Radiation Safety for 2008 and Up to the Year 2015”. Problems arising in justification of decommissioning options for such facilities, in terms of radiation protection and safety assessments both for the public and personnel, differ greatly from tasks involved in design of new nuclear installations. The explanation is a critical shortage of information on both nuclear legacy facilities as such and on the RW they contain. Extra complexities stem from regulatory requirements to facilities of this type having changed greatly since the time these facilities were built. This puts priority on development of approaches to justification of nuclear, radiation and environmental safety. A software and hardware package, OBOYAN, has been developed to solve a great variety of tasks to be addressed as part of this problem based on a combination of software and hardware tools enabling analysis and justification of the NLS safety in their current state and in a long term. The package's key components are computational modules used to model radiation fields, radionuclide migration and distribution of contamination in water and air, as well as to estimate human doses and risks. The purpose of the study is to describe the structure and the functional capabilities of the package and to provide examples of the package application.