A probabilistic assessment code system for derivation of clearance levels of radioactive materials. PASCLR user's manual

It is indicated that some types of radioactive material generating from the development and utilization of nuclear energy do not need to be subject regulatory control because they can only give rise to trivial radiation hazards. The process to remove such materials from regulatory control is called as 'clearance'. The corresponding levels of the concentration of radionuclides are called as 'clearance levels'. In the Nuclear Safety Commission's discussion, the deterministic approach was applied to derive the clearance levels, which are the concentrations of radionuclides in a cleared material equivalent to an individual dose criterion. Basically, realistic parameter values were selected for it. If the realistic values could not be defined, reasonably conservative values were selected. Additionally, the stochastic approaches were performed to validate the results which were obtained by the deterministic calculations. We have developed a computer code system PASCLR (Probabilistic Assessment code System for derivation of Clearance Levels of Radioactive materials) by using the Monte Carlo technique for carrying out the stochastic calculations. This report describes the structure and user information for execution of PASCLR code. (author)