ASSESSMENT OF VENTILATION an‎d AIR CLEANING SYSTEM DESIGN APPROACHES FOR NUCLEAR SAFETY REQUIREMENT DURING ACCIDENTAL CONDITIONS IN NUCLEAR FUEL CYCLE FACILITIES

Safe operation of the nuclear and radiological facilities requiresconfinement of radioactive and toxic materials involved behind suitablebarriers which provide sufficient shielding. This is to minimize the internaland external radiation hazards at prescribed limits to protect plant workersand the environment according to ALARA principle. Most nuclearfacilities can expect to have at least one fire accident during its operatinglife. Such fire events are energized with the potential to damageconfinement barriers and transport radioactive materials out of thebuilding. This paper provides and evaluates four different design conceptsor safety performance approaches of the ventilation and air cleaningsystem (VACS) that can be used to achieve safety and adequate protectionin nuclear fuel cycle facilities during fire and accidental criticalityconditions. The paper presents a summary of the recent international requirements for ventilation and air cleaning system protection and adiscussion of selected fire protection considerations in designing nuclearfacilities. Also, it describes the possible fire protection approaches withtheir functional classifications and their engineered and administrativesafety features. Finally a conclusion of the selection of the best designconcept is recommended.