Types of Fire Protection Measures for Fuel Cycle Facilities
The following types of fire protection measures are most often employed in fuel cycle facilities regulated by the U.S. Nuclear Regulatory Commission (NRC):
Administrative controls include combustible loading controls, ignition controls, operator actions, and manual fire suppression activities.
Active engineered controls include fire detection and suppression systems, as well as self-closing fire doors and dampers. In addition, for the proposed mixed-oxide (MOX) fuel fabrication facility, active engineered controls include "dynamic confinement" systems, equipped with high-efficiency particulate air (HEPA) filters. These dynamic confinement systems provide an important level of added protection because the MOX facility is designed to produce light-water reactor fuel by recycling plutonium that has been secured through international nuclear disarmament agreements.
Passive engineered controls normally include firewalls, penetration seals, and fire doors that are normally closed.
In addition to these standard types of fire protection measures, two additional types are used for the subset of NRC-licensed fuel cycle facilities that contain at least a critical mass of special nuclear material. The NRC regulates this subset under Subpart H of Title 10, Part 70, of the Code of Federal Regulations (10 CFR Part 70). Within that context, this subset of fuel cycle facilities uses the following two additional types of fire protection measures:
Items relied on for safety (IROFS) are used to meet the performance requirements of Subpart H, which limit the risk from individual events, including those initiated by fire.
Defense-in-depth controls include other controls related to the baseline design criteria of Subpart H, which require protection from fire and explosions to be explicitly considered in designing new facilities or new processes that are added to existing facilities.