Nuclear safety: Comparison of DOE's Hanford n-reactor with the Chernobyl reactor

GAO found that many differences exist between the Department of Energy's N-Reactor and the reactor near Chernobyl. One of the most significant differences involves the reactors' inherent physics responses to increases in coolant temperature. Other differences are (1) N-Reactor uses a metal form of uranium fuel, while the Chernobyl reactor uses an oxide form of uranium fuel and (2) N-Reactor uses once-through emergency cooling rather than a recirculating emergency cooling system like Chernobyl's. GAO found that the overall safety of N-Reactor relies heavily on successful operation of a different type of system - a reactor confinement system. N-Reactor has been operating 3 years beyond its expected life, and many systems and components are deteriorating. Maintaining safe operations through the mid-1990s will require considerable upgrading and rehabilitation. To extend safe operation of N-Reactor beyond the year 2000, major renovations - costing as much as $1.2 billion - will be required