nuclear-news

Nuclear Fuel Locations

The San Onofre nuclear plant near San Clemente, California is used to describe the nuclear reactor fuel locations and energy levels for this commentary. San Onofre has been permanently shut down, but data from when its reactors operated and for the spent fuel remaining onsite represent conditions at nuclear plants across the country……..  [excellent photos and tables]

……UCS Perspective

…… the relative hazards of nuclear fuel in reactor cores, spent fuel pools, and dry storage. Nuclear fuel in the reactor core, even in the core of a shutdown reactor, has a significantly higher energy level than when in the spent fuel pool or dry storage. The higher energy level has two associated hazard implications. First, it translates into less time to successfully intervene to prevent fuel damage when cooling is lost or impaired. Second, it provides a larger catalyst or engine to expel radioactive materials from damaged fuel. Risk is defined as the product of the probability of an accident times its consequences. The first factor affects the probability of an accident while the second factor affects its consequences. Combined, these factors can cause risk to increase.

Nuclear fuel in spent fuel pools has lower energy levels than when in reactor cores. The average fuel assembly energy levels are lower than the maximum energy level permitted in a MPC-37 canister. But the associated inventories indicate why spent fuel pools have higher risks than dry storage. The collective higher energy levels in spent fuel pools once again translate into less time to respond should cooling be lost or impaired. And the larger inventory of fuel assemblies emits a larger radioactive cloud should intervention fail.

Nuclear fuel in dry storage represents the least amount of fuel at the lowest energy level. If cooling is lost or impaired, more time is available to successfully intervene and less nasty spread gets out when efforts fail. But fuel in dry storage is far from absolutely safe. If it were even close to being so safe, the US would not be spending billions of dollars looking for, but not yet finding, a geological repository that can isolate this hazardous material from people and the environment for at least 10,000 years into the future.

Dry storage is the safest and securest way to manage nuclear fuel risks today. However, the more of the 10,000-year period we waste looking for a geological repository, the less competent and responsible we reveal ourselves to be.

We can do better. And not just because it would be hard for us to mess this mess up any worse than we’ve mismanaged so far. https://allthingsnuclear.org/dlochbaum/nuclear-waiting-gain