Probably from the shut-down Humboldt Bay nuclear plant. Although the reactor has been shut down for years, the fuel rods are probably stored on-site in large vats of water until the Yucca Mountain repository is built.

So I guess the Novato crowd thinks that a one-time closely monitored rail movement would be worse than trucking the material out or shipping it by barge, and is cause to deny rail service to everyone in the region.