Anyone for shooting in ping pong balls and old tennis shoes to plug the crack?

There was a fire and hydrogen explosion reported earlier in the spent fuel pool of Unit 4. It's possible that the explosion cracked the stainless steel and concrete containment for that pool, or maybe coolant is leaking out one of the drain pipes, valves damaged in the explosion.

I'd not be surprised if the other spent fuel pools in units 1, 2, and 3, are similarly damaged.

And as we've mentioned above, that would be a major problem given the inventory of high level nuclear waste stored in these pools.

One would hope that such large spent fuel pools will no longer be designed so close to the reactor vessel. There needs to be a small spent fuel pool for temporarily storing the inventory of one reactor vessel but it should be transfered out to a more remote well protected spent fuel pool as soon as it has cooled sufficiently. That was the design of the Maine Yankee nuclear power plant, a pressured light water reactor constructed back in 1970 and decommissioned in 1996, and it would seem to be an improvement on the design of the Fukushima-1 Mark 1 reactors, and their sister reactors all around the world, including the 23 plants in the States.

Charley Noble