Monday, April 04, 2011

Blue Light Not So Special

In my recent post Blue Light Special I said that the blue lights seen at the reactor accidents in Japan were evidence of a criticality accident. But not so fast. Maybe, despite the reports there were no blue lights.

In fact, nobody has seen any flashing lights. It is speculation on what may or may not be happening:
A partial meltdown of fuel in the No. 1 reactor building may be causing the isolated reactions, Denis Flory, nuclear safety director for the U.N.’s International Atomic Energy Agency, told a news conference in Vienna.

Nuclear experts call these reactions “localized criticality.” They consist of a burst of heat, radiation and sometimes an “ethereal blue flash,” according to the U.S. Energy Department’s Los Alamos National Laboratory website. Twenty-one workers worldwide have been killed by “criticality accidents” since 1945, the site says.
An expert says there is a chance of such a reaction. Sometimes, that kind of reaction will include a blue flash of light inside the reactor. So, following Fox logic….OH MY GOD – BLUE FLASHES OF LIGHT OVER NUCLEAR PLANT!!
So no blue flashes.

What do we have some evidence of?

Chlorine 38 - a short half life isotope made by irradiating sea water with neutrons
Iodine 134 - a short lived decay product
Neutrons - to be detected at the approximately 1 mile distance from the plant reported there needs to be a high level source of neutrons - like a critical core or something.
Tellurium 129 - a short lived decay product found recently in reactor #1
Much higher levels of Iodine 131 in core #1 than in cores #2 and #3. The levels should be comparable if all the reactors shut down with the earthquake.

You can learn more about the last two items at Chain Reactions.

So no blue light, but still a lot of evidence of an inadvertent criticality accident.

Cross Posted at Classical Values


Anonymous said...

What conditions would lead to an "urgency" to dump radioactive water in ocean now rather than wait for tanks that were ordered? Not sure I buy their explanation. Also, there was an earlier reference to avoiding a "more serious risk."


M. Simon said...


Obviously they are leaking high quantities of much more radioactive water.

What I don't get is why they haven't ordered an oil tanker plus ferry barges.

I have no idea about the "more serious risk". It could be a lot of things. But TEPCO isn't talking.

Maybe their plan is to keep as much as possible of the junk on site. But if they have to cool that stuff for 24 months they are going to need a LOT of tankage.