How much radioactive material is at the Fukushima plant?

On last night’s Rachel Maddow Show, Ms. Maddow provided some interesting information about how much radioactive fuel might be on site at the Fukushima Dai-ichi nuclear plant.  We’ve provided a quick overview below, but the show’s presentation and graphics are much better than what we can provide.  Click here to watch the segment on “How much radioactive material is at the Fukushima plant?”

Chernobyl180 tons of fuel exploded into the atmosphere

 

Nuclear fuel believed to be on site at Fukushima Dai-ichi**

 

No. 1

No. 2 No. 3 No. 4 No. 5 No. 6

Common spent fuel pond located somewhere on site

Reactor Fuel

70 tons

90 tons 90 tons * 90 tons 90 tons

130 tons

 
Spent Fuel Pools***

50 tons

100 tons 90 tons 130 tons 160 tons

150 tons

Unknown

Total

120 tons

190 tons 180 tons 220 tons 250 tons

280 tons

1,240 tons

*       Reactor No. 3 is reported to have reprocessed fuel which means there is a mixture of uranium and plutonium in the fuel rods.

**     This information was reported by HKN News Japan, and was verified by MSNBC through Japanese and American nuclear experts as being their best estimate of the nuclear fuel on site at Fukushima Dai-ichi.

***   The spent fuel is less hot and less radioactive than the reactor fuel in the core, but without knowing how old the spent fuel rods are there is know way to know what the total radioactivity house at the plant is.