Saturday, March 26, 2011

#Fukushima I Nuke Plant: Plutonium Is Not Just in MOX Fuels in Reactor 3

My "Duh" moment.

Plutonium is not just in the MOX (Mixed Oxide) fuels that are used in the Reactor No.3. It is in the Reactor Pressure Vessels, and it is in the spent fuels stored (I hope) in the pools above (I hope) the Reactors No.1, 2, 3, 4.

Why? Because plutonium is a byproduct of uranium fission. Duh.

From World Nuclear Association's paper on Plutonium:

In practical terms, there are two different kinds of plutonium to be considered: reactor-grade and weapons-grade. The first is recovered as a by-product of typical used fuel from a nuclear reactor, after the fuel has been irradiated ('burned') for about three years. The second is made specially for the military purpose, and is recovered from uranium fuel that has been irradiated for only 2-3 months in a plutonium production reactor. The two kinds differ in their isotopic composition but must both be regarded as a potential proliferation risk, and managed accordingly.

Plutonium, both that routinely made in power reactors and that from dismantled nuclear weapons, is a valuable energy source when integrated into the nuclear fuel cycle. In a conventional nuclear reactor, one kilogram of Pu-239 can produce sufficient heat to generate nearly 10 million kilowatt-hours of electricity.

Plutonium and nuclear power

Plutonium is formed in nuclear power reactors from uranium. When operating, a typical 1000 MWe [megawatt electrical] nuclear power reactor contains within its uranium fuel load several hundred kilograms of plutonium.

So far, after more than 2 weeks since the first explosion (Reactor No.1) occurred, Fukushima I Nuclear Plant seems to have quieted down. Move on, nothing to see here.

It is possible that they are not telling us, but no, Japanese people are honest and hard-working, right? Right.


Anonymous said...

Only small amounts of Plutonium are made in light water reactors such as the Fukushima plant. Light water reactors are the perferred reactor design to avoid the production of plutonium. Reactors that are designed to produce plutonium use heavy water or liquid metals.

Chernobyl was a plutonium plant using the graphite pile design. At the type of the explosion the fuel rods contained elevated amounts of plutonium as the fuel had reached the end of its cycle and was going to be extracted in a few months time to harvest its Plutonium.

The biggest worry is the amount of cesium and iodine being released. Cesium 137 has a half-life of about thirty years. Land contaiminated by Cesium will be hazardous for hundreds of years until it transmutes into a non-radioactive isotope or becomes buried by nature over time. Think of a 20 to 40 mile radius that will need to be permanently abandoned. Real estate in Japan is already in short supply.

Every day Japan delays in burying the reactors just permits more fallout to contaiminate more land and at higher levels.

arevamirpal::laprimavera said...

I'm trying to find out how many tons of nuclear fuels (in use and spent). I saw a number somewhere and it was just stupendous I must have misread.

By the way, TEPCO took a soil sample at the plant to have it tested for plutonium, according to their latest press conference. See my post.

Anonymous said...

Plutonium probably originated from MOX Spent Fuel rods. What are the odds that TEPCO made a minor mistake and fuel the other reactors with at least some MOX Pellets.

arevamirpal::laprimavera said...

With TEPCO, anything is possible. They are not saying anything about what type of fuel rods are there in the Spent Fuel Pools.

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