This will be a largely technical diary that will be devoid of my usual "cute stuff."
In a rather large victory in the battle against global climate change, Japan has produced its first MOX (Mixed Oxide Powder) from spent nuclear fuel. For those who are not familiar with what MOX fuel it is, it is a type of nuclear fuel that contains plutonium produced in commercial nuclear reactors.
Japan has previously recycled its spent nuclear fuel in France's La Hague and at the Sellafield plant in the UK, as part of the Japanese commitment to derive the maximum benefit from it's uranium. (There was a huge stir about forged documents at Sellafield involving Japanese fuel.)
The Japanese plant offers some rather interesting features that have not been commercially practiced before. The most interesting is the recovery of the uranium as well as the plutonium from its spent fuel.
As it happens, the vast majority of the material is so called "nuclear waste" is unfissioned uranium, which represents about 95% of the mass of the spent fuel. In other recycling strategies, this uranium is generally not recycled, but is stored for "later use."
The main reason for the choice to not use uranium that has passed through a reactor one time involves reactor physics. Once it has been through a reactor one time, the uranium is not exactly like the uranium produced in an enrichment plant. Typically the uranium produced in an enrichment plant is a mixture of the three naturally occurring isotopes of uranium, U-238, U-235, and U-234. The uranium fuel found in a nuclear reactor is typically enriched in the latter two isotopes. After irradiation of periods approaching two years, the uranium removed from the reactor contains a fourth isotope, uranium-236, which does not occur on earth in significant quantities. U-236 is a "neutron poison" or "neutron sink" that involves special considerations in reactor operations.
However U-236 offers very profound non-proliferation value, since its effect is to make any plutonium found in the reactor effectively useless for use in nuclear weapons.
The Japanese plant is superior to any previous nuclear fuel recycling plant because it never isolates pure plutonium, reactor grade or otherwise. This is a wonderful approach that accomplishes several things in one fell swoop. 1) It extends nuclear resources and reduces the need for additional uranium mining. 2) It greatly reduces the volume and mass of so called "nuclear waste." 3) It severely limits access to pure plutonium of any grade. 4) It assures that any plutonium that exists will generate significant decay heat and considerable radiation, making the unlikely diversion of the fuel to weapons - already a tiny risk - even more unlikely and far more problematic.
I knew this plant was coming on line, but I had no idea that it had a far superior process to the highly successful La Hague plant in France, and the somewhat less successful Sellafield plant in the UK.
I'm very, very, very impressed.
Japan has been making some rather remarkable strides in the field of nuclear energy. In Japan as elsewhere, the nuclear industry has been subject to a lot of criticism from people who actually know zero about the subject - Greenpeace and similar types - but, nevertheless, the Japanese have largely shrugged off these appeals to ignorance and continued to expand their nuclear capability.
Because of regulatory laxness, Japan will have some distance to travel before they are on the same level as France, France being the nuclear standard to which all other nations should aspire, but let me tell you, I have been waiting some time to see the approach that the new fuel recycling plant will be taking. This is state of the art, a very, very, very good piece of news in an increasingly troubled time.
The plant will have the capacity to recycle 800 metric tons of spent nuclear fuel per year, about 80% of all the fuel generated in Japan.
By clicking on the link above, one can see the building that holds all of the spent fuel produced per year in Japan. This building is relatively small, as one can see, and it readily accentuates why nuclear power has far lower external costs than any other form continuous of energy available on an exajoule scale. Nuclear energy is the only form of energy which produces "wastes" that can easily be contained in a small volume. I would submit that a single coal plant that had 1/1000 th the amount of energy output that this plant represents would have a waste heap that would dwarf this building.
To repeat: I am very, very, very impressed.