National Academy of Sciences: Demand for Californium-252 to rise.

[NNadir]

Californium-252
Californium-252 was first identified in the debris from thermo-nuclear test explosions. Currently ORNL produces about 0.25 grams of this isotope per year from SRS feedstock. The only other production is at Dmitrovgrad, Russia, which has a capacity of about one-tenth that of ORNL.

The primary use of Cf-252 is in brachytherapy for the treatment of certain cancers.4 In addition, during the past 45 years, Cf-252 has been used successfully for neutron radiography of objects ranging from flowers to entire aircraft; startup sources for nuclear reactors; and elemental analysis of coal, nuclear fuel, explosives, and the human body, among other uses (Osborne-Lee and Alexander, 1995). As noted earlier, the large demand for Cf-252 envisioned in the mid-1970s did not materialize. Recently, in treating muscular sarcomas; skin, head and neck tumors; and gynecological tumors, brachytherapy has shown high cure rates and lower recurrence rates compared to other treatment options such as surgery (Fontanesi et al., 1999; Maruyama, 1984 and Maruyama et al., 1986; Rivard et al., 1999; Taeev et al., 2001). Medical applications for radioisotopes are expanding rapidly (see Sidebar 7.1), and there appears to be a good possibility that there will be resurgence in the use of Cf-252.

Challenges and Opportunities for Preserving the Inventory

The higher actinides in the DOE inventory represent material that may be useful in its present form, may be suitable for target material, or may be essential for research into developing new materials...

This is one of the National Academy of Sciences Reports:

http://darwin.nap.edu/books/0309087228/html/74.html

Many years ago I relied on a mass spec that had a Cf-252 source for ion generation. This use has been supplanted by other techniques.

There is an interesting account earlier in the text about the production of 2.5 kg of Curium-244, which owing to its higher thermal output, was expected to replace plutonium-238 on spacecraft. This demand never materialized, possibly because it was easier and cheaper to obtain plutonium-238. Plutonium-238 is still used widely. The recent mission to Pluto recently launched is powered by plutonium as were the Pioneer Missions to the outer planets, the Voyager missions, the Cassini mission and the Galileo spacecraft.

Curium-244 is expected to accumulate in near ton quantities with the advanced fuel cycles that will be in use should humanity survive global climate change. Because of the neutronics of this isotope and its fairly high generation of spontaneous fission neutrons, this curium may be allowed to decay to Plutonium-240 before being placed back in the reactor for fuel recycling, where much of it will be fissioned after conversion to Pu-241.

Curium-244 has a thermal output of 2.8 watts per gram, meaning that a ton of it would put out almost 3 MW of heat continuously, simply from nuclear decay. The decay would lead to the formation of Helium and plutonium-240 which could be used to fuel other reactors and to denature weapons grade plutonium. (The half-life of Cm-244 is about 18 years.) Because curium is a very dense metal - 13510 kg m^-3 it offers the opportunity to make very compact high powered sources. A 3 MW power source composed of metallic curium would be a cube about 41 centimeters on a side. (It is probable that another geometry would be used to increase the leakage of neutrons and to prevent criticality.) It will be interesting to see if it will be economic to recover this energy for remote power applications. More than likely the first experience with this advanced fuel cycles will be in France, so it will be interesting to see how the French approach this potentially valuable isotope. The recovery of such heat would increase the amount of energy recovered from a kilogram of uranium, since it would not involve the fission of an actinide. The amount would be small, but still significant.

Depending on the type of cycle used, it may prove possible, if desired, to produce a few kilos of Californium-252, if nuclear energy is widely used using a closed fuel cycle and continuous recycling. I don't believe we would ever need that much, but you never know.

According to text elsewhere in this report, the expected demand for Neptunium-237 for use in spacecraft, the starting material for the production of Pu-238, is expected to be about 200 kg over the next 35 years.

This is a very interesting read.

[rzemanfl]

1. I understood the explanation of Bushcronium the first time I read

it but this went over my head. To avoid people asking for the link I will post it here, despite it being somewhat old.

A major research institution has just announced the discovery of the heaviest element yet known to science. The new element has been named "Bushcronium." Bushcronium has one neutron, 12 assistant neutrons, 75 deputy neutrons, and 224 assistant deputy neutrons, giving it an atomic mass of 311. These 311 particles are held together by forces called morons, which are surrounded by vast quantities of lepton-like particles called peons.

Since Bushcronium has no electrons, it is inert. However, it can be detected, as it impedes every reaction with which it comes into contact. A minute amount of Bushcronium causes one reaction to take over 4 days to complete when it would normally take less than a second. Bushcronium has a normal half-life of multiples of 4 years; it does not decay, but instead undergoes a reorganization in which a portion of the assistant neutrons and deputy neutrons exchange places. In fact, Bushcronium's mass will actually increase over time, since each reorganization will cause more morons to become neutrons, forming isodopes.
This characteristic of moron-promotion leads some scientists to believe that Bushcronium is formed whenever morons reach a certain quantity in concentration. This hypothetical quantity is referred to as "Critical Morass."

When catalyzed with money, Bushcronium activates Foxnewsium, an element which radiates orders of magnitude, more energy, albeit as incoherent noise, since it has half as many peons but twice as many morons.
Bushcronium can spontaneously transmute into Pandemonium.

[NNadir]

2. That sounds like a dangerous element.

Actually, having an element named after you is a high honor.

Some of the world's greatest scientific geniuses, Bohr, Einstein, Fermi, Meitner, Rutherford, Seaborg and Marie Curie have had elements named for them.

Somehow I think that there will never be a Bushnium of any type. All of people who had transuranium elements named for them loved science. Bush hates science.

[Dogmudgeon]

3. It's also a unique Quantum Sink

It's the only known substance that absorbs photons and emits an overpowering stench.

--p!