Saturday, 5 August 2017

Problems with Thorium


A Thorium fuel cell is a back hand way to uranium fission.

Disadvantages[edit]

There are several challenges to the application of thorium as a nuclear fuel, particularly for solid fuel reactors: In contrast to uranium, naturally occurring thorium is effectively mononuclidic and contains no fissile isotopes; fissile material, generally 233U, 235U or plutonium, must be added to achieve criticality. This, along with the high sintering temperature necessary to make thorium-dioxide fuel, complicates fuel fabrication. Oak Ridge National Laboratory experimented with thorium tetrafluoride as fuel in a molten salt reactor from 1964–1969, which was expected to be easier to process and separate from contaminants that slow or stop the chain reaction.
In an open fuel cycle (i.e. utilizing 233U in situ), higher burnup is necessary to achieve a favorable neutron economy. Although thorium dioxide performed well at burnups of 170,000 MWd/t and 150,000 MWd/t at Fort St. Vrain Generating Station and AVR respectively,[5] challenges complicate achieving this in light water reactors (LWR), which compose the vast majority of existing power reactors.
In a once-through thorium fuel cycle the residual 233U is a long-lived radioactive isotope in the waste. Another challenge associated with the thorium fuel cycle is the comparatively long interval over which 232Th breeds to 233U. The half-life of 233Pa is about 27 days, which is an order of magnitude longer than the half-life of 239Np. As a result, substantial 233Pa develops in thorium-based fuels. 233Pa is a significant neutron absorber and, although it eventually breeds into fissile 235U, this requires two more neutron absorptions, which degrades neutron economy and increases the likelihood of transuranic production.
Alternatively, if solid thorium is used in a closed fuel cycle in which 233U is recycledremote handling is necessary for fuel fabrication because of the high radiation levels resulting from the decay products of 232U. This is also true of recycled thorium because of the presence of 228Th, which is part of the 232U decay sequence. Further, unlike proven uranium fuel recycling technology (e.g.PUREX), recycling technology for thorium (e.g. THOREX) is only under development.
Although the presence of 232U complicates matters, there are public documents showing that 233U has been used once in a nuclear weapon test. The United States tested a composite 233U
-plutonium bomb core in the MET (Military Effects Test) blast during Operation Teapot in 1955, though with much lower yield than expected.[21]
Though thorium-based fuels produce far less long-lived transuranics than uranium-based fuels,[16] some long-lived actinide products constitute a long-term radiological impact, especially 231Pa.[17]
Advocates for liquid core and molten salt reactors such as LFTRs claim that these technologies negate thorium's disadvantages present in solid fueled reactors. As only two liquid-core fluoride salt reactors have been built (the ORNL ARE and MSRE) and neither have used thorium, it is hard to validate the exact benefits.[5]
India has a Thorium reactor working, and more problems will become apparent. The fission chain is about 20 million years. So the waste has to be safely stored for 800,000 times as long as human society has existed.
Less fatal than uranium fission – which requires insurance of 100 billion. Problems with world terrorism means a Thorium-based reactor ONLY needs an impossible annual insurance of 40 billion.
A much better idea isa plasma burn. A steam plasma at 4 atmospheres takes a fulse of power from a fluorescent light starter, then run unpowered.
Converting 5x10-15cc of regular water a year into 1.2MW of heat. A 12% efficient thermoelectric generator will produce 288kW.
The top side for home power production. The national grid will pay us 886,220 UK pounds annually for this power. Why bother working?
No large engineering plant or radioactive materials.
1 H2O+PL->E3+L+X-rayPL=plasma

The plasma converts the matter into massive heat, light and X-rays.

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