[FoRK] Why Fukushima made me stop worrying and love nuclear power
dmorton at bitfurnace.com
Sun Mar 27 17:58:21 PDT 2011
On Sun, Mar 27, 2011 at 6:47 PM, Stephen Williams <sdw at lig.net> wrote:
> ... Additionally, the thorium-based system apparently "eats" other
>> radioactive waste, leaving much less than you started with.
> Regarding engineering against risk:
>> The progression to an acceptable "failsafe" level, is of course, an
>> incremental asymptotic pursuit. Due to cost considerations, you don't get to
>> design beyond a given expectation until it happens. At which point it is
>> essentially too late. There is zero possibility (here's the human factor) of
>> *actually building* anything that is inherently dangerous that covers all
>> the possible failure modes. By the time we get nuclear technology to the
>> point where we have, say, a one in 1000 year/1000 units failure rate, we may
>> well have long lost public interest in continuing.
> For certain kinds of reactors, including nearly all of those from the past,
> there are potentially bad failure modes that take a lot of layers of safety
> to make safe enough. However, many new reactor designs are immune or almost
> immune to melt-down. Some, especially the thorium-based systems, don't even
> involve any quantity of volatile isotopes. (Uranium is made and immediately
> consumed...) We designed a particular kind of reaction in the 40's and
> 50's, engineered a plant in the 60's, and we've been mostly stuck since then
> in evolving to where we could be. If you build a plant where any
> configuration of the elements is safe, how can anyone cling to the notion
> that "nuclear *" is inherently totally unsafe under any circumstances?
> (Rationally, you can't.)
Its probably worth adding some linkage to material about
(not-currently-manufactured) thorium reactors.
"""MSRs can be safer. Molten salts trap fission products chemically, and
react slowly or not at all in air. Also, the fuel salt does not burn in air
or water. The core and primary cooling loop is operated at near atmospheric
pressure, and has no steam, so a pressure explosion is impossible. Even in
the case of an accident, most radioactive fission products would stay in the
salt instead of dispersing into the atmosphere. A molten core is
meltdown-proof, so the worst possible accident would be a leak. In this
case, the fuel salt can be drained into passively cooled storage, managing
"""The Molten-Salt Reactor Experiment (MSRE) was an experimental molten-salt
reactor at the Oak Ridge National Laboratory (ORNL) researching this
technology through the 1960s; constructed by 1964, it went critical in 1965
and was operated until 1969.
The MSRE was a 7.4 MWth test reactor simulating the neutronic "kernel" of
aninherently safe epithermal thorium breeder reactor. It used three
fuels: plutonium-239, uranium-235 and uranium-233. The last, 233UF4 was the
result of breeding from thorium."""
The Liquid Fluoride Thorium Reactor: What Fusion Wanted To Be (55 mins)
Thorium Remix 2009 - LFTR in 16 Minutes
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