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PostPosted: Jul 14, 2010 6:45 pm 
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Here's a link to the YouTube video:
http://www.youtube.com/watch?v=DuLtlbEwM5Q#t=5m22s

That's a summary of her response. She was a bit more critical of nuclear than shown there, but I had to squeeze a LOT of footage down to fit the entire evening into an 11 minute summary. (11 minutes being the YouTube duration limit for most accounts.)

Her response doesn't strike me as unreasonable, but I'm not sure a wait-and-see approach (particularly if nuclear research funding is cut) will result in optimal problem solving pertaining to the climate crisis.

I guess I see it as: Billy Bob is a wind turbine fanatic. If the government decides solar is the way to go, and only funds solar research and solar industry, that doesn't mean Billy Bob is going to start researching solar panels.

Those who find LFTR technology compelling are only going to be fully utilized by letting them pursue that research. To enable that, Canada would need to be clear as to what safety and emission standards any nuclear technology must meet, and let those who believe they can meet such targets with their technology of choice, have at 'er.


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PostPosted: Jul 14, 2010 7:40 pm 
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It would not be unreasonable if:
1) no subsidies for the politically favored technologies
2) no windfall taxes for the successful technologies
3) there was a willingness to let the private investor get the rewards for the risks
4) the requirements for building an acceptable reactor were well defined.

In reality this isn't the case nor is it like to be. Even as a free market advocate I'm not sure I really want to let private companies own all rights to LFTR. I'm inclined to think it would be good for the government to fund more of the R&D so that the rights to them stays in the public domain available to multiple companies.


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PostPosted: Jul 14, 2010 8:04 pm 
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Location: Montreal
I just had supper.
You want me to watch Elizabeth May ?
Not likely :lol:


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PostPosted: Jul 14, 2010 8:29 pm 
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"You have this risk of critical mass because the core is plutonium."

This woman is an idiot and knows nothing. Normally I wouldn't consider ignorance so reprehensible but she pretends to be a leader on energy issues. She hasn't the first idea how a nuclear reactor works, and from the tone of her voice, she couldn't care less.


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PostPosted: Jul 14, 2010 9:29 pm 
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Kirk Sorensen wrote:
Emay - "You have this risk of critical mass because the core is plutonium."


That didn't sound right to me, but I wasn't 100% sure. At any rate there weren't follow up questions.

I'm not well versed in the technologies, but critical mass (or a runaway reaction of some sort is what she's talking about) is not impacted at all by what the fuel source is, correct?

You reach criticality to get the reactor to a near self-sustaining reaction, yes? And that is no big deal, and this is the (popular) misuse of the term, except that it has nothing to do with plutonium?

Some reactors have positive feedback loops (poorly designed), and some have negative feedback loops (proper design), and a positive feedback loop is what can lead to a "meltdown" if a poorly designed plant is not operating properly, not the type of fuel?


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PostPosted: Jul 14, 2010 10:36 pm 
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Location: Columbia, SC
gordonmcdowell wrote:
Kirk Sorensen wrote:
Emay - "You have this risk of critical mass because the core is plutonium."


That didn't sound right to me, but I wasn't 100% sure. At any rate there weren't follow up questions.

I'm not well versed in the technologies, but critical mass (or a runaway reaction of some sort is what she's talking about) is not impacted at all by what the fuel source is, correct?

You reach criticality to get the reactor to a near self-sustaining reaction, yes? And that is no big deal, and this is the (popular) misuse of the term, except that it has nothing to do with plutonium?

Some reactors have positive feedback loops (poorly designed), and some have negative feedback loops (proper design), and a positive feedback loop is what can lead to a "meltdown" if a poorly designed plant is not operating properly, not the type of fuel?


Any power generation reactor has to maintain a self sustaining fission reaction. This means that the number of neutrons produced from each fission event minus the losses exactly equals enough to keep the reactor maintaining a constant power level. The definition of a critical reactor is power level is constant. In a subcritical reactor the power level is dropping, and a super critical reactor power level is increasing.

All useful power generation reactors have to load extra fission mass into the core to operate for a normal fuel cycle. The analogy to your car would be you need a full tank of gas, not just enough to crank and start the engine for a few seconds. This excess reactivity as it is called must be accounted for in the design, and have proper methods (actually multiple methods) of control and shutdown. PWR/BWR's load enough fissionable fuel for eighteen months to three years of full power operation. CANDU's and some other power reactors have an advantage in that they can refuel online, so less excess reactivity needs to be in the core at any moment. It's actually quite stunning if you could compare the mountains of coal that a comparable size coal plant burns through with the amount of fuel a nuclear plant burns through in the same interval of for example two years.

This is a another significant advantage an LFTR would have over solid fueled conventional power reactors, the amount of excess fissionable material (or reactivity) can be kept to a bare minimum. You would concievably have enough fissionable material to run the reactor at full power for say three days. And every few hours days add some more as needed. If the addition operation is simple enough, you could add smaller amounts more often say 10-15 times a day. This would also have advantages from a reactivity control perspective.

In a reactor with a positive feedback on reactivity, the amount of excess reactivity available to fission is the extent of the consequences of an overpower excursion. Prevent positive feedback control and or minimize the amount of excess reactivity in the core to minimize any possible consequences of even the worst possible excursions.


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PostPosted: Jul 15, 2010 12:53 am 
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gordonmcdowell wrote:
Kirk Sorensen wrote:
Emay - "You have this risk of critical mass because the core is plutonium."



Some reactors have positive feedback loops (poorly designed), and some have negative feedback loops (proper design), and a positive feedback loop is what can lead to a "meltdown" if a poorly designed plant is not operating properly, not the type of fuel?


Are you referring to positive verses negative void coefficient?
http://en.wikipedia.org/wiki/Void_coefficient

a positive void coefficient is harder to control during a change in moderation yet might be cheaper to run.

Concerning jobs. The more jobs needed to generate the power the worse it is. Consider the jobs created to have everyone get on a bicycle powered generator every evening to supply the city power. Think of the number of jobs created and how green it would be. The jobs you want created is because the power is cheap enough to be used to make things. Consider a power source that is not a bicycle powered generator which allows you to read to your children every night that costs a nickel an hour to use and lasts 80 years.


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