Is PRISM a better alternative to fusion?

[greswd]

http://gehitachiprism.com/what-is-prism/how-prism-works/
Said to be able to generate very little nuclear waste. Highly energy efficient.

Given the technical challenges of nuclear fusion, will PRISM be a more easily manageable alternative?

 

[Astronuc]

Said to be able to generate very little nuclear waste. Highly energy efficient.

Certainly 311 MWe from 840 MWt is approximately 37% thermal efficiency, so it is more efficient than most LWRs (at least on paper). I'm not sure about the claim of very little nuclear waste, since the fission of 1 fissile atom of U or Pu, or TU will produce two fission products. And we can add the activated cladding and structural materials in and around the core, so there will be a fair amount of waste. It would seem that the fuel cycle involves reprocessing, so the separated fission products would in theory be calcined and vitrified, and then placed in some geological repository. It would be interesting to see if there would some effort to separate out the rare Earth and certain transitional metal elements.

PRISM is based on proven technology, so it is probably more likely to build an electrical generating station with PRISM that can generate electricity well before we can generate electricity with fusion.

This topic is more one of engineering than high energy, nuclear or particle physics, so I'm inclined to move it to the nuclear engineering forum.

 

[greswd]

because the naysayers say ITER is a waste of money and will never succeed, and that we should just use PRISM for our energy needs.

 

[mfb]

For every project there is someone saying it won't succeed. Every US citizen pays (averaged over the population) 50 cents per year for ITER. Is that too much for the possibility to have a completely new type of power plant in a few decades? Costs per person are a bit higher for EU citizens, but I'd still happily pay twice that amount to build a second one (or for a construction start 10 years earlier... but it is too late for that).

 

[Vanadium 50]

The political challenge with fast reactors is substantially harder than with conventional fission reactors. And how many of those has the US built in the last 30 years?

 

[Astronuc]

As far as I understand it, GE Hitachi is proposing to use a PRISM system to consume the UK Pu stockpile. A parallel benefit would be electricity generation.
http://gehitachiprism.com/wp-content/uploads/2015/03/Prism_130315_022.pdf

http://gehitachiprism.com/what-is-prism/public-comment-on-prism/

Technically, it should work. There is sufficient experience with fast reactors.

 

[mheslep]

The political challenge with fast reactors is substantially harder than with conventional fission reactors. And how many of those has the US built in the last 30 years?

All the more reason for engineers and scientists to debunk flawed technical objections made for political reasons. In the US, the light water reactor is probably an economic dead end due to cost and an unresolved waste stream, while the regulatory community states it won't tolerate anything but more light water reactors for the "foreseeable future", and the fossil fuel industry has a long history of http://atomicinsightscom.c.presscdn.com/wp-content/uploads/Atom-Power-Assailed.png (1958, NYT). Yet advanced nuclear is the only serious way forward for de-carbonizing advanced economies.

 

[mheslep]

For every project there is someone saying it won't succeed. Every US citizen pays (averaged over the population) 50 cents per year for ITER. Is that too much for the possibility to have a completely new type of power plant in a few decades? Costs per person are a bit higher for EU citizens, but I'd still happily pay twice that amount to build a second one (or for a construction start 10 years earlier... but it is too late for that).

The 50 cents is just the visible cost. A more opaque cost of big science like this is that it starves funding for alternatives, makes them appear fringe. The ITER design with low power density, first wall problems, and fuel breeding problems, seems to provide no path to an economic power reactor. Thus even if ITER manages a couple minutes of stable operation in 15 years, the 50 cents plus the opaque costs might be high indeed.

 

[mfb]

With that argument, you can assign arbitrary costs to everything. I don't think that helps.

ITER has challenges - sure. If it wouldn't have them, there would be no point in building it.

 

[mheslep]

The big science problem introduced by ITER to fusion physics is not universal to every field of scientific or engineering endeavor; on the contrary, its fairly uncommon.

While I grant that the big science downsides are hard to quantify, that does not then mean that the 50 cents / head ITER assessment is the only cost. Throwing it around encourages the idea that it is.

 

[mfb]

The difference between "we do not build ITER" and "we build ITER" is 50 cents/year. The difference to "we build something else" is different, but that is not the question I answered.

 

[mheslep]

The first premise, do/do not, is not real. There is always opportunity cost. That is, there was never a large group of scientists and engineers and funds all sitting idle but for ITER. ITER redirected resources.

https://en.m.wikipedia.org/wiki/Frédéric_Bastiat#.22What_is_Seen_and_What_is_Unseen.22