First you do understand that using these neutron absorbing fuel bundles was a kludge to ameliorate poor material performance in the pressure vessel walls. Neutron absorbing fuel rods also lower the fissile inventory of the core, making it less efficient, thus there is a performance trade off here.

Second a set of sponges is not the engineering equivalent to a shield, as one assumes that they are replaced as they become less effective through neutron activation. They are then treated one again assumes as spent fuel waste.

Lastly Western made reactor pressure vessels have very good lifespans even under high neutron fluxes, and they too have occasional heat-treatments to recondition them.

The point being that there is not yet a good material that will reflect neutrons, tolerate high temperatures, and that can be integrated into the walls of a pressure vessel. But I can assure you it hasn’t been from lack of effort.

I also like the old story of two monks who wondered how many teeth a horse has. A young novice heard that and suggested to find a horse and count the teeth. The munks get upset and told the novice, that the truth can only be found from old books.

So maybe I was too logical too, when thinking that a solution witch has worked in two nuclear reaktors (Loviisa 1&2) could possibly work in other reactors, too.

Or is the problem here, that this solution does actually not came from material science?

In that show, when ever there is a difficult technical problem Capt. Pickard turns to Jordi and Mr. Data and tells them in gruff tones to “make it so,” and two or three minutes later they have.

In real life, when it comes to material science, solving problems is as hardscrabble as it gets. “It should be possible,” has been the epitath written over the grave of many projects, and more that a few careers. It is foolish to trivialize materials as an engineering issue, or assume that anything you might think obvious, hasn’t been considered.

This is what has been done here in Finland at Loviisa nuclear power plant and it’s two VVER-440 reactors. The outer fuel bundles in the core are replaced with “dummy”-elements to reduce the neutron radiation to the pressure vessel. The damages already occured was repaired by a heat treatment.

But how about the MSR? Liquid fuel with some neutron radiation produced by spontanous fission all ower the system, also in the pressurised heat exhanger? No experiences about this yet?

I am a metallurgist, Hank and people in my field have been pulling their hair out by the handfuls for the last forty years looking for these materials. It is not a trivial problem. Neuron embrittlement, and neutron activation, and radiation creep all add to the difficulties, as ultimately does cost. Finding a balance between these and the other necessary properties is exceptionally difficult.

I might add that this search is not helped by the slow disappearance of high-flux research reactors, or their conversion in to low power sources in the name of controlling proliferation.

One suggestion–look at the development of high temperature metals.

The metallurgy is interesting because it’s required to handle the extremely high temperature of the latest super-supercritical coal plants.

It would be _very_ interesting to take that same material, as it’s being developed for use in ultra-high-temperature coal plants, and test it for neutron embrittlement.

Figure out how to make the material suitable for later use once in fission and eventually fusion reactors can be built that can operate at comparably high temperatures.

Coal plants being built now are going to be more thermodynamically efficient — because they can run hotter — than fission plants. This pushes the metallurgy.

(And will run even hotter, as materials allow, if plants ever get built that run on enriched air or pure oxygen instead of air (which would produce CO2 without nitrogen oxides, easier to sequester, if there ever is a way to sequester the stuff in volume)).

Besides, we’ll need the advanced metallurgy for starships …

Now for a bit of speculation on the PRISM design in this regard: I imagine that its designers took into account other fast reactor experience with neutron damage. Also, I don’t remember anything like the neutron embrittlement considerations that come into play in LWRs, perhaps because liquid metal cooled reactors are not pressurized so that the brittle pressure vessel problem is not a consideration with them. For fast reactors it must be pretty much just a distortion problem, which might be manageable by replacement or rework of components given appropriate design features.

First, producing enriched uranium or plutonium is a very costly process, as a result the product has considerable value to those that have made it. Consequently they are always treated as precious metals and accorded the security of such. In fact there has been no credible loss of fissionable material ever, even during the worst day of the collapse of the USSR, when one would assume stockpiles were at there most vulnerable.

Second, the threat from reactor-grade plutonium has been greatly exaggerated by the argument that what is theoretically possible to do with this grade of Pu.

Even if the question of suppling weapon-grade fissile material is removed, (which is the crux of the ‘dual use’ argument that these facilities help in the construction of a bomb) it still requires a sizable technological infrastructure and the expenditure of hundreds of millions of dollars to make a device. The costs of a more ambitious program aimed at producing a militarily significant number of weapons can easily run into the billions of dollars, and the idea that such a project could be carried out by surreptitiously from stolen material by a subnational group belongs in pulp novels, not in any rational discussion of the issue.

wonndnering if anyone can explain why South Korea has a 2028 timeline to demonstrate the technical and economic viability of operating burner reactors in conjunction with pyroprocessing? Why so long?
http://thebulletin.org/web-edition/op-eds/why-south-korea-needs-pyroprocessing

Another question – as i understand it, Plan Blees involves a major expansion of conventional reprocessing as well as the construction of an initial fleet of breeders (and/or Gen 3?). If so, is the argument that WMD proliferation risks increase in the short-term, if only marginally (reprocessing + breeders) but decrease in the medium- to long-term (IFR burners)?

Lastly, here are a couple of Blees’ quotes that Peter Lalor is referring to:
* In his book ‘Prescription for the Planet’, Blees argues that: “Privatized nuclear power should be outlawed worldwide, with complete international control of not only the entire fuel cycle but also the engineering, construction, and operation of all nuclear power plants. Only in this way will safety and proliferation issues be satisfactorily dealt with. Anything short of that opens up a Pandora’s box of inevitable problems.”
* Blees argues for a “nonprofit global energy consortium” to control nuclear power: “The shadowy threat of nuclear proliferation and terrorism virtually requires us to either internationalize or ban nuclear power.”

In the IFR and the S-PRISM maintaining a high transmutation rate with low inventory of actinides is the overall goal. This implies high fluxes. Thus the discharge burnup will be limited by criticality requirements and radiation damage effects. If the spectrum becomes “too hard”, then material damage limits become more severe; too soft and conversion doesn’t occur efficiently. These tradeoffs require detailed designs and strict operating envelopes in order to maximize costs and benefits.

That doesn’t mean fast reactors are dead in the water, but it does mean that this is a basic part of the picture with these types of reactor, and should be address in any series of essays devoted to the subject

The best I can suggest is a Google search on the subject is you want to familiarize yourselves with these matters.

Peter Lalor: “.. you and all other number-crunching techies” . What else would you like us to do with the numbers? Grow up.

Barry, you may of been distracted or I missed it, but we need (meaning me :) a good explanation of the differences between the IFR you and other advocate here, and the fast rector projects in Russia, India, etc. I would say India is the most advanced in *planning* their energy future based on FRs. Perhaps others can comments.

Government. Without governments, warts, blemishes and bureaucracy, there will be no IFRs. There would be no anything technological. Only the gov’t can garner the funds and minds necessary to develop the IFR (and LFTR and most other nuclear for that matter). Get over it. The people are going to DEMAND heavy government involvement, or you get companies like Kerr McGee and other *totally* profit driven loons in the industry and nobody is going to tolerate that.

David

“it is amusing how you and all other number-crunching techies and de facto free marketeers on this blog remain silent on the political matters raised by the Blog Patron Saint, Tom Blees, in his book.”

“If Technofixers claim”

“How naive does a blogger living in the Australian armaments capital of Adelaide”

Peter, you may have some worthwhile points buried in that rant, but given the insulting tone of your comment, I’m not going to bother to engage with you. Grow up and put aside your schoolboy level sneers if you want to engage people here in an intelligent discussion. Life’s too short to bother with pricks.

The anti’s often insist that massive efforts of an Apollo/Manhattan Project-like scale would plug the gaps and solve all of the technological/basic science vacuums associated with the renewable paradigm. Obviously it is rank hypocrisy not to apply the same logic to nuclear, but to point that out is a dead end… it feeds into their preference for emotional argument rather than logical debate.

Maybe a better way is to explain that huge crash programs such as the Manhattan Project are not appropriate to all scientific problems… in particular, such programs are unlikely to be effective in fields where the basic science is not yet in place. Rather, they are best suited to problems where the needs are primarily in the realm of engineering.

From this angle, the IFR tech is a much better candidate for such an effort compared and contrasted with the renewable scenarios, all of which require genuine theoretical “breakthroughs” in various and distinct disciplines in order to be viable… just a thought.

DV82XL – I was unaware that neutron damage was an unresolved and limiting factor… do you have a link or something where I could bone up on the issue? I don’t want to pester you with a bunch of questions…