Disposing Of Nuclear Waste As Nuclear Fuel

Saige writes "Nuclear waste has been a contentious issue, recently culminating with fights in the government over Yucca Mountain in Nevada as a proposed storage site. Well, perhaps there's a better way to deal with nuclear waste -by using it in nuclear reactors. A nuclear scientist at the University of Maryland, has come up with CAESAR, a reactor that runs not on the standard U-235, but on U-238. U-238 makes up most of the fuel rods in current reactors, but doesn't contribute to the reaction, and ends up currently as waste." The Yahoo! story linked from this article doesn't seem to open, but here's a story at The Economist.

Comments

Weapons

[MacAndrew]

I think the really interesting thing here is that the reactor cannot be used as a breeder. That would make it an excellent candidate to require nations like North Korea to switch to. (If you think that's the way to go. NK is VERY energy poor now that the Russians no longer send oil. 60 Minutes did an excellent piece on them last night.)

All reactors IIRC produce some plutonium, from bombarded U-238 (virtually all Pu is manmade). Breeders produce a lot. The "waste" which is U-235 depleted but plutonium enriched must be further processed to produce weapons-grade material. For 25 years we have banned reprocessing even to the level needed for use as fuel because of the concern is could be stolen and further enriched. Some countries like France and Japan disagree and do reprocess. The scare in Japan last week illustrates the risk. Most people here would agree there' no such thing as perfect security, esp. with the universal hazards of corruption, accident, and incompetence.

Even if the thieves were unable to purify the material, it would make excellent "dirty bomb" material. Pu is not especially radioactive, absent heavy chain reaction, but it is very toxic and dangerous to ingest or inhale where it might lodge and expose sensitive tissue to prolonged damage.

It's a shame nuclear policy is so constrained by weapons issues.

Re:Weapons

[DuckDuckBOOM!]

I think the really interesting thing here is that the reactor cannot be used as a breeder.

...huh? Quote from The Economist article:

By adjusting the configuration of the core in the right way--by judicious positioning of graphite, for example--almost any civilian reactor can be made to produce plutonium, and thus to make weapons. Access to the core is not necessary with CAESAR, as it could run for decades without any need for refuelling. Thus it could be sealed. Countries could then adopt the design to show that their nuclear intentions were entirely peaceful.

The way I read this, the difference with CAESAR is that the fuel doesn't require periodic replacement, so the reactor could be sealed to prevent, e.g., terrorists from making off with plutonium-laden spent fuel. The key word here is "could". Nothing appears to prevent a gov't from designing a CAESAR to allow harvest of plutonium, or from covertly retrofitting a sealed reactor. (Granted, it almost certainly wouldn't produce as much Pu as quickly as would a fast breeder, but those are purpose-built devices that the nuclear powers would discover & stop in a heartbeat. And you don't need all that much Pu to build a bomb.) The sealed-fuel concept would work well if the government controlling it were trustworthy, or if verification methods were foolproof. Unfortunately, in the case of an Iraq or a N. Korea, those are mighty big IFs.