James ActonSilence is highly enriched uranium

I have to admit I’m quite surprised that my “long weekend“ post generated quite as much heated comment as it did. But that, I guess, is the pleasure of blogging on the Wonk.

Anyway, now for something completely different: highly enriched uranium (HEU) elimination. At a meeting in London a few weeks ago, a UK official said something I’d never heard before about HEU-fuelled submarine reactors. Discussing the issues surrounding the total elimination of HEU, the official said that he had received clearance to say that HEU-fuelled submarines have two advantages. First, they don’t need refuelling (which is widely known). Second, because the reactors are physically smaller they are quieter. I’d never heard this before but it certainly sounds plausible (although I’m not a reactor physicist).

This helps explain, I think, why the UK and US are as sensitive as they are about the issue eliminating HEU-fuelled naval reactors. Regardless of whether you think quietness is a good excuse for keeping them, the UK government deserves credit for explaining this and helping to inform the debate that little bit more.


  1. YardBird (History)

    Should I say simple conclusion here you must have missed.

    Lower enrichment implies larger bulk.

    More control rods and duplication of equipment, larger coolant pumps or more coolant loops.

    Physical size issues on a submarine which already has a cramped enough reactor compartment to work on making for complex maintenance.

    Just plain increased flow noises through the plant itself.

  2. James Acton (History)

    That was exactly why I said it was plausible. But as I’ve never worked on nuclear reactors I thought it prudent not to be too dogmatic…

  3. CKR (History)

    “Don’t need refuelling?” I suspect what was intended was more like “need refuelling less frequently.”

    Sorry, James, you’ll have to get a bit more educated on the science of these things. YardBird gives us the primary reason for high enrichment.

    Widely known? I suggest you google “submarine reactors refuelling” or some similar combination of words.

    Some of your readers actually have worked on nuclear reactors.