UK Scientists Designing Cement To Safely Store Nuclear Waste For 100,000 Years (ibtimes.co.uk)

An anonymous reader writes: A team of British scientists are working on designing a form of cement which could safely withstand the harmful effects of nuclear waste for thousands of years. The team at the UK's synchrotron science facility, Diamond Light Source, said the project will be vital as Britain looks to expand on its nuclear industry.

The team believe the new material is 50% better at reducing the impact of radiation than current storage solutions. The government is set to choose a location of where to store the estimated 300,000 cubic metres of radioactive waste which is estimated to have been accumulated by the UK by 2030.

Comments

Utter Stupidity

[Anonymous Coward]

Why don't these idiots use that "waste" as fuel for breeder reactors? They are throwing away 98% of their fissile material and worse, trying to make 100,000 year plans for it.

Re:Utter Stupidity

[careysub]

Cue the knee-jerk fuel-reprocessing-and-fast-reactor-is-the-complete-solution-to-all-nuclear-waste-problems-everywhere nutter comment.

Pointing out the problems with this comment is a bit of a problem in itself knowing what I should start with.

First, the 200,000 cubic meters of high-level waste already exists and is the product of the British nuclear weapons program, and possibly some of the high-level waste already created by fuel reprocessing. This stuff is a radiological and chemical witches brew that cannot be easily treated in any way. Some means of reducing this stuff to a stable state for long term storage is essential.

Second, there are only three operating (or soon to be operating) commercial scale breeder reactors in the world, two in Russia (operating) and one in India (not yet operating). A non-existent world fleet of breeder reactors cannot solve any real existing problems. Building a world-wide industrial deployment of breeder reactors is an exercise orders of magnitude more costly than waste disposal problems.

Third, breeder reactors do not make fission products go away. These must still be disposed of once the actinides are burned.

Fourth, fuel reprocessing systems currently operating produce larger volumes of high-level waste in physical terms than they take in. This must be converted to some form that be stored long term (see point one, above).

Fifth, spent fuel from power reactors does not contain "98% of their fissile material". Real nuclear fuel today is enriched to about 4% U-235 for loading (96% U-238), plutonium is bred and burned in place so that 5% of the actinide content is consumed, and the discharged fuel is about 0.8% U-235, 1.2% plutonium and 0.2% other actinides, for a "fissile content" of 2.2%. Reprocessing can only recover about 44% more usable energy content that the fuel already has provided. If you are thinking of the U-238, it is not fissile, but must be bred further to make it fissile. We can obtain U-238 far more cheaply and easily, if we need it, by simply converting the millions of tons of depleted uranium currently in storage into breeding fuel element.

Sixth, reprocessing is very expensive. Make that "VERY expensive". The cost of the fissile material produced is much higher than enriching natural uranium, and every aspect of fuel fabrication and handling is much more expensive due to it being "hot" from the beginning. The value of mixed oxide fuel on the market is less than zero. Utilities must be paid a subsidy to take it for free.

Seventh, a breeder reactor power economy cost much more than a conventional power reactor economy. As things now stand the high capital cost of conventional power reactors make them economically unattractive without some sort of construction mandate, or special economic support. A system that is much more expensive is a non-starter if the conventional power reactor problem is not solved in practice (see point two, above).

Eighth+ (yes, I have more points), but I am tired of typing.

Re:Utter Stupidity

[nojayuk]

Gas and coal are cheap and the waste from burning them can be dumped into the atmosphere and nobody cares enough to stop burning them since that would increase the price of electricity and cost jobs (see "War on Coal"). Nuclear reactors, including breeders are expensive to build and everyone is petrified of spent fuel from reactors because they've been fed bullshit and crappy movies about the effects of radiation ever since 1945.

Using up spent fuel in new-design reactors by reprocessing and other means will cost money and new uranium fuel is really cheap at the moment (current spot price for U3O8 yellowcake is $34.15 per lb) and it will remain cheap for another 50 years and more as more mining sources are developed and brought into production.

The Russian BN-800 reactor is designed to burn spent fuel and also plutonium from decommissioned nuclear weapons but it's quite experimental and it will be a while before more reactors like it are built. The fuel for it still needs to be processed and specially fabricated, it can't just take used fuel pellets and this adds to the expected cost of operations.

Some countries such as Russia do reprocess spent fuel but that only concentrates the unusable isotopes that are actually waste and they still need to be dealt with, probably by deep geological burial. There doesn't seem to be any real problem with this idea but it gets a lot of attention from the panic merchants with the 100,000 year figure being thrown about a lot although that's quite arbitrary considering the environmental radiation sources already present around us naturally which do not emanate from the nuclear power industry.

Clarification

[PuddleBoy]

I believe what they mean is "concrete" rather than "cement".

Cement is a powder that is one component of concrete;

https://en.wikipedia.org/wiki/Cement

Together with sand, water, and aggregate (rock) they undergo a chemical reaction (when mixed) to form concrete. Changing the quality, component ratio and admixtures of concrete can dramatically change various characteristics like strength, set time, resistance to water pressure, etc. I can remember seeing concrete that was very dark (almost black-ish) in color. I was told it contained a lot of lead for use in radioactivity shielding.

Just sayin'

Re:Clarification

[wbr1]

Thanks for the concrete example. It really cemented things in my mind.

Re:Keep it close

[AJWM]

Er, assuming that was a serious question...

100,000 years is ten half-lives (for a 10,000 half life). The amount of the original material left would be (1/2)^10, or a mere 1/1024th the amount of material.

As far as the amount of (useful) energy left, that depends on what the original material decays into, vs what it was originally.

Re:Why 100,000 years

[careysub]

The 100,000 years thing is a scam meant to make the nuclear waste problem look intractable. LONG before that, the "waste" will be no more radioactive than natural rocks laying out in the desert in the U.S.

Not quite. Unless the actinides have been removed by reprocessing the spent fuel does not return to the same level as ore for a few hundred thousand years. The period chosen: 100,000 years is about right - not quite long enough to reach that point, but pretty good. The legacy waste they are dealing with contains actinides and is a nightmare to try reprocess due to its non-standard composition.

Imagining that all waste problems are really that of disposing of nearly non-existent reprocessed fuel waste with all actinides removed is silly. They are dealing with real waste that really needs disposal, not hypothetical types of waste.

BTW: the (quasi*) natural rocks laying out in the desert (tailings) are a significant waste problem since they have been removed from their stable geological context.

*They have been physically and chemically altered.

Re: Keep it close

[naughtynaughty]

All you need to know about Robert Schoch is that he believes in telekinesis and the paranormal.

Re:Keep it close

[Firethorn]

What comes out will be, without any processing really, be valuable reactor fuel. With some processing it can be made into a lot of valuable things, including the reactor fuel.

You're still going to have to process it to get reactor fuel. The important thing is that it's the radioactivity that makes reprocessing used fuel rods expensive, because said radioactivity tends to contaminate things.

If you store the used rods in a reactor pool for ~30 years, then in an above ground cask for another 30-60, as you say, the radioactivity is a tiny fraction of what it used to be. That means that it doesn't contaminate things nearly as much, thus will be something like an order of magnitude easier/cheaper to reprocess. You stuff the non-useful radioactives, and other materials you can't be bothered to separate, into another cask.