A matter of Waste: Latest in the SACOME #nuclear series

This is the fourth in the series of six articles on nuclear being publishing the journal of the South Australian Chamber of Mines and Energy. Our topic this time was radioactive waste in the context of a potential future Australian nuclear power industry. This article is co-authored with Barry Brook.

As before, please be mindful that word limits for print publications are always tough when you are tackling topics that require a bit of context, understanding and comparison, so if you are concerned that anything received brief treatment, the comment thread is yours.

In the big hitting concerns about nuclear power, long-lived radioactive waste may just be the most powerful in the public eye. But the fear-laden awareness of long-lived radioactive waste belies many of the realities of its management.

The best start for responsible management of any hazardous waste is to capture and contain it at the source. Nuclear power does this. Fossil fuels do not. The combustion of coal and other fossil fuels produces toxic fly ash, mercury, radioisotopes, nitrates and sulphates, and of course, huge amounts of carbon dioxide – globally, almost 30 billion tonnes each year. Fossil fuel is both a huge short-term health problem and the recipe for a long-term climate breakdown. Already, nuclear is way out in front.

Secondly, radioactive waste is perceived as complex. This is far from the truth. Radioactive material is one of the most predictable, easily monitored and best understood forms of waste. We know what it does, and how it does it, forever, and we manage it accordingly. Imagine a very loud noise source that you cannot turn off, that is very, very slowly getting quieter. Stand too close for too long and you will get an injury or even go deaf. How would you manage such a thing? Contain it in dense material, put distance between it and you, and let it quieten down. That is what happens for radioactive material in long-term storage, and it is very secure. The material in Dry Cask Storage at Fukushima bore the full brunt of the tsunamis, with no damage. The image of the leaky, rusty barrel being stuffed into a tree by Mr Burns is, quite appropriately, a joke.

The Simpsons. Not actually real.

Thirdly, the quantities in question are relatively very small. Australia produces (and somehow manages) around 1.1 million tons of hazardous waste every single year. A large-scale 25 GW nuclear power industry would add a mere 750 tons, taking up just 250 m3 (six-and-a-half standard shipping containers). But of course that doesn’t do it justice. This small quantity of contained waste would be displacing vast quantities of uncontained pollutants from fossil fuels; toxins and other unwanted by products that we have simply come to accept as the cost of reliable energy. The quantities for nuclear fission are so manageable that new reactor designs include a facility to hold all of the waste for the 60 year life of the plant, right there on site.

Babcock and Wilcox mPower SMR: The design is receiving a lot of very favourable attention. All waste is to be stored on site, underground, for the life of the plant

Still, a problem remains. We must babysit the radioactive waste for tens or hundreds of millennia. For instance, plutonium produced in nuclear reactors has a half-life of 24,100 years, meaning you have to wait a few hundred thousand years for it to lose most of its radioactivity. Although storage in deep, geologically stable repositories is technically possible, the idea of bequeathing future generations this responsibility leaves many people understandably uncomfortable.

There is, however, a much better option: consume the long-lived waste, and in so doing, generate huge amounts of zero-carbon electricity.  This can be done in Fast Reactors.

Plutonium and other ‘transuranics’ (elements heavier than uranium, such as neptunium, curium and americium – also called ‘actinides’) – are the substances responsible for the long-lived radioactivity of nuclear waste. It makes up about 2% of the spent fuel from current light water reactors. About 93% is uranium. The uranium is almost entirely the more plentiful, heavier and less-radioactive isotope U-238 which, unlike the rarer U-235, is mostly left unused in today’s commercial reactors. The Fast Reactors are able to consume it all, as well as all the plutonium and other transuranics, converting them into energy. That increases the energy density of uranium about 150 times.

Schematic of a Sodium-cooled Fast Reactor. Pair it with a compact on-site pyro-processing facility and you have the Integral Fast Reactor. 100% of waste in, less than 1% ever comes out again.

What’s left behind after multiple recycles are the ‘fission products’, about 5 % of the original (once-through) waste, which are the lighter elements created when the actinides are split apart. This is the ‘real’ nuclear waste.

The fission products need to be managed for about 300 years, after which time they’ve lost 99.9% of their original potency. To safely take them to this point, the fission products can be ‘vitrified’ (entombed within a highly durable glass-like matrix), or encapsulated within the Australian-designed ‘synroc’. This highlights another huge plus for the future of nuclear power. Not only can all of the world’s stockpile of spent nuclear fuel be consumed in Fast Reactors to produce copious amounts of zero-carbon energy, but what remains is a comparative cinch to take care of.

So nuclear waste stops being a major headache, and turns into an asset. An incredibly valuable asset, as it turns out. In the US alone, there is 10 times more energy in already-mined depleted uranium (about 700,000 tonnes) and spent nuclear fuel, just sitting there in stockpiles, than there is coal in the ground. This is a multi-trillion dollar, zero-carbon energy resource, waiting to be harnessed.

To recap then: waste from nuclear reactors is tiny in volume and fully contained at the source. It is well understood, and its safe management is relatively straightforward. By producing it, we would displace the vast uncontained toxic pollution from our fossil-fuel driven energy production, and take our most decisive step to resolving climate change. Within decades, it will be reused to produce yet more vast quantities of zero-carbon energy, leaving a tiny fraction of much shorter-lived waste behind. On the road to sustainability, this would be a great leap forward for Australia.

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8 thoughts on “A matter of Waste: Latest in the SACOME #nuclear series

  1. Marion Brook

    I don’t really have much time for comments at the moment (well not lucid time anyway), but that’s O.K. because I only need one word to cover this one.

    Excellent.

    Oh, and I love the ‘noise’ analogy.

    Reply
  2. wilful

    I can’t see the Chamber of MINES being terribly happy about the idea of putting them out of business.

    Seriously, for most audiences the idea that you can use all of the waste U and not have to mine any is a great idea, but for the minerals industry it is NOT good news.

    (and like they really care about sustainability)

    Reply
  3. Podargus

    The fossil fuel industry,from mining to end use,is the primary and most powerful opponent of nuclear energy.The anti-nuclear lobby is a mere tool of the fossil fuel sector but of course they can’t see that or,heaven forbid,admit it.
    As Ben says,the mining industry apart from coal,oil,gas and CSG,would have not the slightest concern about nuclear.In fact,in Australia I doubt whether the oil and gas industries would oppose nuclear as their product is assured of a market, for as long as the resource lasts,anyway.If the legislative barrier to nuclear was removed I think a lot of mining and energy companies would see it as a prospect for future profits and begin to invest in it but there will be a need for government assistance.

    The primary barrier to nuclear in Australia is political in its broadest sense. To surmount political problems in a democracy requires education of the electorate.This is the challenge.

    Reply
  4. gmhendo

    Well that’s great news – a way around the very important waste issue and a way of using the very considerable store of nuclear waste energy without even having to mine for it!
    One of my greatest fears for nuclear was the waste issue – if this scheme can be brought to reality nuclear starts to look very viable.
    There remains some hurdles though. The technology is way short of being proven.
    The costs of nuclear, is enormous, and it must still compete with other options such as solar, wind, geothermal and wave power that pose less risk and require less capital.
    Nuclear time-lines are also long, 10 – 15 years, maybe more, during which time more CO2 is belched out.
    The extraordinary cost of building the first reactor might ideally be shared amongst several countries, on the basis that if successful the technology be deployed globally.

    Reply
    1. Decarbonise SA Post author

      Yes, the positive implications of this technology are not short of staggering. Glad you grasped it so readily!!! A few reflections on your comment:

      The technology is way short of being proven.

      Actually, no. The technology was proven in 1994, then the program was killed by the Clinton administration in a fit of anti-nuclear fervour. You can read about this at a high level in “Prescription for the Planet” by Tom Blees, or in great detail by the designers of the system, Till and Chang in their just released book “Plentiful Energy” ($18 from Amazon). Where we are now is rather more the dawn of commercialisation, not technical proving.

      The costs of nuclear, is enormous, and it must still compete with other options such as solar, wind, geothermal and wave power that pose less risk and require less capital.

      Yeah, the up-front capital is high for sure, but not actually high compared to anything else that might ever provide zero carbon baseload. Two worthwhile links discussing this and http://bravenewclimate.com/2011/10/21/tcase15/ . Nuclear is, basically, the best value option we have available if zero-carbon baseload is the goal.

      Nuclear time-lines are also long, 10 – 15 years, maybe more, during which time more CO2 is belched out.

      Sadly true, especially when you are starting where Australia is, where the technology is actually, seriously, illegal! Not just frowned upon, actually against the law!!! I can only conclude that our task is to make sure those timeframes are legitimate, and not the result of vexatious action by opponents. The French experience of the 1980′s and the current Chinese experience suggest rapid deployment is certainly possible once the frameworks are prepared. It does not appear to be a fault of the technology per se.

      The extraordinary cost of building the first reactor might ideally be shared amongst several countries, on the basis that if successful the technology be deployed globally.

      Ha! Unless you have been a fly on the wall at some important meetings, you have without realising it outlined a big part of the approach being run by the Science Council for Global Initiatives! Good thinking. NB I agree first mover costs are always high, but for some very sound and simple reasons, IFR unit costs can be expected to be very low. They are much less complicated beasts than light water reactors, smaller, and suitable for factory roll out.

      Welcome to the blog, please have a good look around and get in touch if you have any questions.

      Reply
  5. John Newlands

    ARPANSA’s indoor radon map for parts of Australia is interesting. After opening Google Earth download the kmz file from http://www.arpansa.gov.au/radiationprotection/factsheets/is_RadonMap.cfm
    Clicking on a placemark gives radioactivity data. My guess is indoor radiation is a function of both soil and building materials. For example minor uranium occurrence Houghton in the Adelaide Hills gives 36 Becquerels per cubic metre and 1.1 mSv/y average of two buildings. Walkerville for example gives 41 Bq/m3 and again 1.1 mSv/y. If natural background radiation from all sources is about 2.4 mSv/y world wide then Adelaide region indoor radiation is about half that. Possible hotspots like Roxby Downs were outside the survey area. Check it out.

    Reply

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