The real nuclear waste consists of fission products. The highly radioactive but relatively short lived material formed by splitting (fissioning) uranium and plutonium. The amount of this material is very, very small. Only about 4% of the used (spent) fuel removed from a nuclear reactor. And it has a half life which means that after only 100 to 300 years it is less radioactive than the uranium which was dug out of the ground in the first place. It is vitrified (formed into glass) and put in a stainless steel containers about the size of a milk churns and can be stored safely in relatively small surface level vaults for 100 years until it is about the same level of activity as naturally occurring uranium. If people would rather see it put into an underground repository so be it. But it is still perfectly manageable and infinitely less than the nine billion tonnes of carbon dioxide spewed into the atmosphere by burning fossil fuels.

So what is worrying people? It is the small quantity of plutonium which is formed from uranium-238 in any reactor. The half life of this runs into thousands or tens of thousands of years. This is still less than the millions and tens of millions of years of the natural radioactive uranium from which it was formed but it is a rather long time for surface storage. So why not recycle it in a nuclear reactor to produce more energy? That is what we do when we reprocess the used (spent) fuel from our present day reactors and recycle the mixed uranium/plutonium (MOX) fuel in the same reactors. We also get the benefit of 25 to 30% more energy which can not be a bad thing.

But we could do better than this. First, by recycling in a fast reactor which gives about sixty times as much energy. That’s a heck of a lot of energy and also helps to dispose of depleted uranium from enrichment plants for which the only other use is in armour piercing shells. We actually have enough depleted uranium already in store in this country to equal the energy content of our coal resources.

There are various new fourth generation of reactors which are still at the early research stage but which offer better prospect for recycle. It should be possible to do everything including reprocessing in one reactor burning the plutonium as and where it is formed. Finally this leaves just the small amount of fission product waste and perhaps a trace of plutonium.

Why then is not everybody going the recycling route? An awful lot of nonsense was produced by some advisors to President Carter and President Ford back in the 1970’s. This is still proliferated with articles on recycle on the internet. Basically they are saying that there is a weapons proliferation risk associated with what they call the “plutonium economy”. A huge, two year, international evaluation of the fuel cycle options (the International Nuclear Fuel Cycle Evaluation, INFCE) was carried out under the management of the International Atomic Energy Agency (IAEA) and concluded that recycle could be just as safe as the once through cycle. But the US still carried on opposing it. Other countries, in particular France, persisted with recycle and demonstrated that it could be reasonable economical and that it is getting more economical with rising oil and gas prices.

So there you are: you either believe a lot of environmentalist and have a nuclear waste problem or you believe in recycle.

We apologize for some similarity of subject matter in these first two reports. They were written by different people and present different facts and figures. There was insufficient time to consolidate the two.


Two redundant words
The ‘killer’ argument often posed by those opposed to nuclear power, after perhaps reluctantly admitting that there could be some advantages, is “What about the waste?” with the suggestion that there would be large quantities of spent fuel to be disposed of, that would remain radioactive for hundreds of thousands of years or more, and could never be safely contained with complete certainty – posing a serious threat to future generations to which there was no solution. These views can now be seen as outdated. The thrust of the question is reversed to become “What waste? A greater part of the so-called waste is the spent (used) nuclear fuel elements discharged from the reactors after some four of five years life as they lose reactivity with the build up of neutron capturing fission products. Rather than waste this is a valuable energy source that can be recycled. This spent fuel contains about 95% uranium, 1% plutonium, and 5% of fission products of which 2% are the minor actinides (americium, curium, neptunium).

The total world accumulated quantity of nuclear waste after some 40-50 years of operations at the beginning of 2004 is given as 268 000 tonnes of Heavy

Metal of which 90 000 tonnes has been reprocessed. A minute quantity compared to the many millions of tonnes of waste material, including carbon dioxide, discharged in generating electricity by burning coal.

Annual production by 2010 is estimated at 11 500 tonnes HM per year and by 2020 the total accumulated production from the presently operating reactors is expected to increase to 445 000 tonnes. The present world nominal commercial reprocessing capacity is 5950 tonnes of which almost half, 2400 tonnes is in the two plants at Sellafield – B205 reprocessing Magnox fuel which is expected to close by 2012 and THORP processing LWR and AGR fuel (due to operating problems the actual throughput at THORP is much less than the nominal capacity).

The cumulative quantity of fuel that has been reprocessed at Sellafield is 42 000 tonnes of Magnox fuel in B205 and 5 800 tonnes of AGR and LWR fuel in THORP – about half of the world total. (IAEA Techdoc 1587 Spent Fuel Reprocessing Options).

There are three possible options for dealing with nuclear waste. The first is Direct Disposal – a once-through throw away fuel cycle. With sluggish growth in nuclear energy generation added to mounting concerns about nuclear proliferation some countries have turned to the once-through fuel cycle policy, declaring spent fuel as waste. As about one-third of the global spent fuel inventory has been reprocessed the remainder is yet to be disposed of or processed. The consequence has been a continuing increase in the accumulation of spent fuel in various modes of interim storage, although Finland, Sweden and the US are now building deep underground repositories for spent fuel. Geological storage was also, after five years of study, the first recommendation of CoRWM (Committee on Radioactive Waste Management). The second option is a Storage and Postponed Decision – or wait and see do nothing – which CoRWM also proposed as a second fallback position; and third the Reprocessing and Recycling or closed fuel cycle option which recovers and recycles the so-called waste as a valuable energy resource.    

When recovered by reprocessing the spent fuel some of the uranium and plutonium can be recycled as MOX (mixed uranium/plutonium oxides) fuel in present Light Water reactors (LWRs). This avoids wastage of uranium, a valuable and ultimately limited resource, saving up to 30% of the natural uranium that would otherwise be required, and eliminating the enrichment costs to produce the new fuel. This is already in hand. MOX fuel is becoming more widely used and is licensed for some 40 reactors in Europe as well as in Japan and the US. Present operating LWR reactors can take up to 33-50% of their fuel as MOX while the new European Pressurized Water Reactor (EPR) being built in Finland and France could use 100% of MOX. MOX provides about 2% of the new fuel used today, and this proportion is expected to rise to 5% by 2010. MOX also provides a means of burning weapons-grade plutonium from military stockpiles which are now being run down.

A plant for this purpose with a capacity of 3.5 tonnes of plutonium a year is now under construction in the US.

Reprocessing seven or eight uranium oxide fuel assemblies could give one MOX element together with some high level waste but with a 35% reduction in the volume, mass and cost of waste disposal. Spent MOX fuel can in turn be reprocessed but a more favoured option is to store this material for use in the Generation IV advanced burner reactors now being developed by the international partnerships GNEP and the Generation IV International Forum (GIF).

Proposals for the development and introduction of these new reactor systems include further advances in the reprocessing of spent fuel. The existing reprocessing plants separate plutonium and uranium and leave the minor actinides with the rest of the fission products. Initially the first of these plants were intended to produce plutonium for military weapons and this legacy has tarnished the reputation of reprocessing and it is now a focus for opponents of nuclear power. For this reason even the use of MOX fuel is opposed as promoting a ‘plutonium economy’ with claims that it not only encourages nuclear proliferation but is also uneconomic – a charge that is obviously contrary to the choice of MOX fuels by an increasing number of utilities. This opposition is indeed surprising – swords into ploughshares and the recycling of wastes are arguments that should have a strong appeal to environmentalists.

Now however the Generation IV reactors under development will be able to burn plutonium and the minor actinides. These can then be extracted from the spent fuel together with the uranium and plutonium. The plutonium product in this state is unusable for weapon purposes. But there are further advantages as almost all the spent fuel will become available for reuse. This not only drastically reduces the amount of waste to be sent for storage, but all the long life radioactive elements (uranium, plutonium and the actinides) will have been removed for recycling leaving only the few percent of fission products to be disposed of as waste. Most of these are stable, and those which are radioactive have lives of only a few hundred years rather than the thousands and tens of thousands of years of the heat generating uranium, plutonium, and actinides. Since the capacity of a spent fuel repository is determined by the heat content of the waste rather than its volume not only will the capacity of a repository for reprocessed waste have been increased, but the radiotoxicity of the waste itself will have decayed after about 500 years thus simplifying the disposal technology and the costs of building and operating the repository itself. It is hoped that this will reduce the opposition to disposal of waste as any underground facilities will not only be much smaller but can be designed for a life of only a few hundred years.

There is now a considerable development effort on devising the new and improved reprocessing processes notably in France, Japan, India, Korea, Russia, and the US (regrettably the UK, even though it still is the world’s largest reprocessor, is no longer able to contribute). Work on the new reprocessing technologies is following two routes distinguished between aqueous processes and pyrometallurgical processes, a dry route. The “aqueous route” processes builds on the existing mature technology of the Purex process (solvent extraction with tributyl phosphate) and can ensure very high separation performance (recycled material recovery yield and purification factor) while generating only small quantities of technological waste. A number of variants are at an advanced stage of development in several countries under development including France and Japan. In the main alternative pyrometallurgical processes, in which the spent fuel elements are dissolved in a bath of molten salts (chlorides, fluorides, etc.) at high temperature (several hundred degrees Celsius), the desired elements are separated by techniques such as liquid metal extraction, electrolysis or selective precipitation – all classic techniques, but implemented under severe conditions. These processes have raised interest mainly because of their ability to dissolve refractory compounds as for the fuel from high temperature gas-cooled reactors. The low radiation sensitivity of the inorganic salts used should make them suitable for “online” reprocessing of fuel immediately after unloading, and they offer a low criticality risk with the absence of water. This technology would also be the obvious choice for the online reprocessing of liquid fuel from molten salt reactors. Work in Russia and the US is up to pilot plant level for demonstration tests. Other alternatives are the reductive extraction in molten fluorides by liquid aluminum (France) and fluoride volatility processes (the former Czechoslovakia and Russia), as well as electrolysis or liquid metal extraction.

What was waste can become a valuable energy resource. It is inconceivable that in a world where an ever-growing population seeks to use ever-increasing amounts of energy, and where the resource of fossil fuels, coal, oil and gas must eventually be exhausted we will continue to treat spent fuel as waste and throw away a valuable energy resource.

Reprocessing costs
The relative costs of reprocessing and direct disposal are a matter of controversy. Those opposed to the recovery of plutonium and its reuse claim that MOX fuel is uneconomic. In 1994 an OECD study suggested that given the uncertainties there was no significant cost difference between the prompt reprocessing and direct disposal options, especially with the varying conditions and restraints in different countries. At that time the total fuel cycle costs, including reprocessing, were put at 6.23 mills/kWh (with a range of 5, 17-7, 06 mills 6 mills/kWh); while on a comparable basis for the direct disposal alternative they were 5.46 mills/kWh (with a range of 4.28 - 6.30 mills/kWh). In the intervening 15 years the costs of natural uranium, its conversion and enrichment have increased considerably, while the costs of construction and operation of a deep geological repository are still far from certain. The conclusion is that other factors such as national strategy, reactor type, and public acceptance, in addition to the recycling objectives, will have a greater influence on the selection of a spent fuel management option. It is also the case that the cost of fuel for a nuclear reactor is only a minor component, accounting for less than 20% of the final generation cost, and of that 20% the spent fuel treatment costs, typically about one/third of the total fuel costs, contribute only about 5 to 7% to the final electricity generation cost.

The final evidence for the economic case for recycling must be in the increasing adoption of MOX fuel for many of the world’s reactors.

The greater promise of advanced reprocessing and the Generation IV reactor systems however is in the reduced plutonium proliferation risks; the almost complete elimination of waste as well as the reduction in its radiotoxicity; and a bountiful supply of nuclear fuel.


An energy future
The IAEA Techdoc report gives the world cumulative quantity of reprocessed spent fuel at the beginning of 2004 as some 90 000 tonnes heavy metal. Of this about 1 percent is plutonium – a quantity of 900 tonnes.

 For the UK the cumulative quantity of reprocessed fuel is given as 42 000 tonnes which would indicate a plutonium production of 420 tonnes. In its declaration to the IAEA the Government gives the stock of civil uniradiated plutonium, which has been extracted from spent fuel rods but not yet reintroduced into nuclear reactors as 105.2 tons with an additional 34 tonnes at civil reactor sites and reprocessing plants. (Does the difference between these figures relate to stocks of military plutonium?)

One tonne of plutonium used as MOX fuel contains the same amount of energy as two million tonnes of coal.

From the Techdoc figure if all of our 420 tonnes of separated plutonium were converted to MOX fuel this would be equivalent to 840 million tonnes of coal. It corresponds to almost 16 years of coal consumption at UK power stations which in 2007 burnt 53 million tonnes of coal to generate about one-third of the electricity supply.

The uranium from reprocessing, which typically contains a slightly higher concentration of U-235 than occurs in nature, can be reused as fuel after conversion and enrichment, if necessary. With the development of the Generation IV reactor systems using closed fuel cycles it will become possible to recycle all the uranium recovered in reprocessing. In 2004 this amounted to almost 90 000 tonnes in and is increasing every year. With almost 50 GWh of electricity that could be produced from one tonne of natural uranium, the potential world energy supply energy is almost unlimited.

Who will be recycling Eventually the energy situation will dictate and we will have to adopt recycle of nuclear fuel rather than the throw away cycle. But who is going to realise and act on this inevitability and actually do something positive. The signs are not exactly encouraging and we need a massive effort to counteract the negative views of environmental pressure groups which occupy much of the space under “spent fuel” on the internet. They argue it is too expensive and will result in weapons proliferation. Well ask the French if it is economic – they are the only ones recycling regularly at present and their reactors are producing 80% of the country’s electricity at the lowest cost in the world. And where are all these terrorist bomb makers? But this country is one of the most shameful because we have reprocessed lots of nuclear fuel to produce a stockpile of separated plutonium and we even have a plant to make it into MOX fuel. It has been estimated that there is enough to fuel five large reactors for their entire lifetime – that’s equivalent to about 90 000 wind generators. So why not start doing it at Sizewell B and for that matter in some of the Advanced Gas-cooled Reactors (AGRs) where it is possible if a little less economic? But no – British Energy working with outdated figures has set its face against any recycle. Will it help now that British Energy has been taken over by Electricite de France? The biggest problem is however the US. They have 104 reactor producing over 12 000 tonnes of used (spent) fuel a year and likely to go on doing so for the next twenty to thirty years with present license renewal. The trouble is that the utilities have already paid the government 1 mill for each kW of nuclear power that they have produced to fund the provision of a repository and take the spent fuel off their hands. That this programme has been severely delayed merely increases the utilities wish to see them get on with it. If all goes well – which it probably will not – they could start putting spent fuel in a Yucca Mountain repository as soon as 2012. It is stated that this should be retrievable for the first fifty years but who in reality will want to spend money getting it back once they have it off their hands.

The US will need to build a reprocessing plant for recycling their used fuel. Although Britain, France and Japan could help them out with batches for testing and validation of MOX fuel they will eventually need their own reprocessing plant with a capacity of 12 000 tonnes per year. The building of such a plant will be a major project costing tens of billions of dollars and will be fiercely opposed at every move.

Healthy workers A new report from the Health Protection Agency studies the cancer and mortality risks of workers in the radiation industry using data from the National Registry for Radiation Workers (NRRW). To obtain more precise information on the risks of occupational radiation exposure than in prrevious studies the NRRW cohort has now been expanded to include about another 50 000 workers and the period of follow-up has been extended by nine years, to the end of 2001.

Data on cancer registrations have also been included in the NRRW for the first time, together with mortality data. .The analysis shows that overall mortality was 81% of that expected for the general population of England and Wales, having allowed for the effects of age and gender while total cancer mortality was also reduced, being 84% of that in the general population.

These reductions are ascibed to a ‘healthy worker effect’ (HWE). Thisis said to be seen in many studies of workers, not only radiation workers, where it is believed to reflect factors associated with the recruitment and retention of persons in work.

To study the possible impact of radiation exposure on health whilst minimizing the impact of the HWE, rates of mortality and cancer incidence within the NRRW were analyzed according to workers' radiation dose, which was assessed through personal monitoring.

Mortality and incidence from both leukaemia excluding chronic lymphatic leukaemia (CLL) and the grouping of all cancers excluding leukaemia increased to a statistically significant extent with increasing radiation dose. These estimates of a trend in risk with dose are said to be similar to those for the Japanese atomic bomb survivors, with confidence ranges that excluded risks more than two to three times greater than the A-bomb values and also excluded the possibility of no raised risk. There was also some evidence of an increasing trend with dose in mortality from all circulatory diseases combined. But other studies of radiation workers have yielded mixed results and the NRRW finding may, at least partly, be due to confounding by smoking, although in contrast, both for mortality and incidence, the trend with radiation dose in cancers other than leukaemia was maintained after excluding lung cancer, so indicating that this trend is not an artifact due to smoking.

A separate study of cancer in the offspring of female radiation workers, to examine whether the offspring of radiation workers were at raised risk of childhood cancer, but the analysis of the new data did not show any association between childhood cancer and maternal preconception radiation work. This larger study does not support the earlier finding of a raised risk in the offspring of female radiation workers. However, when the original and new data were combined, a weak association was found between maternal radiation work during pregnancy and childhood cancer in offspring, although this was limited by the small number of cases.

These studies show that workers in the radiation industry are not significantly at risk. It might be argued that since, with a lower mortality rate, they live longer their cancer rates should be higher than average as cancer can be the ultimate killer of old age.


100 Watt not so bad

The sad demise of the 100 Watt bulb which is to be withdrawn from sale reveals a basic misunderstanding of what is going on. The incandescent bulb produces part of it power as light (20%) and part as heat (80%). In winter in a reasonably insulated room the heat contributes to warming. It is not much but it could make the European Union’s estimate of the saving to be made by banning incandescent lights a distinct over estimate. On the other hand a cold long life bulb does practically nothing to warm the place though it’s heat production – which comes out of the base – can pose problems in certain applications. Of course in the summer one does not need the heat but in summer one probably does not need as much light either.

We are not trying to stop the greater use long life energy saving bulbs which for lighting definitely offer some saving but at least we should keep the option open for some use of warm incandescent bulbs.