Topic Title: Progress on approaches to the management of separated plutonium
Topic Summary: No progress at all in my opinion
Created On: 21 January 2014 04:34 PM
Status: Post and Reply
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21 January 2014 04:34 PM
NDA Position Paper
I should point out for the unwary that this document refers to MOX in vague terms. What the NDA mean by MOX is Uranium-Plutonium MOX not Thorium-Plutonium MOX.
The NDA's position is still that Thorium-Plutonium MOX is never going to be a credible option on the timescales over which it operates (tens to hundreds of years)
What I hate about government consultations is that they take an instantaneous snapshot of opinion? This snapshot can be wrong or premature and dominated by incumbents whose business models are failing. They take a snapshot without properly encouraging participation form potential new entrants.
Government then work with these snapshots unproductively for many years stonewalling all other enquiries until they eventually find that their original consultation has been left behind by events.
Then they start a new consultation.
Why not state a price to get rid of plutonium per kg transmuted, that applies to all private sector schemes?
If the NDA gives 100 kg of plutonium and they are handed back waste containing 1 kg of plutonium, then the net reduction is 99 kg.
If the price of transmuting long lived plutonium actinide waste is set at £6000 per kg and the cost for taking it back is set at £12,000 per kg
Then the NDA pays the third party company 99 * £6000 = £594,000 and the third party company pays the NDA 1 * £12,000 = £12,000
- a net payment of £582,000
However if the third party company only reduces the plutonium by two thirds then they make no money from the transaction, just from the energy released in burning plutonium.
Therefore the process must be a lot better than 66% efficient in transmuting plutonium and other long lived actinides for the third party company to make significant money from this transaction.
The numbers are just guesses and can be changed as is found appropriate.
This way what can be done physically with the plutonium stockpile becomes transparent, above board and measurable economically. Storing long lived nuclear waste is costly and there should be an economic premium put on methods that can get rid of it.
At the moment my distinct impression is that the NDA is an organisation without proper leadership and direction. I suppose I am just biased because I have been stonewalled in regards to my Wlfa conversation initiative.
21 January 2014 06:58 PM
I think the NDA has to have a better business model and that business model has to come from how they should best partition and store UK's radioactive nuclear waste.
Over 90% of direct fission product waste will be less radioactive than some common naturally occurring rocks, such as granite etc, in 300 to 500 years.
Lets say the cost of storing fission product waste works out at a cost of £4000 per kg for up to 500 years of storage.
As 1 tonne of fission products arises from 1 GW year of electricity generation, this waste arises from £482 million of electricity sales at market rates of £55 per MWh. Storage of 1 tonne of fission product waste for 500 years above ground costs £4 million say.
However the cost of storing longer lived waste is many times this, as it has to be stored for thousands of years underground. Lets say 10 times this for the sake of argument, say £40,000 per kg
Therefore if the NDA can afford to pay a private sector company something to transmute waste that will otherwise cost it £40,000 per kg to store for thousands of years.
Therefore the NDA should charge generators for storing the nuclear spent fuel waste based on:
1) initial storage of unpartitioned waste if not undertaken by the waste producer.
2) handling and partition costs per kg of waste
3) the length of time each spent fuel partition has to be stored before it is less radioactive than natually occurring granite rock (per unit mass)
Lets say it costs £1000 per kg of actual spent fuel to partition into
1) Uranium and Thorium to be recycled or stored as recyclable waste
2) Fission product waste with a half life less than 30 years
3) Fission product waste with a half life greater than 30 years
4) Plutonium and other long lived actinide mixed waste
1) results in a small net income
2) requires a payment of £4,000 per kg for storage over ground
3 and 4) requires a payment of £40,000 per kg for storage underground
Because the storage charges for 4) are large compared with other partitions, other options must be considered. Separation of Plutonium for use in products like Uranium or Thorium MOX might be justified as a result.
If the NDA calculate that vitrifying the plutonium and long lived actinide waste and storing it underground is the default option, then the round trip commercial cost of purifying, using and transmuting plutonium and then reporcessing the associated waste must be cheaper than this to be considered worthwhile.
The problem is that the NDA may have extra costs associated with taking back plutonium and long lived actinide waste that private sector players fail to fission and burn-up. Therefore they should charge a price for taking back plutonium and long lived actinide waste that compensates them fairly for this.
If we start assembling a sensible business model for the NDA, then the question of the maximum allowed enrichment of uranium comes into play as an economic variable and not just a non-proliferation issue.
As a molten salt reactor operator I may want to use a denatured start-up mixture of high-enriched uranium and thorium fuel, so that the breeding ratio of the reactor can just exceed one, as Uranium-235 is gradually replaced by Uranium-233. [a denatured reactor with mostly thorium make up, but also a little depleted or natural uranium make up to keep uranium enrichment below a certain level within the fuel mix say 50% or 60%]
Hopefully with such a reactor the uranium-238 fraction is low enough that plutonium and higher actinide waste is kept to a minimum and thus NDA waste charges kept reasonably low.
In return for using high enriched uranium fuels mixed in with thorium the regulatory authorities may say
a) no on-site uranium separation from the thoriun fuel matrix allowed
b) depleted uranium or natural uranium make up to keep the uranium enrichment within the fuel matrix below a certain upper maximum.
c) all waste is returned to a licensed operator for uranium to be separated for reuse and new thorium-uranium fuel batches made up, by splitting off the fission product waste and long lived actinide waste
Increasing allowed uranium enrichment where it is dissolved in a thorium fuel matrix, seems to me to be a rational way to reduce costs in civillian nuclear reactors. I think we should further investigate the minimum level of uranium enrichment required in a molten salt thorium reactor before the breeding ratio starts to dip below one.
The regulatory authorities could then make an assessment based on the state of the art in regards to detection equipment, whether or not people with malign intent could feasibly prepare highly enriched uranium (including a Uranium-232 component) and move this stuff around without being detected at ports of entry or via satellite. e.g. the amount of lead and/or depleted uranium that would be needed to screen the enriched uranium containing Uranium-232 from detection devices and this would be physically possible in practice.
To me this would be progress.
21 January 2014 07:03 PM
The end of the second but last sentence should read.
... and whether this would be physically possible in practice.
Progress on approaches to the management of separated plutonium
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