Overseas fuel
Part of the site at Dounreay was devoted to the supply and recycling of specialist nuclear fuel.
A series of chemical plants, known as the Fuel Cycle Area, serviced research reactors in the UK and more than a dozen countries worldwide as well as looking after the needs of Dounreay's three reactors.
These plants recycled used fuel, dissolving the elements in acid and separating the re-usable nuclear materials from the radioactive waste. The recovered nuclear material then could be used again as new fuel.
Between 1958 and its closure in 1996, the materials test reactor reprocessing plant alone dissolved almost 13,000 fuel elements, of which almost 4000 came from reactors in Africa, Asia, Australia and Europe.
In 1976, the UK Government decided the operators of these reactors should in future take back their radioactive waste as well as the recovered materials.
Dounreay concentrated on servicing UK reactors after 1976.
In the late 1980s, when the UK Government decided to close down the fast reactor programme, UKAEA re-opened its chemical plants to overseas reactors. Its objective was to raise money to offset the cost of decommissioning the site's fast reactors.
Dounreay signed a series of new contracts that resulted in spent fuel arriving from Belgium, Denmark (of Italian origin), Germany, the Netherlands, Spain, France and Australia for storage and reprocessing.
The waste to be returned under these contracts was estimated to be equivalent to less than 500 of the standard 500-litre drums used at Dounreay for the conditioning of intermediate-level waste. This represents two per cent of the UK-owned waste at Dounreay. None of this waste has been returned to date.
By 1996, when a breakdown occurred in one of the chemical plants, more than 800 elements from overseas had been reprocessed, with less than a tonne of spent fuel from Belgium, Denmark, Germany, the Netherlands, Spain and France still to be done.
In 1998, UKAEA decided not to take in any new spent fuel (although an exception was made shortly afterwards, on the grounds of international security, for the arrival of a small amount of spent fuel airlifted from Georgia by the US Government.)
In 2001, following public consultation, the UK Government decided not to repair the chemical plant.
It is now being cleaned out and dismantled along with the other plants in the Fuel Cycle Area. One of these - the fuel fabrication plant - has already been demolished.
Today, a small but important part of the site closure programme is reaching agreements with historic customers to close their contracts.This needs to be done in a way that is compliant with UK Government policy about the return of foreign waste.
Dounreay no longer has plants to recycle the remaining spent fuel and the contracts do not allow it to be returned in its untreated form because the owners do not have specialist treatment facilities of their own.
It has been agreed in principle instead to send each customer an amount of new fuel and waste from UK stocks, equivalent to what would have been produced if the fuel had been reprocessed, with the UK retaining the spent fuel. The detailed arrangements are now the subject of negotiations. This is known as "advance allocation".
The spent fuel from Spain that Dounreay wasn't able to reprocess has been transferred to a third country.
In addition to spent fuel, the site also had contracts in place for unirradiated fuel belonging to other countries. Similarly, with the facilities to carry out work on this fuel now gone, the site is negotiating alternative arrangements to close these contracts, subject to a Government consultation document.
INS, a subsidiary of the NDA, is now responsible for concluding these contracts. See: Dounreay hands over old fuel contracts
Spent fuel was dissolved and separated in a series of vessels in the materials test reactor fuel reprocessing plant
Spent fuel arrived at Dounreay from all over the world when the site operated chemical plants to recycle nuclear materials
The recovered uranium metal was reworked in the fuel fabrication plant to create precisely-engineered fuel elements
Uranium recovered from the spent fuel reprocessing plant was turned into new metal in an adjoining facility
Demolition in 2008 of the fuel fabrication plant
Fuel was manufactured in the D1202 fabrication plant
Workers decommissioning the former materials test reactor reprocessing plant
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