Cleaning Up and Costs
Although the UKAEA kept no precise accounts for building and running Dounreay, it is known to have cost several billion pounds. Now a further £2.5 billion will be spent returning the site to its pre-nuclear condition, leaving only a vault, covered with grass, to hold low-level nuclear waste while high-level waste will probably be shipped to a central UK nuclear store yet to be approved. ‘An immense amount of money was spent here,’ admitted Steve Beckitt, a senior Dounreay project manager.
Note that although the cost of the cleanup was given as £2.5 billion ($3.9 billion, € 2.9 billion) in the late oughts, the current (2013) contract for decommissioning Dounreay is reported at £1.6 billion ($2.5 billion, € 1.86 billion). The cost and difficulty of the decommissioning effort are increased by the ad hoc nature of Dounreay’s waste disposal in the past, and the lack of documentation. For example, once the plutonium building in the criticality test lab was declared unsafe and uncleanable in 1967, it was locked and left untended for 20 years. But it was also used to store “other radioactive junk” during the 70s and 80s, of which no record seems to have been kept.
Similarly, unaccounted-for reactive material including Uranium 235 has been found during the current decommissioning process by opening and examining containers that had been sealed under Dounreay’s original management:
More than 200 drums filled with waste produced during past operations at the plant have been opened up and their contents inspected before being repacked for long-term storage.
Decommissioning engineer Bob McKiddie said equipment being used to detect what was inside the drums was far more accurate than anything available when the containers were originally filled.
Mr McKiddie said: “We had suspected that the historical results had under-estimated the uranium content in a number of waste items.
“The repackaging work has resulted in an overall gain in the amount of uranium declared.
“The figures from the repackaging work show that material previously considered ‘lost’ was in fact safely packaged as waste.”
The champion, of course, for undocumented and randomly accumulated waste is the shaft:
Steve Efemey, who is in charge of the retrieval and treatment phase, said [of the waste shaft] … “We don’t know exactly what’s down there or what condition it is in as there are different degrees of degradation. That’s the challenge.
“The worst-case scenario is that the sodium drums are still intact. But that is unlikely after 50 years and 1500 tonnes of waste on top of them.”
In the “Other Problems” section, we noted the presence of 50 tons of liquid metal coolant inside the giant sphere. In a major triumph, 1500 tons of liquid metal coolant from the second Dounreay reactor has been decontaminated, but much remains from the original reactor:
The reactor has been de-fuelled apart from one stuck experimental fuel assembly and 977 breeder elements, at least 10 per cent of which are jammed or heavily damaged by earlier de-fuelling attempts. The secondary NaK [the liquid metal coolant] has been removed but the primary NaK is intact, with high levels of radioactive contamination.
The radioactive NaK and associated nine kilometres of reactor pipe work represent one of the most significant hazards at Dounreay.
The cleanup of the radioactive reactor rod shavings that were flushed into the ocean, although the major environmental contamination at this point, is projected to be a relatively minor component of the cleanup costs, at £18-25 million ($28-39 million) of which £800,000 has gone to the design and construction of a remotely-operated underwater robotic vehicle that travels along the sea floor, searching for and collecting the radioactive particles.
However, the Scottish Environmental Protection Agency (SEPA) has accused the UKAEA of vastly misrepresenting the number of particles, and essentially merely putting on a show with its underwater cleanup operation.
 “Robots scour sea for atomic waste,” The Observer, May 24, 2008. http://www.theguardian.com/environment/2008/may/25/pollution.conservation
 “Experimental criticality laboratory”, Dounreay Site Restoration Ltd. http://www.dounreay.com/decommissioning/experimental-criticality-laboratory
 “’Lost’ radioactive material found”, BBC News, December 4, 2009. http://news.bbc.co.uk/2/hi/uk_news/scotland/highlands_and_islands/8393783.stm
 “No-one knows what is left in the Dounreay waste shaft”, The Herald, January 25 2007. http://web.archive.org/web/20081007172440/http://www.theherald.co.uk/news/news/display.var.1145249.0.0.php
 “Milestone in hazard reduction as liquid metal is destroyed”, Dounreay Site Restoration Ltd. http://www.dounreay.com/news/2008-08-18/milestone-in-hazard-reduction-as-liquid-metal-is-destroyed
 “DFR Overview”, Dounreay Site Restoration Ltd. http://www.dounreay.com/decommissioning/dounreay-fast-reactor/dfr-overview
 “Robot collects 300 radioactive particles from Dounreay seabed (only 400 to go)”, The Scotsman, October 1, 2010. http://www.scotsman.com/news/robot-collects-300-radioactive-particles-from-dounreay-seabed-only-400-to-go-1-823186
 “Watchdog hits at Dounreay’s false reporting”, Mark Macaskill, The Sunday Times, April 16, 2006. http://www.thesundaytimes.co.uk/sto/news/uk_news/article199634.ece