It is proposed to build the world's biggest tidal-farm off the north of Scotland. While this sounds worthily "green" and "renewable", an independent nuclear consultant Dr John Large has warned that the cables that will need to be run along the seabed may disturb thousands of radioactive particles that originated from the Dounreay nuclear power plant, the world's first commercial fast-breeder facility which opened in 1955, its first reactor achieving criticality in 1958.
Since the principle of a fast breeder reactor is that it converts the majority isotope of uranium (238) to plutonium-239, there have been worries voiced before when plutonium containing particles were washed-up on the neighbouring beaches to Dounreay. It is an odd irony that the potential stirring-up of that old nuclear legacy and its attendant putative health-problems, might be used as a reason not to build the giant renewable wave-farm, and to extend the use of nuclear power instead, albeit of the fission-reactor kind that produces less plutonium in its operation.
Interestingly, one third of the power output from a fission reactor is derived from the fission of plutonium that is produced "accidentally" by breeding from uranium-238, since only around 3.5% of the uranium that is fabricated into nuclear fuel rods is actually the fissile uranium-235 (the rest being uranium-238), enriched from the natural level of 0.7% which is insufficient to fuel a light water reactor, although it can be used per se in heavy water reactors.
The particles are about the size of grains of sand and have leaked from the Dounreay facility, ten miles away. They are capable of burning holes in the skin, should someone come into contact with them, where they can cause ulceration and cancers. These particles, thousands in number, are thought to have leaked since the 1960s from a disused waste shaft which projects some 600 metres out to sea. The nuclear plant was closed in 1994.
The wave-power scheme would involve running hundreds of underwater tidal turbines, linked by cables buried around two meters in depth to an electrical sub-station on the Caithness mainland. By harnessing the tides of the Pentland Firth, it is estimated that enough electricity could be produced to run a city the size of Edinburgh.
 "SNP wave farm could generate "nuclear threat". http://www.timesonline.co.uk/tol/news/uk/scotland/article4881909.ece