Dounreay mistakes admitted

06 February 2007

The UKAEA has pleaded guilty to four charges relating to the mismanagement of radioactive materials and waste at the former nuclear research site, Dounreay, Scotland. The UK clean-up group will be sentenced on 15 February.

One of the charges relates to unauthorised landfill disposal of radioactive materials between 1963 and 1975; And one to occasional failure to prevent the discharge of fragments of used nuclear fuel to sea between 1963 and 1984 - the Dounreay Particles. All charges were brought under the Radioactive Substances Act of 1960.

The court action was instigated by the Scottish Environmental Protection Agency (SEPA) after a lengthy investigation involving the interview of many current and former Dounreay staff. The initial aim of the investigation was to find the origin of the Dounreay Particles.

SEPA's chief executive, Campbell Gemmell, said: "UKAEA has cleaned up its act significantly and is making strenuous efforts to safely dismantle the Dounreay site, which is no easy job. As part of our comitment to better regulation we will support them in doing this, as we support other operators who are serious about the environment."

Staff failed to ensure the correct handling of radioactive materials, with some fragments entering surface drainage systems which led to the sea. Colin Punler, UKAEA's Dounreay Communications Manager explained one of the mistakes to WNN: On one occasion, water was being transferred to a fuel cooling pond for treatment through a pipe, when a road vehicle damaged that pipe and water back-syphoned onto a roadway. The Fire Brigade was involved in the immediate clean-up of the accident and some materials from the water were hosed into surface drains, while others were picked up from the ground and wrongly sent for landfill disposal.

John Crofts, UKAEA director of safety said: "UKAEA deeply regrets that some particles were released from the site. Our priority today is to rectify those errors and minimise their impact on the environment."

Dounreay particles

One of the facilities at Dounreay was the Materials Test Reactor (MTR), used in research to develop materials suitable for commercial nuclear power stations. The design was exported by Britain to several other countries, and, because enriched uranium was a scarce commodity in the early days of nuclear research, all the fuel from those reactors was recycled at Dounreay.

Before recycling, aluminium cladding had to be manually removed from the highly-radioactive used nuclear fuel. This was performed remotely underwater, with the aluminium swarf - and any fragments of fuel damaged by the operator - building up in the pond water before removal for disposition.

Pond water was routed before sea discharge through the site's low-active liquid effluent system. Designers had sought to prevent any radioactive materials being discharged by the inclusion of settling tanks in which any remaining fuel fragments would be detected. Punler said that in 1983 routine environmental monitoring detected the first particle on a nearby foreshore. This revealed that the settling process was not adequate, and in early 1984 filters were fitted to the discharge system.

The prosecution was an admission that the lack of filters until 1984 meant that UKAEA had not fulfilled its obligation to 'use all reasonable practical means to prevent the release of particles' as required by successive statutory authorisations for the disposal of radioactive waste at Dounreay.

Now, UKAEA is engaged in a major programme to remove the tiny fragments from the environment and a total of 1401 have been detected on- and off-site. 80% of those particles have been traced to the recycling of MTR fuel. A short-list of 11 remediation options has been developed and is out for public consultation. Particle clean-up manager, Phil Cartwright, has said that the priorities of the public are crucial to weighing up the options for future clean-up.

Further information

UKAEA
Scottish Environmental Protection Agency

WNN: Dounreay fine: £140,000

---