The Dounreay nuclear power plant’s decommissioning is a massive undertaking. Reports from the Builder and Engineer
The Dounreay site of the United Kingdom Atomic Energy Authority faces exciting and challenging times ahead. The plant’s decommissioning is being accelerated, which will necessitate extensive planning of the upcoming major works.
The nuclear industry was brought to this picturesque location on Scotland’s north coast in the mid-1950s, when the government established the United Kingdom Atomic Energy Authority (UKAEA) to develop nuclear energy uses.
Dounreay was chosen as the best location for the company’s new experimental reactor. Construction of the Dounreay Materials Test Reactor (DMTR) began in 1955, with no time wasted. The DMTR was decommissioned in 1969, but the Dounreay Fast Reactor (DFR) had already been operational for ten years.
The third and final reactor on the site was the Prototype Fast Reactor (PFR), which began operations in 1974 and remained operational until 1994.
A number of laboratories and chemical plants were also constructed to handle the fuel for these reactors, as well as facilities for the chemical treatment, storage, and disposal of nuclear waste, as appropriate.
For many years, Dounreay was the world’s most advanced nuclear facility of its kind.
However, the UKAEA is now faced with the task of decommissioning the site and dealing with the nuclear waste and materials that have accumulated after 40 years of nuclear operations. More radioactive waste will be generated and must be managed as a result of this.
The mission to restore the environment will take 50 to 60 years and will involve 1,500 different activities; therefore, the UKAEA has developed a comprehensive and integrated plan to address the restoration of the Dounreay site.
The Dounreay Site Restoration Plan (DSRP) is the most detailed plan for the decommissioning of a nuclear site ever produced anywhere in the world.
Dounreay’s historic step of becoming the first nuclear plant to publish its entire work programme for public scrutiny was only the first step toward better communication with its many stakeholders.
An extensive series of discussions and presentations to stakeholders about the plan has been followed by a communications strategy that includes a commitment to consult the public on specific waste disposal options.
The DSRP will enable UKAEA to adapt to and respond to unexpected issues, as well as capitalise on new opportunities and technological advances as they arise.
Decommissioning this nuclear site will require not only the demolition of buildings, but also periods of heavy construction. To eliminate all major radiological hazards within 25 years, up to 20 new facilities to treat waste and process nuclear materials will need to be built.
The plan divides the work into five phases, each lasting about 10 to 15 years and spanning a time span of 50 to 60 years.
Along with the continuation of decommissioning, contractors will build many of these new facilities during stage one.
Working alliances have already been formed for some of the major tasks in the first stage of PFR and DFR decommissioning.
JGC Engineering and Technical Services, Babtie, Ingenco, and Alstec have formed a £15 million alliance with UKAEA to deal with sodium residues over the next three to five years of PFR decommissioning.
Much work has already been completed. After the reactor was shut down in 1994, all of the nuclear fuel was removed, and a £17 million plant was built to dispose of the bulk coolant.
The next stage of decommissioning will remove any remaining traces of the liquid sodium metal used to cool the reactor core.
An alliance is being formed in order to remove the last of the fuel from the Dounreay Fast Reactor. The DFR Primary Circuit Decontamination Alliance is made up of six companies that will decontaminate the reactor vessel and pipework for £30 million. Halcrow, Interserve, Edmund Nuttall, Mitsui, NNC, and Framatome are among them.
They plan to use robots inside the reactor’s concrete vault to cut up and remove more than 9km of contaminated pipework. This phase of work will last at least until 2013. “This is a significant step forward in the site’s restoration,” said Dounreay site director Peter Welsh.
“When this alliance completes its mission, we will have completed the first and most critical stage of decommissioning a reactor.” This is one of the site’s major engineering and environmental challenges.”
The UKAEA anticipates that about £10 million of the Primary Circuit contract value will go to local companies, and that an initial 50 jobs will be created or retained in the region.
The transfer of specialist skills, such as robotics, from major contractors to local firms will be a key goal of the alliance. This will help them compete for future decommissioning work at Dounreay and elsewhere around the world.
During 2000/01, the decommissioning work at Dounreay injected approximately £61 million into the Caithness economy.
Contracts cost Dounreay £80 million. Caithness received £4.2 million, the rest of the Highlands and Islands received £600,000, the rest of Scotland received £8.5 million, and English companies received £66 million. Subcontracts worth £30 million were also awarded to Caithness firms.
“Decommissioning provides an excellent opportunity for UK companies to undertake the necessary clean-up work,” said a UKAEA spokesman. “UKAEA is working closely with Highlands and Islands Enterprise and Caithness and Sutherland Enterprise to maximise the benefits of decommissioning Dounreay to the local economy.”
Dounreay’s remote location in Caithness makes recruitment more difficult than at UKAEA’s other sites: Windscale, Risley, Culham, Harwell, and Winfrith. Nonetheless, the company has successfully hired around 300 new employees in the last few years.
The intense construction and decommissioning periods will make the decommissioning project one of the largest engineering and construction challenges in Scotland, requiring a significant amount of financial and human resources.
“Restoring our environment and dealing with the legacies of our operational past will cost more than £4 billion and take many years,” Welsh says. “Our spending has nearly doubled in the last few years and is now in the order of £140 million to £150 million per year – a level we expect to maintain for the next decade.”
Contractors and consultants on the project have three main responsibilities: providing technical support, implementing the work, and providing routine services.
“Decommissioning is a significant opportunity for companies of all sizes – and not just at Dounreay,” Welsh said. “I believe the skills and experience that will be gained here as decommissioning progresses will be sought after globally.”
Alliances provide significant opportunities for smaller businesses. “This is the entry point for smaller businesses to grow and expand in what will become a massive global marketplace,” he explained.
To manage the decommissioning work, UKAEA is developing a core of technical, project management, risk analysis, safety, health, and environmental expertise.
All contracts are advertised on the UKAEA website, and those worth more than £150,000 are listed in the European Union’s Official Journal. Typically, the UKAEA will invite several bidders to present detailed solutions, which will be evaluated by expert technical and cost panels.
Firms are judged based on their track record, technical and financial strength, safety and quality record, manpower, and problem-solving abilities. A diverse set of skills is essential for a project as complex as the decommissioning of a major nuclear power plant.