A 16-piece tool dubbed the world's most sophisticated Swiss Army knife is to help dismantle the Dounreay Fast Reactor (DFR) in Caithness. The device cost £20m to design and build and will operate in highly radioactive conditions inside Dounreay's landmark Dome. Its detachable tool bits cost £100,000 each and weigh between 37-93kg. They will cut and grab 977 metal rods once used to "breed" plutonium from uranium. Measuring about 2.5m (8ft) in length, the rods resemble thin sections of scaffolding. UK government agency, Nuclear Decommissioning Authority (NDA), has proposed transporting the metal, which is known as breeder material, by train to Sellafield in Cumbria to be reprocessed. The new 4m (14ft) long device has been moved into position above the DFR's reactor vessel, ready to be lowered into the darkness of the reactor vessel where it will "harvest" the metal rods. Before this work can start, a liquid metal will have to be drained from the vessel over the next 12 months. The tool is also being put through a series of "robust" tests and its operators are receiving training. Once in place, the device will operate in highly radioactive conditions and in a nitrogen atmosphere. Nitrogen prevents any residue of the liquid metal from reacting. Continue reading the main story Dounreay factfile The Dounreay Fast Reactor operated between 1959 and 1977 Two thousand metal rods had surrounded the DFR's core More than half were removed during the 1980s. However, a number were found to be jammed in place and Dounreay also ran out of storage space for removed rods Exposure to water or oxygen would cause the metal to catch fire. Alex Potts, the engineer in charge of the Dounreay Site Restoration Limited (DSRL) project, said it was too dangerous for people to work inside the reactor vessel. He said: "The reactor was a one-off design and so is the tool we need to take out the breeder rods. "It's too toxic in there for anyone to do the job manually - the radiation levels are still very high and the residual traces of liquid metal coolant add to the hazard - so we need a tool capable of doing the job by remote control. "It's a pretty sophisticated version of a Swiss army knife the team came up with." Up to three tool bits will be in use at any one time and can be replaced by another three carried in a special tool box without the need to remove the tool itself from the reactor. The pipe crawler has been among Dounreay's other hi-tech tools The rest of the tool bits will be stored above the reactor and would be fitted into place during service and maintenance breaks. Special radiation-proof cameras and spotlights will guide operators working around the clock in a control room 6m (20ft) above the reactor. The device, designed and built by French firm Framatome, is among the most expensive in the Dounreay "tool box". Others include a £100,000 pipe crawler, a device described by its operators as a hi-tech worm, which was deployed to probe the condition of a pipeline once used to discharge radioactive effluent from the site. A van-sized machine has also been retrieving radioactive particles from the seabed near Dounreay. But project costs have also been cut with the use of household cleaning products in the clean-up of equipment removed from the experimental nuclear power plant.

The US general who has taken over as commander of international forces in Afghanistan has warned of "tough days ahead" in the military campaign.

Addressing troops at a handover ceremony in Kabul, Gen John Allen said he had "no illusions about the challenges we will face together".

Insurgents have stepped up attacks on troops and senior Afghan officials.

Gen Allen has taken over command from Gen David Petraeus who is returning to the US to run the CIA.

Gen Petraeus oversaw last year's surge of US troops to Afghanistan.

The change in command comes as the Nato-led International Security Assistance Force (Isaf) begins passing control of some areas to its Afghan counterparts.

Gen John Allen said his intention was 'to maintain the momentum of this campaign'

Foreign troops are due to end combat operations in Afghanistan by 2014.

Despite the transition, attacks by militants continue to claims lives. On Monday three Nato soldiers were killed by a roadside blast in the east of the country.

Seven Afghan police officers were also killed in the district of Lashkar Gah, in volatile Helmand province, on Monday, Afghan officials said.
'Challenges'

"It is my intention to maintain the momentum of this campaign, this great campaign on which we have embarked," said Gen Allen.

"I will continue to support, in every way possible, the recruiting, the training, the preparation and the equipping and the fielding and employment of Afghan national security forces."

He added: "There will be tough days ahead and I have no illusions about the challenges we will face, challenges we will face together but I have this certainty that brave men and women of 49 nations shoulder-to-shoulder, will, with our Afghan partners, continue this great work."
Continue reading the main story
GEN JOHN ALLEN
Graduated from the US Naval Academy in 1976, but went on to further degrees in national security and strategic intelligence
Served in the Caribbean, the Balkans and was deployed to Iraq in 2006
Between 2008 and 2011 he was deputy commander of US Central Command
Promoted to the rank of four- star general shortly before assuming command of troops in Afghanistan

Gen Petraeus took charge in Afghanistan last year and managed the deployment of more than 30,000 additional US troops to fight the Taliban. US troops are set to begin the first phase of their withdrawal in the coming months.

A spokesman for the governor of Helmand said seven members of the Afghan National Police Force were killed by gunmen at a checkpoint in Lashkar Gah on Monday.

Central Lashkar Gah is due to be handed over by British forces to Afghan control on Wednesday.

The spokesman said the attack took place just outside the area due to be handed over.

Also on Monday, Canada's most senior officer in Afghanistan, Brig Gen Dean Milner, flew out of Kandahar with the last of Canada's combat troops there. Some Canadian forces will remain to help train Afghan troops.

Nato forces handed control of Bamiyan province to local forces on Sunday.

It was the first of seven areas to be passed to Afghan security forces under the plan announced by President Karzai in March.

On Sunday a close aide to President Karzai, Jan Mohammad Khan, died in an attack in Kabul.

The incident came less than a week after Mr Karzai's brother, Ahmed Wali Karzai, was assassinated.