THOUSANDS of people could be contaminated with radio activity in breach of safe limits if there was an accident on a nuclear submarine at the Faslane naval base on the Clyde, a MOD assessment reveals. A leaking submarine reactor could give everyone within two kilometres a radiation dose that would increase their cancer risk. The MOD admits the contamination could spread wider and cause “more significant consequences” in some incidents.

The same risks are also faced by people living near six other sites in Scotland where nuclear submarines can berth. Three of them are around the Clyde, and three are in the Highlands.

In response to a request from the Sunday Herald, the MoD’s new assessment of the accident risks at Faslane was released. This Hazard Identification and Risk Evaluation was conducted under the government’s Radiation (Emergency Preparedness and Public Information) Regulations (REPPIR).

For submarine reactors, the assessment “identified a number of scenarios that could lead to an offsite release of radioactive material”. These would trigger a “radiation emergency” which could last “several hours”. Members of the public within two kilometres of the accident could be exposed to more than five millisieverts of radiation. The internationally recommended safety limit is one millisievert a year. The assessment shows there are 1000 to 1600 people living within two kilometres of nine potential accident sites at Faslane. In addition, there are more than 3000 workers on the base at any one time.

The MoD does point out: “For a significant release to occur it is necessary for there to be a plant failure followed by a breach of multiple containment barriers.”

The potential accidents analysed by the MoD include a loss of coolant from the submarine reactor and runaway chain reactions. Emergency measures in the event of an accident include evacuation and advising people to take shelter to minimise radiation exposure. People will also be asked to take iodine tablets, which can reduce the risk of thyroid cancer.

But these plans are dismissed by independent nuclear consultant John Large as “totally inadequate”. He says that under the worst scenario conceived by the MoD, radioactive contamination could reach high levels as far as 30km from an accident. If its cooling system failed, a reactor could melt down, explode and rip open a submarine hull in 20 minutes, Large claims. “This would be a very bad accident and it would cause chaos. The risks from a naval reactor are significantly higher than the risks predicted for civilian reactors. It’s a whole different kettle of fish.”

The navy says there are three other places around the Clyde where nuclear submarines can berth. They are the explosives handling jetty at Coulport on Loch Long, an anchorage known as B4 between Gourock and Dunoon, and Loch Goil. There are also two berths in Loch Ewe off Wester Ross. According to the MoD, one is a buoy within two kilometres of the 150 people living in Mellon Charles, and the other is a jetty close to 350 people in Aultbea.

The MoD assessment of the other berth – at Broadford Bay off Skye – suggests 526 people are at risk of radioactive contamination from an accident.

Commons Question - 2nd March:- Pete Wishart: To ask the Secretary of State for Defence (1) what assessment he has made of potential risks arising from (a) an accident and (b) human error in relation to the transportation of nuclear warheads within the naval base on the Clyde; [218348]

(2) what estimate he has made of potential casualties in the west of Scotland arising from a catastrophic malfunction of a Trident nuclear warhead on a submarine based in the Clyde. [218347]

Mr. Hoon: At HM Naval Base Clyde, nuclear warhead handling, storage, transportation and fitting of components is carried out using rigidly controlled and approved procedures, and staff undertaking these activities undergo extensive training before they are designated competent to carry out the work. The potential risks arising from an accident and human error are therefore very low. It is also highly unlikely that a catastrophic malfunction of a nuclear warhead that involved nuclear yield (a high explosion and the release of radioactive material), would occur, whether onboard a submarine or elsewhere within the Naval Base.

Risks to employees, members of the public and the environment are routinely assessed during preparation of the Hazard Identification and Risk Evaluation (HIRE), which is the responsibility of the local authority and which is a requirement of the Radiation (Emergency Preparedness and Public

Information) Regulations 2001 (REPPIR). Such planning is based on a vigorous precautionary approach and the chances of any incident happening, for which the REPPIR emergency plans have been prepared, have been assessed as highly unlikely.