THOUSANDS of Portland residents are to be given information packs telling them what to do in a nuclear emergency.

The Ministry of Defence is taking a range of measures in response to the reinstatement of visits by Royal Navy nuclear-powered submarines to Portland Port.

Tomorrow it will start the distribution of the booklets to around 4,300 people living within a 2km radius of the Portland berth.

The guides will inform them of the relevant hazards and contingency plans in the very unlikely' event of an accident involving a nuclear-powered vessel.

The MoD teamed up with Portland Port, Dorset County Council and Weymouth and Portland Borough Council to draw up the emergency response plans in accordance with the Radiation (Emergency Prepared-ness and Public Information) Regulations 2001.

The contingency plan will be similar to one already in existence for Southampton that covers areas such as media warning strategies, inter-agency response and the distribution of potassium iodate tablets (PITs).

The Southampton plan, Soton-Safe, also gives residents advice on what to do if the worst should happen. It says: 'Those residents living within an area up to 2km downwind from the berth will be advised to take shelter indoors and take the tablets if/when directed. Those working or in transit within the 2km zone downwind should self evacuate the area'.

Dorset County Council and the MoD will be conducting Operation Shortbill 2007, a test of the emergency plan and the site specific operator's emergency plan, on April 13.

Dorset county emergency planning officer Simon Parker said: "We have been working in partnership with the Royal Navy, Portland Port and other agencies to produce this plan and prepare for the testing of the emergency arrangements for nuclear submarine visits to Portland Port.

"Operation Shortbill 2007 will be witnessed by the Health and Safety, Executive Nuclear Installations Inspectorate and Defence Nuclear Safety Regulator, who will comment on the arrangements before any submarine visit is finalised."

The council aims to ensure that members of the public will not be affected by the exercise.

The emergency plan will be available for viewing on the Dorset County Council website

Portland residents who receive information booklets should keep them in a safe place and will receive a new one every three years.