One of the Navy’s oldest nuclear powered submarines has been ordered to return to dock for emergency repairs after a leak of radioactive coolant was discovered in its reactor compartment.
HMS Tireless, one of the Royal Navy’s ageing ‘Trafalgar’ class fleet submarines, arrived last week at HM Naval Base Devonport for repairs after the leak was detected during a training exercise off the west coast of Scotland, according to a report in the ‘Sunday Express‘ newspaper.
The submarine returned immediately to the Faslane naval base on the Clyde for inspections and will now enter dry dock at Devonport for the repairs, which are expected to take up to ten months to complete.
Leakage in the primary cooling circuit of a submarine’s reactor, if unchecked, could potentially lead to a major loss of coolant accident resulting in casualties among the submarine crew.
Tireless, launched in 1984, had been scheduled to retire from the Navy’s fleet this year, but its service life has been extended for a further four years because of delays in the Astute class submarine construction programme.
In 2011, the National Audit Office highlighted the risks that delays in the Astute programme would pose to the Navy’s submarine programme, warning that the Ministry of Defence “will have to use older boats beyond their out-of service dates, work the smaller fleet of Astute submarines harder, or reduce scheduled activity for submarines”. As a result, the Navy would not be able to meet its requirement for sufficient numbers of submarines to be available for operations over part of the next decade.
According to the Sunday Express, the Navy now has only five fleet submarines available to undertake duties scheduled for seven boats.
In May 2000 HMS Tireless was stranded at Gibraltar for a year while emergency repairs were made following the a coolant leakage resulting from cracks in welding in the submarine’s reactor cooling system. Similar cracking was found in the reactors on board six other submarines, which were withdrawn from service while repair work was completed.
A Royal Navy spokesperson said: “HMS Tireless returned to Devonport Naval Base last week for repair following a small coolant leak that was contained within the sealed reactor compartment. There is no risk to the public, the environment or the crew.”