By Natalie Huet and Peter Schwartzstein
LONDON, Dec 12 (Reuters) - A disgruntled British sailor who tried to pass military secrets to Russia because he was fed up with Britains's Royal Navy was jailed for eight years on Wednesday.
Petty Officer Edward Devenney, 30, was caught in a sting operation in January as he tried to hand over classified information about British nuclear submarines to men he thought were Russian agents.
"The defendant was prepared to betray his country and his colleagues," Judge John Saunders said. "Those who serve their country loyally must know that those who don't will receive proper punishment."
Devenney, who had been in the Navy for 10 years, had not asked for anything in return for the information but said he was disillusioned after a missed promotion opportunity and wanted to "hurt the Royal Navy", the court heard.
The information, if passed on, could have led to the capture of the nuclear submarine HMS Vigilant's unique signature - the sound it makes as it passes through water - which could have resulted in it losing its capacity to go undetected.
Devenney, from Northern Ireland, had served on three of Britain's four Trident class nuclear submarines, a critical part of the country's nuclear deterrent, and had specialised in maintaining communications systems.
"He was something of a blue-eyed boy in the Royal Navy, a high-flyer with the potential for a commission," his Defence counsel Lord Carlile said.
The court heard that he had suffered from bouts of depression and binge drinking after he was accused and later acquitted of rape in 2010.
His behaviour had become a source of concern to his superiors and in 2011 he was withdrawn from a training course that could have led to him being promoted.
The case comes at a time of tense relations between Britain and Russia, particularly after the death of former Russian spy and Kremlin critic Alexander Litvinenko from radioactive poisoning in London in 2006.
SECRET COURT SESSION
The court heard that on Nov. 17, 2011, Devenney made 11 calls to the Russian embassy in the middle of the night.
Two days later, on board HMS Vigilant, he took three photographs of material used to encrypt or decrypt classified information and downloaded them to his personal computer.
For the next three months he exchanged calls and text messages with two men purporting to be Russian agents.
On Jan. 28, Devenney met his contacts, who called themselves "Dima" and "Vladimir" at the British Museum in London before heading to a hotel.
There, unaware he was being taped, he offered to share information, saying: "I have the potential to get whatever's in the system".
He arrested in March in the southwestern port of Plymouth.
Part of the court proceedings were held behind closed doors for national security reasons.