The European Commission says it is taking the UK Government to court for allegedly breaking EU rules on the disposal of radioactive waste from Devonport Dockyard.
The disposal of radioactive waste took place in 2002
The commission says Britain failed to give the required notice when authorising nuclear waste removal from Devonport Dockyard last year.
The commission claims EU health assessment and radiation protection safeguards required under the Euratom Treaty were ignored.
The UK Government says the rules do not apply to military installations.
The Euratom Treaty lays down basic safety standards against the dangers from
The commission was informed in January 2002 that the UK Environment Agency was
about to authorise nuclear waste disposal from the Devonport Dockyard plant following the refitting and refuelling of nuclear submarines.
A commission statement said the authorisation was granted "without taking account of Euratom Treaty provisions and legislation regarding the protection of the health of workers and the general public."
The statement said: "Since the disposal of radioactive waste may affect another member state from a health point of view, assessment of the radiological impact of such waste by the commission remains crucial."
Officials sent a warning letter to the government earlier this year, but said on Thursday the case was now being referred to the European Court of Justice in Luxembourg because the issue remains "unresolved".
The Ministry of Defence (MoD) has long argued that the treaty does not apply to military installations.
An MoD spokesman said: "The commission and the UK disagree on the application of the Euratom Treaty in respect of military installations.
"The Courts of Justice will make a decision in due course.
"And I would like to stress discharge levels in Devonport Dockyard are well within safety limits."