Then-taoiseach John Bruton raised the issue with British prime minister John Major after several safety incidents over a short period in the 1990s.

The UN nuclear watchdog agency says Tehran has agreed to allow inspectors in to two sites where Iran is suspected of having stored or used undeclared nuclear material.

North Korea leader Kim Jong Un said his country’s hard-won nuclear weapons were a solid security guarantee and a “reliable, effective” deterrent that could prevent a second Korean War, state media has reported.

The cause of a fire at Iran’s Natanz nuclear site is known, but will not be made public at this time due to “security reasons”, a security spokesman said.

A fire and an explosion struck a building above Iran’s underground Natanz nuclear enrichment facility early on Thursday. It was a site that US-based analysts identified as a new centrifuge production plant.