Fears that a nuclear-powered Soviet satellite might crash to Earth in Ireland triggered a plan from the Nuclear Energy Board, according to a report supplied to the taoiseach's office in 1984.

The board's report, covering its activities in the previous year, is contained in files from the Department of the Taoiseach archives and was submitted to government in December 1984.

It said the board had sought advice about a Soviet satellite known as Cosmos 1402, which was out of control and would re-enter the Earth's atmosphere.

“It was a nuclear powered satellite similar to that which fell back to Earth some years previously and contaminated an area of northern Canada,” the report said.

It said the Soviet government had given assurances that no hazard existed, but most countries had developed a plan for the monitoring and clean-up of radioactive material.

The board drew up such a plan for the inter-departmental committee on emergency preparations.

The Army carried out airborne trials of the board’s radiation equipment, which tested its sensitivity and helped the board to develop a realistic search method.

"The satellite's reactor re-entered the Earth's atmosphere over the south Atlantic Ocean and was reported to have burnt up completely, thus there was no need for protective action," the report said. The board ceased operating in 1992 and was replaced by the Radiological Protection Institute of Ireland.