NIREX was a body set up in 1982 in the UK to examine safe, environmental and economic aspects of deep geological disposal of intermediate- and low-level radioactive waste produced by the nuclear power industry.

In the 1980s, NIREX had gained waidespread notoriety as the focus for public opposition to the burying of nuclear waste in the UK. Its main roles as an organisation were to advise organisations and companies that produce radioactive waste on how to properly package it, setting standards for waste packagine, producing a public record of the quantities and types of radioactive waste in the UK, and continuing to develop understanding of the scientific, technological, and environmental options for dealing with radioactive waste.

In 2006, ownership of NIREX was transferred from the nuclear industry to the UK Nuclear Decommissioning Authority (NDA). By April 2007, NIREXs staff and functions were integrated into the NDA and NIREX ceased trading as a separate entity.

It was headquartered in Harwell, Oxfordshire.