Cavendish Nuclear secures skyline changing decommissioning contract at Dounreay

Cavendish Nuclear, the UK’s leading nuclear services business, is to carry out the dismantling and demolition of Scotland’s oldest nuclear reactor.

Dounreay Site Restoration Ltd, the site licence company responsible for the clean-up and closure of the former nuclear research facility, awarded the multi-million pound contract to Cavendish Nuclear for the final phase of decommissioning the Dounreay Materials Test Reactor (DMTR) following a competitive tendering exercise.

Working with key supply chain partners, Cavendish Nuclear expects to take three years to complete the removal of the reactor.

The Nuclear Decommissioning Authority’s director of nuclear operations, Alan Cumming, said, “The start of the work to demolish the DMTR represents a significant step in our mission to decommission and clean-up the legacy from the very earliest days of the UK’s nuclear industry.”

Cavendish Nuclear director Natalie Nesbit said, “I am delighted our innovative and collaborative approach to reactor dismantling, using proven and cost-effective technology in conjunction with the local supply chain, will deliver the greatest skyline change seen at Dounreay for many years.”

DMTR became Scotland’s first operating reactor when it achieved criticality in 1958. It was used for irradiation tests on materials until its shutdown in 1969. The fuel, heavy-water coolant and redundant plant have been removed, leaving the reactor vessel, supports and containment shell ready for final removal.

Cavendish Nuclear will combine proven, off-the-shelf technology with tight controls on radiological exposure and radioactive contamination to safely remove the remaining structures from the inside out.

Expected low dose rates remove the need for complex, remotely-operated tooling and allow for stricter segregation at source of different waste streams, avoiding the unnecessary and costly accumulation of contaminated material.

Cavendish Nuclear has appointed JGC Engineering and Technical Services, KDC and Frazer-Nash Consultancy as its key supply chain partners.

Caithness-based JGC will carry out the removal of equipment and decommissioning of the reactor block. The company is one of the most experienced in decommissioning work at the site, and recently completed the removal of the adjoining D1251 ancillary building as well as numerous other decommissioning projects over many years across the Dounreay site.

Director Stephen Sutherland said, “The team at JGC are delighted to be working with Cavendish Nuclear on such a high profile project as the decommissioning of the DMTR facility and look forward to delivering a safe and successful project to DSRL over the next three years.”

JGC will be supported by local subcontractors Gunn’s of Lybster, Caithness Scaffolding and Hugh Simpson Ltd during the works phase.

KDC carried out the last decommissioning of a similar research reactor in the UK – the Consort facility at Imperial College in London 2015-17.

Frazer-Nash, a subsidiary of Babcock International Group, will augment Cavendish Nuclear’s safety case and engineering capabilities.

Cavendish Nuclear and its partners have pledged to source materials and services from local sub-contractors as part of a commitment to the socio-economic development of Dounreay’s supply chain and wider Caithness community.