The first project is a managed services contract at Sizewell in Suffolk, the second contract is for programme management support at the Berkeley site in Gloucester .
Mace will manage the delivery of projects as part of the decommissioning programmes.
John Bradshaw, Mace energy director said: “The nuclear decommissioning market is at the very heart of the most highly regulated and complex industry sector.
“Securing work in this new market for Mace strengthens our service offer of bringing our expertise from other infrastructure and highly regulated sectors and applying it to the nuclear sector.”
Magnox, owned by EnergySolutions, is the management and operations contractor responsible for 10 nuclear sites in the UK.