Key subcontractors Vinci and Nuvia pulled around 100 staff off the job earlier this year when work was halted to carry out the review.
The contract to complete engineering design, construction and commissioning of the SDP is now estimated to be worth £800m-£1.4bn.
The large and technically complex treatment plant will handle radioactive liquid waste, which will be mixed with cementitious material to allow it to be stored in containers within existing Sellafield stores.
The SDP Project is a key part of the waste retrieval hazard reduction programme for the ‘wet’ silos, which is of strategic importance to the Nuclear Decommissioning Authority.
Further information will be published on the tendering portal tomorrow.