48 CFR §970.1170-1

Each contract for the management and operation of a DOE site or facility, and other contracts designated by the DOE or the National Nuclear Security Administration (NNSA) Senior Procurement Executive, must contain a scope of work section that describes, in general terms, work planned and/or required to be performed. Work to be performed under the contract shall be assigned through the use of a work authorization to control individual work activities performed within the scope of work. Work authorizations must be issued prior to the commencement of the work and incurrence of any costs.