48 C.F.R. § 970.4402-3
(a) A management and operating contractor may purchase from sources affiliated with the contractor (any division, subsidiary, or affiliate of the contractor or its parent company) in the same manner as from other sources, provided—
(b) Subcontracts for performance of contract work itself (as distinguished from the purchase of supplies and services needed in connection with the performance of work) require DOE authorization and may involve an adjustment of the contractor's fee, if any. If the management and operating contractor seeks authorization to have some part of the contract work performed by a contractor-affiliated source, and that contractor's performance of that work was a factor in the negotiated fee, DOE approval would normally require—
(c) Determination on cost of money allowance as prescribed at 48 CFR 31.225-10 shall be treated as follows:
(1) When a purchase from a contractor-affiliated source results from competition and is in accord with provisions and conditions of paragraphs (a)(1) through (a)(4) of this subsection, the contractor-affiliated source may include cost of money as an allowable element of the costs of its goods or services supplied to the contractor; provided—
[65 FR 81009, Dec. 22, 2000, as amended at 74 FR 36374, July 22, 2009]