10 C.F.R. § 1015.201
(e) DOE will refer debts to Treasury as soon as due process requirements are complete, and should refer such debts no later than 180 days after the debt has become delinquent. On behalf of DOE, Treasury will take appropriate action to collect or compromise the referred debt, or to suspend or terminate collection action thereon, in accordance with the statutory and regulatory requirements and authorities applicable to the debt and action. Appropriate action to collect a debt may include referral to another debt collection center, a private collection contractor, or the DOJ for litigation. (See 31 CFR 285.12, Transfer of Debts to Treasury for Collection.) This requirement does not apply to any debt that: