10 C.F.R. § 820.5 – Service.

(a) General rule. Any document filed with the Docketing Clerk must be served on the addressee of the document and shall not be considered filed until service is complete and unless accompanied by proof of service; provided that the filing with the Docketing Clerk of any document addressed to the DOE Official shall be considered service on the DOE Official.
(b) Service in an Enforcement Adjudication. Any document filed in an enforcement adjudication must be served on all other participants in the adjudication.
(c) Who may be served. Any paper required to be served upon a person shall be served upon him or upon the representative designated by him or by law to receive service of papers. When an attorney has entered an appearance on behalf of a person, service must be made upon the attorney of record.
(d) How service may be made. Service may be made by personal delivery, by first class, certified or registered mail or as otherwise authorized or required by the DOE Official. The DOE Official may require service by express mail.
(e) When service is complete. Service upon a person is complete:
1. (1) By personal delivery, on handing the paper to the individual, or leaving it at his office with his clerk or other person in charge or, if there is no one in charge, leaving it in a conspicuous place therein or, if the office is closed or the person to be served has no office, leaving it at his usual place of residence with some person of suitable age and discretion then residing there;
2. (2) By mail, on deposit in the United States mail, properly stamped and addressed; or
3. (3) By any other means authorized or required by the DOE Official.
(f) Proof of service. Proof of service, stating the name and address of the person on whom served and the manner and date of service, shall be shown for each document filed, and may be made by:
1. (1) Written acknowledgement of the person served or his counsel;
2. (2) The certificate of counsel if he has made the service;
3. (3) The affidavit of the person making the service; or
4. (4) Any other means authorized or required by the DOE Official.
(g) Deemed service. If a document is deemed filed under this part, then the service requirements shall be deemed satisfied when the document is deemed filed.