5 CFR § 842.904 - Conditions for coverage in secondary positions.
(a) An employee's service in a position that has been determined by the Secretary of the Department of Energy to be a secondary nuclear materials courier position following 3 years of service in a primary nuclear materials courier position is covered under the provisions of 5 U.S.C. 8412(d) if all of the following criteria are met:
(1) The employee is transferred directly (i.e., without a break in service exceeding 3 days) from a primary position to a secondary position; and
(2) If applicable, the employee has been continuously employed in secondary positions since transferring from a primary position without a break in service exceeding 3 days, except that a break in employment in secondary positions which begins with an involuntary separation (not for cause), within the meaning of 5 U.S.C. 8414(b)(1)(A), is not considered in determining whether the service in secondary positions is continuous for this purpose.
(b) An employee who is not in a primary position, nor covered while in a secondary position, and who is detailed or temporarily promoted to a secondary position is not covered under the provisions of 5 U.S.C. 8412(d).