(1) The department may, upon application therefor or upon its own initiative, grant such exemptions or exceptions from the requirements of this chapter as it determines are authorized by law and will not result in undue hazard to public health and safety or property.

(2) Common and contract carriers, freight forwarders, and warehousemen, who are subject to the rules and regulations of the US department of transportation or the US postal service (39 CFR Parts 14 and 15) , are exempt from this chapter to the extent that they transport or store sources of radiation in the regular course of their carriage for another or storage incident thereto. Private carriers who are subject to the rules and regulations of the US department of transportation are exempt from this chapter to the extent that they transport sources of radiation. Common, contract, and private carriers who are not subject to the rules and regulations of the US department of transportation or the US postal service are subject to the applicable rules of this chapter.

(3) Any US department of energy contractor or subcontractor and any US nuclear regulatory commission contractor or subcontractor of the following categories operating within Montana is exempt from this chapter to the extent that such contractor or subcontractor under his contract receives, possesses, uses, transfers or acquires sources of radiation:

(a) prime contractors performing work for the US department of energy at US government-owned or controlled sites, including the transportation of sources of radiation to or from such sites and the performance of contract services during temporary interruptions of such transportation;

(b) prime contractors of the US department of energy performing research in, or development, manufacture, storage, testing or transportation of, atomic weapons or components thereof;

(c) prime contractors of the US department of energy using or operating nuclear reactors or other nuclear devices in a United States government-owned vehicle or vessel; and

(d) any other prime contractor or subcontractor of the US department of energy or of the US nuclear regulatory commission when the department and the nuclear regulatory commission jointly determine:

(i) that the exemption of the prime contractor or subcontractor is authorized by law; and

(ii) that under the terms of the contract or subcontract, there is adequate assurance that the work thereunder can be accomplished without undue risk to the public health and safety.