10 CFR §75.44

1. (a)Except as provided in paragraph (b) of this section, notification to the Commission, when required by § 75.43, must be given:
   1. (1)In the case of exports and domestic transfers, at least 20 days in advance of the preparation of the nuclear material for shipment from the facility.
   2. (2)In the case of imports, at least 12 days in advance of the unpacking of nuclear material at the facility.
2. (b)For a particular receipt or shipment of nuclear material, the Commission will approve a shorter notice period than that specified by paragraph (a) of this section, for good cause, if it determines that observing the specified notification period would result in delay in shipment or unpackaging.
3. (c)The licensee shall inform the Commission, by phone, as soon as possible, with respect to any delay in the receipt (or unpackaging) or the shipment (or preparation for shipment) of nuclear material for which advance notification is required. New dates should be provided, if known.