YRC, Inc. violated CERCLA 103A by failing to immediately notify the NRC of a release of approximately 3,137 lbs. of sodium nitrite (RQ = 100 lbs.) and 9,412 lbs. of sodium hydroxide (RQ = 1000 lbs.) on 6/25/2010. The release occurred when the last trailer of a tandem semi-rig overturned on the guard rail while entering the ramp to Westbound I-74, Exit 119, Shelbyville, IN. The release should have been reported within 15 minutes of its occurrence, however, 3 hours and 58 minutes elapsed before the NRC was contacted.