FACILITY FAILED TO IMMEDIATELY REPORT A 2,900 POUND RELEASE OF AMMONIA (29 C RQ) TO THE NATIONAL RESPONSE CENTER. AMMONIA IS A CERCLA HAZARDOUS SUBSTANCE WITH A 100 POUND REPORTABLE QUANTITY. THE FACILITY FAILED TO IMMEDIATELY NOTIFY THE NRC OF THE RELEASE. FACILITY NOTIFIED THE NFR 46 HOURS AND 26 MINUTES AFTER CONSTRUCTIVE KNOWLEDGE OF THE RELEASE.