NUCLEAR REACTOR PRESSURE VESSELS

THIS STUDY IS TO DEVELOP AN INSTRUMENT TO NONDESTRUCTIVELY EVALUATE THE DEGREE OF EMBRITTLEMENT OF FERRITIC NUCLEAR REACTOR STEELS DUE TO PROLONGED EXPOSURE TO NEUTRON IRRADIATION. CURRENTLY, ONLY DESTRUCTIVE TECHNIQUES ARE AVAILABLE USING SMALL SURVEILLANCE SAMPLES EXPOSED WITHIN A REACTOR. THE PRIMARY METHOD IS MAGNETOMECHANICAL ACOUSTICEMISSION, SUPPLEMENTED BY MAGNETIC AND EDDY CURRENT TESTING METHODS. DATA ACQUISITION WILL BE COMPUTERIZED AND PROCESSED FOR MUTUAL CORRELATION. INITIALLY, THERMAL DAMAGES ARE ANALYZED FOLLOWED BY MEASUREMENTS ON IRRADIATED SAMPLES. IN THE STUDY, ACOUSTIC SIGNALS IN THE RANGE OF 30 KHZ TO 2 MHZ WILL BE EXHAUSTIVELY ANALYZED IN RELATION TO APPLIED ALTERNATING MAGNETIC FIELDS BELOW 60 HZ. SUBMICROSCOPIC DAMAGES ARE EXPECTED TO INTERACT WITH MAGNETIC DOMAINS AND AFFECT THE GENERATION OF ACOUSTIC SIGNALS.