accident in which the primary coolant of a nuclear reactor is lost at a rate that exceeds the capability of the make-up system, those postulated accidents that result in a loss of reactor coolant at a rate in excess of the capability of the reactor makeup system from breaks in the reactor coolant pressure boundary, up to and including a break equivalent in size to the double-ended rupture of the largest pipe of the reactor coolant system, õnnetus, mille käigus tuumareaktori esmane jahutusvedelik lekib kiirusega, mis ületab lisaveesüsteemi vee reaktorisse sisestamise võimekust