During deuterium (D–D fuel) plasma experiments in 1998, plasma conditions were achieved which would have achieved break-even—the point where the power produced by the fusion reactions equals the power supplied to operate the machine—if the D–D fuel were replaced with a 1:1 mix of deuterium and tritium (D–T fuel). JT-60 does not have the facilities to handle tritium; only the JET tokamak in the United Kingdom has such facilities as of 2018. In fusion terminology, JT-60 achieved conditions which in D–T would have provided a fusion energy gain factor (the ratio of fusion power to input power) Q = 1.25.[6][7][8] A self-sustaining nuclear fusion reaction would need a value of Q that is greater than 5.[3][9][10]