The W.B. Lewis Medal was established in 1973 by the Canadian Nuclear Association in honour of Dr. W.B. Lewis, formerly Senior Vice-President (Science), Atomic Energy of Canada. The medal recognizes a Canadian scientist or engineer who has demonstrated a level of technical competence and accomplishment in the field of nuclear science and engineering as exemplified by the late Dr. W.B. Lewis during his involvement in the Canadian nuclear energy programme, 1946 to 1973.