As a student, Griffen became aware of the environmental and genetic impacts of radioactivity from French nuclear weapons testing in French Polynesia. She joined the anti-nuclear movement ATOM (Against Testing on Mururoa) and helped form the Nuclear Free and Independent Pacific network. In 1975 she was part of a group of 5 Fijian women who attended the United Nations' International Year of the Woman conference in Mexico City. She later joined the International Campaign to Abolish Nuclear Weapons and presented a statement at the United Nations negotiations on the Treaty on the Prohibition of Nuclear Weapons.