Nihon Hidankyo, a grassroots Japanese organization of atomic bomb survivors, has been awarded this year’s Nobel Peace Prize for their decades-long activism against nuclear weapons. The Norwegian Nobel Committee recognized the group “for its efforts to achieve a world free of nuclear weapons and for demonstrating through witness testimony that nuclear weapons must never be used again.

Last year, jailed Iranian human rights activist Narges Mohammadi won the Nobel Peace Prize for her fight against the oppression of Iranian women. Winners are awarded a medal, diploma, and 11 million Swedish kroner, the equivalent of slightly more than $1 million. The ceremony for the award will be held in Oslo on Dec. 10.

The recipient of this year’s Nobel Peace Prize is a fast-dwindling group of atomic bomb survivors. They're increasingly worried about their old age and the limited time to convey the firsthand horror they witnessed 79 years ago.