Anti-nuclear activist Sister Ardeth Platte, a Dominican nun who spent time in jail for her peaceful protests, died in her sleep on Sept. 30. She was 84.

Sister Carol Gilbert, who confirmed Platte's death, lived with her at a Catholic Worker house in Washington, D.C. Gilbert said Platte had participated in a street corner demonstration against nuclear weapons just a few days before her death.

In 2010, Platte was arrested for trespassing at the Y-12 National Security Complex in Oak Ridge, Tennessee, during a protest, according to the Knoxville News Sentinel. At her sentencing hearing, Platte said, "Nuclear weapons are the taproot of violence, and they must be abolished. So I refuse to be silent," the newspaper reported. She served a four-month sentence. It was one of several arrests over many years of anti-war protests.

In October 2002, Platte, Gilbert and one other Dominican nun, the late Sister Jackie Hudson, poured their own blood on a Minuteman III missile loaded with a 20 kiloton nuclear bomb in Weld County, Colorado. It was one of 49 high-trigger nuclear weapons stored in the state. Their action symbolized taking it offline.

They were convicted of sabotage and received harsh sentences: 41 months for Platte, 33 for Gilbert and 30 for Hudson.

In September 2000, the three were arrested for civil disobedience at Peterson Air Force Base in Colorado Springs and jailed. The charges were subsequently dropped. They've also served time in other states for nonviolent acts of civil disobedience.

A report in a Dominican Sisters newsletter provided by Gilbert says Platte grew up in Westphalia, Michigan, and in 1954 entered the Dominican Sisters of Grand Rapids at 18. She was a Dominican nun for 66 years. The newsletter calls Platte a "justice preacher, peace seeker, teacher, compassionate neighbor and friend who stood with people on the margins."