Rice, who suffered from congestive heart disease, died at Holy Child Center, Rosemont, Pennsylvania on Oct. 10, according to her order, the Society of the Holy Child Jesus.
Carroll Juliano, American Provincial Leader for the Order, stated that Sister Megan lived her life full of love and action. "Her unwavering commitment to building a peaceful, just world was selfless and unwavering."
Rice was the child of activist parents in New York. She would have met Dorothy Day, a well-known Catholic writer, during the Great Depression to find solutions to societal problems.
Her uncle was also heavily involved in her activism. He spent four months in Nagasaki (Japan) after Hiroshima and Hiroshima were destroyed by atomic bombs. These bombings, which Rice later called the "greatest shame" in history, helped to accelerate the end of World War II.
As a teenager, she joined the Society of the Holy Child of Jesus in order to become a nun. In 1955, she made her last vows and assumed the religious title Mother Frederick Mary. Rice received degrees at Villanova University and Boston University, where a Master in Science was earned.
Before being assigned to Nigeria, she taught elementary school in New Jersey, Pennsylvania, and Massachusetts for over a decade.
Rice worked as a teacher and pastoral guide for 23 years in West Africa. Rice was there when she first heard about the plowshares movement. This refers to a Bible verse that speaks of the end to all wars: "They will turn their swords into ploughshares."
Rice became involved in anti-nuclear activism after she returned to the U.S.
Court records indicate that she was already convicted four times of protest activities in the case against her and two other Catholic peace activists, Greg Boertje–Obed and Michael Walli, when they broke into Oak Ridge's Y-12 National Security Complex, Tennessee in July 2012.
They cut through many fences to reach a bunker that held much of the nation's bomb grade uranium. There they spent two hours hanging banners, praying, hammering on the bunker, and spray-painting peace slogans.
They were both charged with felony sabotage. According to court records, Rice and her codefendants were described by federal prosecutors as "recidivists" and "habitual offenders" who would again break the law "as soon they are physically able to do so," according Federal prosecutors.
Rice's lawyers requested leniency from U.S. district Judge Amul Thapar. They argued that the nun's commitment to Christian nonviolence was not a threat to the public. Rice wrote to Amul Thapar asking for leniency.
The judge was not moved and sentenced Rice to three years imprisonment, while Walli and Oertje Obed were each sentenced to more than five years.
The 6th U.S. The 6th U.S. Circuit Court of Appeals tossed out the sabotage accusation and the trio were released in May 2015, having served two years. Later, they were resentenced for a lesser charge of injuring property government property.
Rice testified during her jury trial and defended her decision "manufacturing that...can only lead to death" as an attempt to stop the production of uranium at Oak Ridge. According to a transcript, Rice was defending her actions.
She said that she had to make the decision to violate the law. "My guilt is that it took me 70 years to understand what I felt in my conscience."