NEW YORK — She has been arrested 40 or 50 times for acts of civil disobedience and once served six months in prison. In the Nevada desert, she and other peace activists knelt down to block a truck rumbling across the government’s nuclear test site, prompting the authorities to take her into custody.
She gained so much attention that the Energy Department, which maintains the nation’s nuclear arsenal, helped pay for a lengthy oral history in which she described her upbringing and the development of her antinuclear views.
Now, Sister Megan Rice, 82, a Roman Catholic nun of the Society of the Holy Child Jesus, and two male accomplices have carried out what nuclear specialists call the biggest security breach in the history of the nation’s atomic complex, making their way to the inner sanctum of the site where the United States keeps crucial nuclear bomb parts and fuel.
With flashlights and bolt cutters, the three pacifists defied barbed wire as well as armed guards, video cameras, and motion sensors at the Oak Ridge nuclear reservation in Tennessee early on July 28. They splashed blood on the Highly Enriched Uranium Materials Facility — a new , half-billion-dollar plant encircled by enormous guard towers — and hung banners outside its walls.
The actions of Rice, a New York native who grew up in Morningside Heights, and her cohorts are a huge embarrassment for President Obama. Since 2010, he has led a global campaign to eliminate or lock down nuclear materials as a way to fight atomic terrorism.
In interviews, Rice discussed her life and emphasized what she called ‘‘the issue.’’
‘‘It’s the criminality of this 70-year industry,’’ she said. ‘‘We spend more on nuclear arms than on the departments of education, health, transportation, disaster relief, and a number of other government agencies that I can’t remember.’’
Federal prosecutors, needless to say, take a different view.
‘‘This is a matter of national security,’’ William C. Killian, a US attorney.
Megan Gillespie Rice was born in Manhattan on Jan. 31, 1930, the youngest of three girls in a Catholic family.
Rice went to Catholic schools in New York, became a nun at 18, and received degrees in biology from Villanova and Boston College, where her studies included class work at Harvard Medical School on how to use radioactive tracers. From 1962 to 2004, with occasional breaks, she served her order as a teacher in Nigeria and Ghana.
While visiting Manhattan in the early 1980s, she joined in antinuclear protests.
Late last month, Rice set her sights on the Oak Ridge nuclear reservation. Her aim was to draw attention to its work.
On Thursday in Knoxville, federal prosecutors charged Rice, Michael R. Walli, 63, of Washington, and Gregory I. Boertje-Obed, 57, of Duluth, Minn., with trespassing on government property (a misdemeanor) as well as its destruction and depredation (both felonies). All pleaded not guilty.