An 83-year-old Catholic nun is scheduled to be sentenced on Tuesday for breaking into the primary U.S. storehouse for bomb-grade uranium, SFGate.com reported.

Last year, Sister Megan Rice and two others -- Michael Walli and Greg Boertje-Obed -- were convicted of sabotage after performing a break-in of the nuclear weapons plant in Oak Ridge, Tennessee. All three will be sentenced at 9 a.m. Tuesday at the U.S. District Court in Knoxville.

The government recommended six to nine years in prison for each of them, according to the San Francisco Chronicle. They are also seeking $53,000 in restitution for damages, which included cutting fences and painting slogans and splattering blood on the walls.

However, all three are asking the court for leniency and claim their actions at the Y-12 National Security Complex were only meant to draw attention to America's stockpile of nuclear weapons, which they believe are immoral and illegal.

"These people have been committed peace and justice advocates for decades," defense attorney Bill Quigley said.

U.S. District Judge Amal Thapar did not grant their previous requests for leniency and ordered that all three defendants remain in jail until their trials finish.

"The defendants are entitled to their views regarding the morality of nuclear weapons. But the defendants' sincerely held moral beliefs are not a get-out-of-jail-free card that they can deploy to escape criminal liability," Thapar wrote in a ruling last October, denying their request for acquittal and a new trial.

Following their convictions, the defendants showed the court thousands of letters of support they've received from around the world.

"I think that is mostly because of Sister Rice," Quigley said. "She's very well loved and has lots of people praying for her and supporting her."

One of the letters showed in court came from Sister Katharine Holmstrom, a nun in London.

"Your court faces a great challenge -- making a careful distinction between persons who act in clear conscience, guided by a moral vision, and others whose actions may be self-serving or maleficent in nature," Sister Holmstrom wrote to Thapar. "In cases like these, the law is sometimes incapable of making such distinctions. The heavy burden of seeking a just disposition then falls to the jurist who will render a sentence."

A second letter read in court came from Sister Rice herself.

"As a defendant, I ask only that you allow your conscience to guide you," Rice wrote.