Anti-nuclear activists Gregory Boertje-Obed, Sister Megan Rice, and Michael Walli are shown in Knoxville, Tenn., in February of 2013. (Linda Davidson/The Washington Post)

Three peace activists who intruded onto a nuclear weapons site in July 2012 were sentenced Tuesday to 35 months or 62 months in prison by a federal judge, three weeks after he ordered them to pay $53,000 in restitution for damaging the site’s security systems and defacing a storage facility that contains the United States’s stockpile of weapons-grade uranium.

“If all that energy and passion was devoted to changing the laws, perhaps real change would’ve occurred by today,” said U.S. District Judge Amul Thapar, after praising the three for their consciences and good works. The judge, who imposed sentences that were lower than what the government requested, said that perhaps the threat of significant jail time “will lead people back to the political process I fear they’ve given up on.”

Catholic nun Megan Rice, 84, received a sentence of two years and 11 months. Vietnam veteran and self-described Catholic layman Michael Walli, 65, of Washington, D.C., and house painter Gregory Boertje-Obed, 58, of Duluth, Minn., each received five years and two months. Each prison sentence will be followed by three years of supervised release. They have all reserved the right to appeal their sentences.

The activists have each served 81 / 2 months in prison while awaiting sentencing. Walli and Boertje-Obed have served prison time for similar crimes that they characterize as symbolic disarmament actions and civil resistance against a far greater crime: the maintenance of a stockpile of immoral and costly weapons that violate international law.

The three activists, who call themselves “Transform Now Plowshares,” were convicted in May of intending to harm national security and damaging more than $1,000 in government property at the Y-12 National Security Complex, a nuclear weapons plant in Oak Ridge, Tenn., 30 minutes west of Knoxville.

PostTV sat down to talk with Sister Megan Gillespie Rice in April 2013, before she headed to Tennessee to face trial. (The Fold/The Washington Post)

In the pre-dawn hours of July 28, 2012, they hiked a wooded ridge, cut through four fences, and splashed human blood and spray-painted biblical messages on the outside of the building that warehouses an estimated 400 tons of highly enriched uranium — enough to fuel 10,000 nuclear bombs.

On Tuesday, more than 100 supporters filled two courtrooms at U.S. District Court in downtown Knoxville. This continuation of the sentencing hearing, interrupted and delayed last month by snow, focused mainly on the judge’s struggle to reconcile sentencing guidelines with the character and personal history of the activists.

The guidelines do “not distinguish saboteurs who truly mean harm from peace protesters who intend change,” Thapar said before sentencing, which came after nearly five hours of arguments, including final statements from Rice, Walli and Boertje-Obed.

“I was acting in support of the rule of law with my actions,” said Walli, who added: “I am the face of tomorrow. The face of demilitarization and vindication of the prophets.”

Boertje-Obed read an excerpt from a speech by Martin Luther King Jr., and he said that if the United States would abide by the Nuclear Non-Proliferation Treaty it “would promote respect for the law.”

Rice cited poverty and economic disparity as “the direct fallout from gross spending to maintain a nuclear industrial complex.”

“Please have no leniency with me,” the nun told the judge. “To remain in prison for the rest of my life would be the greatest honor for me.”

Then, with the judge’s permission, she led people in the courtroom in a short song. “Sacred the Earth, sacred the waters, sacred the sky,” they sang.

The unprecedented intrusion shut down operations at the site for two weeks, led to four congressional hearings and exposed a glitch-ridden security system that cost $150 million a year. The National Nuclear Security Administration, a semiautonomous agency within the Energy Department, responded to the break-in with a variety of security measures, from installing 2,850 linear feet of concertina wire to requiring that malfunctioning security tools be repaired within 24 hours.

Babcock & Wilcox Technical Services Y-12, the site’s private contractor for management and operations, was docked $12.2 million in fees and lost a 10-year contract worth $23 billion to manage both Y-12, where uranium is stored and processed, and the Pantex Plant in Amarillo, Tex., where nuclear weapons are assembled and disassembled.

B&W Y-12 is still managing Y-12, pending a ruling — due Feb. 28 — by the Government Accountability Office on the contractor’s appeal. WSI Oak Ridge, which provided the security guards at the site, lost its subcontract two months after the break-in.