(CNN) -- A 109,305-acre fire, mostly on the grounds of a U.S. Energy Department facility containing a nuclear fuel development complex, has been fully contained, according to the government's InciWeb fire incident information website.
The so-called Jefferson Fire, at the Idaho National Laboratory, about 40 miles west of Idaho Falls, had been burning since Tuesday afternoon, driven by winds up to 45 mph. The cause is still unknown.
InciWeb had said as of early Thursday afternoon, the fire was 60 percent contained. Sarah Wheeler, a Bureau of Land Management spokeswoman, confirmed the fire had burned a few hundred acres more while crews contained the final 40 percent of the blaze.
"That's hard to do working 10 miles of fire line," she said.
The 142 personnel on site planned on patrolling, mopping up and monitoring the situation Friday, the InciWeb site said.
About 80 percent of the charred land belongs to the Idaho National Laboratory, an applied engineering lab supporting the Energy Department's missions in nuclear and energy research, science and national defense.
During the fire, as a precautionary measure, the lab shut down power to the Materials and Fuels Complex, a nuclear research center, Wheeler said. That power has since been restored, she said.
CNN's Mark Morgenstein contributed to this report.