“This is the closest that neutrino physicists have been able to get to a commercial reactor core,” said Juan Collar, a UChicago particle physicist who led the research at Dresden. “We gained unique experience in operating a detector under these conditions, thanks to Constellation’s generosity in accommodating our experiment.”
In a February 24 news release, UChicago said the researchers are planning to take more measurements using the technique, which may have applications in nuclear nonproliferation. According to UChicago, detectors could be placed next to reactors as a safeguard to monitor whether the reactor is being used for energy production or to make weapons.
Tiny detector: Neutrinos are sometimes called “ghost particles” because they pass invisibly through almost all matter, making them extraordinarily difficult to detect. Typically, large facilities containing massive tanks filled with detecting fluids have been used to search for neutrino signals. Collar, however, previously led a team at UChicago that built a 4- by 13-inch detector that weighs only 32 pounds, small enough to be placed in the reactor building at Dresden. Nuclear power reactors generate an especially high concentration of neutrinos, a rarity on earth.
Collar and his team had tested their tiny detectors at Oak Ridge National Laboratory in Tennessee, where they were able to carefully control much of the environment in order to get a good signal. But for the detector to work at Dresden, they had to build a new version adapted to deal with the much noisier environment of an operating commercial reactor.
“You’re getting radiation, heat, vibration from the turbines, radio-frequency noise from the pumps and other machinery,” Collar said. “But we managed to work around all the challenges that were thrown our way.”
They designed the detector with a complex multilayered shielding to protect it from other stray particles that would contaminate the data. Eventually, they were able to leave the detector in place to function unattended for several months, taking data all the while.
According to UChicago, the team next hopes to collect data at Constellation’s Braidwood nuclear power plant, about 15 miles south of Dresden, or at the Vandellòs nuclear plant in coastal Spain.
