The U.S. Nuclear Regulatory Commission has licensed Purdue University Reactor Number One (PUR-1), which the university said is the first entirely digital nuclear reactor instrumentation and control system in the country.
The reactor and facility, originally built in 1962, could aid the widespread implementation of digital technology in both research and industry reactors.
Clive Townsend, supervisor for Purdue's reactor, said, “We’re going from the vacuum tubes and hand-soldered wires of the ’60s, to LEDs, ethernet cables and advanced electronics.”
Traditional analog consoles make it difficult to take research data accurately and quickly, the university said. A digital system allows values to be measured instantly and means that more data can be processed and analyzed. Capabilities that may be possible include predictive analytics, machine learning and artificial intelligence.
Purdue's reactor is licensed to produce up to 1 kilowatt of thermal power, roughly the energy demand of a hair dryer or a toaster. The reactor's core is 2 ft3 in volume and sits at the bottom of a 17 ft deep cooling pool of water that measures 8 ft in diameter. This allows the core to be viewed while it is operating.
Fuel conversion
The PUR-1 originally used highly enriched, or "weapons-grade," uranium as fuel. In 1982, the government began to convert civilian reactors to low-enriched uranium. Conversion of the Purdue reactor was completed in 2007.
Over the years, the NRC has been deliberate in considering and approving digital control equipment in the nation's fleet of nuclear generating stations. Many control rooms at commercial reactors continue to feature banks of analog controls, displays and switches.
Purdue developed and built the digital system along with Mirion Technologies and the Curtiss-Wright Corp.Â
The digital conversion of PUR-1 began in 2012, when the U.S. Department of Energy awarded Purdue a grant through its Nuclear Energy University Program to replace reactor equipment with an upgraded instrumentation and control system.Â
German components
Some of the parts included in the NRC approval are certified under the German Nuclear Safety Standards Commission (KTA), rather than domestic U.S. standards. Historically, the NRC has accepted only parts certified under domestic standards, which Purdue said are generally cost-prohibitive for use. The NRC accepted the German-certified parts through the agency’s initiative for a "risk-informed and performance-based" regulatory process.
 “The fact that the NRC is accepting a digital console for a small research reactor, with parts certified under the KTA standards, signals the regulatory body moving toward approval in a large industry reactor,” Townsend said.
The university said that its digital reactor may offer several benefits both to industry players and educational settings. As a cyberphysical test bed, collaborators and corporate partners will be able to evaluate simulations of industry reactors using Purdue’s facility as a model and apply lessons learned and best practice improvements to their own reactors.
“Testing code and simulations in smaller university facilities allows more flexibility, ease of access and quicker development cycles than would be available at larger industrial partners,” said Robert Bean, the PUR-1 facility director and an assistant professor of nuclear engineering at Purdue. “At low cost, researchers will be able to quickly evaluate their work and achieve full-scale deployment.”
Digital technology also means that Purdue can use the reactor to send live data to remote locations, helping researchers match reactor status in real time to experimental results, and students to visualize from their monitors how a reactor responds.