While initial operation of MARVEL, a tiny microreactor that will be installed and operated inside Idaho National Laboratory’s Transient Reactor Test (TREAT) Facility, might not occur until 2025, testing of a nonnuclear prototype is now under way at the New Freedom, Pa., manufacturing facility of Creative Engineers, Inc. (CEI). The Department of Energy announced the start of prototype testing on September 20.
About PCAT: The 12-foot-tall, full-scale replica of the MARVEL microreactor is called PCAT, for “primary coolant apparatus test.” CEI installed PCAT in May and loaded the system with sodium-potassium and lead-bismuth coolants to demonstrate heat removal from its electrically heated core. The MARVEL team is now collecting data on the system’s temperatures and coolant flow to ensure that MARVEL will perform as expected. PCAT testing will unfold in phases and is initially focused on demonstrating critical heat removal via natural circulation, according to the DOE.
“The MARVEL project underscores the potential of human innovation to address pressing energy security and climate challenges facing modern society,” said Yasir Arafat, chief designer and project lead for MARVEL. “This PCAT demonstration is an important step in that process and will help validate and benchmark tools we use to accurately predict how the reactor will perform.”
About MARVEL: MARVEL will be a sodium-potassium–cooled microreactor that is expected to generate 85 kWt of power and be connected to INL’s “first nuclear microgrid.” It will be used to test microreactor applications, evaluate systems for remote monitoring, and develop autonomous control technologies, according to the DOE.
The MARVEL team is close to finalizing the reactor design and “is in discussion to procure key long-lead components for fabrication, such as Stirling engines and nuclear fuel,” according to the DOE.
Schedule shifts: The September 20 announcement of PCAT testing follows an assertion in a May 22 DOE announcement that PCAT testing “could begin as early as July.”
While the DOE has backed away from earlier estimates that MARVEL would be operating by the end of 2024 and is now saying that MARVEL “is targeting to be operational in 2025,” the September 20 press release does leave the door open to earlier operation, stating that “the reactor could be operational as soon as the end of next year.”
Regardless of startup in late 2024 or 2025, MARVEL could still be the first new reactor to operate at INL in more than four decades. Also in the running for that status is the Defense Department’s Project Pele. According to statements in early August from Project Pele program manager Jeff Waksman, if that project goes according to schedule, “we will be able to turn the reactor on before the end of calendar year 2025.”