The Department of Energy announced February 7 that fuel for the MARVEL microreactor, which Idaho National Laboratory plans to host inside the Transient Reactor Test (TREAT) facility, is now being fabricated by TRIGA International, with the first fuel delivery expected in spring 2025. MARVEL operation was expected “by the end of 2024” as recently as May 2023, but that timeline had shifted by October, when the DOE said MARVEL “is expected to be completed in early 2025.” Now, according to the DOE’s latest announcement, “Fuel loading for MARVEL is anticipated to occur in 2026, with the microreactor expected to be on line by 2027.”

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.

As global concerns about climate change and energy sustainability intensify, the need for cleaner and more efficient energy sources is more critical than ever. Nuclear power consistently emerges as an important part of the solution, driving the development of innovative technologies. While numerous fission technologies were built and proven in the early days of nuclear energy, times and regulations have changed. Between the 1950s and mid-1970s, Idaho National Laboratory built 52 reactors—then paused for five decades. Can this nation return to the frontier once again, embarking on new fission technologies? With a mature regulatory environment and increasing public support, how quickly can a new non–light water system be deployed in modern times?

An electric-powered prototype of MARVEL, the tiny microreactor designed and planned for operation inside the Transient Reactor Test (TREAT) facility at Idaho National Laboratory, has successfully been installed at a manufacturing facility in Pennsylvania ahead of a testing program that could begin as early as July, the Department of Energy announced on May 22.

The Department of Energy’s commitment to breaking down market barriers with initiatives, programs, and access to facilities is making it simpler and more efficient than ever for industry to partner with national laboratories. It is especially timely, as the country continues to face evolving security, economic, and clean energy challenges. Partnering opportunities via the DOE’s Cooperative Research and Development Agreements (CRADAs) and Strategic Partnership Projects (SPPs) are particularly prevalent in the commercial nuclear community and have seen a tremendous amount of funding and support dedicated to advancing the development, demonstration, and deployment of new reactor technologies.

From refugee in Bangladesh to top nuclear engineer at Idaho National Laboratory, ANS member Yasir Arafat has led quite an interesting life, as described in a recent online profile written by Donna Kemp Spangler for the INL website. Arafat is leading the development of the Department of Energy’s Microreactor Applications Research Validation and EvaLuation (MARVEL) project at INL. The profile notes that MARVEL, which Arafat envisioned soon after joining INL in 2019, is scheduled to be “built and demonstrated at INL’s Transient Reactor Test Facility and connected to the world’s first nuclear microgrid within two years.”

A full-scale, electrically heated prototype for the Department of Energy’s Microreactor Applications Research Validation and Evaluation (MARVEL) project was fabricated in just nine months, according to an article published by Idaho National Laboratory on January 31. The article explains in part how a team from the lab’s machine shop created the prototype.

The definition of a microreactor is ambiguous. But whether your upper cutoff is 10 MW or 20 MW, the Microreactor Applications Research Validation and Evaluation (MARVEL) reactor that the Department of Energy plans to build is, at 100 kW, on the tiny side of micro.

The Department of Energy’s Office of Nuclear Energy is spreading the word about plans to build a tiny microreactor called the Microreactor Applications Research Validation & EvaLuation (MARVEL) project inside Idaho National Laboratory’s Transient Reactor Test (TREAT) Facility and have it in operation within the next three years. INL recently released a video that describes how MARVEL could help researchers and industry partners test, develop, and demonstrate the integration of a microreactor’s heat and electricity output with other technologies.

The Department of Energy launched a 14-day public review and comment period on January 11 on a draft environmental assessment for a proposal to construct the Microreactor Applications Research Validation & EvaLuation (MARVEL) project microreactor inside Idaho National Laboratory’s Transient Reactor Test (TREAT) Facility.

The basics: The MARVEL design is a sodium-potassium–cooled thermal microreactor fueled by uranium zirconium hydride fuel pins using high-assay, low-enriched uranium (HALEU). It would be a 100-kWt reactor capable of generating about 20 kWe using Stirling engines over a core life of about two years.

The DOE proposes to install the MARVEL microreactor in a concrete storage pit in the north high bay of the TREAT reactor building. Modifications to the building to accommodate MARVEL are anticipated to take five to seven months. Constructing, assembling, and performing preoperational testing are expected to take another two to three months prior to fuel loading.