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.
Idaho National Laboratory’s Transient Reactor Test Facility, also known as TREAT, returned to service in 2017 after a hiatus of more than two decades. To make full use of TREAT’s capabilities, researchers at INL created the Minimal Activation Retrievable Capsule Holder (MARCH) test vehicle system, which, according to an August 26 Department of Energy press release, can cut years off the development process for nuclear fuels and materials and allow new clients, like NASA, to take advantage of TREAT’s capabilities.
The Transient Reactor Test (TREAT) Facility at Idaho National Laboratory was restarted in 2018 after being in safe standby mode since 1994. The June 2020 issue of the American Nuclear Society's Nuclear Technology (NT) journal features seven technical papers related to the benchmarking of the facility. Wade Marcum, a lead researcher on the project and guest editor of June’s NT issue, explained, “The goal of this effort was to understand, to the best of our ability, the expected response of the TREAT reactor upon its restart.”