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 National Reactor Innovation Center (NRIC) wants to hear from developers and end users interested in integrated energy systems for advanced reactors. Battelle Energy Alliance (BEA), the managing and operating contractor for Idaho National Laboratory, has issued a call for Expressions of Interest for a potential multi-phase demonstration program for innovative uses of nuclear energy, to be carried out by NRIC and the Crosscutting Technology Development Integrated Energy Systems (CTD IES) program. The final date for responses is May 21.

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.

Many regions with peak potential hydrogen demand, as shown in this image created by the National Renewable Energy Laboratory and reproduced in the Hydrogen Program Plan, are also home to operating nuclear power plants. Image: NREL, The Technical and Economic Potential of the H2@Scale Concept within the United States

The Department of Energy released a Hydrogen Program Plan on November 12 that provides a strategic framework for the agency’s hydrogen research, development, and demonstration activities.

The DOE’s Offices of Nuclear Energy, Energy Efficiency and Renewable Energy, Fossil Energy, Electricity, and Science, and the Advanced Research Projects Agency–Energy are all working on the production, transport, storage, and use of hydrogen in several sectors of the economy and have developed technical and programmatic multi-year plans. The Hydrogen Program Plan coordinates and complements those efforts by presenting a strategic direction that highlights the importance of collaboration both within DOE and with stakeholders in industry, academia, and the states.

Two projects intended to accelerate the deployment of hydrogen production technology at existing U.S. light-water reactors received the bulk of the funding announced by the Department of Energy’s Office of Nuclear Energy (NE) on October 8 under the ongoing U.S. Industry Opportunities for Advanced Nuclear Technology Development funding opportunity announcement (FOA). Out of three projects with a total value of $26.9 million, the two involving hydrogen production have a total value of $26.2 million.

Three companies that are part of a larger collaboration to develop and demonstrate Natrium, the fast reactor design recently introduced by TerraPower and GE Hitachi Nuclear Energy (GEH), were invited to participate in a webinar hosted by ClearPath to talk about Natrium’s design, fuel requirements, and load-following potential.

The September 21 webinar, titled “Natrium: Latin for Sodium, Big for Advanced Nuclear,” was moderated by Rich Powell, executive director of ClearPath, and featured TerraPower’s Chris Levesque and Tara Neider, Centrus Energy’s Dan Poneman, and Duke Energy’s Chris Nolan.

A report just released from the Clean Energy Ministerial’s (CEM) Nuclear Innovation: Clean Energy (NICE) Future initiative examines the potential roles that flexible nuclear energy generation can play in both current and future clean energy systems.

A product of the initiative’s Flexible Nuclear Campaign for Nuclear-Renewables Integration, the 154-page report, Flexible Nuclear Energy for Clean Energy Systems, includes the views of experts from government agencies, ministries, and industry organizations across the globe.

The report uses the term “flexibility” to mean the ability of an energy source to economically provide services when and where they are needed by end users. Energy services can include both electric and nonelectric applications using both traditional and advanced nuclear power plants and integrated systems, according to the report.

An artist’s rendering of Natrium. Image: TerraPower

The Natrium reactor and energy system architecture, recently introduced by TerraPower and GE Hitachi Nuclear Energy (GEH), offers baseload electricity output from a 345-MWe sodium fast reactor with the load-following flexibility of molten salt thermal storage. Stored heat can be used to boost the system’s output to 500 MWe for more than five and a half hours when needed, according to TerraPower. A company representative told Nuclear News that the company expects a commercial Natrium plant to cost $1 billion or less.

This flowchart is housed in a library of Sankey diagrams at flowcharts.llnl.gov and is also available as a PDF. Source: Department of Energy/LLNL, based on EIA data

Every year, Lawrence Livermore National Laboratory releases flowcharts illustrating U.S. energy consumption and use. The flowcharts, called Sankey diagrams, allow scientists, analysts, and other decision makers to compare the contributions made by various energy sources, including nuclear power, and the end uses of those sources, including residential, industrial, commercial, and transportation markets. Taken as a series of annual snapshots, energy use trends and opportunities quickly become apparent.

This year, in addition to releasing the 2019 energy flowchart, the lab issued state-by-state energy flowcharts for 2015–2018 and carbon emissions charts for 2014–2017. It is currently at work on charts of international energy use that it hopes to release by the end of the year.

The Department of Energy is asking for input on an Energy Storage Grand Challenge (ESGC) Draft Roadmap and Request for Information (RFI) and recently extended the response deadline to August 31. While there is no “N” for nuclear in “ESGC,” nuclear is definitely part of the DOE’s plan for future energy storage technologies and integrated energy systems designed to improve the efficiency and reliability of U.S. energy markets. In fact, the House Energy and Water Appropriations Committee has called for $4 million in the Office of Nuclear Energy’s Fiscal Year 2021 budget to support energy storage.

The American Nuclear Society was formally accepted as a Nuclear Innovation: Clean Energy Future (NICE Future) initiative partner organization in January, joining ten countries and 14 partner organizations to direct the global conversation about the roles nuclear energy can play in clean energy systems of the future.