Versatility, leadership, and “the highest fast neutron flux in the history of ever”: Highlights from INL’s VTR webinar

November 2, 2020, 12:04PMNuclear News

Clockwise from top left are Craig Piercy, Ray Furstenau, Tom O’Connor, Sean McDeavitt, Tara Neider, and Judi Greenwald.

The Versatile Test Reactor’s conceptual design was approved in September, and a draft environmental impact statement could be released within the week. The completion of more project milestones leading to operation in 2026, however, will depend on congressional appropriations. An expert panel described the need for a state-of-the-art test reactor and the value that the VTR could bring to the U.S. nuclear R&D community over its 60-year lifetime during a recent webinar—“Advanced U.S. Nuclear Research and Development: A Briefing and Discussion on the VTR”—hosted by Idaho National Laboratory.

Craig Piercy, ANS executive director/CEO, moderated the webinar, introducing a project update from VTR executive director Kemal Pasamehmetoglu and facilitating a Q&A session with representatives of the Nuclear Regulatory Commission, the Department of Energy, universities, reactor developers, and the Nuclear Innovation Alliance. A recording of the October 29 webinar is available online. INL also has a video and information online on the VTR.

“I think that the VTR represents part of a larger effort to modernize our infrastructure, develop a new set of technologies, and really preserve our global leadership in the field,” said Piercy. Read on to learn more about the promise the VTR holds for the nuclear community.

The latest plans: Pasamehmetoglu briefed the audience on near-term plans for the VTR. A record of decision expected in the summer of 2021 would include site selection for both the VTR (at INL or Oak Ridge National Laboratory) and fuel fabrication facilities. The VTR represents a substantial R&D investment both in terms of time and talent from six national labs, 19 universities, and 10 industry partners, and in terms of funding. Costs are estimated at $3.6 billion, with upper and lower bounds of $5.8 billion and $2.6 billion, respectively.

The 300-MWt, pool-type, sodium-cooled reactor based on GE Hitachi Nuclear Energy’s PRISM will have a core optimized by Argonne National Laboratory to produce neutrons, not power. A “rabbit” will allow rapid removal and placement of experiments while the reactor is running, and a flexible testing environment allows the insertion of cartridge loops to permit simultaneous testing in sodium, lead, lead-bismuth eutectic, helium, and salt environments. “We can use up to five loops that can operate simultaneously inside the sodium pool,” Pasamehmetoglu explained.

“We’re trying to create a world-premiere fast-spectrum test reactor with access by the technology developers, commercial developers, as well as scientists from all over the nation and possibly from certain parts of the world as well,” Pasamehmetoglu said. “This is, in my opinion, the last missing piece in our research and development infrastructure for us to reestablish U.S. global leadership and sustain that leadership.”

Ray Furstenau: The Nuclear Regulatory Commission’s director of nuclear regulatory research spoke about the role of the VTR from a licensing perspective.

On a memorandum of understanding signed by the DOE and the NRC in September 2019: “It really allows us the opportunities to benefit from what’s going on with the VTR. It gives us the opportunity to understand how the DOE is reviewing and authorizing the VTR that will help us as we see licensing actions on advanced technologies. The data that comes out of it will be so important to help us validate our codes.”

He added, “We’re doing [subsequent license renewals] as we speak for the current fleet . . . a machine like the VTR will provide information on material aging that we might not be able to get otherwise, so it is important to the current fleet.”

Judi Greenwald: Greenwald, executive director at the Nuclear Innovation Alliance, said that her organization’s mission is to accelerate innovation and commercialization of advanced nuclear power so that it can be part of the solution for climate change.

Cost-shared funding is limited, and for many advanced reactor developers “VTR provides . . . a platform for testing their technology, creating a more level playing field for innovation. . . . We need to innovate as fast as possible. [The VTR] is less of an innovation in and of itself than it is an enabler of innovation.”

She noted, “There is enormous potential for the advanced reactor designs to be more cost competitive, to fit better into a power sector that needs smaller increments of power; more flexible increments of power.”

Sean McDeavitt: A professor at Texas A&M University, McDeavitt is also part of the VTR experiment development team and a principal designer of the rabbit system.

“The [nuclear industry’s] growth prospects come from advanced reactors and advanced modifications of existing designs, all of which require access to real neutrons in real environments. You wind up having a lot of good ideas stop, or run into a brick wall, until they can get testing facilities to get the data they need.”

McDeavitt continued, “We’re in a position where, assuming we succeed and build the VTR, we have the highest fast neutron flux in the history of ever. You have the ability to manipulate it to where you need it, depending on gaps, shielding, thermalization . . . to enable the testing you want. Versatility is the word of the day here. We’re trying to build something that’s versatile enough, and part of being versatile enough is having enough fast neutrons to start with, that if you need to dial it in to something else, you can design your experiment appropriately.”

He concluded, “Something like [the VTR] to excite the next generation of nuclear engineers and scientists is invaluable . . . to give them a vision of the future, that we’re actually going somewhere with nuclear technology.”

Tara Neider: TerraPower’s senior vice president for program development and lab facilities talked about testing needs for the two fast reactor designs that TerraPower is working on—Natrium, which was recently awarded cost-share funding through the Advanced Reactor Demonstration Program, and a molten chloride fast reactor.

While much is already known about sodium reactors, “Our real innovation on Natrium is to make that reactor as economical as possible. And to get that economy, you need to do testing. . . . We won’t get the economics that we need if we don’t have the VTR,” she said.

TerraPower did some irradiation testing in Russia’s BOR-60 fast research reactor but terminated those tests before they were completed. “We don’t want to rely on Russia for our testing needs,” Neider said. Nor can TerraPower rely only on testing performed in its own laboratory. “The testing in a reactor needs to be done at the national lab level.”

Lacking testing facilities, “With Natrium, we decided to start with qualified fuel rather than jump into advanced fuel right away,” she said. “It slows us down, not having a test reactor. It would be a much slower process, if we don’t have the VTR, to get any improvements in our fuel and our materials.”

Tom O’Connor: O’Connor serves as the DOE’s federal program director for the VTR.

“For the past 50-some odd years, the [Advanced Test Reactor] at INL has been providing irradiation capabilities in the thermal spectrum. . . . Moving to the VTR, it’s important for development of fuels and materials and instruments and sensors; we haven’t had this capacity in over 25 years,” he said

“VTR is not an R&D project itself, it is a tool,” O’Connor noted. “In order to ensure we can bring this reactor online as quickly as possible, at as low a cost as possible, as a machine that will operate reliably, we are using proven technology.”

In addition to demonstrating advanced reactor licensing strategies and reinvigorating the supply chain, the VTR is “utilizing integrated digital engineering to control the design and the construction effectively,” he said. “It’s a digital twin that’s not only going to support us in the design and construction, but also long-term operations.”

O’Connor concluded, “At the end of the day innovation isn’t something that’s one and done. Innovation is something that’s going to be key to U.S. leadership in the nuclear industry for the next 60 years, and VTR has to be part of that.”

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