ORNL Director Streiffer visits MPEX as project enters new phase
Tucked away in a corner of the ORNL campus, construction and assembly of the Material Plasma Exposure eXperiment, or MPEX, continues at a steady pace. Once complete, MPEX will be a one-of-a-kind, world-leading scientific resource that will help answer some of the most pressing questions in plasma-material interactions and inform the future direction of fusion energy research.
To make fusion power a sustainable and efficient energy resource, components inside a reactor need to withstand extreme conditions for extended periods, with temperatures hotter than the core of the sun, powerful magnetic fields and constant bombardment by high-energy neutrons that can alter materials on the atomic level. The MPEX device will replicate the high-heat and magnetic fluxes of a fusion plasma and allow researchers to study how different materials respond and how material byproducts impact plasma stability. With the information gathered from MPEX, researchers and engineers will be able to optimize materials to better endure fusion conditions as they design the next generation of fusion energy devices.
A 3D-printed model of the completed MPEX device, in front of its future home. Photo: Carlos Jones
Lab director visits MPEX site. Laboratory Director Stephen Streiffer visited the MPEX site for the first time in early July, accompanied by the Fusion & Fission Energy & Science Directorate, Fusion Energy Division and MPEX leadership team.
Stephen toured the construction site, spoke with scientists and engineers working on the project, and learned more about the science behind MPEX and other cutting-edge work being done by the ORNL’s Fusion Energy Division.
Top row: FES Research Programs Manager Phil Snyder and MPEX interim project director John Sanseverino welcome Lab Director Stephen Streiffer to MPEX with the proper PPE for their tour. Second row: (L) Former MPEX project director Phil Ferguson shows Stephen a 3D model of the device and its components, (R) MPEX chief scientist Juergen Rapp explains the science behind plasma-material interactions in fusion reactors. Photos: Carlos Jones, layout: Sean Simoneau
Construction and assembly milestones achieved. With construction and device assembly now more than 60 percent complete, the MPEX site is almost unrecognizable from how it looked a year ago. The Multiprogram High Bay Facility in Bldg. 7625, which houses the MPEX project, was cleared out to make room for the device and associated facilities, and what was once a small parking lot at the side of the building now houses the cooling towers and electrical infrastructure that will support the device’s operation.
Earlier this year, the MPEX Sample Analysis Room went from a bare patch of concrete to an entire structure clad in protective magnetic shielding. The Sample Analysis Room will house the diagnostics equipment used to analyze material samples on-site after plasma exposure in the device. MPEX facilities subcontractor Day & Zimmermann encased the walls and floor of the 400-square-foot space with panels of Super Alloy 49, an alloy of iron and nickel with a specially controlled composition that makes it ideal for magnetic shielding applications. The shield panels will help protect the sensitive equipment from the powerful magnetic fields generated by the nearby MPEX device.
The MPEX Sample Analysis Room shielding progress, from the floor panels (left), to the walls (middle), and the completed room (right) which will protect the diagnostics equipment from the magnetic fields of the MPEX experiment.
Crews also began constructing the device’s support structure and installation fixtures in the basement of Bldg. 7603 in late spring. The structure forms the foundation for the entire 65-ton MPEX device, including the superconducting magnets, and features a sliding track of linear bearings that will allow engineers to more easily connect, access and maintain the subassemblies once they are installed.
The first MPEX support structure assembly was carefully transported, hoisted and lowered into the device installation pit in Building 7625 at ORNL’s Fusion Energy Campus. Photos: Kase Clapp and Genevieve Martin
Once assembly was complete, they faced the daunting task of lifting the eight-ton steel structure from the basement and transporting it to its final home in the high bay in Bldg. 7625. Thanks to a cross-directorate team of design engineers and hoisting and rigging crews, the first piece of the structure was successfully lifted by crane from the basement pit, loaded onto a truck for transit, then re-lifted and mounted in place. The full support structure installation is on track to be completed this month. Aftab Hussain, MPEX Lead Engineer, expressed special recognition and thanks to Matt Dessel, Ray Gardner III and his team, and Brad Sexton and his hoisting and rigging crew for safely and successfully completing the support structure assembly installation. — Sean Simoneau
The first device support structure assembly installed in 7625 at ORNL’s Fusion Energy Campus.
Photo: Kase Clapp and Genevieve Martin