[10] The importance of these goals has led to proposals for competing projects in other countries, particularly the Hyper-Kamiokande experiment in Japan, scheduled to begin data-taking in 2027.

LBNF construction will include a 58-foot-high hill made of compacted soil, connecting to a 680-foot-long tunnel that will contain a 635-foot-long particle decay pipe.

[14] The hill is integral to the "improved tritium management [that is] a major focus on the design of this new, higher beam power facility.

"[15] Tritium produced by beamlines can enter the surface ground water, however rates at Fermilab are maintained at a level well below that allowed by regulations.

[17] The DUNE far detector design is based on state-of-the-art Liquid Argon Time Projection Chamber (LArTPC) technology.

The far detector will consist of a total volume of 70-kilotons of liquid argon located deep underground, 1.5 kilometers (4,850 ft) under the surface.

MicroBooNE is the longest continuously running LArTPC detector, having taken data from 2015 to 2021—considerably shorter than the time-period of 20 years expected for DUNE.

[28] The primary purpose is to monitor and characterize the beam as the neutrinos are created in the LBNF line, so as to make accurate predictions for interaction rates at the DUNE far detector.

[37] In August 2024, scientists detected the first neutrinos using a DUNE prototype particle detector at the U.S. Department of Energy’s Fermi National Accelerator Laboratory.

[40] At the time of CD-1R, the DOE required that if the projected baseline cost rise to exceed $2.79 billion, or 50% above the range’s upper bound, then CD-1R must be revisited---a situation that was already being realized by 2020.

[41] Due to a history of lower-than-requested congressional appropriations for the project, at the same November 2021 meeting, DOE presented a "conservative profile [for funding] that the Office of Science can support.

[44] To meet this cost, detector module 2 will be only 40% filled with liquid argon at project completion, and therefore not immediately usable for physics.

[49] Hyper-K is a 260 kton total volume detector under construction 295 km from the Japan Proton Accelerator Research Complex (J-PARC) neutrino source.

[50] Fermilab Director Merminga was confronted about the potential for DUNE to be scooped by the competition in a presentation to the House Science Committee in June 2022.

[51] In response, Merminga claimed that the projects are complementary, with DUNE providing more precise reconstructions of neutrino interactions due to the liquid argon technology than can be achieved in the water-based Hyper-K water detector.

In June 2021, plumes of dust rising from the Open Cut due to DUNE construction led to complaints from businesses, homeowners, and users of a nearby park.

[54] Complaints continued through spring 2022 without adequate response from Fermilab management, resulting in the South Dakota Science and Technology Authority shutting down excavation on March 31, 2022.

[55] An investigation ensued in which the Fermilab management team admitted to failures in protocols, and instigated new measures to prevent black dust from leaving the Open Cut.