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The deadline arrives: Checking in on the Reactor Pilot Program
On May 23, 2025, President Trump signed Executive Order 14301, “Reforming Nuclear Reactor Testing at the DOE,” which instructed the Department of Energy to create a Reactor Pilot Program (RPP)—a new system in which companies could pursue DOE authorization to build and test their first-of-a-kind nuclear technologies. EO 14301 set an ambitious goal for that program: three reactors achieving criticality by July 4, 2026.
B. R. Wienke, R. E. Seamon, D. G. Madland
Nuclear Science and Engineering | Volume 113 | Number 1 | January 1993 | Pages 86-92
Technical Note | doi.org/10.13182/NSE93-A23996
Articles are hosted by Taylor and Francis Online.
Antiprotons are negatively charged protons that continuously slow down in matter until they are stopped and captured on the surface of a nucleus by a proton; in which case, both proton and antiproton annihilate into gammas, pions, and other short-lived particles. When an antiproton annihilates at rest on the surface of an actinide nucleus, such as uranium, many fragments and neutrons are also produced, following direct reaction, nuclear evaporation, and fission processes, along with production of high-energy gammas and pions. Collectively, these processes have been termed antiproton fission, for simplicity, because many neutrons are produced as the end result of all reactions. Recent experiments at CERN suggest that as many as 15 to 20 neutrons are emitted following antiproton annihilation on 238U, that their distribution is peaked near 5 MeV in energy, and that a sizeable fraction (45 to 75%) of the annihilation energy (1.88 GeV per annihilation) is deposited locally in the 23SU. A fit to the experimental neutron spectrum of Angelopoulos et al. is presented, and the systematics of transporting and annihilating antiprotons in a multigroup representation are investigated for the first time. Applications of antiproton transport and fission in small spherical assemblies are discussed and contrasted, mainly systematics of local and nonlocal antiproton annihilation, criticality, and disassembly.