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2025 ANS Winter Conference & Expo
November 9–12, 2025
Washington, DC|Washington Hilton
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Latest News
NNSA awards BWXT $1.5B defense fuels contract
The Department of Energy’s National Nuclear Security Administration has awarded BWX Technologies a contract valued at $1.5 billion to build a Domestic Uranium Enrichment Centrifuge Experiment (DUECE) pilot plant in Tennessee in support of the administration’s efforts to build out a domestic supply of unobligated enriched uranium for defense-related nuclear fuel.
C. B. Yeamans, D. L. Bleuel
Fusion Science and Technology | Volume 72 | Number 2 | August 2017 | Pages 120-128
Technical Paper | doi.org/10.1080/15361055.2017.1320499
Articles are hosted by Taylor and Francis Online.
In need of a spatially resolved neutronic measurement to better understand the implosion physics of inertial-confined fusion, the National Ignition Facility (NIF) developed a distributed Flange-mounted Neutron Activation Diagnostic system (FNAD). FNAD measures primary deuterium-tritium (D-T) fusion neutron fluence at 20 points surrounding the target chamber using the 90Zr(n,2n)89Zr reaction, utilizing the 12.1-MeV reaction threshold to minimize signal from spurious neutron sources. Through careful design of the measurement systematics, the relative ratios of fluence at those 20 points are measured to within 2%. This precision is sufficient to allow interpretation of the resulting neutron sky as a map of scattering mass areal density (ρR) of the cold compressed D-T fuel surrounding the nuclear burn. Controlling the shape of this fuel during assembly is essential to achieving optimal implosion performance. This paper details the system design and locational deployment, measurement techniques, and calibration procedure. It also outlines data analysis and reduction, and data presentation methods used during the National Ignition Campaign and High-Foot Campaign.