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Breaking ground on a new approach to construction
The drive to Kairos Power’s reactor demonstration site in Oak Ridge, Tenn., is not only scenic—it’s historic. Nearly 85 years ago, roughly 30,000 construction workers transformed orchards and farmland into a key Manhattan Project site. Depending on your route, you may pass by one of the three gatehouses that were once military checkpoints controlling access to Atomic Energy Commission production facilities.
C. E. Ragan III, G. F. Auchampaugh, A. Hemmendinger, M. G. Silbert
Nuclear Science and Engineering | Volume 61 | Number 1 | September 1976 | Pages 33-39
Technical Paper | doi.org/10.13182/NSE76-A28458
Articles are hosted by Taylor and Francis Online.
A benchmark measurement of the neutron leakage spectrum from a pulsed 38-kg uranium (93.5% 235U) sphere has been made using time-of-flight techniques. The sphere had a multiplication of ∼11 for 14-MeV neutrons, and a neutron hold-up time of ∼40 nsec. The centrally located source of 14.1 ± 0.8-MeV neutrons, produced by bombarding a tritium gas target with pulses of low-energy deuterons, was isotropic to ±7.7%. Neutrons in the 0.180- to 16.0-MeV energy range were detected at the end of a 39-m flight path by an Ne-213 liquid scintillator employing pulse-shape discrimination. The detector efficiency was measured over this same energy range using monoenergetic neutrons from the T(p,n) T(d,n), and D(d,n) reactions. The measured neutron flux as a function of energy is compared with the results of Monte Carlo calculations performed with the MCN code. Uranium cross sections from ENDF/B-IV and an older set from Lawrence Livermore Laboratory were used in these calculations. The results calculated using the ENDF/B-IV cross sections are in good agreement with the measurements, especially in the 1- to 6-MeV energy region where the uncertainties in both the calculated and experimental results are the smallest.