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Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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DOE issues new NEPA rule and procedures—and accelerates DOME reactor testing
Meeting a deadline set in President Trump’s May 23 executive order “Reforming Nuclear Reactor Testing at the Department of Energy,” the DOE on June 30 updated information on its National Environmental Policy Act (NEPA) rulemaking and implementation procedures and published on its website an interim final rule that rescinds existing regulations alongside new implementing procedures.
B. Juste, R. Miró, G. Verdú, S. Díez, J. M. Campayo
Nuclear Technology | Volume 175 | Number 1 | July 2011 | Pages 175-181
Technical Paper | Special Issue on the 16th Biennial Topical Meeting of the Radiation Protection and Shielding Division / Radiation Transport and Protection | doi.org/10.13182/NT11-A12287
Articles are hosted by Taylor and Francis Online.
Megavoltage sources are commonly used in radiotherapy treatments, and the determination of the spectral distribution of a photon beam is extremely important for exact dosimetry and for the calculation of therapeutic dose distributions. Since direct measurements of the spectrum are very difficult, we present a technique to accurately calculate the bremsstrahlung spectra based on a numerical reconstruction upon central-axis depth dose data measured in a water tank using inverse methods.The basic idea of this technique is that the measured depth dose curve can be expressed as a weighted superposition of monoenergetic depth dose curves. While traditional approaches directly use the measured depth dose data, we show the improvement of using the gradient of these data for reconstruction. The inverse problem in terms of gradients is shown to be markedly less ill-conditioned than the usual inverse problem. In each case, a Tikhonov regularization is introduced to minimize the effects of noise due to measurement and computation. We illustrate this theory to calculate a 6-MeV photon beam from an Elekta Precise radiotherapy unit utilizing the gradient of depth dose measurements in a water tank.