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Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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Fusion Science and Technology
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Deep Space: The new frontier of radiation controls
In commercial nuclear power, there has always been a deliberate tension between the regulator and the utility owner. The regulator fundamentally exists to protect the worker, and the utility, to make a profit. It is a win-win balance.
From the U.S. nuclear industry has emerged a brilliantly successful occupational nuclear safety record—largely the result of an ALARA (as low as reasonably achievable) process that has driven exposure rates down to what only a decade ago would have been considered unthinkable. In the U.S. nuclear industry, the system has accomplished an excellent, nearly seamless process that succeeds to the benefit of both employee and utility owner.
J. A. Snipes, N. Basse, P. Bonoli, C. Boswell, E. Edlund, A. Fasoli, R. S. Granetz, L. Lin, Y. Lin, R. Parker, M. Porkolab, J. Sears, V. Tang, S. Wukitch
Fusion Science and Technology | Volume 51 | Number 3 | April 2007 | Pages 437-450
Technical Paper | Alcator C-Mod Tokamak | doi.org/10.13182/FST07-A1431
Articles are hosted by Taylor and Francis Online.
Energetic particle physics is studied in Alcator C-Mod in reactor relevant regimes with high density and equilibrated electron and ion temperatures. Stable Alfvén eigenmodes are excited with low-power active magnetohydrodynamic antennas in the absence of a significant energetic particle tail to directly measure the damping rate of the modes. Stable toroidal Alfvén eigenmode (TAE) damping rates between 0.5% < / < 4.5% have been observed in diverted and limited plasmas. Alfvén eigenmodes are destabilized with high-power hydrogen minority ion cyclotron radio frequency (ICRF) heating (PICRF < 6 MW) in lower-density plasmas in the current rise and in relatively high-density ([bar]ne < 2.5 × 1020 m-3) H-mode plasmas, which creates an energetic hydrogen ion tail with calculated energies up to 400 keV. Low toroidal mode number (n < 4) unstable modes are observed in the current rise with magnetic pickup coils at the wall and phase contrast imaging density fluctuation measurements in the core. Observations of energetic particle modes or TAEs that decrease in frequency and mode number with time up to a large sawtooth collapse indicate that fast particles play a role in stabilizing sawteeth. Alfvén eigenmodes can also be used as diagnostics to precisely constrain the q profile and provide a qualitative measure of the fast particle distribution time evolution.
