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Atlanta, GA|Atlanta Marriott Marquis
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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.
Ezio Bittoni, Marcel Haegi
Fusion Science and Technology | Volume 22 | Number 4 | December 1992 | Pages 461-469
Alpha-Particle Special | doi.org/10.13182/FST92-A30081
Articles are hosted by Taylor and Francis Online.
The diffusion coefficient for the fast alpha particles produced in a thermonuclear plasma is derived numerically for the case of a magnetic field perturbed by ripple and magnetohydrodynamic (MHD) helical modes. It is found that this diffusion coefficient varies monotonously with the amplitude of the magnetic perturbations and that the transition from the classic to the stochastic regime occurs smoothly. The ripple perturbations as well as the MHD perturbations essentially affect the trapped-particle orbits. It is shown that above an MHD perturbation amplitude of some 10−3 of the total magnetic field, severe fast alpha-particle losses must be expected. Parametric studies have shown the dependence of the MHD helical diffusion coefficient on the amplitude of the perturbation, the helical mode number, and the energy of the alpha particles. An analytic expression for the MHD diffusion coefficient, based on these scalings, is proposed.
