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Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
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.
Joachim E. Geiger, Arthur Weller, Michael C. Zarnstorff, Carolin Nührenberg, Andreas Horst Franz Werner, Yaroslav I. Kolesnichenko, W7-AS Team, Neutral Beam Injection Group
Fusion Science and Technology | Volume 46 | Number 1 | July 2004 | Pages 13-23
Technical Paper | Stellarators | doi.org/10.13182/FST04-A536
Articles are hosted by Taylor and Francis Online.
One of the major goals for Wendelstein 7-AS (W7-AS) was the testing of the theoretical basis for the optimized configuration of Wendelstein 7-X (W7-X), currently under construction in Greifswald, Germany. In the last experimental campaign of W7-AS, volume-averaged values >3% have been achieved. The underlying experimental changes leading to these results are briefly reviewed. The equilibrium characteristics expected from magnetohydrodynamic (MHD) theory are modeled in a simplified picture and compared with three-dimensional equilibrium calculations. A wide range of parameters has been covered in the experiments with and without net toroidal currents. Experimental data are compared with free-boundary equilibrium calculations and exhibit good agreement. The high- equilibria usually showed only small MHD activity. The most prominent activities are low-frequency pressure-driven modes connected with low-order rationals also expected from numerical calculations using the CAS3D code, and Alfvén modes driven by energetic particles from the tangential neutral beam injection. Comparison of experimentally measured frequencies and mode structures from soft-X-ray tomography with theoretical predictions also shows the improving understanding of these modes in stellarators. The agreement of experiment and theory gives confidence in the predictions for W7-X.