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Conference Spotlight
Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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The Standards Committee is responsible for the development and maintenance of voluntary consensus standards that address the design, analysis, and operation of components, systems, and facilities related to the application of nuclear science and technology. Find out What’s New, check out the Standards Store, or Get Involved today!
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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.
C. C. Tsai, G. C. Barber, A. Fadnek, S. L. Milora, P. M. Ryan, D. A. Rasmussen, D. O. Sparks, D. E. Schechter, W. L. Stirling
Fusion Science and Technology | Volume 39 | Number 2 | March 2001 | Pages 1130-1134
Plasma Engineering, Heating, and Current Drive | doi.org/10.13182/FST01-A11963397
Articles are hosted by Taylor and Francis Online.
Record beta and density values have been obtained at the Small Tight Aspect Ratio Tokamak in the United Kingdom Atomic Energy Agency (UKAEA) Fusion Culham Science Centre by using Oak Ridge National Laboratory's (ORNL's) neutral beam injector for plasma heating. This result has improved the prospects for a future spherical tokamak (ST) fusion core device. To address the physics issues of ST plasmas and the technology of neutral beam heating, ORNL neutral beam injectors have been installed on the Mega Amp Spherical Tokamak (MAST) at UKAEA Culham. The goal of the injectors is to provide a neutral beam heating power of 5 MW for 0.5 s, or up to 4 MW for 5 s. To achieve 5-s operation at the required power level of 4 MW, the existing oxide-filament cathode must be replaced with a cathode having long-pulse capability.
In 1983 ORNL developed an advanced positive ion source having long-pulse capability for 50-A and 80-keV hydrogen ion beams. The indirectly heated cathode technology developed for the advanced positive ion source will be utilized to fulfill requirements of long-pulse neutral beam heating on MAST plasmas. The cathode utilizes an electron emitter made of lanthanum oxide (La2O3) doped molybdenum. The cathode is heated by a graphite heater and insulated by a heat shield. The heat shield is made of multiple layers of tantalum sheet. Details of design and performance of such long-pulse cathodes are reported and discussed.
