ANS is committed to advancing, fostering, and promoting the development and application of nuclear sciences and technologies to benefit society.
Explore the many uses for nuclear science and its impact on energy, the environment, healthcare, food, and more.
Explore membership for yourself or for your organization.
Conference Spotlight
Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
Standards Program
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!
Latest Magazine Issues
Jul 2025
Jan 2025
Latest Journal Issues
Nuclear Science and Engineering
September 2025
Nuclear Technology
August 2025
Fusion Science and Technology
Latest News
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.
Ji-Feng Wang, Tsuneo Amano, Yuichi Ogawa, Nobuyuki Inoue
Fusion Science and Technology | Volume 32 | Number 4 | December 1997 | Pages 590-600
Technical Paper | Special Section: Plasma Control Issues for Tokamaks / Plasma Engineering | doi.org/10.13182/FST97-A19906
Articles are hosted by Taylor and Francis Online.
The dynamics of burning plasma for various transient situations in International Thermonuclear Experimental Reactor (ITER) plasma have been simulated with the 1½-dimensional up-down asymmetry Tokamak Transport Simulation code. Attention is paid primarily to intrinsic plasma transport processes such as confinement improvement and changes of plasma profiles. A large excursion of fusion power is shown to take place with a small improvement of plasma confinement; e.g., an increase of the global energy confinement by a factor of 1.2 yields a fusion power excursion of ∼30% within a few seconds. Given this short timescale of the fusion power transient, any feedback control of fueling deuterium-tritium gas is difficult. The effect of plasma profile on fusion power excursion is studied by changing the particle transport denoted by the peaking parameter Cv. When the fusion power excursion is mild and slow, the feedback control is quite effective in suppressing the fusion power excursion and in shortening the duration time of the power transient. Changes of the pumping efficacy are also studied, and large excursions of fusion power are not observed because of a decrease of the fuel density itself when the pumping efficacy is increased; and helium ash accumulates in the case of a decrease of the pumping efficacy. Finally, magnetohydrodynamic sawtooth activity leads to a fusion power fluctuation of ±20%, although such activity is helpful for helium ash exhaust.