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Washington, DC|Washington Hilton
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Empowering the next generation: ANS’s newest book focuses on careers in nuclear energy
A new career guide for the nuclear energy industry is now available: The Nuclear Empowered Workforce by Earnestine Johnson. Drawing on more than 30 years of experience across 16 nuclear facilities, Johnson offers a practical, insightful look into some of the many career paths available in commercial nuclear power. To mark the release, Johnson sat down with Nuclear News for a wide-ranging conversation about her career, her motivation for writing the book, and her advice for the next generation of nuclear professionals.
When Johnson began her career at engineering services company Stone & Webster, she entered a field still reeling from the effects of the Three Mile Island incident in 1979, nearly 15 years earlier. Her hiring cohort was the first group of new engineering graduates the company had brought on since TMI, a reflection of the industry-wide pause in nuclear construction. Her first long-term assignment—at the Millstone site in Waterford, Conn., helping resolve design issues stemming from TMI—marked the beginning of a long and varied career that spanned positions across the country.
Marc A. Firestone, Jonathan W. Morrow-Jones, Tak Kuen Mau
Fusion Science and Technology | Volume 32 | Number 3 | November 1997 | Pages 390-403
Technical Paper | Plasma Control Issues for Tokamaks | doi.org/10.13182/FST97-A3
Articles are hosted by Taylor and Francis Online.
Results for the first simulated comprehensive feedback control study for a tokamak operating in the fusion regime are presented. A standard Burning Plasma Experiment (BPX) design is the simulated reactor, but the results apply to any tokamak. Feedback gains are derived for specific classes of dynamic models and control objectives using model-based optimal control. An integrated control approach treats both kinetic and electromagnetic parameters and radial profiles. The control actuators include poloidal field coils, fast-wave and lower-hybrid current drive and heating sources, and pellet fuel injectors. Results show that the strongly coupled plasma parameters provide unintended secondary responses to controller inputs. In particular, attempts to modify the q-profile greatly affect the temperature and density profiles when the transport model incorporates International Thermonuclear Experimental Reactor (ITER) scaling. The hot, highly conductive plasma and poor source penetration in the nominal BPX discharge make the central q-values difficult to regulate. Fusion events also complicate the control efforts. Further, simple plasma circuit models are inadequate to account for a significantly evolving current profile. Proper understanding and use of integrated, model-based feedback control will avoid these pitfalls.