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Conference Spotlight
2025 ANS Winter Conference & Expo
November 9–12, 2025
Washington, DC|Washington Hilton
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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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Latest News
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.
Hiroshi Mitani
Nuclear Science and Engineering | Volume 51 | Number 2 | June 1973 | Pages 180-188
Technical Paper | doi.org/10.13182/NSE51-180
Articles are hosted by Taylor and Francis Online.
A higher order perturbation formula for calculating changes in the reactivity up to a desired order in concise form is given; the formula uses the iterative technique well known in quantum mechanics and in the neutron life-cycle method. This procedure is possible only when the adjoint flux in the unperturbed system is used as the weighting function. The higher order perturbation formula contains the interaction between the perturbation inserted and its surrounding medium, but it consists only of the integration over the perturbed region. Numerical calculations up to the third-order perturbation show that the first-order perturbation technique gives a low value for the reactivity worths of fission, absorption, and scattering materials; further, the n’th-order perturbation is proportional to the n’th power of the concentration of an inserted perturbation.
