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
2026 ANS Annual Conference
May 31–June 3, 2026
Denver, CO|Sheraton Denver
Latest Magazine Issues
Mar 2026
Jan 2026
Latest Journal Issues
Nuclear Science and Engineering
April 2026
Nuclear Technology
February 2026
Fusion Science and Technology
Latest News
Going Nuclear: Notes from the officially unofficial book tour
I work in the analytical labs at one of Europe’s oldest and largest nuclear sites: Sellafield, in northwestern England. I spend my days at the fume hood front, pipette in one hand and radiation probe in the other (and dosimeter pinned to my chest, of course). Outside the lab, I have a second job: I moonlight as a writer and public speaker. My new popular science book—Going Nuclear: How the Atom Will Save the World—came out last summer, and it feels like my life has been running at full power ever since.
Michel Mélice
Nuclear Science and Engineering | Volume 37 | Number 3 | September 1969 | Pages 451-477
Technical Paper | doi.org/10.13182/NSE69-A19119
Articles are hosted by Taylor and Francis Online.
This paper presents a new attempt towards the development of a systematic method for solving the fuel cycling management optimization problem in modern PWR cores. When the infinite multiplication factor k is used as a single variable to describe the fuel distribution over the core at any stage of its life, the analysis of any reloading pattern can be performed on the basis of its corresponding k-map in the X-Y plane, or more simply, on the basis of its equivalent “k-profile” in cylindrical geometry. Conversely, it is shown how the reloading pattern can be synthesized from the k-profile, which becomes, therefore, the main tool of the method. The search for the best k-profile rests on the analysis of the necessary relations existing, for any particular reloading mode (batch, multiregion, salt-and-pepper, etc.) between the k-profiles and cycle times, and on the use of a cycle “internal optimality condition” aiming to maximize the reactivity of the reloading k-profile, and consequently, the cycle life time, with a constraint on the power-peak factor. As a result, the general many-variable cycling problem can be contracted into a single control-variable problem which, in turn, can be separated into the following two simpler tasks: a cycle internal optimization problem consisting of finding the reloading mode and the single control variable which minimize the stationary cycle cost and a cycle external optimization problem aiming to minimize the cost penalty associated with any deviation of the cycling sequence from the optimal stationary cycle. Using the particular class of optimal k-profiles complying with the maximum power (minimum peak factor) condition, the method is applied to the analysis of the stationary and transient cycles of the SENA reactor, with the three-region mixed reload mode. The methods for calculating the optimal profile classes corresponding to an arbitrary peak factor are also indicated.