English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

A simple and analytical formula is suggested to solve the problems of thelocal burnup and the isotope distributions. The present method considers twoextreme conditions of neutrons penetrating the fuel rod. Based on theseconsiderations, the formula is obtained to calculate the reaction rates of$^{235}$U, $^{238}$U, and $^{239}$Pu and straightforward the local burnup andthe isotope distributions. Starting from an initial burnup level, theparameters of the formula are fitted to the reaction rates given by a MonteCarlo (MC) calculation. Then the present formula independently gives verysimilar results as the MC calculation from the starting to high burnup level,but takes just a few minutes. The relative reaction rates are found to bealmost independent on the radius (except $(n,\gamma)$ of $^{238}$U) and theburnup, providing a solid background for the present formula. A more realisticexamination is also performed when the fuel rods locate in an assembly. Acombination of the present formula and the MC calculation is expected to have anice balance on the accuracy and the cost on time.

A simple formula for local burnup based on constant relative reaction rate per nuclei