DARWIN: An Evolution Code System for a Large Range of Applications

The aim of this article is to present the main capabilities of an evolution code system, DARWIN, developed at CEA (France). It is devoted to radioactivity studies in various application fields such as nuclear fuel cycle, dismantling, thermonuclear fusion, accelerator driven system, medecine etc. All types of nuclides are dealt with: actinides, fission products, activation products, spallation products. Physical quantities calculated by the code are isotope concentration, isotope mass, activity, radiotoxicity, gamma spectra, beta spectra, alpha spectra, neutron production by spontaneous fission and (α,n) reaction, residual heating, for any cooling times until geological times. Both analytical and numerical schemes are developed in the PEPIN2 depletion module of DARWIN to solve the generalized coupled differential depletion equations. The depletion module PEPIN2 is automatically linked to international evaluations (JEF2, ENDF/B6, EAF97…) both for decay data and cross-sections, and to some transport codes su...