EASY-II archive

The European Activation SYstem (EASY), developed and maintained at Culham Centre for Fusion Energy, is an international standard for simulation of activation, transmutation processes caused by nuclear reactions and decay. It integrates information from data files and collaborators around the world into a single user-friendly package, which is invaluable for nuclear researchers and has wider applications for industry; nuclear fission and fusion, accelerator physics, isotope production, stockpile and fuel cycle stewardship, materials characterisation, life and storage cycle management.

The European Activation SYstem EASY-II has been re-engineered and re-written in modern f95 programming language so as to answer today’s and tomorrow’s needs in terms of activation, transmutation, depletion, burnup and inventory requirements. The FISPACT-II code development project has allowed to embed many more features in terms of energy range; up to GeV; incident particles, alpha, gamma, proton, deuteron, neutron; and neutron physics, self-shielding effects, temperature dependence and covariance so as to really cover all application needs: transport, shielding, inventory, medical, astrophysics.

In parallel, the maturity of modern, truly general purpose libraries encompassing thousands of target isotopes such as TENDL, the evolution of the ENDF nuclear data format and the capabilities of the latest generation of processing codes PREPRO, NJOY and CALENDF have allowed the inventory code to be fed with more robust, complete and appropriate data forms: cross sections with covariance, probability tables in the resonance ranges, kerma, dpa, gas and radionuclides production and up to 23 decay types. All such data for the five most important incident particles (n, p, d, alpha, gamma) are available in evaluated data files with information up to an incident energy of 200 MeV.

The resulting code system, EASY-II is designed as a functional replacement for the previous European Activation SYstem, EASY-2010. It includes many new features and enhancements, but also benefits already from the feedback from extensive validation and verification activities performed with its predecessor.

EASY has a long history. A code called FISPACT was initially written by UKAEA at AERE Harwell in 1987 based on the already existing code FISPIN that used the algorithm (EXTRA) developed at AEE Winfrith in 1976 to solve systems of differential equations for fission product nuclide inventory calculations. Although it used the same algorithm and structure as FISPIN, it was extended to treat fusion technology issues and eventually included many unique new features such as uncertainties in radiological quantities, gas production and pathway analysis. It became the recommended inventory code for European fusion calculations when using the European Activation File (co-developed by UKAEA Culham and NRG Petten from original work by Westinghouse Hanford) as the source of nuclear data, and this later evolved into the EASY activation analysis system.                                                      

EASY-II(13) versus EASY-2010      EASY-II poster

Decay heat validation, FISPACT-II & TENDL-2013, JEFF-3.2, ENDF/B-VII.1 and JENDL-4.0 nuclear data libraries

Decay heat validation, FISPACT-II & TENDL-2012,-2011 and EAF-2010 nuclear data libraries

TENDL-2012 processing, verification and validation steps

TENDL-2011 processing and criticality benchmarking