The European Activation System (EASY), developed and maintained at Culham Centre for Fusion Energy, is an international standard for data on activation – transmutation caused by nuclear reactions. It integrates information from collaborators around the world into a single user-friendly package which is invaluable for fusion researchers and has wider applications for industry.

EASY-2007 consists of an extensive range of code, data and documentation all aimed at the calculation of the response of materials irradiated by neutrons, deuterons or protons. This new version includes cross section data for deuteron- and proton-induced reactions as well as the neutron data in previous versions. All cross sections covers the energy range 0-60 MeV. It is designed to investigate fusion devices which will act as intense sources of high energy (14 MeV) neutrons and cause significant activation-transmutation of the surrounding materials. Another fusion related activity is the planned materials testing in IFMIF. This is based on an accelerator and will produce neutrons with energies up to 55 MeV. Activation calculations on IFMIF can be carried out using EASY-2007.

The very general nature of the calculational method and the data libraries used for EASY-2007 mean that it is applicable to all situations (e.g. fission reactors or neutron sources) where materials are exposed to neutrons below 60 MeV. In addition activation of materials by deuterons or protons in accelerators can also be calculated. The components of EASY can be divided into two parts: library/code development tools; and user tools. The former are required to develop the latter, however EASY users only need to be able to use the inventory code FISPACT and be aware of the contents of the EAF library (the data source).

The generation of the European Activation File (EAF) is carried out via the SAFEPAQ-II application, which uses as input many world-wide sources of nuclear data. These evaluated files, calculations and experimental data are used to construct a collection of cross section data for neutron-, deuteron- and proton-induced reactions on an extensive set of target nuclides (both stable and unstable), a set of decay data files and other data libraries required by FISPACT.

EASY-2007 is available for personal computers running Windows (2000, XP, Vista and 7) and for UNIX and OsX workstations. It comprises the EAF-2007 nuclear data libraries, FISPACT-2007 and documentation (seven reports). For Windows users there is an additional tool – the EASY-2007 User Interface that enables FISPACT to be run, output files to be summarised, graphs plotted and the EAF data to be viewed.

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.

The EASY-2010 code system is now available through the NEA and RSICC Nuclear Data Centre:

For more information please contact Jean-Christophe Sublet at CCFE – email

Online EAF-2010 Documentation (PDF Files)

The European Activation File: EAF-2010 neutron-induced cross section library 

The European Activation File: EAF-2010 decay data library

The European Activation File: EAF-2010 hazards libraries 

SAFEPAQ-II: User manual 

EAF-2010 fission and capture validation

Validation reports (PDF files)  

Decay power: A comprehensive experimental validation

Validation of EASY-2007 using integral measurements

Revisions and improvements of neutron capture cross sections for EAF-2009 and validation of TALYS calculations

Validation of EASY-2005 above 20 MeV

Online EASY-2007 documentation (PDF files)

The European Activation System: EASY-2007 overview

FISPACT-2007: User manual

The European Activation File: EAF-2007 neutron-induced cross section library

The European Activation File: EAF-2007 deuteron- and proton-induced cross section libraries

The European Activation File: EAF-2007 decay data library

The European Activation File: EAF-2007 biological, clearance and transport libraries

SAFEPAQ-II: User manual

Activation data (PDF file)

Handbook of activation data calculated using EASY-2007