FISPACT

FISPACT
Name	FISPACT
Latest release	2024
Programming language	Fortran, Python
Developer	CCFE, UKAEA
Operating system	Unix, Linux, Windows
License	Open-source / commercial

FISPACT

FISPACT is a nuclear inventory and activation code used for predicting nuclide inventories, decay heat, radiation fields, and transmutation in materials exposed to neutron, proton, deuteron, alpha, gamma and electron irradiations. It is used by researchers and engineers to support projects at institutions such as Culham Centre for Fusion Energy, United Kingdom Atomic Energy Authority, European Commission, ITER, and CERN and to interact with nuclear data libraries produced by organizations like International Atomic Energy Agency, OECD Nuclear Energy Agency, and Los Alamos National Laboratory.

Overview

FISPACT performs inventory calculations by combining reaction cross sections, decay data, and irradiation histories to produce time-dependent inventories, activity, dose rates, and kerma. It interfaces with nuclear data from libraries such as the Evaluated Nuclear Data File, ENDF/B-VIII.0, TENDL, JEFF, and JENDL and supports transport code coupling with MCNP, Serpent, SCALE, OpenMC, and PHITS. The code is used in contexts ranging from fusion research at ITER and JET to fission reactor materials studies at EDF Energy and safety analysis for facilities like Sellafield.

History and Development

Development traces to work at United Kingdom Atomic Energy Authority and the Culham Centre for Fusion Energy with origins in activation modelling needs for magnetic confinement devices such as JET and stellarator projects like W7-X. Early versions were influenced by inventory codes developed at Los Alamos National Laboratory and in collaboration with the Nuclear Energy Agency. Funding and collaboration have involved agencies including the European Commission Framework Programmes, the Engineering and Physical Sciences Research Council, and bilateral programs with national laboratories such as Oak Ridge National Laboratory, Argonne National Laboratory, Lawrence Livermore National Laboratory, and Sandia National Laboratories. Over successive releases the codebase incorporated modern software practices alongside data integration with projects like Nuclear Data Standards and community efforts at NEA Data Bank.

Features and Capabilities

FISPACT offers time-dependent inventory, activation, transmutation, and decay heat calculations with support for multi-particle incident fields and complex irradiation schedules. Capabilities include predictive dose-rate mapping for maintenance planning at facilities like CERN and ITER, lifetime radiation damage assessment for materials studied at Oak Ridge National Laboratory and Lawrence Berkeley National Laboratory, isotope production estimation for radioisotope facilities such as NTP and isotope supply chains, and safety case inputs for repositories like Hanford Site and La Hague. It supports sensitivity and uncertainty analysis using covariance data from sources such as ENDF and TENDL, and integrates with visualization and workflow tools used at European XFEL, Diamond Light Source, and national labs.

Methodology and Models

FISPACT solves coupled linear differential equations representing production and loss of nuclides using stiff ordinary differential equation solvers and matrix exponential techniques common to inventory codes. It applies reaction modeling informed by evaluated libraries from ENDF/B-VIII.0, JEFF-3.3, TENDL-2021, and JENDL-5 with branching ratios and decay schemes from databases maintained by IAEA and ORNL. Damage metrics such as displacements per atom (DPA) and gas production are calculated using standards and models referenced in publications from ASTM International, IAEA technical reports, and research outputs from Culham Centre for Fusion Energy and Universidad Politécnica de Madrid groups.

Data Inputs and Libraries

Primary inputs include cross-section libraries, decay and fission yield data, and irradiation scenarios. Supported evaluated data formats include ENDF and ACE; libraries commonly used with FISPACT include ENDF/B-VIII.0, JEFF-3.3, TENDL-2021, JENDL-5, and specialty libraries from ORNL and IAEA. Fission yield data from sources such as WPEC and decay data curated by Brookhaven National Laboratory and IAEA are employed. Additional activation-relevant datasets include gas-production, kerma, and secondary-particle production matrices aligned with outputs from transport codes like MCNP6, Serpent 2, OpenMC, and FLUKA.

Applications and Use Cases

FISPACT is applied in fusion materials planning for devices such as ITER, JET, WEST, and W7-X; in fission reactor component lifetime studies at utilities like EDF Energy and national labs such as Argonne National Laboratory; in accelerator-driven system design at CERN and RAL; in medical isotope production assessments linked to facilities like National Institute of Radiological Sciences and Brookhaven National Laboratory; and in decommissioning and waste management planning for sites including Sellafield, La Hague, and Hanford Site. It is used in regulatory assessments submitted to bodies such as the Office for Nuclear Regulation and in international projects coordinated by ITER Organization and the European Commission.

Validation and Benchmarking

Validation relies on benchmark comparisons with integral experiments, irradiation rigs, and post-irradiation examination data from facilities including JET, PROTEUS, JEFF benchmark suite, EIR, HFR Petten, SINQ, and experiments at Oak Ridge National Laboratory. Users compare FISPACT predictions against measured activities, gamma spectra, and decay heat from samples irradiated in reactors such as BR2 and research reactors managed by Czech Technical University and Instituto de Pesquisas Energéticas e Nucleares. International benchmark efforts coordinated by OECD/NEA and technical meetings at IAEA provide community oversight for uncertainty quantification and model improvements.

Licensing and Distribution

FISPACT is distributed under a mix of open-source and commercial licensing models, with source and binaries provided to research institutes, industry partners, and national laboratories. Distribution channels include institutional agreements with Culham Centre for Fusion Energy and collaborative arrangements with organizations such as UKAEA, European Commission projects, and national research councils like EPSRC and ANSTO. Training, support, and bespoke validation services are offered via contracts involving laboratories such as Oak Ridge National Laboratory, Lawrence Livermore National Laboratory, and regional nuclear technology providers.

Category:Nuclear technology