There are 2 repositories under nuclear-data topic.
OpenMC Monte Carlo Code
A curated list of open source projects used in nuclear science and engineering
Sampling nuclear data and uncertainty
Format description for ACE nuclear data files
Nuclear radiation sensor with ionization chamber as a detector. Hard to make, IMHO inferior to semiconductor detectors.
Read and combine data from the Atomic mass evaluation (AME) and NUBASE data files into a single array (std::vector) which can then be manipulated as required, or written to files for use with other code and software.
An open source utility to convert various publicly available macroscopic nuclear cross section formats
A small python library to read multigroup nuclear data libraries.
Ternary Fission Simulations
Neutron spectrum regrouping and adjustment tools.
Nuclear data processing with ACEMAKER, FRENDY and NJOY
Simple codebase to analyze and download Evaluated Nuclear Data Files (ENDFs).