  Nuclear astrophysics and californium fission neutron spectrum averaged cross
sections and their uncertainties for ENDF materials have been calculated.
Absolute values were deduced with Maxwellian and Mannhart spectra, while
uncertainties are based on ENDF/B-VII.1, JEFF-3.1.2, JENDL-4.0 and Low-Fidelity
covariances. These quantities are compared with available data, independent
benchmarks, EXFOR library, and analyzed for a wide range of cases.
Recommendations for neutron cross section covariances are given and
implications are discussed.
