Improved performances of the fast reactor calculational system ERANOS-ERALIB1 due to improved a priori nuclear data and consideration of additional specific integral data
Résumé
A single consistent scheme of calculational methods and nuclear data called ERANOSERALIB1
was produced in 1996 to calculate fast reactor neutronic parameters.It represents a
significant improvement on previous schemes such as CARNAVAL-IV, PROPANE and
VASCO, each of which were required in order to calculate one specific application.The
nuclear data library ERALIB1 has been obtained by a consistent statistical adjustment based
on 355 integral data from 71 different systems.The performance of ERALIB1 is excellent, as
demonstrated during its validation for which all the k eff SUPER-PHENIX data were reproduced
to within 70 pcm.
The only restriction on this satisfactory performance is related to the rather poor prediction
of the sodium void reactivity effect.This was due to very bad nuclear data for 23Na, and the
unsatisfactory methods used to calculate the sensitivity coefficients for the sodium void reactivity
variation deltap Na.To improve the performance relative to this point and to enlarge the domain of
validation several actions have been undertaken: