Americium-241 integral radiative capture cross section in over-moderated neutron spectrum from pile oscillator measurements in the Minerve reactor

¹ CEA, DEN, DER/SPEx, Cadarache, 13108 Saint-Paul-lez-Durance, France
² CEA, DEN, DER/SPRC, Cadarache, 13108 Saint-Paul-lez-Durance, France
³ CENBG, CNRS/IN2P3, Université de Bordeaux, Chemin du Solarium, BP. 120, 33175 Gradignan, France
⁴ CIEMAT – Nuclear Fission Division – Avenida Complutense, 40, 28040 Madrid, Spain
⁵ EC-JRC, 2440 Geel, Belgium

^a e-mail: benoit.geslot@cea.fr

Published online: 13 September 2017

Abstract

An experimental program, called AMSTRAMGRAM, was recently conducted in the Minerve low power reactor operated by CEA Cadarache within the frame of the CHANDA initiative (Solving CHAllenges in Nuclear Data). Its aim was to measure the integral capture cross section of ²⁴¹Am in the thermal domain. Motivation of this work is driven by large differences in this actinide thermal point reported by major nuclear data libraries. The AMSTRAMGRAM experiment, that made use of well characterized EC-JRC americium samples, was based on the oscillation technique commonly implemented in the Minerve reactor. First results are presented and discussed in this article. A preliminary calculation scheme was used to compare measured and calculated results. It is shown that this work confirms a bias previously observed with JEFF-3.1.1 (C/E-1 = −10.5 ± 2%). On the opposite, the experiment is in close agreement with ²⁴¹Am thermal point reported in JEFF-3.2 (C/E-1 = 0.5 ± 2%).