Neutron Age Determination in Fast Reactor Materials using the Group Method Marina F. Kabanova, Aleksey V. Yuzhakov, Arian V. Kuzmin, Yuriy V. Kobenko and Elena S. Riabova MATEC Web Conf., 72 (2016) 01040 Published online: 09 August 2016 DOI: 10.1051/matecconf/20167201040