New results on the neutron-induced fission cross-section of 231 Pa for incident neutron energies E n = 0.8–3.5 MeV S. Oberstedt a, * , A. Oberstedt b , F.-J. Hambsch a , V. Fritsch a , G. Lo ¨ vestam a , N. Kornilov a a EC-JRC, Institute for Reference Materials and Measurements (IRMM), B-2440 Geel, Belgium b O ¨ rebro University, Department of Natural Sciences, S-70182 O ¨ rebro, Sweden Received 30 June 2005; accepted 18 July 2005 Available online 15 September 2005 Abstract New results on the neutron-induced fission cross-section of 231 Pa in the incident neutron energy range between E n = 0.8 and 3.5 MeV are presented. The individual cross-section data are obtained within an uncertainty of less than 5% and meets the accuracy required by the IAEA in the summary report of the consultantsÕ meeting on ‘‘Assessment of Nuclear Data Needs for Thorium and other Advanced Cycles’’ from 1999. With the new data the hitherto existing large spread between evaluated data files may be removed. Ó 2005 Elsevier Ltd. All rights reserved. PACS: 25.85.Ec; 25.85.w 1. Introduction Major efforts worldwide are currently being carried out in order to develop new concepts of nuclear power generation. One of these concepts is the so-called accelerator driven system (ADS) for energy production and transmutation of 0306-4549/$ - see front matter Ó 2005 Elsevier Ltd. All rights reserved. doi:10.1016/j.anucene.2005.07.005 * Corresponding author. Tel.: +32 14 571 361; fax: 32 14 571 376. E-mail address: stephan.oberstedt@cec.eu.int (S. Oberstedt). Annals of Nuclear Energy 32 (2005) 1867–1874 www.elsevier.com/locate/anucene annals of NUCLEAR ENERGY