Fast neutron environments.

Abstract

The goal of this LDRD project is to develop a rapid first-order experimental procedure for the testing of advanced cladding materials that may be considered for generation IV nuclear reactors. In order to investigate this, a technique was developed to expose the coupons of potential materials to high displacement damage at elevated temperatures to simulate the neutron environment expected in Generation IV reactors. This was completed through a high temperature high-energy heavy-ion implantation. The mechanical properties of the ion irradiated region were tested by either micropillar compression or nanoindentation to determine the local properties, as a function of the implantation dose and exposure temperature. In order to directly compare the microstructural evolution and property degradation from the accelerated testing and classical neutron testing, 316L, 409, and 420 stainless steels were tested. In addition, two sets of diffusion couples from 316L and HT9 stainless steels with various refractory metals. This study has shown that if the ion irradiation size scale is taken into consideration when developing and analyzing the mechanical property data, significant insight into the structural properties of the potential cladding materials can be gained in about a week. 4 ACKNOWLEDGMENTSThe authors would like to thank Dan Buller and Stuart Van Deusen for their time and expertise needed to complete the high temperature ion implantations. The authors would also like to thank Stuart Maloy, Andrew T. Nelson, and Osman Anderoglu for the many useful discussions and for supplying the HT9 steel used to produce the diffusion couples. The authors would also like to