Reduced-activation ferritic-martensitic

Purthermore, as mentioned in Section 9.1, FM steels have also been chosen as structural materials for high dose components of other nuclear systems such as fusion reactors. The fusion community has developed new FM steels, called reduced-activation ferritic-martensitic (RAFM) steels, derived from conventional FM steels, with the objective to achieve enhanced radioactive decay resulting in reduced activation following the end-of-life of the components. To this end, radiologicaUy undesirable elements, such as Mo and Nb, were replaced by W and Ta [24]. The physical metallurgy and mechanical... 

S.J. Zinkle, J.L. Boutard, D.T. Hoelzer, A. Kimura, R. Lindau, G.R. Odette, M. Rieth, L. Tan, H. Tanigawa, Development of next generation tempered and ODS reduced activation ferritic/martensitic steels for fusion energy appheations, Nucl. Fusion (2016) (in press). 

L. Tan, L.L. Snead, Y. Katoh, Development of new generation reduced activation ferritic-martensitic steels for advanced fusion reactors, J. Nucl. Mater. (2016) (submitted). 

T. Nozawa, S. Noh, and H. Tanigawa, "Determining the Shear Fracture Properties of HIP Joints of Reduced-Activation Ferritic/Martensitic Steel by a Torsion Test," J. Nucl. Mater., 427[l-3] 282-89 (2012). 

Prevention and mitigation of the mechanical degradation process involving carbon can be done keeping the carbon activity in liquid sodium low (carbon concentration should be below 20 wppm) and selecting reference materials with low carbon activity with respect to liquid Na such as to prevent material decarburization. For instance, as reported in Ref. [75] the austenitic steel AISI 316 and the ferritic/martensitic steels 9Cr have a low carbon activity and the carbon activity in 2.25Cr-lMo steel can be reduced by adding Nb [20]. 

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