Dimensional Stability of Tantalum Control Rods in LMFBRs

Available data on irradiation-induced swelling in tantalum not exposed to flowing sodium has been used to derive the following empirical equation relating swelling to temperature and fluence: %(ΔV/V) = (Φt)^0.4{1.69 exp[−(0.01T − 11.75)² /α] } where A brief review of the literature indicates that unclad tantalum control rods would not behave well in LMFBRs.