b'depth of Zircaloy2 tubing was morechloric, and nitric acid at 30-90CFigure 4. GE rodlets removed than 600 m while for C26M the wearshowed that the dissolution rates of thefrom ATR after ~ 20 GWd/MTU was ~200 m deep and for APMT wasIronClad tubing was several orders ofirradiation~130 m deep.Thermal aging studiesmagnitude faster than the dissolution of APMT tubing showed that even afterrate of the current Zircaloy-2 tubes, aging for 1000h at 450C (when alphawhich will facilitate the reprocessing prime formation was identified), thedevelopment of IronClad. GNFs manu-tube had a 315C elongation ductilityfacturing plant is moving forward to of ~10% compared to a ~15%ready the facility for LEU+ operations ductility for the non-aged tube. PIEbased on Criticality Safety Analysis studies of the rodlets removed from(CSA) and Integrated Safety Analysis the ATR will demonstrate if neutron(ISA) work. GNF has been working irradiation contributes to any loss ofon a risk informed licensing approach ductility of APMT. Immersion tests forfor High Burnup (HBU) application, one year at 288C showed that thewhich has been already discussed with presence of 5 ppb of dissolved Zn2+the Nuclear Regulatory Commission. considerably decreased the dissolutionGNF is also working with the Nuclear rate of IronClad tube coupons, espe- Energy Institute regarding federal cially for the lower Cr C26M. Immer- funding and the implementation of sion and electrochemical corrosionATF concepts in the current light water tests conducted in sulfuric, hydro- reactor fleet.2021|AFC ACCOMPLISHMENTS 93'