tailieunhanh - Lithium and boron analysis by LA-ICP-MS results from a bowed PWR rod with contact

In this work, the equipment was used to investigate the distribution of lithium (7Li) and boron (11B) in the outer oxide at the bow contact area. Depth profiling in the clad oxide at the opposite side of the rod to the point of contact, which is considered to have experienced normal operating conditions and which has a typical oxide thickness, evidenced levels of ∼10–20 ppm 7Li and a 11B content reaching hundreds of ppm in the outer parts of the oxide, largely in agreement with the expected range of Li and B clad oxide concentrations from previous studies. | Lithium and boron analysis by LA-ICP-MS results from a bowed PWR rod with contact EPJ Nuclear Sci. Technol. 3 2 2017 Nuclear Sciences A. Puranen et al. published by EDP Sciences 2017 amp Technologies DOI epjn 2016042 Available online at http REGULAR ARTICLE Lithium and boron analysis by LA-ICP-MS results from a bowed PWR rod with contact Anders Puranen1 Pia Tejland1 Michael Granfors1 David Schrire2 Bertil Josefsson2 and Bernt Bengtsson3 1 Studsvik Nuclear AB 611 82 Nyköping Sweden 2 Vattenfall Nuclear Fuel AB 169 92 Stockholm Sweden 3 Ringhals AB 430 22 Väröbacka Sweden Received 9 October 2015 Accepted 7 December 2016 Abstract. A previously published investigation of an irradiated fuel rod from the Ringhals 2 PWR which was bowed to contact with an adjacent rod identified a significant but highly localised thinning of the clad wall and increased corrosion. Rod fretting was deemed unlikely due to the adhering oxide covering the surfaces. Local overheating in itself was also deemed insufficient to account for the accelerated corrosion. Instead an enhanced concentration of lithium due to conditions of local boiling was hypothesised to explain the accelerated corrosion. Studsvik has developed a hot cell coupled LA-ICP-MS Laser Ablation Inductively Coupled Plasma Mass Spectrometer equipment that enables a flexible means of isotopic analysis of irradiated fuel and other highly active surfaces. In this work the equipment was used to investigate the distribution of lithium 7Li and boron 11B in the outer oxide at the bow contact area. Depth profiling in the clad oxide at the opposite side of the rod to the point of contact which is considered to have experienced normal operating conditions and which has a typical oxide thickness evidenced levels of 10 20 ppm 7Li and a 11B content reaching hundreds of ppm in the outer parts of the oxide largely in agreement with the expected range of Li and B clad oxide concentrations from previous studies. In the contact .