Investigation of PCI phenomenon in PWR fuel with Transuranus code

The fuel matrix and the cladding constitute the first barrier against radioactive fission product release. Therefore a defense in depth concept requires also the comprehensive understanding of fuel rod behavior and accurate prediction of the lifetime in normal operation and in accident condition as well. Investigations of fuel behavior are carried out in close connection with experimental research operation feedback and computational analyses. In this connection, OECD NEA sets up the “public domain database on nuclear fuel performance experiments for the purpose of code development and validation – International Fuel Performance Experiments (IFPE) database”, with the aim of providing a comprehensive and well-qualified database on UO2 fuel with Zircaloy cladding for model development and code validation. This paper describes the application of the TRANSURANUS code against power ramp tests executed in the research reactor R2 at Studsvik, Sweden. The datasets are part of the International Fuel Performance Experiments (IFPE) database. The experiments address the behavior of PWR fuel rods, including preceding base irradiation, during the over-power ramping. The burnup values range between 28 and 45 MWd/kgU. Pre-, during-, and post- irradiation, non destructive and destructive examinations were executed, in order to determine and understand the behavior of the fuel rods, but also to provide suitable data, useful for code validation. The experimental data were used for assessing the TRANSURANUS capabilities in predicting the phenomenon of the pellet clad interaction (PCI). The objective of the activity has been fulfilled developing input decks suitable for the assessment of TRANSURANUS code version “v1m1j08”. The current paper reports the main outcome of the assessment of the calculations.