Water quality management program for IPR-R1 TRIGA® research reactor

Abstract

The IPR-R1 Triga nuclear research reactor of the Nuclear Technology Development Center (CDTN) is one of the oldest reactors in operation in the world. It is a compact and inherently safe reactor that operates at a continuous power level of 100 kW with a solid homogeneous General Atomic (GA) fuel element of zirconium hydride moderator homogeneously combined with 20% enriched uranium. The reactor core is at the bottom of a tank under approximately 6.0 meters of shielding water. The long operation time of the reactor, 63 years, and the contact of the water with the core, can induce corrosive processes in the IPR-R1 reactor and affect its safe operation. To keep the water quality according to the chemical-physical recommended standards, a quality management program, as recommended by the International Atomic Energy Agency (IAEA), was implemented. The water quality management program is a guideline of good practices applied to nuclear reactors, targeting to keep their water coolants at specified physical-chemical standard. The main aim of the present work is to introduce IPR-R1 Triga’s water chemistry program results from the second half of 2022 till the first half of 2023, when the installation returned to its regular activities after the Covid-19 pandemic. The physical-chemical parameters evaluated (e.g.: pH, alpha and beta radiation, electrical conductivity and gamma emitters) shows that the IPR-R1 reactor operates within recommended safety standards.