Nuclear power plant support activities in reactors chemistry at CNEA

Argentina has two operating PHWR nuclear power plants. Atucha I NPP is a pressure vessel type heavy water reactor of 360 Mwe with 25 years of operation and Embalse NPP is a pressure tube type CANDU-600 reactor of 640 Mwe. Atucha II, a third plant of 600 Mwe of the pressure vessel type, similar to Atucha I, is being constructed. NASA (Nucleoelectrica Argentina S.A.) currently operates both nuclear power plants. The National Atomic Energy Commission (Comision Nacional de Energia Atomica - CNEA) provides operational support to the plants, including research and development assistance, and actual technical services and maintenance work in different areas. The Chemistry Department, formerly the Reactor Chemistry Department, has carried out projects and support activities to the plants during the past 20 years. The aim of this work is to describe the present organisation, and the activities in Reactor Chemistry, of the Chemistry Department. In particular, the Projects to change the chemical control of the secondary circuit of Atucha I NPP and the Materials Surveillance Program in Embalse NPP primary circuit autoclaves are described. 1. Introduction Argentina has two operating PHWR nuclear power plants. Atucha I NPP is a pressure vessel type heavy water reactor of 360 Mwe with 25 years of operation and Embalse NPP is a pressure tube type CANDU-600 reactor of 640 Mwe. Atucha II, a third plant of 600 Mwe, pressure vessel type similar to Atucha I, is being constructed. NASA (Nucleoelectrica Argentina S.A.) currently operates both nuclear power plants. The National Atomic Energy Commission (Comision Nacional de Energia Atomica - CNEA) provides operational support to the plants, including research and development assistance and actual technical services and maintenance work in different areas. The Chemistry Department (ChD), formerly the Reactor Chemistry Department, has carried out projects and support activities to the plants during the past 20 years. 2. Organisation of the Chemistry Department Reactor Chemistry (RCh) is one of the main activities of the Chemistry Department (Head, M.A. Blesa). RCh activities focuses on chemical problems of nuclear plants that are carried out by several Groups of ChD. Co-ordination of the RCh activities is the task of the specific Reactor Chemistry Co-ordination (M. Chocron, Co-ordinator). RCh activities include RD to a larger or lesser degree, they are all involved in RCh activities.