The structural features and operating experience of reactors in Russian atomic ships and icebreakers have been described in many articles and monographs, and particularly in [1][2][3][4]. However, certain aspects of the design and operation are known only to specialists directly involved with them. The present authors have been guided by the desire partially to remedy this omission and also to base approaches to the water chemistry of reactors on projected floating power units and low-power nuclear power stations.The material used in the present article is mainly contained in technical scientific reports and operating documentation. A large volume of information accumulated in laboratory research on water-chemical processes, bench tests and (chiefly) in the course of prolonged operation make it possible to propose a generalized approach to the water chemistry of shipborne reactors.Operation over many years has shown the ammonia-water-chemical regime with gas (nitrogen) pressure compensation, used in the first loop of atomic ice breakers and recommended for projected floating power units and low-power nuclear power stations, to be quite simple and reliable.By utilizing nitrogen in the pressure compensation system, replenishing the first loop with ammonia solution, and using KU-2-8Chs strongly acidic cationite in ammonium form and strongly alkaline AV-17-8Chs anionite in hydroxyl form as the filler of the ion-exchange filter, a high pH value (9-10.5) is sustained with an excess hydrogen concentration. The radiolysis of water is then completely suppressed, there is no oxygen or other oxidizing components, and there is a reduction in the rate of corrosion of the structural materials of the loop, sludging, and sludge separation [5]. The regime is characterized by stability and the ability to self-regulate.The water quality norms given in Table 1 were chosen and refined from the results of investigations of the water-chemical regime obtained from special test benches and operating experience. The work was performed with the aim of increasing the stability of the regime and simplifying the technological methods for organizing it. By increasing the stability of the regime it was possible to reduce the number of water-chemical monitoring indices and to establish the minimum number of necessary requirements for monitoring and sustaining them.An analysis of the factors influencing the water-chemical indices provides evidence that the state of the medium and the stability of the regime during normal operation depend, as a rule, on the water quality of the initial filling and replenishment, the processes determining transport in the high-pressure gas system and the quality of the working gas, and the way in which the corrosion processes occur on the internal surfaces of the loop during operation.Among the factors influencing the quality of the medium we omit from consideration events related to irregular situations, including accident s~tuations. From operational experience these include salination from the second loop, error...
