Abstract

Requirements for improving the reliability, safety, and efficiency of nuclear power plants, as well as increasing the service life of the main NPP equipment up to 60 years, leads to the need to introduce new and improve existing technologies for maintaining water-chemical regimes. One of the directions of such improvement is the decommissioning of equipment and pipelines made of copper-containing alloys. For the operating NPPs with VVER-1000, AO Rosenergoatom Concern developed and implemented a program to replace the turbine condenser’s tube system with one made of stainless steels or titanium alloys. Such replacement of the equipment of the secondary circuit made of copper-containing alloys was aimed at ensuring the safe and reliable operation of the steam generator (SG) and extending its residual life. The implementation of the program has significantly increased the reliability of the turbines and equipment of the condensate-feed tract and provided the suction of cooling water at the level of worldwide values. The condenser’s tube system of NPP turbines for cooling water with low- or medium salinity is made of stainless steel, while it is made of titanium alloy for cooling water with high salinity. This article analyzes the water chemistry regime at NPPs with a VVER-1000 before and after the reconstruction of the turbine condenser’s tube system. The calculations and analysis of the water chemistry management presented in the article were carried out according to the measured concentrations of impurities in the “salt” sections of the SG, since the content of impurities in the feed water and condensate, as a rule, was less than 1 μg and is at the lower limit of sensitivity of the methods and devices used.

中文翻译：

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汽轮机冷凝器管系统改造前后使用VVER-1000的NPP处的水化学状态分析

摘要

要求提高核电厂的可靠性，安全性和效率，以及将主要核电厂设备的使用寿命延长至60年，导致需要引入新的和改进的现有技术来维持水化学体系。这种改进的方向之一是使含铜合金制成的设备和管道退役。对于运行VVER-1000的NPP，AO Rosenergoatom Concern开发并实施了一项程序，以用不锈钢或钛合金制成的涡轮机冷凝器的管道系统代替该系统。此类由含铜合金制成的二次回路设备的更换旨在确保蒸汽发生器（SG）的安全可靠运行并延长其剩余寿命。该计划的实施极大地提高了凝结水供应系统的涡轮机和设备的可靠性，并使冷却水的抽吸达到了世界范围的水平。NPP涡轮机的冷凝器管道系统用于冷却低盐度或中等盐度的水，由不锈钢制成，而由钛合金制成，用于冷却高盐度的水。本文分析了涡轮冷凝器管道系统改造前后使用VVER-1000的NPPs的水化学状态。本文中介绍的水化学管理的计算和分析是根据SG的“盐”部分中测得的杂质浓度进行的，因为通常进料水和冷凝水中的杂质含量为：