Chemical cleaning for second loop of
CPR1000 nuclear power plant

GUO Dong-hui, LI Ji-bing, SANG Qian-feng

                                                            (China Guangdong Nuclear Power Engineer Co.Ltd., Shenzhen 518000, China)

Abstract: Aiming at the applicability of the chemical cleaning method to the second loop of the nuclear power plant, the test method was used to study the chemical cleaning of the loop pipeline belongs to the second loop of CPR1000 nuclear power plant. Through static rotary coupon method test, dynamic flushing test, passivation and corrosion prevention test, five cleaning reagent and three passivator were tested with 20# carbon steel, 304 stainless steel pipe and the corresponding standard test piece, and the comprehensive cleaning effect anti-corrosion ability after cleaning was got by above-mentioned test. The test effect of each cleaning reagent was analyzed by the data got from the test, and the better chemical cleaning agent is given relatively by comprehensive contrast to the cleaning and anti-corrosion ability; on the basis of static test, the dynamic test is carried out to simulate the actual flushing effect, and matching performance with the result of static test can also be got. Beyond that, the chemistry residual of the system after cleaning was measured, and the assessment of the chemistry residual was got with it. The results indicate that the chemical cleaning method is suitable for CPR1000 Nuclear power unit, EDTA is a relatively better chemical cleaning agent by comprehensive contrast to the cleaning and anti-corrosion ability.
Key words: nuclear power unit; chemical cleaning; corrosion prevention; chemistry residual