Abstract: Plate heat exchangers used in the cooling and treatment system (PTR) and equipment cooling water system (RRI) of nuclear power plant reactors and spent fuel pools have a complex structure. During operation, radioactive hotspots are prone to accumulate at blind spots such as guide channels and grooves, making radioactive decontamination difficult. In the industry, they are mainly treated as solid radioactive waste. Plate heat exchangers are high-value specialized equipment, therefore NPP operators face significant pressure in cost control and radioactive waste minimization management due to large amount of waste disposal. In view of the above mentioned problems, Hongyanhe Nuclear Power Plant practices and explores decontamination method of radioactive contaminated plate heat exchanger, and adopts the sectional decontamination method "chemical decontamination+foam decontamination+strippable film decontamination" to carry out the test. After decontamination, the surface contamination level of the heat exchanger is less than 0.4 Bq/cm², and the cumulative decontamination rate of the four stages is about 99.80%. 193 radioactive contaminated plate heat exchangers are all reused.

Key words: plate heat exchanger, radioactive decontamination, decontamination rate