Specimen sampling system in a BWR type nuclear power plant

Purpose: To accurately determine the impurity concentration in primary coolants. Constitution: Gold or platinum coating is applied to the inner surface of pipeways for a condensate specimen sampling system led out between a condensator and a low pressure condensate pump, a feed water specimen sampling system branched from a feed water pipeway at the downstream of a feed water heater and a reactor water specimen sampling system connected to a reactor water clean up line lead out from a reactor pressure vessel. Since these pipeways have inner diameter of about 6 mm and length of about 100 mm, stainless steel pipeways applied with platings to the inner surface are preferably used in view of the strength. Since gold or platinum is very much stable chemically at high temperature or low temperature, it neither adsorbs metal ions in the specimen water nor erode to leach out impurities, whereby errors due to the pipeway can be eliminated. (Sekiya, K.)