Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Decontamination of Ontario hydro reactors

Conference · · Trans. Am. Nucl. Soc.; (United States)
OSTI ID:5580163

Within Ontario Hydro, decontamination of heat transport systems is carried out using the Candecon process. This process involves the addition of organic acidic reagents to the coolant to form a 1 g/kg D/sub 2/O solution that will dissolve and complex the corrosion product oxide layer and contained radioactivity. The solution is circulated through cation exchange resins in the purification circuit to remove complexed metals, thereby regenerating the reagent. When the cation resins are exhausted, mixed bed resins are subsequently used to remove both the reagent and the remaining corrosion products from solution. Filtration, in the form of submicron cartridge filters installed in the purification circuit, is used to remove fine particulate crud produced during the decontamination. Development of the Candecon process led to successful decontaminations of Pickering NGS Units 1 and 2 in 1984. Decontamination factors of up to 10 resulted in radiation fields of 40 to 140 mR/h at the reactor face. These low fields have been a key factor in enabling the successful replacement of all pressure tubes of Unit 1 and 2 reactors. In 1985, Pickering Unit 3 was successfully decontaminated achieving similar decontamination factors.

OSTI ID:
5580163
Report Number(s):
CONF-870837-
Journal Information:
Trans. Am. Nucl. Soc.; (United States), Journal Name: Trans. Am. Nucl. Soc.; (United States) Vol. 54; ISSN TANSA
Country of Publication:
United States
Language:
English