Radiation buildup control in BWR recirculation piping

Conference · Thu Jan 01 04:00:00 EST 1987 · Trans. Am. Nucl. Soc.; (United States)

OSTI ID:5719386

Meyer, W; Wood, R M; Rao, T V; Vook, R W

Boiling water nuclear reactors (BWRs) employ stainless steel (Type 304 or 316 NG) pipes in which high-purity water at temperatures in the vicinity of 275/sup 0/C are circulated. Various components of the system, such as valves and bearings, often contain hard facing metal alloys such as Stellite-6. These components, along with the stainless steel tubing and feedwater, serve as sources of /sup 59/Co. The presence of even small amounts of /sup 60/Co on the walls of the cooling water system is the dominant contributor to inplant radiation levels. Typical long-term surface activities due to this isotope on the walls of the cooling pipes range from 2.7 to 24 ..mu..Ci/cm/sup 2/. The resulting radiation field limits the allowable exposure time of maintenance and inspection personnel. The object of the research was twofold: (a) to form a thin film diffusion barrier against the outward diffusion of cobalt from a cobalt-containing surface and (b) to prevent the growth of a /sup 60/Co-containing corrosion film. The latter goal was most important since most of the radioactive cobalt will originate from sources other than the stainless steel piping itself. To meet these objectives, an experimental program was carried out using stainless steel rods to simulate the BWR piping and then exposing the rods to simulated BWR conditions in the General Electric Vallecitos /sup 60/Co test loop. It has been shown that the use of protective thin film coatings will reduce /sup 60/Co pickup. Many coatings were tried, but the three best were palladium, nickel, and gold prepared in various ways.

• Research Organization: Syracuse Univ., NY
• OSTI ID: 5719386
• Report Number(s): CONF-870601-
• Conference Information: Journal Name: Trans. Am. Nucl. Soc.; (United States) Journal Volume: 54
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
210100* -- Power Reactors
Nonbreeding
Light-Water Moderated
Boiling Water Cooled
ACTIVITY LEVELS
ALLOYS
BEARINGS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BWR TYPE REACTORS
CHROMIUM ALLOYS
CHROMIUM STEELS
CHROMIUM-NICKEL STEELS
COATINGS
COBALT 59
COBALT 60
COBALT ISOTOPES
CONTROL EQUIPMENT
COOLING SYSTEMS
CORROSION PRODUCTS
CORROSION PROTECTION
CORROSION RESISTANT ALLOYS
DEPOSITION
ENERGY SYSTEMS
EQUIPMENT
FEEDWATER
FLOW REGULATORS
HEAT RESISTANT MATERIALS
HEAT RESISTING ALLOYS
HYDROGEN COMPOUNDS
INTERMEDIATE MASS NUCLEI
INTERNAL CONVERSION RADIOISOTOPES
IRON ALLOYS
IRON BASE ALLOYS
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
MATERIALS
MINUTES LIVING RADIOISOTOPES
MOLYBDENUM ALLOYS
NICKEL ALLOYS
NUCLEI
ODD-EVEN NUCLEI
ODD-ODD NUCLEI
OXYGEN COMPOUNDS
PRIMARY COOLANT CIRCUITS
RADIATION PROTECTION
RADIOISOTOPES
REACTOR COMPONENTS
REACTOR COOLING SYSTEMS
REACTOR SAFETY
REACTORS
SAFETY
STABLE ISOTOPES
STAINLESS STEEL-304
STAINLESS STEEL-316
STAINLESS STEELS
STEELS
TUBES
VALVES
WATER
WATER COOLED REACTORS
WATER MODERATED REACTORS
YEARS LIVING RADIOISOTOPES