In-situ noble metal deposition and its durability on the catalytic response of stainless steel surfaces in high temperature water

Book · Tue Oct 01 04:00:00 EDT 1996

OSTI ID:367715

Kim, Y J; Andresen, P L; Angeliu, T M ^[1]

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1. GE Corporate Research and Development Center, Schenectady, NY (United States)

The coolant in boiling water reactor (BWR) recirculation lines is high purity, neutral pH water containing dissolved O{sub 2} and H{sub 2}O{sub 2} (100--300 ppb) and dissolved H{sub 2} (10--20 ppb) which are produced by radiolysis. This level of the oxidant (O{sub 2} + H{sub 2}O{sub 2}) is sufficient to induce intergranular stress corrosion cracking (IGSCC) of sensitized austenitic stainless steel (SS). The catalytic response and durability of noble metal coatings were studied by measuring the corrosion potentials in 288 C water containing oxygen and hydrogen. Catalytic surfaces were created on stainless steel by in-situ exposure to 288 C water containing dissolved noble metals. Auger electron microscopy (AES) data showed a noble metal concentration of about 2--3 at.% on the surface and to a depth of about 400 {angstrom}, although other analytical techniques showed that this profile resulted from a thin coating of pure metal on a topologically complex surface. In-situ noble metal deposition on stainless steel resulted in the electrochemical corrosion potential (ECP) well below {minus}230 mV{sub she} under stoichiometric excess hydrogen. The durability of the catalytic surface was also evaluated by measuring the noble metal concentration and corrosion potential of specimens after exposure in an ultrasonic cleaning bath for 1 week in 60 C water and during extended exposure at high flow rate in 288 C water. It was observed that for some noble metal coatings the ultrasonic and high flow exposure caused some loss of noble metals and thereby shifted the corrosion potential in the positive direction.

• OSTI ID: 367715
• Report Number(s): CONF-960389--
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
36 MATERIALS SCIENCE
ADDITIVES
BWR TYPE REACTORS
CORROSION PROTECTION
CRYSTAL DOPING
DOPED MATERIALS
EXPERIMENTAL DATA
IN-SITU PROCESSING
INCONEL 600
PALLADIUM
PLATINUM
PRIMARY COOLANT CIRCUITS
PROTECTIVE COATINGS
REACTOR COMPONENTS
STAINLESS STEEL-304
WATER CHEMISTRY