Characterization of operational environment for steam turbine-blading alloys

Technical Report · Wed Aug 01 04:00:00 EDT 1984

OSTI ID:6777932

Jonas, O; Pebler, A

Steam and water from 42 units were sampled and analyzed to establish concentrations of chloride, sulfate, sodium, phosphate, ammonia, silica, and oxygen, and pH at steady load. Liquid ion chromatography, sensitive from 1 ppB up, was used for the ionic species. To identify concentrated compounds and their mixtures which exist on turbine surfaces, deposits from 105 turbines were analyzed by x-ray diffraction, semiquantitative emission spectroscopy, and by wet chemical methods. A survey of water treatment and water and steam specifications provided information on system characteristics, typical system chemistries as analyzed by operators, and a list of 28 steam and water specifications which reflect anticipated steam chemistry limits. The transport of chemicals in steam power systems and impurity behavior in turbines are described. The average concentration of chlorides, sulfates, phosphates, and sodium in LP steam was found to be less than 10 ppB. 60% of all units tested met the Westinghouse 5 ppB limit for chloride and sodium. This and previous work identified 160 chemical compounds in steam or deposits: sodium hydroxide, sodium and ammonium chlorides and sulfates, and organic and inorganic acids. Copper oxides, which can aggravate corrosion, are frequently present. The environments can be acidic, basic, oxidizing or reducing. Units with blade failures have higher concentrations of chlorides and sulfates in deposits. Carryover of chlorides and sulfates from boiler drum and PWR recirculating steam generators is higher than expected, resulting in acidification of turbine steam. Carryover of phosphate is very low.

• Research Organization: Westinghouse Electric Corp., Orlando, FL (USA). Steam Turbine Generator Div.
• OSTI ID: 6777932
• Report Number(s): EPRI-CS-2931; ON: TI85920048
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
210200* -- Power Reactors
Nonbreeding
Light-Water Moderated
Nonboiling Water Cooled
CHEMICAL COMPOSITION
CHEMICAL REACTIONS
CHEMISTRY
CORROSION
DEPOSITS
HYDROGEN COMPOUNDS
MACHINERY
MASS TRANSFER
NUCLEAR FACILITIES
NUCLEAR POWER PLANTS
OXYGEN COMPOUNDS
POWER PLANTS
PWR TYPE REACTORS
REACTORS
STEAM
STEAM TURBINES
THERMAL POWER PLANTS
TURBINE BLADES
TURBINES
TURBOMACHINERY
WATER
WATER CHEMISTRY
WATER COOLED REACTORS
WATER MODERATED REACTORS
WATER TREATMENT