BWR (boiling-water reactor) radiation control: In-plant demonstration at Vermont Yankee: Final report
Results of the RP1934 program, which was established by EPRI in 1981 to demonstrate the adequacy of BRAC program (RP819) principles for BWR radiation control at Vermont Yankee, are presented. Evaluations were performed of the effectiveness of optimization of purification system performance, control of feedwater dissolved oxygen concentrations, minimization of corrosion product and ionic transport, and improved startup, shutdown, and layup practices. The impact on shutdown radiation levels of these corrective actions was assessed based on extensive primary system radiation survey and component gamma scan data. Implementation of the BRAC recommendations was found to be insufficient to reduce the rate of activity buildup on out-of-core surfaces at Vermont Yankee, and additional corrective actions were found necessary. Specifically, replacement of cobalt-bearing materials in the control rod drive pins and rollers and feedwater regulating valves was pursued as was installation of electropolished 316 stainless steel during a recirculation piping replacement program. Aggressive programs to further reduce copper concentrations in the reactor water by improving condensate demineralizer efficiency and to minimize organic ingress to the power cycle by reducing organic concentrations in recycled radwaste also were undertaken. Evaluations of the impact on activity buildup of several pretreatment processes including prefilming in moist air, preexposure to high temperature water containing zinc, and electropolishing also were performed in a test loop installed in the reactor water cleanup system. A significant beneficial impact of electropolishing was shown to be present for periods up to 6000 hours.
- Research Organization:
- NWT Corp., San Jose, CA (USA)
- OSTI ID:
- 6046242
- Report Number(s):
- EPRI-NP-5455; ON: DE88920083; TRN: 87-040400
- Country of Publication:
- United States
- Language:
- English
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VERMONT YANKEE REACTOR
RADIATION MONITORING
RADIATION PROTECTION
RADIATION TRANSPORT
CONTROL ROD DRIVES
CORROSION
ELECTROPOLISHING
EXPERIMENTAL DATA
FEEDWATER
PIPES
REACTOR COMPONENTS
REACTOR COOLING SYSTEMS
REACTOR MATERIALS
REACTOR OPERATION
STAINLESS STEEL-316
VALVES
WATER CHEMISTRY
ALLOYS
BWR TYPE REACTORS
CHEMICAL REACTIONS
CHEMISTRY
CHROMIUM ALLOYS
CHROMIUM STEELS
CHROMIUM-NICKEL STEELS
CONTROL EQUIPMENT
COOLING SYSTEMS
CORROSION RESISTANT ALLOYS
DATA
ELECTROLYSIS
ENERGY SYSTEMS
ENRICHED URANIUM REACTORS
EQUIPMENT
FLOW REGULATORS
HEAT RESISTANT MATERIALS
HEAT RESISTING ALLOYS
HYDROGEN COMPOUNDS
INFORMATION
IRON ALLOYS
IRON BASE ALLOYS
LYSIS
MATERIALS
MOLYBDENUM ALLOYS
MONITORING
NICKEL ALLOYS
NUMERICAL DATA
OPERATION
OXYGEN COMPOUNDS
POLISHING
POWER REACTORS
REACTORS
STAINLESS STEELS
STEELS
SURFACE FINISHING
THERMAL REACTORS
WATER
WATER COOLED REACTORS
WATER MODERATED REACTORS
220500* - Nuclear Reactor Technology- Environmental Aspects
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