Boiling Water Reactor feedwater nozzle/sparger. Interim program report

Technical Report · Fri Jul 01 00:00:00 EDT 1977

OSTI ID:5027347

Fife, A B; Kobsa, I R; Riccardella, P C; Watanabe, H T

Several distinct problems have been experienced with the feedwater nozzle and sparger in BWR's. Sparger arm cracking, sparger flow hole cracking, sparger intergranular stress corrosion, and nozzle blend radius and bore cracking have been observed in various operating BWR's. Cracks in the nozzle are believed to be initiated by high cycle fatigue caused by cold feedwater and hot reactor water mixing and exposing the metal surface to rapid water temperature fluctuations. Once initiated the cracks may continue to grow as a result of reactor pressure and feedwater system temperature and flow fluctuations. An analytical treatment of this hypothesis is presented. A comprehensive test program to verify this hypothesis as well as to provide data for solutions to eliminate cracks are detailed. Solutions being considered are feedwater spargers with interference fit, spargers welded to the nozzle safe-end, cladding removal, and system changes to increase the minimum temperature of cold water through the spargers.

• Research Organization: General Electric Co., San Jose, Calif. (USA). BWR Projects Dept.
• OSTI ID: 5027347
• Report Number(s): NEDO-21480; TRN: 12-009067
• Resource Relation: Other Information: Portions of document are illegible
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
BWR TYPE REACTORS
PRIMARY COOLANT CIRCUITS
NOZZLES
CRACKS
FATIGUE
CONFIGURATION
FEEDWATER
STRESS CORROSION
TESTING
THERMAL STRESSES
CHEMICAL REACTIONS
COOLING SYSTEMS
CORROSION
HYDROGEN COMPOUNDS
MECHANICAL PROPERTIES
OXYGEN COMPOUNDS
REACTOR COMPONENTS
REACTOR COOLING SYSTEMS
REACTORS
STRESSES
WATER
WATER COOLED REACTORS
WATER MODERATED REACTORS
210100* - Power Reactors
Nonbreeding
Light-Water Moderated
Boiling Water Cooled