Heavy-Section Steel Technology Program. Quarterly progress report, April--June 1977

Technical Report · Wed Nov 23 04:00:00 EST 1977

OSTI ID:5350006

Whitman, G D

The Heavy-Section Steel Technology (HSST) Program is an engineering research activity conducted by the Oak Ridge National Laboatory for the Nuclear Regulatory Commission. It comprises studies related to all areas of the technology of the materials fabricated into thick-section primary-coolant systems of light-water-cooled nuclear power reactors. The principal area of investigation is the behavior and structural integrity of steel pressure vessels containing cracklike flaws. Current work is organized into eight tasks: (1) program administration and procurement, (2) fracture mechanics analyses and investigations, (3) effect of high-temperature primary reactor water on subcritical crack growth, (4) investigations of irradiated materials, (5) pressure vessel investigations, (6) thermal shock investigations, (7) foreign research, and (8) prestressed concrete reactor vessel (PCRV) tendon corrosion studies. Stress-intensity factors at nozzle corner cracks, which are measured using photoelastic models, are strongly influenced by the depth of the crack. Fatigue crack growth in pressure vessel steel is being investigated in water reactor environments to evaluate ramp- and hold-time effects. Preparations for testing irradiated weld metal with low ductile shelf toughness are being made using unloading compliance techniques. Preparations have been completed for the testing of vessel V-7B to validate the strength of a vessel containing a large flaw located in the heat-affected zone of an in-service repair weld. Residual stress levels and material properties are being investigated to determine the feasibility of performing an additional intermediate vessel test to evaluate the integrity of in-service weld repairs in the transition temperature regime. A third crack-arrest model was tested. The feasibility of performing cryogenic experiments with pressure vessel steels in cylindrical geometry to study warm-prestressing effects is being evaluated.

• Research Organization: Oak Ridge National Lab., Tenn. (USA)
• DOE Contract Number: W-7405-ENG-26
• OSTI ID: 5350006
• Report Number(s): ORNL/NUREG/TM-147
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360103* -- Metals & Alloys-- Mechanical Properties
BUILDING MATERIALS
CONCRETES
CONTAINERS
CRACKS
FATIGUE
FRACTURE PROPERTIES
MATERIALS
MECHANICAL PROPERTIES
PRESSURE VESSELS
STRESSES
TESTING
THERMAL SHOCK