Heavy-Section Steel Technology Program. Quarterly progress report, July--September 1977
The Heavy-Section Steel Technology (HSST) Program is an engineering research activity conducted by the Oak Ridge National Laboratory 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 seven tasks: program administration and procurement, fracture mechanics analyses and investigations, effect of high-temperature primary reactor water on subcritical crack growth, investigations of irradiated materials, pressure vessel investigations, thermal shock investigations, and foreign research. Stress intensity factors measured on photoelastic models of BWR vessels and intermediate test vessels (ITVs) with nozzles are consistent with values deduced from burst tests of the ITVs. The ITV models reproduced effects locally present in the BWR nozzles with a safety margin of 20 to 50%. Subcritical crack growth specimens are being subjected to low-frequency cyclic loading and ramp and hold cycles in a PWR environment. Starting DELTA K appears to affect crack growth rate in the high-temperature water environment. A series of unirradiated (control) Charpy V-notch impact specimens from weldments in the second 4T-CTS irradiation were tested. Assembly of three capsules for the next irradiation was completed. Intermediate test vessel V-7B was pressurized to the point of failure in a hydraulic sustained-load replication of two earlier tests but with the flaw in the vicinity of the heat-affected zone of a half-bead weld repair. Evaluations and preparations for crack-arrest and further ITV tests were made. Cryogenic quenching as a means of performing a warm prestressing thermal shock test and crack arrest tests is being studied.
- Research Organization:
- Oak Ridge National Lab., Tenn. (USA)
- DOE Contract Number:
- W-7405-ENG-26
- OSTI ID:
- 5005848
- Report Number(s):
- ORNL/NUREG/TM-166
- Country of Publication:
- United States
- Language:
- English
Similar Records
Heavy-Section Steel Technology Program. Quarterly progress report, April--June 1977
Heavy-Section Steel Technology Program. Quarterly progress report, October--December 1977
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220200 -- Nuclear Reactor Technology-- Components & Accessories
36 MATERIALS SCIENCE
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42 ENGINEERING
420500 -- Engineering-- Materials Testing
ALLOYS
CONTAINERS
CONTROL
IRON ALLOYS
IRON BASE ALLOYS
MATERIALS TESTING
MECHANICAL PROPERTIES
PRESSURE VESSELS
QUALITY CONTROL
REACTOR MATERIALS
STEELS
TESTING