NEW INFORMATION ON NEUTRON EMBRITTLEMENT AND EMBRITTLEMENT RELIEF OF REACTOR PRESSURE VESSEL STEELS,
Abstract
Neutron embrittlement of the carbon and low-alloy steels investigated has been defined in terms of increases in the nil ductility transition (NDT) temperature. Increases in the NDT of pressure vessel steels as great as 545F have been observed. The extent of embrittlement has been shown to depend upon the neutron exposure, the type of steel, and the irradiation temperature. Embrittlement relief through annealing heat treatment at temperatures above the pressure vessel operating temperature has been demonstrated. Significant embrittlement relief was observed even with multiple irradiation-annealing cycles, the extent of relief being primarily dependent upon the irradiation temperature and the subsequent annealing temperature. Experimental data are reviewed with consideration for application to operating nuclear pressure vessel conditions. Preliminary results of power reactor surveillance and of the evaluation of one pressure vessel after nuclear service are related to experimental results. The value of extending the evaluation of surveillance speciments and of pressure vessels after removal from nuclear service are reviewed with reference to current uncertainties as to possible nuclear environmental and stress effects. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 06, 1964
- Accession Number
- AD0607494
Entities
People
- J. Russell Hawthorne
- Lendell E. Steele
Organizations
- United States Naval Research Laboratory