Manager, Materials Engineering, Westinghouse Nuclear Energy, Westinghouse Electric Corporation, Brussels,
Engineer, Nuclear Energy Systems, Westinghouse Electric Corporation, Pittsburgh, Pa.
Chief, Reactor Service, Operating Branch, Ente Nazionale per 1'Energia Elettrica, ENEL, Rome,
Pages: 13 Published: Jan 1976
During preirradiation testing it became known that the Trino reactor vessel material exhibited a Charpy-V upper-shelf impact energy level of approximately 36 ft∙lb in a direction transverse to the plate rolling direction. Current U.S. practice is to require 75 ft∙lb impact energy for materials in the beltline region of the reactor vessel. It was proposed that fracture toughness properties be obtained on Trino reactor vessel Plate W6306-1 in terms of both fracture mechanics parameters and conventional Charpy-V impact energy. Concurrent with preirradiation testing of Plate W6306-1 an accelerated irradiation program was initiated in a test reactor.
To generate the fracture toughness data, compact tension specimens were tested both statically (KIc) and dynamically (Kid). The encapsulated specimens were irradiated at 550°F (288°C to a fluence of 3 × 1019 neutrons (n)/cm2 (E > 1 MeV).
The fracture toughness data obtained from the preirradiation testing indicated that Plate W6306-1 meets the intent of the ASME Appendix G, KIR curve. Postirradiation fracture toughness data (static and dynamic) from the accelerated radiation program indicated that the fracture toughness for transverse specimens was approximately 100 ksi (in.)½. The upper-shelf impact energy of the Trino vessel Plate W6306-1 decreased a maximum of 7 ft∙lb during the accelerated irradiation.
Based on the fracture toughness properties obtained during the evaluation, it was concluded that Plate W6306-1 exhibited adequate toughness to provide for continued safe operation of the Trino Vercellese Nuclear Power Plant.
radiation, fracture (materials), impact tests, fracture tests, dynamic tests, toughness, static hardness tests, equivalent energy, nuclear reactor materials
Paper ID: STP38061S