Weibull statistical models of K-Ic/K-Ia fracture toughness databases for pressure vessel steels with an application to pressurized thermal shock assessments of nuclear reactor pressure vessels

This paper presents new statistical representations of recently extended fr acture toughness K-Ic, and K-Ia, databases for pressure vessel steels. Thes e models were developed by the Heavy Section Steel Technology program at Oa k Ridge National Laboratory in support of the current effort by the U.S. Nu clear Regulatory Commission to update its regulatory guidance for pressuriz ed-thermal-shock (PTS) transients in nuclear reactor pressure vessels. The Weibull distribution, with two of its parameters calculated by the Method o f Moments point-estimation technique, forms the basis for the new statistic al models. An application of the new K-Ic/K-Ia models, as implemented in th e FAVOR probabilistic fracture mechanics computer program, is also presente d for three PTS transients. (C) 2001 Elsevier Science Ltd. All rights reser ved.