Stress intensity analysis of reactor vessel crack under thermal, irradiation and cyclic loading

The fatigue crack growth rate or propagation behavior of the base and weld materials of a LMFBR or a LWR pressure vessel under the thermal, irradiation (or irradiation and environment), and cyclic loading conditions is analyzed based on experimental results. The power function and exponential function crack (rate) laws and the theory of fatigue crack are introduced and postulated for the stress intensity factor, or the effective stress intensity factor of the fatigue crack propagation behavior in the vessel materials. Experimental data of austenitic stainless steels 304 and 316, nickel alloy Inconel 600, and low-carbon alloy steels A516 and A533 of the LMFBR and LWR pressure vessels were measured, examined, analyzed, evaluated, and plotted for both the power function crack law and the exponential function crack law. The theoretical prediction and computerized experimental data are in excellent agreement and can be applied in the respective LMFBR and LWR pressure vessel design of a nuclear power reactor. (orig./HP)