Experimental Simulation of Neutron Irradiation Damage in Reactor Pressure Vessel Steels

2006 ◽  
pp. 1189-1192
Author(s):  
Fahim Hashmi ◽  
Su Jun Wu ◽  
Huan Xi Li
Keyword(s):  
Neutron Irradiation ◽  
Pressure Vessel ◽  
Reactor Pressure Vessel ◽  
Experimental Simulation ◽  
Irradiation Damage ◽  
Pressure Vessel Steels ◽  
Reactor Pressure

Experimental Simulation of Neutron Irradiation Damage in Reactor Pressure Vessel Steels

2006 ◽  
Vol 324-325 ◽  
pp. 1189-1192
Author(s):  
Fahim Hashmi ◽  
Su Jun Wu ◽  
Huan Xi Li
Keyword(s):  
Neutron Irradiation ◽  
Pressure Vessel ◽  
Structural Integrity ◽  
Reactor Pressure Vessel ◽  
Life Assessment ◽  
Experimental Simulation ◽  
Irradiation Damage ◽  
Irradiation Embrittlement ◽  
Surveillance Programs ◽  
Reactor Pressure

Degradation of reactor pressure vessel (RPV) steels due to neutron irradiation embrittlement is directly related to safety and life of the nuclear power plant (NPP). In order to ensure structural integrity and safe operation of NPP, surveillance programs are conducted to monitor and predict the changes in RPV materials. Availability of irradiated specimen from RPV or irradiation of specimens under simulated conditions of RPV for conducting fracture toughness tests remains a major problem in surveillance programs. In order to resolve this problem, various methods are adopted to experimentally simulate the effect of neutron irradiation on mechanical behavior of RPV steels using electron irradiation, thermal aging, strain hardening, combined quenching and hardening and pre-straining combined with heat treatment. This paper presents a review of the existing research on experimental simulation of neutron irradiation damage through various methodologies and discusses the future scope of their application in plant safety and life assessment of RPV’s.

Effects of Neutron Irradiation on the Mechanical and Electromagnetic Properties of Reactor Pressure Vessel Steels

2017 ◽  
Author(s):  
Li Chengliang ◽  
Shu Guogang ◽  
Chen Jun ◽  
Liu Yi ◽  
Liu Wei ◽  
...  
Keyword(s):  
Neutron Irradiation ◽  
Pressure Vessel ◽  
Power Plants ◽  
Hysteresis Loops ◽  
Reactor Pressure Vessel ◽  
Electromagnetic Properties ◽  
Irradiation Damage ◽  
Indentation Hardness ◽  
Rpv Steel ◽  
Reactor Pressure

The effect of neutron irradiation damage of reactor pressure vessel (RPV) steels is a main failure mode. Accelerated neutron irradiation experiments at 292 °C were conducted on RPV steels, followed by testing of the mechanical, electrical and magnetic properties for both the unirradiated and irradiated steels in a hot laboratory. The results showed that a significant increase in the strength, an obvious decrease in toughness, a corresponding increase in resistivity, and the clockwise turn of the hysteresis loops, resulting in a slight decrease in saturation magnetization when the RPV steel irradiation damage reached 0.0409 dpa; at the same time, the variation rate of the resistivity between the irradiated and unirradiated RPV steels shows good agreement with the variation rates of the mechanical properties parameters, such as nano-indentation hardness, ultimate tensile strength, yield strength at 0.2% offset, upper shelf energy and reference nil ductility transition temperature. Thus, as a complement to destructive mechanical testing, the resistivity variation can be used as a potentially non-destructive evaluation technique for the monitoring of the RPV steel irradiation damage of operational nuclear power plants.

Modeling of Irradiation Embrittlement of Reactor Pressure Vessel Steels

1999 ◽  
Vol 122 (1) ◽  
pp. 60-66 ◽  
Author(s):  
S. Murakami ◽  
A. Miyazaki ◽  
M. Mizuno
Keyword(s):  
Yield Stress ◽  
Neutron Irradiation ◽  
Pressure Vessel ◽  
Void Nucleation ◽  
Reactor Pressure Vessel ◽  
Material Behavior ◽  
Uniaxial Tensile ◽  
Irradiation Embrittlement ◽  
Pressure Vessel Steels ◽  
Reactor Pressure

A model to describe the change in the inelastic and fracture properties of reactor pressure vessel steels due to neutron irradiation in the ductile region (i.e., irradiation embrittlement) is developed. First, constitutive equations for unirradiated elastic-viscoplastic-damaged materials are developed within the framework of the irreversible thermodynamics theory. To take into account the effect of hydrostatic pressure on the nucleation and growth of microvoids, properly defined dissipation potential is used. Then, the effect of irradiation on the material behavior is incorporated into the proposed model as a function of neutron fluence Φ by taking into account the interaction between irradiation-induced defects and movable dislocations. As regards the damage strain threshold pD, the mechanism of void nucleation due to pile-up of dislocations at the inclusions in the material is proposed first under unirradiated-condition, and then the effect of irradiation on the mechanism is formulated. In order to demonstrate the validity of this model, it is applied to the case of uniaxial tensile loading of a low alloy steel A533B cl. 1 for the pressure vessel use of light-water reactors at 260°C. The resulting model can describe the increase in yield stress and ultimate tensile strength, the decrease in total elongation and strain hardening, and the strain rate dependence of yield stress due to neutron irradiation. [S0094-4289(00)00901-4]

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