Study of the Evolution of Defects in the Structure of Reactor Pressure Vessel by Rate Theory

2014 ◽  
Vol 10 (1) ◽  
pp. 123-127 ◽  
Author(s):  
Gyeong-Geun Lee ◽  
Yong-Bok Lee ◽  
Min-Chul Kim ◽  
Junhyun Kwon
2001 ◽  
Vol 677 ◽  
Author(s):  
B. D. Wirth ◽  
G. R. Odette ◽  
R. E. Stoller

ABSTRACTThe continued safe operation of nuclear reactors and their potential for lifetime extension depends on ensuring reactor pressure vessel integrity. Reactor pressure vessels and structural materials used in nuclear energy applications are exposed to intense neutron fields that create atomic displacements and ultimately change material properties. The physical processes involved in radiation damage are inherently multiscale, spanning more than 15 orders of magnitude in length and 24 orders of magnitude in time. This paper reports our progress in developing an integrated, multiscale-multiphysics (MSMP) model of radiation damage for the prediction of reactor pressure vessel embrittlement. Key features of the fully integrated MSMP model include: i) combined molecular dynamics (MD) and kinetic lattice Monte Carlo (KMC) simulations of cascade defect production and cascade aging to produce cross-sections for vacancy, self- interstitial and vacancy-solute cluster size classes for times on the order of seconds; ii) an integrated reaction rate theory and thermodynamic code to predict the evolution of nanostructural and nanochemical features for times on the order of decades; iii) a micromechanics model to calculate the resulting mechanical property changes. This paper will focus on the combined use of MD and KMC to simulate the long-term rearrangement (aging) of defects in displacement cascades and thus, produce late-time production cross-sections for vacancy and vacancy cluster features.


Author(s):  
Ken-ichi Ebihara ◽  
Masatake Yamaguchi ◽  
Yutaka Nishiyama ◽  
Kunio Onizawa ◽  
Hiroshi Matsuzawa

The experimental results on neutron-irradiated reactor pressure vessel (RPV) steels have revealed grain boundary segregation of phosphorous (P) due to neutron irradiation, which may lead to intergranular fracture. Because of the lack of experimental database, however, the dependence of the segregation on variables such as dose, dose-rate, and temperature is not clear. Here, we incorporate the parameters determined by first-principles calculations into the rate theory model which was developed for bcc lattice on the basis of the fcc lattice model proposed by Murphy and Perks [1], and apply it to the simulation of irradiation-induced P segregation in bcc iron. We evaluate the grain boundary P coverage and discuss its dependence on dose-rate and irradiation temperature by comparing our results with previously reported results and experimental data. As results, we find that dose-rate does not affect the grain boundary P coverage within the range of our simulation condition and that the dependence on irradiation temperature differs remarkably from the previous results.


2020 ◽  
Vol 110 ◽  
pp. 102798
Author(s):  
KaiTai Liu ◽  
Mei Huang ◽  
JunJie Lin ◽  
HaiPeng Jiang ◽  
BoXue Wang ◽  
...  

2021 ◽  
Vol 13 (10) ◽  
pp. 5498
Author(s):  
Alvaro Rodríguez-Prieto ◽  
Mariaenrica Frigione ◽  
John Kickhofel ◽  
Ana M. Camacho

The growth of green energy technologies within the frame of the 7th Sustainable Development Goal (SDG) along with the concern about climatic changes make nuclear energy an attractive choice for many countries to ensure energy security and sustainable development as well as to actively address environmental issues. Unlike nuclear equipment (immovable goods), which are often well-catalogued and analyzed, the design and manufacturing codes and their standardized materials specifications can be considered movable and intangible goods that have not been thoroughly studied based on a detailed evaluation of the scientific and technical literature on the reactor pressure vessel (RPV) materials behavior. The aim of this work is the analysis of historical advances in materials properties research and associated standardized design codes requirements. The analysis, based on the consolidated U.S. Nuclear Regulatory Commission (NRC) Regulatory Guide (RG) 1.99 Rev.2 model, enables determination of the best materials options, corresponding to some of the most widely used material specifications such as WWER 15Kh2MFAA (used from the 1970s and 1980s; already in operation), ASME SA-533 Grade B Cl.1 (used in pressurized water reactor-PWR 2nd–4th; already in operation), DIN 20MnMoNi55 and DIN 22NiMoCr37 (used in PWR 2nd–4th) as well as ASTM A-336 Grade F22V (current designs). Consequently, in view of the results obtained, it can be concluded that the best options correspond to recently developed or well-established specifications used in the design of pressurized water reactors. These assessments endorse the fact that nuclear technology is continually improving, with safety being its fundamental pillar. In the future, further research related to the technical heritage from the evolution of materials requirements for other clean and sustainable power generation technologies will be performed.


2021 ◽  
Vol 527 ◽  
pp. 167698
Author(s):  
Xuejiao Wang ◽  
Wenjiang Qiang ◽  
Guogang Shu ◽  
Junwei Qiao ◽  
Yucheng Wu

Author(s):  
Hsoung-Wei Chou ◽  
Chin-Cheng Huang ◽  
Bo-Yi Chen ◽  
Hsien-Chou Lin ◽  
Ru-Feng Liu

The fracture probability of a boiling water reactor pressure vessel for a domestic nuclear power plant in Taiwan has been numerically analyzed using an advanced version of ORNL’s FAVOR code. First, a model of the vessel beltline region, which includes all shell welds and plates, is built for the FAVOR code based on the plant specific parameters of the reactor pressure vessel. Then, a novel flaw model which describes the flaw types of surface breaking flaws, embedded weld flaws and embedded plate flaws are simulated along both inner and outer vessel walls. When conducting the fracture probability analyses, a transient low temperature over-pressure event, which has previously been shown to be the most severe challenge to the integrity of boiling water reactor pressure vessels, is considered as the loading condition. It is found that the fracture occurs in the fusion-line area of axial welds, but with only an insignificant failure probability. The low through-wall cracking frequency indicates that the analyzed reactor pressure vessel maintains sufficient stability until either the end-of-license or for doubling of the present license of operation.


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