Recent Developments in Small Punch Testing: Interlaboratory Tests and Standardization

2019 ◽  
Vol 795 ◽  
pp. 466-472
Author(s):  
Ondrej Bursik ◽  
Radim Kopřiva ◽  
Petra Petelova ◽  
Barbora Maresova

Small specimen testing techniques are developed mainly for characterization of the structural materials with a limited volume of material. One of the most used miniature specimen testing techniques is the small punch (SP) test which is based on the testing of thin disc shaped samples. From the operational point of view SP test can be considered as a non-destructive method, because the material volume cut from industrial component is not diminishing its structural integrity. This benefit can be significant for the use in nuclear power generation sector, as many components are considered as irreplaceable and conventional testing techniques are not applicable for the determination of current mechanical properties. Although SP testing has been used for more than 40 years, there are still many research and development subjects. The article describes the SP test method as a suitable supplement to classical methods for evaluating mechanical properties that are fundamental for the nuclear power plant integrity and operational lifetime assessment processes. Main part of the article is focused on the current status of ASTM and EN standardization processes that are essential for possible usage in nuclear power plant integrity assessment and other industrial areas as well. Paper also describes results of the ongoing interlaboratory study which task is to determine repeatability and reproducibility of results obtained from material testing.

2021 ◽  
Author(s):  
Hoseon Choi ◽  
Seung Gyu Hyun

<p>According to strict criteria step by step for site selection, design, construction and operation, the seismic safety of nuclear power plant (NPP) sites in South Korea are secured by considering design basis earthquake (DBE) level capable of withstanding the maximum ground motions that can occur on the site. Therefore, it is intended to summarize DBE level and its evaluation details for NPP sites in several countries.</p><p>Similar but different terms are used for DBE from country to country, i.e. safe shutdown earthquake (SSE), design earthquake (DE), SL2, Ss, and maximum calculated earthquake (MCE). They may differ when applied to actual seismic design process, and only refer to approximate comparisons. This script used DBE as a representative term, and DBE level was based on horizontal values.</p><p>The DBE level of NPP sites depends on seismic activity of the area. Japan and Western United States, where earthquakes occur more frequently than South Korea, have high DBE values. The DBE level of NPP sites in South Korea has been confirmed to be similar or higher compared to that of Central and Eastern Unites Sates and Europe, which have similar seismic activity.</p>


2021 ◽  
Author(s):  
Ichiro Tanaka ◽  
Atsushi Yamaguchi ◽  
Kenji Kikuchi ◽  
Nobuo Niimura ◽  
Yume Saeki ◽  
...  

<p>The radioactive cesium (<sup>134</sup>Cs and <sup>137</sup>Cs), which originated from the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident, has remained in the soil and on plants as water-insoluble microparticles (termed as CsMPs) to some extent, and maintained relatively high radioactivity levels in the district. However, it has been reported that the radioactive Cs has been absorbed by plants. To interpret this phenomenon, the authors investigated CsMPs to determine if they become soluble during filtration and dialysis experiments. Moreover, other physical properties, such as mechanical properties and thermal stability, were observed during the course of the relevant experiments. These properties can be obtained by using carbonized charcoal litter with CsMPs. And simple and economic decontamination trials of the soil were performed by sieving after drying and roughly crushing.</p>


2018 ◽  
Vol 68 (3) ◽  
pp. 167-182 ◽  
Author(s):  
Saha Sabhasachi ◽  
Roy Koushik ◽  
Roy Souvik ◽  
Rahman Md. Asfakur ◽  
Hasan Md. Zahid

AbstractIn the present world, nuclear energy is a must need for various purposes. The main cause of nuclear energy is because of the increasing energy demand, which is not possible to provide by using convenient energy generation. Bangladesh is a lower income country and the energy sector is not so developed here though there is a very high demand for energy. Rooppur Nuclear Power Plant is the only one nuclear generation plant which can provide this kind of huge energy within a very short time. This paper mainly depicts the ins and outs of this plant and discusses it’s feasibility in Bangladesh. It also focuses on the worlds various power generation methods and comprises it with nuclear energy generation. A detailed technical brief is presented in this paper along with advantages, location selection, financial and environmental impacts. This will help researchers to do further researches about nuclear energy in Bangladesh.


2013 ◽  
Vol 644 ◽  
pp. 56-59
Author(s):  
Jin Yang Li ◽  
Hong Xia ◽  
Shou Yu Cheng

All kinds of sensor with mechanical properties often can go wrong in nuclear power plant. In this kind of situation, it puts forward a kind of active fault tolerant control method based on the improved BP neural network. Firstly, the method will train sensor by BP neural network. Secondly, it will be established dynamic model bank in all kinds of running state. The system will be detected by using BP neural network real time. When the sensor goes wrong, it will be controled by reconstruction. Taking pressurizer water-level sensor as the case, a simulation experiment was performed on the nuclear power plant simulator. The results showed that the proposed method is valid for the fault tolerant control of sensor in nuclear power plant.


2007 ◽  
Vol 345-346 ◽  
pp. 1357-1360
Author(s):  
Hyun Su Kim ◽  
Tae Eun Jin ◽  
Hong Deok Kim ◽  
Han Sub Chung ◽  
Yoon Suk Chang ◽  
...  

Steam generator in a nuclear power plant is huge heat exchanger that transfers heat from reactor to make steam to drive turbine-generator. Failure of the steam generator tubes can result in the release of fission products to the secondary side. Therefore, accurate integrity assessment of the cracked steam generator tubes is of great importance for maintaining the safety of the nuclear power plant. This paper provides limit loads for circumferential through-wall cracks in steam generator tubes under combined internal pressure and bending loads. Such limit loads are developed on the basis of three dimensional finite element analyses assuming elastic-perfectly plastic material behavior. As for the crack location, both the top of the tubesheet and U-bend regions are considered. The analysis results can be directly applied to the practical integrity assessment of cracked steam generator tubes, because the comparison between experimental data and FE results shows a very good agreement.


Author(s):  
Ichiro Tanaka ◽  
Atsushi Yamaguchi ◽  
Kenji Kikuchi ◽  
Masakazu Komatsuzaki ◽  
Ichiro Tanaka ◽  
...  

Most of the radioactive cesium (134Cs and 137Cs), which originated from the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident, has remained in the soil and on plants as water-insoluble microparticles (termed as CsMPs) and maintained relatively high radioactivity levels in the district. However, it has been reported that the radioactive Cs has been absorbed by plants. To interpret this phenomenon, the authors investigated CsMPs to determine if they become soluble during filtration and dialysis experiments. Moreover, other physical properties, such as mechanical properties and thermal stability, were observed during the course of the relevant experiments. These properties can be obtained by using carbonized charcoal litter with CsMPs.


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