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Mao Y.,State Nuclear Power Plant Service Company | Pei C.,University of Tokyo
Zhongguo Jixie Gongcheng/China Mechanical Engineering

A non-contact ultrasonic testing system using a pulsed laser for ultrasound generation and an EMAT for ultrasound detection were developed for the inner crack inspection. To avoid the laser-induced ablation damage on the specimen, thermo-elastic model was used to excite ultrasound, the EMAT probe was used to receive signals. The EMAT in plane and EMAT out of plane were used to study the transversed wave and longitudinal wave spreading in the half aluminum test block respectively. Finally, combining the shadow method, the test system was used to measure the crack on the back of the specimen, the crack depth and the actual depth are very close. It is shown that, in the thermoelastic mode, the laser excitation, the method for EMAT probe received signals are feasible in the inspection of cracks. Source

Fan Z.,State Nuclear Power Plant Service Company | Xu H.,East China University of Science and Technology | Li D.,East China University of Science and Technology | Zhang L.,East China University of Science and Technology | Liao L.,East China University of Science and Technology
Procedia Engineering

A nanostructured surface layer was fabricated on 35# type carbon steel plate by using ultrasonic impact treatment (UIT) technique, The micro-structural features of the surface layer produced by UIT were characterized by optical microscopy (OM) observations, X-ray diffraction (XRD) and transmission electron microscopy (TEM), and hardness measurement was carried out in order to examine the hardness variation along the depth. Experimental results showed that the thickness of the plastic deformation layer varies from a few to about 100μm depending on the duration of UIT. Obvious grain refinement was observed and the gain size was about 10nm in the top surface layer. After UIT, the micro-hardness of the surface layer was enhanced significantly compared with that of the original sample, and the hardness increased when the duration of UIT increased. © 2011 Published by Elsevier Ltd. Source

Wang Z.,East China University of Science and Technology | Wang Z.,State Nuclear Power Plant Service Company | Wang F.,East China University of Science and Technology | Cao J.,East China University of Science and Technology | Wang J.,East China University of Science and Technology
Fuel Processing Technology

Catalytic pyrolysis of pine wood was carried out in a fixed-bed reactor heated slowly from room temperature to 700 °C under a stream of purging argon to examine the effects of the physically mixed K2CO3 or Ca(OH)2 on the pyrolysis behaviors. K2CO3 demonstrated a stronger catalysis for decomposition of hemicellulose, cellulose and lignin constituents, leading to the reduced yield of liquid product in conjunction with the increased yields of gaseous and char products because of the promoted secondary reactions of liquid product. With the addition of 17.7 wt.% of K2CO3, none of saccharides, aldehydes and alcohols was formed and the formation of acids, furans and guaiacols was substantially reduced, whereas the yields of alkanes and phenols were increased. Potassium led to an increase in the cumulative yields of H2, CO2 and CO at 700 °C. Ca(OH)2 somewhat promoted the decomposition of cellulose and lignin constituents, and the effect of Ca(OH)2 on the yields of liquid and char was opposite to that of K2CO3. With the addition of 22.2 wt.% Ca(OH)2, some groups of liquid product such as acids and aldehydes disappeared completely and the yields of saccharides, furans and guaiacols were somewhat reduced, while the yield of alcohols was remarkably increased in contrast to the result of K 2CO3. The addition of Ca(OH)2 did not significantly change the total yield of gaseous product at 700 °C but enhanced the yield of H2. © 2009 Elsevier B.V. All rights reserved. Source

Li Y.,State Nuclear Power Plant Service Company | Yin X.-Y.,State Nuclear Power Plant Service Company
Hedianzixue Yu Tance Jishu/Nuclear Electronics and Detection Technology

As an important fuel leakage inspection technology, the sipping detection technology based on the radioactive isotope inspection has been widely used during the nuclear power station refueling overhaul. In order to thoroughly research and command it, four frequently used sipping inspection methods have been described and compared, it will be served as the technical reference for the development of universal and efficient sipping system suitable for the domestic nuclear power plant. Source

Wang J.,CAS Shenyang Institute of Metal Research | Li X.,CAS Shenyang Institute of Metal Research | Li X.,State Nuclear Power Plant Service Company | Huang F.,CAS Shenyang Institute of Metal Research | And 2 more authors.

Corrosion behaviors of UNS N06690TT and N08800SN in simulated pressurized water reactor (PWR) primary water containing three concentrations of dissolved oxygen (DO) was studied by open-circuit potential (OCP), electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), x-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM). These results have shown that DO in simulated PWR primary water produces a strong effect on Cr dissolution. At DO < 0.01 ppm, the electrochemical impedance of N06690TT at low frequency gradually increases and becomes larger than that of N08800SN, and N06690TT shows slightly better corrosion resistance than N08800SN. At DO ≥ 0.1 ppm, the electrochemical impedance of N06690TT at low frequency rapidly decreases and becomes lower than that of N08800SN with the increase of immersion time; N08800SN shows much better corrosion resistance than N06690TT. The spinel oxides NiFe2O4 or Fe 3O4 can form in the inner oxide layer on N08800SN due to relatively balanced ratio of Fe, Ni, which leads to the relatively stable corrosion resistance. Therefore, when DO in PWR primary water is 0.1 ppm or more, it is more suitable to choose N08800SN rather than N06690TT as the steam generator (SG) tubing materials. © 2014, NACE International. Source

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