Study on the uranium (U(Ⅵ)) adsorption stability of high-dose γ-ray-irradiated clay

2022 ◽  
pp. 110102
Author(s):  
Jianfeng Cheng ◽  
Runqiu Gu ◽  
Panqing He ◽  
Yuelong Pan ◽  
Yangchun Leng ◽  
...  
Keyword(s):  
High Dose ◽  
Γ Ray

Effect of high dose γ-ray irradiation on GaAs p-i-n photodetectors

2015 ◽  
Vol 785 ◽  
pp. 93-98 ◽  
Author(s):  
V.K. Dixit ◽  
Shailesh K. Khamari ◽  
Sapna Manwani ◽  
S. Porwal ◽  
K. Alexander ◽  
...  
Keyword(s):  
High Dose ◽  
Γ Ray

Effect of γ-ray irradiation on performance of LiNbO(3)-based piezoelectric vibration sensors

2021 ◽  
Author(s):  
Huifen Wei ◽  
Wenping Geng ◽  
Kaixi Bi ◽  
Tao Li ◽  
Xiangmeng Li ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Extreme Environments ◽  
Theoretical Work ◽  
High Dose ◽  
Mems Devices ◽  
Micro Electro Mechanical Systems ◽  
Vibration Sensors ◽  
Irradiation Dosage ◽  
Gamma Ray Irradiation ◽  
Γ Ray

Abstract LiNbO3 (LN)-based micro-electro-mechanical systems (MEMS) vibration sensors exhibit giant prospection in extreme environments, where exist a great amount of irradiation. However, to the best of our knowledge, it is still unknown whether the irradiation affects the performance of LN-based piezoelectric MEMS sensors. Based on this consideration, it is necessary to model the irradiation environment to investigate the effect of high dosage irradiation on LN-based vibration sensors. Firstly, the theoretical work is done to study the Compton Effect on the Gamma-ray irradiation with Co-60 source. After irradiation, X-ray diffraction (XRD) characterization was performed to verify the effect of irradiation on the crystalline of LN thin film. Meanwhile, the performances of output voltages on the five MEMS devices under various dosage of irradiation are compared. As a result, a neglected shift of 0.02 degrees was observed from the XRD image only under maximum irradiation dosage of 100 Mrad(Si). Moreover, the output voltages of cantilever-beam vibration sensors decrease by 3.1%. Therefore, it is verified that the γ-ray irradiation has very little influence on the LN-based MEMS vibration sensors, which have great attraction on the materials and sensors under high-dose irradiation.

Measurements of the High Dose Rate Profiles Inside a Shutdown CANDU® Reactor

2012 ◽  
Vol 1 (1) ◽  
pp. 27-34
Author(s):  
C. Jewett ◽  
J. Chow ◽  
D. Comeau ◽  
G. Jonkmans ◽  
B. Smith ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Dose Rate ◽  
High Dose Rate ◽  
Measured Data ◽  
High Dose ◽  
Dose Rates ◽  
Diode Detector ◽  
Γ Ray ◽  
Rate Profile

The positions of the components of a reactor can change over time, due to radiation damage, sagging, etc. Thus, it is important to determine their positions. To satisfy this requirement of the staff at the Point Lepreau Generating Station, a method to determine the positions of reactor components has been developed and demonstrated. This method combines the use of dose rate measurements and Monte Carlo simulations. It first involves measuring the high γ-ray dose rates as a function of position within a reactor. Then it entails comparing these measurements with Monte Carlo simulations. In order to perform such measurements, a silicon diode detector and a scan drive system have been developed. In 2009, measurements of the γ-ray dose rate profile of the shut down Point Lepreau Generating Station reactor were conducted. By comparing the locations of the local peaks in the dose rate data, it was possible to determine the distances between the steel reactor components. The measured data were then compared with Monte Carlo simulations to determine how precisely one could locate the positions of the adjuster rods. Using this technique, it was found that the retracted adjuster rods were 440 ± 60 mm below their designed positions.

scholarly journals Diminished or inversed dose-rate effect on clonogenic ability in Ku-deficient rodent cells

2020 ◽  
Author(s):  
Hisayo Tsuchiya ◽  
Mikio Shimada ◽  
Kaima Tsukada ◽  
Qingmei Meng ◽  
Junya Kobayashi ◽  
...  
Keyword(s):  
Cell Survival ◽  
Dose Rate ◽  
Biological Effects ◽  
Severe Combined Immunodeficiency ◽  
High Dose Rate ◽  
Rate Effect ◽  
High Dose ◽  
Γ Ray ◽  
Clonogenic Cell ◽  
Dose Rate Effect

Abstract The biological effects of ionizing radiation, especially those of sparsely ionizing radiations like X-ray and γ-ray, are generally reduced as the dose rate is reduced. This phenomenon is known as ‘the dose-rate effect’. The dose-rate effect is considered to be due to the repair of DNA damage during irradiation but the precise mechanisms for the dose-rate effect remain to be clarified. Ku70, Ku86 and DNA-dependent protein kinase catalytic subunit (DNA-PKcs) are thought to comprise the sensor for DNA double-strand break (DSB) repair through non-homologous end joining (NHEJ). In this study, we measured the clonogenic ability of Ku70-, Ku86- or DNA-PKcs-deficient rodent cells, in parallel with respective control cells, in response to high dose-rate (HDR) and low dose-rate (LDR) γ-ray radiation (~0.9 and ~1 mGy/min, respectively). Control cells and murine embryonic fibroblasts (MEF) from a severe combined immunodeficiency (scid) mouse, which is DNA-PKcs-deficient, showed higher cell survival after LDR irradiation than after HDR irradiation at the same dose. On the other hand, MEF from Ku70−/− mice exhibited lower clonogenic cell survival after LDR irradiation than after HDR irradiation. XR-V15B and xrs-5 cells, which are Ku86-deficient, exhibited mostly identical clonogenic cell survival after LDR and HDR irradiation. Thus, the dose-rate effect in terms of clonogenic cell survival is diminished or even inversed in Ku-deficient rodent cells. These observations indicate the involvement of Ku in the dose-rate effect.

scholarly journals Hydrazine Radiolysis by Gamma-Ray in the N2H4–Cu+–HNO3 System

2021 ◽  
Vol 22 (14) ◽  
pp. 7376
Author(s):  
Naon Chang ◽  
Huijun Won ◽  
Sangyoon Park ◽  
Heechul Eun ◽  
Seonbyeong Kim ◽  
...  
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Gamma Ray ◽  
Uv Spectroscopy ◽  
Radiolysis Product ◽  
Decomposition Mechanism ◽  
Irradiation Condition ◽  
High Dose ◽  
Hno3 Solution ◽  
Γ Ray

Radiolysis of chemical agents occurs during the decontamination of nuclear power plants. The γ-ray irradiation tests of the N2H4–Cu+–HNO3 solution, a decontamination agent, were performed to investigate the effect of Cu+ ion and HNO3 on N2H4 decomposition using a Co-60 high-dose irradiator. After the irradiation, the residues of N2H4 decomposition were analyzed by Ultraviolet-visible (UV) spectroscopy. NH4+ ions generated from N2H4 radiolysis were analyzed by ion chromatography. Based on the results, the decomposition mechanism of N2H4 in the N2H4–Cu+–HNO3 solution under γ-ray irradiation condition was derived. Cu+ ions form Cu+N2H4 complexes with N2H4, and then N2H4 is decomposed into intermediates. H+ ions and H● radicals generated from the reaction between H+ ion and eaq− increased the N2H4 decomposition reaction. NO3− ions promoted the N2H4 decomposition by providing additional reaction paths: (1) the reaction between NO3− ions and N2H4●+, and (2) the reaction between NO● radical, which is the radiolysis product of NO3− ion, and N2H5+. Finally, the radiolytic decomposition mechanism of N2H4 obtained in the N2H4–Cu+–HNO3 was schematically suggested.

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