Analysis of the impact of random summing on passive assay of pebble bed reactor fuel using gamma-ray spectrometry

2007 ◽  
Vol 579 (1) ◽  
pp. 297-300
Author(s):  
J. Chen ◽  
A.I. Hawari
Keyword(s):  
Gamma Ray ◽  
Reactor Fuel ◽  
Gamma Ray Spectrometry ◽  
Pebble Bed ◽  
Pebble Bed Reactor ◽  
The Impact

Assessment of on-line burnup monitoring of pebble bed reactor fuel using passive gamma-ray spectrometry

2002 ◽  
Vol 49 (3) ◽  
pp. 1249-1253 ◽  
Author(s):  
A.I. Hawari ◽  
Jianwei Chen ◽  
Bingjing Su ◽  
Zhongxiang Zhao
Keyword(s):  
Gamma Ray ◽  
Reactor Fuel ◽  
Gamma Ray Spectrometry ◽  
Pebble Bed ◽  
Pebble Bed Reactor ◽  
On Line

Gamma-ray spectrometry observations to monitor a presumed meteoritic signature at Maâdna crater (Talemzane, Algeria)

2020 ◽  
Author(s):  
Atmane Lamali ◽  
Lamine Hamai ◽  
Sid Ahmed Mokhtar ◽  
Abdelkrim Yelles-chaouche ◽  
Abdeslam Abtout ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Sedimentary Rocks ◽  
Clay Content ◽  
Gamma Ray Spectrometry ◽  
Gamma Spectrometer ◽  
Geophysical Method ◽  
Impact Cratering ◽  
High Level ◽  
The Impact

<p>By measuring changes in radioelement concentrations, gamma-ray spectrometry is increasingly emerging as an efficient geophysical method that allows such changes to be geologically mapped according to lithology and soil type. At Maâdna crater in southern Algeria, this method has been used to monitor any changes in the composition of the target rocks that may be associated with the impact cratering process. For this purpose, several measurements were carried out in situ using a portable field gamma spectrometer. As a result, most predominantly calcareous surface lithologies, exposed on the rim and flanks of the crater, showed a very low emitted radiometric response over the three channels (K, Th, U). However, no more than 90 Cps were counted both inside and outside the crater. Such a rate is indeed expected in sedimentary rocks with low clay content, and this remains valid, as long as other exogenous mineralogical enrichments are excluded. On the other hand, the contoured radioelement concentrations maps, have demonstrated an anomalous enhanced gamma radiation levels of potassium-dominated peaks over the central part of the crater and in the surrounding wadis. Nevertheless, the central potassium anomaly is well correlated with the shallower magnetic one that has been described in previous studies (see e.g. Lamali et al., 2016). Therefore, either near the surrounding wadis or in the central part of this crater, this anomalously high level of radioactivity may be linked to an accumulation of later altered deposits. Consequently, there are no objective criteria to link these results to an impact event occurring at the Maâdna structure, similar to what was done at the Serra da Cangalha crater (Vasconcelos et al., 2012).</p>

Assessment of on-line burnup monitoring of pebble bed reactor fuel by passive neutron counting

2006 ◽  
Vol 48 (7) ◽  
pp. 686-702 ◽  
Author(s):  
Bingjing Su ◽  
Zhongxiong Zhao ◽  
Jianwei Chen ◽  
Ayman I. Hawari
Keyword(s):  
Reactor Fuel ◽  
Pebble Bed ◽  
Pebble Bed Reactor ◽  
Neutron Counting ◽  
On Line

scholarly journals Investigation on the mechanism of enhancing heat transfer in a pebble bed by adding in the non-fixed number of smaller-sized spheres

2021 ◽  
Vol 321 ◽  
pp. 04001
Author(s):  
Leisheng Chen ◽  
Jiahao Zhao ◽  
Yuejin Yuan ◽  
Jaeyoung Lee
Keyword(s):  
Heat Transfer ◽  
Surface Area ◽  
Fixed Number ◽  
Transfer Coefficients ◽  
Pebble Bed ◽  
Pebble Bed Reactor ◽  
Heat Transfer Coefficients ◽  
Contact Points ◽  
Enhancing Heat Transfer ◽  
The Impact

Enhancing heat transfer in the pebble bed reactor could reduce the surface temperatures and lower the possibility of forming hot-spots. The effectiveness of inserting a smaller sphere into a structured pebble bed on optimizing the heat transfer has been confirmed, and yet, the mechanism of heat transfer enhancement is still not fully understood. The impact of the quantity and size of the small spheres on the heat transfer characteristics has been investigated in this study and the mechanism of enhancement was analyzed. It was found that: (1) When the volume or the surface area of the inserted sphere was kept the same, the overall heat transfer coefficients (HTC) of the pebble bed in case 2 or case 3 respectively demonstrated 1.4% or 2.8% higher than that of the bed in case 1; (2) the overall HTC showed an increasing trend with the decreasing ratio of the surface area to the volume; (3) the varying trends of local HTCs along the designated direction were similar among 3 cases and the strongest heat transfer positions were found near pebble-sphere contact points. Such findings will help to design a better pebble bed core.

scholarly journals Spatial variability of 137Cs in the soil of Belgrade region (Serbia)

2014 ◽  
Vol 68 (4) ◽  
pp. 449-455 ◽  
Author(s):  
Ljiljana Jankovic-Mandic ◽  
Ranko Dragovic ◽  
Milan Djordjevic ◽  
Maja Djolic ◽  
Antonije Onjia ◽  
...  
Keyword(s):  
Chernobyl Accident ◽  
Gamma Ray ◽  
Specific Activity ◽  
High Mobility ◽  
Absorbed Dose ◽  
Deposition Process ◽  
Gamma Ray Spectrometry ◽  
Dose Rates ◽  
Specific Activities ◽  
The Impact

Among radionuclides in the soil deposited after Chernobyl accident, 137Cs poses considerable environmental and radiological problems because of its relatively long half-life (30.17 y), its abundance in the fallout, high mobility and similarity to potassium as the major plant nutrient. In this study the samples of undisturbed surface soil (n=250) were taken from 70 regions in Belgrade, during 2006-2010. The specific activities of 137Cs were measured by gamma-ray spectrometry. Based on obtained results external effective dose rates were calculated according to the internationally accepted activity to dose rate conversion equations. The specific activities of 137Cs were geographically mapped. The presence of 137Cs has been detected in all soil samples, with high variability of its specific activity, ranging from 3 Bq kg-1 to 87 Bq kg-1. The mean specific activity of 137Cs was 23 Bq kg-1 and the corresponding absorbed dose was 1.5 nSv h-1. The observed range reflects the inhomogeneity of the deposition process following the Chernobyl accident. It could also be attributed to topographic differences and spatial differences in physicochemical and biological soil properties, soil type and vegetation cover. The results of the present study could be valuable database for future estimations of the impact of radioactive pollution.

scholarly journals Radiological impact of phosphogypsum surface application in a no-till system in Southern Brazil

2010 ◽  
Vol 45 (12) ◽  
pp. 1456-1464 ◽  
Author(s):  
Nivea Maria Piccolomini Dias ◽  
Eduardo Fávero Caires ◽  
Luiz Fernando Pires ◽  
Márcio Arruda Bacchi ◽  
Elisabete Aparecida de Nadai Fernandes
Keyword(s):  
Field Experiment ◽  
Human Health ◽  
Gamma Ray ◽  
Gamma Ray Spectrometry ◽  
Southern Brazil ◽  
Small Reduction ◽  
No Till ◽  
Hpge Detectors ◽  
Radiological Impact ◽  
The Impact

The objective of this work was to determine the impact of phosphogypsum application on 226Ra and 228Ra activities in the soil and on their accumulation in soybean grains. A field experiment was carried out in Paraná state, Brazil, on a loamy Typic Hapludox, under no-till system, with increasing phosphogypsum rates: 4, 8, and 12 Mg ha-1. GammA ray spectrometry was carried out using HPGe detectors with 45 and 10% relative efficiencies, for soybean grains and soil, respectively. No increment of 226Ra and 228Ra activities was observed due to the increase in phosphogypsum rates in the soil, and a small reduction was noticed in the grains. Average values found for 226Ra and 228Ra activities were 37 and 57 Bq kg-1 in the soil and 1.44 and 3.19 Bq kg-1 in soybean grains. The application of phosphogypsum for no-till soybean production is a safe practice regarding the risks of radiation damage to human health

Sign in / Sign up

Export Citation Format

Share Document