Author : Yu-Yeung Chiu
Publisher : Open Dissertation Press
ISBN 13 : 9781374667204
Total Pages : pages
Book Rating : 4.6/5 (672 download)
Book Synopsis Environmental Radiation Monitoring at the Low Level Radioactive Waste Storage Facility in Siu a Chau and Development of a Particle Dispersion Model in Marine Environment by : Yu-Yeung Chiu
Download or read book Environmental Radiation Monitoring at the Low Level Radioactive Waste Storage Facility in Siu a Chau and Development of a Particle Dispersion Model in Marine Environment written by Yu-Yeung Chiu and published by Open Dissertation Press. This book was released on 2017-01-27 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation, "Environmental Radiation Monitoring at the Low Level Radioactive Waste Storage Facility in Siu A Chau and Development of a Particle Dispersion Model in Marine Environment" by Yu-yeung, Chiu, 趙汝揚, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: Abstract of thesis entitled ENVIRONMENTAL RADIATION MONITORING AT THE LOW LEVEL RADIOACTIVE WASTE STORAGE FACILITY IN SIU A CHAU AND DEVELOPMENT OF A PARTICLE DISPERSION MODEL IN MARINE ENVIRONMENT Submitted by Chiu Yu Yeung for the degree of Master of Philosophy at The University of Hong Kong in August 2006 The low-level radioactive waste storage facility (LRWF) on the remote island of Siu A Chau, Hong Kong SAR, commenced operation in mid 2005 and operator was required to transfer the then existing low-level radioactive wastes from the Queen's Road East tunnels storage to the LRWF within the first operational year. In this year, monitoring of the facility was carried out by us in order to ensure that there is no long-term adverse effect to the environment near the LRWF. An environmental survey was made before and after the LRWF commenced operation. Large quantities of baseline samples had been collected before the operation to find out the normal fluctuation of radioactivities in environmental samples. Environmental samples included soil, sand, grass, seawater, airborne particulate filter and ambient gamma dose rate. Then, environmental samples were taken regularly after the LRWF commenced operation. The samples were collected monthly for the first 6 months and bi-monthly for another 6 months. When no problem was encountered, the sampling schedule was changed to yearly. The gamma emitters, gross alpha and beta activities in the environmental samples were analyzed. The radioactivities in environmental samples were compared individually with the respective investigation levels, which were 3 times of standard deviation above the average radioactivities in baseline samples ( x+ 3σ ). When the sample activity exceeds the investigation level, some investigations were carried out. Most of the samples were normal but the radioactivities in a few sand samples and airborne particulate filters were found to be higher than investigation levels, and were caused by sample variances and/or seasonal variation. Also, the ambient gamma dose rate was analyzed by two-tailed t-test. The results showed no significant difference between mean of baseline ambient gamma dose rate and mean of the ambient gamma dose rate after the LRWF commenced operation. Moreover, a particle dispersion model in marine environment was developed to estimate dispersion of radionuclides over Sum Wan, Siu A Chau, when the liquid effluent was discharged from the facility by aquatic pathway. A preliminary experiment at Tolo Harbour and tracer experiment at Sum Wan, Siu A Chau, were carried out to verify the model. Delayed coincidence counting system was used to analyze the concentration of natural tracer, Ra-224, over Tolo Harbour. The field data agreed with the model results. A fluorescent dye, rhodamine WT, was instantaneously discharged near the discharge pipeline of the LRWF. The fluorescent dye concentrations in water samples were measured by a simple fluorometer. The low concentration samples had relatively large percentage error, making it difficult to compare with the simulation results. However, no contradiction between field experiment and the model was found. DOI: 10.5353/th_b3857361 Subjects: Radioactivity - China - Hong Kong - Measurement Low level radioactive waste disposal
