Table M.4 Radioactive Nuclides Used in Radiotherapy

AbstractThe results of the specific activities of232Th,226Ra and40K measured in samples of commonly used building materials in Bosnia and Herzegovina are presented. Measurements were performed by gamma-ray spectrometer with coaxial HPGe detector. The surface radon exhalation and mass exhalation rates for selected building materials were also measured. The determined values of specific activities were in range from 3.16±0.81 Bq kg−1to 64.79±6.16 Bq kg−1for232Th, from 2.46±0.95 Bq kg−1to 53.89 ±3.67 Bq kg−1for226Ra and from 28.44±7.28 Bq kg−1to 557.30±93.38 Bq kg−1for40K. The radium equivalent activity, the activity concentration index, the external and internal hazard indices as well as the absorbed dose rate in indoor air and the corresponding annual effective dose, due to gamma-ray emission from the radioactive nuclides in the building material, were evaluated in order to assess the radiation hazards for people. The measured specific activities of the natural radioactive nuclides in all investigated building materials were compared with the published results for building materials from other European countries. It can be noted that the results from this study are similar to the data for building materials from neighbouring countries and for building materials used in the EU Member States. The radiological hazard parameters of the building materials were all within the recommended limits for safety use.

Download Full-text

A Conceptual Approach to Eliminate Bypass Release of Fission Products by In-Containment Relief Valve under SGTR Accident

Science and Technology of Nuclear Installations ◽

10.1155/2018/5936214 ◽

2018 ◽

Vol 2018 ◽

pp. 1-12

Author(s):

Taeseok Kim ◽

Wonjun Choi ◽

Joongoo Jeon ◽

Nam Kyung Kim ◽

Hoichul Jung ◽

...

Keyword(s):

Steam Generator ◽

Nuclear Power ◽

Power Plants ◽

Fission Products ◽

Mitigation Strategies ◽

Severe Accident ◽

Base Case ◽

Conceptual Approach ◽

Relief Valve ◽

Radioactive Nuclides

During a hypothesized severe accident, a containment building is designed to act as a final barrier to prevent release of fission products to the environment in nuclear power plants. However, in a bypass scenario of steam generator tube rupture (SGTR), radioactive nuclides can be released to environment even if the containment is not ruptured. Thus, thorough mitigation strategies are needed to prevent such unfiltered release of the radioactive nuclides during SGTR accidents. To mitigate the consequence of the SGTR accident, this study was conducted to devise a conceptual approach of installing In-Containment Relief Valve (ICRV) from steam generator (SG) to the free space in the containment building and it was simulated by MELCOR code for numerical analysis. Simulation results show that the radioactive nuclides were not released to the environment in the ICRV case. However, the containment pressure increased more than the base case, which is a disadvantage of the ICRV. To minimize the negative effects of the ICRV, the ICRV linked to Reactor Drain Tank (RDT) and cavity flooding was performed. Because the overpressurization of containment is due to heat of ex-vessel corium, only cavity flooding was effective for depressurization. The conceptual design of the ICRV is effective in mitigating the SGTR accident.

Download Full-text

Radioactive nuclides in phosphogypsum from the lowveld region of South Africa

South African Journal of Science ◽

10.17159/sajs.2016/20150102 ◽

2016 ◽

Vol Volume 112 (Number 1/2) ◽

Cited By ~ 6

Author(s):

Xolani Msila ◽

Frans Labuschagne ◽

Werner Barnard ◽

David G. Billing ◽

◽

...

Keyword(s):

South Africa ◽

Concentration Index ◽

Building Materials ◽

Activity Concentration ◽

Final Decision ◽

Hazard Indices ◽

Naturally Occurring ◽

Radioactive Nuclides ◽

Radium Equivalent ◽

Activity Concentration Index

Abstract We evaluated the suitability of phosphogypsum from the Lowveld region of South Africa (LSA), for the manufacturing of building materials, with reference to (1) the National Nuclear Regulator Act 47 of 1999 and (2) the radioactivity associated risks as quantified in terms of the external and internal hazard indices, the activity concentration index and the radium equivalent. The distribution of radioactive nuclides in the LSA phosphogypsum was also examined. Analyses of 19 samples of the phosphogypsum show that phosphogypsum contains lower activity concentrations of naturally occurring radioactive nuclides of uranium and thorium and their progeny than the 500 Bg/kg limit set for regulation in South Africa. The potassium-40 (40K) activity concentration was below the minimum detectable amount of 100 Bq/kg. The values obtained for external and internal hazard indices and the activity concentration index were: 2.12 0.59, 3.44 0.64 and 2.65 0.76 respectively. The calculated radium equivalent Raeq was 513 76Bq/kg. The final decision regarding phosphogypsum’s suitability for use as a building material should consider scenarios of use.

Download Full-text