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Thesis (Masters Diploma (Technology))--Cape Technikon, Cape Town, 1995 / The development of a 200 MeV clinical proton therapy facility at the National Accelerator Centre required an interlock and control system to supervise the delivery of radiation to a patient. The interlock and control system is responsible for ensunng that nobody enters the treatment vault during an irradiation, the extraction of the beamstop devices 'from the beam-line to allow the irradiation of the patient and the insertion of those beam-stop devices when an error condition is detected. Because of its nature, the interlock and control system should be designed so that in the event of an error condition being detected, it should fail to a safe state. This is achieved by modelling the interlock and control system with an appropriate modeling method. This thesis describes a graphical modelling method called Petri-nets, which was used to model the system, and the software developed from the model.

Thesis (MPH. ) --University of Limpopo, 2014 / This dissertation reports on findings from a qualitative research that sought to investigate adherence and compliance to radiation safety protocols by radiographers and dental professionals in the Waterberg District. The study also sought to determine the knowledge the participants had on the chronic ill-effects of occupational exposure to radiation, safety protocols and their professional experience in dealing with occupational exposure to radiation. Altogether 60 participants from 8 health institutions in the Waterberg district took part in the study. They were compromised of males and females with ages ranging from 22-60 years. The response rate was 75% (n=45/60). The empirical data of the study shows a consistent yet disconcerting pattern among practitioners about safety compliance, safety protocols and their understanding of long term effect of occupational exposure to radiation. Despite their impressive knowledge of X-rays being a source of ionizing radiation, the level of their understanding of ill-effects thereof was of great concern. The general failure by both professionals in complying with the most basic safety protocols is worrisome. In a nutshell, yet some of the practitioners were found to be greatly exposed to radiation, their daily practices were found not consistent with procedures dictated by the guidelines on the use of medical X-ray equipment. Overall, only 59% of radiographers always wore their dosimeters, a basic monitoring and protective tool to measure their radiation exposure. In the study, only 38% of the dentists were found to be compliant and overwhelmingly alluded this to their employers being unable to supply them with crucial protective clothing, a finding that the researcher cannot dispute as indicated in the responses by the two groups. The failure of the employer in enforcing monitoring and assuring safety to the employees, patients and the general public emerged from this study. Various non-compliance patterns could be attributed to the participants and others to the employer. Protocols as clearly stipulated in R1332 of Hazardous Substance Act 15 of 1973 and other guidelines are not adhered to.

Thesis (M.Med. (Diagnostic Radiology)) -- University of Limpopo, 2022 / BACKGROUND: Ionizing radiation is detrimental to growing cells. The potential risk of any dose of radiation in growing cells can lead to permanent damage of basic cellular structure resulting in a high risk of developing cancer in children. Therefore, paediatric doctors need sufficient knowledge to protect their patients from late effects of radiation resulting from medical use. Most studies report poor knowledge of radiation safety measures among doctors. PURPOSE: The purpose of this study is to assess the knowledge of radiation safety and radiation doses among paediatric doctors in Pietersburg and Mankweng Hospitals, Limpopo province, South Africa. OBJECTIVE: To assess the paediatric doctors’ knowledge of radiation doses used in radiological diagnostic imaging examinations, as well as their knowledge of radiation safety measures. METHODOLOGY: This is a survey of paediatric doctors in the paediatrics general ward, paediatric oncology, intensive care and neonatal units, and paediatric surgery department, at Pietersburg and Mankweng Hospitals. A self-administered questionnaire with 23 items on knowledge of radiation safety and radiation doses emitted during normal radiological examinations is used to collect the data in May 2021. Data are analysed using Statistical Package for Social Sciences (SSPS) version 26.0 software. Chi-squared test is used to analyse the relationship between variables. Analysis of variance (ANOVA) is used to analyse the differences between variables. A p value of <0.05 is considered statistically significant. A total score of 50% in each section is used to denote adequate knowledge. The result are presented in charts and tables. RESULTS: Out of 52 paediatric doctors, 47 completed the questionnaire achieving a 90.4% response rate. Majority of participants were females (n = 31; 66%). Overall, only 10 (21.2%) of the participants scored 50% and above, including three consultants, two registrars, two medical officers and one medical officer intern. Twenty-five (53.1%) participants scored 50% and above on knowledge of radiation safety. Nearly half (44.7%) of the doctors were familiar with the concept of ALARA principle in radiation dose optimisation. Three participants scored more than 50% in the knowledge of radiation doses section. Only five (10.6%) and 17 (36%) participants correctly identified MRI and ultrasound, respectively, as the radiological diagnostic modalities that do not utilize ionizing radiation. CONCUSION: The level of knowledge of radiation safety and radiation doses among the paediatric doctors are poor. A very small number of the paediatric doctors were able to identify non-ionizing radiation modalities that can be used as an alternative to reduce radiation exposure to paediatrics during radiological investigations. Paediatric doctors will benefit from courses on radiation safety and radiation doses to improve their knowledge and/or eliminate unwarranted exposure of their patients to ionizing radiation.

The effects of radiation on an operational amplifier were investigated through simulation. The μA 741 was simulated using Spice. Under normal conditions the 741 had the following properties: offset Voltage (Vos) of 0.8 mV, bias current (IB) of 27 nA, offset current (Ios) of 1 nA, and an open loop gain (A0.1.) of 112 dB. When exposed to neutron fluence of 5 x 10¹³ n/cm², these parameters changed to offset voltage of 45 mV, bias current of 1500 nA, offset current of 500 nA, and an open loop gain of 66 dB. A new circuit is proposed that provides improvements in the above parameters. The modified circuit gives a Vos of 3 mV, IB of 200 nA, Ios of 34 nA and A0.1. of 93 dB following exposure to a neutron fluence of 5 x 10¹³n/cm².

Thesis (MPH.) -- University of Limpopo, 2012

The National Council of Radiation Protection and Measurements Report No. 49, originally issued on September 15, 1976, has been the primary design guide for diagnostic x-ray structural shielding in the United States. To further protect the public from various areas of medical radiation exposure, NCRP issued Report 116 in 1987 to decrease the public exposure limits. These new limits used in conjunction with NCRP 49 to determine shielding requirements for diagnostic radiological rooms can be shown to over-shield based on current technologies and protocols. This paper explores the NCRP conservative assumptions that physicists specifying barrier requirements for diagnostic x-ray facilities normally utilize. These evaluated assumptions, which are incorporated in the methodology and attenuation data presented in NCRP Report 49 formulas, include relatively high single kVp's, a "one size fits all" workload default, and the lack of attenuation factors by the patient, the wall, and the film. In essence, an analysis of the conservative nature of NCRP 49 is demonstrated. An example of Primary and Secondary Shielding Methodology utilizing NCRP 49 and NCRP 116 dose limits is provided as well as the cost factors associated with the results. These examples are further evaluated using a Monte Carlo software program. In addition, an analysis of actual current radiographic conditions in an imaging room is performed. This is done to determine first, the actual mA utilized for specific exams; secondly, the actual mA-min weekly workload; and thirdly, the tangible exams performed per week in small and large medical facilities. Based on the information and analysis presented, this paper concludes that the formulas for NCRP 49 and NCRP 116 need to be reexamined. Furthermore, this paper also demonstrates once again that NCRP 49, utilizing NCRP 116 dose limits is extremely conservative. / Graduation date: 2004

Rapid emergency response decisions from a radiation release are necessary in order to prevent the general public from being exposed to a potential radiation hazard. A one meter exposure rate measurement is all that is necessary to establish relocation and food control areas when the ground is contaminated at the Protective Action Guide minimum response levels. With the results of these calculations, a known one meter exposure rate is all that is necessary to establish relocation and food control areas for a release from the WNP-2 commercial nuclear power plant or a release from a waste tank at the Hanford site. The calculated one meter exposure rate for WNP-2 is 1.32 ��R/hr at twenty-four hours. The calculated one meter exposure rate for the Hanford tanks is 14.97 ��R/hr. / Graduation date: 1995

iThemba LABS is a particle accelerator facility housing a radionuclide production facility that uses a 66 MeV proton beam to produce radionuclides for medical and industrial use. Ionising radiation is produced by a variety of sources at Themba LABS. Ionising is a health hazard. High doses can cause acute radiation syndrome, i.e. "radiation sickness". Lower doses cannot cause acute symptom, but carry a risk of radiation-related cancer. Ionising radiation is also detrimental to materials, and can damage polymers and lubricants e.g. Shielding is used to reduce radiation levels to values that should be safe for the intended level of human occupancy. Shield performance is vital to human health and the life expectancy of polymers and lubricants, so that quality management in shield design is very important. However, until 2003, there has been no formal system at iThemba LABS to evaluate and improve all radiation shield designs and layouts from a radiation protection perspective. This study deals with evaluating and redesigning radiation shielding in the radionuclide production facility of iThemba LABS. There are several designs and layouts in the radionuclide production building of iThemba LABS that lead to unnecessary exposure of personnel to ionising radiation. The shielding in these areas are sub-standard. Performance criteria for radiation shields are developed. Inadequate radiation shields are identified. The identified inadequate shields are: the processing hotcells, the target store room and the hotcells in the radiopharmaceutical dispensing laboratory, Point-Kernel radiation shielding calculations are done to specify materials and material thickness that will adequately protect workers against ionising radiation. / Thesis (MSc. ARST) North-West University, Mafikeng Campus, 2004

Thesis (DTech (Electrical Engineering))--Cape Peninsula University of Technology, 2016. / The widespread application of nuclear science and technology has been the subject of much concern as well as nuclear safety issues. And to ensure the safety of public life, property and environment, it is indispensable to improve the emergency system for nuclear accidents and the environmental monitoring system for nuclear radiation, so that the occurrence of nuclear accidents, terrorist incidents and the resulting hazards can be prevented or minimized. Due to the benefits of radiation which were earlier and now recognized in the use of X-rays for medical diagnosis and then later with the discoveries of radiation and radioactivity, there was rush in exploiting the medical benefits which eventually led fairly to the recognition of the risks and induced harm associated with it. Thus, only the most obvious harms resulting from high doses of radiation, such as radiation burns, were initially observed and protection efforts were focused on their prevention, mainly for practitioners rather than patients. Subsequently, it was gradually recognized that there were other, less obvious, harmful radiation effects such as radiation-induced cancer, for which there is certain risk even at low doses of radiation.