Systemic Approach to Failure Analysis: A Study of Sociotechnical Organization

The paper is an attempt to explore systemic approach to accidents analysis within sociotechnical organization. Unsafe behaviors can result in systemic failures and accidents. The research data came from within an industrial radiography organization where radiation source is used to detect cracks or hidden flaws within machinery and welding joints. The radioactive source can cause severe detrimental effects, even death, if not used safely. This paper is on two isolated events happen in the same company, Industrial Services Private Limited (not real name). The company top management was dealing with the financial crisis and to maintain quality of its services and the safety of staff. The leadership of the company made several business and operational decisions to manage the financial crisis. During that time, several near miss incidents took place, but the first major incident took place when the radiography gamma projector, along with the radioactive source, fallen out of the vehicle because of improper back door closure of the vehicle. In the second incident, the radioactive source remained unshielded after a radiography job, this caused overexposure to radiography workers. The paper provides an opportunity to understand how an organization’s leadership can create conditions for errors and mistakes that result in poor safety culture and ultimately the accident which resulted the system failure and operation shutdown. The paper also tries to propose a conceptual framework to improve safety culture within the sociotechnical systems for the future research in this area.

RESEARCH ON THE PROPERTIES OF SORBENTS AND DECONTAMINANTS IN THE PROCESSES WITH SMALL ISOTOPE EFFECTS

The low values of isotope effects in the sorption/decontamination processes make it possible to investigate the properties of the sorbing and decontaminating agents with the use of stable isotope simulators. In the work present-ed here the element content was determined from the characteristic X-ray emission induced by the proton beam (PIXE), by gamma-ray emission from the radioactive source, and by emission from the X-ray tube. Based on the results of efficiency determination for different kinds of sorbents and decontaminants, recommendations have been given for the choice of materials having the wanted performance characteristics.

Reconstructive dosimetry and radiation dose evaluation of workers and public due to a brazilian radiological accident in industrial radiography

Radiological accidents occur mainly in the practices recognized as high risk and which are classified by the IAEA as Categories 1 and 2: radiotherapy, industrial irradiators and industrial radiography. In Brazil, 5 important cases in industrial gamma radiography occurred from 1985 to 2018, involving 7 radiation workers and 19 members of the public. The accidents caused localized radiation lesions on the hands and fingers. One of these accidents is the focus of this paper. In this accident, a 3.28 TBq 192Ir radioactive source was left unshielded for 9 hours in a NDT company parking lot, and many radiation workers, employees and public, including teachers of a primary school were exposed. The radioactive source was also directly handled by a security worker for about 1.5 min causing severe radiation injuries in the hand and fingers. This paper presents radiation dose estimates for all accidentally exposed individuals. Four scenarios were considered, and three internationally recognised and updated reconstructive dosimetry techniques were used, named, Brazilian Visual Monte Carlo Dose Calculation (VMC), Virtual Environment for Radiological and Nuclear Accidents Simulation (AVSAR) and RADPRO Calculator®. The main radiation doses estimated by VMC were the absorbed dose of 34 Gy for the security worker’s finger and his effective dose of 91 mSv; effective doses from 43 to 160 mSv for radiation workers and NDT employees; and effective doses of 9 mSv for teachers in the schoolyard.

Charge sharing investigation in a Timepix3 (TPX3) detector through ion probing

The phenomenon of charge sharing in pixelated particle detectors and its relationship to a variety of physical parameters is investigated using a Timepix3 (TPX3) detector with a 500 μm thick silicon sensor. A probing technique is used with H, Li, and C ion beams produced at the Tandem Van de Graaff (VdG) accelerator at the University of Montreal (UdeM), as well as alpha particles from an 241Am radioactive source, to determine a direct relationship between particle depth and cluster size. Additionally, the primacy of a particle's energy on the determination of its corresponding cluster's size is confirmed.

Measured distribution of cloud chamber tracks from radioactive decay: a new empirical approach to investigating the quantum measurement problem

Using publically available video of a cloud chamber with a very small radioactive source, I measure the spatial distribution of where tracks start, and consider possible implications. This is directly relevant to the quantum measurement problem and its possible resolution, and appears never to have been done before. The raw data are relatively uncontrolled, leading to caveats that should guide future, more tailored experiments. Track distributions from decays in cloud chambers represent a previously unappreciated way to probe the foundations of quantum mechanics, and a novel case of wavefunctions with macroscopic signatures.

Measured distribution of cloud chamber tracks from radioactive decay

Using publically available video of a cloud chamber with a very small radioactive source, I measure the spatial distribution of where tracks start, and consider possible implications. This is directly relevant to the quantum measurement problem and its possible resolution, and appears never to have been done before. The raw data are relatively uncontrolled, leading to caveats that should guide future, more tailored experiments. Track distributions from decays in cloud chambers represent a previously unappreciated way to probe the foundations of quantum mechanics, and a novel case of wavefunctions with macroscopic signatures.

Rapid detection method of radioactive source based on low-count gamma spectra

In order to solve the problem of searching a radioactive source in a wide area, we developed a mobile CsI detector. This paper presented the performance of the detector during the spectra collection investigation. The 1 s spectrum collected by the detector was low-count spectrum and it is hard to distinguish whether it contains radioactive source signals. A rapid detection method of radioactive source based on low-count gamma spectra was proposed. Principal component analysis (PCA) was the key technology of the method. According to the PCA, the source information was efficiently extracted. With the method, the detect sensitivity and accuracy of the detector were optimized.

Rapid detection method of radioactive source based on low-count gamma spectra

In order to solve the problem of searching a radioactive source in a wide area, we developed a mobile CsI detector. This paper presented the performance of the detector during the spectra collection investigation. The 1 s spectrum collected by the detector was low-count spectrum and it is hard to distinguish whether it contains radioactive source signals. A rapid detection method of radioactive source based on low-count gamma spectra was proposed. Principal component analysis (PCA) was the key technology of the method. According to the PCA, the source information was efficiently extracted. With the method, the detect sensitivity and accuracy of the detector were optimized.