Surface degradation of laminated metal226Ra foils used in school sealed sources in the UK.

In the few years leading up to this research, CLEAPSS noticed a small but steadily increasing number of calls from UK schools regarding a red-brown discolouration on the surface of the foil of their radium source. There were no reports of this type of discolouration on foils of other radionuclides. CLEAPSS and the University of Liverpool collaborated to investigate the nature and cause of this discolouration and the likelihood that the foils were becoming unsafe. The evidence indicates that the discolouration is principally caused by some combination of silicon, sulfur and possibly lead from within the foil diffusing into the face layer. There is no indication currently that the face layers are fragmenting on these foils, but the longer-term integrity of the discoloured foils now becomes questionable. Given the age of the foils and the radiotoxicity of radium, the recommendation from this research is that discoloured foils should be taken out of service and disposed.

The status of the radiation safety culture within the higher education, research and teaching sectors in the UK.

This article reports on the research by a working group, comprising members from the Association of University Radiation Protection Officers, on the radiation safety culture in the UK higher education, research and teaching (HERT) sectors. The impetus for this research arises from the work of the International Radiation Protection Association and their emphasis that embedding radiation safety culture within an organisation is the most effective way of delivering the standards of radiation safety and security that society expects. The deficiency in radiation safety culture has been a large contributor to major nuclear disasters, such as Chernobyl and Fukushima Daiichi. The working group designed an online survey aimed at higher education students, higher education academics, and researchers. The survey did not try to obtain an indication of safety performance, but of people's views on behaviours and attitudes of radiation safety that reflect the current radiation safety culture in their organisation. The findings of the survey are reported in this article along with a discussion of the analysis and recommendations for improving radiation safety culture. The responses from the survey strongly indicate that the radiation safety culture in UK HERT sectors has worrying shortfalls, particularly in communication and training.

The advantages of creating a positive radiation safety culture in the higher education and research sectors.

The safety culture of any organisation plays a critical role in setting the tone for both effective delivery of service and high standards of performance. By embedding safety at a cultural level, organisations are able to influence the attitudes and behaviours of stakeholders. To achieve this requires the ongoing commitment of heads of organisations and also individuals to prioritise safety no less than other competing goals (e.g. in universities, recruitment and retention are key) to ensure the protection of both people and the environment. The concept of culture is the same whatever the sector, e.g. medical, nuclear, industry, education, and research, but the higher education and research sectors within the UK are a unique challenge in developing a strong safety culture. This report provides an overview of the challenges presented by the sector, the current status of radiation protection culture, case studies to demonstrate good and bad practice in the sector and the practical methods to influence change.

Strategies for engaging with future radiation protection professionals: a public outreach case study.

It is evident that there is a nuclear skills shortage within the UK, and logically it can be assumed that the shortfall extends to the radiation protection arena. Plans for nuclear new-build and the decommissioning of existing nuclear sites will require many more people with radiological knowledge and practical competencies. This converts to a nuclear industry requirement in the order of 1000 new recruits per year over at least the next ten years, mainly as new apprentices and graduates. At the same time, the strong demand for persons with radiation protection know-how in the non-nuclear and health care sectors is unlikely to diminish. The task of filling this skills gap is a significant one and it will require a determined effort from many UK stakeholders. The Society for Radiological Protection (SRP) has adopted a strategy in recent years to help address this skills gap. The aim is to engage the interest of secondary school students in the science of radiation and inspire them to follow a career in radiation protection. This paper presents the reasoning behind this strategy and, in an 'outreach case study', describes the establishment of the annual SRP Schools Event. This event is becoming an important addition to the national efforts aimed at increasing the numbers of skilled UK radiation protection professionals over the forthcoming decades.

Evidence for age-related performance degradation of (241)Am foil sources commonly used in UK schools.

The characteristics of alpha radiation have for decades been demonstrated in UK schools using small sealed (241)Am sources. There is a small but steady number of schools who report a considerable reduction in the alpha count rate detected by an end-window GM detector compared with when the source was new. This cannot be explained by incorrect apparatus or set-up, foil surface contamination, or degradation of the GM detector. The University of Liverpool and CLEAPSS collaborated to research the cause of this performance degradation. The aim was to find what was causing the performance degradation and the ramifications for both the useful and safe service life of the sources. The research shows that these foil sources have greater energy straggling with a corresponding reduction in spectral peak energy. A likely cause for this increase in straggling is a significant diffusion of the metals over time. There was no evidence to suggest the foils have become unsafe, but precautionary checks should be made on old sources.

The use of a Monte Carlo method to calculate the average solid angle subtended by a detector to source in a non-parallel plane.

In a previous scientific note, a short computer program for a personal computer was described that calculated the average solid angle subtended by a circular or rectangular detector window to a circular or rectangular source in a parallel plane by a Monte Carlo method. This note describes the development of the program for conditions where the detector window is not parallel to the plane of the source, and in particular looks at a method of analysing orientations that relates straightforwardly to practical measurement.

Calculation of the average solid angle subtended by a detector to source in a parallel plane by a Monte Carlo method.

A short computer program is described for a PC which uses a Monte Carlo method to calculate the average solid angle subtended by a rectangular or circular detector window to a coaxial or non-coaxial rectangular, circular or point source. The advantage of the Monte Carlo method is that it allows the calculation of average solid angle for source-detector geometries that are difficult to analyse by analytical methods. The values of solid angle are calculated to accuracies of typically better than 0.1%. The calculated values from the Monte Carlo method agree closely with those produced by polygon approximation and numerical integration by Gardner and Verghese, and others.

Time-resolved beam structure of an active Q-switched ruby laser.

Time-resolved observations show that the near field and far field patterns of an active Q-switched ruby laser remain almost constant for the duration of the output pulse. This is in marked contrast to the reported behavior of a passive Q-switched laser.