Introduction Transmission of SARS-CoV-2 through aerosol has been suggested, particularly in the presence of highly concentrated aerosols in enclosed environments. It is accepted that aerosols are produced during a range of dental procedures, posing potential risks to both dental practitioners and patients. There has been little agreement concerning aerosol transmission associated with orthodontics and associated mitigation.Methods Orthodontic procedures were simulated in a closed side-surgery using a dental manikin on an acrylic model using composite-based adhesive. Adhesive removal representing debonding was undertaken using a 1:1 contra-angle handpiece (W&H Synea Vision WK-56 LT, Bürmoos, Austria) and fast handpiece with variation in air and water flow. The removal of acid etch was also simulated with the use of combined 3-in-1 air-water syringe. An optical particle sizer (OPS 3330, TSI Inc., Minnesota, USA) and a portable scanning mobility particle sizer (NanoScan SMPS Nanoparticle Sizer 3910, TSI Inc., Minnesota, USA) were both used to assess particulate matter ranging in dimension from 0.08 to 10 μm.Results Standard debonding procedure (involving air but no water) was associated with clear increase in the 'very small' and 'small' (0.26-0.9 μm) particles but only for a short period. Debonding procedures without supplementary air coolant appeared to produce similar levels of aerosol to standard debonding. Debonding in association with water tended to produce large increases in aerosol levels, producing particles of all sizes throughout the experiment. The use of water and a fast handpiece led to the most significant increase in particles. Combined use of the 3-in-1 air-water syringe did not result in any detectable increase in the aerosol levels.Conclusions Particulate matter was released during orthodontic debonding, although the concentration and volume was markedly less than that associated with the use of a fast handpiece. No increase in particulates was associated with prolonged use of a 3-in-1 air-water syringe. Particulate levels reduced to baseline levels over a short period (approximately five minutes). Further research within alternative, open environments and without air exchange systems is required.

This paper presents a new methodology called Waste And Source-matter ANalyses (WASAN) which helps a group to analyse waste-production and build actions to minimise avoidable waste. Designed for Licencees of nuclear facilities as Health and Safety Executive (HSE) Guidance on what constitutes good practice, WASAN uses lessons from Systems Thinking, Waste Management Hierarchy, Hazard Operability (HAZOP) Studies, As Low As Reasonably Practicable (ALARP), simulation modelling and sensitivity analysis. These lessons are used to support groups when developing plans to reduce avoidable waste production. We report on the development of WASAN and its use in three workshops. This paper reports progress on the development of waste management guidance for the HSE and does not currently represent its final regulatory view.

Purpose – The international nuclear community continues to face the challenge of managing both the legacy waste and the new wastes that emerge from ongoing energy production. The UK is in the early stages of proposing a new convention for its nuclear industry, that is: waste minimisation through closely managing the radioactive source which creates the waste. This paper proposes a new technique (called waste and source material operability study (WASOP)) to qualitatively analyse a complex, waste-producing system to minimise avoidable waste and thus increase the protection to the public and the environment. Design/methodology/approach – WASOP critically considers the systemic impact of up and downstream facilities on the minimisation of nuclear waste in a facility. Based on the principles of HAZOP, the technique structures managers' thinking on the impact of mal-operations in interlinking facilities in order to identify preventative actions to reduce the impact on waste production of those mal-operations.' Findings – WASOP was tested with a small group of experienced nuclear regulators and was found to support their qualitative examination of waste minimisation and help them to work towards developing a plan of action. Originality/value – Given the newness of this convention, the wider methodology in which WASOP sits is still in development. However, this paper communicates the latest thinking from nuclear regulators on decision-making methodology for supporting waste minimisation and is hoped to form part of future regulatory guidance. WASOP is believed to have widespread potential application to the minimisation of many other forms of waste, including that from other energy sectors and household/general waste.

The UK has a significant nuclear legacy arising from Government funded work going back to the 1940s. Government is proposing radical changes to current arrangements to tackle this legacy, clean-up nuclear sites and develop its policy for managing solid radioactive waste. As part of these developments the Nuclear Installations Inspectorate of the Health & Safety Executive, the Scottish Environment Protection Agency and the Environment Agency are putting in place joint working arrangements to improve the regulation of intermediate level radioactive wastes (ILW). The aim is to ensure that ILW is managed in a sustainable way taking into account long-term environmental considerations. These arrangements provide for improved regulatory oversight of (i) proposals from nuclear site licensees to condition ILW, and (ii) the work by Nirex to develop further its phased disposal concept (PDC). The regulators will scrutinise: • ILW conditioning proposals: This involves assessing site waste management plans, waste management options (e.g. BPEO assessments), conceptual designs and functional specifications for waste conditioning plants, detailed designs, construction, commissioning and operation of the plants, and the state of waste packages. • Nirex’s on-going work: This involves examining Nirex’s PDC, its application to ILW conditioning proposals and associated Letters of Comfort/Letters of Advice (LoC/LoA) and the possible future development of an environmental safety case for an eventual repository. A description is given of the regulators’ process associated with these new arrangements.