Forty years of durability assessment of nuclear waste glass by standard methods

Standard methods to assess the durability of vitrified radioactive waste were first developed in the 1980’s and, over the last 40 years, have evolved to yield a range of responses depending on experimental conditions and glass composition. Mechanistic understanding of glass dissolution has progressed in parallel, enhancing our interpretation of the data acquired. With the implementation of subsurface disposal for vitrified radioactive waste drawing closer, it is timely to review the available standard methodologies and reflect upon their relative advantages, limitations, and how the data obtained can be interpreted to support the post-closure safety case for radioactive waste disposal.

A simulation study of drone delivery of Automated External Defibrillator (AED) in Out of Hospital Cardiac Arrest (OHCA) in the UK

Background Drones are increasingly used in healthcare, and feasibility studies of deployment of Automated External Defibrillators (AED) in Out-of-hospital cardiac arrest (OHCA) have been conducted. Despite the potential contribution of drones to healthcare, regulatory barriers exist, including limits on flights beyond visual line-of-sight (BVLOS). The aim of this project was to deliver an AED BVLOS in Wales. Methods We developed of a Concept of Operations (CONOPS) to identify requirements, constraints, organisation and roles and responsibilities associated with deploying a drone to deliver an AED BVLOS. We equipped a Penguin B drone with satellite-enabled technology to enhance situational awareness and safety for the remote pilot. A BVLOS Operating Safety Case and three-week flight test programme was conducted with an AED attached directly to parachute for deployment to simulated OHCA. Results We completed six flights totalling 92km, 1:02.5 hours of flight time and four successful parachute payload drops. We conducted a successful end-to-end flight demonstration of an AED delivered via BVLOS by drone to a simulated OHCA and resuscitation by lay responder’s in a remote location; the final delivery of 4.5km was completed in 2:50 minutes. Conclusion We have delivered an AED by parachute, from fixed wing drone BVLOS in the UK in simulated OHCA. This project adds to the body of knowledge required for regulatory assurance on drone use BVLOS. Further research is needed before routine use of this technology.

A tentative useful-for-all definition of “safety” in the context of radioactive waste disposal

Most, if not all, national programmes for radioactive waste management pledge their overall commitment to safety or – in the case of radioactive waste disposal – to long-term safety. Therefore, it may be somewhat surprising to find that the term “safety” is hardly defined in these programs. The same holds for some of the core international guidance literature on the deep geological repository (DGR) “safety case” concept. With respect to stakeholder concern over the safety of geological disposal, it seems, however, advisable to seek common ground in the understanding of the idea of “safety”. Hotzel and Schröder (2018) reviewed the most relevant international guidance literature for explicitly or implicitly provided definitions of “safety” in the context of radioactive waste disposal. Based on this study – and on the finding that a practical, useful-for-all definition of “safety” is not provided in the scanned literature – they developed a tentative dictionary-style definition of “safety” that is suitable for everyday use in the DGR context. In the current contribution I embed, expand and update the 2018 study at both ends: As an enhanced introduction to the 2018 study, I lay out a basic concept of “sound” glossary definitions, namely glossary definitions being both practical and correct (and what this means). The thesis is that sound glossary definitions can facilitate mutual understanding between different stakeholder groups. As an update to the actual proposal for the definition of “safety” from the Hotzel and Schröder (2018) paper, that was presented and discussed at the Waste Management Conference 2018, I review the latest international guidance literature and the stakeholder concerns raised at the 2018 conference in order to present a revised definition. As a seed of discussion, it may help to eventually expose possible mismatches in the base assumptions of safety experts and other stakeholders and thereby support meaningful communication.

Transdisciplinary research on repository safety: challenges and opportunities

Since 2019, transdisciplinary research on the scientifically challenging and often controversially debated topic of nuclear waste management on a larger scale has been carried out for the first time in Germany within the co-operative project “TRANSENS” (http://www.transens.de, last access: 21 October 2021). While various and sometimes diverging definitions and understandings of the term “transdisciplinarity” can be found in the literature (e.g., Klein, 2013), we understand it as a specific type of “problem-orientated” basic research integrating a variety of knowledge bodies, values and expectations coming not only from academia but also from the dialogue with society. We consider transdisciplinarity a reflexive, integrative, methodology-guided scientific principle directed at the solution of a societal problem and related scientific challenges by involving non-specialists and actors from practise. Obviously, the safety of nuclear waste management and particularly of waste disposal is an important concern of stakeholders. For specialists, the Safety Case is an established and well-developed instrument supporting safety-informed decisions in a stepwise disposal programme (OECD/NEA, 2013). The idea of Sicherheitsuntersuchungen (safety evaluations) informing decisions in the German siting process is based on the Safety Case concept. However, different stakeholders and interested persons have different notions and views about safety and different values behind these notions (Röhlig and Eckhardt, 2017). The idea behind the TRANSENS Working Package SAFE is to elicit such views and, if possible, to derive conclusions on optimisation potential for the Safety Case. Specifics and potential challenges of this research and ways to address them include: While transdisciplinary research in many cases involves directly affected individuals and groups, TRANSENS is an application-orientated basic research project which does not aim at interfering with the site selection procedure in Germany. Therefore, our research partners from civil society include permanent groups of interested individuals – but not of stakeholders – recruited in a well-defined process. Transdisciplinary research often starts by performing “co-design”, i.e. by jointly formulating the research question(s), but project “funding logic” requires problem definitions already in the application phase of a project. We attempt to overcome this by working in “theme corridors”, which define overarching research questions but leave leeway for later adjustment within these corridors. Being a complex concept, the Safety Case as such might not be well amenable to non-specialists. We address the problem by (i) taking a stepwise approach starting with a preparatory focus group format involving individuals with “Safety Case experience”; (ii) aiming at continuous involvement of one of the permanent groups mentioned above, allowing focussed and in-depth discussions; (iii) being flexible concerning additional transdisciplinary formats and partnerships. The SAFE Working Package team has successfully completed the focus group format under pandemic conditions and is currently preparing the next steps. Preliminary findings include those related to the tool “Safety Case”, to the feasibility of the focus group format in a transdisciplinary context, to observations concerning social interactions within the focus group, and to the way forward. The SAFE team sees opportunities particularly in discussing aspiration and philosophy of safety demonstration, in reflecting potential disciplinary biases influencing both production and criticism of the Safety Case, and for developing new concepts for the interplay between civil society and experts on this complex and elaborated analytical tools in various transdisciplinary formats.

Michigan International Copper Analogue (MICA) project – current status

One of the key requirements for the deep geological disposal of high-level nuclear waste is the assessment of its long-term performance and safety (up to 1 Ma). Regarding engineered barrier system materials, such as copper, much of the data available comes from short-term investigations, such as laboratory experiments at different scales. Copper is an important part of many waste packaging and disposal concepts, e.g. KBS-3 developed in Sweden and Finland and Mark II developed in Canada. Natural analogues provide another important way of obtaining understanding on potential repository system behavior. Observations made from the geological systems can be utilized in the safety case, providing information on the assessment time scale. Copper analogue studies (both natural analogues and archaeological analogues) have been reported in the literature and they have been extensively reviewed by various authors (e.g. Miller et al., 2000) and by safety case projects (e.g. Reijonen et al., 2015) within waste management organizations. So far, only a few studies have focussed on the general stability of native copper within its natural media (e.g. Milodowski et al., 2000; Marcos, 2002). Keweenaw native copper occurrences (Lake Superior, USA) have been mentioned as a qualitative source of information (e.g. in Miller et al., 2000); however, data to be used in process-based safety assessments for geological disposal are lacking. These deposits have been mined for a long time and there is a great deal of knowledge related to them as well as samples collected, but no formal review has been made from the geological disposal point of view. The native copper at the Keweenaw area reflects various geological environments from bedrock to sediment and even anthropogenic mine site remnants and geochemical environments (e.g., anoxic vs. oxic, sulphur-free vs. sulphur-bearing). It thus provides a unique complementary data source that will be useful for estimating processes governing behavior of metallic copper. The MICA project phase I systematically collects and reviews the existing literature and data on the Michigan copper analogue sites and available sampling potential. Here, we present the current status of the project.

Application of Dynamic Risk Approach to Mitigate Major Accidents

Major industrial accidents with catastrophic consequences routinely occur around the world and as the industry continue to grow, so will the system complexities and uncertainties. Hence, the need for a more dynamic approach to hazards identification and risk management, to proactively mitigate potential exposures in a real-time manner. Evidences suggests that, dynamic approach to risk management is capable to identifying and assessing developing and increasing industry risks and processes. The Piper Alpha investigation and derivation and adoption of safety case framework in the UK, was a proven approach to mitigate Major Accident Hazards on the front-end design of high-risk process facilities and through their lifespan. With increasing process systems complexities however, dynamic risk management an enhanced conventional method would be the next generation approach to ensure safer operations. This paper aims to stimulate discussions on the novel Dynamic Risk Management (DRM) approach, leveraging on advanced technologies such as Artificial Intelligence (AI) and the 4th Industrial Revolution (4IR) as a new risk management pathway to industrial accident prevention.

Successful First Implementation of MPD Technology Offshore Australia: Regulatory, Technical and Operational Lessons Learned

This paper details the successful first implementation of closed-loop Managed Pressure Drilling (MPD) technology offshore Australia, on a 6th generation semi-submersible rig. The paper covers the process of achieving safety case acceptance to implement MPD technology from the National Offshore Petroleum Safety and Environmental Management Authority (NOPSEMA), the government regulatory authority. The paper describes the project concept design phase, including a Drill Well on Simulator (DWOS) exercise, which was completed to confirm MPD techniques would mitigate problems experienced on conventionally drilled offset wells. The MPD risk assessments completed included HAZID / BOWTIE / HAZOP / FEA studies which were included in the safety case formal safety assessment that was submitted to NOPSEMA. In parallel the Well Operations Management Plan was submitted, detailing the planned MPD methodology. The detailed Well Engineering scope including the MPD Programme, Operational and Contingency Procedures and Commissioning Process was developed to form a Joint Operations Manual. Four levels of project specific MPD training were developed, reviewed, accepted and monitored by NOPSEMA, including classroom based and rig site practical training. Post MPD system installation in Singapore, the System Integrity Testing was successfully completed offshore Australia. Lastly the paper details MPD operations on the first well including the effective use of MPD well control, dynamic MPD FIT, LOT and Pore Pressure testing and establishing the high formation temperature effects on drilling mud density. The closed-loop MPD system allowed the riser deployed sections to be drilled using a statically underbalanced mud system and confirmed the improved capability and flexibility in terms of detection and controllability during mud loss events.

Successful Conduction of Mid-Humeral Fracture Surgery Under Ultrasound- Guided Supraclavicular Block an a Case of Cervical Scoliosis with Fixed Contracture Deformity Neck and Multiple Comorbidities

Introduction: Regional anaesthesia has been proven lifesaver in many tough anaesthetic situations that demand good operative conditions yet are prone to put the patient under increased risk of post-operative complications including prolonged ICU stays even increasing overall mortality when general anaesthesia is chosen as primary anaesthesia modality. Use of ultrasound has revolutionised our approach to regional anaesthesia and many cases which would otherwise be deemed unfit for usual anatomy based approaches can now be conducted with enhanced precision and safety. Case presentation: We present on such case in a 69-year-old male patient with multiple high-risk factors that precluded safe conduction of general anaesthesia, with the presence of cervical scoliosis with fixed contracture neck making anatomy impossible for a blind approach to brachial plexus. Even with help of ultrasound interscalene level was not accessible due to contracture. The successful supraclavicular block was made possible as we could make a clear distinction between vessels, pleura and rib at that level although the cords appeared haphazardly placed and stretched not conforming to usual anatomy at the level. Conclusion: This case highlights the importance of regional anaesthesia under ultrasound guidance in such complex high-risk cases. As the experience with ultrasound-guided regional anaesthesia continues to grow internationally, we are on our steep learning curve appreciating the benefits and respecting the limitations of this developing technology.