Performance of a DrumScan® HRGS Solo Scanner for the Assay of Legacy Waste at the Belgoprocess Site

Author(s):  
Daniel F. Parvin ◽  
Thomas Huys

On the sites of Belgoprocess several thousands of drums containing conditioned legacy waste are stored. A significant number of these waste packages are 220 litre drums containing radioactive waste embedded into inactive bitumen. Most of the radioactive waste in these drums was generated during the development and production of MOX-fuels and the operation of the Eurochemic reprocessing plant. The current state of a number of these packages is no longer acceptable for long term storage. In order to make the waste packages acceptable for interim storage a repackaging process was developed. The process involves the repackaging of the waste items into 400 or 700 litre waste drums and a non-destructive gamma-ray assay (NDA) measurement performed on the new package. The aim of the NDA measurement is to detect significant quantities of fissile material in order to demonstrate compliance with the operational limits of the storage building. Since the waste items are destined for geological disposal, there is no specific need for a detection limit in the order of milligrams of plutonium as required for surface disposal. To meet this NDA requirement Babcock International Group supplied, calibrated and commissioned an open geometry system from its HRGS product range. The DrumScan® HRGS Solo assay system was delivered to the Belgoprocess site in 2009 after completing a series of factory acceptance tests performed in the UK. In May 2009 after successful completion of the site acceptance tests performed in Belgium, the system has been undergoing extensive testing and validation by Belgoprocess in order to demonstrate acceptance and compliance to the Belgian Radioactive Waste Agency, NIRAS/ONDRAF. After a careful evaluation of the qualification file, NIRAS/ONDRAF approved the system for operational measurements at the end of 2010. This paper provides a detailed description of the NDA requirement, calibration methodology, system validation tests and overall measurement performance of the system.

Author(s):  
Jenny Morris ◽  
Stephen Wickham ◽  
Phil Richardson ◽  
Colin Rhodes ◽  
Mike Newland

The UK Nuclear Decommissioning Authority (NDA) is responsible for safe and secure management of spent nuclear fuel. Magnox spent fuel is held at some Magnox reactor sites and at Sellafield where it is reprocessed using a number of facilities. It is intended that all Magnox fuel will be reprocessed, as described in the published Magnox Operating Plan (MOP) [1]. In the event, however, that a failure occurs within the reprocessing plant, the NDA has initiated a programme of activities to explore alternative contingency options for the management of wetted Magnox spent fuel. Magnox fuel comprises metallic uranium bar clad in a magnesium alloy, both of which corrode if exposed to oxygen or water. Consequently, contingency options are required to consider how best to manage the issues associated with the reactivity of the metals. Questions of whether Magnox spent fuel needs to be dried, how it might be conditioned, how it might be packaged, and held in temporary storage until a disposal facility becomes available, all require attention. A review of potential contingency options for Magnox fuel was conducted by Galson Sciences Ltd, UKAEA and the NDA. During storage in the presence of water, the corrosion of Magnox fuel produces hydrogen (H2) gas, which requires careful management. When uranium reacts with hydrogen in a reducing environment, the formation of uranium hydride (UH3) may occur, which under some circumstances can be pyrophoric, and might create hazards which may affect subsequent retrieval and/or repackaging (e.g. for disposal). Other factors that may affect the choice of a viable contingency option include criticality safety, environmental impacts, security and Safeguards and economic considerations. At post-irradiation examination (PIE) facilities in the UK, Magnox spent fuel is dried as a result of storage in air at ambient temperatures. Early French UNGG (Uranium Naturel Graphite Gaz) fuel was retrieved from pond storage at Cadarache, dried using a hot gas drying technique, oxidised and packaged in sealed canisters and placed in interim storage at the CASCAD (CASemate CADarache) facility. In the US, spent fuels including the Zircaloy clad Hanford N-Reactor fuels were cold vacuum dried and Idaho legacy aluminium clad metallic uranium fuels were hot vacuum dried; the dried fuel was then packaged in sealed and vented canisters (at Hanford and Idaho, respectively) for interim storage. With regard to conditioning and packaging, several different approaches have been reviewed, including encapsulation in cementitious grout or polymer, high-temperature vitrification or ceramicisation, and solution in acid or alkali solution followed by cementation or vitrification (without reprocessing). All of these approaches require further research in order to be evaluated and developed further for application to formerly wetted Magnox fuel. A variety of containers have been developed for the transport, storage and/or disposal of spent fuel in radioactive waste management programmes worldwide. Wetted Magnox spent fuel could be packaged in a container, with reservations about the potential formation of UH3 in a sealed environment where reducing conditions may develop. The applicability of different combinations of drying, conditioning and packaging techniques to the preparation of Magnox spent fuel for long-term storage and eventual disposal are discussed.


2021 ◽  
Vol 253 ◽  
pp. 08002
Author(s):  
Paolo Finocchiaro ◽  
Luigi Cosentino ◽  
Quentin Ducasse ◽  
Sergio Lo Meo ◽  
Fabio Longhitano ◽  
...  

In the framework of the MICADO (Measurement and Instrumentation for Cleaning And Decommissioning Operations) European Union (EU) project, aimed at the full digitization of low and intermediate-level radioactive waste (radwaste) management, a set of 32 solid state thermal neutron detectors, named SiLiF, and 36 gamma-ray counters based on a scintillating fiber readout at each end by a silicon photomultiplier, named SciFi, have been built and characterized. MICADO project encompasses a complete active and passive characterization of the radwaste drums with neutrons and gamma rays, followed by a longer-term monitoring phase. The detectors described are suitable for the monitoring of nuclear materials and can be used around radioactive waste drums possibly containing small quantities of actinides, as well as around spent fuel casks in interim storage or during transportation. Suitable polyethylene moderators, for the SiLiF detectors, can be exploited to better shape the detector response to the expected neutron spectrum, according to Monte Carlo simulations that were performed. The SciFi detectors were thoroughly tested with a 22Na and a 137Cs gamma-ray sources. Both detectors described were tested with an intense AmBe source of neutron and gamma ray. The results are satisfactory and show a quite uniform and reproducible behavior. The next step will be the test in a real environment.


Author(s):  
Chris Perriam ◽  
Darren Waldron

This book advances the current state of film audience research and of our knowledge of sexuality in transnational contexts, by analysing how French LGBTQ films are seen in Spain and Spanish ones in France, as well as how these films are seen in the UK. It studies films from various genres and examines their reception across four languages (Spanish, French, Catalan, English) and engages with participants across a range of digital and physical audience locations. A focus on LGBTQ festivals and on issues relating to LGBTQ experience in both countries allows for the consideration of issues such as ageing, sense of community and isolation, affiliation and investment, and the representation of issues affecting trans people. The book examines films that chronicle the local, national and sub-national identities while also addressing foreign audiences. It draws on a large sample of individual responses through post-screening questionnaires and focus groups as well as on the work of professional film critics and on-line commentators.


2019 ◽  
Vol 26 (6) ◽  
pp. 319-324
Author(s):  
Victor K. Uteshev ◽  
Edith N. Gakhova ◽  
Ludmila I. Kramarova ◽  
Natalia V. Shishova ◽  
Svetlana A. Kaurova ◽  
...  

In modern biology, a search for efficient and safe ways of long-term storage of animal genomes is vital for the survival of rare and endangered species. To date, the only reliable method of prolonging the preservation of genome is deep freezing of somatic and reproductive cells, including spermatozoa. Here we overview the current state of reproductive technologies and present the cryopresevation strategies of genetic material of selected amphibian species. These strategies were developed at the Institute of Cell Biophysics, Russian Academy of Sciences, Pushchino, Russia. Cryopreservation could help managing the threatened populations of amphibian species through genome storage and mediate the production of healthy animals from the stored material.


Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2630
Author(s):  
Luigi Cosentino ◽  
Quentin Ducasse ◽  
Martina Giuffrida ◽  
Sergio Lo Meo ◽  
Fabio Longhitano ◽  
...  

In the framework of the MICADO (Measurement and Instrumentation for Cleaning And Decommissioning Operations) European Union (EU) project, aimed at the full digitization of low- and intermediate-level radioactive waste management, a set of 32 solid state thermal neutron detectors named SiLiF has been built and characterized. MICADO encompasses a complete active and passive characterization of the radwaste drums with neutrons and gamma rays, followed by a longer-term monitoring phase. The SiLiF detectors are suitable for the monitoring of nuclear materials and can be used around radioactive waste drums possibly containing small quantities of actinides, as well as around spent fuel casks in interim storage or during transportation. Suitable polyethylene moderators can be exploited to better shape the detector response to the expected neutron spectrum, according to Monte Carlo simulations that were performed. These detectors were extensively tested with an AmBe neutron source, and the results show a quite uniform and reproducible behavior.


Author(s):  
T. W. Turner ◽  
S. N. Watson

The solid waste plant at Harwell in Oxfordshire, contains a purpose built facility to input, assay, visually inspect and sort remote handled intermediate level radioactive waste (RHILW). The facility includes a suite of remote handling cells, known as the head-end cells (HEC), which waste must pass through in order to be repackaged. Some newly created waste from decommissioning works on site passes through the cells, but the vast majority of waste for processing is historical waste, stored in below ground tube stores. Existing containers are not suitable for long term storage, many are already badly corroded, so the waste must be efficiently processed and repackaged in order to achieve passive safety. The Harwell site is currently being decommissioned and the land is being restored. The site is being progressively delicensed, and redeveloped as a business park, which can only be completed when all the nuclear liabilities have been removed. The recovery and processing of old waste in the solid waste plant is a key project linked to delicensing of a section of the site. Increasing the operational efficiency of the waste processing plant could shorten the time needed to clear the site and has the potential to save money for the Nuclear Decommissioning Authority (NDA). The waste processing facility was constructed in the mid 1990s, and commissioned in 1999. Since operations began, the yearly throughput of the cells has increased significantly every year. To achieve targets set out in the lifetime plan (LTP) for the site, throughput must continue to increase. The operations department has measured the overall equipment effectiveness (OEE) of the process for the last few years, and has used continuous improvement techniques to decrease the average cycle time. Philosophies from operational management practices such as ‘lean’ and ‘kaizen’ have been employed successfully to drive out losses and increase plant efficiency. This paper will describe how the solid waste plant at Harwell has continuously increased the throughput of RHILW, which should lead to significant programme savings.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
M. B. Maina ◽  
U. Ahmad ◽  
H. A. Ibrahim ◽  
S. K. Hamidu ◽  
F. E. Nasr ◽  
...  

AbstractNeuroscience research in Africa remains sparse. Devising new policies to boost Africa’s neuroscience landscape is imperative, but these must be based on accurate data on research outputs which is largely lacking. Such data must reflect the heterogeneity of research environments across the continent’s 54 countries. Here, we analyse neuroscience publications affiliated with African institutions between 1996 and 2017. Of 12,326 PubMed indexed publications, 5,219 show clear evidence that the work was performed in Africa and led by African-based researchers - on average ~5 per country and year. From here, we extract information on journals and citations, funding, international coauthorships and techniques used. For reference, we also extract the same metrics from 220 randomly selected publications each from the UK, USA, Australia, Japan and Brazil. Our dataset provides insights into the current state of African neuroscience research in a global context.


2018 ◽  
Vol 21 (18) ◽  
pp. 3360-3376 ◽  
Author(s):  
Stephanie B Jilcott Pitts ◽  
Shu Wen Ng ◽  
Jonathan L Blitstein ◽  
Alison Gustafson ◽  
Mihai Niculescu

AbstractObjectives(i) To determine the current state of online grocery shopping, including individuals’ motivations for shopping for groceries online and types of foods purchased; and (ii) to identify the potential promise and pitfalls that online grocery shopping may offer in relation to food and beverage purchases.DesignPubMed, ABI/INFORM and Google Scholar were searched to identify published research.SettingTo be included, studies must have been published between 2007 and 2017 in English, based in the USA or Europe (including the UK), and focused on: (i) motivations for online grocery shopping; (ii) the cognitive/psychosocial domain; and (iii) the community or neighbourhood food environment domain.SubjectsOur search yielded twenty-four relevant papers.ResultsFindings indicate that online grocery shopping can be a double-edged sword. While it has the potential to increase healthy choices via reduced unhealthy impulse purchases, nutrition labelling strategies, and as a method to overcome food access limitations among individuals with limited access to a brick-and-mortar store, it also has the potential to increase unhealthy choices due to reasons such as consumers’ hesitance to purchase fresh produce online.ConclusionsAdditional research is needed to determine the most effective ways to positively engage customers to use online grocery shopping to make healthier choices.


Author(s):  
Jenny Morris ◽  
Stephen Wickham ◽  
David Nicholls ◽  
Ciara Walsh ◽  
James McKinney

The NDA’s Upstream Optioneering project has examined the potential implications of using an alternative type of waste package and its influence on the waste management lifecycle across the NDA estate. Robust Shielded Containers (RSCs) are radioactive waste packages that provide integral radiological shielding, reducing the need for remote handling. The robustness of the container could remove the need to immobilise waste by cement encapsulation. RSCs are routinely used to package ILW for interim storage in Germany and have fairly recently been considered for use in the UK because RSCs have the potential to simplify the waste management lifecycle and enable risk and hazard reduction. In particular, the current baseline (included in Magnox Limited lifetime plans) follows the strategy set out in the Magnox Operating Decommissioning Programme (MODP), in which Type II MOSAIK and Type VI Ductile Cast Iron Containers (DCICs) are used to package (in non-encapsulated form) most Magnox ILW arising prior to 2050. By considering representative types of Intermediate Level Waste (ILW) and exploring potential packaging options for these wastes, this paper identifies the factors that could differentiate between cases in which RSCs would, or would not, be an appropriate option. The potential role of RSCs across the waste management lifecycle is examined, from retrieval of waste through to emplacement at a Geological Disposal Facility (GDF), including consideration of other potential uses of RSCs, such as temporary storage of raw wastes for which appropriate treatment and conditioning measures have yet to be developed.


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