This database is an independently verified, regularly maintained and freely available resource that can act as a ‘best practice’ reference tool for use at any stage of the authorisation or permitting cycle. It can assist nuclear organisations to determine the feasible options for legally-required Best Practicable Environmental Option (BPEO), Best Practicable Means (BPM) and Best Available Technique (BAT) studies because it also identifies where each technique is or has been employed across the nuclear industry. In addition the website provides information to encourage users to apply the waste hierarchy (avoid, minimise, reuse, recycle, recover energy, dispose) at the highest practicable level, a fundamental principle of waste management.
In addition, the group that developed the website, the Environment Agencies’ Requirements Working Group (EARWG) is working with waste repository operator Low Level Waste Repository Ltd to develop and enhance the website to support and implement the UK Nuclear Industry Low Level Waste Strategy [1] and the industry’s proposed Management Plan [2].
The website has been incorporated into the Management Plan; it aims to become the national focus in radioactive waste management. Currently, LLW in the UK is consigned to the Low Level Waste Repository (LLWR) near the village of Drigg in west Cumbria. This site is the only dedicated engineered facility for such waste in the UK.
The amount of LLW forecasted to be produced in the UK is much higher than the capacity of the LLWR. Continuing to manage LLW as has been done in the past is not a sustainable practice. Therefore to make best use of the facility it is important that only wastes that require engineered multi-barrier containment are consigned to the site. Where the generation of waste cannot be avoided or the waste has already been generated, the volume and activity of that waste should be minimised. The use, development and promotion of the EARWG website can help with this goal.
Regulatory background
EARWG is a UK industry working group consisting of representatives from 16 nuclear site licensed companies (see Table 1). The group was originally formed in 2002 to provide a collective approach in addressing the generic issues raised within the Radioactive Substances Act certificates of authorisation.
It is a requirement of the Radioactive Substances Act 1993 (RSA 93; now replaced by the Environmental Permitting Regulations 2010 in England and Wales) that operators must hold authorisations to accumulate radioactive material on and dispose of material from their sites. These authorisations are generally reviewed every four years. One authorisation covers all waste media: solid, liquid and gas. The authorisations’ format is common to both the Environment Agency (EA) and the Scottish Environment Protection Agency (SEPA), which include ‘Additional Information and Improvement Requirements’ (AIIRs). Some of these AIIRs are generic and relate to the achievement of best practice across the nuclear industry; others are specific to individual operator activities. The EA and SEPA impose time limits for completion of the AIIRs, compliance with which is mandatory under the 2010 permitting regulations.
Since its formation, EARWG has focused on two generic AIIRs related to waste assay and waste minimisation. In 2004 the Group began a waste assay programme that resulted in the creation of the Waste Assay Attribute Tool (WAAT), a database containing details of assay techniques for radioactive waste streams applied by one or more operator within the UK nuclear industry. A comprehensive review and development programme for WAAT and corresponding database is underway, the aim of which is update the information, improve functionality and share best practice in current waste assay practices across the country.
The majority of the group’s work has focused on the generic waste minimisation requirement. The group has concluded that the ‘national and international review of waste minimisation techniques’ (according to the AIIR) is a common task that could be undertaken jointly.
Website development
In 2003 AREVA RMC began the development of www.rwbestpractice.co.uk to provide a platform for the ‘national and international review of waste minimisation techniques’ on behalf of EARWG. The website hosts a best practice in waste minimisation database (BPWMD) that contains more than 130 data sheets on best practice techniques for waste minimisation of solid, liquid and gaseous radioactive waste, as well as additional information relating to minimisation of controlled (non-active) wastes, re-use and recycling, and radioactive waste assay techniques.
To populate the BPWMD, EARWG performed a systematic trawl for and review of national and international waste minimisation information sources. This included but was not limited to the following:
- nuclear operator technical reports (produced internally or externally by contractor organisations)
- regulatory and advisory bodies
- conferences and proceedings
- books
- journals
- manufacturer technical data sheets
- British standards
For the purposes of the BPWMD, waste minimisation was defined as any process that reduces the activity and/or volume of waste at any stage in the waste management process.
Information in the BPWMD is stored within a data sheet organised in a hierarchical structure that becomes more detailed with each successive tier. Data sheets can be viewed in an online template or as a printable report. They follow a prescribed format. Each data sheet includes information under the following headings:
- process description
- performance characteristics and parameters
- key instrumentation and control
- limitations and constraints on use
- secondary waste arisings
- key management systems
- independent reviewer cv and date of approval
- source/reference list
Each data sheet incorporates an ‘Industry Use of Techniques’ tab that enables users to obtain detailed application statements as to how the technique is or was used, what the technique is or was used for (or on what material), and where and when the technique is or was used. This aspect of the BPWMD enables it to have a far wider application than just responding to the radioactive waste minimisation AIIR. It provides a single point of information for a range of waste minimisation techniques that could be considered when conducting BPEO, BPM and BAT studies.
To maintain a high level of provenance and accuracy in the data provided within the BPWMD, each data sheet enters an extensive programme of internal and independent review and approval prior to publication in the BPWMD. Following the systematic trawl of information and initial drafting of the data sheet a period of specialist internal review occurs. In that process, an experienced senior consultant within AREVA RMC will undertake a review and provide input on the content of the data sheet. The next stage is the independent review process. AREVA RMC has a panel of 10 independent reviewers from national and international organisations. Initially, it sent a ranking spreadsheet to each reviewer to identify his or her knowledge of the technique. This is done to assist allocation of the data sheets to the most suitable reviewer. Once one is found, they are invited to verify the provenance and accuracy of the information and its fitness for inclusion. Most of the technologies are relatively simple and will only be reviewed by one person. One person may be required to review multiple data sheets.
The process description must be sufficiently detailed that a professional engineer unfamiliar with the technique can understand it. It must also describe the substrates (such as concrete, lead, stainless steel, wood, plastics, graphite) on which the technique may be used. The data sheet should also describe the main parameters that determine the choice of the technique, the main plant requirements, the operating limitations of this particular process, including an outline of its disadvantages or advantages, and all resultant wastes.
Following any necessary amendments and final approval from the EARWG, the data sheet can be published in the BPWMD.
The EARWG have made the website and BPWMD freely available. Its members believe that communication with the public through openness and transparency is an essential driver to maintain on-going trust and support of the nuclear industry.
It is vital that the information in the EARWG BPWMD is accurate, relevant and up to date. The EARWG BPWMD is a live document to be used by each operator as they move through their authorisation or permitting cycle. The environmental permitting regulations certificates of authorisation are issued to each operator at different times; therefore the delivery date for each AIIR varies for each operator. In addition, whilst some of the technologies are well developed, others are currently in research and may be used commercially in the near future. New techniques for waste minimisation may also arise and will need to be included in the BPWMD.
A simple methodology was produced to review relevant information sources for new or modified techniques with a view to its inclusion in the BPWMD. Relevant information sources were identified which would be used to undertake such a review and grouped into two categories. Category A sources are reviewed annually and include conferences, manufacturers’ web pages and technical reports. Category B sources are reviewed every two years and include British Standards, scientific journals, regulatory and advisory bodies and books. Any additional, amended or new information is reviewed, and if approved is added to the appropriate data sheets in the BPWMD. In order to avoid duplicating research, a waste minimisation information sources database was compiled.
In 2009 the EARWG BPWMD and website was selected to support the implementation of the UK Nuclear Industry LLW Management Plan, which identifies the scope, schedule, and resources (how, when and who) needed for improving LLW management through the entire waste lifecycle. Sixty potential strategic initiatives have been identified which together provide significant synergies or opportunities to improve LLW management today.
Those initiatives include standardising waste avoidance and minimisation programmes and identifying and sharing waste avoidance and minimisation (and re-use and recycling) best practices.
Therefore, over the past eight months the EARWG and the Drigg repository operator Low Level Waste Repository Ltd have worked together to develop, populate and promote the existing website and support the realisation of two strategic initiatives in particular. This work consisted of four jobs. First, they created and populated a new re-use and recycling web page containing generic information and identification of re-use and recycling guidance documents. Second, they updated key solid radioactive waste minimisation technique data sheets. Third, they undertook a trial identification and collection of re-use and recycling good practices. Fourth, they developed an on-going promotional strategy for the website. The numbers of visitors to the website has steadily grown since its production and an increasing amount of international visits are being seen.
Re-use and recycling of waste as materials from within the nuclear industry have been limited to clean wastes which have not been in any contaminated controlled areas. There are, however, significant opportunities to change the status quo and through effective sentencing and monitoring regimes, allow wastes such as metals and concrete, to be re-used, maximising the recovery of such materials, increasing sustainability, and thereby reducing the costs and environmental impact of using new materials.
The collective implementation of the 60 strategic initiatives identified in The Management Plan could produce a step-change improvement in LLW management practices across the UK and contribute significant savings to the LLW baseline. Implementation of the initiatives has the potential to extend the life of LLWR, and have significant environmental and sustainability benefits over the entire waste lifecycle. The detailed initiatives will also help realise the significant opportunities presented in the proposed UK Nuclear Industry LLW Strategy.
Any comments or suggestions about the website are welcomed by the EARWG members.
Author Info:
George Knight,consultant, AREVA RMC; Sarah Greenwood, assistant director for commercial and business development, AREVA RMC; Andrew Laker, LLW planning manager, Low Level Waste Repository Ltd
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| Table 1: EARWG members |
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AWE Babcock International Group (Marine Division) BAe Systems Marine British Energy Dounreay Site Restoration GE Healthcare LLW Repository Magnox North Magnox South Ministry of Defence Rolls-Royce Marine Power Operations Research Sites Restoration Sellafield Springfields Fuel Studsvik UK URENCO UK |
| Example waste minimisation technique: Use of abrasive cleaning [edited] |
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Process description Performance characteristics and parameters Abrasive blasting is a rapid technique and high Decontamination Factors (DFs) are achievable since the target surface is abraded away. The longer the technique is applied, the higher the DF that can be achieved. The success of the method depends on the standoff distance, the traverse rate and the angle of incidence. The useful life of the abrasive is dictated by two factors; the resilience of the surface being abraded and the grade (sharpness) of the shot itself… Key instrumentation and control Equipment is adaptable for remote automation whether by moving the item between an array of fixed jets or by the use of moveable jets, which traverse the item. Individual items are usually cleaned in an engineered containment to reduce the spread of contamination. Air filters are used to protect the equipment from contamination…The surrounding environment and workers must be protected from potentially contaminated dust by provision of appropriate controls. The main requirements of abrasive systems are the power required to drive the compressors / rotors in order to propel the abrasives; abrasive media; and water, whether for wet blasting or as a water spray for dust suppression activities… Limitations and constraints on use The longer and more penetrating the blasting becomes, the larger the amount of secondary waste generated. For dry abrasive methods, dust must be suppressed by keeping the surface damp during blasting. The application of blasting technologies is generally limited to easy to access surface contaminants. This technique is not suitable for deep or neutron induced radioactivity. Secondary waste arisings Waste arisings consist of the removed substrate (such as paint flakes, rust particles, etc.) and the blast media, the latter of which may be recycled for further use for example cyclone systems can reuse pellets up to thirty times. The main types of media that may be segregated for re-use are durable materials (e.g. shot). Friable or organic material can only be recycled a few times until it becomes too small to be an effective abrasive agent… Key management systems Record keeping: Routine checks should be made on the abrasive operating mix, discarded material from the separator and dust collector and all shot losses… Industry use of techniques Company: UKAEA. Comment: Abrasive cleaning is used in Winfrith and Harwell. B 393.6 at Harwell used variety of abrasive cleaners (simple rotary drills with sanding plates and rotary files etc), adapted for use in shielded cells. Grit blasting also used. Grit blasting more effective, but recovery of grit debris can be harder. Worked well with steel but residual contamination left when used for concrete… |
| References |
| [1] UK Strategy for the Management of Solid Low Level Radioactive Waste from the Nuclear Industry: UK Nuclear Industry LLW Strategy, Consultation Document, June 2009 [2] UK Management of Solid Low Level Radioactive Waste from the Nuclear Industry: LLW Management Plan NLWS/LLWR/05, Rev 1, December 2009. [3] Radioactive Substances Regulation Environmental Principles, Assessment Guide No 1 – Assessment of Best Available Techniques (BAT), Consultation Draft, June 2008. |
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