The British Radwaste Information Management System (BRIMS)

The creation and subsequent access to accurate information is widely accepted as a vital component of a national radioactive waste management strategy. Information on the origin and quantity of the waste together with its physical, chemical and radiological characteristics provides a catalyst for sound and transparent decision making. This information will originate from a number of potentially disparate sources, including material manufacturers, facility operators, waste producers, Government and Non-Government organisations and regulators. The challenge to those with a role in information management in further increased by the fact that much of the information created is required to support activities, not only in the immediate future, but also in the longer-term — typically many decades or even centuries. The International Atomic Energy Agency (IAEA) has published a number of guidance documents under the Safety Series, one of which makes direct reference to information management. The document [1] is intended to assist Member States in the development of a national system for radioactive waste management and identifies the key responsibilities and essential features of such a system. The following statement appears in Section 5: “The regulatory body, the waste generators and the operators of radioactive waste management facilities should maintain documentation and records consistent with the legal requirements and their own needs.” An essential requirement of these ‘documents and records’ is that they should be “...kept in a condition that will enable them to be consulted and understood later by people different from, and possibly without reference to, those who generated the records ...” The scope of the documentation and records to be kept will be wide ranging but will include “...an inventory of radioactive waste, including origin, location, physical and chemical characteristics, and, as appropriate a record of radioactive waste removed or discharged from a facility”, and “site plans, engineering drawings, specifications and process descriptions ... radioactive waste package identification ...”. It is has long been recognised in the United Kingdom that the management of radioactive waste will require the assembly and secure retention of a diversity of records and data. This information will be needed to inform the strategic decision making process, thus contributing to the future safe, environmentally sound and publicly acceptable management of radioactive waste. In the meantime it will also service the nation’s international commitments. When the planning application for a Rock Characterisation Facility (RCF) was refused and the subsequent Nirex appeal rejected in 1997, it was recognised that transfer of waste to a national repository was ulikely to take place for many decades. The long-term preservation of information by the waste management organisations thus became an issue. Since this time, the UK nuclear industry, including the waste producers, regulators and other Government Departments have worked together to develop a common information management system that is now being implemented. It is based on an Oracle database and is supported by ‘electronic tools’ designed to facilitate entry and retrieval of data in a common format. Long-term access to these data underpins many aspects of the system design. Designing such a system and seeing through its development has been a challenge for all those involved. However, as the project nears the completion of the development phase, it is clear there are several benefits in this approach. These include a sharing of best practice, shared development costs, an improved understanding of the needs of all parties, and the use of a common platform and tools. The ‘partnership approach’ between waste management organisations, Government departments and regulators will also reduce the likelihood of future surprises or conflicts of interest. Industry-wide co-operation also provides a greater degree of confidence that the system will continue to enjoy technical and financial support for the foreseeable future. The British Radwaste Information Management System (BRIMS) is supported by the principal waste producers, the Department for Environment, Food and Rural Affairs (DEFRA), the Nuclear Installations Inspectorate (NII) and United Kingdom Nirex Limited (Nirex). All organisations that have participated in its development over the past seven years have free access to it and may use it as part of their waste management strategy.

Current Status of Radioactive Waste Disposal in Russia

A huge amount of radioactive waste has been accumulated in the Russian Federation (RF) in the course of implementation of the defense and energy programs, industrial and research activity involving the use of nuclear materials. The most justified and technically feasible technology of solidified RW isolation is its disposition in low-permeable geological formations in specially constructed underground facilities. Today in Russia a Closed Fuel Cycle (CFC) has been adopted, at the CFC final stage the spent nuclear materials and radioactive waste have to be isolated from the biosphere for the whole term of their potential hazard. In Russia, in accordance with the regional approach to the decision of Radioactive Waste (RW) disposal problem, several candidate disposal sites have been assigned.

Self-Sustaining Immobilisation Processes

As overview of self-sustaining immobilisation processes is given which describes also new thermochemical and radiogenic heat immobilising schemes based on utilization of both exothermal chemical reactions and radioactive decay energy.

Experience in Operating Mobile Solidification Plant for BNFL Environmental Services

UK power stations have generated wet radioactive wastes, principally from operation of treatment plants for cooling pond water and liquid effluents. These include ion exchange resins, filter backwash sludges, flocs, pond sludges, filter aids, and miscellaneous oily sludges. To treat these wastes, it was concluded that mobile plants offered significant benefits compared with the alternative of constructing fixed installations. NSG Environmental Ltd designed and built a Mobile LLW Solidification Plant, which we have operated on behalf of BNFL Environmental Services and its predecessors for over twelve years. Since commencing active operations in 1991 the plant has successfully performed 28 campaigns on 13 nuclearlicensed sites. A total of nearly 3,000 drums of active waste have been processed during those campaigns. There have been no failures to solidify wastes, no excessive doses to operators and no transport incidents.

Information Overload: Processing Consultation Responses From Experts, Stakeholder Groups and Communities

Contemporary approaches to the design and implementation of consultation programmes have come a long way from the days of ‘decide-announce-defend’. However success in expanding involvement and combining different participation methods, especially within a complex multi-phase programme, still poses major challenges. This paper discusses one of them: processing the much increased volume and variety of contributions received and then combining them with other forms of input in a rigorous, balanced, auditable and transparent manner. It is no longer sufficient, if indeed it every really was, for someone simply to work their way through a stack of comments with a highlighter, altering a draft text where he or she judged that clarification was required. We illustrate the nature of the challenge and the response of the Environment Agency of England and Wales by considering some specific issues, including the following. • Applicability of systematic approaches to text and transcript analysis; • Use of qualitative data management systems; • Transparency vs confidentiality; • Inconsistencies between stakeholder/public concerns and regulatory boundaries; • Integration of different types of input; • Deciding what to take into account; judging validity and weight; • Implications for quality management, documentation and resources; • Approaches to programme evaluation.

A Temporary Store for Radioactive Waste

To provide an efficient process for the final disposal of radioactive wastes, some nuclear sites are currently building suitable, temporary stores for such material. This paper describes the practical construction programme recently completed at a UK power reactor site under decommissioning. This site has a number of half height ISO containers filled with solid radioactive material that needed a temporary storage area before being consigned for final disposal. As a result, the site, Hunterston A Decommissioning Site, needed to construct some temporary radiation shield walls to contain the half height ISO containers (HHISO) and safeguard staff and public during the storage period. The chosen location of the temporary store was the Charge Machine Maintenance Building (CMMB), which was surplus to requirements during the decommissioning programme, providing a weatherproof environment. Following an in-depth study of the different forms of construction available, the commercially available, hollow, interlocking polyethylene block system was adopted. Because of its modular form, it has the advantage that it can to be dismantled and re-used at other locations, if required. Being hollow, the block could be filled with a variety of materials, such as water, sand, lead or iron shot, depending on the radioactive shielding needs. An important aspect of the modular plastic block was that it could be more easily installed, decontaminated and decommissioned than the cheaper concrete block system, which produces copious quantities of waste for disposal. This paper describes the choice of interlocking block shielding after comparisons with more conventional forms of construction, the features of the HHISO store design, the short duration building programme and the on-site experiences of the construction period.

Vitrification of HLW Produced by Uranium/Molybdenum Fuel Reprocessing in COGEMA’s Cold Crucible Melter

The performance of the vitrification process currently used in the La Hague commercial reprocessing plants has been continuously improved during more than ten years of operation. In parallel COGEMA (industrial Operator), the French Atomic Energy Commission (CEA) and SGN (respectively COGEMA’s R&D provider and Engineering) have developed the cold crucible melter vitrification technology to obtain greater operating flexibility, increased plant availability and further reduction of secondary waste generated during operations. The cold crucible is a compact water-cooled melter in which the radioactive waste and the glass additives are melted by direct high frequency induction. The cooling of the melter produces a soldified glass layer that protects the melter’s inner wall from corrosion. Because the heat is transferred directly to the melt, high operating temperatures can be achieved with no impact on the melter itself. COGEMA plans to implement the cold crucible technology to vitrify high level liquid waste from reprocessed spent U-Mo-Sn-Al fuel (used in gas cooled reactor). The cold crucible was selected for the vitrification of this particularly hard-to-process waste stream because it could not be reasonably processed in the standard hot induction melters currently used at the La Hague vitrification facilities: the waste has a high molybdenum content which makes it very corrosive and also requires a special high temperature glass formulation to obtain sufficiently high waste loading factors (12% in molybednum). A special glass formulation has been developed by the CEA and has been qualified through lab and pilot testing to meet standard waste acceptance criteria for final disposal of the U-Mo waste. The process and the associated technologies have been also being qualified on a full-scale prototype at the CEA pilot facility in Marcoule. Engineering study has been integrated in parallel in order to take into account that the Cold Crucible should be installed remotely in one of the R7 vitrification cell. This paper will present the results obtained in the framework of these qualification programs.

Direct Push Technology and Application to Vertical Profiling of Hydraulic Conductivity in Unconsolidated Formations

Direct push (DP) methods provide a cost-effective alternative to conventional rotary drilling for investigations in unconsolidated formations. DP methods are commonly used for sampling soil gas, soil and groundwater; installing small-diameter monitoring wells; electrical logging; cone penetration testing; and standard penetration tests. Most recently, DP methods and equipment for vertical profiling of formation hydraulic conductivity (K) have been developed. Knowledge of the vertical and lateral variations in K is integral to understanding contaminant migration and, therefore, essential to designing an adequate and effective remediation system. DP-installed groundwater sampling tools may be used to access discrete intervals of the formation to conduct pneumatic slug tests. A small-diameter (38mm OD) single tube protected screen device allows the investigator to access one depth interval per advancement. Alternatively, a larger diameter (54mm OD) dual-tube groundwater profiling system may be used to access the formation at multiple depths during a single advancement. Once the appropriate tool is installed and developed, a pneumatic manifold is installed on the top of the DP rod string. The manifold includes the valving, regulator, and pressure gauge needed for pneumatic slug testing. A small-diameter pressure transducer is inserted via an airtight fitting in the pneumatic manifold, and a data-acquisition device connected to a laptop computer enables the slug test data to be acquired, displayed, and saved for analysis. Conventional data analysis methods can then be used to calculate the K value from the test data. A simple correction for tube diameter has been developed for slug tests in highly permeable aquifers. The pneumatic slug testing technique combined with DP-installed tools provides a cost-effective method for vertical profiling of K. Field comparison of this method to slug tests in conventional monitoring wells verified that this approach provides accurate K values. Use of this new approach can provide data on three-dimensional variations in hydraulic conductivity at a level of detail that has not previously been available. This will improve understanding of contaminant migration and the efficiency and quality of remedial system design, and ultimately, should lead to significant cost reductions.

Soil Based Barriers for a Low and Intermediate Level Radioactive Waste Disposal

The loess terrains near “Kozloduy” NPP are among the prospective areas for the disposal of low and intermediate level radioactive waste. The analysis of the loess properties has shown two main problems: a loess collapsibility and water permeability. Using a soil-cement cushion under the repository foundation and a soil-cement backfill between the containers is a possibility to avoid these disadvantages. In this connection loess-cement mixtures with bentonite and clinoptilolite additives have been investigated. The aim of mixtures is to improve the impermeability and sorbtion properties against radionuclide migration. In the paper strength parameters of two kind of mixtures are discussed. According to their water content some are compacted at the optimum moisture content until the maximum dry density and others are compacted at higher moisture content equal to the liquid limit of loess. For the first type of mixtures the unconfined compressive strength (UCS) varies from 2 to 6 MPa depending on the cement and additives percents. Permeability measurements have shown satisfactory results. The UCS for the second type of mixtures is less than the first type, but is sufficient for a backfill between the waste containers. The conclusion is that the loess-cement mixtures, especially these with clinoptilolite additive, are prospective as barriers of a low and intermediate level radioactive waste repository.

A Finite Element Computer Model for the Application of Electrokinetics to Contaminated Land

The computer code TRAFFIC incorporating three-dimensional (3-D) electrokinetic capabilities, coupled flow, transport and chemical speciation, using a finite element approach has been used to replicate published laboratory scale experiments [1, 2]. Two test cases have been presented using TRAFFIC with chemical speciation options and the Euler-Lagrangian transport formulation. The first of these (Case A with graphite anode) provided useful insights into the capabilities of the code to simulate realistic and complex problems, while the second (Case B with iron anode) closely reproduced the experimental results. It was also shown that the Euler-Lagrangian transport scheme was much better in coping with the steep chemical gradients, whereas the standard Euler scheme is less stable. Given the good results of these test cases, it is concluded that the code has been verified and partially validated.