Papers in this volume: 7
1. Managing safety at Dounreay for the future
Author(s): Welsh P.
Page: 11
Keywords: Decommissioning, Dounreay, Improvement, Nuclear operations and safety, Public opinion, Radiation monitoring and dose management, Radioactive waste management - transport and disposal, Restoration Strategy for Radioactively Contaminated Sites (RESTRAT), Safety, United Kingdom Atomic Energy Authority (UKAEA)
Abstract: Between 1955 and 1993, the United Kingdom Atomic Energy Authority's (UKAEA's) site at Dounreay, with its development of fast reactor technology, was very much a pioneering R&D establishment. Now Dounreay's task is to restore its environment through the decommissioning of its facilities, the remediation of its land and the management of wastes, particularly radioactive wastes. As the site licensee, UKAEA must be able to demonstrate that all its activities are carried out safely, environmentally responsibly, and cost-effectively. This paper summarizes how it is intended to manage safety and environment at Dounreay in the future through a safety and environment management system as an integrated part of the site management system. The responses to the key concerns raised by the Nuclear Installations Inspectorate's recent audit are used to illustrate the intended approach.
2. To POCO or not to POCO, that is the question
Author(s): Gangahar M. and Phillips A.
Page: 17
Keywords: ALARP principle, Nuclear operations and safety, POCO (post-operational clean-out)
Abstract: The end of a facility's operational life generally means that removal/reduction of any residual hazard will be necessary. This phase is known as post-operational clean-out (POCO) and provides a safe environment for the period of care and surveillance prior to the start of dismantling work. The amount of POCO work required will depend upon the type of process undertaken at the facility and the degree of radioactivity or toxicity present. This paper presents a methodology for assessing the overall requirements for POCO, both in terms of the need for and extent of such operations. Ultimately, the decision-making process should be based on the net benefit to be gained, that is, reduction in risk. It should be emphasized that if POCO is deferred until the dismantling phase the residual risk remains and is effectively transferred to the future decommissioning team.
3. Radiation safety for decommissioning projects
Author(s): Ross A.C.
Page: 21
Keywords: Contractors, Nuclear operations and safety, Radiation monitoring and dose management, Safety, United Kingdom Atomic Energy Authority (UKAEA)
Abstract: Decommissioning of redundant nuclear facilities is a growth area in the UK at the present time. NUKEM Nuclear Limited is a leading-edge nuclear decommissioning and waste management contractor (with its own in-house health physics and safety department), working for a variety of clients throughout the UK nuclear industry. NUKEM Nuclear is part of the prestigious, international NUKEM group, a world-class organization specializing in nuclear engineering and utilities technologies. NUKEM Nuclear is involved in a number of large, complex decommissioning projects, both in its own right and as part of consortia. This paper explores the challenges presented by such projects and the interfaces of contractor, client and subcontractors from the point of view of a radiation protection advisor.
4. Biodecontamination: cost-benefit analysis of a novel approach for decontamination of massic concrete structures
Author(s): Hamilton M.A., Rogers R.D., Nelson L.O., Holmes R.G. and Milner T.N.
Page: 29
Keywords: Concrete, Decommissioning, Decontamination
Abstract: A major liability facing the owners and operators of nuclear facilities worldwide is the decontamination and decommissioning (D&D) of contaminated massive concrete structures. A biodecontamination technology which harnesses the action of naturally occurring bacteria is currently under joint development by BNFL and the Idaho National Engineering and Environmental Laboratory. This emerging technology was judged to exhibit advantages in cost, worker health and safety risk reduction, and programmatic effectiveness. The process takes approximately six months to one year to remove the contaminated surface and can advantageously be applied during the care and maintenance phase of a D&D programme. A detailed assessment of the biodecontamination process in relation to the next best and base technologies was performed. The findings of this study, which recommended a large-scale technology demonstration, will be presented.
5. Management and remediation of radioactively contaminated land on nuclear licensed sites: a regulatory perspective
Author(s): Delaney B.
Page: 35
Keywords: Contamination, De-licensing, Decommissioning, Health and Safety Executive (HSE), Land, Regulatory issues, Remediation, Restoration Strategy for Radioactively Contaminated Sites (RESTRAT)
Abstract: The legislative framework allows HSE to regulate contaminated land on licensed sites. HSE considers land and materials contaminated with radioactivity to be radioactive waste and will regulate it accordingly. Licensees should address contaminated land in their strategies for managing radioactive wastes. Safety cases to justify those strategies should show what options have been considered and that risks imposed on present and future generations will be as low as reasonably practicable.
6. WAGR decommisioning: preparation, removal and disposal of the WAGR heat exchangers
Author(s): Dixon C.
Page: 39
Keywords: Advanced gas-cooled reactors (AGRs), Heat exchangers, Radioactive waste management - transport and disposal, United Kingdom Atomic Energy Authority (UKAEA), WAGR (Windscale advanced gas-cooled reactor)
Abstract: The Windscale advanced gas-cooled reactor (WAGR) operated between 1963 and 1981 and was used as a prototype for experimental research and development related to the advanced gas-cooled reactor programme. Operations ceased in 1981 and the defuelling and dismantling of WAGR became a focus for the development of decommissioning and decontamination techniques. A major operation in the decommissioning of WAGR was the removal of the four heat exchangers (HEs) from their concrete bioshields inside the secondary containment sphere and their subsequent disposal as low-level waste. This paper describes how the removal and disposal of these HEs was planned, organised and implemented.
7. Private nuclear electricity in the UK: uncertain trade-offs in its future
Author(s): Pena-Torres J.
Page: 49
Keywords: Carbon taxes, Economic assessment, Electricity, Energy, Energy taxes, Fossil fuel comparisons, Gas-fired electricity, Global warming, Liberalized generation markets, Nuclear electricity, Nuclear power, Radioactive waste, Radioactive waste management - transport and disposal, United Kingdom
Abstract: This paper discusses whether new nuclear reactors, subject to current technology, could have market support in the coming decades in the UK when current generation capacity will start being decommissioned and UK CO2 emissions may be priced. We focus on a case where gas-fired generation remains as the relevant marginal market benchmark. Our discussion is based on well-documented sources of expected costs for nuclear and gas-fired generation. In the nuclear side, we discuss capital and back-end costs. We then discuss ranges of hypothetical carbon/energy taxation that would equalize the levelized costs of gas-fired and nuclear electricity. For the policy context assumed in this paper, and after giving proper weight to the political acceptability of such a pricing measure, we conclude that, leaving aside the possibility of a major breakthrough in nuclear technology, it seems unlikely that privately-owned new reactors could win market space, within a liberalized generation market, during the coming decades in the UK.