The scope of radiological protection


Draft document: The scope of radiological protection
Submitted by Prof Brian O'Connor, Alcoa World Alumina Australia
Commenting on behalf of the organisation

Review of ICRP Publication Draft The Scope of Radiological Protection Regulations (Document 02/258/05 – Spring 2006 version) Prepared for Alcoa World Alumina Australia by Brian H O’Connor SUBMISSION TO ICRP Introduction: Alcoa World Alumina Australia (Alcoa) welcomes the opportunity to comment on the ICRP draft Publication The Scope of Radiological Protection Regulations (Document 02/258/05 – Spring 2006 Version). Alcoa supports the general approach proposed in the draft Publication which will provide timely and useful guidance to industry and the general public as well as regulators. In particular, the graded approach to determining exemption provisions for the handling of bulk materials proposed in the draft Publication will promote the protection of worker and public health while supporting exemptions for activities that do not pose a discernible risk to health. This response provides advice with respect to: • Alcoa’s Experience in Radiological Management • Graded Approach to Regulation and Associated Protection Optimisation • Radon Workplace Exemption Provisions The response follows recent Alcoa submissions to the ICRP, to the IAEA and to the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) which relate to this response, as detailed below. Alcoa would welcome the opportunity to provide further advice and input as the draft Publication is being finalised. Alcoa’s Experience in Radiological Management: Alcoa World Alumina Australia is a leading alumina and aluminium producer. Alcoa’s operations account for around 13 per cent of total world demand for alumina. Alcoa has been studying the radiological aspects of its bauxite processing operations in Western Australia (WA) for 25 years (O’Connor, 2004a). Alcoa has demonstrated that incremental radiation doses (i.e. above the local natural background radiation) for its workforce and for the general public fall below the limit prescribed for members of the public (1 mSv/year) by the relevant regulator, the Radiological Council of Western Australia. It has also demonstrated to the regulator its strong commitment to protection optimisation through the ALARA principle. The broad conclusions from a succession of radiological studies conducted by Alcoa over many years have been – • The radioactivity levels for the various material categories do not exceed the currently prescribed ‘30 Bq/g’ regulatory limit (as the total activity for U-238 and Th-232 and their progeny assuming secular equilibrium) if the time-averaged activity data are considered for each of its bauxite processing operations in Western Australia. • Assessments of incremental dose for the Alcoa workforce and for the general public indicate that there is compliance with the exemption limits set for the general public by the regulator. • Alcoa has demonstrated its strong commitment to the ALARA principle in its protection optimisation initiatives. • Alcoa has shown that rehabilitation of residue areas for selected uses is possible, and that there are radiologically acceptable end-uses for residue materials. Alcoa is working to further improve its strategic management of radiological issues by implementing a quality-assurance based radiological management system. The management system will be both retrospective and prospective and will have the following key elements: 1. A radiological strategic plan based on (i) a review of work conducted to date, (ii) annual plans for future years, and (iii) procedures/criteria for evaluating progress. 2. Key documentation - mainly details of current and prospective codes and regulations, as well as key items of correspondence. 3. Technical data reporting the activity of the materials, dose assessments and environmental impact data. 4. ALARA compliance information from a strategic perspective. Key aspects of the proposed system are external review of the strategic plan and annual reviews of progress. It is expected that the system will be ISO compliant. In this way, Alcoa’s existing radiation exposure assessment program is to be incorporated into Alcoa’s broader occupational hygiene and environmental impacts assessment programs to cover matters of radiological interest. This will involve an on-going commitment to personal monitoring and positional sampling. Recent Alcoa Responses to ICRP, IAEA and ARPANSA which Relate to This Submission: Alcoa has engaged in current international and national initiatives on the regulation of low-activity NORM materials by preparing the following response documents. Copies are available from the Company. • Response to the ICRP Draft Document Recommendations of the International Commission on Radiological Protection (O’Connor, 2005a) • Review of IAEA Draft Safety Report Assessing the Need for Radiological Protection Measures in Work Involving Minerals and Raw Materials (O’Connor, 2005c) • Response to ARPANSA Document Naturally-Occurring Radioactive Material (NORM) in Australia: Issues for Discussion - 30 June 2004 (O’Connor, 2004b) • Response to ARPANSA Related Documents: • Protocol for Application of Exemption Provisions for Radioactive Material • Code of Practice and Safety Guide - Radiation Protection and Radioactive Waste Management in Mining and Mineral Processing - August 2005 • Regulatory Impact Statement for the Code of Practice and Safety Guide (O’Connor, 2005b) Alcoa Comments on the ICRP Draft Publication: Section 3. Dichotomous Control Paragraph 31 on the Regulation of Both ‘Artificial and ‘Natural’ Sources within a Single Framework Alcoa endorses in principle the new approach proposed by the Commission in regulating the use of both ‘artificial’ and ‘natural’ sources within a single framework. The key to this approach is the proposed graded exemption strategy for dealing with bulk low-activity materials which is linked to protection optimisation. This approach should be adopted for both NORM materials and their residues in industrial processing Section 4. Unamenable Control: Exclusion Paragraph 35 on the Difficulties Which Would Presented by Exclusion from Regulation of All Unmodified Raw Materials Alcoa appreciates that exclusion from regulation of all unmodified raw materials would be unworkable given that NORM material with activity concentrations well above 1 Bq/g may require regulation. Section 5. Unwarranted Control: Exemption Paragraph 40 on Exemption Principles The principles underpinning the exemption guidelines specified in the IAEA document BSS-115 (IAEA, 1996), as summarised in the paragraph, are reasonable. However, from the issue of BS-115 in 1996 until 2004, there had been considerable uncertainty about the practical application of these principles to the industrial processing of large-volume, low-activity materials. Publication of the IAEA report RS-G-1.7 (IAEA, 2004) has helped considerably with respect to the regulation of such materials, and appears likely to lead to the development by the Australian agency ARPANSA of helpful guidance for local regulators. Paragraphs 41- 50 on the Principles of Low Individual Risk It is difficult for readers to fully appreciate the complexities of this section until the complete text is read in fine detail. It would be helpful if the essence of the text in paragraphs 47, 49 and 50 on NORM materials regarding the 1 mSv guidance, plus the associated protection optimisation principles, could be introduced at the start of section 5.2 on Exemption Principles. Paragraph 54 on Transport Regulations It would be generally helpful for industry and for regulators if this ICRP publication could overview the transport regulations (IAEA, 2005) with reference to bulk NORM materials. Alcoa suggests that the present IAEA transport code document does not appear to deal adequately with the transport of bulk, low-activity materials. Paragraph 55 on Exemption Provisions for Bulk Materials The text as stated helps to further clarify the exemption principles applying to bulk materials. Section 6. Consideration of Some Specific Situations Paragraphs 90 - 95 on the Use of Materials Containing Radionuclides of Natural Origin These paragraphs summarise very clearly the earlier material in the draft Publication on exemption principles. In particular, the text on international agreements for commodities (paragraph 94) will help considerably given speculation that exemption limits for commodities transportation might be set well below 1 Bq/g by some national regulators. Paragraphs 103 - 115 on Radon Exposure The material on radon in the workplace and for the general public will be most helpful to Alcoa in reviewing and planning strategies with respect to radon. The workplace levels within the Alcoa operations are well below the proposed exemption level. Paragraphs 116 - 120 on Commodities This material provides valuable clarification of the exemption principles for international trade, notably in relation to the use of the 1 mSv guidance for bulk materials and associated protection optimisation. Concluding Comment: Alcoa would welcome the opportunity to provide further advice or support as the Publication is being finalised. References: IAEA [1996]. Basic Safety Standard for Protection Against Ionizing Radiation and for the Safety of Radiation Sources, Safety Series No. 115. IAEA [2004]. Application of the Concepts of Exclusion, Exemption and Clearance. IAEA Safety Series, Safety Guide RS-G-1.7. IAEA [2005]. Regulations for the Safe Transport of Radioactive Materials. IAEA Safety Standards, Safety Requirements TS-R-1. O’Connor, B.H. [2004a]. Bayer Process Radiological Evaluation: Status Review 2004. (Commercial-in-Confidence consultancy report). O’Connor, B.H. [2004b]. Response to ARPANSA Document Naturally-Occurring Radioactive Material (NORM) in Australia: Issues for Discussion - 30 June 2004. November 2004. O’Connor, B.H. [2005a]. Response to the ICRP Draft Document Recommendations of the International Commission on Radiological Protection. February 2005. O’Connor, B.H. [2005b]. Response to ARPANSA Related Documents: • Protocol for Application of Exemption Provisions for Radioactive Material • Code of Practice and Safety Guide - Radiation Protection and Radioactive Waste Management in Mining and Mineral Processing - August 2005 • Regulatory Impact Statement for the Code of Practice and Safety Guide. February 2005. O’Connor, B.H. [2005c]. Review of IAEA Draft Safety Report Assessing the Need for Radiological Protection Measures in Work Involving Minerals and Raw Materials. November 2005. ATTACHMENT 1. RADIOLOGICAL TERMINOLOGY Activity: Number of transformations from a radionuclide state per unit time. The activity is often taken as a measure of the quantity of radionuclide. Unit: the becquerel (Bq) = one transformation per second ALARA: An acronym for ‘as low as reasonably achievable’, used in the context of radiation protection optimisation ARPANSA: Australian Radiation Protection and Nuclear Safety Agency Clearance: The removal of radioactive materials or objects within authorised practices from any further control by the relevant regulatory authority Dose Equivalent (DE): Modified measure of absorbed dose designed to quantify the radiation damage induced in a given absorber for a specified radiation type of stated energy. The absorbed dose D converts to DE using an appropriate quality factor (QF) such that DE = D x Q x DF where DF is the distribution factor. Unit of DE: sievert (Sv). For gamma radiation, D and DE are numerically equal for gamma radiation. Exclusion: Deliberate exclusion from regulatory control because it is not considered amenable to control through the regulatory system Exemption: The determination by a regulatory body that a source or practice need not be subject to some or all aspects of regulatory control on the basis that the exposure (including potential exposure) due to the source or practice is too small to warrant the application of those aspects Incremental Effective Dose Equivalent: The summation of the components of the effective dose equivalent measured above local background. Unit: sievert (Sv). Ionizing Radiation: Electromagnetic radiation or particulate radiation capable of producing ions directly or indirectly, but does not include electromagnetic radiation of a wavelength greater than 100 nanometres (ARPANSA exclusion). NORM: Naturally occurring radioactive material. Radiation: Electromagnetic waves or quanta and/or sub-atomic particles, propagated through space or through a material medium. Radioactive Material: Technical definition: Material that emits ionizing radiation spontaneously. Regulatory definition: Material designated in national law or by a regulatory body as being subject to regulatory control because of its contained radioactivity. ATTACHMENT 2. AUTHOR DETAILS Brian O’Connor is a radiation physicist with many years experience in the use of x-rays, synchrotron radiation and neutron scattering for materials research, and in radiation safety with particular reference to the radiological aspects of mineral processing. Relevant experience includes: Curtin University of Technology Current appointment: Emeritus Professor, Department of Applied Physics Tenured staff member from 1971-2003, culminating in the award of a Personal Chair in 1990 as Professor of Applied Physics. Head, Department of Applied Physics: 1982-1984, 1987-1991 Head, School of Applied Science/Physical Sciences, 1993-2003 Radiation Safety Officer Chair, Radiation Safety Committee Western Australia Radiological Council of Western Australia: 1985-1991, 1995-1997 National Council, Australian Institute of Nuclear Science and Engineering (AINSE): 1990-2006 – currently Vice President Advisory Committee, Bragg Institute, Australian Nuclear Science and Technology Organisation (ANSTO): 2003-2006 National Scientific Advisory Committee, Australian Synchrotron Project: 2002-2006 Radiation Science Consultancies Clients have included – Alcoa World Alumina Australia – bauxite processing Allied Eneabba Ltd – rare earths processing Ashton Rare Earths Ltd (Mt Weld Rare Earths Project) – rare earths processing Australian Synchroton Project Chamber of Mines (WA) – mineral sands processing ICI Australia Limited – zircon processing Rhone Poulenc Chemie Australia Pty Ltd – rare earths processing Roxby Management Services Pty Ltd (Olympic Dam Project) – uranium mining SX Holdings Ltd – rare earths processing


Back