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Protection of the Environment from Ionising Radiation in a Regulatory Context. CEH SSI IRSN NRPA (+ UMB) EA. PROTECT - Overall Objectives. E valuate the practicability and relative merits of different approaches to protection of the environment from ionising radiation.
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Protection of the Environment from Ionising Radiation in a Regulatory Context CEH SSI IRSN NRPA (+ UMB) EA
PROTECT - Overall Objectives • Evaluate the practicability and relative merits of different approaches to protection of the environment from ionising radiation. • Compare these with methods used for non-radioactivecontaminants, particularly on the adequacy with respect to the European framework defined for chemicals.
PROTECT will provide: • A basis on which the EC could develop protection policies and revise its Basic Safety Standards, • a fruitful collaboration with, and constructive input into, current ICRP and IAEA task groups.
Work packages WP 1: Environmental Protection Concepts WP 2: Assessment approaches: practicality, relevance and merits WP 3: Requirements for protection of the environment from ionising radiation WP 4: Management
Resources • Full cost: 582k Euro • EC contribution 347k Euro • Expert group meeting 80k Euro • Labour 33 months
Objective of WP1 • Consult widely with industry and regulators to review regulatory approaches to chemical and radioactive substances. • Our emphasis was on: • Regulatory instruments • Procedures • Underlying principles • Criteria • What is on the horizon (policy development)?
WP 1: Implementation • Information gathering (questionnaires, face to face, phone calls, website review) • Review of the information to identify similarities and differences in how chemicals and radioactive substances are regulated • Included assessment of relevant ecological and biological endpoints of protection
Of 18 regulators, 15 state they regulate to protect the environment Most rely on ICRP statement that if man is protected…
Regulation • PROTECT should not treat TeNORM differently to other radioactive substances (WP3) • Emphasis on the positive benefits of regulation for the nuclear and non-nuclear sectors • able to demonstrate behaving in an appropriate and responsible manner (G) • Optimisation of discharges should remain central to environmental/human radiological protection (G) • Harmonise future international guidelines and recommendations (G)
Protection Goals • Protection should focus on the population level although rare or endangered speciesshould be explicitly considered (WP3) • Protection goals should be translated into measurable targets and advice provided on tolerable risks associated with these endpoints (WP3) • Develop similarities between radiological protection and chemicals assessment processes. There are some technical differences but the underlying protection goals are identical (WP3) • PROTECT should work together with IAEA and ICRP (G)
Assessment Methods • PROTECT should consider the followingapproaches to assessing radiological risks to biota(WP2) • R&D 128 • ERICA • RESRAD • Other approaches as identified within IAEA EMRAS programme • ICRP approach
Risk Characterisation - methods • PROTECT should consider (WP3) • Literature values (expert judgement) • Assessment Factor approach • Species Sensitivity Distribution approach • Use of background levels • PROTECT should focus on SSD and AF approaches to determine benchmark dose rates based on agreed tolerable risks. • The use of expert judgement only should be avoided where possible (WP3) • The level of conservatism in the benchmark should be identified and recorded (WP3)
Risk Characterisation - benchmarks • PROTECT should assess the use of the numeric values currently being applied or suggested (WP2) • PROTECT should consider the use of a screening value (WP3) • PROTECT should consider the need for a standard number (i.e. an equivalent to the 1 mSv for public) (WP3) • What are the advantages and disadvantages of having a screening level and a standard? • Advice will be needed if either a screening level or a standard is exceeded (WP3) • PROTECT should produce a clearly understandable document outlining the derivation and limitations. This document should be developed in consultation with stakeholders (WP3)
Compliance • Methods for demonstrating compliance should be evaluated (bearing in mind the use of any identified threshold(s) eg, if used as a regulatory limit then clear strong compliance will be needed) Improving the process • We should continue to communicate in an open and transparent manner with clear documentation
WP3: Objectives • derive and propose numerical target values for an extended list of ecological targets and protection levels, designed to assure compliance with environmental protection goals that resonate with protective goals set up for releases of hazardous substances in general, and to assess the implications for society at large
WP3: Four areas • The appropriate level of protection of the environment against ionising radiation • Derivation of numerical target values • Analysis of implications of derived values for practices • Interaction with regulators, industry, NGO’s and other experts
WP3 : progress prior to Aix workshop • Initial ideas presented in Oslo Jan 08 • Extensive consideration of Oslo meeting discussions and recommendations in Winter / Spring 08 • Preparation of Draft D5 • Distribution of Draft for comment
Oslo: take home messages (1) • PROTECT should consider points such as transparency, periodic review); • WP2 has demonstrated the importance of clear problem formulation and sensitivity analyses; • General agreement on need for/use of a screening level dose rate for use in assessments; • General agreement on use of SSD for derivation of screening level • consistent with chemicals and allows updating as new data become available;
Oslo: take home messages (2) • General agreement of need for an ‘action level(s)’; BUT • Lack of agreement on how action level is derived nor what it actually is • recognised that procedures used to set it should be scientifically defensible and it should be easy to defend legally (but this relies on knowing what a level of significant harm actually is); • Need to consider implications of including in environmental management the precautionary principle, optimisation etc. • differences between the screening and action levels could be related to how optimisation might be applied to environmental protection • any action that is taken must be proportional to the risk and should do more good than harm;
Oslo: Extra points PROTECT should: • test any numeric values derived as a standard or screening value. • include a critical review and/or evaluation against field data on biological effects caused by exposure to ionising radiation to ground truth any number; • make it clear what values are being applied within the suggested protection goals proposed by PROTECT WP3; • highlight where data gaps exist, • implications of data gaps for deriving standards, thresholds or action limits • recommend further work required; • clarify data included in the SSDs and consider how the data points used are constructed (eg using jack-knife type procedures to select data points); • should continue to request and highlight the need for others to provide papers which describe biological effects in non human species resulting from exposure to ionising radiation; • arrange for a presentation in Aix on ‘pros and cons’ of using SSD;
Draft D5 The focus of the report is to suggest: • a coherent approach encompassing relevant protection goals - matching measurement and assessment endpoints • meaningful and usable conceptual benchmarks derived by transparent and scientifically justifiable methodologies.
Generic screening • Application of a screening tier enables sites potentially at risk to be identified whilst excluding from further assessment those which present no risk, thereby making best use of resources. • A simple, ideally generic, conservative benchmark which can be applied across species and preferably ecosystems. • Use of this value is to screen out situations of no concern when dose rates are below the screening level. • Inputs and parameters used within the initial screening tier of assessment models are conservative • If the dose rate to populations of any species estimated from assessment exceeds the generic screening value, this only tells the assessor that a more realistic assessment of the site is warranted. • The generic screening level is notproposed as a prescriptive limit which must not be exceeded.
Regulatory action levels Justification for an action level • the need to be consistent with the approach for human radiological protection; • a requirement to have a robust, defensible regulatory action level above which it is likely that significant harm would be caused to the environment; and • the need for a value which can act as an upper threshold below which the regulatory action would be to encourage optimisation of operational practices to drive environmental dose rates to a level close to or below that of the screening level.
Optimise down (BAT, ALARA etc.) Action required – BUT ‘more good than harm’ Regulatory Action Level Generic Screening Level No further assessment required
Aix meeting: Purpose • To discuss outcome of wp3 (Draft D5) • with relevant international bodies and other experts • To identify the issues which can be • commonly agreed • NOT commonly agreed • Way forward in PROTECT and thereafter