Thank you for the opportunity to provide comments on the ICRP¡¦s revised draft recommendations. Nirex also wishes to express its thanks to ICRP for addressing the comments made by Nirex us on the draft ICRP recommendations issued for consultation in 2004. We think the revised draft is a strong improvement on the previous version. However, we do have a few comments mentioned below. Nirex Nirex is a UK Government-owned body. Our mission is: "In support of Government policy, develop and advise on safe, environmentally sound and publicly acceptable options for the long-term management of radioactive materials in the UK." Our current objectives are to: „h carry out scientific, engineering and social science research to help develop safe and environmentally sound options for dealing with radioactive waste in the long term; „h set specifications and standards based on a phased deep geological disposal concept and advise the industry on how to treat and package radioactive waste through the application of the Nirex Letter of Compliance pProcess; „h maintain an inventory of radioactive waste in the UK in conjunction with the Department for Environment, Food and Rural Affairs (Defra); „h communicate with all stakeholders, including the public, to build understanding and develop ways of addressing the wide range of concerns and views surrounding the management of radioactive waste, so that these influence our work. This work will be carried out adhering to UK Government policy at all times, ensuring no conflict or overlap with the work in the UK of the Committee on Radioactive Waste Management (CoRWM) or the Nuclear Decommissioning Authority (NDA). Collective dose We feel that the reasons why collective dose is not always an appropriate tool are not fully explained in paragraph 147. It would be helpful to explain that the reliability of collective dose as an indicator of total health detriment decreases where the exposures occur over long time periods, in large populations or across large geographical areas. Optimisation It is not clear whether the reference to "potential exposures" in section 8 refers to the consequences of accidents of unknown frequency (an operational issue), or the potential for a hypothetical member of the public to be exposed to an uncertain extent, for example to radioactivity emanating from a source such as a closed repository. It would be helpful if this could be made clear in paragraph 307. Paragraph 307 also refers to Publication 81 which is mainly concerned with post-closure risk from the repository (i.e. potential exposure of future individuals to certain releases). In contrast, paragraph 321 refers to optimisation of protection in terms of safety culture, sound engineering principles and experience. We feel that the distinction needs to be made that as the source of potential exposure would be from operational accidents, this would be affected by the safety culture. However, exposure from a closed repository would neither be affected by safety culture nor experience. We feel it would be helpful if paragraph 321 could be reordered to include the ERICPD (eliminate, reduce, isolate, control, protect and document) safety hierarchy and to reflect the primacy of passive, engineered controls over safety management systems in preventing unplanned exposures. If ICRP plans further work on optimisation of protection against accidents (the operational source of potential exposure), it would be helpful to note this in section 8. Exposures resulting in benefit to society society, but not to the individual It is not clear what is meant by the term ¡§the maximum value for a constraint¡¨ in the final sentence in paragraph 204. Does the text refer to a constraint of 1 mSv or 100 mSv? The sentence could be clarified by including the value in parentheses. Terminology We support the proposed change in terminology away from the current differentiation between practices and interventions, towards characterisation of possible situations where radiation exposure may occur as planned, emergency and existing exposure situations. We feel that this will result in improved clarity and confidence in the overall system of radiological protection. Typographical error Two separate tables in the recommendations on pages 35 and 61 have both been numbered as Table 4. We would welcome the opportunity to discuss these issues with you in more detail. If you require clarification about any of the points raised please contact my office. We would be grateful if you could send us a copy of the outcome of the consultation and add us to any list of interested consultees that you hold. Yours sincerely Chris Murray Chief Executive Direct Line: +44 (0) 1235 825264 Fax Number: +44 (0) 1235 821627 E-mail: chris.murray@nirex.co.uk