REGULATORY IMPLICATIONS OF THE NEW DOSE LIMIT FOR LENS OF THE EYE Session Name: Regulatory Implications and Relevance Of The Revised Dose Limit For the Lens Of The Eye Speaker Details: Mrs Louisa Mpete

2nd NUCLEAR REGULATORY INFORMATION CONFERENCE Definition Dose Limit: The value of the effective dose to individuals in planned exposure situations that is not to be exceeded. Old Dose Limit ICRP-103/ BSS New Dose Limit Schedule III, GSR Part3, Eye Lens 150 mSv/a 20 mSv/a Dose Limits For Planned Exposure Situations An equivalent dose to the lens of the eye of 20 mSv per year averaged over 5 consecutive years (100 mSv in 5 years) and of 50 mSv in any single year;

2nd NUCLEAR REGULATORY INFORMATION CONFERENCE Presentation Outline Scientific Basis GSR Part 3 Requirements 3 . Regulatory Implications For implementing the new dose limit. 4. Conclusion

2nd NUCLEAR REGULATORY INFORMATION CONFERENCE SCIENTIFIC BASIS EYE LENS doses have received a lot of attention in the last years because of some epidemiological studies on Chernobyl clean-up workers and survivors of the A-bomb (Worgul et al., 2007, Junk et al). The eyes of a prospective cohort of 8,607 Chernobyl clean-up workers were assessed for cataract at 12 and 14 years after exposure. 90% of the cohort was younger than 55 years of age at first examination. The conclusions of these recent studies have suggested that the lens of the eye may be more radiosensitive than previously considered, why? Because there is evidence of excesses of both cortical and Posterior Sub- Capsular Cataract Characteristic of radiation exposure at doses somewhat lower than expected. Cataract is the loss of transparency of the lens of the eye. The cataracts progress slowly to cause vision loss and may eventually lead to blindness.

GSR PART 3 REQUIREMENTS Requirement 12 : Dose Limit 2nd NUCLEAR REGULATORY INFORMATION CONFERENCE GSR PART 3 REQUIREMENTS Requirement 12 : Dose Limit The government or the regulatory body shall establish dose limits for occupational & public exposure, and registrants and licensees shall apply these limits. 2) Requirement 13 : Safety Assessments The regulatory body shall establish and enforce requirements for safety assessment, and the person or organization responsible for a facility or activity that gives rise to radiation risks shall conduct an appropriate safety assessment of this facility or activity. Requirement 14: Monitoring for verification of compliance Registrants and licensees and employers shall conduct monitoring to verify compliance with the requirements for protection and safety.

2nd NUCLEAR REGULATORY INFORMATION CONFERENCE GSR PART 3 REQUIREMENTS 4) Requirement 24: Radiation Protection Programme Employers, registrants and licensees shall establish and maintain organizational, procedural and technical arrangements for the designation of controlled areas and supervised areas, for local rules and for monitoring of the workplace, in a radiation protection programme for occupational exposure. 5) Requirement 26: Information, instruction and training Employers, registrants and licensees shall provide workers with adequate information, instruction and training for protection and safety. 6) Requirement 25: Health surveillance Assessment of occupational exposure and workers’ health surveillance Employers, registrants and licensees shall be responsible for making arrangements for assessment and recording of the occupational exposure and for workers’ health surveillance.

REGULATORY IMPLICATIONS 2nd NUCLEAR REGULATORY INFORMATION CONFERENCE REGULATORY IMPLICATIONS The licensees to investigate and identify the groups of workers at risk and the doses that they might receive. Monitoring of the identified workers using the appropriate dosimeters for the eye lens. Amendment of the Worker Safety Assessment based on the revised monitoring programme, amended to take into account the new dose limit for the lens of the eye. Amendments to Radiation Protection Programme to implement individual dosimetry for the lens of the eye. Review and Amended Personal Protective Equipment. Training (Affected Workers, RPO, RPS, Dosimetry Service providers, Nuclear Regulator). Revision of Local Rules and Procedures.

2nd NUCLEAR REGULATORY INFORMATION CONFERENCE CONCLUSION The reduced dose limit to the lens of the eyes has Regulatory Implications. The most accurate method for monitoring the equivalent dose to the lens of the eye, Hlens, is to measure the personal dose equivalent at 3 mm depth, Hp(3), with a dosimeter worn as close as possible to the eye. NNR is in the process of updating its Regulations, the revised dose limit has already been adopted by the NNR in the draft Radiation Protection Regulations.