|NEWS AND INFORMATION
|Year : 2017 | Volume
| Issue : 1 | Page : 48-50
News and information
|Date of Web Publication||24-Apr-2017|
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
. News and information. Radiat Prot Environ 2017;40:48-50
| I. The International Radiation Protection Association (Irpa) Guidance on Implementation of Eye Dose Monitoring and Eye Protection of Workers|| |
Following the revision of the dose limit (equivalent dose) to the lens of eye and subsequent publication of the International Commission on Radiological Protection (ICRP) 118 report, the issues related to the implementation of the new dose limit have continuously been debated and followed by the International Radiation Protection Association (IRPA) since, 2012. IRPA associate societies were consulted through a questionnaire addressing issues related to eye lens dosimetry along with methods of protection and the same was completed in 2013. In January 2015, IRPA further established a task group with the aim to create positive and complete awareness about radiation protection in the workplace, with attention to exposure to eye lens and to collate current practitioner experience. The recently published report by IRPA which was approved by the executive council on January 31, 2017 provides guidelines about photon and beta radiations along with their importance in eye lens dosimetry and suggests that neutrons and heavy ions as well as alpha particles are not likely to contribute toward eye lens doses except to astronauts or in accident conditions. The report also suggests circumstances where eye lens doses may be required, or appropriate protection devices are needed.
In the guidelines on implementation of eye dose monitoring and protection of workers, IRPA stressed the need to identify workplaces where potential of receiving eye lens doses is high. In addition, it was recommended that the prospective doses to eye lens at such workplaces may be simulated through previous information, namely, whole body dose (WBD) records, beta and skin doses if any, nature of work and information about prevalent radiation fields, etc., Three situations for occupational exposure of workers were considered: (a) exposure to uniform whole body radiation fields which is the most frequent exposure situation, (b) exposure from weakly penetrating (low-energy photons and beta radiations) radiations mainly from beta particles having energy greater than 700 keV, as beta particles below this are not capable of depositing dose to eye lens which is typically at a depth of 3 mm, and (c) exposure from highly nonuniform radiation fields. Only in the last two situations, the estimate of potential doses to eyes may be required. In nuclear industry, the hot cell works, performing decommissioning, decontamination and maintenance jobs, handling liquid waste, etc., may lead to eye lens doses, whereas in medical sector, the main impact is likely to be in interventional cardiology and interventional radiology (IC/IR) and to some extent in nuclear medicine facilities.
IRPA has also recommended the proposed dose values/levels for implementing the dose monitoring and suggested that regular monitoring is required, if the annual doses are likely to be >6 mSv (>3/10 of the annual dose limit) whereas for dose values ranging up to 6 mSv/year, regular monitoring is recommended preferably on monthly basis. About the calibration of dosimeters, IRPA suggested that correction factor might be needed to take into account the difference between wearing and calibration conditions. For conservative estimates, the eye lens dosimeter should be worn as close as practicable to the eye. For homogeneous radiation exposure, an unshielded whole body dosimeter worn at chest provides good estimate of the WBD and eye lens doses, especially for photons. However, in the case of nonhomogeneous exposures, dosimeter adjacent to the eye which is closer to radiation source and faces X-ray tube (as in the case of IC/IR) should be worn.
On the use of eye protection devices, the workers should be made aware for their proper use through education and training. Eyewear containing plastic lenses is suitable for reduction of beta doses whereas for the reduction of doses from X-rays especially in IC/IR facilities, lead glass lenses are recommended. Exposure from gamma radiation that is so penetrating that the protective eyewear would be too heavy/bulky to wear and is impractical to use. In addition, the reduction in intensity will also be insignificant. These protective devices need to be worn regularly so as to practice as low as reasonably achievable (ALARA) philosophy. Similarly, ceiling suspended shields are recommended for IC/IR facilities performing X-ray-based procedures. In addition, the use of protective devices is highly recommended if the annual eye lens doses exceed 6 mSv. Typical dose reduction factor of 2–3 may be used if it is ensured that lead goggles are properly and regularly used in all radiation-specific procedures without break.
Regarding quantity of measurement for eye lens dose, it may be noted that personnel dose equivalent, Hp(3) has been recommended internationally, whereas for WBD and skin dose measurement, Hp(10) and Hp(0.07) are used. For radiation facilities where uniform and homogeneous photon fields prevail, WBD may provide conservative estimate of the Hp(3) and exceptionally Hp(0.07) may also be used with priory established correction factors. However, in these cases, IRPA suggests that the dosimeter needs to be type tested and calibrated in terms of other quantities such as Hp(10) or Hp(0.07).
Regarding the implementation of new dose limit, IRPA states that the revised dose limit has been incorporated into the IAEA Basic Safety Standards (BSS) and also into council directive the Euratom of European Union. As per the directive, the member states of the European Union should implement the new dose limit by February 2018 (The detailed report on the same can be assessed from: http://www.irpa.net)..
| II. Launch of Icrpaedia by International Commission on Radiological Protection|| |
ICRP has launched a web link ICRPaedia, a new online tool that helps persons at all levels in understanding the philosophy of ICRP and its work. This is a big step toward ICRP's priority to better engage with members, health professionals, and the general public so as to address concerns about radiation. The same may be assessed from http://www.icrp.org/icrpaedia/toc.asp.
| III. Future Meetings/symposia/conferences|| |
33rd IARP's International Conference on “Developments towards improvement of radiological surveillance at nuclear facilities and environment” (IARPIC – 2018) will be held at Mumbai during January 16–20, 2018 (visit www.iarp.org.in).
International Commission on Radiological Protection-2017
4th International Symposium on the System of Radiological Protection – ICRP 2017 will be organized at Paris, France during October 10–12, 2017.
International Radiation Protection Association congress
15th International Congress of IRPA will be organized at Seoul, South Korea during May 11–15, 2020.
Munish Kumar1 , D. D. Rao2
1Associate Editor, RPE, Radiological Physics and Advisory Division, BARC, 2Editor, RPE, Radiation Safety Systems Divisions, BARC, Mumbai, Maharashtra, India
| IV. Summary of Technical Meeting on “implementation of Requirements of Planned Exposure Situations of International Basic Safety Standards – GSR Part 3”|| |
A technical meeting on the “Implementation of Requirements of planned exposure situations of International BSS – GSR part 3” was organized by Health Safety & Environment Group (HS&EG) EG, BARC in association with the Indian Association for Radiation Protection at HPD Auditorium, CT&CRS Building during March 2–4, 2017. The participants included around 100 officers from NRB, NRG, IGCAR, KARP, PREFRE, and NPCIL sites along with the officers from HS&EG, BSC, and AERB.
BSS – GSR Part 3 provides an integrated and consistent set of safety requirements which establishes requirements that should be met to ensure the protection of people and the environment from radiation exposure both now and in the future. The requirements are governed by the objective and principles of the safety fundamentals.
The highlights of the meeting are as follows: Chairman, Atomic Energy Regulatory Board (AERB) inaugurated the meeting and Chairman, BARC Safety Council (BSC) delivered the keynote address. Director, HSEG, IGCAR and AD, HS&EG, BARC also graced the occasion and delivered lectures highlighting the importance of the technical meeting. The meeting was scheduled in four technical sessions, and various experts from DAE delivered lectures on related thematic topics on the BSS – GSR Part 3. The expert lecturers included Dr. P. C. Kesavan, M.S. Swaminathan Research Foundation (MSSRF), Chennai, Dr. Venkatesh Rangarajan, Tata Memorial Centre (TMC), Dr. C. P. Kaushik, CS, WMD, and Dr. B. S. Rao to name a few. Lectures on various topics such as LNT, justification in medical exposures, review status of implementation of BSS requirements in various exposure situations, waste management techniques, and operational radiation protection aspects of reprocessing plants and accelerators were given by respective experts from the field. The lectures were well received by the participants, numbering over 100, and effective interaction of the participants with lecturers was noticed. On March 4, a panel discussion was conducted in which several panel experts from AERB, BARC interacted with the participants on issues relating to eye lens dosimetry, radiological issues related with contractor employees, and justification of medical exposures.
Several pertinent points surfaced during the meeting and the following are a gist:
- AERB/BSC may prepare the “Status report on Assessment of the level of implementation of the BSS Part 3 requirements in Planned Exposure Situations in BARC facilities,” along with any possible constraints in the full implementation. This can be sent to IAEA and IRPA News, for their Information
- It was opined for a centralized independent national body as custodian of the radiation exposure data and to analyze the effects of radiation exposure to workers and the member of public in line with the spirit of various international recommendations. Centralized maintenance of the dose records of itinerant workers using AADHAAR numbers as the key pin number for the follow-up of exposures, including internal exposures if any. It is felt that only under such conditions, we can hold contractor responsible for the safety of the workers as suggested in one of the requirements of the BSS and the safety guide of ORP
- Although BSS are well understood, there are a number of application details that need to be worked out. In the area of accelerators, dosimetry in hundreds of MeV and GeV as we encounter in our RRCAT, Indore facilities are imprecise and is not well understood, and hence, an energy independent dosimetry system is to be strengthened
- A position paper on the status of revision of the dose limit of eye lens should be issued by AERB/BSC.
Dr. R. K. Gopalakrishnan
Convenor, BSS.GSR.2017 & Head, RHCS, RSSD, BARC, Mumbai, Maharashtra, India