International Atomic Energy Agency ASSESSMENT OF OCCUPATIONAL EXPOSURE DUE TO EXTERNAL RADIATION SOURCES AND INTAKES OF RADIONUCLIDES Dosimetry Services for Individual Monitoring

International Atomic Energy Agency Dosimetry Services – Unit Objectives The objective of this unit is to provide a review of the need for a complete dosimetry service, including information on design, implementation and management of an Individual Monitoring Service (IMS). The unit describes the full range of information elements that comprise a complete service, with recommendations on organizational structure and personnel. At the completion of the unit, the student should understand how to approach establishing or requisitioning a dosimetry service.

International Atomic Energy Agency Dosimetry Services – Unit Outline Design of a Monitoring Programme Monitoring Methods Choice of Monitoring Procedures Installation Requirements Cost Considerations Practical Operational Considerations Data Management and Record Keeping Management and Administration Quality Management

International Atomic Energy Agency Individual Monitoring Service (IMS) The main objectives of an IMS are: l To supply dosimeters and/or to apply bioassay measurements suitable for the determination of doses; l To provide results within a reasonable timescale; l To store the results in a secure record keeping system

International Atomic Energy Agency Main Parts of an IMS Dosimetry system (dosimeters, evaluation equipment; intake monitoring instruments) Administrative system (customers database, employees database, commercial arrangements) Record keeping system (doses and technical data) Calibration tools Quality management procedures

International Atomic Energy Agency Design of a Monitoring Programme

International Atomic Energy Agency Design Scheme of an Individual Monitoring Programme

International Atomic Energy Agency Need for Individual Monitoring "For any worker who is normally employed in a controlled area, or who occasionally works in a controlled area and may receive significant occupational exposure, individual monitoring shall be undertaken where appropriate, adequate and feasible” (BSS) For external exposure integrating dosimeter (with an additional self-reading dosimeter if applicable) should be used

International Atomic Energy Agency Need for Individual Monitoring – External Exposure The personnel should be provided with: Integrating dosimeter (and an additional self-reading dosimeter if applicable); Dosimeter for H p (10) and H p (0.07), as appropriate; Two (or more) dosimeters in inhomogeneous radiation fields (extremities, eye, etc.)

International Atomic Energy Agency Need for Individual Monitoring – Internal Exposure Situations where it should be considered: Handling large quantities of gaseous or volatile materials; Mining, milling and processing U, Th ores; Processing Pu and other transuranic elements; Mines and other workplaces with elevated levels of radon Producing bulk quantities of radionuclides Use of radiopharmaceuticals for therapy; Maintaining nuclear facilities.

International Atomic Energy Agency Monitoring Methods

International Atomic Energy Agency Monitoring Methods for External Exposure Film dosimetry Thermolumiscent dosimetry (TLD) Electronic personal dosimetry (EPD) Radiophotoluminescent dosimetry (RPL) Optically stimulated luminescent dosimetry (OSL) Neutron dosimetry (NTA, TLD albedo, track etch) (Details are given in Unit 5)

International Atomic Energy Agency Main characteristics of dosimeters

International Atomic Energy Agency Monitoring Methods for Internal Exposure The choice of monitoring method depends on: Radiation (type and energy) emitted by the radionuclide; Biokinetic behavior of the radionuclide; Required frequency of the measurements; Sensitivity, availability, etc. of the measurement facilities. Two basic methods are: direct and indirect (Details are given in Unit 7 and 8)

International Atomic Energy Agency Decision on the Intake Monitoring Frequency

International Atomic Energy Agency Choice of Monitoring Procedures

International Atomic Energy Agency External Radiation Factors influencing the choice of an IMS: Practice and radiation fields (see Table); Characteristics of the dosimetry systems; Availability, reliability, transportation; Cost considerations.

International Atomic Energy Agency Work Practices - External Radiation Fields

International Atomic Energy Agency Internal Exposure Factors influencing the choice of an IMS: Working practice and radionuclides used (see Table); Characteristics of the monitoring systems; Availability, reliability, transportation; Cost considerations.

International Atomic Energy Agency Work Practices – Radionuclides

International Atomic Energy Agency Installation Requirements

International Atomic Energy Agency General Requirements Scope of the service (  choice of the dosimetry system); Legal requirements (QM, approval, retention of physical evidence, etc.); Staff, infrastructure, accomodation, environmental conditions (background!); Maintenance, safety and security.

International Atomic Energy Agency Cost Considerations

International Atomic Energy Agency Cost for establishing an IMS Equipment cost: u Dosimeters, u Evaluation unit, u In vivo monitoring instrument, u Radiochemical laboratory, u In vitro measurement instruments, u Calibration facility. l Maintenance cost l Staff cost l Cost of consumables, postage, etc.

International Atomic Energy Agency Practical Operational Considerations

International Atomic Energy Agency External Dosimetry Handling and processing of dosimeters (ability to handle anomalies – lost, damaged, contaminated, etc. dosimeters) Calibration Degree of automation Assistance to the dosimeter wearers: u Wear your dosimeter under work, u Store it right place (background, temperature, humidity, etc.) u Do not lose and damage it. l Dose report content and approval

International Atomic Energy Agency Internal Dosimetry Calibration Direct monitoring methods: u Removal of external contamination, u Choice of the appropriate measuring geometry. Indirect monitoring methods: u Labeling of samples, u Prevention of contamination, u Considering biological hazard. l Interpretation of measurement results (intake, dose) l Dose report content and approval

International Atomic Energy Agency Data Management and Record Keeping

International Atomic Energy Agency Dosimetry records l Information to identify the worker. l Measurements of external dose u Personal dose equivalent, H P (10) u Personal dose equivalent, H P (0.07) l Measurements of internal dose, such as Committed Effective Dose.

International Atomic Energy Agency Measurement techniques l Date, time and duration of measurement l Dosimeters used l Detector(s), measurement geometry, shielding l Calibration l Method of the data analysis l Detection limits for doses and radionuclides of interest (and for 40 K)

International Atomic Energy Agency Measurement results l External exposure: u H p (10); H p (0.07) u Extremity monitoring u Estimate of radiation quality Internal exposure: t Committed effective doses to all radionuclides t Activities of all radionuclides together with the uncertainties t For null results, detection thresholds calculated from the measurement of the subject

International Atomic Energy Agency Management and Administration

International Atomic Energy Agency General Considerations Details on management, organization and administration depend on: Number of dosimeters, measurements; Number of customers; Type of dosimeters, monitoring methods used; Level of automation; Flexibility (e.g. monitoring periods)

International Atomic Energy Agency Organization Main elements: Routine monitoring: u Laboratory, u Calibration, u Workshop. l Record keeping l Administration and finances: u Mailing center, u Customer relations u Quality management.

International Atomic Energy Agency Personnel Head of Service Main (+1 deputy) Dosimeter preparation, dispatch (2) l Sample collection, receipt (2) l Dosimeter processing (2) l Sample processing (2) l In vivo, in vitro measurements (2) l Dose assessment (2) l Record keeping (2) l Administration (1) l Maintenance (1) l Quality manager (1)

International Atomic Energy Agency Quality Management

International Atomic Energy Agency Main components of the Quality Management l Two main components of the quality management (ISO9000:2000):  quality assurance (QA) and  quality control (QC) l QA is an interdisciplinary management tool that provides a means for ensuring that all work is adequately planned, correctly performed and assessed; l QC is a means of applying controls to the process to ensure that the product or service consistently meets specifications. (More details are given in Unit 15)

International Atomic Energy Agency References FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS, INTERNATIONAL ATOMIC ENERGY AGENCY, INTERNATIONAL LABOUR ORGANISATION, OECD NUCLEAR ENERGY AGENCY, PAN AMERICAN HEALTH ORGANIZATION, WORLD HEALTH ORGANIZATION, International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources, Safety Series No. 115, IAEA, Vienna (1996). INTERNATIONAL ATOMIC ENERGY AGENCY, Occupational Radiation Protection, Safety Guide No. RS-G-1.1, ISBN (1999). INTERNATIONAL ATOMIC ENERGY AGENCY, Assessment of Occupational Exposure Due to Intakes of Radionuclides, Safety Guide No. RS-G-1.2, ISBN (1999). INTERNATIONAL ATOMIC ENERGY AGENCY, Indirect Methods for Assessing Intakes of Radionuclides Causing Occupational Exposure, Safety Guide, Safety Reports Series No. 18, ISBN (2002). INTERNATIONAL ATOMIC ENERGY AGENCY, Direct Methods for Measuring Radionuclides in the Human Body, Safety Series No. 114, IAEA, Vienna (1996). INTERNATIONAL COMMISSION ON RADIATION UNITS AND MEASUREMENTS, Direct Determination of the Body Content Of Radionuclides, ICRU Report 69, Journal of the ICRU Volume 3, No 1, (2003). INTERNATIONAL ATOMIC ENERGY AGENCY, Assessment of Occupational Exposure Due to External Sources of Radiation, Safety Guide RS-G-1.3 (1999). INTERNATIONAL COMMISSION ON RADIOLOGICAL PROTECTION, General Principles for the Radiation Protection of Workers, Publication No. 75, Pergamon Press, Oxford and New York (1997).