International Atomic Energy Agency Individual Dose Assessment ASSESSMENT OF OCCUPATIONAL EXPOSURE DUE TO INTAKE OF RADIONUCLIDES.

International Atomic Energy Agency Individual Dose Assessment ASSESSMENT OF OCCUPATIONAL EXPOSURE DUE TO INTAKE OF RADIONUCLIDES

International Atomic Energy Agency Individual Dose Assessment – Unit Objectives The objective of this unit is to provide an overview of the use monitoring measurement to assess the exposure from internally deposited radionuclides. It includes a discussion of the use of material and individual specific data to improve dose estimates, and the role of task and special monitoring in assessment of internal exposure. At the completion of the unit, the student should understand the principles involved in dose assessment, and how to apply these principles.

International Atomic Energy Agency Individual Dose Assessment – Unit Outline l Introduction l Need for Monitoring l Routine Monitoring Programme Design l Methods of Measurement l Monitoring Frequency l Reference Levels l Use of Material & Individual Specific Data l Task Related Monitoring l Special Monitoring

International Atomic Energy Agency Introduction

Monitoring objective The general objective of operational monitoring programmes is the assessment of workplace conditions and individual exposures The assessment of doses to workers routinely or potentially exposed to radiation through intakes of radioactive material constitutes an integral part of any radiation protection programme and helps to ensure acceptably safe and satisfactory radiological conditions in the workplace

International Atomic Energy Agency Individual monitoring methods Individual monitoring for intakes is done by: Direct methods u Whole body counting u Organ counting (e.g. thyroid or lung monitoring) Indirect methods u Analysis of samples of excreta u Analysis of selected body fluids or tissues u Personal air samplers is also used

International Atomic Energy Agency Workplace monitoring Workplace monitoring is used in many situations involving radionuclide exposure May be used to demonstrate satisfactory working conditions or where individual monitoring may not be sufficient May be appropriate when contamination levels are low, for example in a research laboratory using small quantities of radioactive tracers

International Atomic Energy Agency Monitoring techniques for internal dose estimation Monitoring for radionuclide intake dose estimation may include one or more techniques: Sequential measurement of radionuclides in the whole body or in specific organs; Measurement of radionuclides in biological samples such as excreta or breath; Measurement of radionuclides in physical samples such as filters from personal or fixed air samplers, or surface smears.

International Atomic Energy Agency Determination of committed effective dose Measurements are used to determine intake The intake, multiplied by the dose coefficient, gives an estimate of committed effective dose Dose coefficients have been calculated by the ICRP and are given in the BSS In some situations, direct measurements may be used to determine whole body or individual organ dose rates directly

International Atomic Energy Agency AMAD (activity median aerodynamic diameter) The aerodynamic diameter of an airborne particle is the diameter that a sphere of unit density would need to have in order to have the same terminal velocity when settling in air as the particle of interest. The thermodynamic diameter is the diameter that a sphere of unit density would need to have in order to have the same diffusion coefficient in air as the particle of interest.

International Atomic Energy Agency DOSE COEFFICIENTS FOR SELECTED RADIONUCLIDES Radionuclide InhalationIngestion Type /form (a) e(g)inh (Sv/Bq) f1e(g)ing (Sv/Bq) AMAD = 1μmAMAD = 5μm H-3HTO (c)1.8 E-11(b)11.8 E-11 OBT4.1 E-11(b)14.2 E-11 Gas1.8 E-15(b) C-14Vapour5.8 E-10(b)15.8 E-10 CO 2 6.2 E-12(b) CO8.0 E-13(b) P-32F8.0 E-101.1 E-090.82.3 E-10 M3.2 E-092.9 E-09 Fe-55F7.7 E-109.2 E-100.13.3 E-10 M3.7 E-103.3 E-10 Fe-59F2.2 E-093.0 E-090.11.8 E-09 M3.5 E-093.2 E-09 Co-60M9.6 E-097.1 E-090.13.4 E-09 S2.9 E-081.7 E-080.052.5 E-09 Sr-85F3.9 E-105.6 E-100.35.6 E-10 S7.7 E-106.4 E-100.013.3 E-10

International Atomic Energy Agency Need for Monitoring

International Atomic Energy Agency Designation of workplace areas Determination of the need for monitoring begins with designation of workplace areas u Supervised areas u Controlled areas Area designation is based on knowledge of workplace conditions and the potential for worker exposure

International Atomic Energy Agency Designation of workplace areas A worker should be enrolled in an internal exposure monitoring programme when there is a likelihood of an intake that exceeds a predetermined level Guidance on the designation of areas is given in the Guide on Occupational Exposure If operational procedures are set up to prevent or reduce the possibility of intake, a controlled area will, in general, need to be established

International Atomic Energy Agency Establishing the need for monitoring Individual or area monitoring need depends on: Amount of radioactive material present Radionuclide(s) involved Physical and chemical form Type of containment used Operations performed and General working conditions

International Atomic Energy Agency Establishing the need for monitoring Examples: Workers handling sealed sources, or unsealed sources in reliable containment, may need to be monitored for external exposure, but not necessarily for internal exposure Workers handling radionuclides such as tritium, I-125 or Pu-239 may need monitoring for internal exposure, but not for external exposure

International Atomic Energy Agency To monitor or not to monitor? The decision to conduct intake monitoring may not be simple Routine monitoring only for: u Workers in controlled areas u Contamination control and u When significant intakes can be expected From experience, if a C.E.D. > 1 mSv is unlikely, u Individual monitoring may be unnecessary u Workplace monitoring may be in order

International Atomic Energy Agency Situations that may call for monitoring Some situations where routine individual monitoring may be appropriate include: Handling of large quantities of gaseous or volatile materials, e.g. 3 H and its compounds in; u Large scale production processes u Heavy water reactors and u Luminizing; Processing of plutonium and other transuranic elements;

International Atomic Energy Agency Situations that may call for monitoring Mining, milling and processing of thorium ores Use of thorium and its compounds – can lead to exposure from radioactive dusts, and thoron (Rn-220) and its progeny); Mining, milling and refining of high grade uranium ores; Processing of natural and slightly enriched uranium, and reactor fuel fabrication;

International Atomic Energy Agency Situations that may call for monitoring Bulk production of radioisotopes; Working in mines and other workplaces where radon levels exceed a specified action level; Handling radiopharmaceuticals, such as I-131 for therapy, in large quantities; Reactor maintenance  exposure due to fission and activation products

International Atomic Energy Agency Individual vs. Workplace monitoring Individual monitoring may not be feasible for some radionuclides because of: u Radiation type(s) emitted and u Detection sensitivity of monitoring methods In such situations, reliance must be placed on workplace monitoring However, for some radionuclides, e.g. 3 H, individual monitoring may be more sensitive than workplace monitoring

International Atomic Energy Agency Monitoring for new operations Individual monitoring is likely to be needed for new operations As experience in the workplace is accumulated, the need for routine individual monitoring should be kept under review Workplace monitoring may be found to be sufficient for radiological protection purposes

International Atomic Energy Agency Routine Monitoring Programme Design

International Atomic Energy Agency Consider monitoring limitations Monitoring conducted on a fixed schedule for selected workers is routine monitoring Internal exposure monitoring has several limitations These limitations should be considered in the design of an adequate monitoring programme Monitoring does not measure directly the committed effective dose to the individual

International Atomic Energy Agency Internal exposure monitoring limitations l Monitoring does not measure directly the committed effective dose to the individual l Biokinetic models are needed to: u determine activity in the body from excreta sample activity levels, u determine intake from body content, u calculate the committed effective dose from the estimated intake

International Atomic Energy Agency Further internal monitoring limitations Measurements may be subject to interference from other radionuclides present in the body: Natural 40 K present naturally Cs-137 from global fallout Uranium naturally present in the diet Radiopharmaceuticals administered for diagnostic or therapeutic purposes

International Atomic Energy Agency Interference from “background” radionuclides Establish the radionuclide body content from previous intakes Particularly important when the non- occupational intakes are elevated, e.g. in mining areas high domestic radon exposure Workers should have bioassay measurements before working with radioactive materials to establish a ‘background’ level.

International Atomic Energy Agency Interference from Radiopharmaceuticals Radiopharmaceuticals can interfere with bioassays for some time after administration Duration of interference depends on: u Properties of the agent administered and u Radionuclides present at the workplace Request workers to report administration of radiopharmaceuticals It can then be determined if adequate internal monitoring can be performed

International Atomic Energy Agency Internal exposure monitoring limitations l The results of an individual monitoring programme for the estimation of chronic intakes might depend on the time at which the monitoring is performed l For certain radionuclides with a significant early clearance component of excretion, there may be a significant difference between measurements taken before and after the weekend

International Atomic Energy Agency Internal exposure monitoring limitations l For nuclides with long effective half-lives, the amount present in the body and the amount excreted depend on, and will increase with, the number of years for which the worker has been exposed l In general, the retained activity from previous years’ intakes should be taken to be part of the background for the current year

International Atomic Energy Agency Timing of measurements is important Results for the estimation of chronic intakes can depend on when the monitoring is done If radionuclides have a significant early clearance, difference between pre- and post- weekend measurements may be significant These should be reviewed individually if chronic exposure is possible

International Atomic Energy Agency Timing of measurements is important If nuclides have long effective half-lives, u Amount present in the body and u Amount excreted depend on the number of years for which the worker has been exposed These amounts may increase with exposure Retained activity from previous years’ intakes should generally be taken to be part of the background for the current year

International Atomic Energy Agency Internal exposure monitoring limitations The analytical methods used for individual monitoring sometimes do not have adequate sensitivity to detect the activity levels of interest

International Atomic Energy Agency Air and surface monitoring Analytical methods may not have adequate sensitivity A system of workplace and personnel monitoring may be needed to determine radionuclide intake quantities Fixed or personal air samplers (PASs) may be used to determine the airborne concentrations of radioactive material

International Atomic Energy Agency Air and surface monitoring Air sampling results, together with standard or site specific assumptions: u Physical and chemical form of the material u Breathing rate and u Worker exposure time to estimate inhalation intakes Surface monitoring may also indicate intake potential or need for detailed area monitoring But, models for estimating intake from surface contamination are particularly uncertain

International Atomic Energy Agency Methods of Measurement

International Atomic Energy Agency Direct vs. Indirect measurements Radionuclide intake can be determined by either direct or indirect measurement methods Direct measurement of photons is also referred to as body activity measurements, whole body monitoring or whole body counting Indirect measurements include activity in either biological or physical samples Each type has advantages and disadvantages The selection of over than another depends on the nature of the radiation to be measured

International Atomic Energy Agency Direct measurements Direct methods are useful only for those radionuclides which emit photons: u Of sufficient energy, and u In sufficient numbers, u To escape from the body and u Be measured by an external detector Direct measurements are particularly useful for fission and activation products

International Atomic Energy Agency Direct measurements Radionuclides which do not emit energetic photons (e.g. 3 H, 14 C, 90 Sr- 90 Y) can usually be measured only by indirect methods Pu-239 emits weak x-rays and may be measured by either method Some higher energy beta emitters, e.g. 32 P or 90 Sr -90 Y, can sometimes be measured ‘directly’ via the bremsstrahlung produced These measurements have a relatively high minimum detectable activities and are not usually employed for routine monitoring

International Atomic Energy Agency Direct measurements Direct measurements: u Rapid u Convenient u Can estimate activity in the whole body or a defined part of the body u Less dependent on biokinetic models than indirect monitoring

International Atomic Energy Agency Direct measurements May have greater calibration uncertainties, especially for low energy photon emitters May require the worker to be removed from work involving radiation exposure for the period over which the retention characteristics are measured Often need special, well shielded, and expensive facilities and equipment.

International Atomic Energy Agency Direct measurements – Qualitative applications Useful in qualitative and quantitative determinations of radionuclides Can assist in identifying the mode of intake by determining the distribution of activity Sequential measurements can reveal activity redistribution and give information about the total body retention and biokinetics

International Atomic Energy Agency Indirect measurements Generally interfere less with workers duties However, require access to a radiochemical analytical laboratory Analytical laboratory may also be used for measuring environmental samples Perform high level (e.g. reactor water chemistry) and low level (e.g. bioassay or environmental samples) work in separate laboratories

International Atomic Energy Agency Indirect measurements - Excreta Excreta measurements determine the rate of loss of radioactive materials from the body by a particular route Must be related to body content and intake by a biokinetic model Radiochemical analyses  low detection levels  sensitive detection of body activity

International Atomic Energy Agency Indirect measurements – Air samples Can be difficult to interpret - air concentration may not represent breathing zone Personal air sampler (PAS) placed on the worker’s lapel or protective headgear can collect more representative samples Sample comprising only a few particles still a problem Air concentrations + breathing rates + measured exposure times = estimated intake

International Atomic Energy Agency Indirect measurements – Air samples Use of PASs only estimates intake Cannot be used to refine a dose estimate based on individual retention characteristics PAS measurements cannot be repeated Can provide intake estimates for nuclides such as 14 C (particulate), 239 Pu, 232 Th and 235 U, when other methods may have sufficient sensitivity Interpretation depends on the dose coefficients and the derived air concentration (DACs)

International Atomic Energy Agency Particles size is important Particle size influences deposition of inhaled particulates in the respiratory tract Correct interpretation of bioassay and dose assessment depends on particle size data Determine airborne particle size distribution using cascade impactors or other methods BB bb Al ET 2 0.1110100 AMAD (  m) 100 10 1 0.1 0.01 Regional deposition (%) ET 1

International Atomic Energy Agency Particles size is important Measurements should, at least, include the concentration of the respirable fraction Some models for interpreting PAS results discriminate against non-respirable particles Dose assessment improves with more site and material specific information

International Atomic Energy Agency Measurement detection limits Measurement methods have limits of detection arising from: u Naturally occurring radioactive materials u Statistical fluctuations in counting rates, and u Factors related to sample preparation and analysis Minimum significant activity (MSA) and minimum detectable activity (MDA)will be discussed in another unit

International Atomic Energy Agency Monitoring Frequency

International Atomic Energy Agency Individual monitoring frequency BSS: “The nature, frequency and precision of individual monitoring shall be determined with consideration of the magnitude and possible fluctuations of exposure levels and the likelihood and magnitude of potential exposures.” Characterize the workplace to determine the appropriate frequency and type of monitoring!

International Atomic Energy Agency Individual monitoring frequency Identify radionuclides in use and determine their chemical and physical forms Consider possible changes of these forms under accident conditions; e.g. the release of uranium hexafluoride into the atmosphere results in the production of HF and uranyl fluoride

International Atomic Energy Agency Individual monitoring frequency Chemical and physical forms (e.g. particle size) determine material behaviour on intake and biokinetics in the body These in turn determine the excretion routes and rates, and hence the type of excreta samples to be collected and their frequency

International Atomic Energy Agency Proper frequency minimizes intake uncertainty Set bioassay sampling schedules to minimize intake estimate uncertainties due to the unknown time of an intake, i.e. u If acute intake occurs immediately after previous assay, u Assuming intake at the monitoring period midpoint underestimates the intake Monitoring period should be short enough that the underestimate  factor of 3

International Atomic Energy Agency Determining the monitoring frequency Monitoring period, ΔT, depends on: Radionuclide retention, R(t) Radionuclide clearance, E(t) Sensitivity of the measurement process, i.e measurement MDA Acceptable uncertainty Committed effective dose, e(50)

International Atomic Energy Agency Determining the monitoring frequency For in vivo measurements e(50)  MDA/R(ΔT)  365/ΔT ≤ 1 mSv/year For in vitro measurements e(50)  MDA/E(ΔT)  365/ΔT ≤ 1 mSv/year Maximum overestimation shouldn’t exceed 3  If exposure occurs at ΔT/2, this means; R(1)/R(ΔT/2) ≤ 3 E(1)/E(ΔT/2) ≤ 3

International Atomic Energy Agency Recommended maximum time intervals for routine monitoring

International Atomic Energy Agency Suggested maximum time intervals for routine monitoring for uranium compounds

International Atomic Energy Agency Suggested maximum time intervals for routine monitoring for actinide compounds

International Atomic Energy Agency Recommended monitoring interval tolerances Unreasonable to expect bioassay measurements to be preformed on exact schedule Monitoring interval - DaysTolerance - Days 15  2 30  4 60  7 90  14 180  30 365  30

International Atomic Energy Agency Schedule to avoid missing an intake Schedule monitoring to ensure an intake above a predetermined level is not ‘missed’ Intake could be missed if, u As a result of clearance, u Body content or daily excretion u Declines to a level below the minimum significant activity of the measurement u During the time between intake and measurement

International Atomic Energy Agency Schedule to avoid missing an intake m(t) - Fraction of an intake in the body (direct measurement) or being excreted from the body for indirect measurement, depends on: Physical half-life Biokinetics of the radionuclide, and Is a function of the time since intake

International Atomic Energy Agency Schedule to avoid missing an intake An intake I and the resulting committed effective dose E(50) would be missed if, I  m(t) is less than the MSA Monitoring frequency should be set so that intakes corresponding to more than 5% of the annual dose limit are not missed.

International Atomic Energy Agency Monitoring frequency depends on sensitivity Monitoring frequency is largely driven by the sensitivity of the measurement technique Measurement techniques should be as sensitive as possible However, associated costs - u Most sensitive techniques u Frequent monitoring measurements should be balanced against risk doses are underestimated or missed

International Atomic Energy Agency Additional methods for better sensitivity Measurement method and frequency should detect intakes  a specified dose limit fraction Goal cannot be realized because: u Lack of analytical sensitivity u Unacceptably long counting times u Short sampling intervals required for excreta collection Additional methods – e.g. improved workplace monitoring and personal air sampling - should be used for adequate worker protection

International Atomic Energy Agency Use of Reference Levels

International Atomic Energy Agency Reference levels Reference levels are helpful in management of operations Expressed in terms of measured quantities or other quantities to which measured quantities can be related If exceeded, take specified action or decision Reference levels usually based on committed effective dose E(50) for radionuclide intake

International Atomic Energy Agency Reference levels Appropriate dose limit fraction corresponding to each reference level should be established Take other sources of exposure into account Recording Levels and Investigation Levels relevant to internal contamination monitoring for occupational exposures.

International Atomic Energy Agency Recording level Defined as “a level of dose, exposure or intake specified by the regulatory authority at or above which values of dose, exposure or intake received by workers are to be entered in their individual exposure records” Example - RL for a radionuclide intake set to correspond to a committed effective dose of 1 mSv (0.001 Sv) from a year’s intakes

International Atomic Energy Agency Recording level For N monitoring periods per year, the recording level for intake of radionuclide j in a monitoring period would be given by:

International Atomic Energy Agency Investigation level Is “the value of a quantity such as effective dose, intake or contamination per unit area or volume at or above which an investigation should be conducted” Investigation level for radionuclide intake - A value of committed effective dose above which monitoring results justify further investigation Set by management, depends on programme objectives and type of investigation to be done

International Atomic Energy Agency Investigation level For routine monitoring, the investigation level for a radionuclide intake is set in relation to: u Type and frequency of monitoring u Expected level and variability of intakes Numerical value of the investigation level depends on conditions in the workplace Investigation level may be set for; u Individuals in a particular operation, or u Individuals within a workplace without reference to a particular operation

International Atomic Energy Agency Investigation level – An example Routine operation with routine monitoring IL set at a committed effective dose of 5 mSv (0.005 Sv) from a year’s intakes For N monitoring periods per year, the IL (in Bq) for the intake of any radionuclide j in any monitoring period is: where e(g) j is the dose coefficient for inhalation or ingestion

International Atomic Energy Agency Derived levels Measured quantities are radionuclide activities in the body or excreta samples It is convenient to establish reference levels for the measurement results themselves These are termed derived investigation levels (DILs) and derived recording levels (DRLs) Measurement results that imply radionuclide intakes or committed effective doses at the corresponding reference levels

International Atomic Energy Agency Derived levels Derived investigation and recording levels are calculated separately for each radionuclide Specific to the radiochemical form in the workplace Are a function of time since intake For the previous examples,

International Atomic Energy Agency Derived recording level t 0 (time elapsed between intake and bioassay) is usually set as 365/2N days - assumes that intake occurs at the mid-point of the monitoring period, and

International Atomic Energy Agency Derived levels Measurement result should always be maintained in the radiation monitoring records for the workplace and for the individual For worker exposure to external radiation or to multiple radionuclides, management may need to reduce the derived levels for individual radionuclides appropriately.

International Atomic Energy Agency Use of Material and Individual Specific Data

International Atomic Energy Agency Biokinetic models Biokinetic models for most radionuclides u Developed by the ICRP u Use reference parameter values u Are based on Reference Man data, and u Observed radionuclide behaviour in humans and animals Have been developed for defined chemical forms of radionuclides, and Are generally used for planning purposes

International Atomic Energy Agency Biokinetic models Characterize particular workplace conditions to determine forms actually present In some circumstances, the chemical or physical forms of the radionuclides will not correspond to the reference biokinetic models Then, material specific models may need to be developed

International Atomic Energy Agency Specific biokinetic models For small intakes are small, i.e. a few per cent of the dose limit, reference models are probably good enough If the intake estimate  1/4 dose limit, model parameters for; Specific material(s), and Individual(s) may be needed for better estimate of the committed effective dose

International Atomic Energy Agency Specific biokinetic models Specific models can be developed from sequential direct and indirect measurements of the exposed workers Analysis of workplace air and surface contamination samples can also assist in the interpretation of bioassay measurements Example - Measure 241 Am/ 239,240 Pu from direct lung measurement of 241 Am to assess plutonium intakes or inhaled particle solubility

International Atomic Energy Agency Need for specific information Common example – aerosol particle size a worker would likely inhale differs significantly from ICRP 5 μm AMAD default value Fractions of inhaled materials deposited in various regions of the respiratory tract would have to be determined from the ICRP respiratory tract model, and An appropriate dose coefficient calculated

International Atomic Energy Agency Need for specific information More specific information may also be needed on the material solubility characteristics Can be obtained from experimental studies in animals or by in vitro solubility studies Retrospective determination of particle characteristics may be difficult Consideration should be given to obtaining material specific information when setting up worker monitoring programmes

International Atomic Energy Agency Individual variability There are differences between individuals in excretion rates and other biokinetic parameters for the same intake Individual variability may be more significant than the differences between generic and individual specific biokinetic models Excreta sample collection periods should be sufficiently long to reduce this variability, e.g. 24 hours for urine and 72 hours for faeces Use of individual specific model parameters should be rare under routine circumstances.

International Atomic Energy Agency Task Related Monitoring

International Atomic Energy Agency Task related monitoring is, Not routine, i.e. it is not regularly scheduled Conducted to provide information about a particular operation, and give a basis for decisions on the conduct of the operation Useful when short term procedure conditions would be unsatisfactory for long term use Usually conducted the same as routine monitoring, unless the circumstances of the operation dictate otherwise

International Atomic Energy Agency Special Monitoring

International Atomic Energy Agency Special monitoring May be necessary as a result of; u Known or suspected exposures u An unusual incident, e.g. loss of containment of radioactive materials as indicated by an air or surface sample, or u Following an accident

International Atomic Energy Agency Special monitoring Usually prompted by a result of a routine bioassay measurement that exceeds the derived investigation level It may also result from occasional samples such as nose blows, swipes or other monitoring.

International Atomic Energy Agency Special monitoring Measurement techniques for special monitoring usually the same as routine measurement However, improved sensitivity or a faster processing time may be needed Advise the laboratory that the sample analysis or the direct measurement has priority over routine measurements, and

International Atomic Energy Agency Recommended methods for special monitoring after inhalation Legend** Recommended* Supplementary NB: Nose blow EA: Expired air WB: Whole body Th: Thyroid

International Atomic Energy Agency Recommended methods for special monitoring after inhalation

International Atomic Energy Agency Recommended methods for special monitoring after inhalation LegendNB: Nose blowEA: Expired air

International Atomic Energy Agency Special monitoring The frequency of follow-up monitoring may be changed Inform the laboratory that samples may have a higher than normal level of activity The measurement technique can be tailored to the special monitoring situation, and Necessary precautions may be taken to prevent contamination of other samples

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 92-0-102299-9 (1999). INTERNATIONAL ATOMIC ENERGY AGENCY, Assessment of Occupational Exposure Due to Intakes of Radionuclides, Safety Guide No. RS-G-1.2, ISBN 92-0-101999-8 (1999). INTERNATIONAL ATOMIC ENERGY AGENCY, Direct Methods for Measuring Radionuclides in the Human Body, Safety Series No. 114, IAEA, Vienna (1996). INTERNATIONAL ATOMIC ENERGY AGENCY, Indirect Methods for Assessing Intakes of Radionuclides Causing Occupational Exposure, Safety Guide, Safety Reports Series No. 18, ISBN 92- 0-100600-4 (2000). 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 COMMISSION ON RADIOLOGICAL PROTECTION, Individual Monitoring for Internal Exposure of Workers: Replacement of ICRP Publication 54, ICRP Publication 78, Annals of the ICRP 27(3-4), Pergamon Press, Oxford (1997).

International Atomic Energy Agency Individual Dose Assessment ASSESSMENT OF OCCUPATIONAL EXPOSURE DUE TO INTAKE OF RADIONUCLIDES.

Similar presentations

Presentation on theme: "International Atomic Energy Agency Individual Dose Assessment ASSESSMENT OF OCCUPATIONAL EXPOSURE DUE TO INTAKE OF RADIONUCLIDES."— Presentation transcript:

Similar presentations

About project

Feedback

Log in

Auth with social network:

International Atomic Energy Agency Individual Dose Assessment ASSESSMENT OF OCCUPATIONAL EXPOSURE DUE TO INTAKE OF RADIONUCLIDES.

Similar presentations

Presentation on theme: "International Atomic Energy Agency Individual Dose Assessment ASSESSMENT OF OCCUPATIONAL EXPOSURE DUE TO INTAKE OF RADIONUCLIDES."— Presentation transcript:

Similar presentations

About project

Feedback