IAEA International Atomic Energy Agency PGEC Part VI Planned Exposure Situations - Generic...
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Transcript of IAEA International Atomic Energy Agency PGEC Part VI Planned Exposure Situations - Generic...
IAEAInternational Atomic Energy Agency
PGEC Part VI Planned Exposure Situations - Generic Requirements
Module VI.2
Requirements for occupational
exposure in planned exposure situations
Postgraduate Educational Course in radiation protection and the Safety of Radiation sources
IAEA
This module will discuss the BSS generic This module will discuss the BSS generic requirements for occupational exposure in planned requirements for occupational exposure in planned exposure situations: exposure situations:
Scope of the requirements
Requirements and Responsibilities of the relevant parties, specific to occupational exposure:
Radiation protection programme
Assessment of the occupational exposure and health surveillance of workers
Education and training
Special arrangements for workers
Overview of Module VI.1Overview of Module VI.1
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Introduction
PlannedPlanned exposure situations involve the deliberate exposure situations involve the deliberate introduction and operation of sources. Planned introduction and operation of sources. Planned exposure situations may give rise normal exposures & exposure situations may give rise normal exposures & potential exposurespotential exposures
PlannedPlanned exposure situations may be sub-divided into:exposure situations may be sub-divided into:• Occupational ExposureOccupational Exposure• Public ExposurePublic Exposure• Medical ExposureMedical Exposure
This module discusses Planned Exposure Situations - Occupational Exposure Occupational Exposure
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Scope
The BSS requirements in respect of occupational exposure in planned exposure situations apply to occupational exposure due to• a practice or a source within a practice, • emergency exposure situations (as required in Section 4 of
the BSS)• existing exposure situations (as required in Section 5 of the
BSS) . Exposure due to natural sources - as shown in next slide
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occupational exposure includes the following
Exposure due to material in any relevant practice where the activity concentration in the material of any radionuclide in the uranium or thorium decay chains is greater than 1 Bq/g or the activity concentration of 40K is greater than 10 Bq/g;
Exposure due to 222Rn and its progeny and 220Rn and its progeny in workplaces in which occupational exposure due to other radionuclides in the uranium or thorium decay chains is controlled as a planned exposure situation;
Exposure due to 222Rn and 222Rn progeny where the annual average activity concentration of 222Rn in air in the workplace remains above the appropriate reference level (not exceeding 1000 Bq/m3) after activity concentrations of 222Rn in workplaces have been made are as low as reasonably achievable below the reference level and protection optimized
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Requirement 19: Responsibilities of the regulatory body specific to occupational exposure
The government or regulatory body shall establish and enforce requirements to ensure that protection and safety is optimized, and the regulatory body shall enforce compliance with dose limits for occupational exposure.
Establish the responsibilities of employers, registrants and licensees with regard to application of the requirements for occupational exposure in planned exposure situations.
Review, before authorization, supporting documents from the responsible parties regarding design aspects relating to the exposure and potential exposure of workers; and design of systems and programmes for monitoring of workers for occupational exposure
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Requirement 20: Requirements for monitoring and recording of occupational exposure
The regulatory body shall establish and enforce requirements for the monitoring and recording of occupational exposures in planned exposure situations
The regulatory body shall be responsible, as appropriate, for:
Establishment and enforcement of requirements for the monitoring, recording and control of occupational exposures
Review of monitoring programmes of registrants and licensees,
Authorization or approval of service providers for individual monitoring and calibration services;
Review of periodic reports on occupational exposure submitted by employers, registrants and licensees;
Provision for maintaining exposure records and results of the assessment of doses from occupational exposure;
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Requirement 21: Responsibilities of employers, registrants and licensees for the protection of workers
Employers, registrants and licensees shall be responsible for the protection of workers against occupational exposure. Employers, registrants and licensees shall ensure that protection and safety is optimized and that the dose limits for occupational exposure are not exceeded.
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Safety Fundamental Principle 1: Responsibility for safety “The prime responsibility for safety The prime responsibility for safety must rest with the person or must rest with the person or organization responsible for facilities organization responsible for facilities and activities that give rise to radiation and activities that give rise to radiation risksrisks.”
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Requirement 22: Compliance by workers
Workers shall fulfil their obligations and carry out their duties for protection and safety
Workers should not knowingly expose themselves, or any other person, to ionising radiation to an extent greater than is reasonably necessary for the purposes of their work.
Workers should exercise reasonable care while carrying out their work, including complying with Local Rules
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Requirement 23: Cooperation between employers and registrants and licensees
Employers and registrants and licensees shall cooperate to the extent necessary for compliance by all responsible parties with the requirements for protection and safety
If workers employer is not in control of a radiation source, then the registrant or licensee responsible for that source and the employer have to cooperate to the extent necessary for compliance by both parties with the BSS requirements
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Requirement 24: Arrangements under the 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.
The first step towards defining an RPP is to perform a prior radiological evaluation of the practice or installation - both normal and potential exposures.
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Radiation protection programme
Should be commensurate with of the type of installation concerned (ranging from ‘simple’ ones such as a dental x-ray to much more complex ones such as nuclear facilities).
May relate to all phases of a practice (design to decommissioning) but usually emphasis given to operational aspects.
Should always include protection workers, and may well need to cover protection of the public as well.
Has to cover:• Classification of areas: controlled areas & supervised areas• Local rules and procedures and personal protective equipment• Monitoring of the workplace
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Classification of areas
Controlled areas• areas requiring specific measures
for controlling normal exposures, preventing spread of contamination or preventing potential exposures
Supervised areas• areas where exposure conditions
need to be kept under review
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Classification of areas
Registrants and licensees have to formally designate workplaces as ‘Controlled Area’ or ‘Supervised Area'
Account has to be taken of the magnitudes of the exposures expected in normal operation, the likelihood and magnitude of exposures in anticipated operational occurrences and in accident conditions, and the type and extent of the procedures required for protection and safety.
account could also be taken of operational experience in relation to potential for internal and external exposures, and potential for spread of contamination
area designation may be made at the facility design stage
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Requirements for areascontrolled supervisedarea area
Local rules:
Protective clothing if in local rules
Delineate :
Display trefoil symbol not necessary
Approved signs:
Access restriction: not necessary
Dosimetry: not necessary
Monitoring:
Periodic Review
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Occupational Exposure Protection
Local rules should include:name of person(s) responsible for supervising the workdescription of controlled and supervised areasgeneral radiation safety measures, and written rules and
procedures ensuring safety investigation levels and procedures to follow if they are
exceeded information to workers on the health risks female workers / pregnancy information, instructions and training concerning
emergencies
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Personal protective equipment
Personal protective equipment (PPE)• protection and safety during normal operations should not be
based on personal protective equipment (engineered features or administrative controls are preferred)
• Where PPE is appropriate, adequate and suitable PPE has to be made available by employers, registrants and licensees
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PPE includes:Protective clothing;Respiratory protective equipment Protective aprons, protective gloves and eye shields;
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protective gloves
Gloves are often an important part of personal protection.
Workers should check to ensure the absence of cracks or small holes in the gloves before each use.
In order to prevent the unintentional spread of contamination, gloves should be removed before leaving the work area and before handling such things as telephones, doorknobs, etc
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Monitoring of the workplace
workplace monitoring has to be under the supervision of a radiation protection officer or qualified expert
The RPO or QE needs to consider; o Measurement methods and procedures
o Quantities to be measured
o Place and time-scale of measurements
o Reference levels and actions if exceeded
Purpose of monitoring:Evaluation of the radiological conditions in all workplaces;Assessment of exposures in controlled areas and supervised areas;Review of the classification of controlled areas and supervised areas;
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Neutron survey
Electronic dosimeter
Gamma surveyContamination survey
Typical workplace monitoring instruments
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workplace monitoring records
It is good practice to:
Record results in a dedicated monitoring log.
Indicate the location, date, name of person performing the survey.
Record instrument used (model and serial number).
Record readings (mSv/hr, cpm or cps)
Include appropriate diagrams or sketches.
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Requirement 25: 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• Occupational exposure assessment• Records of occupational exposure• Workers’ health surveillance
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assessment of occupational exposure
The measurement and assessment of occupational exposure can include one or more of:• whole-body or part-body doses arising from external
radiation (notably X-rays, gamma rays, beta particles or neutrons);
• the assessment of doses from intakes of specified classes of radionuclides;
• the assessment of doses following an accident or other incident
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Occupational exposure assessment
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Types of personal dosemeter:• Passive: TLD or film body badges • Active: Pocket ion chamber and electronic pocket dosimeters
None of the above dosimeters can detect very low energy beta emitters (e.g. tritium)
Passive dosimeters cannot be used for contamination surveys
Useful to have pre-set alarms and specified turn back values
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Occupational exposure assessment
Individual exposure assessment required for all those who work in controlled areas
May be used for those working in supervised areas (or use workplace monitoring & occupancy)
May require assessment of beta, gamma and neutron dose
Extremity dose or air sampling may be needed
Purpose of monitoring is to demonstrate that exposures are adequately controlled
Records of individual monitoring must be kept
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Records of occupational exposure
Employers, registrants and licensees have to maintain a formal dose record for each worker - to ensure that all assessed doses are properly recorded and summed, and compliance with limits is checked
Records must be maintained during and after the worker’s working life, at least until age of 75y, and for not less than 30 years after being subject to occupational exposure.
Records should• Demonstrate compliance with requirements• Identify significant changes in work environment• Give details of radiation surveys and occupancy where appropriate• Record reports on workplace where compliance with standards could be
adversely affected• Detail any appropriate action taken• Be accessible by individual worker and by the Regulatory Body
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Records of occupational exposure
The exposure records should include• Information on nature of work involving occupational exposure• Information on doses, exposures and intakes at or above
recording levels and data from which the doses have been evaluated
• In case of work under different employers, information on doses, exposure periods and dates of exposure under each employer
• Records of any doses due to emergency and or accidental situation should be distinguished from normal work doses with reference to any relevant investigations and maintained
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Health surveillance records should be confidential and preserved in a manner approved by the Regulatory Body.
The minimum period of record keeping should be the lifetime of the worker concerned, but longer preservation may be advisable.
Workers’ health surveillance
Primary purpose of health surveillance is to assess the initial and continuing fitness of employees for their intended tasks - based on general principles of occupational health
Employers, registrants and licensees have to provide the following with access to workers’ records of occupational exposure:
supervisor of the programme for workers’ health surveillance,the regulatory bodythe relevant employer
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Requirement 26: Information, instruction and training
Employers, registrants and licensees shall provide workers with adequate information, instruction and training for protection and safety.
They have to provide adequate information on health risks due to occupational exposure in normal operation, anticipated operational occurrences and accident conditions,
Also provide adequate instruction and training and periodic retraining in protection and safety, and adequate information on the significance of worker’s actions for protection and safety;
Additional provision for workers who could be involved in or affected by the response to an emergency
They have to maintain records of the training provided to individual workers.
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Requirement 27: Conditions of service
Employers, registrants and licensees shall not offer benefits as substitutes for measures for protection and safety.
Conditions of service of workers have to be independent of whether workers are or could be subject to occupational exposure
Extra salary or other benefits are not to be used as substitutes for proper protection and safety
Employers have to make all reasonable efforts to provide workers with suitable alternative employment when they are not allowed further occupational exposure
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Requirement 28: Special arrangements
Employers, registrants and licensees shall make special arrangements for female workers, as necessary, for protection of the embryo or fetus and of breast-fed infants. Employers, registrants and licensees shall make special arrangements for protection and safety for persons under 18 years of age who are undergoing training.
• Female worker are provided with information on the risk to the embryo or fetus due to exposure of a pregnant woman, and the importance for a female worker of notifying her employer if she suspects that she is pregnant or if she is breast-feeding;
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Special arrangements
• Employers have to adapt working conditions as may be necessary for the protection of embryo or foetus.
• Pregnancy is not a reason to exclude a female worker from work.
Employers, registrants and licensees have to ensure that no person under 16 years are not occupational exposed.
They also have to ensure that persons under 18 years are allowed access to a controlled area only under supervision and only for the purpose of training for employment or for studies in which sources are used.
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Assessment of Occupational Exposure Due to Intakes of Radionuclides, RS-G-1.2, IAEA (1999).
Assessment of Occupational Exposure Due to External Sources of Radiation, Safety Guide RS-G-1.3 IAEA (1999).
Optimization of Radiation Protection in the Control of Occupational Exposure, Safety Reports Series No 21, IAEA (2002)
Assessing the need for radiation protection measures in work involving minerals and raw materials, Safety Reports Series No. 49, IAEA (2006).
Further informationFurther information