Lecture 2 - Protection against occ. exposure 1.ppt
1. IAEA
International Atomic Energy Agency
Protection Against Occupational
Exposure
Radiation Protection Programme
Day 9 – Lecture 1
2. IAEA
Objective
• To describe the situation involving
occupational exposure
• To identify the sources of routine and
reasonably foreseeable potential exposures and
to make a realistic estimate of the relevant
doses and probabilities
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3. IAEA
Content
• Safety Assessment
• Scope and structure of radiation protection
programme
• Assignment of responsibilities
• Role of the Radiation Protection Officer
• Quality assurance
• Emergency preparedness
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4. IAEA
Prior Radiological Evaluation
• Purpose is to describe the situation involving
occupational exposure
• This is the first step in development of a
Radiological Protection Program (RPP)
• The prior radiological evaluation should include:
• an identification of the sources of routine and
reasonably foreseeable potential exposures
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5. IAEA
Prior Radiological Evaluation
• a realistic estimate of the relevant doses and
probabilities
• Prior evaluation will help to determine what
can be achieved at the design stage to
establish satisfactory working conditions
through the use of engineered features
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6. IAEA
Safety Assessment
• Where authorization by registration or licensing is
required, the legal person applying for the
authorization is required to make a safety
assessment
• The safety assessment shall include, as
appropriate, a systematic critical review of:
• the nature and magnitude of potential
exposures and the likelihood of their
occurrence
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7. IAEA
Safety Assessment
• the limits and technical conditions for
operation of the source
• the ways in which structures, systems,
components and procedures related to
radiation protection or safety might fail,
singly or in combination, or otherwise lead to
potential exposures, and the consequences
of such failures
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8. IAEA
Safety Assessment
• the ways in which changes in the environment
could affect protection or safety
• the ways in which operating procedures related
to protection or safety might be erroneous, and
the consequences of such errors; and
• the protection and safety implications of any
proposed modifications
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9. IAEA
Safety Assessment
• The registrant or licensee shall take into
account in the safety assessment:
• factors which could precipitate a substantial
release of any radioactive substance and the
measures available to prevent or control such a
release, and the maximum activity of any
radioactive substance which, in the event of a
major failure of the containment, might be released
to the atmosphere
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10. IAEA
Safety Assessment
• The registrant or licensee shall take into
account in the safety assessment:
• factors which could precipitate a smaller but
continuing release of any radioactive
substance and the measures available to
prevent or control such a release
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11. IAEA
Safety Assessment
• The registrant or licensee shall take into
account in the safety assessment:
• factors which could give rise to the
unintended operation of any radiation beam
and the measures available to prevent,
identify and control such occurrences
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12. IAEA
Safety Assessment
• The registrant or licensee shall take into
account in the safety assessment:
• the extent to which redundant and diverse
safety features, being independent of each
other so that failure of one does not result in
failure of any other, are appropriate in order
to restrict the probability and magnitude of
potential exposures
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13. IAEA
Safety Assessment
• The safety assessment shall be documented
and, if appropriate, independently reviewed
within the relevant quality assurance program.
• Additional reviews shall be performed as
necessary for ensuring that the technical
specifications or conditions of use continue to
be met
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14. IAEA
Scope and Structure of the RPP
• The RPP covers the main elements
contributing to protection and safety
• The RPP is a key factor for the
development of a safety culture
• Development of a safety culture depends
on management commitment
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15. IAEA
• Whatever the situation, the basic structure of the RPP
should document, with an appropriate level of detail:
• the assignment of responsibilities for occupational
radiation protection and safety to different
management levels
• the designation of controlled or supervised areas
Scope and Structure of the RPP
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16. IAEA
• Whatever the situation, the basic structure of the
RPP should document, with an appropriate level of
detail:
• the local rules for workers to follow and the
supervision of work
• the arrangements for monitoring workers and
the workplace, including the acquisition and
maintenance of radiation protection
instruments
Scope and Structure of the RPP
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17. IAEA
• Whatever the situation, the basic structure of the RPP
should document, with an appropriate level of detail:
• the system for recording and reporting all the
relevant information related to the control of
exposures, the decisions regarding measures for
occupational radiation protection and safety, and the
monitoring of individuals
Scope and Structure of the RPP
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18. IAEA
Assignment of Responsibilities
• Licensees and registrants may appoint other people to
carry out actions and tasks related to their radiation
protection responsibilities, but they retain the
responsibility for the actions and tasks themselves
• Registrants and licensees shall specifically identify the
individuals responsible for ensuring compliance with the
Standards
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19. IAEA
Assignment of Responsibilities
• Radiation Protection Officers should be
appointed to oversee the application of
regulatory requirements
• Organizational structures should reflect the
assignment of responsibilities, and the
commitment of the organization to protection
and safety
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20. IAEA
Role of the Radiation Protection Officer
• The Radiation Protection Officer (RPO) (also
called health physics managers or health
physics officers) should take part in the planning
of activities involving significant exposures, and
should advise on the conditions under which
work can be undertaken in controlled areas.
• The RPO should review and approve Radiation
Work Permits (RWP’s)
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21. IAEA
• RPO’s should perform regular assessments (for example
on an annual basis) of the global exposure situation of
the facility, in order to:
• Evaluate the generic tendencies;
• Check any possible deviations;
• Monitor the effectiveness of the radiation
protection program, including the ALARA plan;
• Identify the main areas for improvement;
• Determine future goals for doses.
Role of the Radiation Protection Officer
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22. IAEA
Assignment of Responsibilities
• Depending on the size of the organization, management
should consider creating a specific committee with
representatives of the departments concerned with
occupational exposure
• This committee would review planning of jobs with
significant exposure potential to ensure proper controls
and that ALARA considerations have been factored into
the job plan
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23. IAEA
Role of the Qualified Expert
• Qualified experts shall be identified and made available
for providing advice on the observance of the Standards.
• In particular, qualified experts in radiation protection
should be identified and made available to provide
advice on a range of issues, including optimization of
protection and safety.
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24. IAEA
Role of the Qualified Expert
• Registrants and licensees shall inform the Regulatory
Authority of their arrangements to make available the
expertise necessary to provide advice on the
observance of the Standards. The information provided
shall include the scope of the functions of any qualified
experts identified.
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25. IAEA
Safety Culture
• A safety culture shall be fostered and maintained to encourage a
questioning and learning attitude to protection and safety and to
discourage complacency, which shall ensure that:
• policies and procedures be established that identify protection
and safety as being of the highest priority;
• problems affecting protection and safety be promptly identified
and corrected in a manner commensurate with their importance;
• the responsibilities of each individual, including those at senior
management levels, for protection and safety be clearly
identified and each individual be suitably trained and qualified;
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26. IAEA
Safety Culture
• A safety culture shall be fostered and maintained to encourage
a questioning and learning attitude to protection and safety and
to discourage complacency, which shall ensure that:
• clear lines of authority for decisions on protection and
safety be defined; and
• organizational arrangements and lines of communications
be effected that result in an appropriate flow of information
on protection and safety at and between the various levels
in the organization of the registrant or licensee.
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27. IAEA
Quality Assurance
• Quality assurance programs shall be established that
provide, as appropriate:
• adequate assurance that the specified requirements
relating to protection and safety are satisfied; and
• quality control mechanisms and procedures for
reviewing and assessing the overall effectiveness of
protection and safety measures.
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28. IAEA
Emergency Preparedness
• Emergency exposure situations may arise
as a consequence of an accident
• The basic obligations are to undertake
protective actions whenever they are
justified, and to optimize those actions so
as to produce the maximum net benefit.
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29. IAEA
Emergency Preparedness
• Each registrant or licensee responsible for sources for
which prompt intervention may be required shall ensure
that an emergency plan exists that defines on-site
responsibilities and takes account of off-site
responsibilities appropriate for the source and provides
for implementation of each form of protective action
• The decision whether or not emergency plans are
needed should result from the prior radiological
evaluation
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30. IAEA
Emergency Preparedness
• Emergency and contingency plans should
include a system for categorizing workers
involved in the immediate aftermath of the
accident — for example a list of persons
involved and their locations — and a
system to give a rapid initial assessment
of dose
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31. IAEA
Emergency Preparedness
• In the case of large sources, and nuclear power
facilities in particular, workers may need to be
involved in actions to protect the public
• Emergency plans prepared in advance should
include definition of the roles and responsibilities
of all workers concerned in the emergency
response.
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Editor's Notes
#2:The level of effort, formality and detail of the evaluation, and the scrutiny to which it is subjected, must be linked to the magnitude of the routine and potential exposures and the probabilities of these potential exposures.
#3:The level of effort, formality and detail of the evaluation, and the scrutiny to which it is subjected, must be linked to the magnitude of the routine and potential exposures and the probabilities of these potential exposures.
#4:The level of effort, formality and detail of the evaluation, and the scrutiny to which it is subjected, must be linked to the magnitude of the routine and potential exposures and the probabilities of these potential exposures.
#5:Examples would be the provision of shielding, containment, ventilation or interlocks. These considerations should aim to minimize the need for relying on administrative controls and personal protective equipment for protection and safety during normal operations. Subsequent consideration may then be given to additional operational procedures and restrictions that might be implemented to further control the workers’ exposure. Only if these measures are not sufficient to adequately restrict the dose to workers will prior evaluation go on to consider the use of special tools, personal protective equipment and specific task related training.
#13:Additional reviews shall be performed as necessary for ensuring that the technical specifications or conditions
of use continue to be met whenever:
(a) significant modifications to a source or its associated plant or its operating or maintenance procedures are envisaged;
(b) operating experience, or other information about accidents, failures, errors or other events that could lead to potential exposures indicates that the current assessment might be invalid; and
(c) any significant changes in activities, or any relevant changes in guidelines or standards, are envisaged or have been made.
#14:A safety culture is one which encourages a questioning and learning attitude to protection and safety and one which discourages complacency.
#15:Bullet (1) above includes corresponding organizational arrangements and, if applicable (for example, in the case of itinerant workers), the allocation of the respective responsibilities between employers and the registrant or licensee.
#18:The responsibility for the implementation of the RPP within an organization should thus be allocated by management to staff as appropriate. The responsibilities of each hierarchical level, from the top management to the workers, regarding each aspect of the RPP should be clearly delineated and documented in written policy statements to ensure that all are aware of them.
#19:The management structure should facilitate co-operation between the various individuals involved. The
RPP should be designed in such a way that the relevant information is provided to the individuals in charge of the various aspects of the work.
#22:The main role of this committee would be to advise senior management on the RPP. Its members should therefore include management staff from the relevant departments and workers with field experience. The functions of the committee should be to delineate the main objectives of the RPP in general, and operational radiation protection in particular, to validate the protection goals, to make proposals regarding the choice of protection measures and to give recommendations to management regarding the resources, methods and tools to be assigned to the fulfillment of the RPP.
In particular, qualified experts in radiation protection should be identified and made available to provide advice on a range of issues, including optimization of protection and safety.
#29:This prior radiological evaluation should indicate the essential features that need to be incorporated within the plan, the degree of planning being commensurate with the nature and magnitude of the risk and the feasibility of mitigating the consequences should an accident or emergency occur.
If only minor accidents have to be considered, the registrant or licensee should draw up a contingency plan, based on an assessment of the consequences of any reasonably foreseeable accident or incident, in order to restrict as far as is reasonably achievable any resulting exposure of workers on-site. Under many circumstances
such contingency plans may be very simple.
#30:Provision should also be made for appropriate decontamination facilities and for the reception and treatment in a local hospital of workers suspected of being contaminated or having contaminated wounds, or of having been exposed to doses near or in excess of the thresholds for deterministic effects. If a local hospital is not available, special emergency transport to hospital should be provided, by air if necessary.
#31:Regarding protection of the public, the avoidance of dose to the public (dose averted) should be balanced against the detriment associated with the intervention, including the dose to these workers.
Details of protective actions to be taken, protective clothing and monitoring instruments to be used, and dosimetry arrangements should also be specified. Consideration should be given to isolating the affected parts of the installation and ensuring that only authorized persons enter this area, in a controlled manner.
