Types of monitoring programme

A monitoring programme is one component of the radiation protection programme, and para. 3.101 of GSG-7 [11] divides it into four primary types:

— Routine monitoring;

— Special monitoring;

— Confirmatory monitoring;

— Task related monitoring for a specific operation.

In addition to exposure pathways relevant to those locations, GSG-7 [11] states:

“3.102. Each of these types of monitoring programme can be subdivided on the basis of the location of the monitoring....

“3.103. Individual monitoring can be further subdivided into monitoring for external exposure, for internal exposure and for skin contamination.

Workplace monitoring can be further subdivided into monitoring for external radiation, for air contamination and for surface contamination. The details of the programmes will be influenced by factors such as the type and energy of the radiation and the radionuclides involved....

“3.104. The programme design should reflect the objectives of the monitoring programme, and these should be clearly specified and recorded.

...A distinction should be made in the programme between monitoring for the purpose of controlling operations and monitoring for the formal assessment of exposure to meet regulatory requirements.

“3.105. The equipment to be used in the monitoring programme should be suitable for the types of radiation and the forms of radioactive material encountered in the workplace. The equipment should be calibrated to meet appropriate standards. ...

“3.106. The design and implementation of a monitoring programme should conform to the quality assurance requirements embodied in the management system to ensure that procedures are established and followed correctly and to ensure that records are promptly compiled and correctly maintained. The design of the monitoring programme should indicate the records that should be kept, and the associated procedures for keeping and discarding records. All of these aspects should be reviewed regularly, at predetermined intervals or following any major change in operations of the installation or in regulatory requirements. The purpose of such reviews should be to ensure that the monitoring effort (type, frequency and extent) is appropriately employed. The information should also be used to identify both good and bad features of operating procedures, and both good and bad design characteristics.”

5.3.1. Demonstration of compliance with regulatory and corporate requirements

There will be regulatory requirements for worker doses, discharges and other matters for protection and safety. Requirement 14 of GSR Part 3 [10] states:

“Registrants and licensees and employers shall conduct monitoring to verify compliance with the requirements for protection and safety.

“3.37. The regulatory body shall establish requirements that monitoring and measurements be performed to verify compliance with the requirements for protection and safety. The regulatory body shall be responsible for review and approval of the monitoring and measurement programmes of registrants and licensees.”

The operator is likely to have corporate requirements with respect to the protection of human health and the environment from its operations.

Paragraph 3.38 of GSR Part 3 [7] states the key criteria for monitoring that need to be considered:

“Registrants and licensees and employers shall ensure that:

(a) Monitoring and measurements of parameters are performed as necessary for verification of compliance with the requirements of these Standards;

(b) Suitable equipment is provided and procedures for verification are implemented;

(c) Equipment is properly maintained, tested and calibrated at appropriate intervals with reference to standards traceable to national or international standards;

(d) Records are maintained of the results of monitoring and verification of compliance, as required by the regulatory body, including records of the tests and calibrations carried out in accordance with these standards;

(e) The results of monitoring and verification of compliance are shared with the regulatory body as required.”

Furthermore, techniques need to be sufficiently sensitivity to demonstrate that outcomes are within regulatory and corporate limits and that monitoring results are correct and accurate. Verification includes auditability and chain of custody of samples and dosimeters. Dosimeters, procedures, analytical methods and computer algorithms used also need to meet international standards and techniques.

5.3.2. Operational control

Requirement 24 of GSR Part 3 [10] states:

“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.

...

“Monitoring of the workplace

“3.96. Registrants and licensees, in cooperation with employers where appropriate, shall establish, maintain and keep under review a programme for workplace monitoring under the supervision of a radiation protection officer or qualified expert.

“3.97. The type and frequency of workplace monitoring:

(a) Shall be sufficient to enable:

(i) Evaluation of the radiological conditions in all workplaces;

(ii) Assessment of exposures in controlled areas and supervised areas;

(iii) Review of the classification of controlled areas and supervised areas.

(b) Shall be based on dose rate, activity concentration in air and surface contamination, and their expected fluctuations, and on the likelihood and magnitude of exposures in anticipated operational occurrences and accident conditions.

“3.98. Registrants and licensees, in cooperation with employers where appropriate, shall maintain records of the findings of the workplace monitoring programme. The findings of the workplace monitoring programme shall be made available to workers, through their representatives where appropriate.”

The key criteria for operational control are:

(a) Responsiveness and availability: Results need to be available to operators in a timely fashion. For process control this is likely to include real time monitoring.

(b) Clarity and simplicity for managers and workers: To facilitate control by operators, operational monitoring results need to be available in a form that provides clear information about the status of processes and the working environment.

5.3.3. Purpose of contamination monitoring

The main purposes of contamination monitoring are as follows:

(a) To verify the efficiency of engineered controls in the plant and process;

(b) To confirm good housekeeping practice;

(c) To confirm area designations;

(d) To identify contaminated areas and the level of contamination;

(e) To identify the spread and buildup of contamination;

(f) To monitor items and people exiting designated areas.

5.3.4. Assessment of occupational exposures Requirements 20 and 25 of GSR Part 3 [10] state:

“The regulatory body shall establish and enforce requirements for the monitoring and recording of occupational exposures in planned exposure situations.

...

“Employers, registrants and licensees shall be responsible for making arrangements for assessment and recording of occupational exposures and for workers’ health surveillance.”

5.3.4.1. Criteria for determining techniques

The key criteria for monitoring that need to be considered are similar to those for other compliance monitoring (see Section 5.3.1). In addition, dosimetry service providers are expected to be approved by the regulator, and exposure records are to be maintained.

5.3.4.2. Similar exposure groups

Similar exposure groups (SEGs) are groups of workers who have the same general exposure to sources of radiation. They are identified to determine occupational exposures based on workplace environmental monitoring and occupancy, to assess doses and to analyse exposures, trends and operational performance. In defining SEGs, the following are considered:

— The similarity and frequency of the tasks they perform;

— The materials, processes and proximity to radiation sources in their work;

— The similarity in how they perform the tasks.

Because of the relative ease and low cost of assessing external exposure using personal dosimeters (e.g. optical stimulated luminescence dosimeters

(OSLDs), TLDs), the use of SEGs for external exposure groups is less common. However, they can be used for groups less frequently exposed to significant occupational exposure. It would be appropriate to define SEGs where individuals are not likely to exceed a set dose, to demonstrate that no individual monitoring is necessary. These groups can be usefully aligned with industry standard descriptions of uranium worker roles in the comparative assessment of doses and trends.

5.3.4.3. Verification of design basis

The main objective is to assess changes over time, starting with a high level of monitoring to gain confidence in the results and scaling back the programme when the design basis has been verified.

5.3.4.4. Assessment against trigger levels for investigation or intervention

Requirement 16 of GSR Part 3 [7] states:

“Registrants and licensees shall conduct formal investigations of abnormal conditions arising in the operation of facilities or the conduct of activities and shall disseminate information that is significant for protection and safety.

“3.45. Registrants and licensees shall ensure that information on both normal operation and abnormal conditions that are significant for protection and safety is disseminated or made available, as appropriate, to the regulatory body and relevant parties, as specified by the regulatory body.

This information would include, for example, details of doses associated with given activities, data on maintenance, descriptions of events and information on corrective actions, and information on operating experience from other relevant facilities and activities.

“3.46. Registrants and licensees shall conduct an investigation as specified by the regulatory body in the event that:

(a) A quantity or operating parameter relating to protection and safety exceeds an investigation level or is outside the stipulated range of operating conditions; or

(b) Any equipment failure, accident, error, mishap or other unusual event or condition occurs that has the potential for causing a quantity to exceed any relevant limit or operating restriction.

“3.47. The registrant or licensee shall conduct an investigation as soon as possible after an event and shall prepare a written record of its causes, or suspected causes, including a verification or determination of any doses received or committed and recommendations for preventing the recurrence of the event and the occurrence of similar events.

“3.48. The registrant or licensee shall communicate to the regulatory body and to any other relevant parties, as appropriate, a written report of any formal investigation relating to events as prescribed by the regulatory body, including exposures giving rise to doses exceeding a dose limit. The registrant or licensee shall also immediately report to the regulatory body any event in which a dose limit is exceeded.”

5.4. GENERAL DOSE CONSIDERATIONS