SAFETY CULTURE

It is not easy to define precisely what is meant by 'safety culture', although the International Nuclear Safety Advisory Group (INSAG) refers in this connection to the assembly of characteristics and attitudes in organizations and individuals which establish that, as an overriding priority, protection and safety issues receive the atten-tion warranted by their significance [13]. Nonetheless, the BSS are quite clear as to the results that a good safety culture will achieve:

"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:

(a) policies and procedures be established that identify protection and safety as being of the highest priority;

(b) problems affecting protection and safety be promptly identified and corrected in a manner commensurate with their importance;

(c) the responsibilities of each individual, including those at senior manage-ment levels, for protection and safety be clearly identified and each indi-vidual be suitably trained and qualified;

(d) clear lines of authority for decisions on protection and safety be defined; and (e) 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" [14].

The development of a good safety culture can only be achieved if the attitudes and behaviour of both the managers and the employees of an organization are condi-tioned in line with the requirements set out above.

In many serious accidents, deliberately or through inattention, managers allowed safety systems to degrade significantly and workers to improvise procedures or continue operations when engineered safety systems failed. Workers may have believed that management encouraged deviations from procedures in order to perform jobs more quickly — this belief being based, in part, on the evidence of management apparently turning a blind eye to any improvised methods. Management pressures may have been real, or management may not have noticed the improvisation. In other situations that did not result in accidents, managers deliberately bypassed radiation interlocks and substituted administrative controls to avoid a shutdown to repair a defective radiation monitor. In this way, violations of procedures, rather than the laid down procedures, became the normal methods of working. Not surprisingly, these violations of rules eventually led to accidents.

Failure of management to train staff in procedures and in the operation and purpose of safety equipment can cause workers to make serious errors. Even when training is provided, it should prepare workers to deal with rare but potential events and should not focus on production, with a few routine requirements for safety included.

For their part, it is necessary that workers have confidence that the act of uncov-ering a safety defect will be viewed positively and not negatively by their managers.

This means that an operator who suspends operations to correct the failure of a required safety system should expect praise, not criticism.

In a working environment in which the management and workers are co-operating to achieve safety, the result is greater than the sum of the parts. In this area, synergism is a reality, and what is recognized as a good safety culture is the result of that synergy. Conversely, failures in any one aspect have repercussions in other areas, so the breakdown of a safety culture can be rapid and dramatic.

3.1. Human factors The BSS require that:

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"Provision shall be made for reducing as far as practicable the contribution of human error to accidents and other events that could give rise to exposures, by ensuring that:

(a) all personnel on whom protection and safety depend be appropriately trained and qualified so that they understand their responsibilities and perform their duties with appropriate judgement and according to defined procedures;

(b) sound ergonomic principles be followed as appropriate in designing equipment and operating procedures, so as to facilitate the safe operation or use of equipment, to minimize the possibility that operating errors will lead to accidents, and to reduce the possibility of misinterpreting indica-tions of normal and abnormal condiindica-tions; and

(c) appropriate equipment, safety systems and procedural requirements be provided and other necessary provisions be made:

(i) to reduce, as far as practicable, the possibility that human error will lead to inadvertent or unintentional exposure of any person;

(ii) to provide means for detecting human errors and for correcting or compensating for them; and

(iii) to facilitate intervention in the event of failure of safety systems or of other protective measures" [15].

Human reliability has been defined as the probability of successful performance of only those human activities necessary for a reliable system. Human errors, some-times called 'human failure events', reduce human reliability. In the more formal analyses of human reliability and human errors, consideration of performance shap-ing factors is important. External performance shapshap-ing factors include the entire work environment, the equipment design, the kind of procedures that have been specified and the style of instructions given. All of these factors influence the probability of human error resulting from failure in attention, failure to remember crucial instruc-tions, lack of recognition of a potentially dangerous situation or the application of incomplete or inaccurate knowledge. In addition, it is possible to identify internal factors which are likely to give rise to the failures mentioned above, such as distrac-tion; mental or physical stress; high workload; changes in work routines, situations or plans; inadequacies in procedures, training or leadership; poor human-machine inter-face; or poor communications.

Human error is commonly considered to include unsafe actions and omission of required actions. It does not include malevolent behaviour intended to produce a harmful effect, although being alert to such behaviour is an important aspect of management supervision, especially in situations where such behaviour may give rise to a significant hazard. An exceptional type of unsafe action involves mistaken intentions

or deliberate rule breaking. In these situations, people do not commit a human error in the everyday sense of the term; rather, they circumvent a safety rule or make a choice in order to reach the goal they believe is correct at the time. Such an action is distinctly different in its cause from other kinds of unsafe action.

Through a risk assessment of a given device, the different kinds of human error or equipment failure that can result in unsafe outcomes can be identified before these errors or failures occur in practice. Techniques for such assessments have been described by the International Commission on Radiological Protection [16]. The management and operators of the installation may then plan the steps they would take if such an error or failure occurred or can decide whether some simple change in design or operating practice could remove the potential hazard before an individual was harmed. In addition, by using risk assessment techniques, management may be able to explore whether changes in operation (such as staffing changes) will have an effect on safety.

Investigation of event sequences shows that certain significant patterns of behaviour seem to play a role in potential exposure that is not always recognized in traditional risk assessments. Perhaps the most important of these behaviour patterns are circumventions, as described above. For example, it may become common for staff to ignore radiation alarms if the alarms are prone to false signals. This phenomenon of ignoring warning signals is important in its contribution to the erosion of safety.

In order to avoid such human errors, management needs to ensure that individuals have the knowledge and skills necessary to perform their assigned tasks and respon-sibilities. In addition to knowledge, skills, procedures and rules, training needs to emphasize that engineered systems can fail. Workers must understand that every warning or alarm is to be believed until an expert determines whether the alarm is real or false. Practice exercises and drills that stress these lessons may be particularly effective. Instructions about safety control systems and warning signs need to be available in the workers' native language. The supervisor needs to identify perfor-mance failures and to take appropriate action to reduce the likelihood of repetitions.

Traditionally, 'human error' has focused on direct control of, or influence on, equip-ment immediately before the accident. This narrow view, restricted to 'operator error', provides only a partial approach to accident prevention. A successful approach to reducing human error should look at all stages of operation and should take into account management and organizational issues.

3.2. Supervision

A key individual in the management-worker chain of interaction is the supervisor.

Whenever supervisors failed to make rules understood or to take action when rules were violated, accidents eventually happened. Effective management provides comprehensive safety training to supervisors and holds the supervisor accountable for

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worker observance of the local rules and procedures. The supervisor is responsible for making the local rules and procedures and the protective measures and safety provisions known to those workers to whom they apply and to other persons who may be affected by them. The supervisor needs to monitor worker compliance with rules and to take corrective actions (training, improving procedures, clarifying rules or taking disciplinary action, as appropriate) when deviations occur.

To provide adequate supervision of radiation safety and training, licensees or registrants will normally need to designate a qualified expert to serve as Radiation Protection Officer. The Radiation Protection Officer often has the primary responsi-bility for providing training to workers on the health risks arising from their occu-pational exposure and on the significance of their actions for radiation protection and safety.