AUTOMATIC SCRAM AND POST-EVENT OPERATOR ACTION

AUTOMATIC SCRAM AND POST-EVENT OPERATOR ACTION 

For research reactors, consideration is given to automatic actions to attain a safe state in the case of an external event when these actions are compatible with the speed of development of the external events. The facility should have protection capabihties in all operating modes and conditions. The systems in charge of this are considered safety related and consequently categorized for external events. In particular, operational limits and conditions of a seismic scram system including surveillance tests and intervals are based on the safety analysis for seismic events. Reference [5] provides information on automatic seismic trip systems for NPPs and other facihties. 

After the development of an extreme external event and after the operator has taken immediate action, a decision needs to be taken on restoring operation. Dedicated procedures are developed which set out the roles, responsibilities (which in some cases are subject to approval of the regulatory body) and a list of systems to be inspected prior to operation. 

Bearing in mind the hazard categorization described in Section 3, the following distinctions apply for emergency procedures  

A QA system compatible with the initiation of site evaluation activities should be established as soon as possible [7,48]. The programme should cover all the major tasks involved in site evaluation, design, monitoring and operation of the facility, but also the transfer of data between these tasks. 

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