SAFRAN tool is developed under IAEA SADRWMS project to facilitate implementation of Safety Assessment methodologies, mainly for regulatory purposes in the field of pre-disposal waste management. The tool enables structured way to:
To perform a Safety Assessment one needs to use three different modules called “Facility”, “Regulatory framework” and “Safety Assessments”. Fourth module called “Waste producers” facilitates presentation of the waste streams and it is not necessary for assessing Safety Case.
“Facility” module provides description of the facility, rooms within the facility and areas within the rooms where waste management activities are performed. Every room can have more areas where only one waste management activity can take place. To describe rooms and areas, one should input Tables providing data for the source term for safety case scenarios, Safety elements and Physical elements. Physical elements by default contain Ventilation apart from which user-defined physical elements can be defined. It is important to notice that Safety elements can be linked to Safety assessment module scenarios by introducing Discussion objects pertaining to particular safety element in Facility module. That way Conclusion object from Safety assessment module can be linked to Discussion object providing direct answer to questions posed about particular safety element giving clear result for assessed safety case for both normal and accidental situations. For Areas it is necessary to define Waste management activities for which one needs to input effect of the activity on waste item within the waste stream. The effect of the activity on the waste being processed is presented by percentage of the waste pertaining to outputs from that particular waste management activity. Number of outputs from the waste management activity generally depends on the activity, but it has to be caped in mind that total quantity of waste before the activity and after should be the same. Waste inventory for the Areas are defined through Waste components for which one needs to provide waste volume, weight, radionuclide vector and type of packaging for waste. For sealed sources number of sources must be provided along with radionuclide vector. Once description of the Facility, Rooms, Areas, Waste components and outputs are finished one can use Block of activities Tab under Waste management activities Tab under Facility to produce picture representation of the waste stream for the waste management processes that actually takes place in the Facility. Under Waste management activity Tab one can introduce Check for clearance activity and make it available in a stream pertaining to certain waste management process. Check for clearance will automatically introduce two waste components, one pertaining to cleared waste and other to non-cleared waste.
After afore explained steps are performed, facility module is available to Safety assessment module where assessment will take place. In order to perform actual assessment of the safety case, Regulatory framework module must first be prepared to offer regulatory criterion for assessment of the safety cast. Afterwards Regulatory framework has to be linked to Safety assessment object, which represents safety case being assessed.
Regulatory framework module consists of two parts considering normal operation and accidental situation respectively. For both situations one need to add one or more Criterion’s represented by dose exposure levels. These Criterions than have to be linked to Safety assessment Endpoints. SAFRAN will compare Endpoint to linked Criterion and judge if safety case satisfies regulatory requirement or not. After Criterions in Regulatory framework module are defined, one needs to prepare a safety case scenario for which Safety assessment module is used.
In the Safety assessment module one can define purpose of the safety assessment by linking it to a certain physical element and one can introduce modifications if alternative configuration of the Site wants to be compared. To perform assessment of the safety case it is necessary to define Scope of the safety case by choosing parts of the facility or a whole facility to be considered, approach to be used in assessing safety case, endpoints for normal operation and accidental situation scenario and the scope for each scenario which is defined by dedicating parts of the facility which scenario is to consider. When this is done, one can run Analysis for normal and accidental situation and compare the results. Important is to note that in this part one can introduce a Discussion object that can be linked to Physical element for which a safety case is prepared. When the assessment is done, one needs to define a Conclusion object and linked it to a dedicated Discussion object in order to clearly demonstrate a basis for a conclusion made according to the safety assessment results and regulatory requirements. This effectively ends Safety assessment.