Plant specific verification and validation
In Module 3, verification and validation were addressed at a high level. As both the SAMG and the emergency organisation are highly plant specific, actual verification and validation should be carried out on a plant-specific basis and in conformance with the plant-specific ERO.
Verification
In Module 3, the basic characteristics of the verification process were mentioned. Now that the organisation and implementation aspects have been included, the elements of the verification process which are dependent on the type of organisation can be added, so that a full plant-specific verification can be performed.
Validation
There are a number of possible approaches for validation of SAMGs. To date, successful validation of SAMG has been performed using table top methods for TSC staff and full scope simulators to exercise the operator controlled transitions from EOPs. For plants with full scope simulators capable of simulating severe accident conditions, the entire exercise may be performed using the simulator.
In either case, some severe accident analysis (or simulator cases) will be required prior to the validation to serve as a basis for the plant response and to identify decision points. The amount and scope of such analysis must be defined once the detailed approach to the validation is finalized.
Both individual exercises (i.e. exercising the TSC, the main control room or any other interfacing part of the plant emergency response team separately) and integrated exercises (i.e. where the whole team is involved) should be performed.
In setting up the validation programme for plant specific severe accident management guidance, a number of factors must be considered including:
  (a) The general approach - table top exercises, use of simulators or plant analysers, integrated versus individual exercises.
  (b) The supporting analysis needs, method to provide them, codes to be used, possible use of scenario templates, etc.
  (c) The staffing of the validation team, in particular the exercise controllers and technical advisers. These are    personnel who are not part of the team exercising, but who are responsible for running and coordinating the drill    or exercise. Their capabilities must include the ability to define credible plant conditions for the exercise on the spot.
  (d) The validation should be carried out in as realistic environment as possible, also taking into account the acceptable    time frame for accident management.
  (e) The validation exercise should aid in ensuring that SAMGs strategies can be used as planned, taking into consideration    such items as corrections or enhancements to strategies, feasibility of local actions, equipment/resource availability,    timing considerations especially for strategies that entail the use of portable equipment, etc.
  (f) The validation should include provisions to evaluate the ability to meet time critical operator actions to support design    analysis and time sensitive actions to support regulatory requirements and station commitments.
Trained staff should be able to execute the SAMG on the basis of the available systems, resources, local actions, organisation of the ERO/TSC, availability of staff and possibility to shift staff, etc. If possible, SAMG should be validated on a full scope simulator. Alternatives are engineering simulators, plant analysers, table top exercises, as mentioned above.
See TECDOC 1352 Read more
As already noted in Module 3, it is important that complex scenarios are used whose mitigation would require many guidelines to be initiated. The validation should activate all parts of the ERO which have responsibility for SAMG.
Once the SAMG has been validated, it is useful to have a full scope ERO exercise, to test the integration of the SAMG in the overall Emergency Response Organisation.
|