Design-Basis Analysis Conservatisms

The results of the analysis should be assessed to gain confidence that they provide an adequate representation of the risk from the plant. If there are areas where it is judged that the risk estimates are excessively conservative or optimistic, the analysis should be revised to make it more realistic. Excessive conservatism can occur if the safety system success criteria are based on conservative design basis transient analysis and conservative critical safety function success criteria rather than on the best estimates recommended for the PSA. Excessive optimism can occur if potential initiating events are inappropriately screened out. 

Describe three key conservatisms inherent in traditional design basis loss of coolant accident analysis with respect to long-term core coolability. 

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