Symptom based emergency response guidelines

Following a beyond design basis accident (BDBA) in an advanced gas cooled reactor (AGR), leading to an interruption in post-trip heat removal, several hours are available to re-establish satisfactory operation of the reactor´s emergency cooling systems. To aid the operator, following a BDBA, symptom based emergency response guidelines (SBERGs) have been developed. The guidance contained within the SBERGs is relevant to situations where the fuel is largely contained within the fuel pins and the geometry of the fuel pins and other circuit components is essentially undisturbed. Operator/emergency control guidance for degraded core conditions is contained within the severe accident guidelines (SAGs). Guidance to the operator is thus given in event based procedures contained in station operating manuals (mandatory), SBERGs and SAGs (both advisory)