Proposal for a new HO-1 signal ensuring protection against uncontrolled withdrawal of control assemblies. Rev. 0

The previous proposal for a new HO-1 signal which was based on the coolant temperature at the reactor core outlet has not been accepted because this principle is not considered to be reliable enough. The Dukovany management required a HO-1 signal derived directly from the quantities measured. Now it proposed that a new HO-1 signal can be derived from the primary circuit pressure with a setting of 13.3 MPa. Testing analyses which were performed demonstrate that this signal would intervene rapidly enough in the majority of conceivable events. (P.A.)