Nuclear Engineering Problem Probability of core damage pleas

Nuclear Engineering Problem: Probability of core damage please help

In 1983, Salem Nuclear Power Plant in New Jersey experienced an anticipated transient without scram (ATWS) - a transient occurred where a reactor trip signal was generated, but the reactor failed to automatically shutdown on demand. In such an event, neither the ECCS nor the secondary side are capable of continued heat removal if the reactor is at full power - with the turbine tripped on the reactor trip signal, there are not adequate steam flow paths on the secondary side to remove all of the heat generated by fission. In such an event, any one of the following actions will successfully terminate the event without core damage: Manually trip the reactor - probability of success = 0.999 Place control rods in manual and manually insert to shutdown - probability of success = 0.8 Manually start emergency boration to shutdown - probability of success = 0.9 Locally open reactor trip breakers in sufficient time to trip the reactor - probability of success = 0.8 Locally de-energize the motor generator sets providing power to the rod control system in sufficient time - probability of success = 0.7 What is the core damage probability if an ATWS were to occur with the above probabilities of successful mitigation of the ATWS?

Solution

Place control rods in manual and manually insert to shut down.

Reason:

Reactor trip function is to insert control rods into the core reactor and shut down the plant in very short time. ( about 3 second)

Control rods are composed of chemical elements to absorb the neutrons during fission reaction. Absortion of neutron will lead to decrease in reaction eventually stop the reaction at one point of time.

The control rods can manually be inserted so my shifted to manual mode the Reactor trip is manual mode or control rod in manual mode the core damage is avoided.