Science and Technology of Nuclear Installations

Research Article

Analysis and Estimation of Core Damage Frequency of Flow Blockage and Loss of Coolant Accident: A Case Study of a 10 MW Water-Water Research Reactor-PSA Level 1

Table 3

System fault tree with the top event “no pool isolation”.
Basic eventComponents failure identificationProbability
1Operator fails to close manual butterfly valves1.000 × 10−2
2Manual butterfly valves fail in an open position3.600 × 10−6
3Operator fails to give a signal to pneumatic valves1.000 × 10−2
4No electric power2.790 × 10−6
5Pneumatic valves fail stuck in the open position8.200 × 10−5
6Human error1.000 × 10−2
7Sensor T2 fails2.350 × 10−2
8Relay T2 fails to open6.970 × 10−4
9Sensor fails to give a signal2.350 × 10−2
10Relay T1 fails to open6.970 × 10−4