Summary Report for Conduct of Kozloduy NPP Stress Tests

More documents

Recommendations

Info

“Kozloduy NPP” PLC SUMMARY REPORT for Conduct of Kozloduy NPP Stress Tests Table 5.1-5: Assessment of time period to fuel damage at initiating events with loss of power supply and ultimate heat sink. No. Initial condition of the unit Assessment result 1. Power operations Event is reduced to scenario of loss of normal and standby power supply, failure to all emergency DGs and additional DG. Time to core damage: 45 – 49 hours 2. Shut down reactor, planned cooldown at pressurized primary circuit and drained SG 3. Shut down reactor, planned cooldown at pressurized primary circuit and non-drained SG 4. Shut down reactor, planned cooldown at depressurized primary circuit 5. Shut down reactor, outage cooldown Event is reduced to scenario of loss of normal and standby power supply, failure to all emergency DGs and additional DG. Time to core damage: 66 hours 44 min Event is reduced to scenario of loss of normal and standby power supply, failure to all emergency DGs and additional DG. Time to core damage: 69 hours 44 min Event is reduced to scenario of loss of normal and standby power supply and failure to all emergency DGs and additional DG. Time to core damage: 7 hours 28 min Event is reduced to scenario of loss of normal and standby power supply and failure to all emergency DGs and additional DG. Time to core damage: - 3 days after shutdown: 9 hours 15 min - 18 days after shutdown: 16 hours 53 min 5.1.3.4.2 Off-site actions envisioned to prevent fuel damage Emergency response plan envisions usage of the mobile DG. 5.1.4 Measures to improve robustness to loss of ultimate heat sink Assessment is performed on condition, efficiency and availability of emergency water supply system from Shishamnov val; 5.2 SFP OF UNITS 5 AND 6 5.2.1 Loss of power supply 5.2.1.1 Loss of off-site power supply 5.2.1.1.1 Design schemes at loss of off-site power supply, sources, capacity and availability for operation of emergency power supply 153/202
“Kozloduy NPP” PLC SUMMARY REPORT for Conduct of Kozloduy NPP Stress Tests Spent Fuel Pools (SFP) are located in the containments and serve to store and maintain the spent fuel (to reduction of decay heat to the permissible level) during not less than three years. By 30.06.2011 in SFP 5 355 fuel assemblies and in SFP 6 365 fuel assemblies are stored. SFP cooling systems are the part of units 5 and 6 systems. Correspondingly normal and standby power supply SFP cooldown system of units 5 and 6 is similar to normal and standby power supply to the reactor installations. These systems are classified safety related normal operation systems. These are three-train systems (redundancy 3 х 100%) and are powered from the emergency DGs. 5.2.1.1.2 Independence of emergency power supply sources and measures to prolong operational time With two emergency DGs in operation (one per unit) total reserve of fuel and oil of the emergency DGs is sufficient for more than 38 days. 5.2.1.2 Loss of off-site power supply and loss of emergency DG The following Table provides the times for heating and evaporation of water to the level of the heated part of the assemblies in case of loss of off-site and emergency power. Two options for different fuel quantities have been considered. The first one for the current amount of spent fuel by 30.06.2011 and the second with full fuel removed from the core in the SFP after the reactor is taken out for a refuelling outage. The initial level in the SFP in each case is considered the one adequate for normal operation +28.80 m. If the additional DG is available, durations specified in the table prolong at least to 19 hours due to usage of water reserves in the boron control system tanks. Table 5.2-1: Time to occurrence of the main events in SFP in case of complete loss of alternate current power supply. Parameter SFP 5 SFP 6 Without unloading of the core Only spent fuel Time for heating to 50ºC to 100ºC [h:min] 22:52 39:53 Time from 50ºC to start of uncoverage of the fuel assembly [h:min] Spent fuel and unoaded core 136:21 (more than 5 days) 237:47 (more than 9 days) Time for heating to 70ºC to 100ºC [h:min] 1:52 1:48 Time from 70ºC to start of uncoverage of the fuel assembly [h:min] 17:28 16:51 154/202
Page 2 and 3:
“Kozloduy NPP” PLC SUMMARY REPO
Page 4 and 5:
Page 6 and 7:
Page 8 and 9:
Page 10 and 11:
Page 12 and 13:
Page 14 and 15:
Page 16 and 17:
Page 18 and 19:
“Kozloduy NPP” PLC Figure 1.2-2
Page 20 and 21:
Page 22 and 23:
Page 24 and 25:
Page 26 and 27:
Page 28 and 29:
Page 30 and 31:
Page 32 and 33:
Page 34 and 35:
Page 36 and 37:
Page 38 and 39:
Page 40 and 41:
Page 42 and 43:
Page 44 and 45:
Page 46 and 47:
Page 48 and 49:
Page 50 and 51:
Page 52 and 53:
Page 54 and 55:
Page 56 and 57:
Page 58 and 59:
Page 60 and 61:
Page 62 and 63:
Page 64 and 65:
Page 66 and 67:
Page 68 and 69:
Page 70 and 71:
Page 72 and 73:
Page 74 and 75:
Page 76 and 77:
Page 78 and 79:
Page 80 and 81:
Page 82 and 83:
Page 84 and 85:
Page 86 and 87:
Page 88 and 89:
Page 90 and 91:
Page 92 and 93:
Page 94 and 95:
Page 96 and 97:
Page 98 and 99:
Page 100 and 101:
Page 102 and 103: “Kozloduy NPP” PLC SUMMARY REPO
show all

Summary Report for Conduct of Kozloduy NPP Stress Tests

Create successful ePaper yourself

Delete template?

Save as template?