1. Group 1
Best Group

2. Kim Sea Jun Kim Byoung Koo Kim Ki Jun Bu Hyung Sik Lee Dong Woo
Yang Won Chel

3. Malfunction List
B-12. Leakages of Reactor Coolant Into Containment or Into The Secondary System
D-28,  Reactor Coolant Pump Shaft Break
D-26,  Reactor Coolant Pump Trip

4. Case #1 B-12 Leakages of reactor coolant into containment
Leakages of reactor coolant into the secondary system
Break node : 1
Leak size : 3000cm2

5. Steam generator

6. Working condition S/G Operating temp 330ºc Operating pressure 150 atm
Material
Inconel

7. Rupture initial condition
Parameter
Assumed Value
Core Power Level, MWt
2871
Core Inlet Coolant Temp ºC
298.89
Reactor Coolant System Pre(kg/cm2A)
163.45
Core Mass Flow Rate (kg/hr)
61.6
One Pin Integrated Radial Peaking Factor
1.515
Steam Generator Pressure (kg/cm2)
1144
Moderator Coefficient Multiplier
0.0
Doppler Coefficient Multiplier
1.0
CEA Worth at Trip, %
-9.0
Steam Generator Water Level % 95

8. Diagnosis of the SGTR Radiation monitor alarm
RCS pressure level  decrease
Pressurizer level  decrease
Affected steam generator level  increase

11. Sequence of events for the steam generator tube rupture
0.0
Tube Rupture Occurs
0.45
High Steam Generator Level
0.55
Trip Breaker Open
Turbine Trip; Stop Valves Closed
MSIS Generated on High Steam Generator Level,
5.0
Main Steam Safety Valves Open, Psia (kg/cm2A)
5.5
Main Steam and Main Feedwater Isolation Valves Close Completely
10.0
Maximum Steam Generator Pressure
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
920.0
Safety Injection Flow Initiated
Pressurizer begins to refill
1800
Operator isolates the Dammaged Steam Generator and Initiates Plant Cooldown at 55.6ºC/hr for the 1.5-hour time period
28800
Shutdown Cooling Entry Conditions are Assumed to be reached, RCS

12. Radiological Consequences of The SGTR
Location
Offsite Doses
GIS
PIS
Exclusion Area Boundary 0-2 hr
Thyroid
1.58
4.71
Whole Body
1.85
2.25
Low Population Zone outer Boundary 0-8 hr
0.1
2.62
1.06
1.26

13. Every Thing is all right.
Conclusion
Radiological releases at SGTR event are well in the 10 CFR 100 Guidelines .
RCS and main steam system keep the integrity firmly.
No violation of the fuel thermal limit occurs.
Every Thing is all right.

14. Loss of External Power
Same as w/o Loss of External Power before Reactor Trip
Reactor Trip  Turbine-Generator Trip
Unstable Electricity Grid (Frequency Decrease)
Trying to Correct Frequency
Separate from Grid  Loss of External Power

15. Sequence of events for the steam generator tube rupture with Loss of External Power
0.0
Tube Rupture Occurs
0.45
High Steam Generator Level
0.55
Trip Breaker Open
Turbine Trip; Stop Valves Closed
MSIS Generated on High Steam Generator Level,
3.55
Loss of External Power
4.4
Main Steam Safety Valves Open, Psia (kg/cm2A)
5.5
Main Steam and Main Feedwater Isolation Valves Close Completely
12.95
Maximum Steam Generator Pressure
946.95
Safety Injection Flow Initiated
1422.0
Pressurizer is exhausted
1800
Operator isolates the Dammaged Steam Generator and Initiates Plant Cooldown at 55.6ºC/hr for the 1.5-hour time period
28800
Shutdown Cooling Entry Conditions are Assumed to be reached, RCS

16. Difference in comparison with Case w/o Loss of External Power
After Reactor Trip, RCS Pressure decrease suddenly
RCP decelerate
Coolant level decrease  Boiling occurs in Reactor Head area
RCS pressure decreasing velocity decelerate because of Air Bubble
Air bubble disappeared after Safety Injection

17. Radiological Consequences of The SGTR with Loss of External Power
Location
Offsite Doses
GIS
PIS
Exclusion Area Boundary 0-2 hr
Thyroid
1.72
5.03
Whole Body
1.63
1.84
Low Population Zone outer Boundary 0-8 hr
1.14
0.28
9.44
1.03

18. Conclusion
Radiological releases at SGTR with Loss of External Power event are well in the 10 CFR 100 Guidelines .
RCS and main steam system keep the integrity firmly.
RCP stop dose not cause Accident.
No violation of the fuel thermal limit occurs.