| Major Events | Basic Events | Coding |
| Stress Cracks | J1 | |
| Thermal Overheating | J11 | |
| Temperature Fluctuation | J12 | |
| Sensor Failure | J111 | |
| Relief Valve Failure | J121 | |
| Stress Rupture (J) | Creep Failure | J2 |
| Overheating | J21 | |
| Long-Term Overheating | J211 | |
| Short-Term Overheating | J212 | |
| Pressure Relief Valve Failure | J2111 | |
| Temperature Sensor Failure | J2121 | |
| Vibration | K1 | |
| Defects | K11 | |
| Thermal Stress | K2 | |
| Fatigue (K) | Temperature Sensor Failure | J2121 |
| Corrosion Effect | K3 | |
| Material/Structural Defect | K31 | |
| Fireside Corrosion | X1 | |
| Fuel Ash | X11 | |
| Personnel Faults | X111 | |
| Embrittlement | X12 | |
| Sulfidation | X13 | |
| General Impurities | X131 | |
| Corrosion (X) | Nucleate Boiling | X14 |
| Material Impurities | X141 | |
| Carbide Graphitization | X15 | |
| Waterside Corrosion | X2 | |
| Dew Point | X21 | |
| Oxidation | X22 | |
| Formation of Sigma Phase | X23 | |
| Pitting | X24 | |
| Intergranular | X25 | |
| Fly Ash | Y1 | |
| Erosion (Y) | Falling Slag | Y2 |
| Soot Blowers | Y3 | |
| Fuel Ash | Y4 | |
| Oxidation | X22 | |
| Lack of Quality Control (Z) | Chemical Excursion | Z1 |
| Weld Defects | Z2 | |
| Material/Structural Defects | K31 |