*4.3. Maintenance*

In Figure 8, the sudden changes in the daily power average represented an abnormal event of the power station and they are marked by event numbers in chronological order. Event at hour 55 (➊), the power station suffered a shutdown due to initial wiring mistake. Normal operation resumed after correction. Events at hour 497 (➋), hour 1602 (➌), and hour 2280 (➎) were shutdowns caused by exhaustion of fuel. The power station resumed operation after replenishment. At hour 2006 (➍), the fuel concentration was changed for the summer. Event at hour 3165 (➏) was the first failure when the rusted buckle of dosing pump 2 broke and the deteriorated dosing pump 4 was also replaced. The power station resumed power generation after maintenance. After hour 3581 (➐) the characteristics of 4th stack became abnormal, and the rest of the stacks became flooded and failed subsequently. The power station stopped its operation and concluded the long-term test after hour 3628.
