1. After a reactor is shutdown, a considerable amount of sensible (or stored) heat is still present in the fuel rods and heat continues to be generated by the decay of fission products and by fission caused by delayed neutrons.
1. 停堆以后,燃料組件內仍然存在大量的熱量,同時裂變產物的衰變和緩發中子引發的剩余裂變還會產生新的熱量。
2. The sensible heat and delayed fission heat are removed within about half a minute and then only the decay heat determines the cooling requirements.
2. 存儲的能量以及緩發中子的能量在半分鐘內就導出了,只有剩余的衰變熱的導出取決于冷卻系統的能力。
3. The thermal power from this source is initially about 7% of the operating power at shutdown, then decreased to somewhat more than 6% after 1 second, to 1.3% after 1 hour and 0.4% after day.
3. 停堆瞬間的熱功率約為7%額定功率,1秒后降至6%,1小時后至1.3%,1天后0.4%。
4. The residual heat removal system also called shutdown cooling system is provided to remove the decay heat from the core to the cold shutdown temperature at controlled rate and maintains this temperature until the plant is started up again.
4. 余熱排出系統又稱為停堆冷卻系統,其主要功能就是以可控速率導出剩余衰變熱,直至冷停堆的溫度值,并保持此溫度直到電廠再次啟動。
5. In some nuclear power plants, the residual heat removal system also serves as part of the emergency core cooling system, during the injection and recirculation phase following a Loss of Coolant Accident (LOCA)5. 在某些電廠,在LOCA后的注射和再循環階段,停冷系統也作為應急堆芯冷卻系統的一部分。
6. The residual heat removal system consists of two residual heat exchangers, two residual removal pumps and the associated piping, valves and instrumentation for operational control.
6. 停冷系統有2個停冷熱交換器,2臺停冷泵以及相關的管道,閥門和儀表組成。
7. The inlet line to the residual heat removal system is connected to the hot leg of one of the reactor coolant loop, while the return lines are connected the cold legs of each of the reactor coolant loops.
7. 停冷系統的吸入口取自一個主管道的熱段,回水注入管則與每個主管道的冷段相連。
8. The delay heat is transferred to the component cooling water circulating through the shell side of the residual heat exchangers.
8. 熱量的移出是靠停冷熱交換器殼側的設冷水來實現的。
9. The initial phase of reactor cooldown is accomplished by transferring heat from the reactor coolant system to the steam and power conversion system through the steam generator.
9. 停堆初期(第一階段)的冷卻過程:通過蒸汽發生器將反應堆冷卻劑系統的能量傳輸給二次側的蒸汽。
10. The second phase of cooldown starts with the residual heat removal system being placed in operation approximately four hours after reactor shutdown when the temperature and pressure of the reactor coolant system are approximately 180℃ and 2.94MPa, respectively.
10. 停堆大約4小時以后,當主系統溫度和壓力分別降至180度個2.94MPa,停冷系統投入運行,用于第二階段的冷卻。
11. Both residual heat removal pumps are utilized during refueling to pump borated water from the refueling water storage tank to the refueling cavity.
11. 換料時,2臺停冷泵啟動運行,用于將換料水箱的水輸送至換料水池。
12. To assure reliability, the two residual heat removal pumps are connected to separate electric buses and each bus is automatically transferred to a separate emergency diesel supply.
12. 為保證可靠性,兩臺停冷泵分別由兩條獨立的母線供電,兩條母線可以分別自動切換到獨立的應急柴油機供電。