The decay heat drops off very slowly after about 1 day where the decay power is already below 2% of the operating power of the reactor.

在核反应产生的热量降至平时的2%后的第一天，衰变热就降低得很缓慢乐。

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PLC power control system, having been developed, simulated the transient process of the core decay power from 8% full power to 2% full power while blackout accident.

开发PLC功率调节系统，模拟了全厂断电事故工况下堆芯衰变功率从堆芯8%额定功率到堆芯2%额定功率的变化过程；

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RTGs power many space missions — including NASA's Cassini and New Horizons probes — as the slow decay of small pellets of radioactive material produces heat that can be turned into electricity.

RTG已为许多太空任务提供动力，包括美国宇航局的“卡西尼号”和“新视野”探测器。在放射性物质的小球衰退过程中可以产生出热量，从而将其转化为电能。

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If the cooling system were to lose power during the initial decay period of 24 to 48 hours, a meltdown would likely follow.

FORBES: U.S. Military Scrambles to Avoid Nuclear Meltdown in Japan

The tsunami destroyed the diesel generators that provide power to drive the pumps that circulate the water coolant through the reactor that removes decay heat.

FORBES: Explainer: What Caused The Incident At Fukushima-Daiichi

If the offcuts weren't fed into power stations, they would be burned as waste or left on the ground to decay, producing methane and CO2.

BBC: Biomass may hinder climate fight