Final answer:
Condensate or wastewater must not drain over heating units or door thresholds to prevent contamination, especially in power plants where water systems are strictly separated to avoid mixing radioactive and nonradioactive water.
Step-by-step explanation:
Condensate or wastewater shall not drain over heating units or door thresholds to prevent mixing with other systems, especially in settings like power plants where different water systems must remain separate. In such facilities, the three water systems: the condenser, the steam generator, and the reactor are designed to operate independently of each other. This segregation is critical because water in the reactor is radioactive and must be contained within the containment structure to avoid environmental contamination, whereas water in the steam generator and condenser is nonradioactive and used for cooling purposes.
Efficiency in these systems is key, as evidenced by the cooling tower operation where cooler air circulates over warmer water, enhancing the rate of evaporation. This evaporative cooling effect generates a plume of water vapor, visible above cooling towers, which is an efficient way to dissipate heat. It is this principle that allows large amounts of heat to be removed without significantly heating the surrounding air, thus ensuring efficient operation of the plant and the safety and integrity of water systems.