Types of Nuclear Reactors

Boiling Water Reactor

沸腾水反应堆

In the boiling water reactor the same water loop serves as moderator, coolant for the core, and steam source for the turbine.

在沸水反应堆中，同一水循环系统同时担任慢化剂、反应堆冷却剂和汽轮机蒸汽源的作用。

In the boiling water reactor (BWR), the water which passes over the reactor core to act as moderator and coolant is also the steam source for the turbine. The disadvantage of this is that any fuel leak might make the water radioactive and that radioactivity would reach the turbine and the rest of the loop.

在沸水堆（BWR）中，流经反应堆核心用作慢化剂和冷却剂的水同时也是汽轮机的蒸汽源。其缺点是任何燃料泄漏都可能导致水变得放射性，并使放射性物质到达汽轮机和循环系统其余部分。

A typical operating pressure for such reactors is about 70 atmospheres at which pressure the water boils at about 285¡C. This operating temperature gives a Carnot efficiency of only 42% with a practical operating efficiency of around 32%, somewhat less than the PWR.

这类反应堆的典型工作压力约为70个大气压，在此压力下水的沸点约为285°C。这种工作温度对应的卡诺效率仅为42%，实际工作效率约为32%，略低于压水堆的效率。

Pressurized Water Reactor

压水堆

In the pressurized water reactor, the water which flows through the reactor core is isolated from the turbine.

在压水堆中，流经反应堆核心的水与涡轮机隔开。

In the pressurized water reactor (PWR), the water which passes over the reactor core to act as moderator and coolant does not flow to the turbine, but is contained in a pressurized primary loop. The primary loop water produces steam in the secondary loop which drives the turbine. The obvious advantage to this is that a fuel leak in the core would not pass any radioactive contaminants to the turbine and condenser.

在压水堆（PWR）中，流过反应堆核心用作慢化剂和冷却剂的水不流入涡轮机，而是被限制在加压的主循环中。主循环中的水在次循环中产生蒸汽，驱动涡轮机。这种设计的明显优势在于，如果燃料芯块发生泄漏，放射性物质不会进入涡轮机和电容器。

Another advantage is that the PWR can operate at higher pressure and temperature, about 160 atmospheres and about 315 C. This provides a higher Carnot efficiency than the BWR, but the reactor is more complicated and more costly to construct. Most of the U.S. reactors are pressurized water reactors.

另一个优势是，PWR 可以在更高的压力和温度下运行，约 160 个大气压和约 315 摄氏度。这提供了比 BWR 更高的卡诺效率，但反应堆结构更复杂，建造成本也更高。美国大多数反应堆都是压水堆。

Boiling Water Reactor

Pressurized Water Reactor

Liquid-Metal Fast-Breeder Reactor