The New Age of Nuclear Power

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How HTR-10 works

 

Project director Zhang Zuoyi explains that HTR-10’s carefully designed geometry, low fuel density and small size make it inherently safe. In the event of a catastrophic cooling-system failure, the core temperature climbs to about 1,600 degrees Celsius — comfortably below the balls’ 2,000-plus-degree melting point — and then falls.

 

This unusual margin of safety isn’t merely theoretical. INET’s engineers have already done what would be unthinkable in a conventional reactor: They’ve switched off HTR-10’s helium coolant and let the reactor cool down all by itself.

 

Harnessing nuclear power

 

Decisions made in the earliest days of the atomic age determined the design of today’s nuclear power plants. In 1943, scientists at the University of Chicago set off the first man-made nuclear chain reaction in a pile of uranium blocks. Chemist Farrington Daniels soon joined the effort of harnessing atomic power; however his focus was on using the power for cheap, clean electricity rather than bombs. He proposed a reactor containing enriched uranium “pebbles” — a design similar to HTR-10.

 

Before Daniels’ reactor could be built, though, Hyman Rickover—with funding from the U.S. Navy for its development — presented the competing idea of a rod-fueled, watercooled reactor to power submarines. The pebble-bed idea fell by the wayside.

 

By the mid-1950s, civilian nuclear power was a hot topic. Edward Teller, father of the hydrogen bomb, argued that reactors must be “inherently safe.” He proposed a practical test: If you couldn’t pull out every control rod without causing a meltdown, the design was inadequate.

 

But Teller’s advice was ignored. Instead of pursuing inherent safety, the budding civilian nuclear industry followed Rickover into fuel rods.

 

In the following decades, however, scientists in faraway places continued to pursue the goal of developing a better reactor. One location was China.

Vocabulary Focus

inherently (adv) [in5hiErEntli] existing as a natural or basic part of something

catastrophic (adj) [7kAtE5strCfik] relating to a sudden event that causes very great trouble or destruction

fall by the wayside (idiom) to no longer be active or considered important; to give up or be discarded

budding (adj) [5bQdiN] growing or developing

 

Specialized Terms

chain reaction (n) 连锁反应 a chemical reaction in which each change causes another, or a set of related events in which each event causes the next one

核能发电新时代

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HTR-10 运作原理

工程主持人张作义解释，精心设计的几何形状、低燃料密度及小体积，使 HTR-10 高温反应堆本质上很安全。若发生灾难性的冷却系统故障，核心温度将上升至约摄氏1600度，远低于球体2000多度的熔点，温度并会随即下降。

这种罕见的安全边际值不仅是理论而已。核能与新能源技术研究院的工程师已做出在传统反应堆难以想象实现的事：他们关闭 HTR-10 的氦气冷却剂，让反应堆自行冷却。

 

利用核能发电

原子时代早期的决策左右了今日核能发电厂的设计。美国芝加哥大学的科学家于1943年利用一堆铀块，引发了第一宗人造核子连锁反应。化学家法凌顿·丹尼尔斯不久便加入到研究利用核能的行列中，但他着重于利用核能产生廉价、无污染的电力，而非制造核弹。丹尼尔斯提出制造一种含有浓缩铀“卵石”的反应堆的构想，这是个类似 HTR-10 的设计。

丹尼尔斯的反应堆制造完成之前，美国海运将领海曼·李科佛凭借美国海军的资助，提出了另一个与丹尼尔斯竞争的构想，就是利用燃料棒及水冷却的反应堆来提供潜水艇动力。之前的卵石床实验反应堆的构想顿时失去重要性。

20世纪50年代中期，民间核能发电是个热门话题。“氢弹之父”爱德华·泰勒认为反应堆应具备“本质上很安全”的条件。他提出一个合乎实际的测试方式：若你将控制杆一一拔出，却有可能导致核电厂反应堆核心熔毁时，该设计便有不足之处。

但是泰勒的建议没有被采纳。当时处于萌芽期的民间核能发电业不愿追求反应堆本质上的安全性，反倒采用了李科佛使用燃料棒的构想。

然而，在随后数十年里，远离美国等地的科学家们为了研发出更好的反应堆，继续不断地努力，其中一个地方便是中国。