They can have highly enriched uranium, meaning weapons grade.

伊朗可以拥有等同于武器级别的高浓缩铀。

When it is highly enriched, uranium can be used as a fuel for nuclear weapons.

当铀高度浓缩时，可以用作核武器的燃料。

For the past two decades, however, almost 20,000 of those Russian warheads have provided highly enriched uranium.

然而在过去的20年间，约有20,000个俄国弹头为铀浓缩提供了原料。

The UN's nuclear watchdog, the IAEA says it's asked Iran to explain the origin of highly enriched uranium particles which it discovered at an Iranian plant recently.

联合国核监督机构国际原子能机构表示，已要求伊朗解释最近在伊朗一家工厂发现的高浓缩铀粒子的来源。

By propelling a highly enriched uranium block onto another, the material becomes supercritical.

通过将高浓缩铀块推到另一个上， 材料变得超临界。

A senior Pentagon official said that the time Iran would need to make one bomb's worth of highly enriched uranium had gone from about 12 months to around 12 days.

五角大楼的一名高级官员表示，伊朗制造一枚核弹(相当于高浓缩铀)的时间已经从12个月左右缩短到12天左右。

And we do some more work, it turns out that what you require to make a nuclear bomb is highly enriched uranium or plutonium, which are very difficult materials to get.

我们又做了一些工作，事实证明，制造核弹需要的是高浓缩铀或钚， 这些材料很难获得。