fissile core

基本解释

They compress the fissile core, or pit, of the warhead until it reaches critical mass.
该技术可以将裂变核心或者弹芯压缩至临界质量。
plutonium can be extracted from nuclear wastes and expensively reused in special sorts of fuel, but it can also be fashioned into the fissile core of a weapon.
钚可以从核废料提取，并可作为某种昂贵燃料重新加以利用。然而钚也可以加工成武器中用于核裂变的核心部件。
Yet it is openly working on missiles that could deliver one and on the techniques that could produce sufficiently enriched uranium or else plutonium for a weapon’s fissile core.
但是伊朗公开研制可以运载核爆的导弹，从技术上来讲，伊朗能够生产出足够多的浓缩铀或者钚来完成武器所需的核裂变。

Uranium enrichment is a process which makes nuclear fuel but can also be diverted to produce the fissile core of atomic bombs.
CENTERFORSECURITYPOLICY: Tehran threat in the US' backyard
Yet it is openly working on missiles that could deliver one and on the techniques that could produce sufficiently enriched uranium or else plutonium for a weapon's fissile core.
ECONOMIST: Proliferation from North Korea and Iran