So once the pebble is depleted a fresh pebble can be put it in or it can be re-circulated back in the reactor if its burn-up isn't all used up or the fuel isn't all used up.

所以，一旦球体被分离了，新的球体能够,放进去或者它能够在计算回反应堆里,如果它燃烧完了，但没有用完，或者燃料,没有全部用完。

youdao

There will be a self-ignition of the UDMH and if it does not all burn up, it will be so dispersed there will not be a critical concentration.

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