Russia is legally required to ensure that the re-enriched fuel and reprocessed waste is returned or properly disposed of, but only a small percentage of the original material gets sent back.

法律上，俄国应该确保再浓缩核燃料及后处理核废料被回收或者正确处理，但是仅有一小部分原材料被回收。

youdao

Spent fuel from NPPs is planned to be reprocessed in China to make full utilization of uranium.

废燃料的核电站计划在中国再加工，使铀的充分利用。

youdao

He said the Iranian official told the diplomats that even if Tehran accepted a big power offer of last November to export some of its enriched uranium to be reprocessed as fuel for a research reactor, the broader Iranian enrichment drive would continue.

VOA: standard.2010.05.14

The MOX plant is due to start producing reprocessed fuel for use in civilian reactors in 2017 or 2018.

FORBES: Japanese Official: Most Dangerous Reactor May Have Ruptured, Leaking Radiation

Existing stocks, former nukes and reprocessed fuel provide the rest.

ECONOMIST: Uranium

They were working in Reactor No. 3 which is of particular concern because it is the only unit to use MOX fuel, which is reprocessed spent fuel mixed with plutonium.

FORBES: The Japanese Nuclear Power Crisis Deepens