Odious debt is not repayable.

恶债不予偿还。

《新英汉大辞典》

Although the debt is huge, it is at bargain-basement interest rates and repayable over decades.

虽说债务庞大，但是其利率已经低得不能再低了，而且能够在数十年间偿付。

youdao

Growth will boost corporate earnings in ways that give stocks a sustainable reason to rise, make the government's debt burden repayable, and stimulate wage growth and consumer confidence.

WSJ: Review & Outlook: Japan Discovers QE Has Risks

Publicly created money without interest should be issued by governments to write down un-repayable debt and restart or stimulate stalled economies.

FORBES: Hazel Henderson: There is 21st Century Abundance Hiding in 19th Century Scarcity Politics