The Europeans have also taken a tough line this time: the agreement reached with Iran specifies no deadline, and they insist it must include all work towards enrichment.

ECONOMIST: But who is squeezing whom?

To add to their suspicions, some traces of low-enriched uranium found in Iran have yet to be explained, and may indicate more enrichment work than has been owned up to.

ECONOMIST: Filling in the gaps in Iran's nuclear story

More to the point, Russia's offer to enrich the uranium from under 5% to the almost 20% needed for the medical reactor, along with France's readiness to turn it into the needed fuel rods, mean Iran had no excuse to do the higher enrichment work itself.

ECONOMIST: Brazil, Turkey and Iran

You understand that the work you do requires your commitment and in turn you derive enrichment from the work.

FORBES: Reduce Stress by Working Longer (at What You Do Well)

The mentoring program focused not only on professional work, but also on cultural enrichment.

FORBES: Have a Mentor? How about being a Mentor?

It is very repetitive and quite hard work, but there's an enrichment and enjoyment in that also, and I'm trying to combine those two quite different feelings.

BBC: Scotland

In the remaining 2.5 hours children would work with other council staff on an "enrichment programme" of activities.

BBC: Renfrewshire teachers balloted on 'hours cut'

They include Iran's ongoing uranium enrichment program, experiments with small amounts of plutonium, and a possible program that combines work on high explosives, missiles, and uranium.

NPR: Iran Defies Security Council, Enriches Uranium