Today's display cases have to be impregnable to thieves but easily accessible to those authorised to handle them.
Fordow, Iran's second enrichment facility (its main one is at Natanz) which is buried deep within a mountain and thought to be impregnable to conventional air strikes, will cease all enrichment and be turned into a physics research centre.
In addition to halting enrichment, officials said, Iran must agree to ship out its stockpiles of 20 percent uranium and to cease operations at an enrichment facility buried in a mountainside near the holy city of Qum, which Israel says could soon be impregnable to an airstrike.
"Part of the bizarre but interesting psychology of the tech boom was the sense of hubris people developed, thinking they were impregnable to losses and defeats," said Joan DiFuria, a psychotherapist who is co-founder, with Stephen Goldbart, of the Money, Meaning and Choices Institute in Kentfield, Calif., north of San Francisco.
She planned to take Daugavpils, but after a reconnaissance mission discovered that the city was defended by a strong garrison and was impregnable to attack by such a small force as her own unit, that plan was abandoned.
His party's support is impregnable, according to the polls.
It's easy to think of the Affordable Care Act as monolithic national policy, a federal program so big that it is impregnable and impervious to change.
A look at the four hands indicates that the contract is impregnable: South is due to lose two trump tricks and a heart.
It just goes to show that in the modern economy, no fortress is impregnable, not even Singapore's port.
"Bell Canada is impregnable".
