Senescence – growing old; aging

Ethan Allen‘s was generation-old technology. Her S5W reactor was too dated for much more use. Nuclear radiation had bombarded the metal vessel and its internal fittings with many billions of neutrons. As recent examination of test strips had revealed, over time the character of the metal had changed, becoming dangerously brittle. The system had at most another three years of useful life. A new reactor was too expensive. The Ethan Allen was doomed by her senescence.”

The Hunt for Red October, Tom Cancy