It's 50 years since the start of operations at the Magnox reprocessing plant at Sellafield in Cumbria.
The plant opened in 1964 and to date, it has reprocessed 52 thousand tonnes of radioactive waste from Magnox power stations in the UK.
Thousands of people have worked there, it now employs around 400.
To mark the facility's 50th birthday, 50 former workers were invited along, including one engineer who was there on the very first day it opened.
Our cameras were allowed in for the first time in half a century. Matthew Taylor reports.
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Emma Jesson brings you Sunday night's forecast
Wet and windy spells, interspersed with drier interludes this week. Wintry showers and variable temperatures. Gales and a weather warning
Wetter in the west, cloudy but direr further east. Milder than of late, but blustery