Work is under way to clear rubble at the site of the collapsed Didcot power station where the bodies of three workers still remain missing.
The site's owners, energy giant RWE, said it was going to be "a long process" to remove debris in a carefully-executed operation.
Officials from the Health and Safety Executive (HSE) and Thames Valley Police are monitoring progress at the plant in Oxfordshire.
Following the deployment of large equipment and workmen at the site, an RWE spokesman said: "They will be carefully working their way in. It's going to be a long process."
Demolition workers Ken Cresswell, 57, and John Shaw, 61, both from Rotherham, South Yorkshire, and Chris Huxtable, from Swansea, remain missing following the collapse on February 23.
The funeral has been held of victim Mick Collings, 53, who lived in Brotton, Cleveland. Bikers from around the country attended the service for the keen motorcyclist.
The HSE said in a statement this week that the priority was to recover the missing men from the site so that they could be returned to their families.