A small fire at Aberthaw Power Station was caused by sparks from scrap material during demolition work, it's been confirmed.
South Wales Fire and Rescue Service (SWFRS) said four crews were sent to the scene at around 9.55am on Friday morning.
A spokesperson said the fire was the result of "a large pile of scrap material" and crews took around two hours to bring it control.
Black smoke was spotted around the area but CCR Energy said there was "no cause for concern" and no wider risk had been identified.
A spokesperson for the site's owners said: "A small fire developed on site, but it has been well controlled, and the fire service is currently on site managing the situation. The incident is fully under control, and we expect it to be completely resolved shortly."
"Residents in the area may notice some black smoke, but we would like to reassure you - and ask that you reassure any residents who contact you - that there is no cause for concern. The incident is contained, and no wider risk has been identified."
A Fire Service spokesperson said: "The building is under demolition, and the fire is as a result of a large pile of scrap material."
"Four crews and appliances from Barry, Llantwit Major and Penarth stations attended - in addition to a water bowser - to help on-site crews to extinguish the fire. The stop message was given at 12.10."
St Athan Community Council said the fire was "caused by sparks igniting felt material" and "the incident was swiftly brought under control".
They added: "We extend our sincere thanks to everyone who responded promptly and effectively to this issue."
Demolition work is continuing at the former coal fired power station where the Cardiff Capital Region - a group of ten local councils in South East Wales - has earmarked a green energy hub.

Post Office Seeks New Operator in Dinas Powys as Village Faces Loss of Its Last Branch
Gardening team praised after helping police clear fallen tree near St Brides Major
Specsavers calls on children in Barry to design Wales Deaf Rugby World Cup shirts
Whitmore High Named One of UK’s Best Workplaces for Development
Steel Signing Marks Major Milestone in St Richard Gwyn School Redevelopment
Two Rescues in Record Heat as Volunteer Teams Respond to Afternoon Emergencies
Police find evidence of a large-scale cannabis cultivation at Riverside Place property fire
Network Rail confirm closure of Brookside level crossing in Dinas Powys
Police given powers to ask people to leave Comeston Lakes Country Park
Planned children’s role play centre could be given the go-ahead by Vale Council
Marie Curie Garden Fayre deemed huge success
Council seeks views on Future of Colcot Sports Centre and Buttrills Playing Fields
First Minister quizzed on further devolution, budget decisions, and misinformation in FMQs
Extreme heat leads to changes to services and closures
Severe Heat Warning Set to Disrupt Rail Travel Across South Wales This Week
Communities asked to support older people across Wales during severe heat warning
Caribbean Community Wales Brings Wales‑Wide Launch to Barry This Weekend
Community Award winner calls for sanitary bins in men’s toilets after living with prostate‑cancer‑related incontinence
Cardiff Airport Backs Holiday Safety Campaign Honouring Rhoose Teenager Tom Channon