Scotland's Environment Secretary has raised concerns over the decommissioning of the Dounreay nuclear site.

Roseanna Cunningham has written to the UK Government seeking assurances over the clean- up of the site on the Caithness coast.

The Scottish Environment Protection Agency (Sepa) gave a 2016 end-of-year "at risk" rating for the management of radioactive waste and a "poor" rating for the management of low level waste vaults.

The issues were highlighted in the annual report of the Nuclear Decommissioning Authority (NDA), alongside a "deterioration" in safety performance.

In a letter to UK Energy Minister Richard Harrington, Ms Cunningham said: "I would like to raise concerns that I have about performance at the Dounreay site, and seek your assurance that in its role as the lead sponsor of the Nuclear Decommissioning Authority (NDA), the UK Government is giving sufficient attention to Dounreay.

"There continues to be cause for concern in Dounreay's environmental performance, with the Scottish Environmental Protection Agency (Sepa) having to take action.

"In addition, the recently published NDA annual report presented in stark terms the lack of progress at Dounreay across a wide range of projects."

Ms Cunningham said the situation was disappointing and sits oddly with the expected loss of around 200 jobs at the site.

She added: "Local stakeholders have told me that they cannot understand why the current substantial voluntary redundancy programme is in place where there is still so much work to complete on the site.

"I would therefore ask that you give priority to securing improved performance at the Dounreay site, with continued consideration of local stakeholder views. It is vital that there is continued momentum in the safe and effective clean-up at Dounreay."

Local SNP MSP Gail Ross said she was also seriously concerned over Dounreay's environmental and safety record in the past year.

She said: "The Dounreay site is a vital employer in Caithness and North Sutherland and the effects of the redundancy scheme which the NDA has implemented has been keenly felt in both counties.

"I'm very concerned that the redundancy policy they currently have is still being pursued, despite this report stating that the site is struggling with maintaining safety and performance".

An NDA spokesman said: "Decommissioning and hazard reduction at Dounreay remain a priority for the NDA, and the contractors performing the work.

"We will respond directly to Ms Cunningham about the points she raises in her letter."

A spokesman for the UK Department for Business, Energy and Industrial Strategy (BEIS) said: "The NDA continues to monitor progress at the Dounreay site closely to ensure that it is delivering high quality work and that it remains value for money."

"BEIS will respond to the letter in due course."