Wylfa Newydd developer Horizon Nuclear Power has posted a £1.6bn loss after halting its nuclear project on Anglesey.
Horizon released its latest figures this week for the year up to March 31.
It follows suspension of the scheme by parent company Hitachi in January.
That decision has seen the company take a huge impairment on the site - worth £1.5bn - according to the figures provided to Companies House.
This was alongside an operating loss of £15.8m and "non-operating expenses" of £127m.
In total there was a loss for the year of £1.68bn.
The report stated: "The suspension of most of Horizon's activities during the year triggered an impairment review with all assets being revalued at their recoverable amount based on fair value less costs of disposal.
"The asset under construction has been fully impaired due to the uncertainty over the restart of the project."
They said the intention remained to continue to try and secure opportunities to develop the Wylfa Newydd site.
But they added: "The Group cannot state with a high degree of confidence that it will be successful in this intent and, as a result, the decision has been taken to impair all assets and hold the land value at non-nuclear development value."
The business is still being classified as a "going concern" with the "Ultimate Shareholder" providing funding to meet financial obligations and liabilities of the group for at least the forthcoming 12 months(from March 31).
Horizon is pushing on with the Development Consent Order (DCO) for the nuclear plant.
They said successful completion of the DCO would help a timely restart of the Wylfa Newydd project should a new funding and financing model be agreed with the UK Government.
They said: "The group will now focus on managing its landholdings whilst working closely with the UK Government and other stakeholders and investors to bring about conditions when the programme for Wylfa Newydd could be restarted."
The group has retained a small team to continue talks with the UK Government and manage the land.
