Troubled power group British Energy has revealed two of its reactors in Lancashire will not return to service this year.
The Heysham 1 plant reactors were shut down on 28 October following the failure of a sea water cooling pipe.
The firm now says further pipe work means the two units are likely to remain out of action until the first quarter of 2004.
It had been hoped the reactors would have reopened by the end of last month.
The financially troubled group recently put the cost of the closure, combined with a shutdown at Sizewell B in Suffolk, at more than £50m as it has been forced to go into the electricity market to replace the lost power.
The problems were among the factors that recently led the company to ask Trade and Industry Secretary Patricia Hewitt for a £75m increase in the level of a £200m loan from the government.