* Belgium facing tight power supply due to nuclear outages
* Grid operator says needs up to 1,700 MW additional capacity
* Says cannot rule out power rationing (Adds grid operator statement, background)
By Alissa de Carbonnel
BRUSSELS, Sept 28 (Reuters) - French gas and power group Engie said on Friday that maintenance work at its Belgian nuclear reactor Tihange 1 would end earlier than planned, which could ease concerns over tight electricity supply.
Belgium is facing an unprecedented power supply deficit ahead of winter, with only one of seven nuclear reactors operated by Engie’s Belgian unit Electrabel scheduled to have been operational in November.
The change in repair work will bring the number up to two.
Electricity grid operator Elia warned on Wednesday that Belgium was facing a tough supply situation due to the long-term outage of the reactors which accounts for 25 percent of its installed capacity.
“With just a few weeks to go before winter starts, Belgium is facing the unexpected unavailability of multiple nuclear power stations, a situation that is severely testing the balance between generation and consumption,” Elia said in a statement.
Without an additional 1,600 megawatts (MW) to 1,700 MW of capacity, Elia said it cannot always guarantee security of supply without a power rationing or so-called load shedding plan.
Elia said it was talking to the Belgian government and power operators, but security of supply was not guaranteed for November, the most critical month, and it did not see solutions that could fully resolve the supply issue.
“Which is why, even if the Belgian and international markets provide us with all available capacity, we cannot yet rule out the need to activate the load-shedding plan,” Elia said.
Fears over tight supply during the winter months when demand for heating rises has push Belgian power contracts new highs.
Engie said Tihange 1 will now be shut for maintenance from Oct. 13 until Nov. 17, instead of Oct. 20 until Nov. 29. Electrabel operates two more reactors at Tihange and four at Doel, producing about half the country’s electricity.
Following the discovery of problems with the concrete in some of the plants, outages were prolonged at its Tihange 2 and 3 reactors.
Engie has faced criticism over its management of Belgium’s ageing nuclear plants, with Belgian public broadcaster RTBF running comments from an industry source accusing it of allowing degradation at its facilities.
Engie dismissed the report on Friday, saying “nuclear safety is an absolute priority” and that Electrabel invests 200 million euros ($232 million) a year in maintenance work.
The utility last week said the extended outages at Belgian plants would push its 2018 net recurring income to the low end of its 2.45 billion-2.65 billion euros forecast range.
$1 = 0.8636 euros Additional reporting by Bate Felix in Paris; Editing by Elaine Hardcastle Editing by Dale Hudson