RIO DE JANEIRO, Aug 25 (Reuters) - A Petrobras refinery in metropolitan Rio de Janeiro sprang a leak in one of its only operating steam boiler units, the president of the union responsible for workers at the plant told Reuters on Monday.
The leak in a boiler linked to the Duque de Caxias Refinery's U-1320 unit was discovered on Sunday. The boiler is part of a system that helps provide heat and other energy for the plant, Simao Zanardi, president of the union, known as Sindipetro Caxias, said.
The refinery, commonly known as REDUC, is Brazil's fourth-largest and recently processed nearly 248,000 barrels of oil a day. With another boiler out of service for scheduled maintenance, the U-1320 system is one of the only major sources of heat energy for REDUC, the union said.
Officials at Petroleo Brasileiro SA, as Petrobras is formally known, were not immediately available for comment.
Union stewards plan to talk with Petrobras management and Brazilian labor-law prosecutors at REDUC about the leaks and are asking that the U-1320 unit be shut while the leak is repaired, Zanardi said.
Union officials have been complaining about a series of accidents at Petrobras refineries as the Rio de Janeiro-based company struggles to boost domestic production of fuels such as gasoline and diesel in an effort to limit imports. Last week a worker died of burns suffered at a Petrobras refinery in Manaus.
On Sunday REDUC was also required to evacuate workers at the boiler undergoing maintenance, the union said. That boiler also provides energy to REDUC as well as helping treat the plant's carbon monoxide waste.
Brazil's labor-law prosecutors office in Brasilia was not immediately able to confirm if its officials were on site at REDUC, but said that no new cases have been formally launched either on Sunday or Monday.
Brazil's government, which controls Petrobras, requires the company to sell gasoline in Brazil at about 10 percent less than world prices and diesel at about 4 percent less. This has exacerbated losses on imports.
To limit the need for imports Petrobras has been running its refineries at about 98 percent of capacity and increasing the amount of fuel its 13 existing Brazilian refineries can process. This has put pressure on equipment and made some operations unsafe, the union says.
Petrobras preferred shares, the company's most-traded class of stock, rose 3.11 percent in early afternoon trading in Sao Paulo, to 21.57 reais, on track for its highest close in more than two years. (Reporting by Jeb Blount; Editing by David Gregorio)