A beachside nuclear reactor in Brazil leaked thousands of gallons of slightly radioactive water in May, but the public didn’t learn about the problem until the Brazilian magazine Epoca broke the news earlier this week. Most of the water leaking from the Angra reactor was contained by an emergency tank, and the plant was shut down for a week. Government officials defended their decision not to inform the public about the problem, saying the risk from the leak was never significant. But Greenpeace Brazil said the incident, and the government’s response to it, confirmed the group’s concerns about nuclear power. Earlier this year, Brazil’s Environment Ministry said more research should be done before a third reactor is built at the Angra complex, which is located about 80 miles west of Rio de Janeiro and is surrounded by rainforest. Greenpeace is seeking a moratorium on new reactors.