GORLEBEN, Germany About 40 Greenpeace activists broke into a nuclear waste storage center Friday where they unfurled a banner calling on France to cancel plans to ship nuclear waste to the site, a spokesman for the environmental group said as quoted by AFP. He said about 15 activists climbed the 30-meter-high (90-foot) surveillance tower at the center in Gorleben, northern Germany, where they hung a banner saying "Stop the Castor," referring to the nuclear waste containers.