(UPDATE) According to Switzerland's Beobachter (in German), the cracks are along the horizontal weld of the shroud, not "top to bottom" as Mainichi describes. The core spray system was also found with cracks. (H/T Atomfritz)
More on Mühleberg Nuclear Power Plant in Switzerland, whose license to operate will be withdrawn in June 2013 by the court order (see my previous post).
Japan's Mainichi Shinbun (3/8/2012; link goes to a message board with full copy of the article) reports that the plant operator BKW Energy and the nuclear regulating agency of the Swiss government hid the discovery in 2009 of a huge crack in the core shroud inside the Reactor Pressure Vessel.
From Mainichi Shinbun article (part):
However, the local media reported in June last year in the wake of the Fukushima I Nuclear Power Plant accident that the 9-meter high stainless-steel core shroud inside the Reactor Pressure Vessel at Mühleberg Nuclear Power Plant [there is only one reactor] had a crack from top to bottom. The federal nuclear safety regulation agency denied the risk, saying "Even if there is a crack, [the shroud] meets the safety standard, and there is no problem."
Anti-nuclear groups criticized the comment, saying "The core shroud is an very important structure that surrounds nuclear fuel rods and control rods. The damage may cause the fuel rods to shift." The crack had been discovered in 2009 but it was not disclosed. The anti-nuclear group(s?) filed a suit in the Federal Administrative Court demanding the withdrawal of the operation license issued by the federal government in 2009. With the ruling [on March 7], the Federal Administrative Court upheld the complaint from the group.
The crack in the core shroud was found in 2009, in the same year that the government granted the operator an open-ended (indefinite) operation license. I wonder which came first.
Mainichi also reports that BKW Energy plans to appeal to the Swiss supreme court.