It was reported by Mamoru Sato on his blog on July 30. I have no idea who he really is, but the bio on his blog says he was a fighter pilot in the Self Defense Air Force of Japan, and was then a high-ranking officer and the commander of the several major air force bases in Japan until he retired from the service in 1997. Checking the biography in Wiki, it looks like he is indeed what he says he is.
Mr. Sato's July 30 blogpost:
今入った情報によると、２９日大連港で中国海軍の原子力潜水艦で事故が発生し、放射能が漏れているという。周辺は軍によって厳重に閉鎖されていて、極めて危険な状況らしいという。
According to the information I just obtained, a nuclear submarine of the Chinese Navy had an accident in the port of Dalian on July 29, and there is a leak of radiation. The area is strictly closed off by the Chinese military, and the situation is said to be very dangerous.
どうせ北京政府は公表しない？だろうから、周辺国は自己防衛すべきであり、この近海で漁をしている日本漁船などは注意が必要だろう。
I doubt that the Chinese government will announce the accident. The neighboring countries should take defensive measures, and the Japanese fishing boats in the area should be careful.
もう一つ、“外国”の保険会社によると、今回の高速鉄道事故の犠牲者数は、今日現在死者２５９人、負傷者１８３人、行方不明者１５４人で、もっと被害は増える見込みだという。
One more thing. According to a "foreign" insurance company, China's high-speed train accident has 259 people dead, 183 injured, and 154 still missing. The numbers are set to increase, according to this insurance company.
現地ではいつまでも犠牲者家族の抗議が続いているし、行方不明…という語が飛び交っているので不思議に思っていたが、どうりで政府が急きょ「補償金を倍増」した理由がわかってきた。
The families of the victims continue to protest, and I've wondering about "missing" people. Now I begin to see why the Chinese government hastily doubled the compensation for the victims.
この国の「事故隠し」は我が国のそれどころではないといえる。
China's "hiding the accident" is well beyond that of Japan.
とまれ、外務省はもとより、各メディアには中国の「放射能漏れ事故」に関する情報入手を急いでほしい。中国製原発の事故は避けられないだろうから、来年の黄砂飛来時期が気にかかる。取り急ぎ情報まで！
Anyway, the Ministry of Foreign Affairs and the Japanese media should try to obtain more information about China's "nuclear leak accident". It is inevitable that a Chinese-made nuclear power plant will have an accident, and I'm concerned about the next year's "yellow sand" season. Just to let you know the news quickly.
I don't know if China's "hiding" is any worse than that of Japan, but if I see any confirming information I'll update.
After the Fukushima I nuclear accident, it dawned on many Japanese (probably for the first time) that almost entire Japan is DOWNWIND from China, who plans to have 100 nuclear power plants. And thanks to the Fukushima accident, many Japanese now know it's not the distance that matters when it comes to a nuclear power plant accident, but wind and weather.