Last Tuesday afternoon, the High Pressure Coolant Injection system at the Unit 2 reactor at the Peach Bottom nuclear plant in Pennsylvania was declared inoperable. The problem was discovered during routine testing.
The Unit 2 reactor is the General Electric Mark 1 design, the same model that malfunctioned so badly in Japan. Peach Bottom Unit 2 went online in 1973, and has been granted a twenty-year license extension by the Nuclear Regulatory Commission.
At the very minimum, the lesson we need to learn from Fukushima is that the GE Mark 1 reactor can and does malfunction when it ages. There are 23 of these reactors currently in use in the United States, and 18 of them have been given license extensions. These reactors should be shut down until a thorough review of the Japanese disaster can be completed.