In September 1996, workers shut down the Oyster Creek nuclear plant in New Jersey for a refueling outage. On September 17th, workers started a temporary pump to supply water to the control-rod drive (CRD) pump while performing maintenance on the system that normally provides this water. A typical CRD system is shown in the figure below. The CRD pump supplies water to insert or withdraw hydraulic pistons connected to each control rod inside the reactor core. When control rods are not being moved, the CRD pump supplies cooling water for the CRD hydraulic piston mechanisms.
The next day, operators sensed something wrong because the water level in the condensate storage tank kept falling. They investigated and found a valve in the temporary setup was open when it should have been closed. The mis-positioned valve allowed water from the condensate storage tank to flow into the discharge canal and out to Barnegat Bay. It was later calculated that approximately 133,000 gallons of radioactively contaminated water left the plant via this unmonitored and uncontrolled pathway.
The condensate storage tank at Oyster Creek holds nearly 275,000 gallons. Thus, this tank, which had continuous level indication available in the control room, lost roughly half its capacity. At midnight on September 17th, a worker filled out the daily water inventory for the plant. This accounting process should have clearly identified the loss of so much water. That’s one of the primary reasons workers perform the inventory on a daily basis. It would have this time too, except that he made a math error and his flawed analysis indicated a perfect balance to the drop.
The temporary setup required an independent verification that all valves were positioned properly. One operator placed the valves in their desired positions and a second operator verified that their positions matched the specified setup. So, either the independent verifier didn’t do such a swell job or the valve waited until after being checked and then magically re-opened itself. Valves are sneaky like that.
Whatever the reason, Oyster Creek discharged 133,000 gallons of radioactively contaminated water into the bay via an uncontrolled and unmonitored pathway.
NRC’s regulations protect against such discharges, but only when they are followed and enforced. Since this event occurred, many nuclear power plants have illegally released or leaked millions of gallons of radioactively contaminated water here, there, and everywhere. If you have ever paid a nickel as a fine for an overdue library book, you’ve paid 5¢ more than the NRC has collected for all the leaks and spills. That makes no cents.
Federal regulations only allow radioactive material to be released from nuclear plants via controlled and monitored pathways. These regulations were established to protect the public. But these measures only provide that protection when taken seriously by plant owners or the NRC. The evidence is clear that the NRC has not been taking its regulations seriously. That has to stop, and stop now.
“Fission Stories” is a weekly feature by Dave Lochbaum. For more information on nuclear power safety, see the nuclear safety section of UCS’s website and our interactive map, the Nuclear Power Information Tracker.