Leak Triggers Another Shutdown at Troubled Hope Creek Nuclear
HANCOCKS BRIDGE, New Jersey, June 8, 2005 (ENS) - The Hope Creek nuclear power plant was manually shut down from full power Tuesday afternoon when a leak of steam and water from a valve near the reactor vessel increased above allowable limits.
Plant operators at Hope Creek declared an "unusual event," the lowest of four classifications used to identify events at nuclear power stations.
The plant operator Public Service Enterprise Group, or PSEG Nuclear, said, "There was no increase in release of radiation from the plant related to the event and the cause of the increased unidentified leakage inside the drywell is under investigation."
The 1,049-megawatt boiling water reactor is located on Lower Alloways Creek in Salem County, New Jersey, 18 miles southeast of the largest nearby city, Wilmington, Delaware, population 74,000.
During the incident workers at Hope Creek entered the drywell - a concrete structure surrounding the cylindrical reactor vessel - when they observed a rising level of water in the bottom of the drywell confirmed by increasing pressure of the atmosphere inside the drywell.
They found a shutdown cooling testable check valve in the failed/separated position and a 20 foot plume of steam and liquid jetting from the valve.
Workers opened a second testable check valve for shutdown cooling and took steps to close manually operated valves around the leaking valve to end the leak, nuclear safety officials said early this morning.
The plant reached cold shutdown mode at 4:55 am local time.
At the peak of the incident the water surrounding the nuclear fuel rods in the reactor vessel level fell to 30 inches lower than normal, the company said, and following the shut down the water in the reactor vessel was returned to the normal level.
"Plant personnel will now plan an entry into the drywell to conduct a thorough walk down to determine the source of the leakage and cause," PSEG said. "The unit will not be returned to service until the cause is fully understood and the appropriate actions taken."
"The source of the 20 foot plume of steam from the leaking testable check valve at Hope Creek has not been publicly reported," said nuclear engineer Dave Lochbaum with the Union of Concerned Scientists. "There are several candidate locations: cracks in the welds joining the valve to the upstream or downstream piping, drain leaks, and cracks in the valve’s body to name a few."
The Nuclear Regulatory Commission (NRC) details several smaller problems at Hope Creek in the first three months of 2005 - a control area chill water pump malfunctioned, and a degraded level control valve for a moisture separator drain tank was not evaluated and corrected by engineering staff.
In addition, an NRC report states that Hope Creek control room operators were not able to properly operate the reactor recirculation pump vibration monitoring equipment used to respond to vibration alarms.
Another NRC report says inspectors identified that PSEG did not correct a degraded condition associated with the control rod drive pump room floor access hatches and floor drains after the condition resulted in water leaking onto two core spray pumps in December 2004.
In January, NRC staff met with representatives of PSEG to go over the results of an NRC special inspection conducted at the Hope Creek nuclear power plant in response to a steam line failure and plant shutdown with complications that occurred there on October 10, 2004. Hope Creek had been operating for 57 days since restarting after that shutdown.
While the NRC says the special inspection "did not identify any serious safety violations," the agency concluded that "there were numerous indications of weaknesses in corrective actions and management efforts to establish an environment where employees are consistently willing to raise safety concerns."
The NRC said in January, "We found examples of unresolved conflicts and poor communication between management and staff, as well as underlying staff and management frustration with poor equipment reliability. The equipment issues stemmed, in part, from weaknesses in implementation of station processes such as work management and corrective action."
Although the units have been operated safely, the NRC says it is "concerned that if the work environment issues are left unaddressed, these issues could have a negative impact on plant safety, particularly as it relates to the handling of emergent equipment issues and associated operational decisionmaking."
Lochbaum says both the plant operator and the regulatory agency are at fault for these lapses. "Hope Creek has experienced more than its fair share of leaks recently. They are byproducts of years of improper maintenance by PSEG and ineffective oversight by the NRC. As a direct result, safety levels at Hope Creek are lower and operating costs are higher than is necessary," he said today.
"The NRC’s present course of inaction seems confined to merely monitoring things at Hope Creek while the sins of the past flush themselves out a leak and a break at a time, all the while crossing their fingers hoping that one of these events does not escalate into a Three Mile Island accident," Lochbaum said.
He called for the NRC to become "what the public needs – an aggressive nuclear cop on the beat."
PSEG Nuclear operates Salem Units 1 and 2, two 1,150 megawatt pressurized water reactors, on the same site in Salem County The company says Salem Unit 1 and 2 were unaffected by the events at Hope Creek and continue to operate at full power.