The Nuclear Regulatory Commission (NRC) recently released Oyster Creek Generating Station's annual assessment, which noted nine findings of low significance, many of which were the result of human performance or error.
“More often than not, in every kind of human performance-related issue, they are self-identified,” said Suzanne D’Ambrosio, spokesperson for Oyster Creek.
Each of the findings was ranked “green” by the NRC, which means it was “more than minor.” Four out of the nine findings were marked "human performance" while the others dealt with failure to follow protocols.
For example, inspectors found that Exelon, the owner and operator of the plant, measured pressure baseline data for service water pumps from three points according to their procedure when the American Society of Mechanical Engineers requires data to be taken at five points.
When an error like this occurs and an employee realizes something happened out of a procedure, they immediately take the steps to address the situation, D’Ambrosio said.
“What’s also done in incidences, we take a look at what happened after the fact and look to see how we can make sure that that type of issue never happens again,” she said. “Anytime anything happens, we always stop, take a look and examine the cause for what happened and why it happened and take steps to see that it never happens again.”
Two of the findings dealt with emergency preparedness and security. Exelon modified its Emergency Action Level Basis company-wide. The change allowed Exelon to notify the NRC of an event such as a fire within 15 minutes of the occurrence while the NRC wishes to be notified upon first indication, said Jo Ambrosini, Oyster Creek Resident Inspector.
“This came out of the Midwest,” Ambrosini said. “It wasn’t that something necessarily happened. It wouldn’t have been an actual security problem. It’s a potential weakness. If there was an actual event, it would have been a higher (significance) level.”
Ambrosini’s job entails a two-pronged approach — confirming data and finding faults, she said.
“Exelon ideally likes to catch (an error) with the workers,” she said. “We provide an extra layer of protection.”
There were no performance indicators or inspection findings in 2011 that were greater than green, which signifies very low safety significance, the assessment states.
Ambrosini said that in one finding, Exelon did not make an accurate immediate determination of an inoperable emergency service water pump discharge piping.
“It’s best to catch that at a green level,” Ambrosini said.
Even with emergency preparedness, a finding could be “relatively insignificant,” D’Ambrosio said.
“It could be something in the wording, something in paperwork, a tiny step that would have had no threat on plant safety or protecting the public,” she said. “Findings aren’t always something that would be something so significant that they would cause an effect.”
The NRC follows up with the plant to ensure that each of the issues have been addressed and placed in a corrective action plan, Neil Sheehan of the NRC said. If that's not the case, the NRC can pursue additional enforcement action.
Each of the findings has been addressed, D’Ambrosio said.
“The report you see is an annual report; things that happened over the course of the year. To us it’s a snapshot in time,” she said. “It’s an evolving industry and technology. We need to stay ahead of it.”
Even though the power plant boasts only green findings, “green doesn’t mean excellent,” said Janet Tauro of Grandmothers, Mothers and More (GRAMMES).
“The problem is that you’re dealing with a technology with such deadly consequences when something goes wrong,” she said. “With nuclear, you cannot have flaws. But humans are not perfect. You will have performance problems.”
GRAMMES has always commended the Oyster Creek workforce, Tauro said.
“They are dealing with this terrible plant that has all these safety issues,” she said. “Thank God they’ve done the job they’ve done so far.”
The problem isn’t with the employees; it’s with the structure, which is the oldest operating nuclear plant in the country.
“Those human performance flaws are extremely serious because you’re dealing with a plant that’s on its last legs and has a history of safety problems and a corroding containment,” she said. “You can’t have performance issues. You have to be perfect every single day and that’s impossible.”
Below is a brief description of each finding. The annual assessment for Oyster Creek, which contains more details regarding each finding and how Exelon addressed the issues, is available on the NRC website. Current performance information for the plant can also be found on the NRC website.
Failure to Administer Post Event Fitness for Duty Testing
Exelon failed to administer post-event drug and alcohol testing as well as fatigue assessments following a “potential substantial degradation of the level of safety of the plant,” which occurred on Dec. 23, 2010. The assessments were not conducted on operators whose human error caused a reactor scram during a reactor startup.
Control Cables for Reactor Coolant Inventory Makeup Source Not Protected From Fire Damage
Exelon failed to keep the reactor coolant inventory makeup system free of fire damage in the event of a fire in a switchgear room.
Failure to Perform Acceptance Inspection of Contractor Work Results in Damage to Safety Related Instrument Cable
Exelon did not conduct a post-maintenance inspection of work done by a contractor on a main steam isolation valve. As a result, the valve underwent heat damage causing a ground on the cable and a half scram.
Tradition Enforcement Changes to EAL Basis Decreased the Effectiveness of the Plan Without Prior NRC Approval
Exelon made a modification to its Emergency Action Level Basis without notifying the NRC, specifically the amount of time allotted to alert the federal agency of an event. The change decreased the effectiveness of the emergency plan.
Failure to Make an Accurate Immediate Operability Determination
Exelon did not make an accurate immediate operability determination following the discovery of a through wall leak in the emergency service water pump.
Failure to Establish Proper Baseline Data for Service Water Pumps in Accordance with ASME Code
Exelon’s own procedures allowed operators to take differential pressure baseline data at three flow rates while the American Society of Mechanical Engineers requires data to be taken from five points.
Failure to Establish Procedures for Responding to the Loss of Control Room Annunciator
Exelon did not have written procedures for abnormal, off-normal, or alarm conditions and procedures for combating emergencies and other significant events. This finding was discovered when Exelon did not have a procedure to cope with loss of a main control room annunciators.
Details of this finding are being withheld from public disclosure since it deals with security-related information. The finding affected the Barrier Integrity Cornerstone and was related to mitigative measures to cope with losses of large areas of the plant.