Just to be clear, ANO and Pilgrim are the worst operating nuclear power plants in the USA. There are owned by Entergy. Where is your dignity?
Findings
Introduction. The inspectors reviewed a Green self-revealing non-cited violation of 10 CFR Part 50, Appendix B, Criterion V, “Instructions, Procedures, & Drawings,” for failure to follow the instructions in the chemical volume control system charging pump pulsation dampener bladder charging procedure. Specifically, the licensee used a gas cylinder containing argon, carbon dioxide, and oxygen rather than a pure nitrogen cylinder to charge the dampener. The gas leaked into the reactor coolant system and was subsequently activated by neutrons. Reactor coolant system activity significantly increased, which elevated dose rates in the auxiliary building.
It's the absence of a fix it quickly philosophy. The longer you got a mechanical defect in a system with degraded safety culture the greater the chances of a bigger problem popping up.Description. The Unit 2 chemical volume control system charging pumps have suction and discharge dampeners to reduce pressure pulsations caused by these positive displacement pumps. These dampeners are an accumulator tank with a nitrogen filled bladder. Nitrogen leakage through the bladder can result in the nitrogen entrainment in the water, which is pumped into the reactor coolant system. The licensee had been aware
of leakage from the dampeners and had implemented quarterly preventative maintenance tasks to check the pressure and fill the dampeners with nitrogen, if necessary.
On July 31, 2015, a reactor coolant sample indicated a rising trend in argon-41. argon-41 is a radioactive isotope of argon that is created when argon-40 in reactor coolant passes through the reactor and becomes irradiated. It undergoes decay, giving off a high-energy beta particle, increasing dose rates in the plant. A failure mode analysis team investigated the possible causes and identified the most likely cause to be a leaking charging pump dampener bladder filled with the incorrect gas.
On September 3, 2015, the licensee performed gas chromatograph sampling on the 2P-36C charging pump suction and discharge dampeners. Although the test equipment cannot test for percent argon content, the test determined that the suction dampener only had a 14.4 percent nitrogen content. The discharge dampener only had a 15.4 percent nitrogen content. If the dampeners were charged with nitrogen as expected, the content would be expected to be over 90 percent nitrogen. The licensee recharged the pulsation dampener with pure nitrogen, and dose rates in the plant returned to normal.
The addition and subsequent activation of argon caused the reactor coolant activity to increase by a factor of three over a period of two months. This increased the dose rates in the vicinity of piping associated with the chemical and volume control system, increasing dose to operators and radwaste personnel.
The licensee performed a cause analysis and determined that a human performance error caused the wrong gas to be used. Plant maintenance mechanics had performed pulsation dampener preventative maintenance on July 28, 2015. The mechanics retrieved a pressure gauge from the hot machine shop and went to the compressed gas cylinder storage rack. The mechanics measured pressure in the cylinders and chose the first cylinder that contained sufficient gas. The mechanics then proceeded to 2P-36C charging pump dampener fill connection, connected the cylinder to the charging header, and recharged the pulsation dampeners.
All of the gas cylinders in this storage location were the same color, and the labelling appeared similar unless read carefully. The mechanics failed to check the label on the gas cylinder to ensure that they chose a nitrogen bottle, and they incorrectly chose the single cylinder that contained a mixture of carbon dioxide, oxygen, and argon.
The licensee revised the procedure to require independent verification of the gas prior to charging pulsation dampeners.
Chemistry samples confirmed there was no change in oxygen content in the reactor coolant.
Analysis. The failure to follow the pulsation dampener charging procedure, which resulted in increased reactor coolant system activity and elevated dose rates in the auxiliary building, was a performance deficiency. The performance deficiency is more than minor because it was associated with the plant facilities/equipment attribute of the Occupational Radiation Safety Cornerstone and adversely affected the cornerstone objective to ensure the adequate protection of the worker health and safety from exposure to radiation from radioactive material during routine civilian nuclear reactor operation. Specifically, charging argon into a pulsation dampener with a known bladder leak resulted in an increase in reactor coolant activity, causing elevated dose rates in several plant areas. Using NRC Inspection Manual Chapter 0609 Appendix, C, “Occupational Radiation Safety Significance Determination Process,” issued August 19, 2008, the inspectors determined that the finding was of very low safety significance (Green) because it did not involve ALARA planning or work controls, did not involve an overexposure, did not have a substantial potential to be an overexposure, and the ability to assess dose was not compromised. The inspectors determined this finding had a cross-cutting aspect in the human performance area, Avoid Complacency, because the plant maintenance mechanics failed to implement appropriate error reduction tools such as self-checking and peer-checking. [H.12]
Enforcement. Title 10 CFR Part 50, Appendix B, Criterion V, “Instruction, Procedures, & Drawings,” states that “Activities affecting quality shall be prescribed by documented instructions, procedures, or drawings, of a type appropriate to the circumstances and shall be accomplished in accordance with these instructions, procedures, or drawings. Instructions, procedures, or drawings shall include appropriate quantitative or qualitative acceptance criteria for determining that important activities have been satisfactorily accomplished.” Contrary to the above, on July 28, 2015, the licensee failed to accomplish an activity affecting quality in accordance with the procedure. Specifically, the licensee failed to charge a charging pump pulsation dampener, an activity affecting quality, with nitrogen as required by quality Procedure OP-2411.066, “Charging Pump Dampener Bladder 2M-115A, B, C and 2M-116A, B, C Charging, Checking and Depressurization,” Revision 5, Attachment 3, Supplement 1. Step 1.3 of this procedure required that nitrogen be connected to the charging pump pulsation dampener supply valve during the charging process, but a bottle with a mix of gases including argon was used instead. The error resulted in a significant increase in reactor coolant activity, with a resulting increase in dose rates in various areas of the plant. As corrective action, the licensee recharged the dampener with pure nitrogen and degassed the reactor coolant system to reduce dose rates in the plant. This violation is being treated as a non-cited violation (NCV), consistent with Section 2.3.2.a of the Enforcement Policy because it was of very low safety significance (Green) and it was entered into the licensee’s corrective action program as Condition Report ANO-2-CR-2015-02576: NCV 05000368/2015003-01, “Failure to Follow Procedure Results in Increased Reactor Coolant Activity.”
***"On August 18, 2015, the licensee identified an adverse trend in unsecured doors, as documented in Condition Report CR-ANO-C-2015-03229. Specifically, the condition report documented that 15 condition reports had been written since May 1, 2015, for fire or high energy line break doors found open and unattended. The licensee addressed this trend by conducting a personal interface campaign at the plant entry area. As persons entered the station, managers stopped them, discussed the importance of barriers, and handed them a one page document with further information on why barriers are important to safety. In addition, departmental managers were given an action to develop a plan to verify or improve employee behaviors. Following these actions, two more condition reports identified doors that had been left open. Station management held a stand down on September 28, 2015, with all station employees to ensure that they understood the importance of door design and configuration.'
The inspectors found that the station had appropriately identified the adverse trend in regards to station behaviors, but had failed to document an adverse trend in the number of documented door deficiencies. In the past year, 31 condition reports documented deficient conditions on doors required for security, fire, high energy line break or flooding. Although the licensee failed to identify the trend, the inspectors determined that the licensee was addressing the conditions appropriately in the work management system. The licensee documented the observation in Condition Reports CR-ANO-C-2015-03972 and CR-ANO-C-2015-03973.This whole thing is frightening as hell below. Basically defective breakers and buses interacting with a roof leak....plus the issue gets lost in the bureaucratic document system. Instead of bureaucracies and documentation systems shining a light on problems early, it digs a big hole and buries the problems. Roof leaks are prime evidence of a severe safety culture problem. How long was the roof leak and why didn't the NRC step in before it damaged the bus and breaker?
Another non sited violation to their buddies ...
***Introduction. The inspectors reviewed a self-revealing violation of 10 CFR Part 50, Appendix B, Criterion XVI, “Corrective Action,” for the failure to promptly identify and correct conditions adverse to quality. Specifically, the licensee failed to promptly replace short bus stabs with longer bus stabs in six safety-related motor control centers (MCCs) following a 2007 motor control center fault.
Description.
On April 21, 2015, non-safety MCC 2B-35 experienced a fault which melted bus bars and caused the feeder breaker to the MCC to open to isolate the fault, de-energizing multiple non-vital loads in the turbine building. Subsequent inspection and analysis determined that the fault was caused by a high resistance connection between the breaker for turbine building recirculation fan and the associated bus bars. Contributing to this condition, the licensee observed indications that water had dripped onto the bus bars from above from turbine building roof leaks. This event led the licensee to review a previous similar event and to assess the corrective actions for that event.
In October 2007, a fault had occurred in a Unit 2 motor control center when starting a charging pump, which tripped the motor control center feeder breaker and secured power to all the loads supplied by that motor control center. The licensee documented in Condition Report CR-ANO-2-2007-01512 that the cause of the fault was “limited physical stab engagement on bus”. The limited contact area between the breaker stabs and the bus bars was determined to be marginal for the current needed to run the charging
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