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Nuclear plants need to watch the radiation they produce. It is supposed to stay in the plant and not escape. That is what monitors do. They also have to be calibrated so you know what you are reading.

A failure to periodically calibrate radiation monitoring equipment at Entergy Louisiana’s Waterford 3 nuclear power plant in Killona has earned the company a verbal slap on the wrist from the Nuclear Regulatory Commission. NRC officials listed the issue, which has been ongoing since 2006, as a “Green Non-Cited Violation” in a Feb. 8 letter to the utility. The federal agency completed an inspection of the reactor complex late last year; despite the violation, it did not recommend any fines for Entergy. The problem is of a “very low safety significance,” but is “more than minor” because it doesn’t jibe with NRC rules that require plants to adequately protect their workers from radiation exposure, NRC officials said. Inspectors also found no actual instances of radiation overexposure, a finding Entergy officials highlighted in a Tuesday statement. “The NRC determined there was no overexposure and there was no potential for an overexposure related to this issue,” said Michael Bowling, a spokesman for Entergy Operations. “No equipment has been improperly calibrated in a way that would allow our employees to receive improper radiation exposure.”

Nuclear is one of the options noted for helping us get away from oil based fuels. With the state wanting heavy industry using electricity we need all the sources we have to generate that power.

But the failure to keep the monitors fine-tuned might very well have interfered with Entergy’s ability to keep track of radiation issues, said David Lochbaum, a nuclear safety expert and former nuclear safety director at the Union of Concerned Scientists. “The in-plant monitors serve to warn operators about degrading conditions,” he said. “For example, if the seal on a pump starts to leak, radioactivity in the leaked water may cause an area radiation monitor to alarm. The alarm results in workers investigating to determine if the condition can be tolerated or needs to be fixed. Improper calibration could result in such alarms not being sounded as early as intended.” Lochbaum agreed that the chance of worker exposure was slim, in part because the monitors in question do not have a history of getting too far out of calibration, based on inspections of past NRC records on calibration problems. “Having said that, there’s little excuse for this violation,” he said. “Failing to properly justify the longer calibration intervals meant that luck was playing a bigger and bigger role than skill. And luck is an unreliable nuclear safety barrier.”

The emphasis on reporting and calibration means that it is fairly easy to note when a problem occurs.

The NRC report said that beginning in 2006, the reactor staff began increasing the time between routine calibrations of 41 monitors used to measure radiation doses in various areas, radiation in liquid or gaseous effluents released from the plant and radiation related to the plant’s operating processes. Some of the monitors were changed from three-year recalibration schedules to nearly seven years, with a few extended to nine years. Some monitors requiring recalibration every 18 months were extended to three and five years. The inspectors found that plant officials had identified the issue four months before the inspection. Still, only nine of 41 radiation monitors had been recalibrated, and only one of those had been returned to its proper calibration schedule by the time inspectors visited the site. “Additionally, 29 of the 41 radiation monitors are still past due on their required calibration frequencies,” the inspection report said. “There is still no justification for the current frequencies.” Entergy has conducted an “adverse condition analysis” of the calibration issue, and added it to the company’s ongoing correctaive action program, the inspection report said.

These seem to me to be unwarranted extensions of calibration made to make life easier for the workers. That should not have been done.

Bad calibration at nuclear plant
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