Energy Biz - September/October 2008 - (Page 98) » technoloGy Frontier camera triggers plant Shutdown SAFEgUARdiNg NUCLEAR CONTROLS By dARRELL dELAMAidE if you Think They’re kidding when they tell airplane passengers to turn off cell phones and other electronic equipment for takeoffs and landings, think again. Radio frequency energy from a digital camera maintenance workers were using to photograph the control panel shut down Indian Point No. 2 in Westchester County, N.Y. last March. Entergy, the operator of the plant, reported the incident to the Nuclear Regulatory Commission. In June, following local press reports, NRC confirmed that radio frequencies from a camera that was too close to a control panel somehow affected a boiler feed pump that provides water to four steam generators. The malfunction led to a drop in water levels that forced the company to shut down the plant two days ahead of a scheduled refueling. No radiation was released. Entergy has since banned all digital cameras, cell phones, BlackBerries and other types of electronic equipment from control rooms in its plants and NRC promised to notify the 103 other nuclear power plants in the country about the incident. NRC was quick to add that no remote signals could have had the same effect. “Somebody driving down the road with a radio transmitter is not going to be able to cause the same thing,” says Neil Sheehan, an NRC spokesman. The thickness of the walls is designed among other things to shield the facility from this kind of interference. In this case, it was the proximity of the camera, inside the walls, that was decisive. Nonetheless, the unexpected fragility of these mammoth power plants is likely to add to concern about their vulnerability. Andrew Spano, Westchester County executive, told local television news reporters he wanted the NRC to investigate. “We get assurances all the time that it’s absolutely safe, etcetera, and then something like this pops up,” he said in an interview with WABC-TV. “I mean, this is a camera.” A digital camera was the culprit in an earlier incident at the Haddam Neck nuclear plant in Connecticut in 1997, only this time it was the camera flash that was blamed for releasing Halon gas as photos were being taken of the fire detection system panel for a training manual. The NRC’s information notice captured some of the September/October 2008 drama in this incident after two camera flashes: “Within 3 to 5 seconds of the second flash, Halon discharged from the overhead nozzles…. It was characterized by a loud roar, fog, and significant air turbulence. The discharge scattered loose papers around the control room and dislodged several ceiling tiles, support frame pieces, and lighting fixture plexiglass covers.” The control room was quickly evacuated but re-manned within an hour. What is worrying about these incidents, critics say, is that operators of the plants seem to be unaware that these things can happen. An engineer’s report from Entergy to the NRC regarding the Indian Point incident said the control room staff was “not aware that just having a digital camera turned on in close proximity to other digital equipment could cause a problem.” Ignorance was also a factor in an unplanned shutdown at the Hatch nuclear power plant in Georgia in March after a software update was installed on a single computer. This time, the Southern Company technician installing the update on the plant’s business computer was aware that the computer was linked to one of the facility’s primary control systems. But he was not aware that that the software was designed to synchronize data between both networks, so that a reboot in the business system computer would force a similar reset in the control system computer. When he rebooted the updated computer, it reset the data on the control system, causing safety systems to mistakenly interpret the lack of data as a drop in water reservoirs that cool the radioactive nuclear fuel rods. So the plant’s automated safety systems triggered a shutdown. 98 E n E rgyB i z
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