Grand Gulf Nuclear Station stays closed as feds inspect (Oct 31, 2016)
Entergy shut the plant down on Sept. 8 to repair a water cooling pump. On Sept. 23 after work on the pump was completed, according to an NRC release, workers discovered that "misalignment of valves" had rendered a backup heat removal system unavailable. The plant is required to have that alternate system available when one of the plant's two heat removal systems is out of service.It is felt this plant is one mistake away from permanent shutdown based on it being non competitive.
"The following day, when preparing to restart the reactor, control room operators caused an unexpected increase in reactor vessel water level due to a misalignment of valves," the NRC release said.
During a high intensify outage just prior to a start-up, the operators have to hand check manual and remote operated valves. For maintenance and testing, they have to manipulate many thousands of valves during the outage. Its too complicated to keep track of valve position from job to job and the error rate is too high. It eats up man power. So just prior to the startup, the ops trogs carry around the plant a valve line sheet paper with all the valves needing to check the valve positon. Your check the valve position and realign the valves to the require position. It really is a high skill job to do this right. It could be a system one sheet of paper with list of valves in one room or fifty sheets of paper on a clip board with valves all over the plant.
It's common practice throughout the industry, the trogs "radio" (the lingo and the phrase began in the Navy)these valve lineups. Its really falsification of paperwork. The majority of the list of valves are infrequently operated or almost never operated valves. So you just check off(mark down on paper) on valve list the correct valve position without actually visually looking or touching the valve. I radio'd many valve line-up sheets. Never got caught once for doing this. You can't be a dummy radioing valve line-up list. It's a high intelligence operation to do it right.
(the assumption here is everyone are not radioing)A new employee on shift is just given a valve list(easy one)and told to do the valve lineup. You have to understand the system to do this right. It usually takes the new guy hours complete the "valve lineup". He has to hunt for the location of the valves in a humongous plant. An experienced employees could do this very quickly because he knows location of that tiny instrumentation root valve from memory. You get a good reputation in the control room if you can do valve lineups quickly and not get into any issues. Its the sliding slope of corruption (look up frog boiling)...
The plant upon startup has a procedure...basically another check-off list. It dictates how you startup the plant in a approved and standard manner across all shifts. You have a check off that all valve lineups are complete in the plant startup procedure. If all valve lineups are not complete, then you can't startup the plant. The NRC doesn't enforce paperwork falsification because it is deemed as safety insignificant.
(more about safety significance)
Cooper today
Commission will inspect PPD's response to error at nuclear plantThe federal Nuclear Regulatory Commission on March 13 will begin a special inspection of the Nebraska Public Power District’s response to an error at its nuclear plant that may have taken a heat-removal system out of operation for about four months.NPPD on Feb. 5 found that two valves — which had been closed during a scheduled refueling outage on Oct. 7 — were not reopened once the Cooper Nuclear Station was brought back online. The plant is near Brownville in southeast Nebraska.The heat-removal system was backed up by a second system, but the NRC will also look into whether both were inoperable for about 72 hours when the other system was offline for maintenance.Such systems are “used to mitigate the effects of a variety of accidents,” the NRC said.Drew Niehaus, a Cooper spokesman, said nothing went wrong as a result of the valves not being reopened and no equipment was damaged.The finding prompted the “special inspection” by two NRC inspectors. Special inspections are the least aggressive of NRC examinations of problems at plants, with “augmented” inspections being more rigorous and “incident” inspections being the most aggressive.“This special inspection will help us better understand the circumstances that led to the operator error,” said Kriss Kennedy, the NRC’s Region IV administrator.
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