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Etats-Unis : Pilgrim : Une centrale gravement dégradée




14 septembre 2015


La centrale de Pilgrim (Massachussetts) exploitée par Entergy a été recalée par la NRC au rang des installations ayant subi des dégradations à répétition. Suite à la tempête Juno survenue à l’hiver 2015, la centrale a connu de nombreux problèmes qui la classent désormais parmi les pires installations nucléaires des E-U. Le 27 janvier 2015, alors que les foyers et commerces de Plymouth n’ont pas connu de coupure d’électricité, Entergy annonçait que la tempête avait déconnecté la centrale nucléaire du réseau d’électricité, forçant alors un arrêt automatique du réacteur.

Type : Fukushima 1 (BWR Mark 1) - Puissance : 2028 MWth - Première divergence : 06/1972

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Parmi les complications engendrées par l’arrêt du réacteur, le rapport d’inspection de la NRC identifiait un problème de valves de décompression (nécessaires pour refroidir le réacteur), problème qui aurait du et pu être corrigé suite à un arrêt du réacteur le 9/02/2013 et qui avait permis de détecter cette défaillance. Entergy conteste ce point arguant avoir fait le nécessaire avant l’inspection de la NRC.

Après avoir finalisé son rapport d’inspection, la NRC maintient toutefois son niveau d’alerte au niveau "blanc" c’est à dire posant un problème de sûreté de bas à modéré. La NRC étendra son évaluation de la centrale pour évaluer les causes du problème et l’ensemble des actions que l’exploitant aurait pu entreprendre pour l’éviter, mais aussi la culture de sûreté et l’ensemble des défaillances à ce jour. Le gouvernement et les élus comme le sénateur E. Markey ont également questionné la capacité d’Entergy à gérer l’installation, rappelant que la technologie de la centrale de Pilgrim est la même que celle des réacteurs de Fukushima.

Sur les dix réacteurs gérés par Entergy, seuls quatre sont classifiés dans la catégorie la plus sûre de la NRC tandis que les trois présentés dans la catégorie la moins sûre appartiennent tous à Entergy.

PILGRIM STATION : NRC puts Plymouth power plant back into nuclear doghouse

Entergy’s Pilgrim Nuclear Power Station got an unwelcome reminder last week of last winter and its effect on the plant, when the Nuclear Regulatory Commission announced it was lowering the plant’s performance rating, placing it among the worst operating facilities in the U.S.

By Frank Mand fmand@wickedlocal.com

Posted Sep. 14, 2015 at 12:00 PM

PLYMOUTH – Remember January ? Remember Juno ? The folks at Entergy certainly do.

Entergy’s Pilgrim Nuclear Power Station got an unwelcome reminder of that storm and its effect on the plant last week, as the Nuclear Regulatory Commission announced that it had finalized a “White” inspection finding issued to plant officials last spring.

Pilgrim will now be moved back into the Repetitive Degraded Cornerstone, or Column 4, of the agency’s Action Matrix, placing it among the worst operating facilities in the U.S.

Remember the story ?

Go back a scram or two, to what the NRC called a “winter storm-induced” shutdown.

While most of Plymouth’s homes and businesses stayed connected to the grid during that blizzard, Pilgrim Nuclear Power Plant did not.

Early Jan. 27, Entergy issued a release stating that “the electrical connections that Pilgrim Nuclear Power Station uses to transmit electricity to the grid were interrupted by the severe storm” triggering an automatic scram, or shutdown, of the reactor.

That automatic shutdown during winter storm Juno earned the plant a – at the time preliminary – “white” finding.

The NRC ratings of incidents go from the lowest safety significance green, to greater than green, to white, to orange and red. The inspection team’s findings for the entire Juno event included six green and one white finding.

“One of the complications during the shutdown involved the use of safety relief valves to reduce reactor vessel pressure as part of the reactor cool down process,” the NRC’s inspection report summarized at the time, and initially inspectors determined that plant-owner Entergy, “could have prevented the (safety valve) issue by identifying, evaluating and correcting a condition involving the safety relief valves after a plant shutdown on Feb, 9, 2013.”

Entergy disagreed and appealed that finding, arguing that the issues raised by the NRC had already been addressed at the plant before the inspection.

“In the four months since the Special Inspection team visited the plant following the historic Jan. 27 blizzard,” Pilgrim spokesman Lauren Burm said at the time, “the issues raised (in the report) by the NRC have all been addressed.”

Last week, however, the NRC announced that it has finalized its inspection finding and it remains “White” (low to moderate safety significance).

“In response to the plant’s change in status in the Action Matrix, the NRC will conduct a supplemental team inspection at Pilgrim to review the company’s root cause evaluation of the problem ; the company’s review of whether the issue could have extended to other equipment or systems ; and any corrective actions carried out by the company,” NRC spokesman Neil Sheehan said.

Page 2 of 3 - “The (inspection) team will also evaluate the breadth and depth of the performance deficiencies, assess the company’s evaluation of its safety culture, and independently perform a graded assessment of the plant’s safety culture,” Sheehan said.

State and elected officials also commented on this latest blemish on Pilgrim’s record, and on plant owner Entergy’s ability to effectively manage the facility.

“For decades, I have raised concerns about Pilgrim’s operations, security preparedness, the safety of the surrounding communities in the event of a nuclear accident, and the willingness of Entergy to dedicate sufficient resources to run the reactor safely,” said Sen. Edward Markey, D-Mass., said in a statement. “Pilgrim has had long-standing and repetitive safety problems and unplanned shutdowns that require an increased level of NRC oversight, especially since it is the same design as the reactors that melted down during the Fukushima nuclear disaster.

“The NRC must continue this aggressive oversight until Entergy can prove unequivocally that it has dedicated the resources, manpower and training to guarantee the safe and secure operation of this reactor.”

Markey pointed out that of the 10 reactors operated by Entergy, only four are ranked in NRC’s safest category, and all three reactors currently in NRC’s least safe Column 4 are Entergy facilities.

“I have repeatedly expressed concern that NRC has prohibited its own staff from asking Entergy to prove that it has the financial resources necessary to operate its reactor fleet safely, and I again urge the NRC to revisit its unwise decision to ignore the possibility that Entergy is systematically shortchanging safety,” Markey concluded.

Massachusetts Attorney General Margaret Healey also weighed in.

“This office has long called for increased safety measures at the Pilgrim Nuclear Power Plant, including the implementation of long-term storage solutions for spent nuclear fuel,” Healey said in a statement. “(This) decision is a disturbing development, and my primary concern is with the safety and well-being of the residents of Massachusetts, particularly those who live near Pilgrim. Entergy must act swiftly and decisively to correct these issues and restore the public’s trust in its ability to safely operate this plant.”

Massachusetts Gov. Charlie Baker’s first response was a vote of confidence in the plant, but the next day he released a letter to John Dent, Entergy site vice president at Pilgrim, expressing “concern over the operational issues revealed during a recent inspection by the NRC” that led to the plant’s performance status demotion.

Finally, and perhaps most damaging to Entergy, is the statement of NRC Region 1 Administrator Dan Dorman.

Page 3 of 3 - The white finding, Dorman said, “highlights the continuing weaknesses in the implementation of Entergy’s program for identifying, evaluating and resolving problems at Pilgrim. Our increased oversight will focus on understanding the reasons for those weaknesses and the actions needed to achieve sustained improvements.”

There is still one last appeal of the white finding that Entergy could make but the company has not decided if it will pursue that appeal.

“Over the coming days Entergy will review the details of the NRC’s decision to consider what actions we need to take to enable Pilgrim Station to return to normal NRC oversight,” Bill Mohl, president of Entergy Wholesale Commodities, commented after receiving the NRC’s finding.

“While we are confident that Pilgrim continues to be a safely operated plant with highly professional and well-trained employees,” Mohl concluded. “We will review all the information and feedback provided by the NRC in order to continue to enhance our performance at the station.”

Follow Frank Mand on Twitter @frankmandOCM.

http://plymouth.wickedlocal.com/article/20150914/NEWS/150919529/?Start=2