The Amazing Collapse with the Palisades Nucelar Plant.

The research concluded that the cause of the failures is fatigue-related effects from the operation of the pumps in conditions beyond the maximum flow rates and below the minimum net positive suction head recommendations as described in the UFSAR and other design documentation.

Palisades yellow finding not red.

I’ll just say, San Onofre came to the end through many years of horrendous maintenance and operational problems. The last straw came from poor maintenance and bum engineering associated with the new generators. I think if San Onofre had a sterling NRC and public record...they would have survived.

Do you even want one nuclear plant operating in the USA if the agency allows a corporation to operate a nuclear plant in such a sloppy manner...indeed the NRC's ROP accommodates this sloppiness over and over again?

SUBJECT: PALISADES NUCLEAR PLANT INTEGRATED INSPECTION REPORT 05000255/2012003

The inspectors identified a finding of very low safety significance and associated NCV of 10 CFR 50 Appendix B, Criterion III, Design Control, for the failure to operate the Primary Coolant Pumps (PCPs) in accordance with their design operating criteria. In October 2011, a slight rise in vibration levels on the ‘C’ PCP occurred and was sustained for approximately 24 hours. This was followed by a short spike in vibrations and a return to a lower stabilized value than what had been previously observed. Investigation by the licensee revealed it was likely a piece of an impeller vane which had deformed and broken free. Based on a review of operating experience associated with impellers and further licensee investigation, the inspectors concluded that the PCPs had been operated outside of their license/design basis as stated in the Updated Final Safety Analysis Report (UFSAR) with regard to minimum net positive suction head and maximum flow. Further, based on impeller-like pieces found in the reactor vessel in 2007 (which an apparent cause stated likely came from a PCP), and an operating history which indicated past occurrences of vane breakage and degradation, the inspectors concluded the licensee had the ability to foresee and correct the condition affecting the PCPs prior to the release of a piece in October 2011. The licensee entered the issue in their Corrective Action Program (CAP) as CR-PLP-2011-5744 and performed additional research into the phenomena leading to the impeller degradation. The PCP operating sequence was changed, an Operational Decision Making Issue was implemented, and efforts to explore further procedural changes are on-going to mitigate degradation of the impellers.

Criminal facilitative assumptions never backed up by science and evidence...judgement dictated by self interest and massive political corruption. The utilities get to write the rules and control the agency.

2012-003:Investigation by the licensee with the assistance of outside consultants concluded it was likely that a piece of the ‘C’ PCP impeller deformed and broke free. There was no indication of degradation to the primary coolant system or reactor core components as a result of this postulated failure. NRC inspectors, including experts at the Offices of Research and Nuclear Reactor Regulation (NRR) reviewed the data gathered by the licensee and concluded that the pump was safe to operate until the refueling outage in April 2012 with the monitoring plan that the licensee had put in place.

This is a huge piece of metal.

The metal is 5 inches by 12 inches long..

"Lindsay Rose, spokeswoman for Entergy Corp"...why do we let these officials speak to us so plausibly stupid. Why are they so ill prepared with the history of the plant when they talk to the public? Why aren't they technical people talking to us instead if highly paid corporate spokesmen paid to talk stupid to us! This was intentional she didn't have the history on the impellers.

Rose said she did not have any information about when the metal piece might have broken off the impeller, which has been replaced. An impeller is a rotor that is used to pump water within the reactor.

Exactly like the "safety injection refueling water tank", which took them decades of leaks and half ass fixes before they discovered the tanks weren't constructed as designed (constructed poorly). Don't forget about the massive self-destruction of the CRDMs Palisades is dealing right now. The repetitive nature of flaws, cracks, leaks and shutdowns...the obscene nature of the exact same NRC violations and failed revolutionary alloy designs repeated over and over again derived from poor quality maintenance and plant operations!

The NRC accommodates plant and corporate destructive behavior...they aren't in the game of mandating a change of bad behavior! The NRC isn't in the game of picking up the easily detectable early stages of bad behavior...then turning it into good business behavior towards the better interest of the USA and our communities.

The licensee identified impeller cracking had been observed at Palisades on several occasions since 1984, when the pumps had been removed for inspection and refurbishment/replacement.  

How many pieces? Obviously they falsified past investigations and searches for broken impeller pieces...knowing the current piece was unrecoverable or not removable. At worst, they were incompetent with past searches.

Additionally, pieces suspected to be from impellers were discovered in the bottom of the reactor vessel in 1984 and 2007.  

The impeller is terrible and dangerous news...but all the things that has happened in last four years at this plant is much worst?

Epic non-conservative judgment. It is systemic engineering certainty and uncertainty gaming. Why didn't the agency stop Palisades...make them inspect all the PCP impellers considering all this history.  The 2011 Red Finding yellow finding spoke of endemic and habituated non conservative judgement (a pattern). They are doing the same engineering and regulatory gaming with the massive and repeated CRDM cracks  and the broken off impeller....the yellow finding medicine through 2012 absolutely did not take hold. It was all a phony fake phony facade.

I'll put it in the grid and ISO perspective. Exelon is threatening to shutdown a assortment of nuclear plants within a short period because of low ISO market price and unfair competition from green electricity. The NRC is severely pulling their punches because they know Palisades is so economically vulnerable. Why didn't we ever know what the true motives of  decision  the NRC and Entergy makes? Why is everything always hidden from us.Why is our electricity market so Soviet when we are supposed to be be the most open society is the world?

Approx May 2012: In response to the discovery of two pieces that resembled the PCP impeller composition during reactor vessel inspections in 2007, the licensee conducted an apparent cause analysis. The conclusion was that the pieces were most likely from the ‘D’ PCP. Additionally, the analysis explored the history of Palisades’ PCP impeller conditions which included repeat occurrences of cracking having been identified and an instance of "heavy recirculation damage," which rendered an impeller unfit for continued use. The pump manufacturer, Flowserve, also released a Tech Alert due to the Palisades PCP vane cracking history. The apparent cause analysis implied that the pieces were fatigue generated and that additional vane breakage was possible. Despite this, the PCPs were not declared as non-conforming nor were any compensatory measures taken. When the ‘D’ PCP was later inspected after removal during the 2009 refueling outage, it did not have any pieces of impeller missing. Inspections of the other PCPs, which were recommended in the apparent cause and had been planned to be executed if the ‘D’ PCP was not the source of the 2007 pieces, were cancelled. The cancellations were based, in part, on thoughts that the pieces may have originated elsewhere. However, vessel inspections done in 2007 revealed no deficiencies that would infer the pieces were generated somewhere within the reactor vessel, and the 2007 apparent cause analysis had essentially ruled out other sources.

Come on, the inspection was cancelled because they were trying to save a few pennies by not lengthening a outage.

Remember, I talked about beautiful science and technology. Why didn't the fixes coming out of the 2012 NRC  inspection put an end of with vane damage. They inspected the impeller this outage and then found this huge piece of metal at the bottom of the vessel.  Obviously the pump is a defective design...not good for the duty intended. We still don't know why Palisades operated this pump outside the manufacture recommendations. I try to use science to anticipate problems and fix them early...Palisades and the NRC use science and engineering to justify not fixing defects and running equipment irresponsibly. Science is just a tool..you can use any tool to do good or evil. It is just our choice!

Rose said the impeller piece was from one of the plant's four main coolant system pumps. That impeller was recently replaced during this outage, she said.

Personally in the below, I'd be worried PCP seal damage with a damage off balanced impeller...that is in the accident studies with the largest risk to the community. I wouldn't trust the accuracy of the installed vibration detectors.

Any good corporate citizens would immediately recognize weld repairing a safety related nuclear pump impeller in a high temperature environment is just plain crazy science and engineering talk. Where is the NRC in establishing standards! Maybe the pump is so obsolete they didn’t have new impeller in stock? Why has the NRC allowed  Entergy to weld repair PCP impellers?    

The licensee noted, based on metallurgical examination of a previous fragment, previous pump inspection findings, and the mechanism by which the cracks propagate, that weld-refurbished impellers were particularly susceptible to degrading to a point where a piece could be released.

Entergy always knew where to look.

Additionally, pieces suspected to be from impellers were discovered in the bottom of the reactor vessel in 1984 and 2007.

I think this all is a broad corporate business philosophy...Entergy is Systematically Destroying Nuclear Plants through a Run-to-Failure Philosophy. Here is a new Pilgrim nuclear plant NRC inspection report. The agency speaks of a non-safety component run-to failure philosophy. Gets you wondering, will the non safety equipment run-to-failure-philosophy cause the public to lost faith in the safety of a plant. It might be legal to the NRC, but will not be excepted by the public?

Pilgrim Plant-The following observations have been noted by the inspectors: SRV performance was a driver for several down powers and forced outages in 2012 and into 2013; a number of unplanned down powers and shutdowns were the result of non-safety-related equipment failures; it appears that non-safety-related equipment that was characterized as a run-to-failure is starting to reach the end of their service life and can likely become contributors to such events.

Basically the NRC and Entergy are saying it is safe to operate these components outside their manufacturer designs...even after repetitive damage. Even after the manufacture’s told them to knock it off. It is self-destruction on a massive scale! The NRc allows a utility to run to failure safety components...this is a run-to-failure philosophy just like Pilgrim except it is actually safety related.   You notice the NRC never gets to the bottom of it...public disclosure.. what was the ultimate rationale or justification with why Entergy was operating these components to damage outside the manufacturer’s recommendation.

The research concluded that the cause of the failures is fatigue-related effects from the operation of the pumps in conditions beyond the maximum flow rates and below the minimum net positive suction head recommendations as described in the UFSAR and other design documentation. These conditions are present when operating only one or two PCPs during reduced temperatures and pressures (typically during startup and shutdown activities). Cyclic pressure pulses and stresses are created under these reduced pressure conditions that act on the leading edges of the impellers, which can ultimately lead to vane cracking and the release of impeller fragments. The licensee noted, based on metallurgical examination of a previous fragment, previous pump inspection findings, 18 Enclosure and the mechanism by which the cracks propagate, that weld-refurbished impellers were particularly susceptible to degrading to a point where a piece could be released. Currently, none of the PCPs contain any remaining weld-repaired impeller areas (ones that did are postulated to have released pieces already). Also, at normal operating temperature and pressure, there is adequate net positive suction head on all PCPs, so these additional stresses are not present.

In response to the discovery of two pieces that resembled the PCP impeller composition during reactor vessel inspections in 2007, the licensee conducted an apparent cause analysis. The conclusion was that the pieces were most likely from the ‘D’ PCP. Additionally, the analysis explored the history of Palisades’ PCP impeller conditions which included repeat occurrences of cracking having been identified and an instance of “heavy recirculation damage,” which rendered an impeller unfit for continued use. The pump manufacturer, Flowserve, also released a Tech Alert due to the Palisades PCP vane cracking history. The apparent cause analysis implied that the pieces were fatigue generated and that additional vane breakage was possible. Despite this, the PCPs were not declared as non-conforming nor were any compensatory measures taken. When the ‘D’ PCP was later inspected after removal during the 2009 refueling outage, it did not have any pieces of impeller missing. Inspections of the other PCPs, which were recommended in the apparent cause and had been planned to be executed if the ‘D’ PCP was not the source of the 2007 pieces, were cancelled. The cancellations were based, in part, on thoughts that the pieces may have originated elsewhere.

Engineering certainty/uncertainty gaming...pernicious engineering language corruption. 

However, vessel inspections done in 2007 revealed no deficiencies that would infer the pieces were generated somewhere within the reactor vessel, and the 2007 apparent cause analysis had essentially ruled out other sources.

In response to the October 2011 event and subsequent research conducted to better understand the phenomena affecting the PCPs, the licensee has instituted a monitoring plan, changed the preferred sequence for starting/stopping PCPs during startups and shutdowns, and has corrective actions to explore further procedure changes regarding operation of the PCPs and the resultant impact on other aspects of plant operation.

Yet here we sit in 2014 with a broken impeller and a blade stuck in the vessel.

Since the licensee was intending to have this non-conformance on the C pump (missing impeller pieces) the entire cycle, the inspectors (including experts at the Offices of Research and NRR) reviewed the impact of this non conformance on the PCP safety functions. Key safety functions of the pump are to provide a coolant pressure boundary and ensure an adequate coast down of flow. The review indicated there were no current safety issues with this non-conformance. The inspectors are evaluating the monitoring plan to determine its long-term effectiveness.

COVERT TOWNSHIP, MI — A piece of metal from a broken impeller blade has lodged in the reactor vessel at Palisades Nuclear Power Plant. Workers discovered the issue during the nuclear power plant's scheduled refueling and maintenance shutdown, which began Jan. 19.

The metal is 5 inches by 12 inches long, said Lindsay Rose, spokeswoman for Entergy Corp., which owns Palisades. The piece is wedged into the reactor vessel between the vessel wall and the flow skirt, inside the vessel.

They know where to look (2011)..."aadditionally, pieces suspected to be from impellers were discovered in the bottom of the reactor vessel in 1984 and 2007".

"It's physically separated from the fuel," Rose said in an interview with the Kalamazoo Gazette. "It's not a loose piece floating around. It's firmly wedged into place."

Efforts to remove the metal have proved unsuccessful. At this point, Entergy plans to leave it in place, saying it does not pose a safety risk.

"We took steps to remove it. We've thoroughly analyzed it and we've determined that, based on the location of where it is, it's not going to have any impact on safe operations. We do not believe it is going to move from its location," Rose said. "It has not compromised safe operations and it is not expected to."

Rose said she did not have any information about when the metal piece might have broken off the impeller, which has been replaced. An impeller is a rotor that is used to pump water within the reactor.

The Nuclear Regulatory Commission is aware of the issue and its on-site inspectors are monitoring the situation, NRC spokeswoman Viktoria Mitlyng said.

"We are aware that there is a small piece of metal that is stuck in the reactor. The company has tried different methods for removing it and it is wedged really tightly," said Viktoria Mitlyng, senior public affairs officer for the NRC, in a phone interview. "With some of the more intrusive methods that could be used, there's a danger of actually damaging the vessel. We don't know what the resolution is going to be, but we're following this issue."

Entergy Corp. bought Palisades from Consumers Energy in 2007 for $380 million. The one-reactor plant, which is located along Lake Michigan in Covert Township, supplies about 20 percent of Consumers Energy's power. The facility came online in 1971 and its license runs until 2031.

The plant has shut down at least 10 times since 2011 for repairs, including a month-long shutdown in 2013 to replace the bottom of its safety injection refueling water tank. That shutdown came after approximately 80 gallons of highly diluted radioactive water leaked out and made its way into Lake Michigan in May.

The NRC will have the final say on whether the metal represents a safety-significant issue, Mitlyng said.

"If they propose to leave the metal in the reactor core, they have to provide analysis and justify to the NRC that leaving that in there would not have an impact on the safe operation of the reactor," she said.

Mitlyng said plants have been able to operate with "similar matter" in the reactor.

"However, licensees are required to evaluate the nature of the material and determine whether there will be an adverse impact on safety," she said.

The NRC and its experts will then review the evaluation to determine whether the plant can continue to operate safely.

While he did not have firsthand information about the specific situation at Palisades and could not comment on it, there have been at least three other instances in the U.S. of reactors that operated with metal debris inside, said David Lochbaum, director of the nuclear safety project at the Union of Concerned Scientists.

Lochbaum said he experienced one of those instances first-hand.

When he was stationed at the Browns Ferry nuclear plant in Alabama in January 1980, workers kept track of fuel bundles by moving metal squares on vertical wooden boards.

While one of the three reactors at the plant was shut down for refueling, "the tag board was knocked over twice, dumping dozens of metal tags into the spent fuel pool and onto fuel bundles to be reloaded into the reactor core," he said in an email. "The metal tags were just large enough to block off flow through a bundle. We looked for but did not find all missing tags, and had to analyze the 'what if' scenario if a tag got carried into the reactor vessel. Because it would only have caused overheating damage to one fuel bundle, an outcome within the design of the plant to withstand, we were allowed to restart. The missing tags were never found, but they never caused problems wherever they went."

Quad Cities Generating Station in Illinois also encountered loose metal parts with minimal problems, Lochbaum said.

However, in 1992, the Connecticut Yankee nuclear plant experienced more serious damage when workers removed the thermal shield, a metal plate that was designed to act as insulation but was found to be unnecessary. When cutting through the plate, the workers created metal slivers and flakes that were not fully removed before the reactor started, Lochbaum said.

"It damaged the metal fuel rods either by direct impact or by lodging against some of the framework holding the fuel rods. Water flowing past vibrated the debris against the fuel rods, wearing it away. Workers had to shut down the reactor and inspected each and every fuel rod for signs of damage — replacing the damaged fuel," he said.

Until the NRC is satisfied with Entergy's evaluation of the situation, Mitlyng said, Palisades will not be allowed to restart.

"Our inspectors are evaluating the activities as they unfold," Mitlyng said. "What I can tell you is that we will have to be comfortable with the analysis and their proposed solutions before the reactor can return to power."

Yvonne Zipp is a staff writer at the Kalamazoo Gazette. Email her at yzipp@mlive.com or follow her on Twitter.