Pilgrim’s Problems: Juno, Scrams, and Useless Back-up Plans

In a misleading press release issued yesterday, Entergy officials (Entergy is the owner of the Pilgrim Nuclear Power Station) stated that Pilgrim “stopped operating in accordance with procedure after distribution lines that send power from the plant to the electric grid became inoperable because of the weather.” It shut down at 4:00 am on Tuesday, January 27th. In other words, Entergy claims the facility shut down only because they couldn’t send power out of the plant to the electric grid. They then went on to say that Pilgrim “was being powered by emergency diesel generators and could tap into an offsite power source (23KV power supply) if needed.”

Entergy hasn’t exactly been forthright with the level of risk associated with the Pilgrim site and flooding and storms. Not only is the information being publicized misleading, but the information reported to the Nuclear Regulatory Commission (NRC) also appears to be misleading and inaccurate. The NRC needs to require Entergy to produce an accurate flooding risk assessment, and provide accurate information relative to storms. Check out the map at the bottom of this post that clearly shows there is more risk on the site than Entergy is reporting.

Why would Pilgrim have to shut down during winter storm Juno only because power couldn’t be sent out, and why would they have to be reliant on back-up generators to operate, especially if offsite power was available?

One news outlet even went so far as to say “The power lines into Pilgrim are working, but the loss of transmission lines prevents the plant from delivering the electricity it generates.” But this was not the case at all.

Citizens made some calls to the NRC and MEMA (Mass. Emergency Management Agency) yesterday to clarify what was happening at the Pilgrim. An NRC spokesperson, Neil Sheehan, explained that the offsite power source that Entergy referred to in its press release, the 23KV line, is not set up to provide power load for the safety systems. While the only purpose of the 23KV line is to provide power for safety systems, it clearly was not available to do so – otherwise Pilgrim would not have been operating on backup generators. So Pilgrim could not tap into this offsite power source if needed. Furthermore, Pilgrim did lose its ability to access offsite power and had no option but to switch to its back-up generators.

While Pilgrim did in fact experience problems with sending outgoing power to the grid, it was not the only reason it had to switch to back-up generators. Apparently the transmission lines that deliver power from Pilgrim to the grid froze during the storm.

Finally, the Cape Cod Times published two stories late yesterday (“Frozen power lines shut down Pilgrim” and “Storm shutters Pilgrim nuclear plant”) about the shutdown that delved deeper into the issue.

Something called “arcing” occurred in Pilgrim’s switchyard (an electrical substation), which was the likely cause of the offsite power loss. The question then becomes why did the arcing occur? The NRC stated in the Cape Cod Times article that “the exact cause of the loss of 345-KV power lines is still being investigated.”

Arcing occurs when electricity jumps from a transmission line to nearby metal. In the Cape Cod Times story, David Lochbaum (Director of Nuclear Safety for the Union of Concerned Scientists) was quoted as saying, “Storm conditions, particularly at a plant adjacent to wind-driven salt water, can cause arcing.”

So the arcing was storm-caused – possibly due to wind driven waves and flooding. High tide occurred at 4:33 am, a half-hour after Pilgrim shut down. Could Pilgrim have exceeded its “Design Basis” for flooding if the storm-force waves and flood water impacted the site during high tide? Maybe seawater flooded the switchyard, also causing arcing? A Design Basis Event is an accident, natural phenomena, etc. (such as flooding) that a facility must be designed to withstand and still operate properly and safely. When a facility exceeds its “Design Basis,” it means an event occurs that a facility cannot withstand.

Two event notification reports were issued by Pilgrim on January 27th at the height of Juno. The first event report was the reactor shutdown around 4:00 am due to loss of offsite power. The second event report was issued around 9:45 am when the High Pressure Coolant Injection (HPCI) system was declared inoperable. There was apparently a malfunction and the reactor pressure control had to be transitioned to safety relief valves. The cause of the HPCI malfunction is so far unknown and Pilgrim continues to troubleshoot the problem.

All of the problems experienced by Pilgrim yesterday coincide with NRC’s recent decision to continue to rank Pilgrim as one of the worst operating plants in the country.

In 2014 Pilgrim was identified by the NRC as one of the worst performing nuclear plants in the nation, based on a variety of problems and unplanned shutdowns in 2013 (it is also called being in a “degraded cornerstone”). Earlier this week, the NRC issued a new report stating that Pilgrim has “not provided the assurance level to fully meet all of the inspection objectives and have correspondingly determined that Pilgrim will remain in the Degraded Cornerstone of the Action Matrix by the assignment of two parallel White PI inspection findings.” In other words, after a year of additional scrutiny by many NRC inspectors, Entergy still has not fixed the problems and will remain as one of the worst performers in the nation.

In this new NRC report, Pilgrim’s switchyard and transmission system are identified as vulnerable to harsh weather, especially winter storms. Clearly Pilgrim already had problems during past storms and the NRC doesn’t think Pilgrim has adequately addressed the problems. Despite this, the NRC still did not require Pilgrim to shut down as a preventive measure as Juno was tearing its way toward Plymouth.

And then what about Entergy’s Magical FLEX plan? Remember, this is what has been referred to as the “RUBE GOLDBERG” project that Entergy proposes as a back-up cooling system if back-up generators are taken out of service. The plan would involve workers from Pilgrim (or even the Plymouth fire department) to drive along the shore, set up a portable pump and hose on the shoreline to pull water from Cape Cod Bay to manually cool the reactor and spent fuel pool. With the hurricane force winds, severe flooding, white out conditions, frigid temperatures and strong storm surges and waves – is it even a question whether this back-up FLEX plan would work if an emergency would have happened yesterday during the storm?

Another hazard not mentioned in the FLEX plan is the potential for freezing. If transmission lines froze yesterday, can Entergy assure the public that the hose required as part of the FLEX plan, as well as the outhaul pulley system, will not freeze? During Juno, there has also been a freezing spray advisory as part of small craft advisories since the storm. The advisory was still calling for 0.3-0.7 in. per hour accretion on Jan. 28th, after the worst of the storm had passed.

As of 4:30 PM on Jan 27th, Pilgrim went into “cold shutdown” until the power from offsite can be restored. There is no estimate for when it will come back online. At this point, with all the problems associated with the facility, we believe the NRC should not allow Pilgrim to restart at all.

Another issue that has yet to be addressed by Entergy is how the two, newly-filled dry casks weathered the storm this week. Entergy moved nuclear waste for the first time from Pilgrim’s wet pool into dry casks earlier in January. These casks – sitting a mere 175 feet away from the shoreline and only about 6 feet above FEMA’s flood level – are also at risk to the harsh coastal conditions during storms. In addition to flooding, approximately 30 inches of snow was reported in the Plymouth area. There are air vents at the bottom and the top of each cask, which are designed to keep the nuclear waste inside cool. There is concern that these vents could become blocked or clogged (with flood water or a snow drift, for example) and the nuclear waste could overheat. Read more: “Historic Nor’easter Underlines Risks at Pilgrim”.

If Pilgrim is allowed to come back online, it’s clear that Entergy needs to be fully accountable to the public and produce an accurate assessment of its risks to flooding, storms, wind and waves. The NRC must require Pilgrim to develop an updated and honest assessment of the potential hazards on the site, which so far it has not done. Check out the maps below that we recently developed. It goes to show that there is more risk on the site than is currently disclosed by Pilgrim.

Topographical map of the Pilgrim site. Jan 2015. (click to view a larger image)

Topographical map of the Pilgrim site. Jan 2015. (click to view a larger image)

Additional articles and information:


  1. Kai

    For all interested, http://www.enenews.com is an excellent source for news regarding nuclear energy.

  2. Curt

    All steam power plants, nuclear or not, shutdown if electricity cannot be transmitted. Electricity is not stored in large amounts. If it cannot be transmitted and used immediately, generation must cease. This is not unique to a nuclear power plant.

    • Nuclear Reason

      I agree this is misleading. Even the wind turbines across the highway have to come to a stop when NSTAR’s archaic grid goes down. Of course they just cool off and chill unlike the potential “situation” that can happen at Pilgrim where cooling *must* continue at all times.

      I am 100% for getting Pilgrim offline permanently though – if only because it has vastly, vastly, vastly out-operated it’s design lifetime. It’s old baby. It’s one thing to drive a Ford Taurus into the ground. An entirely different matter when you’re talking about an outdated 665 MW BWR reactor that’s right next to millions of people.

  3. The Paper Fantasy And Real Dangers Of New Generation Nuclear Reactors; via @AGreenRoad

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  5. TEC

    The 23 KV source was available. The 23 KV source is an emergency backup line that is provided for additional defense in depth in beyond design basis events and is not normally used. The diesel generators are always activated when offsite power from the plant’s 345 KV substation is unavailable as they are safety rated and can respond automatically while the 23 KV line is not safety related equipment and transferring of plant loads to the 23 kv source is a manual process. The 23 KV line is an Eversource distribution line from a local distribution substation and would and would not normally be connected unless needed. Vermont Yankee had a similar setup with a connection to a hydroelectric station located at a dam right next to the plant, this line serves the same purpose that did at that plant.

    At Pilgrim during operation, the plant systems are powered by the turbine generator output through a transformer (the unit auxiliary transformer) that taps off the bus duct between the turbine generator output and the step-up transformer and the rest of the generated power is then sent to the grid from the step-up transformer via the 345 kv substation and two transmission lines. This is pretty standard in power plants. When operating the plant is powering itself and power is flowing out of the plant. When the plant is offline, offsite power is received from the grid via the same two transmission lines and a separate transformer (the startup transformer) that is connected directly to the 345KV substation supplies the plant’s electrical systems. The electrical buses switch between the ST and UAT via a fast bus transfer mechanism, common in many power plants not just nuclear. When the transmission lines were tripped, the plant had no where to send its power like Curt said so it shut down as designed and the shut down then triggered a loss of normal power to plant systems (since power was available from neither the UAT or ST.) The emergency diesel generators started as designed because power was lost to the safety buses from the normal 345kv source. The 23 KV source serves as an additional power source that can act as a maintenance source or an additional backup to the diesels in a major emergency.

    Current nuclear plants do not have the ability to rapidly ramp down to low power levels in the event of a total loss of load to avoid having to shut down. Some of the new nuclear designs such as the AP1000 are designed to handle a 100% load rejection without a turbine trip, this is thanks to advancements in turbine bypass systems and fine motion control rod mechanisms that can allow the reactor to be quickly and safely brought down to low power levels (but not outright shut down.) Note that this is not a safety feature but is more designed to mitigate downtime when transients on the transmission system occur as the plant could then be quickly reconnected to the grid without the long startup process.

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