Earlier this week, the 680-megawatt Pilgrim Nuclear Power Station in Plymouth, Massachusetts had its safety rating downgraded by the Nuclear Regulatory Commission (NRC). The primary reasoning was the reoccurring problems with the plant’s safety relief valves closing during the cooling process. The plant’s safety rating was also downgraded in 2014 after a series of unplanned shutdowns in 2013. The latest downgrade was the result of a shutdown earlier this year where one of the safety valves concerned again failed to open. Though no nuclear plants in the U.S. hold the lowest rating, Pilgrim’s recent downgrade makes it one of three that share the second to lowest. The downgrade puts the plant in the “repetitive degraded cornerstone, multiple degraded cornerstones, or multiple YELLOW inputs, or one RED input” category of the NRC Response Plan, which requires the commission to increase its oversight of the plant.

David L. Ryan/Globe Staff/File

The NRC said that it was downgrading the safety rating as part of an effort to investigate what problems led to the shutdowns in 2013 and 2015. According to Neil Sheehan, a spokesman for the NRC, “Pilgrim is going to receive scrutiny at the highest levels.” However, the regulator made special mention that the site was not dangerous and that there was no threat to the public or workers at the plant. The increased attention will include more regular check-ups and a required plan of action from Entergy, the operator of the plant.

Senator Ed Markey (D-MA) commented on the downgrade, expressing frustration over “repetitive safety problems.” He also expressed worry that the plant “is the same design as the reactors that melted down during the Fukushima nuclear disaster.”

The other two sites that have the second lowest safety rating, Arkansas Nuclear One and Arkansas Nuclear Two, are also operated by Entergy.

Sources and Further Reading:

  1. Inquiry to begin over Pilgrim nuclear plant’s ‘safe’ shutdown – The Boston Globe
  2. NRC Response Plan or “Action Matrix” – Nuclear Regulatory Commission
  3. Pilgrim nuclear plant one step from shut down by regulators – Cape Cod Times
  4. Pilgrim nuclear plant safety rating downgraded – The Boston Globe
  5. A comparison of U.S. and Japanese regulatory requirements in effect at the time of the Fukushima accident – Nuclear Regulatory Commission
  6. Most Vulnerable U.S. Nuclear Plants – The Daily Beast
  7. Operation Nuclear Power Reactors – Nuclear Regulatory Commission
  8. Pilgrim Nuclear Power Station Home Page
  9. The Lifespan of U.S. Reactors – Bloomberg Business