The North American Electric Reliability Corporation apparently doesn't agree with that assessment: "NERC recognizes that other studies have indicated a severe

The North American Electric Reliability Corporation apparently doesn't agree with that assessment: "NERC recognizes that other studies have indicated a severe GMD event would result in the failure of a large number of EHV transformers. The work of the GMD Task Force documented in this report does not support this result for reasons detailed in Chapter 5 (Power Transformers), and Chapter 8 (Power System Analysis). Instead, voltage instability is the far more likely result of a severe GMD storm, although older transformers of a certain design and transformers near the end of operation life could experience damage." https://web.archive.org/web/20150908075507/https://www.frcc.com/Public%20Awareness/Lists/Announcements/Attachments/105/GMD%20Interim%20Report.pdf https://web.archive.org/web/20150908075507/https://www.frcc....