EPRI report says existing tech would protect U.S. grid against electromagnetic pulses
Three years of electromagnetic pulse simulations and testing by the Electric Power Research Institute (EPRI) show that America’s electrical grid could withstand the impact of an EMP triggered by a nuclear weapon, according to research findings released on Tuesday by the independent, nonprofit group.
“A properly functioning electric grid is critical to national security and society and its potential loss for an extended period (months or longer) could severely impact both,” writes Randy Horton, senior program manager, in the EPRI report, High-Altitude Electromagnetic Pulse and the Bulk Power System: Potential Impacts and Mitigation Strategies.
However, according to Horton, the subsequent research findings — based on an evaluation of the potential effects on just the U.S. electric transmission system — indicate that if a high-altitude electromagnetic pulse (HEMP) attack occurred similar to those tested, then impacts such as regional disruption or damage to digital protective relays (DPRs) and regional voltage collapse could be experienced.
But potential impacts of HEMP would vary depending on the component that’s responsible for the resulting disruption or damage, Horton writes in the report.
Such components, he said, can be caused by a nuclear explosion above Earth’s atmosphere that propels electromagnetic energy toward the surface, generating an initial, short-duration E1 EMP; an intermediate E2 EMP similar to those caused by nearby lightning strikes; followed by a late E3 EMP that’s similar to a severe geomagnetic disturbance caused by solar flares, according to EPRI.
The main goal of the EPRI research effort, launched in April 2016, was to provide the electric utility industry and other stakeholders with an unclassified, technical basis for assessing the potential impacts of a HEMP attack on the transmission system, and hardening the system against any impacts found to be of significant concern.
The research is specifically focused on the electric transmission system, such as overhead transmission lines, substations, and switchyards. Researchers did not consider the potential effects of HEMP on generation facilities, nuclear reactors, distribution systems, loads, or other key elements or infrastructure sectors, according to the EPRI report.
Key findings for the E1 EMP show that transmission electronic equipment damage or disruption can result from induced voltage surges in connecting cables, as well as by direct exposure to the initial pulse, according to the report.
And DPRs — which are devices that help detect faults in the electric system — generally were found to be resilient to direct exposure to the E1 EMP, but also vulnerable to the surges induced on control and communication cables, the report says.
However, EPRI researchers found that such initial pulse impacts could be mitigated through a variety of existing options, including shielded cables having proper grounding; low-voltage surge protection devices and/or filters; and grounding and bonding enhancements, among others.
The research also showed that the combined effects of the E1 and E3 pulses could trigger a regional service interruption but would not trigger a nationwide grid failure, and recovery times would be similar to those resulting from large-scale power interruptions caused by other events provided that mitigations specific to the E1 pulse are deployed, according to the report.
Regarding the E2 intermediate pulse, the system impacts were minimal so EPRI researchers made no further mitigation option recommendations.
“The technical basis for these findings and options for mitigating the potential impacts that were identified have been made available in this report so that the electric utility industry and other stakeholders can have the data necessary to make more informed decisions regarding the threat of a HEMP attack on the U.S. electric grid,” Horton wrote.
Michael Howard, president and chief executive officer of EPRI, said the group’s research represents the largest utility collaborative around the issue to date and was funded by more than 60 U.S. utilities.
The Defense Threat Reduction Agency, the U.S. Department of Energy, three federal nuclear weapons laboratories, and the Electricity Subsector Coordinating Council (ESCC) also collaborated on the EPRI project, which focused on understanding the technical facts using both laboratory testing and advanced modeling.
“The results also provide a cost-effective pathway to enhance the resilience of the grid and accelerate recovery,” Howard said.
Scott Aaronson, vice president for security and preparedness at Edison Electric Institute (EEI), which represents the nation’s investor-owned electric companies, agreed Tuesday that protecting the nation’s energy grid and ensuring a reliable and affordable supply of energy remain top priorities for America’s electric companies.
“How an EMP may impact critical infrastructure is an extremely complex issue that cannot be addressed with a one-size-fits-all solution,” Aaronson said. “This research enables electric companies to make science-informed decisions for developing, testing and deploying EMP-resistant grid components.”
Aaronson added that the EPRI study provides electric companies with a better understanding about what the impacts could be if a nuclear weapon detonated above the continental United States and also allows them to better prioritize risk around their critical assets.
“EPRI also tested mitigation strategies and was able to rule out options that don’t work and to identify strategies that mitigate the impacts from an EMP,” said Aaronson. “Multiple electric companies will be piloting those potential solutions to ensure that new mitigation strategies do not impact other energy grid equipment or undermine or conflict with mitigation and protective measures that already are in place.”
In fact, EPRI is working with utilities to continue evaluating mitigation options for the E1 EMP, including additional tests to more fully understand performance and reliability. EPRI also plans to expand the application of its research results to power generation.
“EPRI’s research continues to support the very high priority that the electric utility industry places on providing reliable electricity for all customers,” Howard said.
Thomas Fanning, chairman, president and CEO of Southern Company and co-chairman of the ESCC, called the EPRI research “groundbreaking” during an EPRI-hosted industry event on Monday held at the Charlotte, N.C., EMP testing facility where much of the EPRI analysis and tests were conducted.
“In the interest of national security, protecting the grid and preserving our American way of life, the ESCC and the electric power industry will use these findings to continue our work with the federal government to develop the optimal strategies to prepare for, and respond to, security threats,” he said.
