November 22, 2024
EMP Task Force Looks at Black Start, Nukes
NERC’s EMP Task Force held a workshop on black start, the vulnerability of nuclear plants, and skeptics who have criticized EMP research efforts.

By Rich Heidorn Jr.

NERC’s Electromagnetic Pulse Task Force held a daylong workshop July 25 with discussions on black start, the vulnerability of nuclear plants and a call for weaponizing space.

The task force was formed in April, shortly after President Trump’s EMP executive order and shortly before the Electric Power Research Institute released its report on the impact of a high-altitude electromagnetic pulse (HEMP).

NERC’s Soo Jin Kim said the workshop was part of the first phase of a three-phase plan. (See EMP Task Force Takes ‘First Bite of the Elephant.)

“We’re not jumping to a standard right away. However, I’m not promising there will never be a standard out of this effort,” she said. “What I am saying is we are going to take the methodical steps of first getting some industry input and making some strategic recommendations.”

The task force’s Phase 1 deliverable to the Board of Trustees will be “strategic recommendations we believe should be next steps for industry,” she said.

Phase 2 could result in a “handoff” to NERC’s technical committees for additional work. “That may be [standard authorization requests]; it may be guidelines; [it] may be best practices,” she said.

Phase 3, projected to begin in December, would be the creation of a standard drafting team “if we get to that point and find it’s applicable,” she said.

EMP Task Force
Phase 1 milestones for NERC’s EMP Task Force | NERC

The task force has been broken into three subgroups, one focusing on system planning and modeling (assessing the potential impacts of EMPs on the grid) and a second on critical facility assessment (how to prioritize mitigation efforts on generators, substations and control centers). The results of the two groups’ work will be used by a third group focused on mitigation, response and recovery (providing guidance to bulk power system owners and NERC committees on mitigation plans and recovery strategies).

Task force Chair Aaron Shaw, of American Electric Power (AEP), said one of the task force’s deliverables will be a bibliography of research. The Department of Homeland Security told the workshop it is conducting peer reviews of EMP studies as part of its response to the executive order.

Disrupting Black Start

The EPRI study concluded a high-altitude nuclear explosion could cause a multi-state electric outage but not the nationwide, months-long blackout some observers have warned of. (See EPRI Report Downplays Worst-Case EMP Scenario.)

One of the speakers at the workshop, an Air Force strategist, said the true threat may come from space-based lasers or microwaves rather than a nuclear detonation. (See related story, Air Force: US Must Take ‘Higher Ground’ in Space.)

Randy Horton, one of the authors of the EPRI study, said the results indicated an EMP attack could disrupt black start plans.

“We did see voltage collapse. We did identify that you could have potential relay damage,” said Horton, senior program manager for EPRI. “So, you could find yourself in the situation where you’re in a blackout and you’ve got damage to digital protective relays, potentially your [communications], your SCADA system and so on. So, you pull the black start plan off the shelf and it no longer works.”

EMP Task Force
Waveform for a high-altitude EMP | Sandia National Laboratories

Micah Till of Dominion Energy also cited the challenges of a black start following an EMP.

“If a hurricane comes through, we know what to expect from that. If an EMP happens … there’s things that we know and there’s things that we don’t know,” Till said. “Some of what we don’t know we know that we don’t know. And some of it we don’t know that we don’t know,” he said. “Questions like: How will our relays respond? What’s the coupling [the transfer of electrical energy] going to look like and is that going to get into the substation?”

He quoted former PJM CEO Terry Boston as saying, “’If you protect your black start path, then you’ve really protected against the entire threat.’

“Because who’s going to attack you if they know you can get right back up again?” Till continued. “It’s important to keep everyone from going dark, but if you can [restore power quickly], especially if the military bases and such are the ones that come up first, then there’s no real point in having the attack against us in the first place.”

Impact on Load

EPRI’s report called for mitigation to protect the grid from the impacts of E-1 pulses — the first “hazard field” caused by an EMP, which lasts for about 2.5 nanoseconds. The second impact, an E2 EMP, lasts up to ten milliseconds. The last hazard field, an E3 EMP, is marked by a very low frequency pulse that can last for hundreds of seconds. The event would be like a severe geomagnetic disturbance (GMD) caused by solar flares — albeit much shorter.

NERC Director of Engineering and Standards Howard Gugel asked Horton whether the research indicated a regional voltage collapse resulting from an E-3 pulse would have an impact on load.

“We don’t know what the impact on load [would be],” Horton responded. “We’re assuming all the load is connected when the E-3 comes through. [But] if you trip off a bunch of load due to the E-1 impacts, you’re also going to have potential voltage [problems] because you’d have a bigtime mismatch between generation and load that you’d have to worry about.”

EPRI’s report did not look at the impact on generation, but the organization pledged to do so. Horton said EPRI also plans research on distributions systems and end users, including roof-top solar.

Skeptics

Tom Popik, president of the Foundation for Resilient Societies, praised EPRI for the detail of its modeling and for testing the impact of EMPs on relays. But he said he had “concerns about the scenarios” EPRI used and pressed — unsuccessfully — for details on the latitude and longitude of the locations analyzed in the research.

Horton said EPRI did not identify the latitude and longitude of the simulated target locations because of security concerns. “We don’t want to provide a road map for the bad guys,” he said, adding that the scenarios “came straight from Los Alamos” National Laboratory.

Resilient Societies Chair William Kaewert cited Russian research he said found that an E-1 pulse would destroy medium voltage insulators in the transmission and distribution system.

“So, in contrast to the U.S. practice of testing insulator voltage breakdown deenergized, the Russians actually tested with the lines energized. And what they found was the E-1 event would actually start the arc that the line voltage would maintain until the insulator melted,” he said. ” … What we would encourage is a small number of key assets in the power system are protected to a high level such that we can reduce our recovery time should one of these events ever occur.”

Impact on Nuclear Generators

Exelon Generation’s Scott Greenlee discussed the potential impact of an EMP on nuclear generation, rejecting claims it could result in an accident and core meltdown.

“We do not believe that is the case. As a matter of fact, we think the nuclear plants can absolutely maintain safe shutdown following an electromagnetic pulse,” said Greenlee, senior vice president for engineering and technical support at Exelon Generation’s nuclear division.

He noted nuclear plants’ safety systems are typically encased in buildings with at least two feet of concrete and rebar around them, which he said would act as a “Faradaytype cage” to protect them.

“Even in the case where we have penetrations through the building — even if some of the pulse is able to transmit into the building — our safety systems are typically extremely rugged,” Greenlee said. “They’re old analog equipment for the control systems: old analog relays and rugged pumps and motors and diesel generators. … All of our key safety systems can be operated manually.”

He acknowledged, however, digital controls on non-safety systems such as turbines, generators and feedwater systems may lack concrete shielding and could be vulnerable. “It could take weeks, if not months, to restore those systems,” he said.

EMP Task Force
Conductive concrete, shielded cables and metallic enclosures are three EMP mitigation solutions for substations. | CenterPoint Energy

Another concern for nuclear operators is restocking their diesel fuel after their on-site supplies — a seven-day minimum is required — run out. “We think if there were an EMP, we really need the federal government to ensure we can resupply the nuclear units,” Greenlee said.

He said nuclear plants would not be able to take a lead role in black start operations. “Most of our plants, especially the pressurized water reactors, require 20 or more MW to start up in order to get all the equipment running. So, we would need some source of power to restore the nuclear units.”

Don’t Ignore the Physics

Scott Backhaus, EMP coordinator for the Department of Homeland Security, described his role in managing DHS’s work on EMPs and GMDs and its interactions with other federal agencies and industry. DHS is working under the direction of the president’s executive order, DHS’s EMP strategy and the National Space Weather Strategy.

The executive order calls for “sustainable, efficient and cost-effective” responses to improve resilience to the impact of EMPs. To that end, Backhaus said, the government is committed to using the “best available science” in its analyses.

“Impacts may already be mitigated by existing control systems, redundancy, backup, hardening and restoration plans,” he said.

“There are physics and engineering constraints that can be used in both the analysis of EMP waveforms and EMP impacts to avoid overestimation of risk,” he added. “If you ignore some of the physics and you ignore the engineering, you can quickly get into worst case on top of worst case on top of worst case and you [can] overestimate risk.”

He said other infrastructure sectors have done less sophisticated analysis than the grid.

“The electric subsector is likely the most sophisticated and mature in this respect, but we do have to meet each infrastructure sector where it is currently because of the timelines we’re under,” he said. “So, we have to leverage existing modeling and simulation and test data.”

Enough Generation?

Resilient Societies’ Popik questioned whether the grid has enough fuel secure, resilient and dispatchable generation to restart the grid. “This issue is not just an EMP issue, it’s a cybersecurity issue,” he said, citing the interdependencies between renewable generation and natural gas facilities that ramp to respond to renewables’ variability.

“I think the industry is trying to play the hand it’s been dealt in terms of assets, but maybe we as a society need to ask for more fuel secure assets,” Popik said. “Does anybody share this perspective? Are we kind of the voice in the wilderness on this?”

“I won’t answer that question,” responded NERC’s Gugel. “But one promising thing I’m seeing is the work DOE is doing right now in creating the North American Energy Resiliency Model, which looks at all the interdependencies — the communications and gas … so we can finally have a cohesive model of all of those different infrastructures so we can look at the interdependencies of one on the other.” The model is expected to be released in September. (See “North American Energy Resiliency Model” in National Labs Show Their Wares on Capitol Hill.)

Gugel also cited NERC’s annual long-term reliability assessments and the study it released in December on the potential impact of accelerated coal and nuclear generation retirements. The study, which some criticized as unrealistic, found faster-than-expected coal and nuclear plant retirements could jeopardize reliability if grid operators are not prepared. (See NERC Releases ‘Stress Test’ Analysis of Gen Retirements.)

NERC & Committees

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