Small cracks have been found a half-dozen times in the past 20 years in pipes that carry fuel to emergency generators that provide cooling water for a reactor if electricity fails at the V.C. Summer plant near Columbia, according to the U.S. Nuclear Regulatory Commission.

The agency issued what it calls a preliminary “yellow” warning to plant owner Dominion Energy last week.

It is the second most serious category and only seven similar warnings have been issued across the country since 2009, nuclear power expert David Lochbaum told The State newspaper after reviewing records from federal regulators.

A crack first appeared on a diesel fuel pipe in 2003, and similar pipes have had other cracks since then.
During a 24-hour test of the system in November, a small diesel fuel leak grew larger, according to NRC records.

The agency issued the preliminary yellow warning because of the repeated problems.

The commission’s ruling is not final and Dominion will have a chance to explain what happened, utility spokesperson Darryl Huger wrote in an email

Dominion has already started to put in place a plan to improve the reliability of the backup system and like all nuclear reactors there are multiple backup systems in case any component fails, Huger said.

“With a commitment to continued safe operations, we are inspecting and maintaining our generator and related components. We will continue to keep the NRC updated on our future strategy to further enhance our diesel generators,” Huger wrote.

Virginia-based Dominion hasn’t been the only owner of the plant. SCANA built and started the plant in 1984. The South Carolina company had plans to build two more reactors, but billions of dollars of cost overruns forced it to abandon the project in 2017 and sell to Dominion.

Dominion has recently requested to renew the license for the nuclear plant for an additional 40 years.
Longtime nuclear safety advocate Tom Clements told the newspaper the pipe problems should mean a lot more scrutiny by regulators.

“This incident serves as a wake-up call to fully analyze all such systems prior to a license-renewal determination,” Clements said in an email.

The ACRS provides expert advice on matters related to the safety of existing and proposed nuclear facilities and on the adequacy of proposed reactor safety standards. It also advises the Commission on issues involving radiation protection and radioactive waste management.

In a statement, the NRC said that candidates are expected to have extensive experience in nuclear reactor safety issues, particularly engineering and safety issues associated with new light-water and non-light-water reactor designs and technologies, or in similar fields of nuclear reactor and nuclear fuel cycle safety.

It said the best-qualified candidates will have at least 20 years of experience and education and a record of achievement in one or more areas of nuclear science and technology or related engineering disciplines.

Resumes are being accepted until October 5, and may be sent to Sandra Walker, ACRS, Mail Stop T2B50, U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, or e-mail Sandra.Walker@nrc.gov. More information on the advisory committee can be found on the NRC website.

Inspectors with the U.S. Nuclear Regulatory Commission (NRC) failed to properly inspect Diablo Canyon Power Plant pipes before a cooling system leak shut down one of the plant’s two reactors for eight days in 2020.

The findings were released by the U.S. Office of Inspector General (OIG) on March 28.

In the last few years inspectors said they had reviewed multiple concerns about the NRC’s oversight of Diablo Canyon’s safety-related structures, systems, and components. Concerns included specific allegations that the NRC had inadequately inspected the plant’s auxiliary feedwater system (AFS) prior to the cooling system leak.

An AFS is a backup water supply that can be used to cool the reactor if normal feedwater is out of service.

According to the OIG’s findings, the NRC failed to identify AFW piping insulation in Diablo Canyon’s Unit 2 that had long been in a degraded condition. This degradation led to the leak which Pacific Gas & Electric (PG&E) employees found while working at the plant on July 23, 2020. PG&E owns and operates Diablo Canyon, the last operating nuclear plant in California.

The OIG found that at no time during the NRC’s January and April 2020 AFW system inspections, or during weekly plant status inspections, did the NRC report any findings regarding SSCs that exhibited defects--such as degraded insulation on the AFW system--that would impact function.

MORE: NRC to Address Inoperable Safety System at Diablo Canyon Nuclear Plant

The OIG findings also said the NRC had not inspected the area where the leak occurred, even though its inspection report indicated that inspectors had conducted a complete walkdown of the AFW system in April 2020.

The OIG report also said the five hours NRC staff spent directly inspecting AFW systems in both Diablo Canyon reactors was fewer than the 12 recommended in the applicable NRC inspection procedure for the complete April 2020 walkdown.

“Senior regional officials acknowledged that the inspection was inadequate,” federal inspectors said in their report.

Eight days after the Unit 2 shutdown, PG&E restarted the unit after inspecting 40 pipe sections and repairing piping in several locations to ensure pipe thickness met requirements. The NRC issued PG&E a notice of violation for “failure to appropriately screen relevant operating experience.” The commission the violation was based in part on the fact that the utility received information in 2009 and 2010 relating to corrosion of carbon steel piping under insulation, but did not identify the AFW as being susceptible to corrosion under insulation.

OIG Inspectors said PG&E remedied the AFW system failure and that the plant continues to operate safely.

The inspectors also said the NRC should ensure that its inspectors are trained to identify corrosion under insulation, that inspection procedures are adequate for walkdowns (especially with a single unit versus a multiple-unit plant), that NRC managers are involved in reviewing whether inspectors follow procedures, and that managers are appropriately involved in helping select systems and components for inspection.

The plant has two Westinghouse-designed 4-loop pressurized-water nuclear reactors. Unit 1 entered service in May 1985 and Unit 2 in March 1986.

As part of its congressionally mandated mission, the NRC regularly inspects commercial nuclear power plants. NRC inspections assess whether licensees are properly conducting operations and maintaining equipment to ensure safe operations.

In a statement sent to Clarion Energy, the NRC said it continues to have “full confidence” in its staff.

“We are reviewing the Inspector General’s report and will take appropriate action if needed," said Victor Dricks, NRC senior public affairs officer. “At no time was public safety endangered because of this incident.”

A spokesperson with PG&E said that “safety is and always will be our most important responsibility at PG&E and Diablo Canyon, and the plant has an excellent safe operating record.”

In 2018, the California Public Utilities Commission approved a settlement to shut down Diablo Canyon. The plant currently provides 8% of California's electricity production and 15% of its carbon-free electricity.

PG&E intends to begin active decommissioning of the plant in 2025 and to complete the project in one decade.

Texas Gov. Greg Abbott joined a state petition urging the U.S. 5^th Circuit Court of Appeals to vacate a federal license that would bring spent nuclear fuel to a private storage facility in the Permian Basin.

Last September, the Nuclear Regulatory Commission (NRC) issued an operating license to Interim Storage Partners LLC. The company proposed building a nuclear storage site in Andrews County, Texas, less than a mile from the New Mexico border. The facility would initially transport, receive and store up to 5,000 metric tons of spent fuel, along with another 231 metric tons of lower level radioactive waste for 40 years. Interim Storage Partners indicated the storage site could eventually handle as much as 40,000 metric tons of spent fuel.

Project costs could be about $350 million during the construction phase and total expenses of close to $2.3 billion by the end of the 40-year lifespan, according to an NRC project report.

Texas argued the NRC’s licensing exceeds its statutory authority, botches basic administrative-law principles, and fails to account for the environmental risks posed by a terrorist attack. After the operating license was granted, Abbott signed a new law, known as House Bill 7, banning nuclear storage facilities in the state.

"I will not let Texas become America’s dumping ground for deadly radioactive waste," said Abbott.

In Texas, there are two commercial reactors at Comanche Peak and two at The South Texas Project. Both sites store all of their spent nuclear fuel in spent fuel pools and in dry cask storage at their site.

Interim Storage Partners is a joint venture of Waste Control Specialists (WCS) LLC and Orano USA. It intends to construct the storage facility on property adjacent to the WCS low-level radioactive waste disposal site already operating under a Texas license.

The spent fuel and waste must be stored in canisters and cask systems, which must meet NRC standards for protection against leakage, radiation dose rates, and criticality, under normal and accident conditions. The canisters are required to be sealed when they arrive at the facility and remain sealed during onsite handling and storage activities.

Read more on decommissioning and nuclear waste management here

NRC staff concluded that land, air and water impacts from the facility would be relatively small, including about 330 acres for the storage facilities themselves. Transportation infrastructure and activities also would not be a major issue, according to an NRC report.

The report also noted environmental exposure risk was low, given the transportation safeguards and relatively short time in transport.

U.S. Department of Energy statistics indicate that the country’s commercial nuclear power industry generates about 2,000 metric tons of used uranium fuel per year. Once spent and removed from the reactor, used fuel roads are currently stored at close to 75 sites in 34 states, according to the DOE.