A new order issued by the Nuclear Regulatory Commission (NRC) last week gives 31 U.S. reactors a year to further improve their venting systems as a safeguard during potential accidents. Over the past week, the NRC also called for comment on foreign public ownership issues and issued a Final Environmental Impact Statement (EIS) for the Watts Bar 2 operating license.

Enhanced Requirements for Post-Fukushima Venting Systems

The June 6 order from the NRC supersedes a March 2012 order that applies to 31 U.S. reactors with "Mark I" and "Mark II" containments and requires them to install or improve their "hardened" venting systems to safely vent pressure from containment buildings during potential accidents. The new order is more specific, mandating that vents can handle pressures, temperatures, hydrogen concentrations and radiation levels from a damaged reactor. The enhancements also ensure plant personnel can operate the vents safely if the reactor core is damaged.

The order covers venting scenarios for both “wetwells,” structures meant to condense accident-generated steam and control pressure, and the larger “drywell” structures that surround the reactor. The order requires the 31 plants to complete wetwell venting improvements starting in June 2014 (depending on a plant’s refueling schedule). Plants must also analyze their drywell venting scenarios, and if necessary, install a drywell venting option starting in June 2017.

NRC staff is meanwhile developing a technical evaluation to support rulemaking on filtering, gathering more public input as it completes its analysis. The staff is reportedly considering both the use of a filter to be placed on the vent, as well as a more performance-based approach using existing systems to achieve a similar reduction in radioactive release during an accident. That draft rule and final rule should be ready by March 2017.

Industry has pushed back on the installation of filtered vents, citing NRC estimates that they could cost up to $15 million. Other estimates put costs of equipment at $30 million or more.

Public Comment on Foreign Ownership

On June 10, the NRC called for public comments on issues related to foreign ownership, control, and domination of commercial nuclear power plants.

Currently, the Atomic Energy Act and NRC regulations disqualify any applicant for a nuclear power plant operating license if the applicant is owned, controlled, or dominated by a foreign national, a foreign corporation, or a foreign government.

This March, the NRC denied a petition from Unistar Nuclear Operating Services to review an August 2012 decision by the NRC’s Atomic Safety and Licensing Board that found the company was ineligible to obtain a construction and operation license (COL) for its proposed—and then abandoned—Calvert Cliffs 3 EPR because it was completely foreign-owned. At the time UniStar’s COL application was filed, in 2007, UniStar was a joint venture between Maryland-based Constellation and the French company EDF. In late 2010, EDF bought Constellation’s portion and made UniStar 100% foreign-owned.

And in May, the NRC ruled that a partnership between NRG Energy and Japan’s Toshiba Corp. to build two new ABWR reactors at the South Texas Project outside Bay City, Texas, through the holding company Nuclear Innovation North America (NINA) continues to be dominated by foreign control. Until NINA can come up with a different corporate ownership structure, the NRC said it could not approve the project’s combined COL.

"In recent years, a number of licensing actions before the NRC have involved complex issues of foreign ownership, control and domination. This is likely due to the increased globalization of the electric power industry and complexity of corporate structures generally," the regulator said. The commission directed staff this March to evaluate foreign ownership issues and propose changes, though no specific changes have been proposed.

Written comments are due on Aug. 2 using the federal government’s rulemaking website at www.regulations.gov.

NRC Issues Final Environmental Impact Statement for Watts Bar Unit 2

The NRC on June 7 issued a Final EIS for Tennessee Valley Authority’s (TVA’s) Watts Bar 2 reactor under construction near Spring City, Tenn., concluding there are no environmental impacts that would preclude it from issuing an operating license to the project.

The TVA began Watts Bar 2’s operating license application in 1976, when the NRC’s reactor licensing process involved first applying for a construction permit and then a license. But TVA obtained construction permits for two Watts Bar reactors in 1973, with Unit 1 completing the licensing process and starting operations in 1996. TVA halted construction of Unit 2 in late 1985, and then informed the NRC in August 2007 that it would resume construction of Unit 2. TVA is requesting permission to operate Unit 2, a 1,150-MWe, Westinghouse-designed pressurized water reactor of the same type as Unit 1.

The federally owned TVA issued its own Final Supplemental EIS in 2008. The NRC must complete both safety and environmental reviews before reaching a decision on whether the TVA can begin operating Watts Bar 2, however.

Last week, the NRC increased oversight of the Watts Bar nuclear power plant after citing the plant for violations of requirements for analyzing and preparing for potential flooding. The plant is located on Watts Bar Lake, about 60 miles southwest of Knoxville, and though no actual flooding events have affected the plant, the NRC said plant staff would have been unable to implement flood mitigation procedures within the time specified in those procedures. TVA did not establish flood protection for potential failure of upstream dams, the NRC also found.

Sources: POWERnews, NRC, TVA

Sonal Patel, Senior Writer (@POWERmagazine, @sonalcpatel)