Just as preliminary findings from a Nuclear Regulatory Commission special inspection noted three safety violations related to installation of systems at the Vogtle nuclear expansion site, Georgia Power has pushed back the in-service dates for the new units by several months.
Launched June 21, the NRC “special inspection” sought to determine reasons behind needed construction remediation work of installed electrical cable raceway systems at the Vogtle Unit 3 project. The inspection also sought to assess the utility’s overall quality assurance processes.
In its Aug. 25 announcement of findings, the agency stated “inspectors found that Southern Nuclear did not adequately separate safety and non-safety-related cables for reactor coolant pumps and equipment designed to safely shut down the reactor.”
The most serious of the three violations was related to Southern Nuclear Co.’s (SNC) installation of Class 1E cables and associated raceways. Specifically, the agency found “the licensee failed to promptly identify that cable separation was not maintained in accordance with” standards, and “failed to promptly identify widespread deficiencies in installation of seismic supports and structural components, and failed to timely correct these issues.”
The federal agency also cited Southern Nuclear for two other less severe violations: failing to maintain “1-inch vertical and horizontal cable separation between safety-related electrical divisions and non-safety-related electrical cables inside switchgear cabinets;” and “failure to install seismic Category I electrical raceways and connections in accordance with applicable instructions, procedures, and drawings.”
Georgia Power addressed the violations in its 25th semi-annual construction monitoring report, which it submitted to the Georgia Public Service Commission on Aug. 31.
In its report, the utility noted that, “The violations identified in the NRC’s report were already captured within the site corrective action program prior to the commencement of the special inspection, and work has been underway for months to resolve these issues.”
The utility added that SNC had investigated the issue prior to the start of the NRC inspection, and had self-reported issues related to the Unit 3 cable systems.
Schedule Delays Confirmed
Outside project monitors have long testified to lagging construction progress at the Vogtle site, where Units 3 and 4 were originally estimated to be operational by 2016 and 2017, respectively. Earlier this year, for example, Donald Grace, of Vogtle Monitoring Group, estimated a further 7- to 9-month delay for each unit.
As a result, Grace estimated, instead of achieving commercial operation by November 2021, Unit 3 may not meet that milestone until roughly June to August 2022, or “even later,” with Unit 4’s COD likely coming as late as June 2023.
The utility isn’t quite as pessimistic.
While admitting to challenges related to “construction productivity, construction remediation work, the pace of system turnovers, Spent Fuel Pool repairs, and the timeframe and duration for HFT [Hot Functional Testing] and other testing,” Georgia Power now projects that Unit 3 could reach commercial operation by the second quarter of 2022—just a few months later than the previous target of March 2022. The utility did note, however, that “any further delays could result in a later in-service date.”
In the case of Unit 4, where Georgia Power has been targeting an in-service date of November 2022, the utility told regulators that date “primarily depends on overall construction productivity and production levels significantly improving, as well as appropriate levels of craft labor, particularly electricians and pipefitters, being added and maintained.”
Admitting to “minimal margin” in its Unit 4 construction plan, Georgia Power also advised state regulators that this new unit may not achieve commercial operation until the first quarter of 2023. As with Unit 3, however, the utility added that a later in-service date could also occur with Unit 4.