Save for later Print Download Share LinkedIn Twitter Workers at Southern Nuclear's (SNC) Vogtle-3 newbuild may have signed off on quality inspection reports at some 67 locations where electrical cable trays were installed without properly determining if they were overloaded, according to the US Nuclear Regulatory Commission's (NRC) latest inspection report for the twin-unit AP1000 newbuild in Georgia. The report also cites drilling and installation work by unqualified subcontractors. The Aug. 6 report covers the latest three-month period of Inspections, Tests, Analysis and Acceptance Criteria (Itaac) and quality assurance (QA) program inspections by regional and resident inspectors, all of which need to be successfully closed out in order for the unit to be green-lighted for operation. The agency is expected to release at the end of August the results of a special inspection focused on Unit 3's electrical cable raceway system, and why construction remediation work on that system proved necessary. But the findings in the latest report suggest what might have prompted that special inspection and implies, without specifically saying so, that similar problems could exist at Unit 4, which Southern says is 84% complete. Southern Chairman and CEO Tom Fanning told investment analysts in a first-half earnings call Jul. 29 that 208 Itacc items have been submitted to the NRC and that "we will submit the remaining 191 as we approach fuel load." He was notably circumspect about the special inspection, announced Jun. 21, saying only that it involved "electrical quality issues that we had identified earlier this year and the remediation efforts that are under way." He also said that the NRC's "onsite inspection is complete, and we expect the NRC's report to be published within a couple of months." An NRC Region II spokesperson affirmed that timing, telling Energy Intelligence in an email this week that, "You can expect the report by the end of the month." The latest report suggests that the special investigation may have been prompted at least in part by a discovery on May 26 that onsite field engineers and quality assurance personnel failed to "verify maximum loading exceedance for cables exiting" a cable tray in a location identified only as Room 12313. The report adds that while "the condition" was initially identified in this one area, "66 other locations were also identified as a result of SNC's investigation to determine the extent of the condition." The problem was brought to the attention of Southern's project licensing manager, and other licensee and contractor staff the same day it was discovered. The NRC report, citing a corrective action report on the problem, states that "these possible impacted locations were walked down and reviewed" against design requirements "and the configurations at these locations were determined to be acceptable." Asked about the location of the initial incident and what "condition" referred to, an NRC spokesperson told Energy Intelligence in an email: "The term 'Condition' refers to Southern’s failure to verify by analysis/calculation that cables exiting cable trays by way of the side rails did not exceed load-bearing design requirements for the cable tray. Room 12313 is part of the Nuclear Island Building. Southern continues to perform walkdowns and reviews of impacted locations as part of its remediation work." "The fact that they identified 66 others strongly suggests at least one [cable tray] was overloaded," reactor safety expert Dave Lochbaum told Energy Intelligence. "That homework suggests they [NRC] needed to send out the troops." Lochbaum also suggested that the lack of subcontractor oversight -- likely exacerbated by incentives for closing out work packages -- may have extended to Unit 4 and that the special inspection report may prove a "litmus test for how Unit 4 will be affected." Other Violations Besides the electrical issues, the NRC's report cited two other cases involving poor to nonexistent oversight, including one on Feb. 20 in which a subcontractor "not qualified to perform welding on safety-related structures" welded three sets of fire extinguisher brackets on the Unit 3 containment vessel using a drawing "that did not specify welding to the containment vessel," but rather "allowed for mounting to steel columns, permanent formwork plate, embedment plates, and modules." In a second incident, a subcontractor "who was not qualified to drill penetrations and install material into Safety Class C concrete structures ... had been doing so under two separate contracts." According to a construction industry source, "The usual methodology for anchoring in structural concrete is to scan the area with X-ray or GPR scan, identify the latticing of the re-bar, layering of top and bottom bars, send that scan to a project structural engineer who then gives the red or green light on drilling/anchoring." But "it sounds like they didn't do that." The incident was identified on Nov. 1, 2019 by the licensee but "no corrective actions" were taken "to address the behaviors" and the matter was closed on Aug. 20, 2020. "Approximately five months later, on Jan. 21, 2021, a subcontractor (one of the five unqualified subcontractors identified by the effectiveness review) who was not qualified to drill penetrations and install material into Safety Class C concrete structures ... drilled into the Unit 3 auxiliary building rooftop and installed expansion anchors without work instructions approved for the activity. Edge boxes were fabricated and installed by subtier sheet metal workers without an approved work package or an approved" Asme (American Society of Mechanical Engineers) quality assurance program as prescribed under mechanical engineering standards for nuclear facilities. Although these three findings were deemed of "low safety significance" or green on the agency's Action Matrix, the report described the welding incident "of more than minor safety significance ... because it rendered the quality of the containment vessel unacceptable or indeterminant and required substantive corrective action." Similarly the drilling incident was "more than minor" because "it represented a substantive failure to establish or implement" an adequate quality oversight function. Both issues are still "open" pending NRC reviews to verify adequate corrective actions so that the relevant Itaac items can be closed. The cable tray issue is considered "an Unresolved Item" subject to a determination as to "whether the performance deficiency is material to the acceptance criteria of an Itaac," according to the report. Besides poor oversight, the Vogtle project has been plagued by high craft labor attrition rates, particularly among electricians. As a result, Fanning said that Unit 4 is now being staffed separately from Unit 3, and compensation rates for electricians were raised. "In recent weeks we have seen positive staffing trends, driven in part by offering the enhanced electrician compensation, which has helped to mitigate further schedule impacts." Also, in terms of scheduling "Unit 4 is on an independent path from Unit 3." He added that there was "like a two-hour, three-hour-long argument with people on the site" about whether a revised operational date for Unit 4 should be in the first or second quarter of 2023 "and we landed on the first quarter." Vogtle-3 is now targeted for start-up in the second quarter of 2022 instead of the first (NIW Jul.30'21). Stephanie Cooke, Washington
