Nuclear Security & Deterrence Vol. 19 No. 44
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Nuclear Security & Deterrence Monitor

Article 7 of 13

November 20, 2015

NRC Cites Welding Violation at MOX Facility

By Alissa Tabirian

Staff Reports
NS&D Monitor
11/20/2015

Some welding on the Savannah River Site’s Mixed Oxide Fuel Fabrication Facility (MFFF) may be redone following a violation detected during an inspection last month. The Nuclear Regulatory Commission noted that design documents for work at the MFFF included inadequate welding measurements based on standards established by the American Welding Society. The MFFF is the main facility for the nation’s MOX project, through which the U.S. intends to dispose of 34 metric tons of weapon-usable plutonium. The MOX project is expected to accomplish the feat, required under a bilateral accord with Russia, by converting the plutonium into commercial nuclear fuel.

The issue is associated with a minor design error that resulted in a limited number of welds to be slightly below code requirements. A ground and sorted pellet storage unit glove box and a number of shield panels at the MFFF were installed with quarter-inch welds. But the American Welding Society requires welding of safety-related steel that is thicker than three-quarters of an inch to have a minimum weld size of five-sixteenths of an inch. The discrepancy caused the NRC to cite a Level 4 violation, the lowest the agency can give. The NRC wrote that the violation "will result in the need to perform a code deviation or rework of the welds."

The NRC reported that CB&I AREVA MOX Services, the contractor leading construction of the MFFF, has already started making corrective actions and that the issue will be treated as a non-cited violation. The corrective actions are expected to be completed by the end of the year.

Issues looming over the MFFF have MOX supporters and naysayers conflicting on how much work the contractor has to redo. CB&I AREVA recently reported that there is only a need for 2.5 percent rework at the facility, including welding, piping, and other construction issues. But Ed Lyman, a senior scientist with the Union of Concerned Scientists, said he agrees with the Department of Energy on MOX being plagued by at least a 25 percent rework rate. Lyman said the minor violation points to the even bigger issue of longtime problems at the MFFF, arguing that taxpayer dollars are not being spent efficiently. "This welding issue could be the tip of the iceberg," Lyman said. "We’re just hoping DOE will have a deeper investigation into what’s going on."

Welding-related concerns at the MFFF were also documented in a July 23 report from the NRC. While the regulatory agency found no violations or deviations, it did point out an unresolved item associated with potentially inadequate welds. The potential inadequacy was on the pre-cast floor panel ledgers in the aqueous polishing building, a facility that will be used to remove impurities from the feed plutonium. The issue was not severe enough for the NRC to document it as a violation.

The taxpayer dollars Lyman referenced have also been a controversial factor since construction of the MOX plant began in 2007. To date, about $5 billion has been spent on the project. Cost projections in reports mandated by Congress and the Department of Energy have concluded that the life-cycle cost of the MOX program will be least $51 billion under sequestration if annual funding levels stay between $345 million and $400 million. For MOX to be truly efficient, DOE Secretary Ernest Moniz previously said it would cost more than $1 billion a year – a rate he believes Congress will not endorse.

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Weapons Complex Vol. 26 No. 44
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Weapons Complex Monitor

Article 12 of 15

November 20, 2015

NRC Cites Welding Violation at MOX Facility

By Brian Bradley

Staff Reports
WC Monitor
11/20/2015

Some welding on the Savannah River Site’s Mixed Oxide Fuel Fabrication Facility (MOX) may be redone following a violation detected during an inspection last month. The Nuclear Regulatory Commission noted that design documents for work at MOX included inadequate welding measurements based on standards established by the American Welding Society. The plant is the main facility for the nation’s MOX project, through which the U.S. intends to dispose of 34 metric tons of weapon-usable plutonium. The MOX project is expected to accomplish the feat, required under a bilateral accord with Russia, by converting the plutonium into commercial nuclear fuel.

The issue is associated with a minor design error that resulted in a limited number of welds to be slightly below code requirements. A ground and sorted pellet storage unit glove box and a number of shield panels at MOX were installed with quarter-inch welds. But the American Welding Society requires welding of safety-related steel that is thicker than three-quarters of an inch to have a minimum weld size of five-sixteenths of an inch. The discrepancy caused the NRC to cite a Level 4 violation, the lowest the agency can give. The NRC wrote that the violation "will result in the need to perform a code deviation or rework of the welds."

The NRC reported that CB&I AREVA MOX Services, the contractor leading MOX construction, has already started making corrective actions and that the issue will be treated as a non-cited violation. The corrective actions are expected to be completed by the end of the year.

Issues looming over the project have MOX supporters and naysayers conflicting on how much work the contractor has to redo. CB&I AREVA recently reported that there is only a need for 2.5 percent rework at the facility, including welding, piping, and other construction issues. But Ed Lyman, a senior scientist with the Union of Concerned Scientists, said he agrees with the Department of Energy on MOX being plagued by at least a 25 percent rework rate. Lyman said the minor violation points to the even bigger issue of longtime problems at MOX, arguing that taxpayer dollars are not being spent efficiently. "This welding issue could be the tip of the iceberg," Lyman said. "We’re just hoping DOE will have a deeper investigation into what’s going on."

Welding-related concerns at MOX were also documented in a July 23 report from the NRC. While the regulatory agency found no violations or deviations, it did point out an unresolved item associated with potentially inadequate welds. The potential inadequacy was on the pre-cast floor panel ledgers in the aqueous polishing building, a facility that will be used to remove impurities from the feed plutonium. The issue was not severe enough for the NRC to document it as a violation.

The taxpayer dollars Lyman referenced have also been a controversial factor since construction of the MOX plant began in 2007. To date, about $5 billion has been spent on the project. Cost projections in reports mandated by Congress and DOE have concluded that the life-cycle cost of the MOX program will be least $51 billion under sequestration if annual funding levels stay between $345 million and $400 million. For MOX to be truly efficient, DOE Secretary Ernest Moniz previously said it would cost more than $1 billion a year – a rate he believes Congress will not endorse.

Comments are closed.