Ameren Missouri is disputing a violation it received for its Callaway County Nuclear Plant, following a September U.S. Nuclear Regulatory Commission inspection.
The NRC released the inspection results on Oct. 12. The inspection was a problem identification and resolution inspection. The inspection team examined the plant to "evaluate its effectiveness in identifying, prioritizing, evaluating, and correcting problems," according to the NRC report. The inspection team also confirmed that NRC regulations were being followed.
The disputed violation is a non-cited violation related to "the failure to perform required inservice testing of air-operated residual heat removal heat exchanger outlet and bypass valves," according to an NRC document.
The violation alleges that the Callaway plant did not perform required testing for four pneumatically operated valves. This is a result of incorrectly classifying them as passive valves, according to the NRC report.
A pneumatically operated valve, also known as an air-operated valve, is defined by Humphrey Products as a valve that utilizes air pressure to controlled compressed air, liquids or gas with a pneumatic system.
A passive valve is defined in a Micromachines journal article as an "alternative solution for effective flow control in a microfluidic system, and it usually relies on a microchannel structure or natural effect to regulate the flow rate."
In the September inspection report , the NRC inspection team recorded three non-cited violations. All three were of "very low safety significance," according to the NRC's report.
A non-cited violation with the NRC is documented as such in inspection reports to establish a public record, but are not cited in Notices of Violation, according to NRC documents. Notices of Violation typically require a written response.
The other two non-cited violations were "failure to translate residual heat removal design specifications into procedures and instructions" and "failure to assess operability of residual heat removal in low MODES with one train of essential service water unavailable.
The NRC inspection team discussed the findings of the inspection with members of the Callaway plant staff.
The NRC is reviewing if the violation can be disputed. A decision will be reached within 90 days of Nov. 14.
Fadi Diya, senior vice president and chief nuclear officer with Ameren Missouri, filed the dispute. He has held this position since 2014.