The U.S. Nuclear Regulatory Commission (NRC) on Jan. 31 said it started a Special Inspection to review the circumstances around the loss of off-site power that led to a Unit 2 reactor shutdown on Jan. 30 at Exelon Generation Co.’s two-unit, 2,336 MW Byron nuclear power plant.

The special inspection team will look into how plant equipment responded to the loss of off-site power. The NRC said the team will review the sequence of events and review the plants actions surrounding the incident. The team will also review the plant’s evaluation of what happened, their plan for addressing the cause of the event, and the implementation of their corrective actions.

As of Jan. 31, the NRC said Unit 2 remains in a safe and stable shutdown condition and the diesel generators continue to supply power to the plant as planned for this type of incident. There was a steam release from the non-nuclear side of the plant with trace amounts of tritium. This type of steam release is used by nuclear power plants to release pressure in order to maintain the plant in a stable condition.

The NRC also said doses to the public from this type of release are significantly below even the most stringent Federal protective limits and, therefore, do not pose a risk to public health and safety.

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