According to regulations, which of the following is NOT a reportable event to NRC?

The correct choice reflects an understanding of what constitutes reportable events under the regulations regarding pipeline safety and oversight. The regulations specify certain events that must be reported to the National Response Center (NRC). Events such as the release of natural gas from a pipeline, fatal incidents, and emergency shut-ins are indeed conditions that require reporting due to their potential impact on safety and emergency response protocols.

In contrast, property damage or lost gas exceeding $10,000 may not necessarily require direct reporting to the NRC under all circumstances, especially if it is not correlated with an immediate danger to life or health. Unlike releases of hazardous materials, fatalities, and emergency situations, the monetary threshold related to property damage does not singularly trigger a mandatory report unless it coincides with one of the more critical thresholds that do. Therefore, this choice appropriately identifies an event that may not meet the criteria for mandatory reporting to the NRC, emphasizing the need to distinguish between urgency in safety contexts and federal reporting obligations.