_____ and _____ ECL actions are taken before reaching the off-site limits of 10 CFR 20.

• A. Unusual Event and Alert
• B. Site Area Emergency and General Emergency
• C. Notification of Unusual Event and General Emergency
• D. Alert and Site Area Emergency

Answer: (A)

When radiological conditions are developing but not yet posing a public health risk, events are categorized at the lower Emergency Classification Levels. Unusual Event and Alert are the on-site levels that trigger the plant’s internal response, increased monitoring, and on-site protective actions while staying within the public dose limits. They are used to manage the situation before off-site consequences are possible, and they don’t require implementing off-site protective actions or evacuations. Higher levels, such as Site Area Emergency or General Emergency, are reserved for conditions that could lead to significant releases affecting the public, triggering off-site notifications and protective actions. So, Unusual Event and Alert are the appropriate early actions taken before reaching the off-site limits defined in 10 CFR 20.