In the RES-2 Unit risk assessment, which option represents the Moderate Degree of Risk threshold?

• A. A+B <= 50 cGy
• B. A+B <= 100 cGy
• C. A+B <= 200 cGy
• D. A+B <= 300 cGy

Answer: (B)

In this risk assessment, thresholds divide exposure into levels of risk based on the sum of the two dose components, A and B. The Moderate Degree of Risk is defined by a boundary at 100 cGy, so any combined exposure up to 100 cGy falls into the moderate category. The 100 cGy line is inclusive, meaning exactly 100 cGy is still considered moderate. This creates a clear cutoff that helps determine when actions appropriate to moderate risk should be taken and when higher risk levels would require stronger controls. Values like 50 cGy, 200 cGy, or 300 cGy would place the exposure in different risk categories, so they do not define the moderate threshold.