Radiation calculations: decay, distance, shielding
ASP written lesson, 8 min read. ASP Domain 1: Mathematical Calculations
AI-drafted from the cited rules and fact-checked against them. Study aid, not site-specific safety advice. The official rule controls.
What you'll learn
- Apply the decay equation and half-life to find remaining activity
- Use the inverse square law to estimate intensity at a new distance
- Calculate shielded intensity by counting half-value layers
- Combine distance and shielding in one exposure-reduction problem
- Avoid the common setup and unit errors in radiation math
What this lesson covers
Three equations cover most radiation calculation questions: radioactive decay, the inverse square law for distance, and shield attenuation with half-value layers. This lesson shows how to set up each one, count half-value layers, and avoid the unit and ratio mistakes that cost points on the exam.
This lesson is included with a pass
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Try the free radiation calculations: decay, distance, shielding practice questions