RSO Study Guide 2026
Everything you need to pass the RSO exam in one place: the exam format, every topic to study, real practice questions with explanations, flashcards, and full-length practice tests. Free, no sign-up needed.
📋 RSO Exam Format at a Glance
📚 RSO Topics to Study (22)
✍️ Sample RSO Questions & Answers
1. An RSO is working with a source of I-131, which has a half-life of approximately 8 days. If the initial activity is 40 mCi, what will the activity be after 24 days?
24 days equals 3 half-lives (24/8 = 3), so the activity decreases by half three times: 40 → 20 → 10 → 5 mCi.
2. A hospital's pathology waste is found to contain a patient's tissue with measurable I-131 activity. This waste should be:
Tissue containing I-131 is radioactive waste; given I-131's 8-day half-life, decay-in-storage is practical, and disposal must comply with the license and applicable state/NRC regulations.
3. Indirect action in radiation biology refers to:
Indirect action involves radiation ionizing water molecules in cells to produce hydroxyl radicals and other reactive species that then diffuse to and damage DNA.
4. A whole-body counter is used to measure:
A whole-body counter uses large-volume gamma detectors positioned around the body to detect and quantify internally deposited gamma-emitting radionuclides in organs and tissues.
5. Which nuclear process results in the emission of a positron (β+)?
Beta-plus decay occurs when a proton converts to a neutron inside the nucleus, emitting a positron and a neutrino.
6. Liquid scintillation waste containing H-3 or C-14 may be disposed of by sanitary sewer only if:
NRC 10 CFR 20.2003 and license conditions specify allowable concentrations and total annual discharge quantities for sewer disposal; both the concentration and total limits must be met.