LuduminaAT-06 · AT-U2 · Planned
Contamination, irradiation and evidence quality
Learning objectives
Distinguish contamination/irradiation and their hazards; evaluate precautions and the value of peer-reviewed risk evidence.
8463 §§4.4.2.4 / 8464 §§6.4.2.4
DfE single-science pp.43–44 / Combined pp.35–36. Evidence checked 30 September–1 October 2026. Skills: WS1.5,1.6,3.7,3.8.
Explanation
Irradiation exposes an object to radiation; contamination means radioactive material is on or inside it. Removing an external source ends that irradiation but does not remove deposited material. Risk conclusions need exposure data and sound methods, not just a dramatic source label.
Concepts, equations and units: Contamination radioactive material present; irradiation exposure to radiation; risk depends on radiation, dose, exposure and location.
Prediction, demonstration and game exercise
Predict, observe, explain
Compare external source removed with deposited source remaining; analyse supplied evidence without medical claims.
Planned learner game exercise
Audit lab-scenario cards for distance,time,shielding and containment choices; critique a flawed public claim.
Independent practice
Write two safety explanations and evaluate a study’s method, sample and publication status.
Original practice example · Shared
An external sealed source is removed with no material transferred to the object. Was it contaminated merely by exposure?
Show working and model answer
Working / reasoning
Exposure alone is irradiation; no radioactive material has been deposited in this scenario.
Answer
No; it was irradiated, not contaminated.
Exit check and success criteria
Both definitions correct, precautions matched to mechanism and a substantive evidence limitation identified.
During practice, compare the prediction with evidence and give an error-specific prompt. The exit item uses a fresh context or fresh values, answered independently.
Misconceptions, practical links and mastery
Check these misconceptions
Irradiation always makes an object radioactive; contamination ends when the external source is switched off.
Practical preparation
No RP; only simulated/source-based radiation safety tasks.
Virtual preparation and revision only. Required hands-on activities and school records remain separate.
Proposed mastery
0: not yet evidenced. 1: supported. 2: independent exit criteria met. 3: successful changed-context transfer. Advance at 2; revisit with fresh retrieval. These are not GCSE grades.