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Sealed source leak test calculator
Enter the wipe result, or the counts and your counter's efficiency, to see whether it meets the 0.005 µCi action level.
Runs in your browser. Nothing you enter is sent or saved.
The rule
Under 10 CFR 35.67, a sealed-source leak test that finds 185 Bq (0.005 µCi) or more of removable contamination means the source must be withdrawn from use right away and stored, disposed of or repaired.
A report is due within 5 days (10 CFR 35.3067). Leak test records are kept for 3 years (10 CFR 35.2067). Agreement States have equivalent rules, which can be stricter. Always follow your license.
From counts to activity
activity (dpm) = (gross cpm − background cpm) ÷ efficiency
The action level of 0.005 µCi equals 11,100 dpm.
Questions
How often are leak tests required?
For medical licensees, generally every 6 months for sealed sources above the exempt thresholds, unless the source's registration says otherwise. Your license conditions decide the schedule.
Can CurieLedger track leak tests and remind us?
Yes. CurieLedger keeps the leak-test schedule, results and the 3-year records, and flags any result at or above the action level. See plans.