04 Protection
Dose-limit remaining
ICRP 103: 20 mSv/y occupational (averaged 5 y, 50 mSv cap), 1 mSv/y public, 1 mSv embryo.
Listen
Listen · English
Simulation
Dose-limit remaining — Change the numbers; the scene follows.
Where it works
Treatment vault
Primary barrier
In the bunker maze and barriers — time, distance, TVL, WUT, and weekly controlled-area dose.
Open this machineFormula
Typical values
Variables
Results
H_left
Remaining
17mSv
used
Fraction used
0.15
Explanation
What it means
Occupational effective-dose limit is 20 mSv per year averaged over 5 years, not exceeding 50 mSv in any single year. Lens of eye 20 mSv/y (after ICRP 118), extremities 500 mSv/y, public 1 mSv/y, embryo-fetus 1 mSv after declaration. This calculator subtracts year-to-date dose from a chosen cap so you can see remaining budget — it is not a legal record. This is a working relation in Radiation protection.
Where it is used
Clinically it sits on the Treatment vault — Primary barrier. In the bunker maze and barriers — time, distance, TVL, WUT, and weekly controlled-area dose. Protection equations are the wall, the occupancy factor, and the badge: time, distance, shielding, and WUT. They turn a room into a legal design.
Treatment vault · Open this machineHow to use it
Enter the cap (default 20) and year-to-date effective dose. Read remaining and the fraction used. Presets: occupational 20, public 1, lens 20, extremity 500, pregnant 1. Change one input and watch the curve and the simulation follow.
Symbols
- H_limLimit20 mSv
- H_ytdYear-to-date3 mSv
Worked example
A typical case from the default values: H_lim = 20 mSv (Limit); H_ytd = 3 mSv (Year-to-date). Substituting into the relation gives H_left = 17 mSv; used = 0.15. These are teaching numbers — align them with your machine.
Typical values give
- H_left = 17mSv
- used = 0.15
Where it comes from
The displayed formula is the working relation. ICRP 103: 20 mSv/y occupational (averaged 5 y, 50 mSv cap), 1 mSv/y public, 1 mSv embryo. Usual reference: ICRP 103 / EU BSS. Derive it in the specialty lesson, then return here to pin the numbers.
Reference: ICRP 103 / EU BSS
Assumptions & limits
Does not implement the 5-year average, planned special exposures, or national variants (US 50 mSv/y TEDE). Skin / extremity / lens must be tracked separately from E. Not a dosimetry-record system.
Pitfalls
Tenth-value layers are for the broad beam in that material and that energy — not a photocopy from another bunker. Occupancy T is not a guess; it is a use pattern. Inverse-square fails against a large scatter source. Does not implement the 5-year average, planned special exposures, or national variants (US 50 mSv/y TEDE). Skin / extremity / lens must be tracked separately from E. Not a dosimetry-record system.
Keep this
Time, distance, shielding — in that order — then calculate the wall. Does not implement the 5-year average, planned special exposures, or national variants (US 50 mSv/y TEDE). Skin / extremity / lens must be tracked separately from E. Not a dosimetry-record system.
In this specialty