1. EDMS v.1
02/07/2013
General trends in ventilation of radiation zones from the viewpoint of public exposure
P. Vojtyla / DGS-SEE-XP

2. Yield per primary proton
EDMS v.1
02/07/2013
Yield per primary proton

3. Produced radioactivity
EDMS v.1
02/07/2013
Produced radioactivity

4. A closed zone: The worst case for RP
EDMS v.1
02/07/2013
A closed zone: The worst case for RP

5. Resulting exposure Annual effective dose E (Sv);
EDMS v.1
02/07/2013
Resulting exposure
Annual effective dose E (Sv);
Radio-toxicity mixes the cards further;
Radiation type and energy;
Physicochemical behaviour;
Human metabolism;
Half-life;
For exposure type resulting in a committed effective dose, short half-life leads to higher activity but the committed dose tends to be smaller with shorter half-life;
Topological arrangement and wind patterns;
Habits of the local population.

6. Wind rose (2011, BA4) To find the maximum Will not be straightforward
EDMS v.1
02/07/2013
Wind rose (2011, BA4)
NW boundary of the site
To find the maximum
Will not be straightforward

7. Hypothetical house – NW (250 m)
EDMS v.1
02/07/2013
Hypothetical house – NW (250 m)
Short-lived gases:
The usual problem

8. Hypothetical house – W (300 m)
EDMS v.1
02/07/2013
Hypothetical house – W (300 m)

9. Hypothetical house – N (450 m)
EDMS v.1
02/07/2013
Hypothetical house – N (450 m)

10. Waste dump: In one of the main wind directions but far away (620 m)
EDMS v.1
02/07/2013
Waste dump: In one of the main wind directions but far away (620 m)

11. Conclusions (1) Completely isolated zones are difficult to realize;
EDMS v.1
02/07/2013
Conclusions (1)
Completely isolated zones are difficult to realize;
Some air extraction is necessary to keep dynamic confinement;
The governing dynamics is such that the prevailing part of the exposure is due to short-lived radioactive gases;
Namely: 11C (20 min), 13N( 11 min), 15O (2 min), 14O (1.2 min), 41Ar (1.8 h);

12. EDMS v.1
02/07/2013
Conclusions (2)
The only way of reducing the activity of the short-lived gases is to delay them before release;
The aerosol-bound radioactivity is efficiently retained by aerosol filters – best in a continuous way in a semi-closed system;
Attention on condensation water of such closed systems – high tritium concentrations may result;
Use an evaporator (PR issue).
Experience from CNGS