1. ERMSAR 2012, Cologne March 21 – 23, 2012 Experimental Determination and Analysis of Iodine Mass Transfer Coefficients from THAI Test Iod-23 K. FISCHER, Becker Technologies GmbH, Eschborn (GE) G. WEBER, GRS, Garching (GE) F. FUNKE, G. LANGROCK, AREVA GmbH, Erlangen (GE)

2. ERMSAR 2012, Cologne March 21 – 23, 2012 THAI vessel with general thermal hydraulic instrumentation

3. ERMSAR 2012, Cologne March 21 – 23, 2012 Configuration of THAI facility for I2 mass transfer test (including target values of boundary conditions)

4. ERMSAR 2012, Cologne March 21 – 23, 2012 Air injection port

5. ERMSAR 2012, Cologne March 21 – 23, 2012 Test intervals of stagnant and moving sump water flow

6. ERMSAR 2012, Cologne March 21 – 23, 2012 Iodine mass flow from water surface to air space

7. ERMSAR 2012, Cologne March 21 – 23, 2012 Iodine mass flux from the water surface to the gas space: Conversion of dissolved I 2 to iodide ions I- by surface reaction with submerged steel: Water-side mass transfer coefficient based on unsteady molecular diffusion:

8. ERMSAR 2012, Cologne March 21 – 23, 2012 Average contact time t c for constant radial flow velocity v = 0.35 m/s t c (s)k w (m/s)s (m) Stagnating sump< 7200> 3.5E-7<0.0025 Mixed sump  0.67  3.6E-5  2.4E-5 AIM-3 default-1E-5- Results for contact time, transfer coefficient and film thickness s

9. ERMSAR 2012, Cologne March 21 – 23, 2012

10. Model comparison for iodine mass flow

11. ERMSAR 2012, Cologne March 21 – 23, 2012 Uncertainties of the present analysis: Experimental uncertainties (no explicit measurement of I 2w ; reduction of I 2w by reaction with steel wall; determination of t c ; influence of air flow upon surface exchange during stagnation conditions) Model simplifications (e.g. uniform boundary layer thickness; uniform contact time) Conclusion: Validity of the film renewal model is well confirmed within the error margins of the present experimental data

12. ERMSAR 2012, Cologne March 21 – 23, 2012 Film renewal model or penetration theory Water Atmosphere Bulk iodine concentration c 1 Interface concentration c 1i Concentration boundary layer

13. ERMSAR 2012, Cologne March 21 – 23, 2012 How to determine the contact time t c ? From scaling consideration: t c ~ surface length/velocity From 3-d pool flow simulation: 2-d flow distribution in surface fluid layer with sources and sinks; calculate average surface fluid age a = age = contact time t c, q = areal flow source/sink (1/s), A = age of source/sink flow (source A = 0, sink A = a)