WG Leader: Juan Carlos Mora IAEA Scientific Secretary: Diego Telleria Modelling and Data for Radiological Impact Assessments “MODARIA” WG 5 – Uncertainty and variability analysis for assessments of radiological impacts arising from routine discharges of radionuclides. Vienna. November,11th – 15th, 2013
MODARIA. WG 5 – Routine Discharges Brief TSO, Regulators and Industry Vienna 2012 – 22 Participants (16 countries) - 13 presentations Madrid 2013 – 20 Participants (13 countries) - 12 presentations (2 code courses) Vienna 2013
MODARIA. WG 5 – Routine Discharges The proposal Objective Development of guidance on uncertainty analysis for dose assessment in routine releases, including interpretation of results
MODARIA. WG 5 – Routine Discharges The proposal Tasks (1) Identify possible tools and methods for uncertainty and variability analysis applicable to dose assessments methods and codes for routine radioactive discharges. (2) Identify cases and scenarios where information on uncertainty and variability of parameters is available for the testing of methodologies. (a) Definition of realistic scenario for a hypothetical NPP based on information from INPRO or EMRAS II projects. (b) Definition of a realistic scenario based in French NPP (Chinon).
MODARIA. WG 5 – Routine Discharges The proposal Tasks (3) Discuss the realism of the models and scenarios applied. (4) Discuss the sources of uncertainty and available methods which allow their quantification. (5) Elaborate methods and procedure for performing a priori sensitivity analysis to identify key parameters in the used models.
MODARIA. WG 5 – Routine Discharges The proposal Tasks (6) Discuss the distributions of parameters and data to be used in the different scenarios and codes. (7) Identify correlation factors among different parameters used in the models. (8) Explain the role of environmental monitoring data in uncertainty analysis processes.
MODARIA. WG 5 – Routine Discharges The proposal Tasks (9) Carry out exercises with the different codes in the scenarios defined. (a) Sensitivity analysis to be carried out in each of the exercises. (b) Discuss the different methods used in the evaluations carried out, focusing on the choice of parameters probability distribution functions (pdfs) and correlations among them. (10) Discuss the communication of results of calculations which include uncertainty analysis to the different stakeholders (regulators, public … ).
MODARIA. WG 5 – Routine Discharges Methodology for the assessment • What are the steps for a dose assessment, and how they are affected by the purpose of the assessment? • When should uncertainties be included? • When is enough a qualitative discussion? • When is necessary a quantitative determination? • When should variabilities be included? • Should some data be fixed in advance?
MODARIA. WG 5 – Routine Discharges Identification of tools 6 codes which include uncertainties analysis and were prepared for routine discharges were identified: CROM, IMPACT, CRYSTAL BALL, SU_MMC, SYMBIOSE, (MCMC) Brief overview was provided for 4 of them in Madrid (2 freely distributed to the group)
MODARIA. WG 5 – Routine Discharges Identification of tools SU_MMC
MODARIA. WG 5 – Routine Discharges Identification of tools
MODARIA. WG 5 – Routine Discharges Identification of tools
MODARIA. WG 5 – Routine Discharges Identification of tools
MODARIA. WG 5 – Routine Discharges Identification of scenarios Table 1.- Chinon NPP annual liquid releases - year 2011 Radionuclides GBq y -1 3 H 54200 14 C 16.5 54 Mn 0.01 60 Co 0.072 58 Co 0.057 110m Ag 0.158 123m Te 0.009 124 Sb 0.010 125 Sb 0.028 131 I 0.011 134 Cs 0.010 137 Cs 0.011
MODARIA. WG 5 – Routine Discharges Identification of scenarios Table 1.- Annual discharges of radionuclides Q from an APR 1400 NPP, as used for estimating annual dose via the atmospheric pathway for the INPRO ENV project Radionuclide Q , Bq·a -1 Radionuclide Q , Bq·a -1 Radionuclide Q , Bq·a -1 Table 5.- Values for crop and soil exposure periods, delay times, and H-3 3.44E+13 Kr-88 4.07E+11 Xe-135m 1.48E+11 other vegetable parameters [3], [9] C-14 (CO 2 ) 2.70E+11 Sr-89 5.92E+06 Xe-138 1.11E+11 Ar-41 1.26E+12 Sr-90 2.33E+06 I-131 1.37E+09 Parameters for Cr-51 3.59E+06 Zr-95 3.70E+05 I-132 5.92E+09 triangular Fixed Mn-54 2.11E+06 Nb-95 1.55E+06 I-133 4.07E+09 Parameter Symbol Unit distribution value Fe-59 1.04E+06 Ru-103 6.29E+05 I-134 9.62E+09 Low Base High Co-57 3.03E+05 Ru-106 2.89E+04 I-135 7.40E+09 time period that crops are forage grasses t e (1) 30 Co-58 1.78E+07 Sb-125 2.26E+04 Cs-134 1.78E+06 exposed to contamination d food crops t e (2) 60 during the growing season Co-60 4.07E+06 Xe-131m 2.11E+13 Cs-136 1.22E+06 forage t h (1) 0 Kr-85 1.81E+14 Xe-133 3.00E+13 Cs-137 3.33E+06 stored feed for Kr-85m 2.22E+11 Xe-133m 3.70E+11 Ba-140 1.55E+05 t h (2) 90 delay (hold-up) time that animals represents the time interval Kr-87 1.48E+11 Xe-135 1.59E+12 Ce-141 4.81E+05 leafy vegetables d 0 1 7 between harvest and root crops 0 14 28 consumption of the food t h (3) non-leafy 0 14 28 vegetables average time between milk t m d 0 1 7 collection and human meat t f d 7 20 30 consumption leafy vegetables 0.076 root crops 0.143 average dry matter content non-leafy 0.135 vegetables fraction of the year that animals consume fresh f p 0.7 pasture vegetation kg·d – 1 milk cow Q m 16 amount of feed (dry matter) kg·d – 1 consumed by the animal meat cow Q f 12
MODARIA. WG 5 – Routine Discharges Identification of parameters and distributions Table 2.- Kd in the abiotic freshwater modules (L.kg-1 dry weight) Table 3.- Soil Kd in the agricultural modules (L.kg-1 dry weight) Element Distribution Min GM Max Element Distribution Min GM Max 5.4x1 Ac Log uniform 450 03 Log normal 1.6x10 8.5x10 4.5x10 Ag 4 4 5 truncated 1.5x1 Ag Log uniform 36 04 Log normal 3.8x10 1.2x10 3.9x10 Am 3 5 6 truncated Log normal 9.7x1 Am 70 2600 truncated 04 Log normal 1.5x10 2.0x10 2.6x10 Ba truncated 2 3 4 3.0x1 As Log uniform 25 03 Log normal 3.2x10 4.2x10 5.4x10 Be 3.0x1 3 4 5 truncated Be Log uniform 240 03 Log normal 2.8x10 2.2x10 1.7x10 Ce 1.5x1 4 5 6 truncated Bi Log uniform 120 03 7.0x10 Cm Log uniform 10 Br Log uniform 15 180 4 Log normal Ca 0.69 8 92 Log normal 3.0x10 4.4x10 6.3x10 truncated Co 3 4 5 truncated Log normal 3.1x1 Ce 46 1200 Log normal 2.9x10 1.0x10 truncated 04 Cs 830 truncated 4 6 Log normal 1.3x1 Cm 644 9300 truncated 05
MODARIA. WG 5 – Routine Discharges Role of measurement uncertainties • Uncertainties and variabilities • Interpretation of environmental monitoring results • Statistics limitations • Surveys in populations
MODARIA. WG 5 – Routine Discharges Correlations
MODARIA. WG 5 – Routine Discharges A priori sensitivity analysis • Use of fixed percentage variations • Use of predefined pdfs • All or some parameters • Identification of more sensitive parameters • Reduction of total uncertainty by improving the knowledge of more sensitive parameters
MODARIA. WG 5 – Routine Discharges Communication issues How should the dose assessments be communicated: • Operator Regulator • Comunication to the public, involvement of stakeholders • Risk comunication
MODARIA. WG 5 – Routine Discharges Products “MODARIA WG5: Towards a practical guidance for the performance of uncertainty calculations in the assessment of routine releases. ” Authors: Juan Carlos Mora, Diego Tellería, Adriana Curti, Christophe Mourlon, Iurii Bonchuk, Fabiene Vermorel , Laura Marang, Sohan Chouhan, Benjamin Zorko, Juraj Duran, Ahmed Alneaimi, Anna Maria Blixt Buhr, Pavol Chylý, Goran Ivanis, Charlotte Lager, Beatriz Robles, Ann-Christin Hägg, Maria Elizabete Figueiredo, Cíntia Melazo Dias, Jarmila Bohunova, Fabricio Fiengo Perez, Mikhail Iosjpe, Pawel M. Krajewski, Jige Shen, Andrew Woodruffe
MODARIA. WG 5 – Routine Discharges The Forge
Thank you! MODARIA. WG 5 – Uncertainty and variability analysis for assessments of radiological impacts arising from routine discharges of radionuclides
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