WG 5 Uncertainty and variability analysis for assessments of - - PowerPoint PPT Presentation

▶
wg 5 uncertainty and variability analysis for assessments
SMART_READER_LITE
LIVE PREVIEW

WG 5 Uncertainty and variability analysis for assessments of - - PowerPoint PPT Presentation

Aug 24, 2023 299 likes •533 views

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

slide-1
SLIDE 1

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.

WG Leader: Juan Carlos Mora IAEA Scientific Secretary: Diego Telleria

  • Vienna. November,11th – 15th, 2013
slide-2
SLIDE 2
  • 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

slide-3
SLIDE 3
  • MODARIA. WG 5 – Routine Discharges

The proposal

Objective Development of guidance on uncertainty analysis for dose assessment in routine releases, including interpretation of results

slide-4
SLIDE 4
  • 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

  • n

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).

slide-5
SLIDE 5
  • 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.

slide-6
SLIDE 6
  • 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.

slide-7
SLIDE 7
  • 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…).

slide-8
SLIDE 8
  • 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?
slide-9
SLIDE 9
  • 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)

slide-10
SLIDE 10
  • MODARIA. WG 5 – Routine Discharges

Identification of tools

SU_MMC

slide-11
SLIDE 11
  • MODARIA. WG 5 – Routine Discharges

Identification of tools

slide-12
SLIDE 12
  • MODARIA. WG 5 – Routine Discharges

Identification of tools

slide-13
SLIDE 13
  • MODARIA. WG 5 – Routine Discharges

Identification of tools

slide-14
SLIDE 14
  • MODARIA. WG 5 – Routine Discharges

Identification of scenarios

Radionuclides GBq y-1

3H

54200

14C

16.5

54Mn

0.01

60Co

0.072

58Co

0.057

110mAg

0.158

123mTe

0.009

124Sb

0.010

125Sb

0.028

131I

0.011

134Cs

0.010

137Cs

0.011 Table 1.- Chinon NPP annual liquid releases - year 2011

slide-15
SLIDE 15
  • MODARIA. WG 5 – Routine Discharges

Identification of scenarios

Radionuclide Q, Bq·a-1 Radionuclide Q, Bq·a-1 Radionuclide Q, Bq·a-1 H-3 3.44E+13 Kr-88 4.07E+11 Xe-135m 1.48E+11 C-14 (CO2) 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 Cr-51 3.59E+06 Zr-95 3.70E+05 I-132 5.92E+09 Mn-54 2.11E+06 Nb-95 1.55E+06 I-133 4.07E+09 Fe-59 1.04E+06 Ru-103 6.29E+05 I-134 9.62E+09 Co-57 3.03E+05 Ru-106 2.89E+04 I-135 7.40E+09 Co-58 1.78E+07 Sb-125 2.26E+04 Cs-134 1.78E+06 Co-60 4.07E+06 Xe-131m 2.11E+13 Cs-136 1.22E+06 Kr-85 1.81E+14 Xe-133 3.00E+13 Cs-137 3.33E+06 Kr-85m 2.22E+11 Xe-133m 3.70E+11 Ba-140 1.55E+05 Kr-87 1.48E+11 Xe-135 1.59E+12 Ce-141 4.81E+05 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

Parameter Symbol Unit Fixed value Parameters for triangular distribution Low Base High time period that crops are exposed to contamination during the growing season forage grasses te(1) d 30 food crops te(2) 60 delay (hold-up) time that represents the time interval between harvest and consumption of the food forage th(1) d stored feed for animals th(2) 90 leafy vegetables th(3) 1 7 root crops 14 28 non-leafy vegetables 14 28 average time between collection and human consumption milk tm d 1 7 meat tf d 7 20 30 average dry matter content leafy vegetables 0.076 root crops 0.143 non-leafy vegetables 0.135 fraction of the year that animals consume fresh pasture vegetation fp 0.7 amount of feed (dry matter) consumed by the animal milk cow Qm kg·d–1 16 meat cow Qf kg·d–1 12

Table 5.- Values for crop and soil exposure periods, delay times, and

  • ther vegetable parameters [3], [9]
slide-16
SLIDE 16
  • MODARIA. WG 5 – Routine Discharges

Identification of parameters and distributions

Element Distribution Min GM Max Ag Log normal truncated 1.6x10

4

8.5x10

4

4.5x10

5

Am Log normal truncated 3.8x10

3

1.2x10

5

3.9x10

6

Ba Log normal truncated 1.5x10

2

2.0x10

3

2.6x10

4

Be Log normal truncated 3.2x10

3

4.2x10

4

5.4x10

5

Ce Log normal truncated 2.8x10

4

2.2x10

5

1.7x10

6

Cm Log uniform 10 7.0x10

4

Co Log normal truncated 3.0x10

3

4.4x10

4

6.3x10

5

Cs Log normal truncated 830 2.9x10

4

1.0x10

6

Table 2.- Kd in the abiotic freshwater modules (L.kg-1 dry weight)

Element Distribution Min GM Max Ac Log uniform 450 5.4x1 03 Ag Log uniform 36 1.5x1 04 Am Log normal truncated 70 2600 9.7x1 04 As Log uniform 25 3.0x1 03 Be Log uniform 240 3.0x1 03 Bi Log uniform 120 1.5x1 03 Br Log uniform 15 180 Ca Log normal truncated 0.69 8 92 Ce Log normal truncated 46 1200 3.1x1 04 Cm Log normal truncated 644 9300 1.3x1 05

Table 3.- Soil Kd in the agricultural modules (L.kg-1 dry weight)

slide-17
SLIDE 17
  • MODARIA. WG 5 – Routine Discharges

Role of measurement uncertainties

  • Uncertainties and variabilities
  • Interpretation of environmental monitoring results
  • Statistics limitations
  • Surveys in populations
slide-18
SLIDE 18
  • MODARIA. WG 5 – Routine Discharges

Correlations

slide-19
SLIDE 19
  • 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

slide-20
SLIDE 20
  • 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
slide-21
SLIDE 21
  • 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

slide-22
SLIDE 22
  • MODARIA. WG 5 – Routine Discharges

The Forge

slide-23
SLIDE 23

Thank you!

  • MODARIA. WG 5 – Uncertainty and variability analysis for assessments of radiological

impacts arising from routine discharges of radionuclides