numerical simulations for radioactive waste disposal nsrawd ifa-cea meeting, bucharest-magurele,...

Numerical Simulations for Radioactive Waste Disposal

NSRAWD

IFA-CEA Meeting, Bucharest-Magurele, October 20, 2011

To develop numerical simulation for radioactive waste disposal, combining computational work with experimental activities in order to improve and validate flow and transport numerical models.

Objectives: •To improve and validate flow and transport numerical models and codes used in disposal safety assessment at Saligny•Develop new in-field test and collect experimental data for Alliances codes validations and for better understanding of site characteristics •Increase confidence in the numerical modelling used in radioactive waste disposal•To develop an integrated system for safety assessment of LIL waste disposal applied to Saligny site as an useful tool for further application in the site licence

Scope of the project


Task sharing

Modelling of unsaturated flow and transport using Alliances

Alliances

Modelling saturated flow and transport using Alliances

Alliances & Uranie

Modelling of unsaturated flow and transport using FEHM / Alliances

Saligny site data

Modelling unsaturated flow and transport using Alliances

Modelling flow and transport using FEHM

Saligny site data

Safety assessment using Goldsim

Saligny site data

Training

Benchmark

Training

Benchmark

Confidence

Confidence

Validation

Validation

Data

Surface response


Progress (1/5)

Stratification of soil layers

Input data directly extracted from the databaseLayer average

saturation[-]average pressure

[m]

theta_s (porosity)[-]

SILTY LOESS 0.2700 46.0 0.4141FOSSILIZED SILTY LOESS 0.4725 37.0 0.3852UPPER CLAYEY LOESS 0.3575 33.0 0.4097FOSSILIZED CLAYEY LOESS 0.5500 29.5 0.3944LOWER CLAYEY LOESS 0.3711 23.5 0.4132RED CLAY 0.7275 17.0 0.3935PREQUATERNARY CLAY 0.8400 7.27 0.3755

Suction curves used to extract Van Genuchten parameters for the saturation law

Layer alpha n m theta_rSILTY LOESS 2.3425 14.8846 0.0204 0.0968FOSSILIZED SILTY LOESS 0.0010 0.4700 3.3700 0.0272UPPER CLAYEY LOESS 0.2553 0.7594 0.6096 0.0727FOSSILIZED CLAYEY LOESS 0.0059 0.4867 1.5236 0.0017

LOWER CLAYEY LOESS 0.0004 0.3873 6.2282 0.0682RED CLAY 0.0296 0.7244 0.7204 0.0111PREQUATERNARY CLAY 0.0001 0.4300 2.8000 0.0092

Van Genuchten parameters

Selection of the suction curves was made in order to match optimally the average saturation and pressure for each layer

mnr

rlS

SS

1

1

1

Training in Alliance Platform, implementation and application in Saligny site modeling


Progress (2/5)

Inter-comparison of Alliances and FEHM predictions

Comparison with experimental data (validation)

- using same input parameters - Alliances underestimates the water content

- need to develop further modeling of test case using FEHM and Alliances


Alliances Case Study: Flow Field in Unsaturated Zone of the Saligny SiteA. Constantin, D. Diaconu, A. Genty, NUCLEAR 2011, May 28-30, 2011, Pitesti, Romania

Hydrogeology Modeling of the Unsaturated Zone of the Saligny Site A. Constantin, D. Diaconu, A. Genty, SIEN 2011, October 16-20, 2011, Bucharest, Romania

Progress (3/5)Saturated flow modeling in Alliances- pumping test - good agreement with measured data- tracer test – not consistent with experimental dataConclusion: Fractures play an important role in contaminant transport

Flow and transport parameters calibration of the Saligny aquifer (Romanian) using the alliances Platform A. Genty, D. Diaconu, C. Bucur, A. Constantin, MODELCARE2011, Leipzig, September 2011, Germany


Progress (4/5)

Modeling transient flow with FEHM- time-variable upper-boundary condition- meteorological data recorded during 2009 –

2010

Water content variation at different depths (FEHM predictions)


-1.0E-03

-5.0E-04

0.0E+00

5.0E-04

1.0E-03

1.5E-03

2.0E-03

2.5E-03

0 2000 4000 6000 8000 10000flu

x (k

g/s)

time (hours)

61.0

61.5

62.0

62.5

63.0

63.5

64.0

1.E-13 1.E-10 1.E-07 1.E-04 1.E-01

elev

ation

(mdM

N)

Iodine (mol/l)

222 days

central


Progress (5/5)

Tracer test objectives- get in-field data on chemical species migration- validate transport models for reactive transport

Status :- designed, planned and launched

- tracer: Iodine- concentration: 20mg/l- depths: 60cm- location: meteo station- sampling for Iodine baseline

- tracer transport simulations- planning of the next sampling moments

Iodine concentration profiles at different time after tracer release- FEHM simulation in transient conditions -

61.0

61.5

62.0

62.5

63.0

63.5

64.0

1.E-25 1.E-20 1.E-15 1.E-10 1.E-05 1.E+00

elev

ation

(mdM

N)

Iodine (mol/l

22 days

centrallateral 1mlateral 2m

61.0

61.5

62.0

62.5

63.0

63.5

64.0

1.E-18 1.E-15 1.E-12 1.E-09 1.E-06 1.E-03 1.E+00

elev

ation

(mdM

N)

iodine (mol/l)

119 days

central

lateral 1 m

lateral 2 m

Perspectives of collaboration

Under the project• Hydraulic modelling including fractures in the Saligny aquifer.• Transport modelling in the vadoze zone on the Saligny site and benchmarking.• Model transport using surface response build by Uranie module inside Alliances.

Beyond the project• Joint studies on the hydro-geological and hydro-chemical modelling of the

Saligny site.• Joint modelling of alternative subsurface radioactive waste disposals and

analysis of different scenarios.


Benefits

• Improve and validate flow and transport numerical models and codes used in disposal safety assessment at Saligny.

• Improve site characterisation and better understanding of transport processes.

•Increase confidence in the numerical modelling used in safety assessment of radioactive waste disposal.

•Improve and validate flow and transport numerical models used by Alliances platform based on experimental data.

•Promote a larger use of Alliances platform and transfer knowledge on radioactive waste modelling.

•Increase confidence in the numerical modelling used in radioactive waste disposal.


numerical simulations for radioactive waste disposal nsrawd ifa-cea meeting, bucharest-magurele,...

Documents