Deep disposal of eurobitum bituminised waste: Scoping calculations of nitrate release

Eef Weetjens; Xavier Sillen; Elie Valcke

doi:10.1557/proc-932-41.1

Deep disposal of eurobitum bituminised waste: Scoping calculations of nitrate release

Eef Weetjens, Xavier Sillen, Elie Valcke

Research output › peer-review

Abstract

The Eurobitum bituminised waste produced by the former EUROCHEMIC reprocessing plant in Mol-Dessel (Belgium) contains a lot of salts, mainly NaNO₃. This NaNO₃ may possibly affect significantly the evolution of a radwaste repository through redox and ion exchange reactions with Boom Clay, which in Belgium is studied as a reference host formation. Yet, the leaching behaviour of NaNO₃ from the Eurobiturn and its migration in the Boom Clay is rather unclear. Therefore, some scoping numerical calculations have been performed. In a first phase, we calculated the water flux towards the disposal gallery to assess the timescale of the saturation process of the disposal galleries. In a second phase, the leaching rate of NaNO₃ out of the drums is compared with its diffusive removal through the Boom Clay. The water flux to the gallery was calculated at approximately 100 ml/day per metre gallery, based on the natural pressure gradient observed around the HADES Underground Research Laboratory. Different approaches were elaborated to find a NaNO₃ source term for the diffusion calculations. For various ways of characterising the nitrate release, the numerical calculations generally show that the NaNO₃ concentrations in the first decimetres of Boom Clay will not be much higher than 1 M. Moreover, a sensitivity analysis showed that if the nitrate is released from the bituminised waste product within 10 000 years, the Boom Clay controls the concentration profiles; if the release is slower, the source term has a more pronounced effect on the near field concentrations.

Original language	English
Title of host publication	29th International Symposium on the Scientific Basis for Nuclear Waste Management XXIX
Place of Publication	Warrendale, United States
Publisher	Materials Research Society
Pages	735-742
Number of pages	8
ISBN (Print)	1558998896, 9781558998896
DOIs	https://doi.org/10.1557/proc-932-41.1
State	Published - 2006
Event	2005 - MRS : 29th International Symposium on the Scientific Basis for Nuclear Waste Management - Gent Duration: 12 Sep 2005 → 16 Sep 2005

Publication series

Name	Materials Research Society Symposium Proceedings
Volume	932
ISSN (Print)	0272-9172

Conference

Conference	2005 - MRS
Abbreviated title	MRS2005
Country/Territory	Belgium
City	Gent
Period	2005-09-12 → 2005-09-16

ASJC Scopus subject areas

General Materials Science
Condensed Matter Physics
Mechanics of Materials
Mechanical Engineering

Access to Document

10.1557/proc-932-41.1License: Unspecified

Cite this

@inproceedings{77ee3a3f70c54fd4928301cc8b83da7e,

title = "Deep disposal of eurobitum bituminised waste: Scoping calculations of nitrate release",

abstract = "The Eurobitum bituminised waste produced by the former EUROCHEMIC reprocessing plant in Mol-Dessel (Belgium) contains a lot of salts, mainly NaNO3. This NaNO3 may possibly affect significantly the evolution of a radwaste repository through redox and ion exchange reactions with Boom Clay, which in Belgium is studied as a reference host formation. Yet, the leaching behaviour of NaNO3 from the Eurobiturn and its migration in the Boom Clay is rather unclear. Therefore, some scoping numerical calculations have been performed. In a first phase, we calculated the water flux towards the disposal gallery to assess the timescale of the saturation process of the disposal galleries. In a second phase, the leaching rate of NaNO3 out of the drums is compared with its diffusive removal through the Boom Clay. The water flux to the gallery was calculated at approximately 100 ml/day per metre gallery, based on the natural pressure gradient observed around the HADES Underground Research Laboratory. Different approaches were elaborated to find a NaNO3 source term for the diffusion calculations. For various ways of characterising the nitrate release, the numerical calculations generally show that the NaNO3 concentrations in the first decimetres of Boom Clay will not be much higher than 1 M. Moreover, a sensitivity analysis showed that if the nitrate is released from the bituminised waste product within 10 000 years, the Boom Clay controls the concentration profiles; if the release is slower, the source term has a more pronounced effect on the near field concentrations.",

keywords = "Bitumens, Nitrate, Simulation, Flow models, Radioactive waste disposal, Boom Clay, Leaching, Diffusion",

author = "Eef Weetjens and Xavier Sillen and Elie Valcke",

note = "Score = 1; 2005 - MRS : 29th International Symposium on the Scientific Basis for Nuclear Waste Management, MRS2005 ; Conference date: 12-09-2005 Through 16-09-2005",

year = "2006",

doi = "10.1557/proc-932-41.1",

language = "English",

isbn = "1558998896",

series = "Materials Research Society Symposium Proceedings",

publisher = "Materials Research Society",

pages = "735--742",

booktitle = "29th International Symposium on the Scientific Basis for Nuclear Waste Management XXIX",

address = "United States",

}

Weetjens, E, Sillen, X & Valcke, E 2006, Deep disposal of eurobitum bituminised waste: Scoping calculations of nitrate release. in 29th International Symposium on the Scientific Basis for Nuclear Waste Management XXIX. Materials Research Society Symposium Proceedings, vol. 932, Materials Research Society, Warrendale, United States, pp. 735-742, 2005 - MRS , Gent, Belgium, 2005-09-12. https://doi.org/10.1557/proc-932-41.1

Deep disposal of eurobitum bituminised waste: Scoping calculations of nitrate release. / Weetjens, Eef; Sillen, Xavier; Valcke, Elie.
29th International Symposium on the Scientific Basis for Nuclear Waste Management XXIX. Warrendale, United States: Materials Research Society, 2006. p. 735-742 (Materials Research Society Symposium Proceedings; Vol. 932).

Research output › peer-review

TY - GEN

T1 - Deep disposal of eurobitum bituminised waste

T2 - 2005 - MRS

AU - Weetjens, Eef

AU - Sillen, Xavier

AU - Valcke, Elie

N1 - Score = 1

PY - 2006

Y1 - 2006

N2 - The Eurobitum bituminised waste produced by the former EUROCHEMIC reprocessing plant in Mol-Dessel (Belgium) contains a lot of salts, mainly NaNO3. This NaNO3 may possibly affect significantly the evolution of a radwaste repository through redox and ion exchange reactions with Boom Clay, which in Belgium is studied as a reference host formation. Yet, the leaching behaviour of NaNO3 from the Eurobiturn and its migration in the Boom Clay is rather unclear. Therefore, some scoping numerical calculations have been performed. In a first phase, we calculated the water flux towards the disposal gallery to assess the timescale of the saturation process of the disposal galleries. In a second phase, the leaching rate of NaNO3 out of the drums is compared with its diffusive removal through the Boom Clay. The water flux to the gallery was calculated at approximately 100 ml/day per metre gallery, based on the natural pressure gradient observed around the HADES Underground Research Laboratory. Different approaches were elaborated to find a NaNO3 source term for the diffusion calculations. For various ways of characterising the nitrate release, the numerical calculations generally show that the NaNO3 concentrations in the first decimetres of Boom Clay will not be much higher than 1 M. Moreover, a sensitivity analysis showed that if the nitrate is released from the bituminised waste product within 10 000 years, the Boom Clay controls the concentration profiles; if the release is slower, the source term has a more pronounced effect on the near field concentrations.

AB - The Eurobitum bituminised waste produced by the former EUROCHEMIC reprocessing plant in Mol-Dessel (Belgium) contains a lot of salts, mainly NaNO3. This NaNO3 may possibly affect significantly the evolution of a radwaste repository through redox and ion exchange reactions with Boom Clay, which in Belgium is studied as a reference host formation. Yet, the leaching behaviour of NaNO3 from the Eurobiturn and its migration in the Boom Clay is rather unclear. Therefore, some scoping numerical calculations have been performed. In a first phase, we calculated the water flux towards the disposal gallery to assess the timescale of the saturation process of the disposal galleries. In a second phase, the leaching rate of NaNO3 out of the drums is compared with its diffusive removal through the Boom Clay. The water flux to the gallery was calculated at approximately 100 ml/day per metre gallery, based on the natural pressure gradient observed around the HADES Underground Research Laboratory. Different approaches were elaborated to find a NaNO3 source term for the diffusion calculations. For various ways of characterising the nitrate release, the numerical calculations generally show that the NaNO3 concentrations in the first decimetres of Boom Clay will not be much higher than 1 M. Moreover, a sensitivity analysis showed that if the nitrate is released from the bituminised waste product within 10 000 years, the Boom Clay controls the concentration profiles; if the release is slower, the source term has a more pronounced effect on the near field concentrations.

KW - Bitumens

KW - Nitrate

KW - Simulation

KW - Flow models

KW - Radioactive waste disposal

KW - Boom Clay

KW - Leaching

KW - Diffusion

UR - http://ecm.sckcen.be/OTCS/llisapi.dll/open/ezp_31294

U2 - 10.1557/proc-932-41.1

DO - 10.1557/proc-932-41.1

M3 - In-proceedings paper

SN - 1558998896

SN - 9781558998896

T3 - Materials Research Society Symposium Proceedings

SP - 735

EP - 742

BT - 29th International Symposium on the Scientific Basis for Nuclear Waste Management XXIX

PB - Materials Research Society

CY - Warrendale, United States

Y2 - 12 September 2005 through 16 September 2005

ER -