Spent Fuel and Waste Science and Technology

Surface Complexation and Ion Exchange Database Development Phase 1: Clay Minerals

M. ZavarinLawrence Livermore National Laboratory

SFWST Annual Working Group MeetingLas Vegas, Nevada

May 22-24, 2018

LLNL-PRES-751626This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. Lawrence Livermore National Security, LLC

Spent Fuel and Waste Science and Technology

TitleMay 23, 2018

Overview of Activity

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We need to develop self-consistent surface complexation/ion exchange models, in concert with thermodynamic models, for nuclear waste repository performance assessment

This issue was expressly identified in the recent NEA Sorption project reports

Some progress on this issue has been made only recently in various international nuclear waste repository programs

The best path forward for developing such databases remains an open question, particularly in cases where generic repositories are being investigated resulting in a need to predict radionuclide sorption behavior over a very broad range of solution and mineralogic conditions.

Spent Fuel and Waste Science and Technology

TitleMay 23, 2018

Effect on Repository Performance or Safety Case Confidence

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A simple Kd approach is likely to be insufficient from the standpoint of Performance Assessment– Relies on conservative

assumptions A surface complexation/ion

exchange modeling approach is more defensible (state of the art) and allows for evaluation of alternative scenarios and hydrobiogeochemicaluncertainties. – However, an SC/IE approach is

likely too cumbersome for PA modeling

– The “smart-Kd” approach has been suggested (pursued in Germany)

From Stockman et al. http://dx.doi.org/10.1016/j.chemosphere.2017.08.115

Spent Fuel and Waste Science and Technology

TitleMay 23, 2018

Integration with GDSA/PA and/or the Safety Case

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Identify range of parameter space in GDSA/PA and/or Safety Case

Use combined TDB and SC/IE database to extract partitioning info across range of parameter space

Produce Smart Kd tables

Apply to GDSA/PA and/or Safety Case to account for parameter and condition uncertainty

Spent Fuel and Waste Science and Technology

TitleMay 23, 2018

Example: U(VI) on QuartzSCM

Mineral Area

Site

pK 1 pK 2 logK Chemical Equation Literature DDL Quartz 0.2 4.81 5.62 -5.72 »Si-(OH)2 + UO2<2+> = »Si-O2-UO2 + 2 H<1+> AZBN00a

DDL Quartz 0.2 4.81 5.62 -5.51 »Si-(OH)2 + UO2<2+> = »Si-O2-UO2 + 2 H<1+> AZZBN01 DDL Quartz 10 10 -1.6 7.6 -7.259 »X-OH + UO2<2+> + H2O = »X-O-UO2(OH) + 2 H<1+> JHLCH99 DDL Quartz 10 10 -1.6 7.6 9.529 »X-OH + UO2<2+> + CO3<2-> = »X-O-UO2CO3<1-> + H<1+> JHLCH99 DDL Quartz 10 10 -1.6 7.6 -1.978 »X-OH + UO2<2+> = »X-O-UO2<1+> + H<1+> JHLCH99 DDL Quartz 0.05 -7.2 -16.75 »SiOH + 3 UO2<2+> + 5 H2O = »SiO-(UO2)3(OH)5 + 6 H<1+> NB10 DDL Quartz 0.05 -7.2 0.3 »SiOH + UO2<2+> = »SiO-UO2<1+> + H<1+> NB10 DDL Quartz 0.05 -7.2 -5.65 »SiOH + UO2<2+> + H2O = »SiO-UO2(OH) + 2 H<1+> NB10 DDL Quartz 0.31 2.3 -1.24 7.06 -0.3 »Si-OH + UO2<2+> = »Si-O-UO2<1+> + H<1+> PJTP01 DDL Quartz 0.31 2.3 -1.24 7.06 -18.7 »Si-OH + UO2<2+> + 3 H2O = »Si-O-UO2(OH)3<2->+ 4 H<1+> PJTP01 DDL Quartz 0.03 2.3 7.2 0.3 »Si-OH + UO2<2+> = »Si-O-UO2<1+> + H<1+> PTBP98 DDL Quartz 0.03 2.3 7.2 -16.75 »Si-OH + 3 UO2<2+> + 5 H2O = »Si-O-(UO2)3(OH)5 + 6 H<1+> PTBP98 DDL Quartz 0.03 2.3 7.2 -5.65 »Si-OH + UO2<2+> + H2O = »Si-O-UO2(OH) + 2 H<1+> PTBP98 DDL Quartz 0.1 2.31 7.2 -8.45 »Si-OH + UO2<2+> + 2 H2O = »Si-O-UO2(OH)2<1-> + 3 H<1+> VT98 NE Quartz 0.33 0 -4.95 »Si(w)-OH + UO2<2+> + H2O = »Si(w)-O-UO2(OH) + 2 H<1+> DK01 NE Quartz 0.33 0 1.06 »Si(s)-OH + UO2<2+> = »Si(s)-O-UO2<1+> + H<1+> DK01 NE Quartz 0.33 0 -3.19 »Si(s)-OH + UO2<2+> + H2O = »Si(s)-O-UO2(OH) + 2 H<1+> DK01 NE Quartz 0.33 0 -2.56 »Si(s)-OH + UO2<2+> + H2O = »Si(s)-O-UO2(OH) + 2 H<1+> DK01 NE Quartz 0.33 0 -4.98 »Si(w)-OH + UO2<2+> + H2O = »Si(w)-O-UO2(OH) + 2 H<1+> DK01 NE Quartz 0.33 0 1.2 »Si(s)-OH + UO2<2+> = »Si(s)-O-UO2<1+> + H<1+> DK01 NE Quartz 0.33 0 -4.64 »Si(w)-OH + UO2<2+> + H2O = »Si(w)-O-UO2(OH) + 2 H<1+> DK01 NE Quartz 0.33 0 -0.03 »Si(w)-OH + UO2<2+> = »Si(w)-O-UO2<1+> + H<1+> DK01 NE Quartz 0.33 0 -5.28 »Si(w)-OH + UO2<2+> + H2O = »Si(w)-O-UO2(OH) + 2 H<1+> DK01 NE Quartz 0.33 0 10.183 »Si(w)-OH + UO2<2+> + CO3<2-> = »Si(w)-O-UO2CO3<1-> + H<1+> DK01 NE Quartz 0.33 0 -3.28 »Si(s)-OH + UO2<2+> + H2O = »Si(s)-O-UO2(OH) + 2 H<1+> DK01 NE Quartz 0.33 0 -4.73 »Si-OH + UO2<2+> = »Si-O-UO2(OH) + 2 H<1+> KCKD96 NE Quartz 0.33 0 -5.32 »Si(w)-OH + UO2<2+> + H2O = »Si(w)-O-UO2(OH) + 2 H<1+> KCKD96 NE Quartz 0.33 0 -2.65 »Si(s)-OH + UO2<2+> + H2O = »Si(s)-O-UO2(OH) + 2 H<1+> KCKD96 NE Quartz 0.33 0 -2.56 »Si(s)-O(0.5)H + UO2<2+> + H2O = »Si(s)-O(0.5)-UO2(OH) + 2 H<1+> K02b NE Quartz 0.33 0 -7.78 »Si(w)-O(0.5)H + UO2<2+> + CO2 + H2O = »Si(w)-O(0.5)-UO2CO3(OH)<2-> + 3 H<1+> K02b NE Quartz 0.33 0 -6.56 »Si(w)-O(0.5)H + UO2<2+> + H2O = »Si(w)-O(0.5)-UO2(OH) + 2 H<1+> K02b NE Quartz 0.33 0 -5.57 »Si(s)-O(0.5)H + UO2<2+> + H2O = »Si(s)-O(0.5)-UO2(OH) + 2 H<1+> K02b NE Quartz 0.33 0 -6.5 »Si(w)-O(0.5)H + UO2<2+> + CO2 + H2O = »Si(w)-O(0.5)-UO2CO3(OH)<2-> + 3 H<1+> K02b NE Quartz 0.33 0 -5.28 »Si(w)-O(0.5)H + UO2<2+> + H2O = »Si(w)-O(0.5)-UO2(OH) + 2 H<1+> K02b TL Quartz 0.32 0.00184 8.4 1.98 »Si(s)-OH + UO2<2+> = »Si(s)-O-UO2<1+> + H<1+> FDZ06 TL Quartz 0.32 0.00184 8.4 -1.88 »Si(s)-OH + UO2<2+> + H2O = »Si(s)-O-UO2(OH) + H<1+> FDZ06

RES3t output of SC data for one metal-mineral pair

Spent Fuel and Waste Science and Technology

TitleMay 23, 2018

Example: U(VI) on quartz

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AZBN00a

AZBN01

DK01DK01

DK01

DK01

DK01

FDZ06

JHLCH99

JHLCH99

KCKD96

PJTP01

PTBP98

PTBP98

PJTP01DK01

DK01

RES3t referenced data for one metal-mineral pair

Spent Fuel and Waste Science and Technology

TitleMay 23, 2018

Example: U(VI) on quartz

Comparison of data and simultaneous model fits to ALL U(VI)-quartz data

Significant scatter at low sorbed/aqueous ratios is a result of inherent uncertainties associated with samples with little to no U(VI) sorption

>SiO- logK = -3.85 ± 0.04>SiOUO2OH logK = -4.56 ± 0.04

(-2.56 to -5.32 in RES3t database)>SiOUO2(OH)2

- logK = -10.71 ± 0.04>SiOUO2CO3

- logK = 2.02 ± 0.04

Non-electrostatic model, 2.3 sites/nm2, one site type

Spent Fuel and Waste Science and Technology

TitleMay 23, 2018

Relationship to R&D Priority Ratings

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Task #

Task Name/

(and Work Package

number -- if needed or helpful for

more specificity)

Brief Task Description

includingRelevance (and/or input) to PA/GDSA

(nPA = not direct input to PA)

Personnel/Lab

Code(if

applicable)

Importance to Safety Case

(ISC)

(H, M, or L --see ISC table definitions)

(Identify applicable

Safety Case element from the provided

figure)

Current "State of the Art" Level

(SAL = 1, 2, 3, 4, or 5 --see SAL table definitions)

(Give brief update to applicable state-of-the-

art "discussion(s)" shown in UFD Roadmap

App. A, i.e., those discussion(s) for the

highest scoring related FEPs)

Short-term (1 yr) R&D Priority Scores

& Brief FY19 Work Scope Proposal

(Priority Score = H, M, or L, based on

combined ISC and SAL -- see PS table

definitions)

(Also give Roadmap Score for related FEP)

Related UFD Roadmap

Issue(s)/FEP(s), and associated UFD Roadmap priority scores*

(Find highest scoring related

FEP in App. B of UFD Roadmap)

Other Notes/Comments

(e.g., type of linkage to PA-GDSA; inputs

required and/or linkages to other

models and experiments)

17

Thermodynamic and sorption

database(s)

• Probably nPA•Thermodynamic, surface complexation/ion-exchange databases

M. Zavarin, C. Duffin,

T. WoleryLLNL

N/A

ISC = Medium SC

elements 3.3, 4.2 and 4.3

SAL=5 or 3 Data and methods are known. However, an adequate representation in database for is not yet available and needs to be developed. Implementation in GDSA not developed.

Database improvements (TDB) and database development begins. Priority score: M

• Thermodynamic, surface complexation/ion-exchange databases, used as input to process models• Surface complexation unlikely to be represented in PA

Spent Fuel and Waste Science and Technology

TitleMay 23, 2018

Current State of the Art and Past Accomplishments

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Current State of the Art:– Abundant (though incomplete) RN-mineral data available in the literature with associated

modeled reaction constants using a variety of SC and IE formulations (Vanselow, Gapon, Non-electrostatic, Diffuse Layer, MuSIC, etc.)

– Various mineral-specific compilations of SC and IE data exist in the literature (e.g. Dzombakand Morel, Karamalidis and Dzomback, etc.)

– Comprehensive SC databases are available in various levels of development (RES3t, PSI, etc.)

– Kd compilations have been developed (e.g. YMP, JAEA)

Past Accomplishments:– Approach has been demonstrated with

U(VI)-quartz using compiled primary data and

refit to non-electrostatic models.

– Codes and approach identified to test

various geochemical models

Spent Fuel and Waste Science and Technology

TitleMay 23, 2018

Integration with International

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Development efforts are aligned with RES3t approaches and database developments (HZDR, Germany)

Coordinated with NEA-TDB and SFWST thermodynamic database development efforts

Spent Fuel and Waste Science and Technology

TitleMay 23, 2018

Future R&D & Integration Timeframe

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FY18-19 effort will focus on demonstrating database development for clay minerals

Based on reference compilations contained in RES3t and focused on montmorillonite

Developed for key radionuclides (Cs, Sr, U, Np, Pu)

Demonstrate “smart Kd” approach and application in GDSA

From Stockman et al. http://dx.doi.org/10.1016/j.chemosphere.2017.08.115

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Questions?

12

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Back-Up Slides

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