Euratom 7 th Framework Programme Collaborative Project Fast / Instant Release of Safety Relevant Radionuclides from Spent Nuclear Fuel

Euratom 7

Framework Programme

Collaborative Project “Fast / Instant Release of Safety

Relevant Radionuclides from Spent Nuclear Fuel”

FIRST-Nuclides

25-26th _{October 2012}

Bernhard Kienzler, KIT-INE, Karlsruhe, D

Alba Valls, AMPHOS21, Barcelona, E

Volker Metz, KIT-INE, Karlsruhe, D

Acknowledgement: The research leading to these results has received funding from the European Atomic Energy Community's Seventh Framework Programme (FP7/2007-2011)

EU Call:

Research activities in support of implementation of

geological disposal (

Fission-2011-1.1.1)

Type:

Small/medium scale Collaborative Project

Financial:

4,741,261 € total costs

2,494,513 € EU contribution

Duration:

01. Jan. 2012 – 31.Dec. 2014 (3 years)

Definition of instant / fast release

Project related definition or PA related definition

Definitions:



PA term:

„instant“ release



Experimental / lab related:

fast release (for a specific fuel sample)

controlled by: sample

preparation, fragment size,

presence of cladding, duration of experiments, ...

RN release by matrix corrosion

controlled by radiolysis,

hydrogen, Cl-....



initial (fast) release of RN

controlled by chemistry,

spatial distribution,

burn-up, lin. power,

(reactor operation)

Spent fuel

Cladding: C

Gap region: C, I, Cs, Se, Tc Enriched rim: Pu Spent fuel     _                     _   _          fuel grains U, Pu, Ln, Sr fission gas bubbles Kr, Xe, I Grain boundaries C, I, Cs, Se, Tc Rim enriched withPu -particles metallic precipitates Mo, Ru, Pd, Tc, Rh Ag, Cd, In, Sb, Sb oxide precipitates Rb, Cs, Ba, Zr, Nb Mo, Tc

Rationale of FIRST-Nuclides



Previous EU projects (MICADO, NF-Pro, SFS, ...)

– Improvement in understanding.

o high burn-up UO₂, linear power, temperature, ramping, ...

– Relationship FGR and release of non-gaseous FPs

o gases, 135_Cs, 129_I, 14_{C compounds,} 79_Se, 99_{Tc and} 126_Sn.

– Grain boundary effects.

– Chemical speciation of relevant elements.



Vision Report and SRA of the IGD-TP

– Key topic: Waste forms behaviour, in particular high burn-up

spent UO

fuels.



Recommendations by the End Users

(kick off meeting)

– Definition of instant – rapid – fast release and delineation to

long-term RN release processes.

– Up-scaling from lab sample to rod/assembly.

– Effect of geochemical conditions.

1. Partners / Beneficiaries

The Consortium (1)

Subatech

Hungarian Academy of Sciences, Centre for

Energy Research

2. Associated Groups (AG)

Groups participating at their own costs with specific RTD contributions or particular information exchange functions, or mobility measures (for European AGs only)

Roles and Tasks within CP FIRST-Nuclides

:

• Review the work program

• Review the scientific-technical progress and contributions to the proceedings • Assess the project status and provide recommendations for the work program • Review the plan for dissemination of the final results.

3. End-user group:

Representatives:

Project Events/Milestones



Kick-off:

8-9 Feb. 2012



Topical Sessions



1

Annual Workshop: 9-11 Oct. 2012

•

Scientific &Technical Output:

20 S&T

•

To be published (KIT Scientific Report)

•

Review by the EUG

Reflection of end-user interests on the S&T contributions:

 ... reflects fully the end user interests as defined in the SRA of the IGD-TP.

 ... is a preparation work required to reflect the end user interests

 ... presents methodological work required to reflect the end user interests

 ... is relevant within the technical scope of the project.

 ... is relevant for specific reporting, dissemination and communication purposes

Work Programme:



6 Workpackages

WP 1: Samples and tools

Selection, characterization and preparation of and set-up of tools

for handling and transportation of the highly radioactive material

WP leader: Volker Metz (KIT)

PWR BWR THTR / VVER

Discharge 1989 -2008 2005 – 2008

Pellet Enrichment 3.80 – 4.94 % 3.30 -4.25 % 2.4 -16.8%

Irradiation Burn-up 50.4 – 70.2 GWd/t 48.3 – 57.5 GWd/tU

Cycles 2 - 14 5 – 7

lin. Power average 186 -330 W/cm 160 W/cm 130 – 228 W/cm

WP 2:

Gas release and

rim and grain boundary diffusion



Experimental determination of fission gas release

WP leader: Detlef Wegen (JRC-ITU)



Experimental investigation of rim / grain boundary diffusion

Puncturing device Fuel Rod Ventilation Analysis Ne Vd Ve1 Ve2 Vd = Drilling Chamber Ve1 = Expansion Chamber 1 Ve2 = Expansion Chamber 2 ST1 = Storage Tank 1

ST2 = Storage Tank 2

ST1 ST2

Drill

WP 3: Dissolution based release



Dissolution based radionuclide release and to the extent

possible the chemical speciation of the relevant isotopes.

Partners:

KIT-INE, JRC-ITU / CTM, PSI, Studsvik,

EK (MTA), SCK•CEN

WP leader: Karel Lemmens (SCK·CEN)

Agreement on experimental details to cover the whole range of conditions:

 Samples/sample preparation (powder – pellets)

 Conditions (oxic – anaerobic)

borate Na+ _I- _Cl- _HCO 3- Ca2+ Mg2+ SO42- pH PSI 28 >0.13 0.13 1.1 - - - 8.5 KIT - 19 - 19 1 - - - 7.4 ITU/CTM - 19 - 19 1 - - - 7.4 SCKCEN - 19 - 19 1 - - - 7.4 Studsvik - 2.26 - 1.4 1.8 0.464 0.19 0.1 8.1-8.2 Conditions PSI anoxic/oxic KIT anoxic ITU/CTM oxic SCKCEN oxic Studsvik oxic  Atmospheric conditions

 Leach media (simple to complex or buffer solution)

PSI

Studvik

INE: pellet / fragm.

CTM: powder

 Sample preparations: powder, fragments,

pellets +/- cladding

ITU: fragments

WP4: Modelling

 Quantify the fast/instant release fraction of fission products.

– FP migration along the grain boundaries and fractures,

– effects of defects in the cladding on the fast release.  Up-scaling from fragments/pellets to fuel assemblies.

Aims of the conceptual and numerical modelling

WP leader: Joan de Pablo (CTM/UPC)

 Modeling the chemical state of relevant elements.

Modelling Approach:

The Reference Pellet & sub-µm scale model

From Willford (1984)

The Idealised Reference Pellet:

• 13.5 mm high and 8.19 mm in diameter

• Mean crack aperture of 20 µm

• Easy to implement aperture(r, h)

Additional 1D calculations wrt the sub-μm cracks

• 1 mm reference distance



Knowledge management and documentation of the

State-of-the-Art with regular up-dating.



Stepwise build-up of scientific-technical reporting



Dissemination and Communication,



Training

WP5:

Knowledge, reporting and training:

WP leader: Alba Valls (AMPHOS21)

Please see the project webpage

www.firstnuclides.eu

DELI VERABLE (D-N°:5.1) State of the art report

Author(s): KI T/AM PHOS21

Reporting period: e.g. 01/01/2012 – 30/06/2013 Date of issue of this report: 30/06/2012

Start date of project: 01/01/2012 Duration : 36 Months

Project co-funded by the European Commission under the Seventh Euratom Framework Programme for Nuclear Research & Training Activities (2007-2011)

Dissemination Level

PU Public X

RE Restricted to a group specified by the partners of the [FIRST-Nuclides]

project

CO Confidential, only for partners of the [FIRST-Nuclides] project

FI RST-Nuclides

(Contract Number:295722)

Available in the Project website Uploaded in the official web

0. INTRODUCTION

1. DESCRIPTION OF THE FUEL

UO₂ PELLET

ENRICHMENT AND POSSIBLE BURN-UP FUEL RODS

FUEL ELEMENTS / ASSEMBLIES

2. IRRADIATION INDUCED PROCESSES IN UO₂

TEMPERATURE OF THE FUEL IN A REACTOR

3. OPTIMIZATION OF NUCLEAR FUEL (UO₂) 4. MODELING TOOLS FOR FUEL PERFORMANCE 5. DISPOSAL OF SPENT NUCLEAR FUEL

CANISTER CONCEPTS

WATER CONTACT TO THE FUEL IN THE CASKS WATER ACCESS TO THE SPENT FUEL

6. PREVIOUS INVESTIGATIONS ON FAST/INSTANT RELEASE 7. SELECTION OF MATERIALS WITHIN FIRST-NUCLIDES

8. OBJECTIVES OF FIRST-NUCLIDES IN THE CONTEXT OF PREVIOUS INVESTIGATIONS 9. REFERENCES APPENDIX I: MANUFACTURERS

D5.1

.

T

ab

le

of

co

nte

nts

gap and grain boundary release:

• 80 PWR fuel experiments

• 20 BWR fuel experiments



Thank you

WP6:

Coordination

and management