OECD/NEA WORKSHOP-TCOFF PROJECT

Hosted by JAEA/CLADS, Fukushima, Japanat FRC (Fukushima Research Conference)
10-12 July 2019

Materials Science for Severe Accident andFukushima Daiichi decommissioning
WORKSHOP 2019

Deadline for submission of abstracts:

15 May 2019

Deadline for Seminar registration:

31 May 2019

Final programme distribution:

20 June 20191

1- Background and Objectives
In the frame of the OECD/NEA TCOFF (THERMODYNAMIC CHARACTERISATION
OF FUEL DEBRIS AND FISSION PRODUCTS BASED ON SCENARIO ANALYSIS OFSEVERE ACCIDENT PROGRESSION AT FUKUSHIMA DAIICHI) project, a 2.5 days’
workshop devoted to the use of Materials Science for Severe Accident evaluation
will be held by CLADS at Fukushima, 10-12 July 2019.
The workshop is divided in 5 sessions.
1/ Integral and/or mechanistic severe accident codes
The first session is dedicated to the use of Materials Science and physical-chemistry
phenomena in integral and/or mechanistic severe accident codes such as MELCOR, ASTEC,MAAP, THALES-II, SOCRAT, SAMPSON… An overview of the modelling approach andarchitecture of these codes can be presented and focused on the coupling between physicalchemistry and thermal-hydraulic. Particular relevance is given to the coupling between
Thermal-hydraulic and thermodynamics in the Severe Accident codes: key data, methods(coupling or simplified model), sensitivity analysis. Communication can be also dedicated tosome SA-key-phenomena such as Fission products release and transport, corium concreteinteraction or corium spreading under water as example for the use of thermodynamic data.
It is possible at last to propose communication on modeling and evaluation of Fukushima
Daiichi 1F1, 1F2, 1F3 Severe Accidents.
2/ Experimental set ups and high temperature experiments
The second session is devoted to the experimental approach and Thermodynamic Data Base(TDB) construction in the field of Severe Accident Conditions. For the experimental data, it ispossible to present experimental set up at high temperature, experimental reliability anduncertainties. Communication can be also dedicated to Post-Test Analyses (PTA) methods andreliability for corium measurements. The use and the building of the thermodynamic databases can be presented with a focus on status of knowledge for the systems including corium(U,Zr,Fe,Ni,Cr,O…), Fission Products (I, Ce, Ba, Ru….) and water (H,O) at high temperature
representative of Severe Accident conditions.
3/ Thermodynamic (Calphad) modeling
The third session is focused on Thermodynamic modelling under Severe Accident conditions(high temperature, from liquid state until solid state, vaporization effect). Communication ondifferent corium materials and Fission Products including water with impurities (H3BO4,NaCl…), i.e. conditions close to Fukushima Daiichi conditions can be proposed. Communication
on current status of knowledge for the different possible solid state of corium for Fukushima2

Daiichi is also possible. Corium leaching and modeling is also a topic of this session. At last,communication on kinetics by thermodynamic approach is possible.
4/ Accident Tolerant Fuels
The fourth session is devoted to Accident Tolerant Fuel (ATF). After Fukushima events, newarea of research to manage Severe Accidents have been developed. Especially, ATF could beinnovative solution to Severe Accident Management. Communication on the status ofknowledge for the thermodynamic data of these systems coupled with the use in Severe
Accident codes can be proposed.
5/ Uncertainties and Reliability
The fifth session is focused on uncertainty, reliability and propagation of uncertainty in thefield of codes used for Severe Accident application: thermodynamic calculation, integral
codes. Communication on use of thermodynamic databases with Gibbs Minimizer andevaluation of their uncertainties is possible. Sensitivity studies can be also presented comingfrom integral or mechanistic codes for in or ex-vessel Severe Accident configuration.
A special poster session including the five topics above is planned during the TCOFF workshop.

32- Technical Content of the Workshop
Wednesday 10 July

Welcome

Introduction, keynote speech, updated information on Fukushima-Daiichi
decommissioningSession 1: Severe accidents codes and Materials Sciences- Fukushima-Daiichi
Accident Progression Analyses

Session 2: Experimental thermodynamic data, construction of thermodynamic databases



Reception: (Details, including fees, will be provided soon)

Thursday 11 July
Tour of the Fukushima Daiichi NPS (9:30-13:00, no fees, reservation needed)Session2(cont.):Experimental

thermodynamic

data,constructionofthermodynamic data-bases


Session 3: Thermodynamic modeling for SA conditions – Decommissioning-LeachingPoster session

Friday 12 July

Session 4: Accident Tolerant Fuel modeling for SA conditions



Session 5: Improvement for the use of Thermodynamic in SA codesPanel discussion and conclusion

4

3-Participation
Participation in the Seminar is mainly intended for organizations from countries signatories ofthe TCOFF project. TCOFF Project participating organizations are encouraged to distribute thisannouncement to other organizations from their countries.
The TCFOFF Project Management Board has also approved the extension of the invitation toother countries involved in NEA activities. Participation will be approved by the Organizing
Committee.
The workshop is free of charge except for the lunches and beverages.
TCOFF Project participants are encouraged to submit presentations for the various sessions.
Authors are requested to send to the secretariat a one-page abstract (200 words) of their
proposed presentation before.
Grants can be propose for students.
More detailed information are provided through the following address
http://www.oecd-nea.org/confdb/confdb/conf?id=357

4- Organizing Committee (OC)An Organizing Committee has been nominated to prepare the technical content of theseminar on the basis of abstracts received, organize the seminar and prepare the summary
record. The OC members are:
Dr Masaki Kurata (JAEA) kurata.masaki@jaea.go.jp
Dr Pascal Piluso (CEA) pascal.piluso@cea.fr
Prof. Sevostian Bechta (KTH): bechta@safety.sci.kth.se
Dr Sergii Nichenko (PSI): sergii.nichenko@psi.ch
Prof. Yoshinao Kobayashi (TITECH) : kobayashi.y.at@m.titech.ac.jp
Dr Stéphane Gossé (CEA): stephane.gosse@cea.fr5

5- Registration, Hotel, Meal, Transportation, Reception, Technicaltour, Others

Registration: Registration fee of workshop is free. Participants are requested to pay hotel,meal, transportation and reception fees, respectively, for themselves.
Hotels: For the night of 9th of July, your stay in hotels in Iwaki is recommended (You have
many choices at ~JPY10,000/night, inc. breakfast). For the night of 10th and 11th of July,
70 single rooms were tentatively reserved in J-village (~JPY8,000/night, inc. breakfast). The
participants are requested to pay for themselves at the desk or preliminary. If you willcancel your participation, please inform contact persons as soon as possible. If not, you
are requested to pay cancel fee later.
Meals: As for the dinner of 9th of July, you have many choices in Iwaki (please ask to yourhotels). As for the dinner of 10th of July, your participation to reception is welcome. If not,you can eat at a restaurant in J-village. As for the dinner of 11th of July, the restaurant(buffet) in J-village is available. As for lunch during the workshop, Japanese style lunch box
will be prepared and you will be requested to pay preliminary at registration (by cash,~JPY1,000/lunch).
Transportation: From Tokyo, the use of JR-Joban line is recommended. It takes ~2h15minfrom Tokyo to Iwaki.
(Reception) In 10th of July, reception will be held in «Joban Hawaiian Center». The fee willbe ~JPY8,000 including Hawaiian dance show. Your participation will be preliminary asked
from a local committee and you will be requested to pay at registration.
(Technical tour) In 11th of July (before lunch), a technical bus tour to Fukushima-Daiichi
Nuclear Power Plant is scheduled. 30 seats are available. If you are interested in the tour,
you are preliminary requested to contact the local committee. The tour is free.
(Others) For your convenient stay in Japan, to bring a small amount of cash
(10,000~20,000JPY) is recommended. You can rent a wifi-terminal at the airport(~JPY15,000/week). It is very convenient for your stay in Japan.

If you need any assistance, please, feel free to ask contact persons

6- Contact persons
Dr Davide Costa (NEA): davide.costa@oecd-nea.org (Tel.: +33 (0)1 45 24 10 89)
Dr Masaki Kurata (JAEA, local coordinator): kurata.masaki@jaea.go.jp

67- Venue J-Village, Fukushima, Japan7