Anna Ferrari MAXSIMA Meeting, 27 November 2013 1FLUKA Collaboration Meeting, 16.12.2014 Anna Ferrari

HZDR FLUKA activities in support of the MYRRHA Project

Short summary with a focus on activation problems Anna Ferrari, Stefan Müller, Jörg Konheiser

Helmholtz-Zentrum Dresden-Rossendorf

Anna Ferrari MAXSIMA Meeting, 27 November 2013 2FLUKA Collaboration Meeting, 16.12.2014 Anna Ferrari

Framework of this work: CDT-FASTEF + MAXSIMA EU FP7 projects

Goal: design a FAst Spectrum Transmutation Experimental Facility,

able to demonstrate efficient transmutation of high level waste

and associated technology

A look at the MYRRHA project

Heart of the MYRRHA facility at SCK·CEN in Mol

FASTEF + The MYRRHA construction could start in few (?) years

MAXSIMA design (planned to be operational in 2023)

Heart of the MYRRHA facility at SCK·CEN in Mol

FASTEF + The MYRRHA construction could start in few (?) years

MAXSIMA design (planned to be operational in 2023)

In MYRRHA (Multi-purpose hybrid research reactor for high-tech applications):

A LFR (Lead Fast Reactor) will operate both in critical and subcritical

mode.

Core power - 100 MW in critical mode

in the FASTEF design: - 94 MW in subcritical mode

An Accelerator Driven System with a 600 MeV proton beam

will be provided by a LINAC

A Compact Spallation Target will be provided, in LBE (Lead Bismuth Eutectic)

Anna Ferrari MAXSIMA Meeting, 27 November 2013 3FLUKA Collaboration Meeting, 16.12.2014 Anna Ferrari

600 MeV Proton beam-line

600 MeV Proton beam-line

Target window zone

Beam spot centre movement

Reactor

Spallation target

LINAC tunnel

Beam Dump

Casemate

The general shielding problem

up to 4 mA current

Analysis around the accelerator in:

A. Ferrari, J.-L. Biarrotte et al.,

SATIF-11 Conf. Proc.,

OECD/NEA Nuclear Science 7157,

13-27 (2013)

Anna Ferrari MAXSIMA Meeting, 27 November 2013 4FLUKA Collaboration Meeting, 16.12.2014 Anna Ferrari

Goal:

Neutronics, shielding and activation analysis in support of the safety

Key points:

- Detailed characterization of the shielding and of the activation problems

around the accelerator and around the core in both subcritical/critical

modes

- Definition of the shielding structures in the building areas not yet

optimized (ex. Cover, Vertical containment beyond the 90 magnet)

- Find activation problems that can have an impact on the design

Key points:

- Detailed characterization of the shielding and of the activation problems

around the accelerator and around the core in both subcritical/critical

modes

- Definition of the shielding structures in the building areas not yet

optimized (ex. Cover, Vertical containment beyond the 90 magnet)

- Find activation problems that can have an impact on the design

Method for the reactor analysis: combined use MCNPX and FLUKA.

- MCNPX is the official tool used to characterize the MYRRHA cores

FLUKA allows to evaluate the dose rates due to the activated materials

and with the real geometry

Method for the reactor analysis: combined use MCNPX and FLUKA.

- MCNPX is the official tool used to characterize the MYRRHA cores

FLUKA allows to evaluate the dose rates due to the activated materials

and with the real geometry

Anna Ferrari MAXSIMA Meeting, 27 November 2013 5FLUKA Collaboration Meeting, 16.12.2014 Anna Ferrari

The CDT model of the reactor containment system

(ANSALDO)

Hot LBE (350)

Argon

AISI 316L

Concrete

Hot LBE (350)

with SS content

Argon

with SS content

Nitrogen

Anna Ferrari MAXSIMA Meeting, 27 November 2013 6FLUKA Collaboration Meeting, 16.12.2014 Anna Ferrari

The new MAXSIMA model

Anna Ferrari MAXSIMA Meeting, 27 November 2013 7FLUKA Collaboration Meeting, 16.12.2014 Anna Ferrari

Components included in the model for MAXSIMA:

• Reactor vessel

• Reactor diaphragm

• Reactor cover

• Above core structures (ACSs)

• Primary pumps

• Primary heat exchangers

• In-vessel fuel handling machines

• Window target

• Silicium doping

Anna Ferrari MAXSIMA Meeting, 27 November 2013 8FLUKA Collaboration Meeting, 16.12.2014 Anna Ferrari

Argon

Analyzed irradiation pattern:

Medium term operation 1 cycle 90 d continuous irradiation, 1 week cooling

Production of Ar-37 (t1/2

= 35 d)

by neutron capture from Ar-36

H*(10) rate (Sv/h) H*(10) rate (Sv/h)

Nitrogen

Production of C-14 (t1/2

= 5700 y)

by fast neutron activation from N-14

Residual activity in argon:

26 Bq/cm3

Residual activity in nitrogen:

0.3 Bq/cm3

A comparison Argon/Nitrogen as plenum gas: residual radiation

Anna Ferrari MAXSIMA Meeting, 27 November 2013 9FLUKA Collaboration Meeting, 16.12.2014 Anna Ferrari

RN contribution to the total specific activity

[Bq/cm3]- EOI 15 y

Activation of the T91 window (FLUKA simulation)

T91 samples Specific activity [Bq/cm3]

EOI 90 days

cooling 1 week

EOI5 years

cooling 30 days

EOI15 years

cooling 1 year

Exit window4.50E+1

21.73E+12 6.95E12 3.28E+12 7.88E+12 2.34E+12

Hexagonal tube(central part)

2.91E+11 1.29E11 5.95E11 3.74E+11 6.70E+11 2.89E+11

Neutron fluence rate (n/cm2 per s)

Anna Ferrari MAXSIMA Meeting, 27 November 2013 10FLUKA Collaboration Meeting, 16.12.2014 Anna Ferrari

In the frame of the European Projects CDT and MAXSIMA we widely used

FLUKA to cope with activation problems.

In the reactor analysis, a coupling MCNPX/FLUKA allowed us to perform

calculations around the reactor core, which had an impact on the design

ANSALDO is a fundamental partner in the MYRRHA Project.

We had a fruitful collaboration in CDT and MAXSIMA

ANSALDO is now in charge of the activation calculations for the MYRRHA

Project (and not only!) and joined the community of the FLUKA users