Yoro TALL Santiago de Compostela (Spain) June 7 – 10, 20061 Second IP EUROTRANS Internal Training...

Yoro TALLSantiago de Compostela (Spain) June 7 – 10, 2006 1

Second IP EUROTRANS Internal Training Course on Nuclear Data for Transmutation: status, needs and

methods.

Investigation of the production of gas and volatile elements in

lead-bismuth ADS spallation targets.

Yoro TALL, SUBATECH Nantes, France


Contents

MEGAPIE project

Motivations of ISOLDE experiment

ISOLDE facility & Overview of the experiment

Different techniques of measurement

Results

Conclusions and future works


MEGAPIE project

MEGAPIE an initiative from European institutions (among them PSI, FZK, CEA, CNRS, ENEA) and Japanese institution (JAERI).

MEGAPIE (1.74 mA, 575 MeV) is an important step to the validation of PbBi ADS target.

Its main objectives is to design, build, operate a spallation PbBi target under protons beam irradiation.

The target is now installed in the SINQ facility and one year irradiation is expected.


Motivations of ISOLDE Experiments

During MEGAPIE irradiation, gas and volatile elements are produced, both stable and radioactive.

Calculated values of stable gases indicated a production of about 1 l/month (mainly stable H and 4He).

The radioactive gas will be handled by a specially designed cover gas system. It is important to experimentally verify these predictions.

There is the need to know the production rate of specific radioisotopes for the disposal of the target.

Such an experiment offers a chance to benchmark widely used codes such as FLUKA and MCNPX.


ISOLDE Facility (CERN, SUISSE)

Collection foils and Faraday cup

Tape station

PSB (Protons Synchrotron Booster)LBE

target


Overview of the experiment

LBE

Energy protons beam : 1.0 GeV and 1.4 GeV.

Pulsed protons beam.

Repetition rate : 14.4 s

Intensity of beam : 1013 protons/pulse.

Lists of isotopes measured6,8He

19,23,24Ne

41,43,44Ar

75,...,90Kr

112,..,137Xe

200,...,211At

186,...,205Hg

Experimental parameters


Lead-Bismuth target

Cylinder L = 20 cm, r = 1 cm

Mass Pb-Bi : 547 g

Temperature target : 600 °C and 400 °C

Schematic view of the volatile elements release

Protons beam diffusion

effusion



accelerator targetprotons

spallation

Volatile

elements

Plasmasource

ionisation ions Mass

separator

detector

Online measurement

Off line measurement



Different techniques of measurements

Off line -spectroscopy (collection station, GLM) : medium-long lived-isotopes


Different techniques of measurements

HPGe (gamma)scintillator (beta)

Beam line

Online -spectroscopy (tape station) : short and medium long-lived isotopes


Astatine

Yields as function of temperature of 123Xe and 204,209,210At.

Temperature dependence

Po is not released from the target but observed ONLY from At decay

Xenon

1,0E+03

1,0E+04

1,0E+05

1,0E+06

1,0E+07

1,0E+08

0 100 200 300 400 500 600 700

Target temperature C

Yie

ld (a

tom

s/m

C)

210At209At204At

1,0E+06

1,0E+07

1,0E+08

0 100 200 300 400 500 600 700Target temperature C

Yiel

d (a

tom

s/m

C)

meas no1

meas no2

meas no3


1,0E+07

1,0E+08

1,0E+09

200 250 300 350 400 450 500 550 600 650Target temperature C

Yie

ld (

ato

ms

/m

C)

203Hg

Temperature dependence

Mercury

For Hg the release at 600 ºC seems to be complete, not as for Xe.


Release measurements of Neuhaussen

400 600 800 1000 1200

0.0

0.2

0.4

0.6

0.8

1.0

Fra

ctio

nal r

elea

seTemperature [K]

Iodine

400 600 800 1000 1200 1400

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

0.65 g samples 0.14 g samples

Fra

ctio

nal r

elea

se o

f Po

Temperature [K]

Polonium

Polonium starts to be released at about 1000 K

A small part of iodine released at 800 K


Good agreement between data obtained with the three techniques

Mercury production rates 2004 data

Results

Mass number


Good agreement between results and simulations.

Mass number

Pro

duct

ion r

ate

s (A

tom

s/mC

)

Results

Mercury production rates data 2005

1,00E+07

1,00E+08

1,00E+09

1,00E+10

1,00E+11

1,00E+12

190 195 200 205 210

MCNPX(BERTINI/DRESNER)-FISPACTOn line gamma-spectroscopy

Off line gamma-spectroscopy

FLUKA-ORIHET


Good agreement between results and simulations.

Pro

duct

ion r

ate

s (A

tom

s/m

C)

Results

Mass number

Xenon production rates

1.000E+06

1.000E+07

1.000E+08

1.000E+09

1.000E+10

120 122 124 126 128 130 132 134

MCNPX(BERTINI/DRESNER)-FISPACT

MCNPX(INCL4/ABLA)-FISPACT

FLUKA-ORIHET

Off line measurements


1.00E-05

1.00E-04

1.00E-03

1.00E-02

1.00E-01

1.00E+00

30 80 130 180 230

INCL4/ABLA 1.4 GeV

INCL4/ABLA 1.0 GeV

Bertini/Dresner 1.0 GeV

Bertini/Dresner 1.4 GeV

In the A~125 mass region, the two models are close at 1 GeV, while at 1.4 GeV Bertini/Dresner is higher than INCL4/ABLA

Mass number

Results

Comparison data and calculations at 1.4 GeV Xenon production rates (2004)

Yie

lds(

Ato

ms/

pro

ton)

Mass number


Good agreement between simulations.

Confirmation of the small release of iodine

Pro

duct

ion r

ate

s (A

tom

s/mC

) Results

1,000E+06

1,000E+07

1,000E+08

1,000E+09

1,000E+10

114 116 118 120 122 124 126 128

MCNPX(BERTINI/ DRESNER)-FISPACT

MCNPX(INCL4/ ABLA)-FISPACT

FLUKA-ORIHET


Iodine production rates

Mass number


Pro

duc

tion

rate

s A

tom

s/mC

Fair agreement with simulations and data (calculations factor 2-3 higher)

Not measured in 2004

Possible imperfection on models or not complete release of noble gases

Results

1.000E+07

1.000E+08

1.000E+09

1.000E+10

76 78 80 82 84 86 88 90

MCNPX(BERTINI/ DRESNER)-FISPACT

MCNPX(INCL4/ ABLA)-FISPACT

FLUKA-ORIHET

On line measurements


Krypton production rates

Mass number


Good agreement between data (off line and on line measurements) and simulations.

No Po release observed, ONLY from decay of At.

Temperature dependence observed for all isotopes. Possible not complete release for noble gases at 600 °C.

Agreement with release experiments of Neuhausen.

Only about less than 15 % of iodine released (compared to calculations).

Validation of Monte Carlo codes used for the neutronic design

Very important results obtained in the frame of the realization of the XT-ADS.

conclusions


Future works

Finalisation of data analysis for tape station (release shape)

Post irradiation analysis of the target (mass and gamma spectroscopy)

Evaluation for the XT-ADS the production rates of residues (activity, radiotoxicity, emissions of volatile elements…) by calculations with MCNPX coupled with the different options (BERTINI, INCL4, ISABEL, CEM2K)

Yoro TALL Santiago de Compostela (Spain) June 7 – 10, 20061 Second IP EUROTRANS Internal Training...

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Transcript of Yoro TALL Santiago de Compostela (Spain) June 7 – 10, 20061 Second IP EUROTRANS Internal Training...