Some essential features of the TAPIRO

Fast-Neutron Source Reactor

located at ENEA-CR Casaccia (Rome)

R. Rosa, A. Santagata, M. Carta, O. Fiorani

ENEA* – Via Anguillarese, 301 – 00123 Rome – Italy

* Italian National Agency for New Technologies,

Energy and Soustainable Economic Development

12th IGORR October 28– 30, 2009, Beijing, P.R.China

TAPIRO

Content

October 28– 30, 2009, Beijing, P.R.China 212th IGORR 2009

TAPIRO

• History

• Main Features

• Facility Schemes

• Neutron Data

• Recent Activities

• Incoming Modifications

• Planned Activities

• Conclusions

The Casaccia Research Center

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TAPIRO

October 28– 30, 2009, Beijing, P.R.China 12th IGORR 2009

History

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TAPIRO

• Fast source reactor

• Based on the concept of AFSR (Argonne Fast

Source Reactor - Idaho Falls)

• Designed by ENEA’s staff

• Start-up: 1971

• First Activities: fast reactor shielding experiments

biological effects of fast neutrons

October 28– 30, 2009, Beijing, P.R.China 12th IGORR 2009

Reactor: Main Components

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TAPIRO

CORE Cylindrical: diameter 125.8 mm

height 109.5 mm (2/3 fixed – 1/3 mobile)

FUEL Uranium-molybdenum alloy (98.5% U – 1.5% Mo)

Density: 18.5 g cm-3

Enrichment: 93.5% U235

Operative mass: 22107.42 g/U235

CLADDING Stainless steel: thick 0.5 mm

REFLECTOR Cylindrical Inner Reflector: diameter 348 mm

Outer Reflector: diameter 800 mm

Overall Height: 700 mm

Material: Copper

Weight: 2600 kg

October 28– 30, 2009, Beijing, P.R.China 12th IGORR 2009

Reactor: Auxiliary and Irradiation Systems

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TAPIRO

COOLING

SYSTEM

Forced He: 100 g/sec @ 7.5 ata

Heat Exchanger + Refrigerator

Inlet core temp: 35° C - Outlet 25° C

BIOLOGICAL

SHIELD

Shape: near spherical

Thickness: 1.75 m

Material: high density borate concrete

Density: 3.7 kg dm-3

IRRADIATION

CHANNELS

3 channels at the reactor midplane

1 tangential (to the top edge of the core)

THERMAL

COLUMN

Max Volume: 1.6 m3

2 piercing channels

October 28– 30, 2009, Beijing, P.R.China 12th IGORR 2009

The Big Concrete Sphere

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TAPIRO

October 28– 30, 2009, Beijing, P.R.China 12th IGORR 2009

TAPIRO: Horizontal Section

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TAPIRO

October 28– 30, 2009, Beijing, P.R.China 12th IGORR 2009

TAPIRO: Vertical Section

TAPIRO

October 28– 30, 2009, Beijing, P.R.China 12th IGORR 2009 9

Accessing the Thermal Column

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TAPIRO

October 28– 30, 2009, Beijing, P.R.China 12th IGORR 2009

Schematic Horizontal Cut at Reactor Midplane

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TAPIRO

SR

RR SR

SHR

SHR

He

Core Radial Ch

Outer

Reflector

Inner

Reflector

Dia

me

tra

l Ch

an

ne

l

October 28– 30, 2009, Beijing, P.R.China 12th IGORR 2009

Schematic Vertical Cut with Control Rods

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TAPIRO

He Cooling

Channell

Cu Reflector

He Cooling

Upper Core

Fixed

Lower Core

Movable

October 28– 30, 2009, Beijing, P.R.China 12th IGORR 2009

Schematic Vertical Cut with Control Rods

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TAPIRO

He Cooling

Channell

Cu Reflector

He Cooling

Upper Core

Fixed

Lower Core

Movable

October 28– 30, 2009, Beijing, P.R.China 12th IGORR 2009

Schematic Vertical Cut with Control Rods

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TAPIRO

He Cooling

Channell

Cu Reflector

He Cooling

Upper Core

Fixed

Lower Core

Movable

October 28– 30, 2009, Beijing, P.R.China 12th IGORR 2009

Schematic Vertical Cut with Control Rods

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TAPIRO

He Cooling

Channell

Cu Reflector

He Cooling

Upper Core

Fixed

Lower Core

Movable

October 28– 30, 2009, Beijing, P.R.China 12th IGORR 2009

Reactor Component Distances from Core

Vienna, 12-16 Oct. 2009 16TM on Specific Applications of RR: Provision of Nuclear Data

TAPIRO

Thermal Column

Distance

Radial Channel

Calculated Neutron Fluence Rate per Energy Groups

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1,00E-02

1,00E+01

1,00E+04

1,00E+07

1,00E+10

1,00E+13

0 10 20 30 40 50 60

Neu

tro

nF

luen

ce [

n c

m-2

s-1

]

Distance from the Core Axis [cm]

1.45E+07

3.68E+06

2.23E+06

1.35E+06

8.21E+05

4.98E+05

3.02E+05

1.83E+05

1.11E+05

6.74E+04

4.09E+04

2.48E+04

1.50E+04

9.12E+03

5.53E+03

3.36E+03

2.04E+03

1.23E+03

7.48E+02

4.54E+02

2.75E+02

1.01E+02

2.26E+01

3.06E+00

4.14E-01

Sum

Radial

Channel 1Radial Channel 2 Thermal Column

Energy (eV)

TAPIRO

October 28– 30, 2009, Beijing, P.R.China 12th IGORR 2009

• Characterization of N-16 counters devoted

to monitoring

• Neutron radiation damage on components

for the electromagnetic calorimeter (ECAL

CERN LHC- Project)

• BNCT and neutron radiation effects on

cancerous cells

Activities up to now

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TAPIRO

October 28– 30, 2009, Beijing, P.R.China 12th IGORR 2009

At full reactor power [5 kW]

• Core center

– Total core integrated neutron source strength: 3×1014 n/s

– Total neutron fluence rate: 4×1012 n · cm-2 · s-1

8×1011 n · cm-2 · s-1 > 1.35 Me V

• Entrance of the thermal column

– Total neutron fluence rate: 1.5×1010 n · cm-2 · s-1

4×107 n · cm-2 · s-1 > 1.35 MeV

Neutron Data Extimated by Calculation

Vienna, 12-16 Oct. 2009 19TM on Specific Applications of RR: Provision of Nuclear Data

TAPIRO

BNCT Thermal Column Modification

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TAPIRO

October 28– 30, 2009, Beijing, P.R.China 12th IGORR 2009

Thermal Column Scheme for BNCT

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TAPIRO

October 28– 30, 2009, Beijing, P.R.China 12th IGORR 2009

BNCT Shielding

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TAPIRO

Reactor Hall

Control Room

October 28– 30, 2009, Beijing, P.R.China 12th IGORR 2009

• Dismantling the BNCT Shielding and

Thermal Column Internals

• Return to the Original Reflector

• Thermal Column Reshape

• Revision of the MCNP Model of the

Reactor (Cooperation with La Sapienza University – Rome)

• Experimental Assessment of the MCNP

Neutron Fluence Estimations

• Single Crystal Diamond Detectors Test

Planned Activities

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TAPIRO

October 28– 30, 2009, Beijing, P.R.China 12th IGORR 2009

• Chemical vapor deposited single crystal

diamond in a p-type/intrinsic/metal/6Li

layered structure

• First test in thermal field in TRIGA at 1

MW (109 neutrons/cm2/s)

• Excellent linearity observed

• Test in fast field is requiredM. Marinelli, E. Milani, G. Prestopino, A. Tucciarone, C. Verona-Rinati, M.

Angelone, D. Lattanzi, M. Pillon, R. Rosa, E. Santoro - Synthetic single

crystal diamond as a fission reactor neutron flux monitormg - Applied

Physics Letters 90, 183509 (2007)

Single Crystal Diamond Detectors Test

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TAPIRO

October 28– 30, 2009, Beijing, P.R.China 12th IGORR 2009

Single Crystal Diamond Detectors Test

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TAPIRO

Linearity 10 kW – 1 MW

October 28– 30, 2009, Beijing, P.R.China 12th IGORR 2009

Ref. # Loading Content [g]

1880 U-235 10

1995 U-235 50

2019 U-238 132

1997 Pu-239 30

1998 Np-237 30

Detectors Availability

Vienna, 12-16 Oct. 2009 26TM on Specific Applications of RR: Provision of Nuclear Data

TAPIRO

Wide Activation Foils Availability

Small Fission Chambers

• Different patterns of neutron field

– investigations of selected phenomena radiation

damage

• Static and dynamic regimes:

– parametric studies on ADS prototypical fuel in

thermal column, eventually with a converter zone.

• Steady conditions

– influence of fuel/Pb ratio on neutronic behavior of

fuel-lead matrices.

• Dynamic conditions

– absolute reactivity measurement conditions

relative to source-jerk techniques

SUPPORT TO ADS R&D

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TAPIRO

October 28– 30, 2009, Beijing, P.R.China 12th IGORR 2009

• Benchmark for validate neutronic codes for systems with significant

spectral changes within the core (HTGR and Fast Systems)

• Traverses in graphite and lead columns,

– Possible removal of a sector of the outer copper for a very hard

neutron spectrum.

– graphite column where spectrum gradually softens up to thermal

– lead column where the spectrum softens from hard to epithermal

• Different materials interposed (U-nat, Pb, Fe, etc.): spectrum transition

conditions at interface points between regions with different

compositions.

• Activation foils: threshold energies in the fast, intermediate and

epithermal regions.

• Quantitative gamma spectrometry

• Fission Chambers based Techniques

BLANKET EXPERIMENTS 1/2

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TAPIRO

October 28– 30, 2009, Beijing, P.R.China 12th IGORR 2009

Analogous experiments on TAPIRO performed in the early 70's:

• Studies of the propagation of neutrons along the axis of a

large sodium tank inserted in place of the graphite column.

• Measurement campaign in collaboration with CEA Cadarache

for the fast reactor program

Similar purpose: testing the ability of neutronic codes to

reproduce the measured quantities.

The experimental data are now included in the NEA

documentation (International Reactor Physics Experiment

Evaluation Project -IRPhEP)

BLANKET EXPERIMENTS 2/2

Vienna, 12-16 Oct. 2009 29TM on Specific Applications of RR: Provision of Nuclear Data

TAPIRO

• Enhance the Reactor Activity in

connection with the new Italian Way

towards NPP

• Cooperate with Universities and

Research Centers for the next

Generation of Nuclear Experts

• …. Outcomes of the present TM

Conclusion

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TAPIRO

Main Targets of the Future Activities

October 28– 30, 2009, Beijing, P.R.China 12th IGORR 2009

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TAPIRO

October 28– 30, 2009, Beijing, P.R.China 12th IGORR 2009