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ESS TARGET

M. Mancisidor, A. Aguilar, J. Aguilar, L. Mena, M. Magán, F. Sordo R. Vivanco, G.

Bakedano, P. Luna, O. González, F. Jiménez, S. Stepanyan, K. Sjogreen, U. Odén, M. Pérez

Consorcio ESS-Bilbao

11 April 2019, Budapest

Table of contents

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1

2

3

4

Introduction

Target Wheel

Target Shaft

Drive-Unit

Conclusions 5

Introduction

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Introduction

European Spallation Source (ESS) Project Introduction

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ESS construction site in Lund, Sweden (MARCH 2019)

It will be a multi-disciplinary research facility, based on the world’s most powerful long pulsed spallation neutron source

ESS-Bilbao Consortium Introduction

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ESS Work-Packages

European Spallation Source: Target Station Introduction

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Rotating Target Wheel

Target Shaft Drive-Unit

Target Wheel

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Target Wheel

Target Wheel

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CDF Analysis of the Spallation Material

Absorbs the impinging proton beam from the accelerator and transforms it via spallation reaction into fast neutrons, while generating a large amount of heat, radioactive isotopes and prompt radiation

Spallation Material

Helium cooled

Target Wheel

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Spallation Material

In September 2016, Critical Design Review (CDR) of the Spallation Material was held.

W bricks produced by AT&M were delivered to ESS-Bilbao in October 2018.

Quality acceptance process has been completed by CEIT (Yield stress 900 Mpa > 300MPa).

Current Status

Target Wheel

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Cassettes

Tungsten bricks are accomodated and assembled in 36 x SS316L cassettes with grooves drilled on it.

Keep a minimum distance between the bricks for the correct cooling of the spallation material.

No structural function.

In September 2016, Critical Design Review (CDR) of the Cassettes was held.

37 (36 + 1 extra) stainless steel cassettes manufactured by LEADING S.L. already delivered to ESS-Bilbao and inspection plan has been completed.

Current Status

Target Wheel

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Target Vessel

The target wheel is composed of “36 semi-targets” (cassette + spallation material).

Structural component where the cassettes with the W bricks rest and are cooled by helium.

Helium is introduced by a a coaxial pipe and circulates through several open volumes to guarantee an homogeneous inlet pressure in front of the cassette.

Target Wheel

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Target Vessel

Four prototypes of the Target Vessel have been manufactured Main problem High deformations due to the weldings

Current Status

The welding process was reviewed

Insertion of cassette was not feasible

Target Wheel

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Target Vessel

Target vessel’s stress profile shows regions with low stress

The thickness in these areas can be reduced

This reduction of the thickness increases the manufacturing and assembling complexity but the deformation of the vessel will be decreased.

Target Wheel

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Target Vessel

The assembly of the cassettes in the target vessel is possible

The fourth prototype of the target vessel has been completed by Nortemecanica S.L. and the cassette insertion in the target vessel is feasible with minor operation on the cassettes.

Target Wheel

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Target Vessel

Structural component designed and calculated following nuclear rules (RCC-MRx Class 2).

Mechanical analysis of the Target Vessel has been performed including different scenario analysis, fatigue and welding analysis.

Total linear deformation, multiplying the primary loads by 1.5. (elastic-linear analysis)

Total offset deformation, multiplying primary loads by 1.5. (elastoplastic analysis; cycle of loading and unloading)

For any point of the model, it must be checked that the total deformation with the elastic model is higher than the total offset deformation obtained with the elastoplastic model.

Elastoplastic Analysis

Target Shaft

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Target Shaft

Target Shaft

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Target Shaft

Structural component which transmits the rotating movement (23.33 rpm) from the Drive-Unit to the Target Wheel and provides the Target Wheel with coolant.

Helium inlet (40ºC) and outlet (280ºC) channels

Concentric pipes

Neutron streaming through the channels

Helix-shaped shielding

Target Shaft

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Target Shaft

Dose (mSv/h) in the Monolith Vessel

Target Shaft

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CFD Analysis

Target Shaft

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Mechanical Analysis

Structural component designed and calculated following nuclear rules (RCC-MRx N3Rx).

Mechanical analysis of the Shaft has been completed and the proposed design withstands all the loads scenarios studied.

Shaft Design Report is currently under ESS review.

Target Shaft

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Prototype and Current Status

Target Shaft Call for Tender was published on January 25th, 2019. It will be a awarded in the coming weeks.

Current Status

The assembling of both concentric helix-shaped shieldings show a significant risk in the assembling process Manufacturing tolerances are critical

1:5 prototype of the external helix-shaped shielding was manufactured by LEADING S.L. to evaluate the manufacturing tolerances. No significant deviation was observed.

Prototype

Drive-Unit

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Drive-Unit

Drive-Unit

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Drive Unit and Positioning System

Good shielding analysis and design made the radiation level in the drive-unit area low enough to be feasible a standard motor, without any nuclear requirement.

ESS-Bilbao awarded a contract to A.V.S. for the design of the Drive-Unit and positioning system (turnkey contract).

The Drive-Unit assembly contains the necessary elements to produce two of the most important movements of the system

The inner part called “Lifting assembly” Provides the rotation of the wheel.

The outer part called external assembly Provide the vertical adjustment by the guiding system.

Drive-unit

European Spallation Source: Target Station Introduction

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Spallation Material Cassettes Target Wheel Target Shaft Drive Unit

Function Absorbs the impinging proton beam from the accelerator and transforms it via spallation process into fast neutrons, while generating a large amount of heat, radioactive isotopes and prompt irradiation

Structural component where the cassettes with the W bricks rest and are cooled.

Structural component which transmits the rotating movement (23.33 rpm) from the Drive-Unit to the Target Wheel, provides the Target Wheel with coolant and Shield the radiation produced in the spallation reaction in the Target.

Provides the rotation and the vertical adjustment of the Target Wheel.

Material Hot rolled tungsten (W) SS316L SS316L SS316L SS316L

Number 6696 W bricks 36 1 1 1

Coolant Helium Helium Helium Helium -

Special feature Solid bricks of W

-

Rotating Target

Helix shaped shieldings -

6 meter long

Applied rules - - RCC-MRx Class 2 RCC-MRx Class 3 RCC-MRx Class 3

Lifetime 5 years 5 years 5 years 5 years 40 years

Target Station Systems

Conclusions

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Conclusions

Conclusions Conclusions

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In November 2014, ESS-Bilbao was chosen as ESS in-kind partner for designing and manufacturing of the Target Wheel, Target Shaft and Drive Unit.

Spallation Material and Cassettes: CDR approved (September 2016), manufactured, delivered on the ESS-Bilbao site and tested.

Target Vessel: 4 prototypes have been manufactured and lots of lessons have been learned in this process. CDR will be held in June of 2019.

Target Shaft: Call for tenders is ongoing and it will be awarded in the following weeks.

Drive Unit: CDR of the Drive-unit was approved in April 2018 and the manufacturing of this component will start in the following weeks.

Target system workpackage complete delivery on site (ESS Lund) is expected in July 2020.

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Many thanks for your attention!