JULES HOROWITZ REACTOR OPERATION IN MOCK-UP MODES

16th IGORR, November 17-21, 2014, Bariloche

20 NOVEMBRE 2014 | PAGE 1

J. ESTRADE, JY MALO, C. BLANDIN

jerome.estrade@cea.fr

CEA/Cadarache, DEN/DER , F-13108 St Paul Lez Durance

CONTENTS

1.The JHR facility and the experimental capacity

2. Neutronic scheme and design studies

3. Mock-Up operation modes

4. Reactor vessel flexibility and experimental programs capability

5.Conclusion

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1. The JHR facility & experimental capacity

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Hot cells (non destructive examinations)

Experimental cubicles and analysis laboratories

Reactor pool withexamination benches

Core (ΦΦΦΦ 60cm / h 60 cm)and Be reflector

Storage pools

Reactor block

1. The JHR facility & experimental capacity

A modern facility : ► Large experimental areas ► Fission Product Laboratory► Chemistry Laboratory…

I&C: 3 floors, 490 m2

Cubicle: 3 floors, 700 m2

In reflectorUp to 3.5E14 n/cm².s (th)

Fixed irradiation positions (Φ100 mm & Φ200 mm)

and on 6 displacement systems

In coreUp to 5.5E14 n/cm².s (E> 1 MeV)Up to 1.E15 n/cm².s (E> 0.1 MeV)

7 small locations ( Φ Φ Φ Φ ~ 32mm)3 large locations ( Φ Φ Φ Φ ~ 80mm)

LWR fuelexperiments

+ Material ageing

(low ageing rate)

Displacement systems- In water channels (reflector)- Flexible power variations- Experiment decoupled from the core

Material ageing(up to 16 dpa/y)

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A facility dedicated to experimental purposes within a modern safety frame

~20 simultaneous experiments

JHR EXPERIMENTAL CAPABILITIES

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JHR is a reactor with a large flexibility :- 34 to 37 FA- Up to 20 experimental

devices in reflector and in core

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2 - Neutronic scheme and design studies

- Development a specific neutronic scheme to predict and validate the safety criteria

- Qualification of this scheme in EOLE facility- Design studies with nominal experimental devices

loading and with two core configuration (34 and 37 FA)

The neutronic scheme is available to predict each coreconfiguration (number of FA and experimental devices)

3. MOCK-UP OPERATION MODES

250 maximum effective full power days / year

Cycles lasting around 25 days (≅ 10 cycles / year)

Between cycles, shutdown periods for maintenance and periodic test program

Periodic reactor operations under mock-up modes, to perform specific measurements, physics experiments, training and education programs

Nominal reactor vessel configuration:

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At the nominal power (so called “HP state”, up to 100 MW), the

JHR vessel is closed and slightly pressurized

Various low power modes:

Main objectives: fine in-core measurements

BP-CN state: mainly to assess the core performance, at the commissioning phase and during all reactor operation

BP-CF state: mainly to support fuel or material experimental programs, by characterizing the key irradiation parameters in experimental locations

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HP (< 100 %

Nominal Power)

BP-CF (< 2 MW)

CRITICAL

REACTOR STATE (maximum power

available)

BP-CN (< 300 kW)

NON CRITICAL reactor state

AO-CN AO-CF AF

Pumping regime NATURAL CONVECTION OR

VERY LOW FORCED

CONVECTION

LOW FORCED CONVECTION

NOMINAL FORCED

CONVECTION

Reactor Vessel configuration

OPEN Reactor Vessel (Direct access to the core, no upper internals) OR CLOSED

CLOSED (Access only to

experimental locations)

3. MOCK-UP OPERATION MODES

4. Reactor vessel flexibility and experimental programs capability

Reactor vessel configuration, OPEN or CLOSED (nominal state):

Complete access to the core; simpler core components configuration, use of short measurement devices (< 1 m)

Exact geometry representativity of the experimental locations (under nominal reactor conditions)

Dosimetry using mock-up of experimental device to validate the design

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4. Reactor vessel flexibility and experimental programs capability

Experimental programs capability

OPEN reactor vessel configuration: fully devoted to perform neutron flux and nuclear heating mapping, power distributions, spectral indices, … by minimizing the fluxes disruption

CLOSED reactor vessel : to provide complementary measurements of the irradiated conditions inside the experimental locations or test devices, exactly in the geometry under nominal conditions

Both configurations: education and training program s

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4. Reactor vessel flexibility and experimental programs capability

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4. Reactor vessel flexibility and experimental programs capability

CARMEN test devices

Mobile devices (axially moved)

Simultaneous on-line measurements of the relevant physical parameters, using various sensors (SPND, Calorimeters, fission chambers…)

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5. CONCLUSION

The low power modes of the JHR provide a large flexibility:

Selection of the most suitable reactor vessel configuration : OPEN withcomplete access to the core or CLOSED, as under nominal reactor conditions

Choice of the most relevant reactor power and coolant convection conditions : up to 300 kW (BP CN state, the core being cooled by naturalconvection) or up to 2 MW (BP CF, with low forced convection)

In order to:

Perform fine core nuclear measurements, to support fuel and material experiments or to assess the core performance.

Be used for educational and training programs

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