atw 2018-05v6

inforum

atw Vol. 63 (2018) | Issue 5 ı May

| | Fig. 5.

Sorting of temporarily stored operational waste using AZURo

(Sources: Orano GmbH and RWE Power AG, Biblis).

• ability for intervention in each

situation, and

• health physics aspects.

As a result from the expert’s supervision,

there were no safety-related

concerns against employment of the

remotely operated underwater robot

system AZURo.

The mission of the field test was

divided into 2 packages:

• Sorting of disorderly stored operational

waste (flow restrictors

and absorber element heads) into

appropriate disposal containers

• Segmenting and sorting of core

instrumentation detector fingers

into appropriate disposal con tainers

4.1 Sorting of disorderly

stored operational waste

Sorting of flow restrictors and absorber

element heads was performed

by means of the robot system

(­Figure 5). For this an appropriate

gripper was adapted to the robot

system. Using that tool, one piece

after another from the stock of flow

restrictors and absorber element

heads lying disorderly on the bottom

of the spent fuel pool was picked up.

Each item was then transferred into

the disposal container after successful

separation and dose rate determination.

For this application, the robot

was remotely controlled.

4.2 Segmenting and sorting

of core instrumentation

detectors fingers

The following work steps have been

applied to cut and pack the core

instrumentation detector fingers

(Figure 6):

• For determination of the cutting

length the detector finger was positioned

on the cutting tool installed

at the robot arm. The cutting tool

was then moved down vertically

until the cutting length for this

segment was reached. In doing so,

each finger was simultaneously

tracked according to the movement

of the cutting tool until the

length of the segment was reached.

• Subsequently, the crosscut segment

was cut and clamped by

means of the cutting tool.

• The cut-off segment was then

transferred to an appropriate

disposal container also using the

robot system.

4.3 Field Test in a nuclear

power plant – Summary

The testing in a nuclear power plant

proved the capability of the system

under realistic conditions.

The following significant advantages

of this system for underwater

application in comparison with manually

operated tools could be shown:

• High speeds.

• Exact compliance with the given

step sequences and trajectories;

high degree of safety (guarantee of

the integrity of the spent fuel pool

liner and of the fuel assembly

racks); malfunction caused by

breakdown of component(s) prevented

by the graduated safety concept,

that means by combination of

technical and administrative measures.

Moreover:

• High availability (tightness in a

depth of 14m), in the present case

during an application for a period

of ten weeks.

• The preparatory measures being

initially rather extensive (e.g. for

modelling, programming, arranging

and calibrating of the components

and for system checks) are

compensated during execution and

result in economic advantages (time

and cost savings) if there is a larger

extent of similar material quantities

to be dismantled and packed.

| | Fig. 6.

Segmenting and sorting of core instrumentation detectors fingers using

AZURo (Sources: Orano GmbH and RWE Power AG, Biblis).

5 Future prospects

The developed underwater robot

system AZURo clearly highlighted its

assets during the field test. The elaborated

fundamentals ease the adaption

of the robot system to other applications.

For instance, the system can be

used for handling operations (loading

of machines, charging of disposal

canisters etc.) during decommissioning

of nuclear power plants or service

projects as well. Cutting tools (saws,

cutting nozzles etc.) can be very well

adapted at reasonable effort.

The diversity of facilities is a major

asset of AZURo because of the robot

only being a “tool carrier” and being

able to handle the carried tools

arbitrarily in its workspace.

Acknowledgement

The research project AZURo has been

funded by German Federal Ministry

of Education and Research (BMBF)

(support code 02S9082A).

Post Research

After finalizing the research project

the underwater robot system AZURo

is qualified and ready for use. Orano

GmbH has been contracted for the

cutting and packing of the core waste

and the RPV internals of four NPPs.

First application of AZURo will be in

Brunsbüttel NPP.

AZURo is an innovative dose, time and

cost saving equipment; ready to use!

Authors

Gunnar Fenzel

Alexandra Sykora

Orano GmbH

Henri-Dunant-Str. 50

91058 Erlangen, Germany

Dr. Dietmar Nieder

RWE Power AG

Kraftwerk Biblis

Biblis, Germany

OPERATION AND NEW BUILD 307

Operation and New Build

Applications of Underwater-Robotics in Nuclear Power Plants ı Gunnar Fenzel, Dr. Dietmar Nieder and Alexandra Sykora

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