Decontamination and dismantling of large plutonium-contaminated glove boxes

European Commission Directorate-General For The Information Society And Media Directorate-General For Research And Innovation

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Nuclear energy and safety

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• Publié par: EUROPEAN-COMMISSION-DIRECTORATE-GENERAL-FOR-THE-INFORMATION-SOCIETY-AND-MEDIA-DI
• Nombre de lectures: 128
• Langue: English
• Poids de l'ouvrage: 4 Mo

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Commission of the European Communities
nuclear science
and technology
Decontamination and dismantling of large
plutonium-contaminated glove boxes Commission of the European Communities
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Decontamination and dismantling of large
plutonium-contaminated glove boxes
J. Draulans
Belgonucléaire SA
Europalaan 20
B-2480 Dessel
Final report
This work was performed within the framework of the European Communities' research
programme on the decommissioning of nuclear installations, Section C 'Testing
of new techniques under real conditions'
Contracts Nos FI1D-0024-B and FI1D-0058
Directorate-General
Science, Research and Development
1991 EUR 13633 EN Published by the
COMMISSION OF THE EUROPEAN COMMUNITIES
Directorate-General
Telecommunications, Information Industries and Innovation
L-2920 Luxembourg
LEGAL NOTICE
Neither the Commission of the European Communities nor any person acting
on behalf of then is responsible for the use which might be made of
the following information
Cataloguing data can be found at the end of this publication
Luxembourg: Office for Official Publications of the European Communities, 1991
ISBN 92-826-2991 -0 Catalogue number: CD-NA-13633-EN-C
© ECSC-EEC-EAEC, Brussels · Luxembourg, 1991
Printed in Belgium ABSTRACT
This report describes Che work performed in the frame of two C.E.C.-con­
tracts n" FI1D-002Ú00-B "Decommissioning of very large glove boxes" and n"
FI1D-0058 "Decommissioning of a complex glove box structure to be dis­
mounted partially on place".
The latter contract could not be accomplished due to reasons, foreign
to BELGONUCLEAIRE, the residual part of the contract was then dedicated to
some test work on freon cleaning of glove boxes and on some preliminary
test work with frozen C0£ particles on non radioactive samples.
Detailed information is given about each glove box. The selection of
the solution "Transportation of the glove boxes to a specialized dismant­
ling plant" is justified. The necessary contacts inside the BELGO­
NUCLEAIRE MOX plant and between the latter and other organizations are
explained.
The problems of manipulating large gloves are listed and the retained
solution of building a so called "Stiffening frame around each glove box"
is described.
Furthermore information is given concerning required operators time
for cleaning, manipulating, packing and dismantling together with received
doses and quantities of waste produced.
Concerning the glove box unit partially to be dismounted on place, de­
tailed information is given about the way the glove boxes have been treat­
ed prior to this partial dismantling on place and about the way this
partial dismantling has been performed.
From these results one can conclude that such a delicate task can be
performed without major difficulties.
Finally information is given of the decontamination test of a highly
Pu contaminated glove box with freon with rather poor results and of the
preliminary CO2 blasting tests on non active samples.
- Ill -CONTENTS
Page
ABSTRACT I 11
LIST OF TABLESX
LIST OF FIGURES XI
2. OBJECTIVE + SCOPE, WORK PROGRAMME, STRATEGY AND ORGANIZATIONS INVOLVED 1
1.1. Objective and scope
1.2. Work programme
1.2.1. Conditioning of the glove boxes 1
1.2.2. The transportation of the glove boxes 2
1.2.3. final dismantling 3
1.3. Remark
2.4. Strategy : choice between dismantling on site versus dismantling
in a specialized institute J
1.5. Departments of BELGONUCLEAIRE and foreign organizations involved
in the dismantling tasks
2. DATA CONCERNING THE GLOVE BOXES TO BE DISMANTLED 6
2.1. Data concerning the 5 individual glove boxes
2.2. glove box unit 13
2.3. Pu content, values and determination, and Γυ isotopie composition 17
3. TECHNICAL "SOLUTION" FOR THE REQUIRED MANIPULATIONS OF THE GLOVE BOXES
BETWEEN THEIR ORIGINAL LOCATION AND THE ALPHA ROOM IN THE DISMANTLING
PLANT 19
3.1. For the individual glove boxes · "
- Stiffening frame I-»
- Main modifications to room 11 and building <-U
- Disconnection of glove boxes 20
- Disconnecting glove box Al from the one beneath 24
3.2. For the glove box unit
3.3. Glove box cleaning operation
3.3.1. Dry cleaning
3.3.2. Wet5
3.3.3. General information concerning the cleaning of the 5 indi­
vidual glove boxes
3.3.4. Encountered difficulties
3.4. Attempt to define a lower limit below which the glove boxes do not
have to be cleaned 31
3.4.2. Gamma dose rate measurements
3.4.2. Registration of the required man-hours and the received
body and finger doses4
3.4.3. Ratios between gamma dose rate reduction, required man-
hours, received body and finger doses 3
V 3.4.4. Attempt to define a lower limit below which the glove boxes
34 have not to be cleaned
38 THE DECOMMISSIONING OF THE GIOVE BOXES
38
4.2. For the 5 individual glove boxes
ά. 1.1. Successive steps in the decommissioning tasks at the BELGO­
38
NUCLEAIRE plant
38 ά.1.2. Fastening of the equipment inside the glove box
4.2.3. Placing of adhesive transparent plastic foil of the glove
box window
39
4.2.4. Mounting of the stiffening frame around the glove box and
fixing of the heavy equipment inside the glove box onto the
stiffening frame
39 4 1 5 . Covering of all surfaces inside the glove box by means of a
fixing spray j"
4 1 6. Final check of all fixing and fastening systems and of the
42 layer of "spraylat"
4 Filling-up of all voids inside the glove box by means of 1 7.
42 polystyrene "chips"
4 1 8. Lifting, rotating and placing the glove box on the package
42 bottom
44 4 Packing of the glove boxes 1 9 .
4 10. Data collected during the decommissioning operations of 1
44 the glove boxes
45 h.2. For the glove box unit
ά.2.1. The lifting device 4Í3
4.2.2. partial dismounting of the glove box unit and collected
45 data
4.3. The transportation of the glove boxes 59
^.3^.1. Itinerary followed between BELGONUCLEAIRE and the SCK/CEN
5
si te
5
4.3.2. Means of transportation
4.3.3. Regulatory requirements and competent authority approvals 5y
4.3.4. Third party nuclear liability insurance oc
4.4. Cost distribution for the work at the BELGONUCLEAIRE plant 62
6
, DISMANTLING OF THE GLOVE BOXES AT THE S.CK./C.E.N. DISMANTLING PLANT
6
5.1. Dismantling procedures
5.1.1. Procedure 1 : Provisional storage of the glove boxes3
5.1.2. 2 : Unpacking the glove box 6
5.1.3. 3 : Transport of the glove box out of the storage
hall towards the "reception center". Introduction of the
64 glove box in lock chamber "reception center"
5.2.4. Procedure 4 : Bringing the glove box in the lock chamber of
the alpha zone UH
5.2. Dismantling, destruction and conditioning of the glove boxes in the
alpha chamber 66
5.2.1. Successive main working steps
5.2.2. destruction steps
5.2.3. Destruction crew7
5.2.4. Dismantling glove box A13
5.2.5. Al
5.2.6. glove box AIO8
5.2.7. Dismantling glove box All 69
5.2.8. glove box A12
5.3. Air contamination level in the alpha room 70
5.4. Data per glove box for the whole operation
"Decommissioning + Dismantling"
VI 6. CONCLUSIONS AND ADVICES 76
6.1. Problems encountered
6.2. Conclusions and recommandations
6.3. Attempt to define a lower limit below which the glove boxes do not
have to be cleaned. '·
7. FREON AND C02 DECONTAMINATION TESTS8
7.1. Freon test on a contaminated glove box 7
7.1.1. Residual contamination, isotopie composition of the pluto­
nium and measurement of the smearable contamination 'o
7.1.2. Freon and freon cleaning equipment 81
7.1.3. Test glove box preparation
7.2.4. Freon cleaning test results
7.1.5. Obtained results 83
7.1.6. Conclusion
7.2. CO2 blast test on non-active samples
7.2.1. Definition of the representative samples of glove box mate­
rials and structures
7.2.2. CO2 blasting tests on different non-active samples 86
7.2.3. Obtained results
7.2.4. Comments and conclusions8
VII