Explanatory Memorandum to COM(1978)167 - Programme concerning the decommissioning of nuclear power plants (submitted to the Council by the Commission)

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ARCHIVES HISTORIQUES DE LA COMMISSION

COLLECTION RELIEE DES DOCUMENTS 'COM'

COM (78)167

Vol. 1978/0055

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Conformement au reglement (CEE, Euratom) n° 354/83 du Conseil du ler fevrier 1983 concernant I’ouverture au public des archives historiques de la Communaute economique europeenne et de la Communaute europeenne de I’energie atomique (JO L 43 du 15.2.1983, p.

1), tel que modifie par le reglement (CE, Euratom) n° 1700/2003 du 22 septembre 2003 (JO L 243 du 27.9.2003, p.

1), ce dossier est ouvert au public. Le cas echeant, les documents classifies presents dans ce dossier ont ete declassifies conformement a I’article 5 dudit reglement.

In accordance with Council Regulation (EEC, Euratom) No 354/83 of 1 February 1983 concerning the opening to the public of the historical archives of the European Economic Community and the European Atomic Energy Community (OJ L 43, 15.2.1983, p.

1), as amended by Regulation (EC, Euratom) No 1700/2003 of 22 September 2003 (OJ L 243, 27.9.2003, p.

1), this file is open to the public. Where necessary, classified documents in this file have been declassified in conformity with Article 5 of the aforementioned regulation.

In Obereinstimmung mit der Verordnung (EWG, Euratom) Nr. 354/83 des Rates vom 1. Februar 1983 uber die Freigabe der historischen Archive der Europaischen Wirtschaftsgemeinschaft und der Europaischen Atomgemeinschaft (ABI. L 43 vom 15.2.1983, S.

1), geandert durch die Verordnung (EG, Euratom) Nr. 1700/2003 vom 22. September 2003 (ABI. L 243 vom 27.9.2003, S.

1), ist diese Datei der Offentlichkeit zuganglich. Soweit erforderlich, wurden die Verschlusssachen in dieser Datei in Obereinstimmung mit Artikel 5 der genannten Verordnung freigegeben.
COMMISSION OF THE EUROPEAN COMMUNITIES


COM(78) 167 final.

Brussels, 20 April I978

PROPOSAL FOR A COUNCIL DECISION

adopting a programme concerning the decommissioning of nuclear power plants

(submitted to the Council by the Commission)

COM(78) 167 final


CONTENTS:


Contents

1.

PREFACE


PART I:

PART II:

Annex I: Annex II:

2.

Situation and prospects regarding decommissioning of


nuclear power plants •

3.

1. Introduction


4.

2. Experience with decommissioning


5.

3. Decommissioning studies


6.

4. Decommissioning techniques


7.

5. Estimation of the quanties of radioactive waste from decommissioning


6. Guiding principles .

8.

Programme proposal ‘


PREFACE

On May 1977 "the Council approved, as part of the Community's action programme on the environment the principle of an action concerning the decomissioning of nuclear power plants. It asked the Commission to pool and to analyse earlier studies and experience and to present, on the basis of the results of this work, appropriate proposals to the Council.

The present document has been drawn up with the help of a group of national experts. Part I contains mainly an analysis of earlier studies and experience and Part II a proposal for a funded action programme.

The scope of the analysis and the proposal has been restricted to nuclear power plants, excluding other nuclear installations such as research reactors and fuel cycle facilities. However, available relevant experience with such other installations has been taken into account. It may also be noted, that the results from the proposed action are expected to be of benefit to other installations too.

PART I : SITUATION AND PPOSPFCTS REPAPDIi-lG DECOMMISSIONirC OF NUCLEAR . \

prM/>EP PLANTS ' •

1. Introduction ,

Decommissioning of nuclear plants means their safe disposition after ' retirement from service. Its ultimate objective is the unrestricted release of the plant site for other uses. One must however keen in mind that only a relatively small part of a nuclear power station <15 to 20 %) will give rise to problems associated with the presence of radioactive matter.

Every nuclear power plant will some time arrive at the end of its useful life/ but the reasons for retiring a plant from service may vary. A prototype plant may be decommissioned when it has achieved its objective, or whort the objective has been abandoned. Commercial plants will be retired from service when either economic or safe operation is no longer possible. Such if situation could also he brought about by an incident if rehabilitation

■ ’ . . ‘ 'v '

of the plant proved too costly or impossible due to radiation. . ,

After a plant has been retired from service, the nuclear fuel, radioactive materials in process and radioactive waste produced in normal operation should first be removed by routine operations. As regards the further

procedure, three staqes of decommissioning have been defined in the frame of r . • . / the International Atomic Energy Agency, namely : -

S t comm_i 3 s_i cn_2 nQ ■ . .

The plant is practically kcot intact. The mechanical opening systems (valves, nluos, etc.) of the first contamination barrier are perma- . - nently blocked and sealed. .The Diant is under surveillance and ins- . pcctions are carried out to check that it remains in good condition.

S£33£_2_!?2££3!Ui5.§,i£Dil32 ,. ■ ; •

9.

The primary contamination barrier is reduced to minimum size and


■. ’ . i •< '

sealed, removing all parts which can be easily dismantled. The biolo-gi.cal shield '(e.g. concrete) is extended so that it - completely - surrounds the harrier. . . ' 1 : '

After decontamination to acceptable levels the containment building - can be removed. The other parts of the plant (buildings or equipment) can be dismantled or converted for new purposes. Surveillance around

the barrier is necessary but can be relaxed as compared with Stage 1.

. * • ' .

External inspection of the sealed part should be performed.

_Staqe _3 djecjammijsjk>ning .

All remaining parts-of the plant; the activity of which remains significant despite decontamination procedures, are removed. The plant is then released without restrictions. No surveillance or inspection is necessary from the point of view of radiological protection.

Stages 1 to 3 are, though not completely corresponding, sometimes also referred to as,"mothballing", 'entombment' and "(complete) remo*? vsl", respectively.

10.

2. Experience with deocmmi ssioning ' •


About 20 nuclear power plants in the Western world - all of them in the United States and in Europe - have already been retired from service. \ Five of these plants are located in the Conmunity,' namely:

- Marcoule G 1 and Chinon 1, in France

- Heissdampfreaktor (HDR) and Kernkraftwerk Niederaichbach, in Germany

- Dounreay Fast Reactor, in the United Kingdom.

Decommissioning of most retired plants has not yet proceeded beyond Stage I. Five plants have been decommissioned further, namely: HNPF, BONUS, ERR (all in the USA), CNL (Switzerland) and HDR (Germany). *

These decommissioning operations have complied with the regulations for protection of the personnel- and the general public; no particular incident has been reported. They have yielded valuable experience as regards decommissioning techniques and cost. However, this experience is not directly applicable to future decommissioning of nuclear power plants, and of large commercial plants in particular, for the following reasons:

- the reactors were of one-off types, not used in commercial plants;

- tb<sy were relatively small; ■ ' - .

- they had been operated for relatively short periods, and

consequently radioactivity inventories were small; .

Relevant experience has also been obtained from the decommissioning of major nuclear power plant components. Within the Community the ' dismantling and cutting cf the thermal shields of the Trino Vercellese and the Chooz pressurized water reactors deserve particular mention in this respect.

Decommissoning operations at research reactors and fuel cycle plants have also yielded experience which is of considerable value in the decommissioning of nuclear power plants. Major operations performed in the member countries are:

- total dismantling of the LeBouchet uranium fabrication plant

C France) '

- total dismantling of a small prototype reprocessing plant at Fontenay-aux-Rcses (France)

- extensive decontamination operations at reprocessing plants at Mol (Belgium), Dounresy (UK) and Trisaia (Italy).

The available experience has been taken into account and carefully extrapolated in the studies of decommissioning of commercial plants, ' which form the subject of Chapter 3. .

11.

3. Decommissioning studies


12.

3.1 Light water reactors


Light water reactors are of particular interest since they constitute the major part of the nuclear generating capacity installed and under construction and because their proportion is forecast to increase over the coming decades. The decommissioning problems posed by pressurized water

reactors, which account for about 80 X of the Light water reactors in the Community and are taken as a reference here 1 2, and by boiling water r'eac-^ tors do not differ fundamentally.

Radioactivity _ -

■ . ■ ■ . . ' - ‘ ’ . ' / "• . • \

The radioactivity inventory after 40 years of operation and one year after shutdown is illustrated by the following data (orders of magnitude):

Components (material) \Weight

t
Activity

Ci
Reactor vessel internals (stainless steel)—\

OC

o
'io7
Reactor vessel (mild steel, cladding ■

, stainless steel)
■ 5805000 .
Biological shield (concrete, reinforcement . ; mild steel) ,430700 v
• - ■ ■ ) • • , • .

Systems contaminated only (stainless steel)
6000'3000

The total activity inventory is lower by a factor cf about 1000 than that V. shortly after shutdown, this being due to the removal'of fuel and to the decay of short-lived nuclides. The bulk of this activity is represented by a few reactor internals surrounding the core, with maximum specific activities of about 2 Ci/g. ■

More important than these total activities are those of specific 2 nuclides. There are no significant amounts of the radiotoxic long-lived

/ ■ 4 ■ , ■ . . . ; '

alpha emitters. Cobalt-60, because of its penetrating type of radiation, determines the exposure of personnel during decommissioning works and there-■ i?>re ■ dictates the degree of shielding and remote operation required.

13.

Its decay - Its half-life being five years - is the principal reason


for delaying dismantling. Because of their long and very long half-lives*

. • *

nick^l-63 and nickel-59 will have a major influence on the choice of thv. final storage or disposal mode of steel components.

Sven though nickel-59.and nickel-63 may be present in significant quantities for long periods, their potential biological hazard must be kept In perspective, considering the low level' and penetration capability of the radiation.

Decommissioning alternatives^ • ,

According to the studies it would be feasible but not optimal with respect to both health protection and costs^ to undertake complete dismantling and removal, of the plants immediately after shutdown ("Prompt ’ Stage 3"). On the other hand it would not^be practical to delay Stage 3 ' until it was reached merely by the decay or the radionuclides. The principal reasons for proceeding to Stage 3 appear to be the degradation of contamination barriers; the surveillance costs during lower Stages anc, possibly, national licensing requirements. The economic value of the land area recovered would be comparatively insignificant. A nuclear site may be of high value to the utility, but it would generally be possible

to build a new plant without removing the reactor building of the old ,

■ • . . • • ,

one, since this building usually occupies only a small part of the site area. • •

14.

The decision to start on Stage 2, as against Stage 1, will depend


* ... ' i ' . j . -

to a large extent on the national licensing requirements. Recovery of ; site area and esthetic reasons will not be an incentive, since underground

entombment appears impractical and substantial overground structures or even the whole containment building, as envisaged In the United States,v will remain in place during Stage 2. _ .

, • ' ’ . ' ' ’ * ' I* •’ • , *

■' ■ : ' • • .• i ; ■ t •

_Decnmrn1_s_si_DnJ_n2 .costs - -

Decommissioning costs accrue from decommissioning works at the plant, from management and disposal of the wastes produced and, until Stage 3 is reached,, from surveillance and maintenance of the plant. The mode of waste disposal is decisive of disposal costs and may also condition preceding operations and their costs. As the disposal mode is unknown as yet, cost estimates have been based on assumed disposal modes and therefore are to a certain degree hypothetical. The following costs have been estimated recently in an American (A) and in a European <E) studyatlin millions of 1975 US SJ, including removal of non-nuclear buildings):

. *

Decomissioning alternatives " ■ ■
Study
A ;E
, Prompt Stage 3 ' '2779 '
■ • ' ('-1') ■ ^ >

Delayed Stage 3 v after Stage 1 ,
236A •"
- after Stage 2
25m '

(l) Delay after shutdown: 108 years for A, AO years for E; no ,, permanent security force during Stage 1. .

;; ’■ ' %> • •• •" * ' . • , : ■ . . • *- * * i

, These costs range from about A to 13 % of plant capital costs In : ,1975. The difference between the two estimates is to a large extent due1 to the different wasfe disposal modes assumed, which are virtually opposite extremes as regards their inpact on costs. Study A is based on the financial and technical conditions in force at commercial surface burial grounds but assumes the radioactivity limit to be strongly increased, ffhis certainly unrealistic assunption affects only the Prompt Stage 3 alternative). St'udy E is based on the conditions in force at an experimental' geological disposal facility, which require fn paeticular that all wastes are packed in small ' units. >

____ ■ ' * ' . x*. t' t

y A* AIf//NESP_OO9SR; STUDY E: EUR 5728 d ' • . '

Moreover, these costs are not discounted. However, comparison of costs arising at different points in time inevitably involves discounting and not discounting amounts merely to using a discount rate of zero. Discount rates may be chosen on the basis of anticipated interest and inflation rates, of utility practices or of macro-economic considerations. Thus no specific rate can be proposed here, but the preponderant influence of discounting, even with rates as.low as 1 % per year, has to be stressed. This influence tends to reduce the. ratio of decorwnssionir.g to capital costs, the reduction being the greater the longer Stage 3 is delayed and permits .' sinking-funds to grow. •

The current costs during Stages 1 and 2 would be lower than assumed ' in the studies if the decommissioned plant shared the site with at least one operating plant, which will be the most frequent case in the foreseeable future. On the other hand, a permanent security force, which might be required for a single plant in Stage 1, would result in an additional cost. Constant annual maintenance costs, excluding major works, have been assumed but it is recognized that this may be unrealistic, in particular for longer periods of delay. Maintenance costs are expected to increase ' at long term, as excessive degradation of the plant is to be avoided, and this might be a reason to proceed to Stage 3 earlier. This aspect requires further study.

_0 cjc (£ a_t i_ona l_exp_o sun?

Occipational radietion exposure is seen to be the main safety concern in decommissioning. Not only have the individual dose limits to be complied with, but also the total radiation dose should be kept within acceptable limits. Besides the use of shielding, remote operation and enclosures with controlled ventilation, careful planning of the successive decommissioning pperations is essential. Total occipational doses estimated in the already mentioned study A, are 630 man-rem for Prompt Stage 3 and about 450 man-rem

for Stage 1 or 2 and Delayed Stage 3 <108 years after shutdown). It has to be mentioned'that substantially higher doses have been estimated by others.

3.2. Gas-cooled reactors . • ’ , ■ ' • , ' :

Gas graphite reactors will probably form the bulk of the nuclear power plants which will become redundant by the end of this century.

' • ’ . • . ’ . _ • ’ • ’ ' . ' ^ g -i

. ' ' ■ ■ . . • ' r '

Important differences in the radioactivity inventory compared with N light water reactors are the lower specific activities but larger volumes, the preponderance of mild steel over stainless steel and the large amounts of graphite, which, however, are present as easily manageable pieces. The following amounts of materials have been indicated for the pressure vessel and the pressure vessel internals.of a typical commercial Magnox reactor (capacity: 250 Mwe): 2500 tpnnes of mild steel, 100 tonnes of stainless steel and 2500 tonnes of graphite. As regards the biological shield concrete, only its inner layer is activated. The thickness of this layer will be about 1.5m two years after shutdown and will decrease with time as the result of radioactive decay. Nevertheless this concrete would present the major disposal problem in terms of moss. Heat exchangers would by their size and by the tube surface area and geometry pose a major decontamination problem. - . . .

. The study of the decommissioning of a representative commercial Magnox reactor is still in progress, but a detailed technical study on the Wind-scale Advanced Gas-cooled Reactor-CW.A.G.R.), has been completed and it is likely that its conclusions will in principle be applicable also to Magnox reactors. The W.A.G.R. study is based in one case on a progressive procedure, considering Sta^e 1 as an interim phase. Stage 2 as a storage situationof unspecified duration and Stage 3 as the ideal ultimate objective* The al-tehnative case is the progression from reactor closure to Stage 3 as a continuing operation. In particular, it is concluded that a satisfactory long

term Stage 2 condition can be established and that there is no technical obstacle to proceeding directly to a Stage 3 condition. The conception of Stage 2 differs from that envisaged in the United States for pressurized water reactors in the dismantling of the containment building and the heat exchangers, resulting in a considerable reduction of the occupied area and the visual impact. For commercial steel pressure vessel Magnox reactors, irrespective of output capacity, the remaining structures would be cylinders with a diameter of about 30 metres and a height above ground of 18-30 metres.

A detailed decommissioning study has been performed on Chinon 1, a 70 MWe gas graphite prototype plant> which was retired from service for economic reasons in 1973, after having operated for 10 years with an average load factor of about 50 %. From activity measurements carried out on samples, the activity of the graphite moderator (1050 tonnes) at the end of 1975 has been estimated as 3000 Ci of cobalt-60, 1200 Ci of tritium, 300 Ci of carbon-14 and 0.5 Ci of plutonium-239 and -240. Measurements inside the fuel channels have shown dose rates in the order of 10 rem/h from the graphite reaching a maximum of 400 rem/h near the core support steel plate. The activated steel components amount to about 1500 tonnes. First measurements indicated that the biological shield concrete is not activated.

The Chinon 1 study compares the direct approach of Stages 1, 2 and 3. Stage 2 was assumed to embrace the reactor vessel and the heat exchangers within a concrete enclosure and to involve dismantling other contaminated systems, storing the parts within sealed premises in the containment sphere. The conclusion was that this condition would not be safer than Stage 1 and that it would complicate proceeding to Stage 3 subsequently. Stage 3 was studied in detail, including the conceptual design of the required remotely operated equipment.

15.

On the basis of this study it was decided to convert the plant into a nuclear museum. This conception, which in particular allows the public


access to part of the containment sphere, is planned to be achieved in 1978 or 1979. The option to proceed to Stage 3, 3C years later, remains open.

16.

3.3. Decommissioning subsequent to a major accident


The studies considered in the foregoing sections (3.1, 3.2) are based on plants which are .retired from service in a normal condition. Major plant accidents, resulting in a wide spread of heavy contamination within the containment building, would pose special decommissioning problems and even complicate routine operations, such as the discharge and the removal of the. fuel. Whereas such accidents are taken into account in the plant design, their impact on decommissioning is not well known. First studies, which are in progress, have shown the complex nature of this problem. 1

• ' ' m ' ' ' ' - . ' .

4. Decommissioning techniques .

4.1. Decontamination ' .

The purpose of decontamination in decommissioning will in most cases be to facilitate the dismantling and further treatment of components, by reduction of the radiation level and removal of loose contamination. Another possible objective is 'complete decontamination', i.e. decontamination to a level below the limit for unrestricted release of material, in order, to reduce the volume of radioactive waste. The benefits of decontamination have to be weighed against operational risks, arisings of consequential waste and costs. Thus different opinions exist as to what is a reason- -able decontamination effort. This question merits further study, but it cannot be answered without a better knowledge of the technical options.

The only proven decontamination techniques are those which are currently used in operating reactors and which may be classified as follows:

■ - i'' ’ *

■ * ' • ..

“ amjon, applied within closed systems of the plant

and using chemical agents;

- Jmnersion ctecojitamination, applied to dismantled component and ■ using chemical agents, generally .combined with mechanical means such as brushing or ultrasonic waves; „

“ decontamination, applied to systems locally through openings, or to dismantled components in special cells, or even to the surfaces of premises, using jets of vapour or liquid or of a mixture of liquid and grinding particles.

Experience with these techniques is substantial but difficult to interpret. Achieved decontamination factors vary over a wide range, depending on the particular conditions in a way which is not yet well understood.

These proven techniques have been developed for application to components to be serviced or repaired, that is to say, subject to the condition of preserving component integrity. Whereas these techniques are also user ‘ fully employed in dc-commi ssitiming, more aggressive methods, resulting in more effective decontamination, would be desirable. These could be variants the proven techniques, i.e., system and immersion decontamination using mors aggressive chemical agents or jet decontamination using higher pres- 7 sure or more abrasive grinding particles, etc., but also basically new techniques. ,

System decontamination offers the advantage pf preceding the opening up and dismantling of the system,thus reducing personnel exposure. It reaches a large surface at a time, but cannot be applied selectively to local peaks of contamination. It is also less effective in crevices and dead ends of a system, where contamination often concentrates. Consequently, system decontamination will as a general rule not result in complete decontamination.

The large volume of certain systems, such as the primary codling circuit, and the need for several decontamination and flushing steps give jise to very large quantities of radioactive tiquid, which may pose problems of in-, terim storage and of treatment."Moreover, differential attack on the various materials of a system and the spread of contamination to initially clean

regions are aspects which have to be considered.

Immersion decontamination can use existing equipment for small components, but the corrosive attack of the-tanks must-be considered, if more aggressive chemical reagents are employed. Major components would pose problems of space, equipment end of volume of liquid produced.

, ‘ ' - . i . i ■

The folowing.new techniques have been proposed:

- Decontamination by chemical agents applied as a surface layer, i.e.,

pastes and fcoiten salts. Laboratory experiments have shown promising results, indicating high efficiency and low volume of consequential waste. - ' ■

- Electrolytical decontamination, using similar processes to the electropolishing known in the non-nuclear industry. :

- Decontamination by explosive methods. Preliminary experiments have demonstrated that the oxide film, which incorporates the contamination

of steel components, can be spalled off from the base metal. With this '

.. technique the volume of consequential waste would be very small. ■

4.2. Pismantling , , ' '

_Dijsman_t linjj _cf_sjt eel_cor^cnents

The reactor vessel and the reactor vessel internals pose the most difficult dismantling problems, because of the high radiation, level, remote operation is required. The more active vessel internals of light water reactors should preferably be cut under water, the water providing shielding and reducing aerosol production. Certain components have large wall-thick- . nesses, ranging up to 500 mm (reactor vessel flange of pressurised water reactors). . : ••

' . . • " , . . . . ; ’

Mechanical- techniques such as mill cutting and sawing can be carried out under water, but they 're time-consuming and require heavy.supports.

With thermal techniques special attention has to be paid to the confinement of aerosols. Plasma arc cutting, which can be carried out under water.

appears attractive. At the present time it can be employed'to uall"thick-

nesses up tc about 170 mm, but has development potential up to 500 mm.

17.

Another promising technique is oxy propane cutting. Electro-melt separation


can be employed for large wal l“thicknesses but has the disadvantage of strong . . ' * aerosol production.

Concerning’ the dismantling of pipework, the removal of thermal insulation may pose special problems. Moreover, no' adequate technique is currently available for cutting large-diameter large wall-thickness pipework, such as that employed in the primary circuit of pressurized water reactors. Cutting of pipes by explosive methods constitutes a new technique which should be developed. Experiments carried out cn pipes of moderate size have shown that it is possible with explosive methods to disconnect a pipe and to close its ends in a single operation. ■ i

Dijsmantljn£ of concrete structures ■’7

The concrete structure which usually poses the main dismantling problem is the biological shielding. Special problems due to stored energy may arise with certain prestressed concrete pressure vessels which are employed in some gas graphite reactors. ' . .

There are several proven techniques for dismantling concrete. In the explosive technique charges placed in holes loosen up the whole structure or break it up into layers. This method is relatively expensive and timeconsuming. In the thermal lance technique,: holes closely put in a line are burnt into the concrete by a jet of oxygen, to which iron is supplied as fuel. Dismantling by this method is relatively quick, but is accompanied by intensive smoke formation,. Additionally sawing, hydraulic or pneumatic wedges, or high pressure water jets may be used. *

■ ' 1 . .

These proven techniques will require further development and adaptation,

to perform the more difficult tasks of future dismantling operations.

18.

. I


Other techniques to be considered are hydraulic cracking, oxy-arc cutting and successive boring and cracking by freezing* .

4.3. Equipment for remote operations .

Remote operations such as dismantling, decontamination, conditioning and packing require special equipment to hold and move tools, measuring instruments, telecameras and the parts to be treated. Such equipment may be designed ad hoc for a special situation or for multiple use. It belongs to a technology which is already employed in reactors and hot cells but has to be scaled up and further developed for clecommi ssioning operations.

19.

4.4. Management and storage of wastes from docommissioning '


Conditioning, packaging; transport and storage or disposal constitute, a series of operations which have to be optimized as a whole, taking as a basis the specific characteristics of the type of waste considered. The process of evolving the optimal management concepts for wastes from decommissioning is still in a preliminary phase. '

The waste arising from dismantling of major activated components is characterized by the large initial dimensions and by"the fact that the bulk of radioactivity is incorporated in the base metal. One leading idea for the management of this waste‘would be to limit the cutting to the extent necessary for transport, thus minimizing work under radiation and the spread of radioactive material. Accordingly, large transport containers should be developed for certain components and the storage facilities should be designed for acceptance of large units. . 1

For contaminated pipework a treatment reducing the storage volume appears desirable. Press compaction, cryogenic cracking and smelting have been proposed as techniques. The feasibility of such a treatment should be studied, including the question, whether the operation should be carried out on the site of the nuclear'power plant or in a central facility.

- As regards radioactive an inexpensive method fop the


concrete, waste, it would-be c, long tern immobilization cf'


esir'abtc to have' the ■'rodioriufcl ides.


Controlled burning has been proposed for the graphite arising in the decommissioning of gas graphite reactors and advanced gas cooled reactors.

In order to decide whether this method is appropriate, it is. necessary to consider not only its local radiological impact, but also the long-term consequences, through the contribution to the worldwide background radio-, tion, of releasing to the atmosphere considerable amounts of the long-lived radionuclide carbon-14.

Consequential wastes nced.no special consideration here, since they can be managed appropriately by the methods which are currently employed for wastes arising at operating nuclear power'plants.

The following methods have been envisaged by certain countries for fi-nol storage or disposal of different types'of waste arising from decommissioning surface storage, storage in a former mine, disposal in drilled deep holes and sea dumping.

5. - Estimation of the quantities of radioactive wastes from , ■ '

deconni ssioning

5.1. General considerations' ' ■ • ■

The following information is required to estimate the arisings of : radioactive wastes from the* decommissioning of nuclear power plants:

a) schedule of retirement of the plants from service;

b) inventory of the radioactive components, systems and structures ;

of the plants and estimate of associated radionuclides; ..... .. . .

20.

c) schedule of decommissioning works and in particular of


. dismantling; . . . . ’

c!) extent to which the original volume and radioactivity of tlie

‘ ' '
^ materials concerned are changed by decontamination, conditioning,

.. k . . -

overpacking, etc., and production of consequential wastes.

- la -

-The result of a first tentative approach to item a) is given in ' point 5.2. below.

As regards item b), because of the variety of existing nuclear power stations, most of them are to be considered individually. Some information . is already available, but a great deal of work is still needed before a complete survey of radioactivity inventories can be established.

21.

For the evaluation of items, c) and d?, reference strategies have to be evolved; this is to be considered as a long-term task. '


5.2. Retirement of nuclear power plants from service , 1

, • I . - * • • • - ' • ,

.It is premature to make firm estimates on the schedule of retirement of nuclear power plants from service, since the operational life is uncertain within a wide range. The following table illustrates a possible pattern. . 1 ■- • ' 5 , ; 1 It takes into account the. plants which are currently in operation or under

construction in the Community and is based.on an assumed operational life of 30 years, except for certain prototype plants, for which specific shorter., periods have been adopted. . •' ... .

22.

1 . '

Reactor type ~Reactorsretired overperiod:
1981-19901991-2CG02001-2010
Gas graphite and advanced . -■

gas-cooled reactors . .. i .
11 r20 14
Light water reactors.x 3737
Other types ' L ' '' 2.' 2' 4
Total ' ,'162955 !

23.

6. . Guiding principles ' ' '


Guiding principles concerning decommissioning con be formulated only , in a very general way as regards the immediate future and can only be developed in greater detail as a long-term process, Moreover, consideration at Community level must take into account the different conditions prevailing in the Member States, such as reactor types employed, territorial conditions and urgency of decommissioning. ,

• . ' Community efforts in this field should not duplicate or hamper the measures undertaken on a world scale by the International Atomic Energy Agency, but it should be recognized, that the Community could bring its point of view to bear with greater weight in this wiaer framework if it had clear conceptions substantiated by appropriate studies. 1 '

' " • - ‘ ' . / ■■ ’ . . • • • -

24.

6.1. Guiding principles in the design and operation of nuclear power


pl^rcfs with a view to simplifying decommissioning ^

25.

Studies have indicated, that as regards decommissioning modern nuclear


! ' ■ I ■

power plants pose- no fundamental difficulties which would require basic changes in design. Improvements with a view to facilitating decommissioning have been proposed and appear possible, concerning features such as the arrangement, design an^ materials of plant components. ■ . ,

Features which are increasingly introduced into modern nuclear power plants, in order to facilitate maintenance and repair during the operation period, will ultimately also facilitate decommissioning.

26.

6.2. Guiding principles in the decommissioning of nuclear power plants


Decommissioning operations are subject to general nuclear regulations, but no specific detailed guidelines for decommissioning exist in the Member States as yet. For instance, permissible radiation limits for the personnel and the general public are laid down in the general regulations, but there

aro no criteria for the unrestricted release of equipment and sites. Such matters have boon settled in past decommissioning operations on s case-by" case basis. In this context mention should be made of the present efforts by the International Atomic Energy Agency.

PART II: PROGRAMME PROPOSAL

1. Underlying considerations • _ ■ • •

Major advances in concepts and techniques will be required to decommission the nuclear power plants in the best way, with respect to both health protection and economy. The solutions adopted may influence the development of nuclear power through their economic impact and through the reception they meet with among the public.

As the number of plants to be decommissioned will increase at only a slow pace during the coming decades and, moreover, dismantling and removal of the plants, if necessary, may be postpones for considerable periods after their withdrawal from service, if might be concluded that no sub- ■ stantial effort to solve the problems of decommissioning is called for at the present time. This conclusion would, however, be a dangerous mistake, for the following reasons: . .

- Features which facilitate decommissioning should be developed and increasingly introduced in the design of new plants.

- The task of identifying, developing and.imp lamenting the optimum solutions will take a long time. The technical developments will be conditioned by the legal and administrative framework, and in particular by the criteria for release or for acceptance at central depositories of the- wastes.

The industry therefore need3 guidance on these questions at an early stage On the other hand, better knowledge of the possible technical options is needed in order to evolve the legal and administrative framework. ■

- better knowledge of decommissioning costs will enable utilities to

27.

accumulate provisions for decommissioning in accordance with national requirements. •


- Decommissioning operations may be urgently required in particular situations, for instance after an incident.

- It is becoming*increasingly important, in order to secure public

acceptance of new plants, to have elaborated and weLl-founded concepts for the 'back ends' of nuclear energy generation, even if definitive solutions are not yet really needed. One could go so far as to consider dismantling and removing a olant earlier than would otherwise be appro- .

28.

priate, in order to demonstrate the feasibility of a decommissioning concept. '


The Commission therefore holds the view that in addition to the research activities of the Joint Research Centre an indirect action joining forces at Community ' level, in the form of exchanging information and sharing work, could save money and time. Moreover, a Community approach could favourable influence acceptance by the public of the solutions adopted by the Member States, whatever their differences to suit the orrticular features of the nuclear power .

plants and other national conditions. Work already going on in a member country could be pursued under the common programme, if the countryagrees ?ncj -jf the work is of interest to the Community. The public service nature of this work and the secondary importance of competing commercial x

interests at stake will facilitate a Community approach. ,

• ■ . . . . .

2. General features of the proposed programme ■ ■

29.

The programme, which is proposed to cover a period of five years beginning 1 July 1978, must be regarded as the first stage of a longer-term •


effort. It consists of a series of studies and experimental projects aimed at evolving the most appropriate solutions, with respect to both health protection and economy, for the decommissioning of nuclear power plants. ,

These studies and projects will be financed largely by the Commission and coordinated by it with the help of an Advisory Committee on Programme Management comprising representatives of the Member States and Commission .

officials. This committee will have to meet as soon as this programme is , •

' . i ■ . ‘ _ .

approved. The work will bo carried out by qualified public or private " agencies in the Member States. ' ‘ • ' - • ' v , .

In order to avoid duplication, the programme takes into account the' relevant activities of the international organisations. On the other hand, the scope of the programme has been strictly delimited to prelude ovorlsn-pino with the Community programme op radioactive waste management and storage. In particular it takes into account activities dealing with the decontamination of reactor components being carried out at JPC within the frame of their multiannual programme 1977-1980 and will be closely coordinated with these activities.

' • V

30.

The programme may be submitted for review at the end of two years, to reorientate or amplify.it, whore necessary, in the light of the results obtained. -


3. hosearch and development actions ,

The proposed actions, which arc described in annex II, concern'the following subjects : ' . ' ,

Action .MO 1 : Long tern integrity of buildings and systems.

Action l'° 2 : Do contamination for decommissioning, ournoses. ■

Action 3 : Dismantling techniques. -

Action N° 4 : Treatment of specific waste materials : steel, concrete anc!

graphite. ' '

Action N° 5 : Large transport containers for radioactive waste produced in the dismantling of nuclear power olants.

Action N° 6 : Estimation of the quantities of radioactive wastes arising . from decommissioning of nuclear power plants in the Community

Action *!0 7 : Influence of nuclear power plant design features on

31.

. decommissioning. •


' . • . .

32.

These proposals have been formulated on the basis of the analysis of earlier studies and experience, which is contained in Part I of this document. '


Tn ?ddition to these proposals it is envisaged that the Community participates in a large-scale operation, carried out in the context of decommissioning of a nuclear power plant or of a major component of such a plant and involving the demonstration of new techniques or the extension of proven techniques to a wirier range of conditions, such as size and radiation level of components. As no specific action can be proposed at present, the subject is mentioned here only for the record, but a proposal should, if possible, be submitted for the revision of the programme.

The Community's financial contribution would depend on the general interest jof the information-expected to be obtained from the proposed action. .

4. Identification of guiding principles .

This activity relates to :

- Guiding principles in the riesign. and operation of nuclear power plants with a view to simplifying their subsequent decommissioning.

- Guiding principles in the decommissioning of nuclear power plants.

Guiding principles need to be progressively evolved in order to plan the research and development actions efficiently; conversely, the results of the actions may influence the shaping of the guiding principles. In view of this interdependence the programme includes provision for the progressive evolvement of guiding principles.

The intention is that rough material for guiding principles

■ . • “\ . e • ■

prepared in the Member States should be assembled and analysed, and an assessment then made of the scope for approximation and joint development. At a later stage of the programme it will be endeavoured to frame proposals for common guiding principles. >

The Commission should also have a limited budget for this action so that it could have the necessary analyses performed under study contracts.

5. Breakdown of proposed funding .

Costs over five years in millions cf European units cf account (EUA) :

33.

V , ’


Item .Costs
Contribution to research and development actions :
Action h’° 1 •/

0.3
- Action N° 2 \ .
13. 4
Action i':0 3 _1.1
Action A0.6 •
Action f;° 50.2
■ Action i110 6 .0.4
Action N° 7. 0.6
Subtotal actions 1 to 74.6
Identification of guiding principles0.2
Staff 31.51
Meetings. ; - .0.27
Total6.38

ANNEX I

SUPPORTING INFORMATION TO PART I

34.

to 2. Experience with decommissioning


The nuclear power plants which have already been retired from service are listed in Table 1. Further information on nuclear power plants which have been decommissioned beyond, Stage 1 is given in Table-2.

to 3.1. Light water reactors ■ . . , .

Table 3 gives information concerning radionuclides of significance as regards activation of steels. Table 4 gives sipplementary information concerning the cost data. ' • ,

35.

to 5.2. Retirement of nuclear power plants from service


The nuclear power plants taken into account in the summary table under point 5.2. of Part I are listed in Table 5. 1

to 6.1. Guiding principles in the design and operation of nuclear power plants‘with a view to simplifying decommissioning . .

The following design features have been recommended in the frame of the International Atomic Energy Agency (document IAEA-179):

_Arrang_ement _of_comperie_nt_s _anc structures .

, Components and structures should be so arranged that: •

- The site can utlimately be developed to its maximum potential despite the

eventual existence of decommissioned structures;

' . - .

- There is sufficient space around them to permit access with transporting equipment, shielding or tools;

- Suitable cells or cabins can be erected around them to restrict the dis-perison of radioactive material during their dismantling and, if necessary, to permit operations at a lower pressure than in the surrounding atmosphere;

- They ban be removed in one piece through adjoining rooms or the roof,- ■

using olant or external lifting device- ’f ~oc-'--- . •

- 2 - '

_CjDnst_ructiqn of _co_ri[=>j2P^n_Ls_~ilcL.sJE.rJtic-£.HIle_®. " '

Components and structures should be so designed that:

- The contaminated or activated components can be cut off;

Example: Detachable concrete layers on the biological shield;

•* Their activation level is reduced;

36.

Example: Distance between the steel reinforcement of the concrete and


i * •

the neutron flux zone; .

-The components and structures can be broken down into parts which arc relatively light/ small and suitably shaped for transportation;

- Suitable passages and openings are provided for removing them from the

containment or reactor building; ’

- As many components as possible are replaceable;

- ilaterials are selected to reduce the formation of nuclides with a long

half-life. . .

J)e_cont_amjnjiti_on. £C£vi.s_ions : ,

To simplify the decontamination of components/ pipe systems and rooms/ the following provisions should be made; . .

- The spreading of active corrosion products or deposits during operation

or decommissioning should be limited by for example/ the incorporation of drain points, devices for flushing the piping systems and traps in pipe systems; " - . ,

- Facilities for the decontamination of components and rooms, including

means of introducing and draining decontamination solution. , •

j[\djni£ti_str a_ti_ve__meascir.es , ’ ' '

’■ . A reliable documentation system should be established and used

to record all changes in the design and materials of the plant during its operation. .

37.

Table 1. Nuclear power plants retired from service

. CountryPlant*

Type
Capacity MW aOperating ! period
France(iarcoule G1GGR41956 r 1966 '
If .Chinon 1GGR701963 * 1973
Germany. HDR GrosswelzheimBWR25,1970 - 1972
IIKKN NiederaichbachiiWR1001974 - 1974
United - KingdomDFR Dounreay. FSR t151963 - 1977
SwitzerlandCNL LucensHWR8196tt - 1969
USAVallecitos IfVESRBWR51957 - 1963 '
.Elk River ReactorBWR221964 - 1968
IIHallam HNPFSGR ’751962 - 1964 .
IfBONUSBWR16.51962 - 1968 ;
HVatlecitos VBWRDWR101957 - 1963
IISanta SusanaSGR7.51958 - 1966
‘ IfPi qua OMROMR11.41963 - 1966
Carolinas CVTRPWR17’1963 - 1967
II ;Enrico FermiFUR611966 -1971
IIPathfinderBWR621962 - 1967
If ’Saxton-.PWR4.21962 - 1972
ifPeach BottomHTR40.1966 - 1974 .

BWR = boiling water reactor GGR ' gas graphite reactor FBR s fest breeder reactor HTR * high temperature reactor HWR = heavy water reactor OMR = organic moderated reactor PWR * pressurized water reactor SGR = sodium graphite reactor

38.

Tsble 2. Plants which have been decommissioned beyond Stage 1


PlantHNPF (Hallam Nuclear Tower facility)BONUS (Boiling Nuclear Superheater Reactor)CNL (Centrale "nucleaire Lucens)ERR (Elk River

Reactor)^
CountryUSA %CZ

CO
SwitzerlandUSA ,
Reactor typegraphite moderated sodium cooled .boiling water nuclear superheatingheavy water moderated, gas cooledboiling water (fossil superheating)
Capacity (fide)7516.5822
Operating period1962-19641962-1968196o-19691964"1966 .
Activity* ^ .

inventory (Ci)’
3J10550.0005U09000
Cor.c it ion reachedUnderground entombment; top planted and accessible without restrictionEntombment in biological shield; plant converted tc museumLow active parts (total '1.5 Ci) entombed; other parts packed and stored on site; reactor caverns accessible withoui restrictionStage 3 completed in 1974 . •
Decommissioning

CO St

* - - --- - —----------
4.2 millions US £not availablenot available5.7 millions 'J3 £
* HNPF: at time of entombment closure; others: at start of decommissioning
Table 3. Radionuclides of significance as regards activation of steels used 1>n light water reactors '
Radionuclide .Iron-55Cobalt-60Nickel-63Nickel-59
Half-life, years. 2.45.29280,000
Radiation , .gamma. X-raygamma, beta .. betagamma. X-ray
■ -_■ .
Mother elementIron' CobaltNickel
Content ,(%) of mother element ini■ -
- stainless steel (1)
70traces10
- carbon steel (2)
97traces: o
00



o

1

in



Components: Reactor vessel internals, reactor vessel caldding

Component: Reactor vessel \

39.

Table 4: Cost estimates for decommissioning of light water reactors


(1200 HWe plants; operating time: 4C years)

Costs in millions of 1975 US8 (1)
Study 'EA'
Reference .EUR 5728 ;' AIF/NESP-U09SR
Reactor’ PWRBWR"• PWRBUR
Discounting(2)no(2)nonono
Prompt Stage 3do. 478. C
33.495.426.931.2
Delayed Stage 3 - after Stage 1
- Stage 1
4.54.64.54.62.32.4
- Interim costs (3) -case I
0.30.70.30.79.59.2
- -case i:
(4)(4)(4)(4)18.017.4
- Stage 3 (5)
12.259.013.163.311.011.7
- Total -case I
17.064.317.968.622.623.3
-case I!(4)(4)(4)(4)51.331.5
Delayed Stage 3 - after Stago 2
- Stage 2
7.47.6
- Interim costs (3)
(4)• 6.3
6.0
- Stage 3 (5) .
. •10.612.2
- Total -

_
24.525.8

Data from study E converted with the rato'jl DM = 0.4 US2

Discounted to shutdown date at an annual rate of 3.7 % (This rate

results from assumed annual rates of 12 7. for interest and of 8 % for inflation) >

Based on following "annual costs of maintenance and surveillance:

Study .E .A
After Stage 1 - case I: no security force

- case II: with security force

After Stage 2
0.C19

(4)

:
0.068 . 0.167

0.058'

(4) Alternative not considered ' ' '

Delayed Stage 3 40 years (study t)„ IQS years (study A, PWR)

and 104 years (study A, B'lR) after shutdown (The delay periods assumed in study A were estimated to permit manual - as opposed to remotely operated - dismantling). ‘

Table 5: Nuclear power plants built or under construction , in the European Community • • .
PlantCountryTypeCepccity

l iU©
Start of operationYear or

assumed period of closure
Marcoule G1 'FGGRA19561968
HDR Grosswelzh^imDBLR2519701972
Chinon 1FGGR, 7019631973
KKN NiederaichbachDHWR10019741974
DFR DounreayUKFUR1519631977
BR-3 hoi :BPUR101966
MZFR KarlsruheDHWR511966
(Otto Hahn .DPUR196b
El-A Monts ci'ArreFHUR7019671981-1990
VAK KahlDBUR151961
UAGR WindscaleUKAGR321963
Marcoule G2FGGRAO1959
Marcoule G3 -FGGRAO1960
CalcJerhallUKGGRA X 501956-1959
Chapel crossUK ‘GGRA X 501959-1960
BerkeleyUKGGR2 X 13b1961
BradwellUKGGR2 X 1501961
LatinaIGGR210 :1964
Hunterston AUKGGR2 X 1501964
GariglianoI ■BUR. 1601964
Trino VercelleseIPUR2571965
Chinon 2FGGR20019651991-2000
Mink ley Point A•UKGGR2 X 2501965
TrawnsfynyddUKGGR2 X 2501965
Dungeness AUKGGR2 X 2751965 •
Chinon 3FGGRAbO1966' ' .
Sizewell AUK -GGR2 X 2901966
KR3 GundremmingenDPWR2371966
. SENA ChoozFPUR3051967 1
AVR JDlich0 ■HTR131967
Oldbury AUKGGR2 X 3001967-196b
KUL Lingen ‘DBUR.. 1821968
KWO ObrigheimDPWR3281968
GKN DodewaardNL8WR521968
SGHWR UinfrithUKHUR. 92.1968
St Laurent 1FGGRAbO1969
St Laurent 2FGGR5151971
WylfaUKGGR2 X 5901971
KNK Karlsruhe . - ...DSZR191972
KUW Uurgassen .. DBUR6401972
KKS Stade - •0PWR6301972
Bugey 1FGGR5 AO1972- 2001-2010
BorsseleNLPUR4501973
PhenixFFBR2331973
Table 5: continued
PlantCountryType’ Capacity MWeStart of operationYear or ;

assumed period of closure ,
Biblis ADPUR11461974
Doel 1BPUR3901974- •
Tihange 1BPUR8701975
PFR DounreayUK ___FBR * '230

r ■ -
1975 .1 . . ^
Doel 23PWR3901975• „ ■ .
Bibtis 0. DPUR12401976 '
GKN NeckarwestheimDPWR7751976
KK3 BrunsbuttelDBWR770'1976
Hinley Point £3 -UKAGR2 X 6251976-1977
Hunterston BUKAGR2 X 6251976-1977
Fessenhoim 1,2FPUR2 X 8901977
KKI IsarDBWR87019772UC1-201Q
KKP-1 PhilippsburgDBWR8641977
KKU UnterweserDPUR12301977
Bugcy 2, 3FPUR2 X 9251978
CaorsoIPUR8401978
Bugey 4, 5,FPWR2 X 9051978-1979\
Tricastin 1,2,3,4FPWR4 X 9251979-1980
Gravelin.es 1,2,3,4FPUR4 X 9251979-1.981
KKf GrafenrheinfeldDPWR12291979
Mulhein-K'&r licitDPWR11541979
Dungensss □UKAGR2 X 6001979
Hartlepool >UKAGR2 X 6251979
HeyshamUK 'AGR2 X 6251979
Dampierre 1,2,3,4FPUR4 X 9251979-1981
Doel 3BPUR9001980
Tihange 2 •BPWR9001980 .
KKK KrummelDBIJR12601980
THTR-300 -UentropDHTR3001980
St Laurent D 1,2FPWR2 X 9251981
Le Blayais 1,2FPUR2 X 9251981
KWG GrohndePPUR12941981
KRO U,C GrundremmingenDBUR2 X 12501981-1982after 2010
Chinon B 1,2FPWR2 X 9251981-1982
KBR BrokdorfPPUR12941982
KUS WyhlDPUR12831982
SNF.-300 Kalkar ,DFBR2821962_ , . ' • '
CireneIHUS321982
Paluit 1,2FPUR2 X 13001982
Superph6nixF •FUR1200 -1983
KKP-2 PhilippsburgDPUR12301982
ENEL 6,8 Wontalto• I
BWR2 X 9801983-1984' i
Note: The assumed periods of closure result from the assumption indicated in under point 5.2 of Part I. There are generally no planned dates of closure as yet.

ANNEX II

40.

DESCRIPTION OF PROPOSED RESEARCH


Action N° 1

A!iD DEVELOPiit.i'lT ACTIONS

41.

Long term integrity of builoings and systems


- It has been proposed that the dismantling of nuclear power plants be delayed for periods ranging from several decades to about a hundred years, mainly in order to reduce personnel radiation exposure. Significant degra-.-. detion of the plant, and in particular of the contamination barriers, during this time would pose problems of safety, maintenance costs and, ultimately, dismantling. This aspect, which has not been assessed in most existing decommissioning studies, is among others important for the purpose of estimating what would be a reasonable period of.delaying dismantling. .

* The objective of this action would be to improve the knowledge on degradation and to propose appropriate preventive measures. i

Programme *• ' ■ . > . -

- Estimation of the progress of degradation and of the required maintenance effort to be expected as a function of time for containment buildings, based on a review of available experience with similar buildings.

- study of the internal corrosion of closed contaminated systems due to .

residual amounts of humidity and aggressive agents; development of methods for removing residues of corrosive agents. .

- study of other measures aimed at maintaining plants in a safe condition.

Community contribution; 0.3 million EUA. ' .

. . - 2 -

Action v° 2

Decontamination fcr decommissioning purposes .

I 7

The object of this action/ complementary to those carried out at JRC within the frame of their multianpual programme is to develop and to assess decontamination methods which are specifically suitable for decommissioning purposes. These methods nay apply to closed systems/ to dismantled components/ especially those of lame dimensions/ or to the surfaces cf premises. The methods may be more aggressive than those currently employed at operating reactors. Development should aim in particular at obtaining the following characteristics: high decontamination efficiency; simple and ■■ safe application; unproblematic nature and low volume of consequential waste. Methods which can be applied within the premises of nuclear power . plants and with a minimum cf additional eauipment are of special interest.

Among the methods which seem to deserve development/ the following ones may be mentioned: decontamination by pastes and by molten salts; clectrolytical decontamination; decontamination by explosive methods.

Moreover/ a synoptic study should be performed in order to assess the . reasonable decontamination effort in decommissioning/ taking as a basis typical reference components. This study should in particular identify the components for which 'comolctc decontamination', permitting the unrestricted release of thb treated item/ would be practicable. ;

The special decommissioning problems posed by nuclear power plants which have ha:! a major accident will also be analyzed. The study should . ... be based on a loss of coolant accident which leads to severe contamination of the plant. The study should propose.procedures by which the plant can be brought to a condition/ in which it can be safely handled by normal decommissioning procedures. If necessary/ reasonable modifications of the plant design should be proposed. . ’

42.

Community contribution : 1.4 million FUA


Action N° 3 , ...

43.

Dismantling to rhhiques '


Various dismantling techniques have already been utilized in decommissioning, but would require further development to perform the more difficult tasKS required in the future. In addition, promising now techniques: have been proposed. : ,

Because of the variety of techniques, which can be envisaged, if .!o proposed that a comparative screening study, consioering' several typical di mantling tasks, be carried out in order to assess the possible applications and the relative merits of the different techniques* On this basis, the rr.os promising techniques should be selected and developed further.

The following techniques have, however, already been identified for further development: • : .

- explosive methods, for dismantling both steel piping and concrete struc* tures; .. ,

-thermal techniques for cutting thick walled steel' components. . ;

44.

Community contribution: 1.1 million EUA„


Act^n f10 4

45.

Troatror-t of specific Wdst- materials: steel, concreta end graphite


Large amounts cf radioactive waste consisting of steel will arise at every nuclear power plant which is dismantled. Cryogenic cracking and. .. smelting have been proposed as promising new techniques for the conditioning of such waste. ... ..

: Cryogenic cracking is aimed principally at reducing the storage volume and c-p-oears particularly appropriate for elements such as piping.

' Smelting would nav<? several purposes, i.o.:

- maximum reduction of the storage volume;

46.

-maximum reduction of the- surface which could become accessible to corrosion after disposal; . *


- decontamination by slag removal; .

- incorporation of residual contamination into the base material;

- possibly separation of long-lived radioelements.

The object of the action, where these techniques are concerned, is to carry out feasibility studies, including:

- basic studies on specific aspects, such as the effectiveness of deconta

mination by smelting and the possibility of separating long-lived radioelements; 1 _

•* conceptual studies with a view to arriving at tho principal process ' parameters and conditions of application and to assessing the industrial interest of the techniques in question*

The problems posed by tritieted steel waste will also be studied.

As regards concrete w^ste, a conditioning method should be developed, by which the radioactivity is durably immobilized.

Large amounts of graphite will arise from the decommissioning of gas nrepyit reactors end advanced gas-coo led reactors. The object cf this action is to develop s method for the disposition of this waste, taking into account the global and long term radiological impact of carbon-14 in the atmosphere* in case the graphite would be burnt.

' ** . '

47.

Community contribution: C.6 million EUA


Action M° 5

. ■ ■ ; ■ - j

48.

Large transport container? for radioactive waste produced in the


dismantling of nuclear power plants '

Studies have shown that it is desirable to transport the radioactive waste resulting from dismantling of certain major reactor components in larger units than those currently used for other types of radioactive waste in order to- reduce the required amount of cutting and, consequently, the' personnel radiation exposure and the decommissioning costs. The size and weight of the shipping units should at least be such as to take full advantage of the normal transport facilities: ,

\ ’ ■' t , , ■ • '

Programme 1 ,

- System study aimed at defining th.e types of large transport and/or disposal containers needed, depending on the characteristics of the waste,

- * * . . '

such as radiation level, previous conditioning, etc.

. ■ . - 1 / *

- Conceptual study of large containers, including shielding design and

safety analysis; definition of the test programme required for licensing purposes. :

. • ■ . . • ' t • ' ■ ’ i • ' ■

Community contribution: 0.2 million EUA '

Estimation of the quantities of radioactive wastes arising from___

deconroissioning^of_nuclear power plants in the Community 1

This r.ctitn involves the definition of reference* strategies for decommissioning end is therefore to be considered as a long-term task. Consequent ly, the objective in this five-year programme can only be to arrive at a first tentative approach to the problem. •

49.

Programme


- Survey of data concerning radioactivity inventories after shutdown of nuclear power plants in the member countries; this survey should be comple-

, .mented progressively, taking into account new studies which become ■ . available. ' : , " '

- Assessment of different schemes for decommissioning of plants and conditioning of wastes produced.

- Estimate of the arisings of radioactive wastes to be expected from

decommissioning of the nuclear power plants, starting from some selected decommissioning schemes, in order to arrive at longer-term at a forecast of the wastes arising in the member countries. ^ ’ '

Community contribution: 0.4 million EUA • '

Action Ki0 7

Influence of nuclear power plant desigrr features on decommissioning ■

Tho object of this action would be to identify and develop reasonable improvements in plant design with a view to decommissioning. In order to ■ -perform this tr.sk effectively, while safeguarding the industrial information, the participation of plant constructors would be sought.

50.

Programme- '


- In a first phase, exchange of information and views on the extent to which features facilitating decommissioning are already taken into account and on the possibilities of further improvements; identification of some specific potential improvements-which are suitable for study under this ^c-

51.

tion. . '


- Assessment of these specific improvements from the point of view of their technical feasibility, with due regard to safety and reliability of ope— ration, and of their economic and environmental impact.

- Experimental studies on specific selected subjects (e.g„, detachable

52.

surface layers). a . *


Community contribution; 0.6 million EUA.

53.

PROPOSAL FOR A COUNCIL DECISION ADOPTING A PROGRAMME CONCERNING


54.

6 OF NUCLLHR



THE DECGiiUSSIOr


PLANTS


POWER


55.

The Council of the European Communities


HAVIfiG regard to the Treaty establishing the European Atomic Energy Community, end in particular Article 7 thereof;

HAVING regard to the proposal presented by the Commission after consulting the Scientific and Technical Committee;

HAVING regard to the Opinion of the European Parliament;

HAVING regard to the Opinion of the Economic and Social Committee;

WHEREAS the programme of action of the European Communities on the environment approved by the Council of the European Communities and the representatives of the Governments of the hiember States meeting in the

it '

Council in the Declaration of 17 ;iay 1977 , underlines the need for Community measures on the decommissioning of nuclear power plants and whereas it lays down the content of and procedures for implementing such measures; .

WHEREAS certain parts of nuclear power plants inevitably become radioactive during operation, and whereas it is therefore essential to find effective solutions which are capable of ensuring the safety and protection of both man and his environment against the potential hazards involved in the decommissioning of these plants; s

* OJ No C 139, 13.6.1977, P. 34-35

HAS ADOPTED THIS DECISION..

56.

Article 1


A programme on the research relating to the decommissioning of nuclear newer olant shall be adopted in the form set out in the Annex for a five-year period from 1 July 1978. The Annex forms an integral part of this Decision. ' .

Article 2 ,

The expenditure commitments necessary for the implementation of this programme are estimated at 6.38 millions European units of account (EUA) with a staff of five. ' ,

Article 3 , . .

The programme set-out in the Annex may be submitted for amendment at the end of the second year, in accordance with the appropriate pro^dures.

57.

ANNEX


PROGRAMME

Tho aim of the oroqrammc is the joint development of a system of management,of redundant nuclear power plants and of the radioactive . wastes produced in their dismantling which/ at its various stages, will provide man anc! his environment, with the best protection possible; the programme seeks to promote : ' ’

A. °escarch and development actions concerning tho following subjects :

Action f'° 1 : Long term integrity of buildings and systems.

Action "3 2 : Decontamination for decommissioning purposes.

Action N° 3 : Dismantling techniques. .

Action N° 4 : Treatment of specific waste materials : steel, concrete and graphite. •

Action w0( 5 : Large transport containers for radioactive waste produced in the dismantling of nuclear power plants.

Action N° 6 : Estimation of tho quantities of radioactive wastes arising ' from decommissioning of nuclear power plants in the '

- Community. . '

’i

Action N° 7 : Influence of nuclear power plant design features on decommissioning.

B. Idcntification of guiding principles, namely : •

- certain guiding principles in the design and operation of nuclear power plant with a view to simplifying their subsequent decommissioning.

- guiding principles in tho decommissioning of nuclear power plant which could form the initial elements of a Community policy in this field.

58.

FINANCIAL SHEET


59.

1. Relevant budget heading code : 3359


2. Title of budget heading: .

60.

Decommissioning of nuclear installations


3. . Legal basis . ,

61.

Article 7 of the Treaty establishing the EAEC


62.

4. Description, objective and justification of the action


4.1. Description _ '

. This is a EURATOM research programme (indirect action) on the decommissioning of nuclear installations. The programme relates to the following topics:

- development of specialized techniques;

- forecasting of radioactive waste generation;

- study of certain power plant characteristics from a decommissioning .

63.

standpoint; *


- definition of guiding principles.

The programme primarily concerns electricity producers and public and private bodies competent in the field of nuclear research.

4.2. Objective * ,

/ 1

The objective of the action is to promote the development of methods and techniques for decommissioning nuclear installations in such a way as to ensure protection for man and his environment.

64.

4.3. Justification •


The proposed programme is the outcome of the action programme on the environment approved by the Council on 17 May 1977; it has been drawn up with the aid of a group of national experts. Action at Community l-evel will make for economy work through the exchange of information and the apportionment of tasks.

5. Financial incidence of the action (in EUA)

5.0. Incidence on expenditure

5.0.0. Total cost during the envisaged period ■

- from the budget of the Communities : 6,3.80,000 EUA

- from national admiriist rat ions :

- from other sectors at national level : _

5.0.1 Multiannual timetable ' Total cost : 6,380,000 EUA

Appropriations for commitment
197819791980198119821983
Staff

expenditure

Administrativ expenditure,

Contracts
e

24,000 .

476,000
262',000

49,000

2,000,000 ,
277,000

52,000

1,327,000
294,000

55,000

1,000,000
311,000

59,000
164,000

. 30,000
Total i 500,0002,311,000 ,1,656,0001,349,000370,000194,000
*

Appropriations for payment

1978. 19791980198119821983 ■
Staff

expenditure
— -262,000^ '

277,000
294,000311,000164,000
Administr. ' expenditure24,00049,00052,00055,500,59,000. 30,000
Contracts476,0001,000,0001,000,0001,000,0001,000,000327,000
Total500,0001,311,0001,329,0001,349,0001,370,000521,000

5.Ow2Method of calculation

a) Staff expenditure . .

The appropriations for this programme were evaluated on the basis of the following staff : , .

■ 2 officials of grade A

2 officials of grade B.

65.

. -I official of grade C


The calculations take account of the data as established for the setting-up of the draft budget for the year 1979. No net increase of salaries is assumed.> Only a variation of the weightings has been considered in order to take account of the trend in the general level of prices in the Community.

66.

b) Administrative and technical expenditure


They cover expenditures on missions and on the organization of , meetings as well as the utilization of scientific and technical support if appears necessary for the good development of the programme. ■

• c) Contract expenditure

67.

' Depending on the nature of the subject and the qualifications of


the contractors, no standard method of calculation can be laid down.

1 Anyhow, the Advisory Committee on Programme Management will be consulted on the awarding of appropriations.

d) Multiannual previsions *

The rates held for the calculations of the previsions are resp. : 1979 = 1.07; 1980 = 1.13; 1981 = 1.20;1982 = 1.27; 1983 = 1.34. .

'5.1 Implications on the funds ■ ’

6. Control regime foreseen .

Scientific control: ACPM and the responsible staff of the DO XII Administrative controls:

' Budgetary execution : Financial Control .

Regularity of expenditure : Division Contracts of DG XII.

68.

7. Action financing


69.

7.0 '


7.1

7.2

7.3 Appropriations to be entered under future budgets.

1

* The capacity of the reference plant is about 1200 MWe

2

- ' • , ■ . .

*’ Nickel-65: half-life of 90 years . , Nickel-59: half-life of £0,000 years

3

/ .

* This programme will require a staff of 5 (2A + 2B + 1C)