atw 2018-04v6

inforum

atw Vol. 63 (2018) | Issue 4 ı April

| | Fig. 7.

LB165 measurement of floor portions.

themselves. No cleaning procedures

were ever necessary and all the surface

portions could be considered not

contaminated and so able to be freely

released.

5 Radiological Characterization

of the Site

The third and last pillar of the decommissioning

of RB3 is the radiological

characterization of the areas of the

site surrounding the building. In this

regard, it is important to mention that

during the operational life of the

plant, given its low power and its

construction features, no radiocativity

discharges were in place and therefore

no environmental analyses were prescribed

by the Regulatory Authority.

Another point worth of mentioning is

that no radiological status of the site

prior to the construction and exercise

of RB3 is known. However, in light of

the graded approach which is going to

be taken for this third pillar by the

Regulatory Authority, given the fact

that no activated materials have been

found and that no activation or contamination

of the building has been

detected, it is decided to base this

characterization upon the measurement

of some selected nuclides in

certain terrain samples (soil) taken

around the area of the RB3 site.

In particular, 12 measurements of

239+240Pu through alpha spectrometry

will be done, together with

25 gamma spectroscopy assessments

for 54Mn, 60Co, 125Sb, 134Cs, 137Cs,

| | Fig. 9.

Collecting soil samples from the RB3 site.

Radionuclide

152Eu and 154Eu. Each terrain

sample will be a parallelepiped of

25x20x10 cm 3 corresponding roughly

to 5 liters of humid soil (Figure 9).

The site will be sampled considering

both near-range and far-range positions

in order to find patterns of radioactivity

correlated with the distance

from the RB3 building, if any at all.

The obtained values will be confronted,

through proper summations,

with the limits for the free release

of nuclear sites prescribed by the

German national law, which correspond

to the radiological nonrelevance

value of 10 microSv/year

to the public [8,9]. The limits for

the above-mentioned isotopes are

reported in Table 2.

References

[1] D.Lgs. 17 marzo 1995, n. 230,

Attuazione delle direttive Euratom

80/836, 84/467, 84/466, 89/618,

90/64, 92/3, 96/29.

[2] D. M. 29 Novembre 2010 Ministero

dello Sviluppo Economico di

Autorizzazione alla Disattivazione

Impianto Nucleare di Ricerca Reattore

RB-3 di Montecuccolino (BO) dell’ENEA.

[3] Radiation Protection 89, Recommended

radiological protection criteria for the

recycling of metals from the

dismantling of nuclear installations,

European Commission, 1998.

| | Fig. 8.

LB165 and its translational sledge to measure wall portions.

Concentration Limit

(Bq/g)

54 Mn 0.09

60 Co 0.03

125 Sb 0.08

134 Cs 0.05

137 Cs 0.06

152 Eu 0.07

154 Eu 0.06

239 Pu 0.04

240 Pu 0.04

| | Tab. 2.

Proposed clearance limits for the free release

of the RB3 site.

[4] Radiation Protection 113,

Recommended radiological protection

criteria for the clearance of buildings

and building rubble from the

dismantling of nuclear installations,

European Commission, 2000.

[5] I. Vilardi, C. M. Castellani, D. M.

Castelluccio, F. Rocchi, Piano di

Caratterizzazione Radiologica di Materiali

provenienti dalla Disattivazione

dell’impianto Nucleare di Ricerca Rb-3

dell’enea sito in Bologna – Montecuccolino

ai Fini del loro Allontanamento,

Convegno Nazionale AIRP 2014, Aosta.

[6] M. Capone, N. Cherubini, A. Compagno,

A. Dodaro, F. Rocchi, The Dismantling of

the Montecuccolino RB3 Research

Reactor: Radiological Characterisation of

Materials for Free Release, Proceedings

of the European Reaserch Reactor

Conference RRFM 2015, Bucharest

19-23 April 2015, 528-537.

[7] F. Meyer, F. Steger, R. Steininger,

Decommissioning of the Astra Research

Reactor – Dismantling the auxiliary

Systems and Clearance and Reuse of the

Buildings, Nuclear Technology &

Radiation Protection, 1/2008, 54-62.

[8] OECD/NEA Status Report, Releasing

the Sites of Nuclear Installations,

NEA Report 6187, 2006.

[9] Bundesgesetzblatt G 5702 Teil I, Bonn

26 July 2001, Nr. 38, 2001.

Authors

F. Rocchi

ENEA FSN/SICNUC/SIN

C. M. Castellani

ENEA IRP

A. Rizzo

ENEA FSN/SICNUC/TNM

Via Martiri di Monte Sole 4

Bologna (BO), Italy

A. Compagno

ENEA FSN/FISS/CRGR

I. Vilardi

ENEA IRP/SFA

Via Anguillarese, 301

00123 S.Maria di Galeria (RM), Italy

R. Lorenzelli

ENEA FSN/SICNUC/SIN

Località Brasimone

40032 Camugnano (BO), Italy

DECOMMISSIONING AND WASTE MANAGEMENT 245

Decommissioning and Waste Management

The Decommissioning of the ENEA RB3 Research Reactor in Montecuccolino ı F. Rocchi, C. M. Castellani, A. Compagno, I. Vilardi, R. Lorenzelli and A. Rizzo

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