Prezentare Situatie iazuri CoSIDIM la data de 30.04 · •Mining works connected with the surface...

REPEDEA POIENILE MINE CLOSURE AND GREENING 1

PRESENTATION

S. “CONVERSMIN” S.A. Bucharest

REPEDEA POIENILE MINE CLOSURE AND GREENING

S.CONVERSMIN S.A.


Repedea Poienile de sub Munte exploration sector

is located in the northern country, 23 km north

towards the town of Vişeul de Sus, within the

municipalities Repedea and Poienile de sub Munte.

S. CONVERSMIN S.A. REPEDEA POIENILE MINE CLOSURE AND GREENING 2


The mining sector is divided into two areas:

A. Repedea

B. Zănoaga – Poienile de sub Munte.

• Mining works connected with the surface are 5

galleries that are executed as a result of geological

research.

• 3 galleries are located in the mining sector Repedea

and 2 in the mining sector Poienile de sub Munte.

• Closing these coastal galleries was achieved through

embank and sealing with concrete walls.

S.C CONVERSMIN S.A. REPEDEA POIENILE MINE CLOSURE

AND GREENING4


Also in Repedea-Poienile perimeters are 5 dumps,

located at the mouth (entrance) of galleries.

3 dumps are located in the mining sector Repedea:

- dump G1 Repedea

- dump G2 Repedea

- dump G3 Repedea

and 2 dumps in the mining sector Poienile de sub

Munte:

- dump G1 Zănoaga

- dump G2 Zănoaga


AND GREENING5


Greeneing dump Gallery G1 Repedea

Before remediation work gamma dose rate was

situeted between 0,30µSv/h and 9µSv/h on foreland

and slope.


AND GREENING6



Flow rate range dose before greening


According to technical project greening dump G1 works

consisted in:

relocation of the radioactive material in the gallery;

geometrization of the dump slope;

channel for rainwater evacuation from the platform of

the gallery;

fitting the carpet of geocells on the dump slope and

filling with inert material from the dump;

At the end of the works a measurements of gamma dose rate

was made. The results obtained showed values less then 0,30

µSv/h.



After greening a gamma dose rate distribution on the surface of the

dump from G 1. Repedea



Flow rate range dose before and after work remediation



Greening Dump gallery G2, elevation + 903 m.

Determinations made in 2007 regarding the gamm's dump dose flow

pinpoint on small areas (~ 20m2 ) values up to 0,36 µSv/h.



For stabilization, landscaping and greening of the dump

gallery G2, the work focused on the following aspects:


reinforced rubble rock channel for the discharge of

stormwater from the platform of the gallery;

relocation of slightly contaminated material in the gallery;

alveoli fill of the geocellular carpet with inert material

from the dump;

the closure of the gallery with a concrete walls



Upon completion of the work of greening a

investigation was carried on the characteristics of the

radioactive dump.

1.Flow gamma dose performed with the grid system,

highlighted values between 0,15-0,26µSv/h.

2.The concentration of Radon on the dump and on the

mouth (entrance) of the Gallery is between 20-25 Bq/

m3.



Gamma dose rate distribution on the surface of the dump from G.2.

Repedea after greening



Gamma dose rate before and after work remediation



Greening dump gallery G3, elevation + 795 m.

According to the closures technical project were carried

out the following work to fix it:

relocation work of the dump material in order to

complete the volume of backfill in the existing gallery;


reinforced rubble rock channel for the discharge of

stormwater from the platform of the gallery;

channel with steps on the slope for mine water;

closing the mouth of the gallery.



Determinations made in 2007 have highlighted gamma

dose rate values of up to 0,30 µSv/h.

After the end of the reconstruction works, gamma dose

measurements in flow rack 2x2 m showed a distribution

on the whole surface between 0,16-0,27µSv/h.

Radon concentrations were 18 Bq/ m3 on the dump and

25 Bq/ m3 at the entrance in Gallery.



Gamma dose rate distribution on the surface of the heap from G.3.

Repedea after greening



Gamma dose rate before and after



Within the perimeter Poienile de sub Munte


For stabilization, landscaping and greening of the dump gallery

G1 were executed the following works:

• relocation works of radioactive material into the existing

gallery;

• geometrization of the dump;

• installing geocelular carpet;

• alveoli fill of the geocellular carpet;

• planting seedlings over the dump platforms.



Dose rate gamma values resulting from the investigations

carried out in 2007 were between 0,2-3,5 mSv/h, and surface

flow intensity gamma dose greater than 0,30 mSv/h occupies an

area of 190 m2 .

On the surface of the dump after decommissioning works-

greening, it was determined the distribution of dose rate with

the rate values range between 0- 0,29µSv/h.

Radon concentration is 21Bq/mc on the dump and 24 Bq/mc at

the mouth of the gallery.




Poienile after greening



Gamma dose rate before and after work remediation




Gamma dose rate determinations made in the network of 2007, also

highlighted values between 0,17-0,30 µSv/h.

The work focussed on the following issues:

relocation works of the inert material for backfilling the existing

gallery;


reinforced rubble rock channel for the discharge of stormwater

from the platform of the gallery;

closing the mouth of the gallery.

Upon completion the work determination has been made to fiind out

the dose gamma rate their for emphasising the values between 0,15-

0,29 µSv/h, and concentrations of radon is 23Bq/mc.




Poienile after greening



Gamma dose rate before and after greening



CONCLUSIONS

Upon completion the remediation works at the

former mining sector Repedea-Poienele de sub Munte

there were no longer found radioactive materials and

contaminated land.


28

Specialized operator in ecological rehabilitation of mining

affected sites and post closure monitoring

Thank you for

support and good cooperation!

“CONVERSMIN” S.A. – Bucureşti

S.C CONVERSMIN S.A. REPEDEA POIENILE MINE CLOSURE AND GREENING

Prezentare Situatie iazuri CoSIDIM la data de 30.04 · •Mining works connected with the surface...

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