Some points on management of waste resulted from

decontamination

State agency on the Exclusion zone management

L. ZinkevychKiev

June 2013

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Works organization during decontamination

Before decontamination works there was carried out mapping and territory survey of:

centers of population – yard survey of possible places of nuclides accumulation (roofs, drains from the roofs)

agricultural lands forests roads and other facilities Vertical distribution of nuclides in soil was studied Based on the processed information there was made a decision

(often within 1-2 days) on territories decontamination

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Scale of works on decontamination after accident (outside the Exclusion zone)

№Kinds of

decontamination works

Measures

1986 1987 1988 1989 1990 Total

1 Moved contaminated soil

thous.м3 344 20 16 - - 380

2 replaced roofs unit 10360 519 3198 5048 13461 32586

3 replaced fenceskm 210 150 140 134 734 1368

4 Decontaminated:

public buildings unit 2257 3000 2043 - - 7300

childcare unit 455 - - - - 455

streets and roads thous.km more than 10

5 Asphalted roads and roadsides

km 400 - - - - 400

3*National report of Ukraine «15 years of Chernobyl catastrophe. Experience of overcoming». Kiev, 2001.

Table. Volume of works conducted in more than 430 centers of population in Kiev and Zhytomir oblast*

Decontamination experience (1)

For early (critical) fase:Radiologic criterion of decision making for decontamination - presence of contamination areas, where the dose rate on the 30th day after the accident exceeded 200-300 mR/h, which corresponded to the level of pollution 137Cs 5-10 Ci/km2; costs on a distracted man-Sievert in average reached values of 200-400 thousand dollars.haste in solving issues on decontamination waste storage, which led to a lot of points of disposal.

Since 1992, large-scale decontamination was carried out provided radioecologically sound and cost-effective projects:compliance with the basic principles of radiation protection: justification, optimization and not exceedance; works planned in such a way that the total (medical, economic, social and psychological) benefits to a man (society) was higher than the damage and was at most possible.

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Decontamination experience(2)

Radioecologically reasonable and cost-effective projects on the basis of dosimetry passportization materials were performed for 62 settlements (mainly related to the zone of guaranteed voluntary resettlement, where the total radiation dose of the population could exceed 1 mSv per year).

Analysis of the effectiveness of decontamination, which was held in several locations of Kiev and Zhitomir regions, shown that in result of works 15-30% of the total radiation dose is distracted, and the cost of abstract a man-Sievert ranges from 50 to 450 ths. dollars.

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PCDW, PSDW* and PST

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As of 31.12.2012 therea are 54 facilities: 47 PCDW, 1 PSDW*, 6 PST.

In the Exclusion zone there are – 8 facilities; Outside the Exclusion zone – 46 facilities

PCDW - point for collection of decontamination waste PSDW * - point for storage of decontamination waste PST - point for sanitary treatment of equipment and vehicles

Data on a number of facilities and waste

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Oblast Waste volume, м3

Total activity, kBq

Kiev 12019 9,17Е+07

Zhytomyr 9316 2,29Е+07

Chernihov 9300 No data

Total: 30635 11,46Е+07

Oblast Number of PCDW

Number of PSDW*

Number of PST

Kiev 11 - 6

Zhytomyr 25 1 -

Chernihov 3 - -

Total: 39 1 6

Waste type

Volume, м3

Solid 575,44

Liquid 295,00

Total: 870,44

Table. Data on waste at PCDW

Table. Data on waste at PST

Table. General number of facilities

Dedicated facilities outside the Exclusion zone

Works can be divided into two periods:

First - from 1986 till 1989 (without design documentation)

Second – from 1991 till 1995 (according to design documentation)

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General construction of PCDW: Bowl (trench or piled

dyke) Antifiltering screen

(bottom and the inside of the bowl)

Waterproofing screen

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First type of PCDW and PSDW

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Second type of PCDW and PSDW

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Waterproofing screen

Upper waterproofing screen includes (from top):Soil layer- 0,5 мDrain layer (coarse sand, gravel) — 0,3 мWaterproofing screen (clay) - 0,5 мGas-drain layer (coarse sand, gravel, road metal) — 0,5 м

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Decontamination waste classification

Waste decontamination is a radioactively contaminated material (building material, metal constructions, biomass, soil), which was formed during liquidation of the consequences of the Chernobyl disaster.

Decontamination waste according to radiation characteristics are classified this way:- Low-level radioactive waste;- Contaminated waste.

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Low-level radioactive waste

Solid decontamination waste with one of these radiation characteristics:

a) specific activity of waste exceeds 10 kBq / kg for sources of beta and gamma radiation;

b) absorbed dose exceeds 1,0 mkGy/h t a distance of 0.1 m from waste surface (for waste disposal);

c) exposure dose of decontamination waste exceeds 100 mR / h (for disposed waste).

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Contaminated waste Solid decontamination waste with one of these radiation

characteristics:

a) specific activity of waste exceeds:more than 1kBq/kg but less than 10 kBq / kg for sources of beta, gamma – radiation;

b) absorbed dose rate exceeds 1.0 mkGy / 1 h at a distance of 0.1 m from the waste surface (for waste disposal);c) exposure dose of decontamination waste exceeds the natural background, but does not exceed 100 mkR / h (for disposed waste).

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PSDW state control

Provides a central operation service of Kyiv SE

Regulation control - twice a year (spring and fall)

Technical state control lies in visual examination of engineering barriers

The measurement of exposure dose and flux density of beta-particles on the storage surface

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PSDW "Ripkinskyy"

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Description of technical stateof PSDW "Ripkinskyy"

As of 31 Dec 2007 it was given grade "unsatisfactory": theft (or destruction) of protective fencing around the perimeter of the PSDW security zone, signs of radiation danger “Radioactivity”

In 1997, 1999 construction works were executed at PSDW:

- protective fence around the perimeter of the PSDW security zone was built;

- Entrance gate was installed;

- Upper security screen at PSDW was built;

- Signs of radiation danger «Radioactivity» were installed. In future, if the signs of radiation danger "Radioactivity"

are stolen, personnel sets them on their own

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Capacity map of exposure dose on the surface of PCDW “Ripkinskyy”(as of fall, 2000), mkR/h

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Density map of flow of beta-particles on the surface of PCDW “Ripkinskyy”(as of fall 2000), particles/см2 per h

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PSDW "Ripkinskyy"

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Points of special treatment (PST), designed for decontamination of vehicles and equipment

1 type stationary is an engineering structure, which includes a sink (open or closed), reinforced concrete trestle, drainage network of settlers; besides sinks of existing transport enterprises;

2 type mobile is a military autoteeming station (АTS 12.14Y) on chassis of ZIL-131, which was located on an open area.

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THANK YOU FOR ATTENTION!

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