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Zinkevych L I

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Some points on management
of waste resulted from
decontamination
State agency on the Exclusion zone management
L. Zinkevych
Kiev
June 2013
1
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)
пѓ� agricultural lands
пѓ� forests
пѓ� 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
пЃ®
2
Scale of works on decontamination after accident
(outside the Exclusion zone)
Table. Volume of works conducted in more than 430 centers of population in Kiev
and Zhytomir oblast*
Kinds of
decontamination
works
Measure
s
1986
1987
1988
1989
1990
Total
1
Moved contaminated
soil
thous.Рј3
344
20
16
-
-
380
2
replaced roofs
unit
10360
519
3198
5048
13461
32586
3
replaced fences
km
210
150
140
134
734
1368
4
Decontaminated:
public buildings
unit
2257
3000
2043
-
-
7300
childcare
unit
455
-
-
-
-
455
-
400
в„–
streets and roads
5
Asphalted roads and
roadsides
thous.km
km
more than 10
400
-
-
-
*National report of Ukraine В«15 years of Chernobyl catastrophe. Experience of overcomingВ». Kiev, 2001.
3
Decontamination experience (1)
For early (critical) fase:
пЃ® 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.
пЃ® 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:
пЃ® compliance with the basic principles of radiation protection: justification,
optimization and not exceedance;
пЃ® 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.
4
Decontamination experience(2)
пЃ®
пЃ®
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.
5
PCDW, PSDW* and PST
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
6
Data on a number of facilities and waste
Oblast
Number of
PCDW
Number of
PSDW*
Number of PST
Kiev
11
-
6
Zhytomyr
25
1
-
Chernihov
3
-
-
Total:
39
1
6
Oblast
Waste volume,
Рј3
Total activity,
kBq
Kiev
12019
9,17Р•+07
Zhytomyr
9316
2,29Р•+07
Chernihov
9300
No data
Total:
30635
11,46Р•+07
Waste
type
Volume, Рј3
Solid
575,44
Liquid
295,00
Total:
870,44
Table. General
number of
facilities
Table. Data on waste
at PCDW
Table. Data on
waste at PST
7
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)
пЃ®
8
General construction of
PCDW:
пЃ®
пЃ®
пЃ®
Bowl (trench or piled
dyke)
Antifiltering screen
(bottom and the
inside of the bowl)
Waterproofing screen
9
First type of PCDW and PSDW
10
Second type of PCDW and PSDW
11
Waterproofing screen
Upper waterproofing screen includes
(from top):
пЃ® Soil layer- 0,5 Рј
 Drain layer (coarse sand, gravel) —
0,3 Рј
пЃ® Waterproofing screen (clay) - 0,5 Рј
пЃ® Gas-drain layer (coarse sand, gravel,
road metal) — 0,5 м
12
Decontamination waste classification
пЃ®
пЃ®
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.
13
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).
пЃ®
14
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).
пЃ®
15
PSDW state control
Provides a central operation service of
Kyiv SE
пЃ® Regulation control - twice a year (spring
and fall)
пЃ® Technical state control lies in visual
examination of engineering barriers
пЃ® The measurement of exposure dose and
flux density of beta-particles on the
storage surface
пЃ®
16
PSDW "Ripkinskyy"
17
Description of technical stateof
PSDW "Ripkinskyy"
пЃ®
пЃ®
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 В«RadioactivityВ» were installed.
пЃ®
In future, if the signs of radiation danger "Radioactivity"
are stolen, personnel sets them on their own
18
Capacity map of
exposure dose on
the surface of PCDW
“Ripkinskyy”
(as of fall, 2000),
mkR/h
19
Density map of
flow of betaparticles on the
surface of PCDW
“Ripkinskyy”(as of
fall 2000),
particles/СЃРј2 per h
20
21
22
23
PSDW "Ripkinskyy"
24
Points of special treatment (PST), designed for
decontamination of vehicles and equipment
пЃ®
пЃ®
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
(РђTS 12.14Y) on chassis of ZIL-131, which was
located on an open area.
25
THANK YOU FOR
ATTENTION!
26
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