1.
Nuclear Power Plant Dukovany
1.1
Reactor Unit Scheme with identified main components
NPP Dukovany reactor unit scheme is shown in the Fig. 1-1. Following main components are
identified:
PRIMARY CIRCUIT
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
Reactor
Steam generator
Pressuriser
Spent-fuel storage pool
Refueling pit
Refueling machine
Main coolant pump
Pressure relief tower
HVAC system
Ventilation chimney
Main crane
SECONDARY CIRCUIT
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
High-pressure turbine stage
Low-pressure turbine stage
Generator
Condenser
Separator-reheater
Regenerative heaters
Feedwater tank with degasifier
Steam piping into turbine
Cooling circulation circuit piping
Insulated cables for generator power outlet
High-voltage transformer 400 kV
House transformer 6 kV
Manipulation crane
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Appendix 1 To the National Report of the Czech Republic
ref. no. 10366/2.0/2001
under the Nuclear Safety Convention
1.2
NPP technical parameters
Number of reactor units
Reactor Type
4
Pressurised water reactor
VVER 440/213
Steam generator body diameter
Steam generator body length
3.21 m
11.80m
Main coolant pump
Output parameters of one unit
Nominal thermal output
Generator output
Net electrical output
Own consumption
1375 MWt
440 MWe
388 MWe
52 MWe
Number per unit
6
Nominal power consumption
1.6 MW
3
Operational capacity
approx. 7000 m per hour
Rotor speed
1500 r.p.m.
Pump weight
approx. 48 t
Turbine
Reactor technical parameters
Reactor height
23.67 m
Pressure vessel inner diameter
3.542 m
Cylindrical part wall thickness
340 mm
Thickness of pressure vessel cladding
9 mm
Empty pressure vessel weight
215.15 t
Reactor weight
395 t
Reactor core
Number of fuel assemblies
312
Number of fuel elements per assembly
126
Number of control assemblies
37
Core height
2.5 m
Core diameter
2.88 m
Fuel enrichment
1.6/2.4/3.82* % U 235
Core loading (UO2)
42 t
Fuel cycle
four years with partly
transition to five years
* with profiled enrichment
Number of high-pressure sections
Number of low-pressure sections
Nominal rotor speed
Inlet steam temperature
Inlet steam pressure
1
2
3000 r.p.m.
o
256 C
4.3 MPa
Generator
Rated power
Output voltage
Nominal frequency
Cooling media
220 MW
15.75 kV
50 Hz
hydrogen - water
Condenser
Number per turbine
Number of pipes
per condenser
Water flow
Pipe material
Reactor cooling system
Cooling towers
Number of cooling loops
6
Inner diameter of main
cooling piping
500 mm
Volume of coolant
3
in primary circuit
209 m
Primary circuit working pressure
12.25 MPa
o
Inlet coolant temperature
approx. 267 C
o
Outlet coolant temperature
approx. 297 C
3
Reactor coolant flow
42 000 m per hour
Number per unit
Height
Diameter in top of the tower
Foot diameter
Wall thickness
Water flow (one tower)
Volume of evaporated steam
from one tower
1
approx. 31 716
3
35 000 m /hour
titanium
2
125 m
59.49 m
87.94 m
0.6-0.15 m
3
approx. 10.55 m /s
3
max. 0.15 m /s
Steam-generator
Number per unit
Steam production per SG
Steam output pressure
Steam output temperature
Steam generator weight
6
452 t. p h.
4,61 MPa
o
260.0 C
approx. 165 t
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Appendix 1 To the National Report of the Czech Republic
ref. no. 10366/2.0/2001
under the Nuclear Safety Convention
1.3
Modernization activities already carried out in Dukovany NPP
A) Activities carried out within the ”Back-fitting of NPP Dukovany”
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
A7
A8
A12
A21
A23
A30
A32
B1
B5
B7
B10
Main coolant pump control algorithms modification
Steam generator level measurement reliability improvement
Hydrogen recombination system within hermetic zone installation
High-pressure compressors replacement
Addition of redundant back-up to the category one power supplies No. 4
Teledosimetric system installation
Grab tank on Skryje stream installation
Cooling system installation for the machine halls roof steel structure
Stationary fire extinguishing equipment installation for central oil system
Unit electrical fire detection system upgrade
Stationary halon fire extinguishing system installation for unit electrical
equipment
B) Activities carried out within the ”Modernization of NPP Dukovany”
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
ZL 1702
ZL 2180
ZL 2374
ZL 3103
ZL 3582
ZL 3664
ZL 3701
ZL 3704
ZL 3818
ZL 3863
ZL 4290
P590
P591
P598
P602
P606
S150
S357
S439
S568
S675
S765
S776
S952
T130
T248
T263
T317
T370
Installation of electrical fire detection system at water pump station ”Jihlava”
Modernization of system for public warning during accidents
Construction of interim spent fuel storage facility
0.4 kV switchgears upgrade
TH 10 valves control
32/16/16 MVA back-up transformer installation
Pressure measurement in the OG box
Reconstruction of the protection actuated by “HPK break” signal.
EDU surroundings teledosimetric system. RA control data transfer
Fire-proof spraying of critical and important cable rooms
PV KO keys modification
AKOBOJE Automated Physical Protection System Optimization
Freon replacement in SZCH
Water treatment station modernization
MCR simulator
Roof flats construction for the EDU employees
Condenser reconstruction
Post-emergency hydrogen recombination
Replacement feeding water line for the SKŘ sensors flushing system
TQ sumps protection
Water and Oil coolers replacement in the diesel generator I station
Condensate treatment system modernization
Diesel generators electrical system reconstruction
Construction of intermediate floor in the PPR and SD rooms
Construction of new telephone switchboard
PV KO (relief valve) node reconstruction
HNČ replacement
Water and Oil cooler replacement for diesel generator II station
Replacement of TG pumps by a sealess type
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Appendix 1 To the National Report of the Czech Republic
ref. no. 10366/2.0/2001
under the Nuclear Safety Convention
30.
31.
32.
33.
34.
35.
36.
37.
T547
T556
T703
T764
T802
T982
T983
T984
First category power supplies system No. 4 batteries replacement
Control room diesel generator annunciation upgrade
SHNČ section collector displacement
SO continuous measurement system installation
Section switchboards service inlets of selected consumers reconstruction
Fire protection barriers
Fire protection barriers
Fire protection barriers
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4 of 9
Appendix 1 To the National Report of the Czech Republic
ref. no. 10366/2.0/2001
under the Nuclear Safety Convention
2.
Nuclear power plant Timelines
2.1
Reactor Unit Scheme with identified main components
NPP Temelín scheme is shown on Fig. 2-1. Following main components are identified:
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
Reactor
Primary circuit piping
Main coolant pump
Pressuriser
Steam generator
Polar Crane
Spent-fuel pool
Refueling machine
Hydro-accumulators
Containment
Ventilation stack
Emergency core cooling system
Diesel generator station
Machine hall
Feed-water tank
Main steam piping
High-pressure turbine stage
Low-pressure turbine stage
Generator
Exciter
Separator
Condenser
Heat exchanger
Coolant inlet and outlet
Pumping station
Cooling water pump
Cooling tower
Generator power output
Transformer
Power output
Distillate reservoirs
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Appendix 1 To the National Report of the Czech Republic
ref. no. 10366/2.0/2001
under the Nuclear Safety Convention
2.2
NPP technical parameters
Number of units
Reactor Type
2
PWR
VVER 1000
Steam generator body diameter
Steam generator body length
4,2 m
14,5 m
Main coolant pump
Unit parameters
Nominal thermal output
Generator output
Net electrical output
Own consumption
3000 MWt
981 MWe
912 MWe
69 MWe
Number per unit
4
Nominal power consumption
5.1 – 6.8 MW
3
Operational capacity
approx. 21 200 m p. hour
Rotor speed
1000 r.p.m.
Pump weight
approx. 156 t
Containment system
Reactor technical parameters
Reactor height
10.9 m
Pressure vessel inner diameter
4.5 m
Cylindrical part wall thickness
193 mm
Thickness of pressure vessel cladding 7 – 18 mm
Reactor weight without coolant
approx. 800 t
Pressure vessel weight
322 t
Reactor core
Number of fuel assemblies
163
Number of fuel elements per assembly 312
Number of control rods
61
Height of active core
3.6 m
Core height
3.1 m
Fuel enrichment
max. 5 % U 235
Core loading (UO2)
92 t
Fuel cycle
four years
Reactor cooling system
Number of cooling loops
Inner diameter of main
Cooling piping
Volume of coolant
in primary circuit
Primary circuit working pressure
Inlet coolant temperature
Outlet coolant temperature
Coolant flow
38 m
45 m
1.2 m
8 mm
Turbine
Number of high-pressure sections
1
Number of low-pressure sections
3
Rotor speed
3000 r.p.m.
High-pressure section weight
206 t
Low-pressure section weight
480 t
Generator
Rated apparent power
Power factor
Output voltage
Nominal frequency
Cooling media
Weight
1111 MW
0.9
24 kV
50 Hz
hydrogen – water
564 t
4
Condenser
850 mm
3
337 m
15.7 MPa
o
approx. 290 C
o
approx. 320 C
3
84 800 m /hour
Steam-generator
Number per unit
Steam quantity produced in
one steam generator
Outlet steam pressure
Outlet steam temperature
Steam generator weight
Height of cylindrical part
Inner diameter of cylindrical part
Wall thickness
Thickness of stainless steel liner
4
1470 t/hour
6.3 MPa
o
278.5 C
approx. 416 t
Number per turbine
Number of pipes
per condenser
Pipe length
Pipe material
3
approx. 32 000
12 m
titanium
Cooling tower
Number per unit
Height
Diameter in top of the tower
Foot diameter
Wall thickness
Number of askew columns
Water flow (one tower)
Volume of evaporated steam
from one tower
2
154.8 m
82.6 m
130.7 m
0.9 – 0.18 m
112
3
approx. 17.2 m /s
3
max. 0.4 m /s
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Appendix 1 To the National Report of the Czech Republic
ref. no. 10366/2.0/2001
under the Nuclear Safety Convention
2.3 Design changes performed at Temelín NPP
ITEM
No.
ITEM
REASON COMMENT
1
2
I&C Systems replacement
Nuclear fuel, control rods (lifetime)
1,3
1,3
3
4
5
6
7
Radiation monitoring system (RMS)
Primary circuit diagnostic system (TMDS)
Sipping
Bitumination system
Refueling machine I&C system replacement
3,2
4,1
2,3
1
3
8
9
10
11
Installation of compact grid in the spent fuel pool
Simulator
Technical support center
Inverters, rectifiers (AEG)
4
1,2
1
3
12
13
14
Penetrations (Škoda+ISTC Company)
Replacement of J2UX circuit breakers
Unit transformer penetrations (Passoni Villa bushings)
3
3
3
15
16
Addition of back-up power supply for reactor building No. 2
Addition of a common back-up diesel generator station (DGS)
17
Increase of accumulator batteries capacity
1
18
Implementation of "reserve electrical protections" and
provision for full selectivity in 6 kV radial electrical networks
Pressuriser electrical heaters continuous control
Installation of hydrogen recombination system
Post-accident hydrogen monitoring system
Replacement of selected valves
Reconstruction of stabile fire extinguishing system for outdoor
power transformers
Introduction of secondary load follow regulation
4
19
20
21
22
23
24
1
1,4
1
1
1
3
1
4
Unit 1 and 2 I&C. The replacement does not concern common and auxiliary I&C systems
New nuclear fuel brings significant nuclear safety improvement, radioactive wastes and
operational costs reduction
Original design of RMS did meet neither technical nor legislative requirements
Original design of primary circuit diagnostic system was not completely solved
Original (Russian) system did not meet new legislation and western standard requirements
Requirement for radioactive wastes reduction defined by PRE-OSART mission
Replacement of the original GANZ system with the system supplied by the ANSALDO
company
New compact grid enables significant increase of spent fuel pool capacity
provision for the operational personnel training
Fulfillment of the recommendations accepted after the TMI emergency
Replacement of the original (Russian) electrical instrumentation ABP (ANN) of safety
systems power supplies was initiated by the requirement for nuclear safety improvement
Provision for safe hermetic penetration
Initiated by negative operating experience at Bohunice and Dukovany NPPs (fires, etc.)
Replacement of original (Russian) penetrations because of negative operating experience
at other Czech power plants
Requirement for separation of power supplies for each unit
Addition of another back-up emergency power supply source for safety related systems
for the reason of provision of this power supply type for important and costly equipment
Replacement of original accumulator batteries because of negative operating experience
and with the intent to increase their operational capacity in case of total station blackout
Fully selective scheme providing for the elimination of failures in the electric part of the
individual units (short-circuits, problems with grounding, etc.).
The intent is to decrease ageing of primary circuit components
Elimination of hydrogen in the containment during accidents
Monitoring of hydrogen concentration during and after accident.
Replacement of unreliable valves
Inclusion of automatic activation; installation of additional barriers; installation of
additional nozzles
Technical requirements of ČEZ, a.s. defined in connection with the preparation of the
operation with UCPTE
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Appendix 1 To the National Report of the Czech Republic
ref. no. 10366/2.0/2001
under the Nuclear Safety Convention
ITEM
No.
ITEM
REASON COMMENT
25
Construction of plant terminal (TELETE)
4
26
Modification of the TVD and TVN water systems
4
27
28
29
30
Replacement of pumps
Modification of containment cesspool system
Containment venting (single failure)
Titanium condenser pipes installation
3
1
1
4
31
32
Control rod drives replacement
Introduction of new chemistry control
3
4
33
34
35
New safety analysis
ATWS analyses
PSA level 1 and 2 development project
1,2
1
1
36
37
38
39
40
41
Severe accidents analysis
SW independent verification & validation project (IV&V)
Leak Before Break
EOP development project
SAMG development project
Fire safety, cables, electronic fire detection system
1
2
1
4,1
1,4
2,4
42
Seismic analyses
1
43
Completion of documentation
2
44
45
46
47
ISE project
Modification of SG inner parts
Addition of new SG water level measurement
I&C system for polar crane replacement
48
49
Filtration system for emergency control room
Modification of main control room venting system
4,1
4
2
3
1
1
Technical requirements of ČEZ, a.s. defined in connection with the preparation of the
operation with UCPTE
Initiated by results of new hydraulic calculations to assure full system functionality in all
operating modes
Liquidation of manufacturers, unsuitable characteristics
Modifications based on results of tests performed in Russia
Sheathing of first closing valve and corresponding piping under the containment
Increase of pipes lifetime with the transition to a more effective chemistry regime (by
increasing pH)
Increase of the lifetime and reliability using innovated drives manufactured by ŠKODA
Increased quality of the chemical control enables to reach longer lifetime of important
components, in particular the steam-generator
Reworking of safety analyses in connection with the fuel and I&C replacement
Reworking of safety analysis in relation to latest findings in nuclear power engineering
level 1 – solves the probability of core damage
level 2 – solves the probability of releases due to core damage
Studies of selected severe (beyond design basis) accidents
Independent verification and validation of safety critical SW
Assessment of primary circuit integrity securing level (prevention against LOCA)
Symptom based emergency procedures development (prevention of accidents)
Guidelines for liquidation of accidents (logically linked with EOP)- accident mitigation
Replacement of original cabling with fire-poof and fire non-propagating ones; installation
of electronic fire detection system manufactured by CERBERUS.
Re-assessment of Temelín design against newly defined seismic loading - 0.1 g;
calculation of response spectra for each floor, rep. building; seismic re-qualification
Project for amendment and completion of required documentation related to safety related
equipment (strength, lifetime, seismicity).
Installation of computer based information system
Modification of the feeding node and SG separation (lifetime improvement)
Project assure separations of safety divisions
Replacement of the original ROBOTRON system with a new one, more reliable and
enabling addition of functionality
Addition of filters in HVAC system will enable use of MCR even during accidents
Assuring the main control room environment according to standards (temperature,
noisiness, etc.)
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Appendix 1 To the National Report of the Czech Republic
ref. no. 10366/2.0/2001
under the Nuclear Safety Convention
ITEM
No.
50
51
ITEM
58
Installation of GERB absorbers
Addition of drench fire extinguishing system for main coolant
pumps
Addition of radioactive waste treatment system for liquid
wastes liquidation after accidents
Addition of system for collection of boric water and system for
separation
Replacement of asbestos sealing
Installation of new heat-exchangers of active engineered safety
systems
Addition of relief valve to pressuriser system
Replacement of steam generator steam pipes quick-acting
valves
Modernization of main coolant pumps
59
60
Organized depository of high activity wastes
Replacement of freon in cooling systems
52
53
54
55
56
57
REASON COMMENT
2
2
Fulfillment of seismic requirements
Reaction to regulatory body requirements
1
Lowering of radioactive wastes volume
1
Lowering of radioactive wastes volume
4,2
3
1
3
4,1
2
2
Replacement with Teflon provides for increased technological equipment lifetime
Low quality of original heat-exchangers
Prevention of false actions of pressuriser safety valves
Protection of important and costly components
Provision for required coolant flow through the core, fixation of the impeller, rotor
balancing
Change of original radioactive waste depository concept
Reconstruction of cooling station with use of absorber units
Legend : Reason for design change:
1 – recommendation of individual missions and audits (IAEA, NUS Halliburton, TUV, etc.)
2 – requirement coming from regulatory body or/and from new legislation
3 – replacement of components because of low quality of original ones, loss of supplier, etc.
4 – ČEZ own decision
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9 of 9
Appendix 1 To the National Report of the Czech Republic
ref. no. 10366/2.0/2001
under the Nuclear Safety Convention