Summary Report for Conduct of Kozloduy NPP Stress Tests

“Kozloduy NPP” PLC
SUMMARY REPORT
for Conduct of Kozloduy NPP
Stress Tests
supply system through a pair of channels. Water from Danube River is delivered to the cold channel
by pumps, located in bank pump stations.
Redundancy to connection to the Danube River is provided by Emergency pump station,
which ensure independent water supply in emergency reserve of the cold channel through two
independent pressure steel water lines.
Water for cooling of turbine condensers and for cooling of consumers in nuclear facilities is
delivered by circulation pumping stations with intake chambers and pumps, pressure steel pipelines
and filtering premises with filtering units. Facilities for removal of heated water are the removal
steel pipelines, siphon spillways shafts, low pressure removal channels, outlet shaft with the intake
chamber and overflow, inlet and inspection shafts. For the needs of Kozloduy NPP totally 4
circulation pumping stations (CPS) were constructed: one per two shutdown pairs of units 1-2 and
3-4 (VVER-440) and one per each of two nuclear power units 5 and 6 (VVER-1000).
CPS 3 and CPS 4 service the operating units, correspondingly unit 5 and unit 6. Two
pumping station are identical. Each pump station has the following:
· Motor-driven pumps for cooling of turbine condensers with water intake at elevation
of 29 m;
· Motor-driven pumps for service water supply to normal operation system consumers
in the turbine hall, reactor compartment, auxiliary building and chemically demineralised
water system with water intake at elevation of 28 m;
· Motor-driven pumps for water supply to the spray pools with water intake at
elevation of 28 m;
· Diesel-pumps for water supply to the spray pools with water intake at elevation of
26.3 m, virtually from the bottom of the cold channel;
· Fire-protection pumps with water intake at elevation of 26.3 m, virtually from the
bottom of the cold channel.
Series of the design measures have been implemented to prevent loss of connection to the
Danube River – measures to prevent loss of the pumping stations, tools to prevent blocking of the
main cooling water inlet, alternative ways of water supply, etc.
Redundancy for removal of spent service water from NPP site (units 5 and 6) to the Danube
River is provided with the second warm channel.
For water supply to the spray pools of units 5 and 6, independent water supply is provided
from the terrace of the Danube river, 6 shaft wells and 6 shaft pumping stations. Water amount
which can be delivered from the shaft pumping stations to the spray pools is sufficient to replenish
for losses from the six spray pools due to steaming and entrainment at quiet weather (wind speed of
2 m/s). Water from the shaft pumping station is delivered to the spray pools via separate steel
pipeline.
Cooling of the consumers of units 5 and 6 is provided from:
147/202