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Skid damper for
launching steam
generators for COMEX Nuclear

COMEX Nuclear

EPC contractor : ONET

AX System has designed and manufactured a shock-absorbing skid for steam generators, for COMEX Nucléaire and ONET. This project was carried out in compliance with the quality assurance rules in force at at COMEX-NUCLEAIRE, ONET and EDF.

An improved degree of tightness (IP 55 minimum but IP 65 preferable) allows in-depth cleaning
(HP cleaning) in the event of serious contamination of the equipment: motors, sensors,
cabinet, alarm light column, industrial quality cable gland.

Main components of the skid :
 A 500 bar Mini pressure gauge
 A 3-way pressure regulator with pneumatic proportional control, type PN2
 Two damping accumulators Type HYDRO LEDUC TYPE AF 0.45 P
 1 Khrone H250 M40 flow meter
 A manual drain valve
 The module will be piped in 316L stainless steel tube
 A watertight stainless steel box containing a connection terminal block and telemetry base.
flowmeter
 A stackable aluminium tube protection frame incorporating an arch.
 Gromelle 1/2 and Kamelock 1 1/2 inch fittings
 The module will be fitted with 4 castors, 2 of which have brakes.
 Maximum operating pressure set at 300 bar
 The safety valve will be certified and supplied with its setting certificate (400 bar).

PULSATION DAMPING SPHERE

The addition of an accumulator to a hydraulic circuit limits the rate of irregularity of the pumps. of the pumps, resulting in better operation of the system, protection and increased life The result is better operation of the system, protection and longer life for the circuit components, as well as a significant reduction in noise levels.
Volumetric ratio (V0-V2)/V0.
The volumetric ratio for this type of accumulator is 0.75.
An accumulator can absorb a maximum volume of : 75% and the inverse function is that the residual gas volume must not fall below 25% of the total volume.
Analysis of the pressure diagram gives us a practical value of 130 to 140 bars. can be used for the 450 bar test. This pressure must be able to be checked and adjusted with standard manufacturer’s tools.

Reference documents applicable to the project :

[1] D4507000059 Ind.5: Technical Note – General presentation of the evaporator of the steam
steam generators of PWR 900, 1300, 1450 and 1650MW units.
[2] D4507000060 Ind.4: Technical Note – General presentation of the water boxes
of the steam generators of the PWR 900, 1300, 1450 and 1650MW units.
[3] D4507081875 Ind.1 : CSCT – Design and Qualification of maintenance processes for the
the cleanliness of the secondary of Steam Generators.
[4] D4507081874 Ind.1 : CSCT – Secondary maintenance services for steam generators
all levels of PWR units.
[5] D5710/IMC/1999/00711 Ind 0 : Chemical Specifications for Products and Materials
Used in Power Plants (PMUC)
[6] D1353 PRG 058 – A: General purchasing conditions applicable to COMEX contracts
NUCLEAR
[7] C-MRQSE-AQ-011725-A.3 : COMEX NUCLEAIRE Quality Manual
[8] C-IMG 000-NT-084127 C-003357-NT-062520-A : ETV G IF Specifications

An improved degree of tightness (IP 55 minimum but IP 65 preferable) allows in-depth cleaning
(HP cleaning) in the event of serious contamination of the equipment: motors, sensors,
cabinet, alarm light column, industrial quality cable gland.

Main components of the skid :
 A 500 bar Mini pressure gauge
 A 3-way pressure regulator with pneumatic proportional control, type PN2
 Two damping accumulators Type HYDRO LEDUC TYPE AF 0.45 P
 1 Khrone H250 M40 flow meter
 A manual drain valve
 The module will be piped in 316L stainless steel tube
 A watertight stainless steel box containing a connection terminal block and telemetry base.
flowmeter
 A stackable aluminium tube protection frame incorporating an arch.
 Gromelle 1/2 and Kamelock 1 1/2 inch fittings
 The module will be fitted with 4 castors, 2 of which have brakes.
 Maximum operating pressure set at 300 bar
 The safety valve will be certified and supplied with its setting certificate (400 bar).

PULSATION DAMPING SPHERE

The addition of an accumulator to a hydraulic circuit limits the rate of irregularity of the pumps. of the pumps, resulting in better operation of the system, protection and increased life The result is better operation of the system, protection and longer life for the circuit components, as well as a significant reduction in noise levels.
Volumetric ratio (V0-V2)/V0.
The volumetric ratio for this type of accumulator is 0.75.
An accumulator can absorb a maximum volume of : 75% and the inverse function is that the residual gas volume must not fall below 25% of the total volume.
Analysis of the pressure diagram gives us a practical value of 130 to 140 bars. can be used for the 450 bar test. This pressure must be able to be checked and adjusted with standard manufacturer’s tools.

Reference documents applicable to the project :

[1] D4507000059 Ind.5: Technical Note – General presentation of the evaporator of the steam
steam generators of PWR 900, 1300, 1450 and 1650MW units.
[2] D4507000060 Ind.4: Technical Note – General presentation of the water boxes
of the steam generators of the PWR 900, 1300, 1450 and 1650MW units.
[3] D4507081875 Ind.1 : CSCT – Design and Qualification of maintenance processes for the
the cleanliness of the secondary of Steam Generators.
[4] D4507081874 Ind.1 : CSCT – Secondary maintenance services for steam generators
all levels of PWR units.
[5] D5710/IMC/1999/00711 Ind 0 : Chemical Specifications for Products and Materials
Used in Power Plants (PMUC)
[6] D1353 PRG 058 – A: General purchasing conditions applicable to COMEX contracts
NUCLEAR
[7] C-MRQSE-AQ-011725-A.3 : COMEX NUCLEAIRE Quality Manual
[8] C-IMG 000-NT-084127 C-003357-NT-062520-A : ETV G IF Specifications