Mineral Insulated Instrumentation and Control Cable for Reactor Core is under the special requirement of high-performance instrumentation systems which should be the provision of adequate interference immunity. The overall chain from the signal source to the measurement should be overall applied. Because of the following mentioned advantages, Mineral Insulated (MI) cables are now widely used in the reactor core.
Avoiding standard MI cables which are inadequate in maintaining immunity and low losses, the special cables supplied by Pasia are designed to, through regions of high radiation and temperature, electromagnetic noise found from the nuclear reactor core, transmit very small pulse or dc signals.
Specialized cable structure can maintain a certain high level of insulation resistance and make the surface transfer impedance minimized. Based on this philosophy, multiple metal and insulating sheaths should be adopted. The MI cables will operate in high neutron flux fields and at temperatures of up to 900 ºC whilst maintaining a high insulation resistance.
At their typical operating temperature of 550 ºC, the insulation is better than 3x10-9 amps per metre.
Parameters | Technical data | |||
Coaxial | Double shield | Triax | ||
Conductor | Cores | 1 | ||
OD,mm | 0.20 - 3.18 | |||
Insulation thickness | Inner,mm | 0.35 - 6.1 | ||
Outer,mm | - | 0.40 - 1.0 | ||
Cable OD,mm | 4.0 - 19.1 | 3.0 - 19.1 | ||
Sheath thickness,mm | 0.25 - 1.60 | 0.30 - 1.90 | ||
Characteristic impedance,Ω | 50±5 | |||
Insulation thickness
|
Core – inner shielding | ≥ 10000 MΩ | ||
Inner shielding – outer shielding | - | ≥ 10000 MΩ | ||
γ radiation dose,Gy/h | ≥ 2 × 106 | |||
Maximum withstand temperature | ≥ 900℃ / 2min | |||
Structure materials (optional) |
Conductor | Copper, nickel chromium or pure nickel | ||
Inner insulation | High-pure MgO,Al2O3,SiO2 | |||
Inner shielding | - | Copper,,304L,321,316L | ||
Outer insulation | - | High-pure MgO,Al2O3,SiO2 | ||
Outer shielding | - | - | Copper, | |
Sheath | 304L,321,316L,Inconel 600,Alloy 825 |
Features
■ Optimised geometries to minimise surface transfer impedance
■ Designed to maintain screening performance of measurement chain
■ Very high insulation resistance to minimise signal losses
■ All cable supplied fully tested
■ Maximum operating temperature of 700 ºC in high neutron flux fields
■ Dimensions and lengths can be adapted to particular applications