Equipment for Generating Radiated Electrical Signals

Equipment for Generating Radiated Electrical Signals

Suppliers are being sought for equipment and approaches to deal with electronic noise, as described herein.

Symptom: Electronic noise in a production environment, such as radiated electrical signals from nearby welding, grinding or equipment start-up, can effect coaxial cables supplying sensitive measurement equipment, causing erroneous signals. Although the spurious signals are on the order of 10-11 amps and might be considered insignificantly small for many applications, their appearance in sensitive nuclear plant instruments is problematic. This happens most commonly during production, maintenance or plant start/stop operations.

Cause & Context: Radiated electric and magnetic fields from production operations or from equipment transients (starts and stops) are to be expected. These fields can induce currents in cables connected to nearby sensitive measurement instruments. However, the operation causing offending electronic noise in a particular instrument is not always evident. In addition, the reason spurious signals are seen in one instrument but not others of similar design, construction and location is not always evident. Troubleshooting is time consuming and expensive and can impact critical path schedules.

Repair and mitigation steps are also time consuming and expensive, as the affected cables are often in hard-to-access locations. Technology to help eliminate the susceptibility of co-axial cables to radiated electrical noise, and/or to speed up the troubleshooting process, is being sought.

Desired End State: A near-term end state in which new tools are available to replicate the current-inducing characteristics of the operations cited above is the primary objective. This will allow testing to determine the vulnerability of a particular cable/instrument, without impacting critical path schedules.

A near-term end state in which faster alternatives to current mitigation methods are available is a second objective. Current methods usually involve shielding with metal sheets or foils, replacing cables or re-cleaning cable connections.

A long-term end state in which cables can be made immune to radiated signals is desirable. A long-term end state in which the vulnerability of cables to radiated signals can be quickly assessed using readily available or easy-to-obtain information is also desirable.

Candidates: The solution of most immediate interest would be a portable device capable of generating electrical noise to help identify susceptible coaxial cables early in the production or maintenance process. Such a device would have the following characteristics:

- Can fit through a 30” diameter opening

- Have an antenna (loop) capable of reaching in areas with minimal clearance, able to extend up to 20 feet

- Variable signal strength and frequency from 15 Hz to 60 kHz

- Target co-axial cable signal strength is typically between 10-10 to 10-11 amps or discrete counts (pulses).

- The target co-axial cable is Mil Standard M17/233-00001 or M17/126-RG391 (98) contained within conduit with a minimal number of connectors.