- Author
- Tanaka, T. J. | Nowlen, S. P. | Anderson, D. J.
- Title
- Circuit Bridging of Components by Smoke.
- Coporate
- Sandia National Labs., Albuquerque, NM
- Sponsor
- Nuclear Regulatory Commission, Washington, DC
- Report
- NUREG/CR-6476; SAND96-2633; NRC Job Code W6051, October 1996, 204 p.
- Keywords
- smoke | electronic equipment | damage | cables
- Identifiers
- digital equipment; circuit bridging tests on components; defining credible smoke exposure scenarios; review of smoke damage to electrical equipment; preliminary tests of the impact of smoke on digital I&C equipment; smoke exposure conditions for experimental digital trip system; impact of smoke on advanced I&C - selection of sample components and test matrix
- Abstract
- Smoke can adversely affect digital electronics; in the short term, it can lead to circuit bridging and in the long term to corrosion of metal parts. This report is a summary of the work to date and component-level tests by Sandia National Laboratories for the Nuclear Regulatory Commission to determine the impact of smoke on digital instrumentation and control equipment. The component tests focused on short-term effects such as circuit bridging in typical components and the factors that can influence how much the smoke will affect them. These factors include the component technology and packaging, physical board protection, and environmental conditions such as the amount of smoke, temperature of burn, ad humidity level. The likelihood of circuit bridging was tested by measuring leakage currents and converting those currents to resistance in ohms. Hermetically sealed ceramic packages were more resistant to smoke than plastic packages. Coating the boards with an acrylic spray provided some protection against circuit bridging. The smoke generation factors that affect the resistance the most are humidity, fuel level, and burn temperature. The use of CO2 as a fire suppressant, the presence of galvanic metal, and the presence of PVC did not significantly affect the outcome of these results.