Recently, we witnessed the disastrous earthquake and tsunami that has devastated the Japanese economy. The loss of life, property and infrastructure was on such a large scale, it was incomprehensible. Yet, Japan was more prepared for a large earthquake than any other country. The blow that was dealt to its power generation and distribution system has the potential to delay the country’s economic recovery more than any other loss of infrastructure. Prior to the disaster, Japan’s decision to reduce its oil dependency by implementing nuclear power generation was admired throughout the world. Now the name Fukushima may setback the worldwide nuclear power industry for decades as witnessed by Germany’s decision to shut down all of its nuclear power plants over the next 11 years. The cleanup of the Fukushima facility alone could end up costing Japan hundreds of billions of dollars and take decades. Through hindsight we are beginning to realize the chain reaction of events that could have been prevented through a few design changes in the plant. The disaster’s root cause was the tsunami since the plant was designed to survive the earthquake. Per recent news reports on what appears to be the plant’s root design flaws – had they been addressed prior to the tsunami – could have prevented most of the ensuing disaster.
Simply put, the plant did not have a reliable source of power. First, the backup power generators were rendered useless because they were installed at or below ground level and were flooded due to the tsunami. Next, the tsunami damaged the power transmission lines feeding the plant as it appears that they were above ground. Had the backup generators been installed above ground and located several miles inland, on higher ground, their operation would have been more assured. Additionally, if all of the backup power transmission lines had been installed in vault’s deep underground, there would have been a good chance the plant would not have lost critical power to the reactor, storage pond cooling and circulation pumps. Barring any other unknown conditions, the nuclear-related disasters that ensued might have been lessened or even averted. The total loss of power left the plant staff with a very limited number of options which they executed with selfless determination and valor.
Fukushima is not unique. The same set of conditions was true in New Orleans when it was hit by hurricane Katrina. The main hospital suffered a loss of both utility and backup generator power for several weeks. The hospital survived the main force of the hurricane, only to have the basement where the backup power generator was located flooded by the tidal surge that followed. Since that lesson, FEMA has issued new backup power guidelines for key installations like hospitals, police and fire departments. FEMA recommends power backup generators to be installed on the facility’s roof. They also recommend a third means of supplying power to these facilities. This would consist of an external building power interface connector that would facilitate connecting a drive-up or fly-in large generator to provide power to the facility as a last resort.
Preparing for the unforeseen
Facility productivity depends on a reliable, clean source of AC power. The fact is that natural or manmade disasters can happen anywhere and at any time. Fortunately, they are rarely of the magnitude of those in Japan or New Orleans. Unfortunately, power-related problems are very diverse in nature and cost industrial companies billions of dollars yearly through lost productivity, scrap and equipment damage. For example, one study reports that a large company that experiences a computer outage lasting for more than 10 days will never fully recover financially and that 50 percent of companies suffering such a predicament will be out of business within 5 years. A ten day outage represents a rare event as most power-related problems in the domestic industrial environment are very short in duration, but have a higher occurrence rate. Their cost to a company depends on the nature and severity of the power event, the critical nature of the process that would be affected, the susceptibility of key equipment to the power event and the nature of any resulting equipment damage. The good news is, barring a local disaster, the majority of power related problems can be mitigated by conducting a facility-wide power audit.
The audit should start at the building’s service entrance electrical panel and its related ground rod. This panel can be the doorway to some of the most serious and equipment damaging power problems. Voltages consisting of thousands of volts can be inadvertently fed from the utility side (high side) of the facility’s power transformer to its low voltage secondary side supplying power to the entrance panel, often referred to as “high siding.” High siding can result from power lines becoming crossed or a utility power transformer becoming shorted as a result of storm activity, traffic accidents, a defective transformer and natural disasters. Without high level Transient Voltage Surge Suppression (TVSS) protection installed inside the entrance service panel, a high side condition has the potential of damaging most of the equipment and lighting within the facility. TVSS will also help suppress high voltage transients caused from lightning strikes. In areas subject to lightning activity, an NFPA 780 compliant lightning rod system should be installed in combination with a low impedance earth ground rod system. The ground rod must be located near the entrance service panel since it reduces the risk of lightning damage and enhances the TVSS protection.