Kentucky Utilities-E.W. Brown Station - Executive Summary |
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E.W. Brown Generation Station, Kentucky Utilities, Mercer County, Kentucky, will be operating an inlet cooling system in June, 2000. This system uses approximately 32,000 pounds of anhydrous ammonia in two separate ice thermal storage tanks. Engineers and company officials have reviewed relevant data from other existing systems to assit them with engineering design and mitigation techniques. This process is required to comply with 40 CFR part 68, Clean Air Act Amendments, Risk Managment Plan. KU has developed a Risk Management and Process Safety Management Program to inform employees and management of the required procedures to maintain a safe operation. This system is a closed-loop system with automatic shutdown activation. KU has trained process operators and emergency response team members should an emergency occur. The worst-case scenario of losing all refrigerant in a low pressure vessel during winter isolation, a maximum of 9,418 pounds in a 10-minute period, would result in a release rate of 942 pounds per minute. The toxic endpoint, according to EPA table information, would involve a 1.8 mile area. However, a more realistic release scenario would involve liquid ammonia being released through the liquid line going to the evaporators. This scenario could occur if, while cleaning the strainer, valves where not properly isolated. Approximately 1,960 lbs of ammonia is in this line. Standard operating procedures require two employees to be performing the strainer cleaning task. Checklists are used to ensure proper valve isolation. Procedures that are in place to assist with quick mitigation of this type of release include: two operators performing this function so that if release occurs, isolation upstream can occur; radio communication to the control panel operator; trained emergency response personnel; and control panel operators reconizing a change in pressure. If this alternative scenario occurs, immediate notification from the operators at the release point to the control panel operators and a change in pressure noted at the control panel, would result in quick response to stop the release. It is believed that trained operators could stop the release within a 10-minute period. Immediate response would require isolation of the line upstream from the release which would reduce the amount of ammonia lost. Using EPA tables, this type of release would result in airborne concentrations possibly covering a 0.3 mile area. This process is also designed with an automatic shutdown system. Control panels will be monitored by trained personnel aiding in a quick response. Equipment used to process, store, and handle ammonia are designed, constructed, installed, and maintained to minimize the risk of releases. KU's computerized maintenance management system enables personnel to provide continuous maintenance. The maintenance system is computerized and encompasses all phases of maintenance management including problem reporting, res ource scheduling, generation of preventative maintenance work orders, equipment database and complete equipment history. Safe operation of the system is a common goal for all E. W. Brown employees. This effort is supported through programs described previously and the involvement of plant management in development and implementation of the Process Safety and Risk Management Programs. |