Diesel generators starting

The accident resulted from a routine safety test of some electrical control equipment at the start of a normal reactor shutdown for routine maintenance. The test was to determine the ability to continue to draw electrical power from a turbine generator during the first minute of coast-down following a station blackout. In a blackout, the reactor automatically scrams and diesel generators start to assume load (about 1 minute required). 

The diesel generator start is only initiated by undervoltage actuation (25% of nominal voltage) on the 6.0 kV emergency busbar. Depending on the results of the reliability analyses, a second startup criteria "frequency low" could be proposed. 

The ac power cut would last for up to approximately two minutes, until such time as the onsite standby diesel generators started, warmed up and loaded or the plant operators transferred selected loads to the single reserve auxiliary transformer. This condition would result in a reactor trip, because of the loss of the four reactor coolant pumps, which are powered from the unit auxiliary transformer buses. 

Licensee Event Reports (LERs) Operator/Control Room Logs Diesel Generator Start Logs Maintenance Work Orders Post-Trip Analysis Reports NRC Gray Book Interview with Plant Personnel Other Plant Logs and Records... 

Bunker-fuel specifications for merchant vessels are described by ASTM D 2069, Standard Specification for Marine Fuels. Deep draft vessels carry residual (e.g., No. 6 fuel oil) or distillate-residual blend for main propulsion, plus distillate for start-up, shutdown, maneuvering, deck engines, and diesel generators. Main-propulsion fuel is identified principally by its viscosity in centistokes at 373 K. Obsolete designations include those based on Redwood No. 1 seconds at 100°F (311 K) (e.g., "MD 1500 ) and the designations "Bunker A for No. 5 fuel oil and "Bunker B and "Bunker C for No. 6 fuel oil in the lower-and upper-viscosity ranges, respectively. 

It is common practice to provide a standby emergency source of supply at all important installations such as large factories, railways, airports and other essential services. This is usually achieved with the use of a captive diesel generator (DG) set (Figure 16.1). Here we briefly discuss these machines, their characteristics and selection for a required application. We also consider schemes that are commonly used to start a DG set and run it individually or in parallel with an existing source of supply, which may be another DG set or an infinite bus. 

Captive (emergency) power generation covers the application of a diesel generating set, its starting, protection, synchronizing and load sharing. This forms an important part of power distribution at any installation to provide a standby source of supply,... 

EPRI NP-2433 addresses diesel generator reliability at nuclear power plants. The sources include plant records, utility records, and LERs. The report gives frequency of failure to start, failure. o continue running, and mean repair times. 

Four onsite power diesel generators that start automatically on loss of offsite power to reduce the frequency of the loss of station AC by an order of magnitude compared with ( , NDl 1 -6. This with the diesel driven auxiliary feedwater pump provides ample recovery imie... 

The Reliability of Emergency Diesel Gerterators at U.S. Nuclear Power Plants Nuclear Number of failures and demands lor 154 diesels Failure to start and failure to load and run data for Diesel Generators 106. 

Both scrubbers will be supplied with three sources of electrical power - the main grid supply, a back-up grid supply from a different substation and an emergency diesel generator. In the emergency chlorine scrubber, critical equipment items will be backed-up by automatic start-up of stand-by equipment. A gravity head tank of caustic soda and a nitrogen ejector will also be provided to allow safe neutralisation of chlorine vents in the event of total power failure. 

This year, in Folsom, California, Altergy Systems started up the world s first automated assembly line for manufacturing fuel cells. By contrast, a diesel generator costs 800 to 1,500 per kilowatt, and a natural gas turbine can be 400 per kilowatt or even less. This year, in Folsom, California, Altergy Systems started up the world s first automated assembly line for manufacturing fuel cells. 

According to these results, in the PV-hydrogen autonomous power system the PV panels should be overdimensioned in order to totally remove the diesel generator. In addition, the optimisation process showed that the battery bank can be removed, but in real systems a small battery bank is always necessary in order to take over the load for a small period of time (ca. 10 s) during start-up of the PEM fuel cell. In state-of-the-art PEM fuel cells a small battery bank is usually incorporated in the fuel-cell system. 

Since the 225 kV line was off-line at the time of the incident, tram A switchboards were without voltage The loss of voltage led to start-up of the tram A standby diesel generators (LHPE and LHPF)... 

The role of the power supply to guarantee the ESFAS actuation is fundamental. To respect the original design, each division has an Emergency Load Shedding System (ELS) to start a diesel generator. 

Start-up of a standby diesel generator was slow and a delay of between 25 and 50 seconds has... 

A Diesel generator is started 1,000 times. In 25 cases the start did not succeed. What is its probability of failure on demand ... 

Because the HTR-10 test reactor is designed on the inherent safety philosophy, safety classifications of systems and components departure from the way it is done for water cooled power reactors For example, primary pressure boundary is defined to the first isolation valve Steam generator tubes are classified as Class II component Diesel generators are not required to be as highly qualified as those used for large water cooled power reactors, since no systems or components with large power demand would require an immediate start of the diesel engines at a plant black-out accident... 

Diesel generator sets and fuel tanks, batteries, and charging system Plant lighting—alternate lights to have supplies from separate feeders A functional maintenance repair facility with adequate stocks of essential spares Storage tanks for all products, fuels, and starting materials—calibrated and tested for leaks... 

Emergency Power Diesel generator set, diesel storage tank, start-up battery, power change over switch ... 

The ESR exit line should be connected to the main water lines in the plant through solenoid valves which open automatically (with arrangement to open manually if it does not open) when power supply fails or when pressure in main line falls below a set pressure. This is to maintain supply of water to all important points of use till diesel generator set is started for resuming power supply to important pumps and other units. It will give the operators the vital 15-20 min to take necessary steps till these pumps are restarted (on power supply from the DG sets—which will be gradually loaded). 

The sequence of events which follows as a result of loss of off-site power as an initiating event were examined using event tree methodology. Initially, loss of power will result in the cessation of all equipment requiring power. This includes all lighting, ventilation components, control systems, monitors, instrumentation, etc. Normally, the loss of power will cause the standby diesel generator to automatically start and supply power to designated systems. If this occurs. 

Sequence B In the event of loss of off-site power, the backup diesel generator will automatically start and pickup designated facility loads. In general, important facility functions would remain available. In these circumstances, operations staff would be trained to secure operations in progress and consult with facility management as to any operations that should continue. 

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