Pump operating experience

Long-term operation of the reactors BOR-60, BN-350 and BN-600 has provided a soxmd basis for the design and technical decisions adopted for the sodium piunps. The pumps are working reliably and ensure all the specified modes of reactor operation. The BOR-60 pumps have been operated since 1969, and the maximum service age of the primary pumps exceeds 25 years without replacement of the internals. Similarly the BN-350 pumps have 24 years of operating experience. The BN-600 pumps, which are some of the biggest in the world, have the following performance indicators  

operating Sodium Pumps Main Data 

Saeend. priB. olro. olro. oiro- 

Pnraaetar olro. CRM-ll oirOa CM-IO eire. cm-2,3 eire. Cmi-7,3 eire. Cim-14 eire. cn-14 elm. cmi-7,2 olre. eire. CHR-IO CMS-10 eire. olro. 

Reliable sealing of the internal cavities of the pumps from the environment is provided by hydrodynamic shaft face seals with an oil-sealed joint (Fig. 8.8). The seal allows a pressure difference of up to 2 MPa and ensures a minimum steady oil leakage flow of less than lOcm /h independent of the mode of operation. There were no difficulties with the repair seals (Fig.8.9) which performed the function of the main shaft seals during their replacement when the pump is shut down. 

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The causes of low pressure, for example, could be cither hydraulic or mechanical. In many cases of failure analysis, asking Wliy. and Wliat and answering those questions, until you can no longer ask why , will almost always get you to the answer. If all evidence leads to a mechanical reason for the failure, the problem is probably maintenance induced. If the evidence leads to a hydraulic reason for the failure, the problem is eitJier operations or design induced. In cases where the reason for failure was not determined, a more extensive analysis is necessary. The additional analysis is recommended to take advantage of the pump supplier experience in identifying the root cause. 

The component failure rate data used as input to the fault tree model came from four basic sources plant records from Peach Bottom (a plant of similar design to Limerick), actual nuclear plant operating experience data as reported in LERs (to produce demand failure rates evaluated for pumps, diesels, and valves), General Electric BWR operating experience data on a wide variety of components (e.g., safety relief SRV valves, level sensors containment pressure sensors), and WASH-1400 assessed median values. 

Abstract. Newly established residential area in Vastra Hamnen (West Harbour) in the city of Malmo uses Aquifer Thermal Energy Storage (ATES) as part of the district heating and cooling system. ATES system has 5 warm and 5 cold wells that are 70-80 m deep. Cold from the nearby sea (Oresund) and water cold from heat pump is stored from winter to summer. The purpose of the system is to deliver free cooling to district cooling system at a temperature level below +6-8 °C. Operational experiences and economic aspects are discussed. 

The results for the A state show that a different mechanism is operative. A series of femtosecond pump-probe experiments were performed at wavelengths corresponding to the Rydberg states A (v = 0,1,2) of ammonia molecules.64-66,68,69 The wavelengths used to access these vibrational levels were 214 nm, 211 nm, and 208 nm for the pump laser and 321 nm, 316.5 nm, and 312 nm for the probe laser, respectively. 

In Hydrocyclones A Solution to Produced Water Treatment, Meldrum presents the basic design principle of a dc-oilmg hydrocy leone. System design, early operational experiences, and test results on a full-scale application in the North Sea are discussed. Oil-removal efficiency was seen to rise with increasing reject ratio up to around 1%, producing acceptable outlet concentrations Early field test results on a tension leg platform in the North Sea are discussed. Preliminary data on a pumped system are also given. 

Extensive experimental work was undertaken at Babcock and Wilcox to obtain detailed heat transfer and pressure drop information as well as operating experience. Summary articles by Rhode et al. [245] and Schluderberg et al. [246] elaborate on the conclusions of this work. Heat transfer coefficients for heating were improved by as much as a factor of 10 through the addition of graphite. The suspensions were also shown to be far superior to gas coolants on the basis of pumping power requirements, especially when twisted-tape inserts... 

Empty module operation vacuum need to be pumped before experiment, which means waste gas of the last experiment need to be pumped, vacuum module and experimental section need to be separated with diaphragm (Xu et al. 2012). 

Based on French operating experience and usual operating procedures, it has been suggested that the main sodium pumps of EFR Consistent Design be equipped with pony motors in order to assure sodium forced convection in secondary circuits in any configuration. 

The high limit is based on operating experience it has been found that upsets rarely cause the level to deviate more than 2% or 3%. Therefore, keeping the level at 95% or less should minimize the chance of tank overflow. Minimum flow protection for the pumps, P-101 A/B, is not provided so a minimum level in the tank must be maintained to jnevent pump cavitation leading to seal leaks. ... 

The first edition of an operating manual often contains excessive technical information because it is written while the facility is still in the design or constmction phase. These procedures are typically written by design engineers who know the process and equipment but who do not necessarily have much operating experience. Hence they may describe the material of construction and the design parameters of a pump in some detail, but provide little or no information on how to actually operate that pump. 

The BN-350 is a fast breeder reactor located in Aktau, Kazakstan on the eastern shore of the Caspian Sea. The reactor began operation in 1972. It operated on an open uranium fuel cycle optimized to produce plutonium for the USSR weapons complex and generated steam for electricity, heat and seawater desalination. The reactor was in operation until April 1999 when decision for final shutdown had been taken by Government. In this report the operational experience is considered for the following equipment that directly contacts the liquid metal coolant The main circulation pumps of primary circuit ... 

After analyzing the preceding two classes of failures those dependent failures which are due to a common (shared) cause (CCF) remain to be explained. The common cause may be a design or construction flaw or a maintenance error, e.g. unsuitable lubricants used for pump bearings. CCFs are introduced into the fault tree in addition to the independent failures of the components involved. Probabilities are assigned to them using model-based evaluations of operating experience. 

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