Pump seal failure

In evaluating event frequency, past incidents can provide invaluable guidance. For example, if a pump seal failure is identified as having the potential to lead to a vapor cloud release, and if previous pump seal failures have occurred frequently, it might be reasonable to conclude that such a scenario is likely. This conclusion may be valid even though previous pump seal failures did not result in a vapor cloud. 

Liquids under pressure (pipeline leaks, pump seal failures, etc.), will be thrown some distance from the point source, while atmospheric leakages will emit at the point of release. The other characteristic of liquid releases is their flash points. High flash point liquids, not operating above their flash point temperatures, are inherently safer than low flash point liquids. Most liquid fires are relatively easy to contain and suppress while gas fires are prone to explosion possibilities if extinguished and source points are not isolated. 

Pump seal failure released liquids which ignited. 

Of the fires, about 50 percent occurred during construction, 25 percent were due to pump seal failure, and the remaining 25 percent resulted from engineering and operational oversights that a HAZOP study possibly could have prevented. 

More Temperature — Pump seal failure, vapor lock Install a feedback line... 

More Flow Line fracture Pump seal failure Control fault Spillage (possible large explosion) Spillage (possible small explosion) Consider bypass... 

In case of pump seal failure, pump seals should be replaced, or the piston should be checked for scratches and should be replaced if necessary. 

Line supervisors and superintendents are often called upon to conduct a quick root cause analysis immediately following an event. Using the example of the pump seal failure, the line managers will be faced with questions such as ... 

The primary causes for loss of containment of fluids are pipe or flange failure, pump seal failure, explosions, fires, overfilled tanks, over-pressured tanks, and overturned drums or containers. Because loss of containment creates serious situations, the early... 

Small LOG A in older design was caused by pump seal failure. This has been eliminated by selection of canned rotor pumps. These pumps have a considerable operational experience. If the circulating pumps position is selected in the RPV bottom area to avoid cavitation, their penetration has to be designed to the same standard as the RPV head with regard to integrity and inspectability. 

ISSUE TITLE Reactor coolant pump seal failures (PC 3)... 

Reactor coolant pump seal failures could significantly challenge the makeup capabilities at nuclear stations In PWRs. this can notably happen during station blackout conditions... 

NUREG/CR-5167, Cost/benefit analysis for Generic Issue 23, Reactor coolant pump seal failure. NUREG-0933, Generic Safety Issue 23. 

The operators asserted during interviews that they were concerned about a inducing a LOCA by a reactor coolant pump seal failure, and decided to go on natural circulation. To establish natural circulation would have required (among other things) subcooled reactor coolant. The operators assumed that, because the pressurizer level was high, the core must be covered. In actuality, natural circulation was precluded by the steam that had formed in the reactor coolant system. It was the higher... 

Several biocompatible HPLC and UHPLC systems are also available, engineered with a bio-inert flow path made of non-stainless steel materials (such as titanium or PEEK) for protein analysis. Stainless steel equipment and tubing should be avoided for protein analysis by aqueous/salt-based methods because protein chelation with metals can negatively affect separation (19). These interactions can either occur with metal contaminating the column or with corroded surfaces within the instrument. In addition to affecting separation, corrosion can result in physical damage to the system, such as pump seal failure and compromised performance of the detector cells. Stainless steel systems may require periodic passivation for reliable usage (20). 

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