Failure unrelated

There have not been significant process/prodnct failures attributable to causes other than operator error or equipment failures unrelated to equipment suitability... 

It is unclear whether previously published fire risk analyses have adequately ircaicd dependent failures and systems interaetions. Examples of either experienced or postulated system interactions that have been missed include unrelated systems that share common locations and the attendant spatially related physical interactions arising from fire. Incomplete enumeration of causes of failure and cavalier assumptions of independence can lead to underestimation of accident l rci uencies by many orders of magnitude,... 

In medical follow-up studies on the length of survival of patients after treatment, contact with some patients may be lost or some may die from causes unrelated to the disease treated. Similarly, in engineering studies, units may be lost or fail for some reason unrelated to the failure mode of interest for example, a unit on test may be removed from a test or destroyed accidentally. 

To determine maximum individual risk, generic frequency data are required for explosion events for Process Units 1 and 2. For Process Unit 1, incident data were available from the unit licenser identifying three explosions in approximately 15,000 operating years, for an explosion frequency of 2.0 x 10-4 per year. For Process Unit 2, a fault tree analysis of the nitrogen vessel brittle fracture event had been conducted as part of an unrelated project. That study concluded that the frequency of brittle fracture failure of the nitrogen vapor storage vessel was 5x10"4 per year. 

There are, however, several limitations and contraindications with MSC therapy. One of the limitations is in the establishment of MSC cultures from donors, parents or siblings. Although MSC can be readily isolated and expanded in vitro, establishing the MSC cultures can be a limiting factor. Failure to establish such cell cultures in a timely manner, and in sufficient qualities and quantities, may have profound consequences on the therapy. Since MHC compatibility is not necessary for MSC immunosuppression, and because MSC immunomodulatory activity can also be observed in third-party donor cells [656550], MSCs derived from unrelated, -unmatched, healthy, third-party donors would represent a universal donor MSC product with the advantage of being a readily-available product that may provide an opportunity for multiple and higher MSC doses, potentially at a reduced cost [659019 ]. 

It must be noted that API ignores failures that fall under the so-called double jeopardy principle (see API 521, March 1997, 4th edition, paragraph 2.2). Double jeopardy basically means two unrelated failures occurring exactly at the same time, that is, simultaneously. This does not mean the failures occurred one minute, one second or even one millisecond apart. It means at exacdy the same instant in time ... 

This is clearly a double jeopardy failure two unrelated events occurring at exactly the same time. One has nothing to do with the other. Therefore, you need to calculate the relief capacity for one scenario at a time. For the loss of power to a pump scenario, the relief load would be based on the amount of vapour generated at the normal rate of steam. For the steam control valve failure scenario, the relief capacity would be based on the amount of vapour generated by the heat provided by a wide-open steam valve even accounting for the amount of vapour condensed in this failure, the condenser would still be in operation. So the SRV should be sized for the worst condition. 

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