Redundant Verification

Each test included in a given type of tests must be submitted to a validation procedure applied to the implementation of the methods in the laboratory, and must be regularly evaluated with triply redundant verification procedures ... 

At the same time, internal quality control must be carried out to verify the performance stability of the limited-scope performance of the method. Triply redundant verification methods are carried out with regard to control of first, second and/or third line, each set of methods applied to a particular type of test. The first line of verification involves pro forma repetition of all the steps of the test, in order to establish repeatability or reproducibility for quantitative tests, and to verify the range of sensitivity or detection for qualitative tests. This verification is performed by the experimenter himself, as part of the proper performance of the test. A second line of verification is put into operation by administrative decision, and includes testing with blind samples, repetition of samples, internal audit procedures, etc. If necessary, a third line of verification can be set up by the use of certified reference materials (or spiking materials), or through collaborative trials. These procedures are based on external cooperation. External audit procedures and complaints handling procedures are also part of this third line of verification. 

Rather than do a formal PSSR, would it be wise to ensure final check steps for redundant verification of critical startup activities are built into the last section of the startup after emergency shutdown operating procedure ... 

Level 2 is usually based on dual acquisition of inputs, functional redundancy, verification of temporal constraints and data controls. For level 3, the question/answer game is available in ROM and the main unit provides incorrect answers in order to verify that the control unit can detect errors, the main unit... 

OQ should include backup and recovery, data archive and retrieval, security, system administration procedure verification, startup and shutdown, UPS continuity, communications loss and recovery, and systems redundancy challenges such as mirrored drives, secondary systems, and failsafe systems. 

In this case, the integrity of each file is verified by comparing the cross-redundancy check (CRC) of the installed file with the checksum of the original file recorded on the installation master. Modified or corrupt files have different checksums and are, thus, detected by the verification program. Verification reports include a list of missing, changed, and identical files. 

Silicon oil pumps verification of the heat transfer media recycle pump redundancy to ensure that the pumps can replace each other if one of them fails. The test was performed by monitoring the pressure in the pipe before and after failure of a pump. 

One of the most important issues connected with digital I C is common cause failure (CCF). There exists the probability that a latent fault can exist in the system. This fault can be triggered and may propagate throughout the system as shown in Fig. Xll/3.1.1-1. In most software one subprogram/subroutine may be used many times in a full program. Naturally, if there is a fault, then it can be repetitive, and when used even with redundant channels the same mistake may recur. Naturally extra care must be taken to ensure with thorough validation and verification. 

Aerospace has continued to provide many engineering, design, and safety services to the Air Force for more than 40 years. One of its chief functions is to perform launch verification and readiness assessments for all Air Force space launches. Aerospace s launch verification procedure is veiy broad, beginning with analysis of launch system design. Aerospace independently tests physical components and software, checks manufacturing processes, and verifies correct assembly of the launch vehicle. Finally, Aerospace delivers a formal launch verification letter to the Air Force s Space and Missile Systems Center, monitors the launch, and analyzes launch and post-launch data (Tomei, 2003). All of the functions are redundant in the sense that Air Force and contractor personnel also perform most of the same functions. Aerospace s launch verification serves as an independent, objective assessment of launch safety that the Air Force uses in conjunction with its own analyses in making launch decisions. 

An area which has not been considered to be within the scope of this requirement is the mechanical sensing lines of the instrumentation which feed the protection system. Since the sensing lines are essential to the reliable operation of the protection systems, identification of these lines would facilitate verification that sensing lines are appropriately separated and protected from external and internal hazards. In some cases, separation of redundant division instrument sensing lines used for the protection system has not been carried out. 

Reliability of a braking system can be improved by means of applying loo2D redundancy architecture. The architecture is organized as two identical channels. These channels are supplemented with a diagnostics (based on data from an incremental sensor), and a brake controller. Two brake disks are installed on the same shaft. Data obtained from incremental sensors have to be identical. By means of comparison of data from two sensors these sensors can be verified. Two brakes (main and redundant) have to work in turn that allows verification of their operability permanently. Calculation of the redundant scheme is not the target of this paper and it will not be described here in details. However, all calculations were conducted in accordance to formulas of PFH calculation for loo2D architecture (lEC 61508-6 2010). These formulas were converted to time-dependent Equations 6-7 ... 

Administrative barriers are typically used for a prevention of (slow) boron dilution. Most of the plants would have a Technical Specification requirement on the boron concentration and its verification during the shutdown operation. In addition, there is an example of administrative requirement on the minimum permissible redundancy of neutron flux monitoring system detectors. 

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