IEEE 1819:2016 pdf free download – IEEE Standard for Risk-lnformedCategorization and Treatment of Electrical and Electronic Equipmentat Nuclear Power Generating Stationsand Other Nuclear Facilities
reasonable confidence: A level of confidence based on facts, actions, knowledge, experience, and/or observa-tions, which is deemed to be adequate.Reasonable confidence is a lower level of confidence than reasonableassurance.
risk: Probability and consequences of an event, as expressed by the answer to the following three questions: 1)What can go wrong? 2)How likely is it? and 3) What are the consequences if it occurs?
Risk-Informed Safety Classification -1(RISC-1):Electrical and clectronic systems and components (EE-SCs) that are Class 1E and that the risk-informed categorization process determines are significant contribu-tors to plant safety.RISC-1 EESCs perform their safety-significant functions consistent with the categoriza-tion process, including those safety-significant functions that go beyond the functions defined as Class 1E forwhich credit is taken in the categorization process.(EESCs that are Class 1E and perform safety-significantfunctions.)
Risk-Informed Safety Classification -2(RISC-2): Electrical and electronic systems and components (EE-SCs) that are defined as non-Class 1E, although the risk-informed categorization process determines that theyare significant contributors to plant safety on an individual basis.Though some RISC-2 EESCs may not haveexisting special treatment requirements, the focus forRISC-2 EESCs is on the safety-significant functions forwhich credit is taken in the categorization process.(EESCs that are non-Class lE and perform safety-signifi-cant functions.)
Risk-Informed Safety Classification -3(RISC-3): Electrical and electronic systems and components (EE-SCs) that are defined as Class 1E, although the risk-informed categorization process determines that they arenot significant contributors to plant safety. Special treatment requirements may be reduced for RISC-3 EESCsand replaced with alternate treatments. These alternate treatments are intended to provide reasonable confi-dence that theseEESCs can perform their Class 1E functions under design-basis conditions, albeit at a reducedlevel of assurance compared to the current special treatment requirements.(EESCs that are Class 1E and per-form low safety-significant functions.)
Risk-Informed Safety Classification -4(RISC-4): Electrical and electronic systems and components (EE-SCs) that are defined as non-Class 1E, and that the risk-informed categorization process determines are notsignificant contributors to plant safety.(EESCs that are non-Class 1E and perform low safety-significantfunctions.)
safety significant:Syn.: high safety significant.
safety significant function: A function whose degradation or loss could result in a significant adverse effecton defense-in-depth, safety margin, or risk.
sensitivity studies:Analyses that are performed to verify that assumptions or uncertainties made in the proba-bilistic risk assessment are not masking the importance of an electrical and clectronic system and component.Typical sensitivity studies include increasing human error rates, removal of common cause failures, increasingmaintenance unavailabilities, and increasing the failure rate of low safety significant components.
special treatment requirements: Current regulatory requirements imposed on structures, systems, and com-ponents that go beyond industry-established(industrial) controls and measures for equipment classified ascommercial grade and are intended to provide reasonable assurance that the equipment is capable of meetingits design basis functional requirements under design basis conditions. These additional special treatmentrequirements include design considerations, qualification, change control, documentation, reporting, mainte-nance, testing, surveillance,and quality assurance requirements.
testing: The act of verifying that componcnt performance satisfies expected results or parameters.