Service inspection

Lecoeur-Taibi, I., Calmon, P., Lasserre, F., Mathonnet, H., "Mephistomis an ultrasonic modeling tool for defects analysis during in-service inspections", Proc. 14th hit. Conf. NDE Nucl. Pres. Ves. Ind., 1996, 605-608. 

In service inspections of French nuclear Pressure Water Reactor (PWR) vessels are carried out automatically in complete immersion from the inside by means of ultrasonic focused probes working in the pulse echo mode. Concern has been expressed about the capabilities of performing non destructive evaluation of the Outer Surface Defects (OSD), i.e. defects located in the vicinity of the outer surface of the inspected components. OSD are insonified by both a "direct" field that passes through the inner surface (water/steel) of the component containing the defect and a "secondary" field reflected from the outer surface. Consequently, the Bscan images, containing the signatures of such defects, are complicated and their interpretation is a difficult task. 

Up-to-day reliability requirements as applied to NPP strength maintenance govern development of new generation of computerized systems for in-service inspection. These systems in parallel with capabilities of ordinary ultrasonic techniques allow to reconstruct high resolution image of inner flaw and increase available amount of information. 

The use of Lamb waves offers the possibility of rapid long-range in-service inspection. Receiver and transmitter probes are positioned single sided - access is only required from one side of the specimen - in a pitch-catch-arrangement, the receiver being outside tbe field of the specular reflection. 

In-service Inspection by X-Ray Tomosynthesis, A New Method for Sizing IGSCC. 

Risk-Based Inspection. Inspection programs developed using risk analysis methods are becoming increasingly popular (15,16) (see Hazard ANALYSIS AND RISK ASSESSMENT). In this approach, the frequency and type of in-service inspection (IS I) is determined by the probabiUstic risk assessment (PRA) of the inspection results. Here, the results might be a false acceptance of a part that will fail as well as the false rejection of a part that will not fail. Whether a plant or a consumer product, false acceptance of a defective part could lead to catastrophic failure and considerable cost. Also, the false rejection of parts may lead to unjustified, and sometimes exorbitant, costs of operation (2). Risk is defined as follows ... 

Maintenance embraces regular inspection, periodic examination by competent persons , and repairs. Accidents may arise as a result of the lack of maintenance, during maintenance, and as a consequence of faulty maintenance. Preventive maintenance can be a legal requirement for, e.g., pressure vessels/boilers, lifting gear, power presses. A system is required for monitoring compliance witli scheduled preventive maintenance programmes, backed up by in-service inspection. Breakdown... 

Thomas, H. M., 1979, In-Service Inspection is Over-Rated, Inst. Nucl. Eng., /. 46 ... 

How do you ensure that the design, production process, installation, servicing, inspection, and test procedures and applicable documentation are compatible with the specified requirements ... 

The aforementioned reviews and assessments were assimilated to characterize the effect of dielectric, rotational, and mechanical hazards on motor performance and operational readiness. Functional indicators were identified that can be monitored to assess motor component deterioration caused by aging or other accidental stressors. The study also includes a preliminary discussion of current standards and guides, maintenance programs, and research activities pertaining to nuclear power plant safety-related electric motors. Included are motor manufacturer recommendations, responses from repair facilities to a questionnaire, in-service inspection data, expert knowledge, USNRC-IE audit reports, and standards and guides published by the Institute of Electrical and Electronics Engineers (IEEE). 

The majority of the independent engineering inspection authorities now provide a wide range of engineering inspection services quite apart from the in-service inspections of insured plant. These services are available to industry at large and, although widely used by presently insured clients, they are frequently employed by organizations that have no specific insurance or inspection involvement with the chosen engineering inspection authority. 

Food Safety and Inspection Service (FSIS) sets standards for food safety and inspects meat, poultry, and egg products produced domestically and imported. The Service inspects animals and birds at slaughter and processed products at various stages of the production process, and analyzes products for microbiological and chemical adulterants. FSIS also informs the public about meat, poultry, and egg product food safety issues. FSIS works with the Research, Education and Economics mission area on food safety research issues and the Animal and Plant Health Inspection Service on instances where animal diseases impact food safety. FSIS also facilitates the management of US activities pertaining to the Codex Alimentarius Commission, an international organization created by the United Nations, to promote the health and economic interests of consumers while encouraging fair international trade in food. 

To provide routine facilities, services, inspections, and control activities at designated international airports, ports, and ground crossings to prevent the international spread of disease... 

Unites States Congress passes Drug Importation Act that allows United States Customs Service inspection to stop entry of foreign drugs. 

Maintenance Superior. In-service inspection easier as a result of better access to heat exchangers and piping. Service work simpler as a consequence of improved access and lower temperature. 

The painting crew used a 5-ft. diameter by 6-ft. tall, portable, vertical, pressure vessel which was designed for 125 psig (860 kPa gauge) internal pressure. After a routine fit for service inspection, the industrial-sized vessel and trailer were brightly painted. A decision was made to renew the hardware on the top-mounted, ten-inch charging nozzle. 

Visual external inspections (or in-service inspections) should be made regularly to operating vessels to help ensure the integrity of the vessel. The frequency of this inspection should... 

The Dow Freeport inspection program included an annual visual inspection while the vessel is in operation. Dow schedules the initial out-of-service (or internal) inspection within the first five years a vessel is in service and subsequent internal inspections are performed at least every five years thereafter. If either the owner or the inspector believe it is necessary for more frequent in-service and out-of-service inspections, the schedule is adjusted to accommodate that need. The Pressure Vessel Review Section (PVRS) can extend the frequency of internal inspections up to once in ten years, if sufficient data support this conclusion. [19]... 

The Dow Freeport in-service inspection procedures are similar to those reported earlier in this chapter. The Dow out-of-service (internal) inspection includes ultrasonic thickness measurements at all benchmark locations. Other test methods include shear wave ultrasonics, eddy current, and radiography. Engineers use ultrasonic thickness readings to project the remaining useful life of the vessel and to determine when the next internal inspection should be scheduled. 

During service inspection corrosion of an upper surface wing panel containing an access door was observed. The panel and door were made from an alloy plate to which aluminum catches were attached for securing the door in the closed position. Stainless shims were fitted between the catches and the aluminum plate. 

Visual external inspections (or in-service inspections) should be made regularly to operating vessels to help ensure the integrity of the vessel. The frequency of this inspection should be site-specific, between semiannually and once every three years for most chemical plant processes, depending on the aggressiveness of the chemical plant atmosphere. However, API 510 will accept intervals up to once every five years. 

XI Rules for in-service inspection of nuclear power plant components... 

S. Selection of chemical processing materials which are not prone to irradiation damage and do not have objectionable corrosion properties. This latter point is very important since servicing, inspection, and replacement of plant equipment containing high levels of radioactivity is a very costly and dangerous procedure. 

When the column was previously in service, inspection by backlighting may reveal internal blockages in mist eliminators and similar internals, even when the device appears visually clean (335). 

Lock, M. W. B., and Strutt, J. E. (1985), Reliability of In-Service Inspection of Transport Aircraft Structures, CAA Paper 85013, Civil Aviation Authority, London. 

Structure containing likely damage or defects that are not detectable during manufacturing inspections and service inspections must withstand Ultimate Load and not impair operation of the aircraft for its lifetime (with appropriate factor). 

This chapter starts with a brief overview of composite damage situations. This is followed by a description of the major NDT methods applied to composite structures during manufacturing and in-service inspection. 

Additional protection will be afforded by improved methods of non-destructive in-service inspection to demonstrate the integrity of sodium vessels and pipework and to detect incipient defects so that they can be repaired before they grow to cause leaks. Ultrasonic methods for inspecting welds in austenitic steels, and transition welds between steels of different composition, have been improved and further improvement can be expected. Components will increasingly be designed to facilitate in-service inspection. 

These mechanisms are mainly derived from the Superphenix DSD mechanisms, so it has to accommodate the results of in-service inspection and maintenance works on the DSD mechanisms and the DSD absorber rods at Superphenix. 

In-service inspection (ISI) is an important means to assess structiual integrity and needs attention in design in particular, for main vessel SG. 

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