Manual protection systems

Secondary containment systems are best described as passive protective systems. They do not eliminate or prevent a spill or leak, but they can significantly moderate the impact without the need for any active device. Also, containment systems can be defeated by manual or active design features. For example, a dike may have a drain valve to remove rain water, and the valve could be left open. A door in a containment building could be left open. 

Manually Controlled System A manually controlled system comprises one or more transformer-rectifiers each with its associated control panels which supply the d.c. to the various anodes installed in the water box spaces. Each transformer-rectifier is provided with its own control panel where each anode is provided with a fuse, shunt and variable resistor. These enable the current to each anode to be adjusted as required. Reference cells should be provided in order to monitor the cathodic protection system. In the case of a major power station, one transformer-rectifier and associated control panel should be provided for separate protection of screens, circulating water pumps and for each main condenser and associated equipment. 

A general application of loss prevention practices is considered prudent both by insurers and petroleum companies, so overall, all facilities are required to achieve the corporate protection standards. In fact the premium of insurance is normally based on the level of risk for the facility after an insurance engineer has "surveyed" the facility. Isolated cases may appear where less fixed protection systems are provided in place of manual fire fighting capabilities, however the general level of overall loss prevention level or risk is maintained. Insurers will also always make recommendations for loss prevention improvements where they feel the protection levels are substandard and the risk high. Where they feel the risk is too high, they may refuse to underwrite certain layers of insurance or charge substantial additional premiums for reinsurance requirements. 

Active fire protection systems can be installed to provide the desired mitigation by either manual or automatic activation. 

Open grating floors allow spilled liquids or solids to fall through onto lower levels, possibly resulting in housekeeping problems and personnel exposure to spilled materials. In addition, if cascading liquid is ignited, a three-dimensional fire can result. These three-dimensional fires can be difficult to control by manual firefighting or even with fixed fire protection system. 

In general, fixed water spray fire protection has the two-fold purpose of cooling the affected equipment and flushing any burning liquids from the immediate fire area. This can reduce local damage, limit fire spread, and allow time for other response actions. It should not be expected that these systems will extinguish a fire without the use of other fire protection systems, such as foam, dry chemical, or manual firefighting. 

Fixed fire protection systems for process structures and areas can be activated automatically or manually. Automatic activation provides quicker and more reliable response than is typically possible with manual activation. Vari-... 

Since control rooms are normally constantly manned, it is considered unlikely that a fire could progress undetected to a hazardous size. Fixed fire protection systems, whether manually or automatically activated, are seldom installed in control rooms of processing facilities, mainly due to the fact that they are normally constantly manned. As such, it is considered unlikely that any fire that does occur would progress undetected to a size that cannot be extinguished by manual intervention (fire extinguishers, hose reel, etc.). 

Burns, L.A. Cline, D.M. Lassiter, R.R. "Exposure Analysis Modeling System (EXAMS) User Manual and System Documentation" U.S. Environmental Protection Agency, Environmental Research Laboratory Athens, GA, 1981. 

Validation test environment including hardware, software System security including passwords, network rights, functional security, physical security, modem access and virus protection Validation test environment including related documents, along with standard operating procedures, user manuals, and system development/ maintenance and documentation Validation assumptions, exclusions, and limitations Responsibilities matrix Validation data sets Acceptance criteria Expected results Execution of the validation plan Resolution of errors Documentation Training records... 

The fire protection system consists not only of a deluge system activated by the ultraviolet sensors, but also of fusible link type fire systems. The deluge system has a trip mechanism from mercury checks activated by heat-activated-devices, a manual release on the deluge valve, a pneumatic remote trip station, and an electrical push button along with the electrical trip mechanism from the U/V detectors. The remote trip stations are located by escape routes so it is possible for the operator to trip the systems as he exits the building without exposing himself to further danger. 

Type-3 technologies require active control to mitigate a disturbance and consequently are protective systems associated with the process flowsheet. Notice that certain control actions cannot be modeled easily without overspecifying the system such as the manual override of the quench valve by the operator. For this reason, the constraint list, as described earlier, is associated with each piece of process equipment. This allows us to associate in an a posteriori manner additional control structures that are available to the process. 

Fire Protection Systems Inspection, Test, and Maintenance Manual Wayne G. Carson and Richard L Klinker, National Fire Protection Association, Item No. NB-FPS-93,230pages, 49.50. 

This manual Includes detailed descriptions on all types of fire protection systems NFPA, BOCA. andOSHA requirements recommended practices from major insurance companies and a listing of equipment manufacturers. 

The sources for this discussion are experts at the U.S. Army Chemical and Biological Defense Command,34 and Collective Protective Equipment, U.S. Army Training Manual 34240-338-10,35 which interested readers can consult for greater detail. Medical Collective Protection Systems... 

Fire Service Features of Buildings and Fire Protection Systems Explains how fire service operations can be influenced by different building features and offers considerations for design professionals that can help facilitate these operations. The manual includes chapters and narratives on building and site design, sprinkler systans, standpipe systems, fire department connections, fire alarm and conununications systans, as weU as various firefighting systems (OSHA 3256— 2006). 

The design of the plant should be tolerant of human error. To the extent practicable, any inappropriate human actions should be rendered ineffective. For this purpose, the priority between operator action and safety system actuation should be carefully chosen. On the one hand, the operator should not be allowed to override reactor protection system actuation as long as the initiation aiteria for actuation apply. On the other hand, there are simations where operator interventions into the protection system are necessary. Examples are manual bypasses for testing purposes or for adoption of acmation criteria for modifications to the operational state. Furthermore, the operator should have an ultimate possibility, under strict administrative control, to intervene in the protection system for the purposes of managing beyond design basis accidents in the event of major failures within the reactor protection system. 

The Reactor Protection System (RPS) is an overall complex of instrument channels, trip logic, trip actuators, manual controls, and scram logic circuitry that initiates the rapid insertion of control rods by hydraulic force to scram the reactor when unsafe conditions are detected. The RPS uses the functions of the essential multiplexing subsystem (EMS) and the SSLC system to perform its functions. 

The System 80+ Standard Design is designed to preclude water spray from the fire protection system onto safety-related equipment. The sprinkler systems protecting the safety-related equipment is of the automatic sprinkler type. Actuation of these sprinkler systems requires the opening of the fusible link sprinkler heads and detection by combustible-products and/or heat detectors. In addition, the operator has the capability of isolating flow from the control room by isolating the Sub-sphere Building headers or, locally by manual isolation valves. 

The EFW system is actuated automatically by an emergency feedwater actuation signal (EFAS) from the ESF actuation system or by the auxiliary protection system (described in CESSAR-DC Section 7.7). In addition to this automatic feature, the EFWS can be manually initiated as described in CESSAR-DC Section... 

The nuclear system protection system initiates the rapid insertion of the control rods to shut down the reactor. The system is of the fail-safe design where it will trip on loss of electrical power but will not trip and cause a scram on the loss of a single power source. The four trip channels are physically separated from each other and from other equipment precluding the possibility of interactions that could cause possible false scrams or failure to scram. The logic requires a manual reset by the operator, which is automatically inhibited for 10 s. One reset switch is used for each trip channel. Failure of a single trip channel, division logic, or a system component will not prevent the normal protective action of the nuclear system protection system. 

In filter tanks, a pipe (at least DN15) with a test valve must be placed beneath the exhausters leading to the floor level through which water must be taken to the open air every day until the water is free from gas bubbles (see Fig. 20-4b). The partly filled cathodically protected pressure booster tank cannot be provided with automatic gas exhausters. Therefore, nozzles (at least DN15) with manually operated valves must be provided at the highest point of the tank. Before emptying, the protection system must be switched off and the tank filled with water through the manual valve. 

The first two layers are described in section 3.1 and 3.2. Apart fi om these control layers the plant is protected against excursions outside the operating boimdaries by an Alarm Management system and an Instrumented Protective System (IPS). The Alarm Management system warns the operators to take manual action in case the plant moves outside the allowed operating window. The IPS system is fully independent fi om the control and alarm system and can automatically shut down (parts ol) the plant in a safe manner. 

---