Pakistan Research Reactor-1 (PARR-1) has been converted to low enriched uranium (LEU) fuel and upgraded to a maximum power level of 9MW. During conversion and upgradation most of the reactor systems were modified and several additional facilities were provided. Major changes were carried out in the cooling system. These include installation of new primary pumps, set of heat exchanger assemblies, a cooling tower and piping system. Vibration tests on these systems were performed to check the integrity and detect any abnormality in normal operation. Results of the tests performed on the primary pumps and core support structure comply with the requirements for pre-operational and initial startup vibration testing of nuclear power plant (NPP) system. Attempt is now being made to analyze vibrations of primary piping.The Primary Water Inlet Pipeline (PW-IPL) is of stainless steel conveying demineralized water from holdup tank to the reactor pool. The section of the pipeline from heat exchangers to the valve pit is hanger supported, and the rest from valve pit to the reactor pool is embedded. Vibration of the PW-IPL may be categorized into steady state and transient. The reactor pumps mainly contribute the steady state vibrations, while transient vibrations arise due to instant closure of check valves (water hammer). The ASME Boiler and Pressure Vessel code provides data only about the limits of'acceptable vibrations and stresses related to the primary static stress due to steady state vibrations. However, due to complexity and diversity in the pipe structure, stresses related to the transient vibrations are neglected in the code.In this paper steady state and transient vibration behavior of PW-IPL of PARR-1 has been analyzed. In the analysis vibration data was used for comparison with the allowable limits, estimations of pressure wave velocity, deflection, natural frequency, tensile and shear load on hanger support, and to obtain the ratio of maximum combine stress to the allowable.
Background This study reflects the pattern of road traffic accidents and road traffic injuries sustained by RTA victims reporting to LRH MTI. Traffic volume, single and narrow roads is a big problem, traffic rules violation is another demon, lack of awareness, reluctance for the use of safety gears, underage vehicle drivers or rider with questionable driving/ riding skills and no license has worsen the injury pattern and more severe crashes here, putting pedestrians and biker at high risk. Aim: To know the different trends of road traffic accidents, most common victims and different patterns of injuries Methods This is hospital based analytical comparative study, which was conducted in the trauma section of Accident Emergency lady reading hospital MTI Peshawar KPK, during the tenure from May 2020 to November 2020. In this study 298 victims of road traffic accidents were assessed and analyzed from both genders and of all age groups. Results 298 victims of RTAs evaluated in our study. Most common mechanism involved pedestrian verses vehicle 40.3% followed by vehicle versus vehicle 28.6%, curiously in 5.3% of RTAs mechanism was unknown. Most of victims were males when compared with females, Males 86.3% and females 13.6%. children age group 0 -10 years makes 12.6%. Most common vehicle involved was a bike in 48%, followed by car 30% and then 3-wheelers (auto ricksha and Qing chi) 15.3% followed by crashes involving unknown vehicle 8% which is significantly high with all the victims severely wounded or unknown category. Most common victims were vulnerable road users (pedestrian and bike riders) 35% pedestrians and 31.6% bike riders. 11.3% of victims were passengers. Most common injury sustained was head injury38.5%(n=115), followed by lower limb injuries(n=105) 35.2% and polytrauma victims with chilling percentage of 9.3%. Conclusion There is a rising toll of road traffic injuries in and around Peshawar and majority being reported to emergency department LRH, MTI and it is major public health concern. Not only Pedestrians and bike rider are at threat but children of age group under 10 as well with high pedestrian mortality. If proper preventive steps not taken this will continue to rise causing significant death and disabilities. Keywords: Road traffic injuries, road traffic accidents, safety gears road traffic injury victims
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