Filtered Containment Venting System (FCVS) for removal of elemental and organic iodine during severe nuclear power plant accidents

Structural integrity may be threatened due to over pressurization by accumulation of steam and noncondensable gases in a scenario of `beyond design basis accident' leading to a situation of potential fission product release to the environment. Filtered Containment Venting System (FCVS) has been considered for depressurization while keeping off-site doses low or within prescribed limits. Various types of FCVS have been installed on many nuclear power plants world-wide. In case of a nuclear meltdown accident followed by an over-pressurization that may require venting, the mixture of steam and non-condensable gases containing iodine is passed through the FCVS. Radioactive iodine in various organic and inorganic forms is scrubbed in a specific scrubbing solution while the cleaned steam-gas mixture can then be discharged into the environment. Among the spectrum of fission nuclides generated as a result of fission, iodine with its nine oxidation stages is perhaps the most reactive fission product generated and released into the primary coolant system during the event of severe NPP accidents. Because of fuel degradation and melting, a huge inventory of iodine is volatilized. Understanding of iodine behavior in environment similar to that of containment is necessary prerequisite for planning effective mitigation system for efficient retention of iodine within containment boundary. The prevailing conditions i.e. iodine concentration, pH, temperature and dose rate will govern the iodine behavior in the sump water as well as in the containment. Development of an efficient, fast and reliable mechanism to retain volatile iodine species in a containment of a nuclear reactor during a severe accident has been an active area of research in the recent years. The need for such research is greatly enhanced in Post Fukushima nuclear era. This paper reviews the available FCVS options and specifically outlines the related research and development activities being carried out at Pakistan Institute of Engineering & Applied Sciences (PIEAS)

Production and the quality control for the CMS endcap RPCs

The production for the endcap RPCs in the CMS experiment has entered a mature stage of the production stream. In this paper, the production facilities and the selection procedures of the qualified RPC gaps axe presented. The mass production and the quality control tests for the endcap RPCs have reached the maximum productivity. The yield to produce the qualified gaps is now above 80% of the qualified bakelite sheets provided by Italy. We also report an intensive aging study for the endcap RPCs performed by using a 200 mCi Cs-137 gamma-ray source. A few diagnostic methods to observe aging phenomena are discussed. The test result is equivalent to approximately 12 years of Compact Muon Solenoid (CMS) RPC operation.Physics, Particles & FieldsSCI(E)CPCI-S(ISTP)

The RPC system for the CMS experiment

The CMS experiment at the CERN Large Hadron Collider (LHC) is equipped with a redundant muon trigger system based on Drift Tubes Chambers (DT) and Cathode Strip Chamber (CSC), for the precise position measurement, and Resistive Plate Chambers (RPC), for the bunch crossing identification and a preliminary fast measurement of the muon transverse momentum. The CMS RPC system is constituted by 480 chambers in the barrel and 756 chambers in the forward corresponding to a total surface of about 3500 m2. The design and construction has involved many laboratories scattered all over the word. An accurate quality control procedure has been established at different levels of the production to achieve final detectors with operation parameters well inside the CMS specifications. In the summer 2006 a preliminary slice test involving a fraction of the CMS detector was performed. The performance of the RPC system with cosmic rays was studied versus the magnetic field using final running hardware and software protocols. Results on the RPC main working parameters are reported. © 2006 IEEE

CMS physics technical design report, volume II: Physics performance

CMS is a general purpose experiment, designed to study the physics of pp collisions at 14 TeV at the Large Hadron Collider ( LHC). It currently involves more than 2000 physicists from more than 150 institutes and 37 countries. The LHC will provide extraordinary opportunities for particle physics based on its unprecedented collision energy and luminosity when it begins operation in 2007. The principal aim of this report is to present the strategy of CMS to explore the rich physics programme offered by the LHC. This volume demonstrates the physics capability of the CMS experiment. The prime goals of CMS are to explore physics at the TeV scale and to study the mechanism of electroweak symmetry breaking - through the discovery of the Higgs particle or otherwise. To carry out this task, CMS must be prepared to search for new particles, such as the Higgs boson or supersymmetric partners of the Standard Model particles, from the start- up of the LHC since new physics at the TeV scale may manifest itself with modest data samples of the order of a few fb(-1) or less. The analysis tools that have been developed are applied to study in great detail and with all the methodology of performing an analysis on CMS data specific benchmark processes upon which to gauge the performance of CMS. These processes cover several Higgs boson decay channels, the production and decay of new particles such as Z' and supersymmetric particles, B(s) production and processes in heavy ion collisions. The simulation of these benchmark processes includes subtle effects such as possible detector miscalibration and misalignment. Besides these benchmark processes, the physics reach of CMS is studied for a large number of signatures arising in the Standard Model and also in theories beyond the Standard Model for integrated luminosities ranging from 1 fb(-1) to 30 fb(-1). The Standard Model processes include QCD, B-physics, diffraction, detailed studies of the top quark properties, and electroweak physics topics such as the W and Z(0) boson properties. The production and decay of the Higgs particle is studied for many observable decays, and the precision with which the Higgs boson properties can be derived is determined. About ten different supersymmetry benchmark points are analysed using full simulation. The CMS discovery reach is evaluated in the SUSY parameter space covering a large variety of decay signatures. Furthermore, the discovery reach for a plethora of alternative models for new physics is explored, notably extra dimensions, new vector boson high mass states, little Higgs models, technicolour and others. Methods to discriminate between models have been investigated. This report is organized as follows. Chapter 1, the Introduction, describes the context of this document. Chapters 2-6 describe examples of full analyses, with photons, electrons, muons, jets, missing E(T), B-mesons and tau's, and for quarkonia in heavy ion collisions. Chapters 7-15 describe the physics reach for Standard Model processes, Higgs discovery and searches for new physics beyond the Standard Model

CMS physics technical design report, volume II: Physics performance

CMS is a general purpose experiment, designed to study the physics of pp collisions at 14 TeV at the Large Hadron Collider ( LHC). It currently involves more than 2000 physicists from more than 150 institutes and 37 countries. The LHC will provide extraordinary opportunities for particle physics based on its unprecedented collision energy and luminosity when it begins operation in 2007. The principal aim of this report is to present the strategy of CMS to explore the rich physics programme offered by the LHC. This volume demonstrates the physics capability of the CMS experiment. The prime goals of CMS are to explore physics at the TeV scale and to study the mechanism of electroweak symmetry breaking - through the discovery of the Higgs particle or otherwise. To carry out this task, CMS must be prepared to search for new particles, such as the Higgs boson or supersymmetric partners of the Standard Model particles, from the start- up of the LHC since new physics at the TeV scale may manifest itself with modest data samples of the order of a few fb(-1) or less. The analysis tools that have been developed are applied to study in great detail and with all the methodology of performing an analysis on CMS data specific benchmark processes upon which to gauge the performance of CMS. These processes cover several Higgs boson decay channels, the production and decay of new particles such as Z\u27 and supersymmetric particles, B-s production and processes in heavy ion collisions. The simulation of these benchmark processes includes subtle effects such as possible detector miscalibration and misalignment. Besides these benchmark processes, the physics reach of CMS is studied for a large number of signatures arising in the Standard Model and also in theories beyond the Standard Model for integrated luminosities ranging from 1 fb(-1) to 30 fb(-1). The Standard Model processes include QCD, B-physics, diffraction, detailed studies of the top quark properties, and electroweak physics topics such as the W and Z(0) boson properties. The production and decay of the Higgs particle is studied for many observable decays, and the precision with which the Higgs boson properties can be derived is determined. About ten different supersymmetry benchmark points are analysed using full simulation. The CMS discovery reach is evaluated in the SUSY parameter space covering a large variety of decay signatures. Furthermore, the discovery reach for a plethora of alternative models for new physics is explored, notably extra dimensions, new vector boson high mass states, little Higgs models, technicolour and others. Methods to discriminate between models have been investigated. This report is organized as follows. Chapter 1, the Introduction, describes the context of this document. Chapters 2-6 describe examples of full analyses, with photons, electrons, muons, jets, missing E-T, B-mesons and tau\u27s, and for quarkonia in heavy ion collisions. Chapters 7-15 describe the physics reach for Standard Model processes, Higgs discovery and searches for new physics beyond the Standard Model

CMS : the TriDAS Project Technical Design Report; v.1, the Trigger Systems

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