4
TH ST Workshop CHAMONIX
| Session: | LHC & Experimental Areas |
| Chairmen: | Jean-Luc Baldy (Session 1) & Mats Wilhelmsson (Session 2) |
| Duration of session: | 375 min. (presentations 255 min., discussions 120 min.) |
| Powering the Transfer Lines TI2 and TI8 |
| Abstract Electrical power for the transfer tunnels will be distributed from the LHC side and the SPS side. For the injection tunnel TI2, buildings LHC SR2, SPS BA6 and BA7 will be used to house the power converters and MV/LV switchboards. Galleries and ducts will facilitate cabling between power transformers and converters. For TI8, buildings LHC SR8 and SPS BA4 will be used. MBI magnets will be powered by water-cooled cables whilst rest of the magnets will be powered by conventional copper and aluminium cables. A load of 16.15 MVA and 30 MVA was intended for the existing SPS 18 kV pulsed loop by TI2 and TI8 respectively. The main compensator associated with this loop will almost reach its capacity with the load of TI2 alone. Therefore a new 18 kV pulsed link from Prevessin to BA4 will be installed, compensated by the third compensator. This paper explains how the above tasks will be achieved. |
| Non-destructive Testing of Pipelines |
| Abstract This paper shall present different, contemporarily available non-destructive testing (NDT) methods of pipelines and compare them to each other from the technical and economical point of view. An evaluation of their suitability for CERN activities, based on the opinions and experience of various specialists at CERN (LHC, ST, TIS), is also introduced. |
| Control System Implementation and Follow-up within the Cooling and Ventilation Contracts for the LHC |
| Abstract The control system implementation for the cooling and ventilation facilities connected to the LHC Project relies on the technical and human resources that are organised within large-size industrial contracts. Beside the technical aspects, the follow-up of the implementation activities in the framework of such contracts also involves a managerial effort in order to achieve a flexible and coherent control system. The purpose is to assure precise and reliable regulation together with accurate local and remote supervision in conformity with the operational requirements. These objectives can only be reached by a systematic approach that keeps the co-ordination between the in-house and external cross-disciplinary teams as well as the fulfilment of the validation procedures and the contractual formalities. The case that here illustrates this approach is the control system implementation for the heating, ventilation and air conditioning of the LHC surface buildings, which shall extend up to 2004. |
| Avancement des travaux électriques LHC point 1 |
| Abstract Après la première phase d’analyse des principes de la distribution en électricité de la zone 1 du LHC et de l’expérience ATLAS, les études sont à présent orientées vers la définition des implantations des principaux équipements tels que transformateurs, tableaux basse tension, alimentations statiques de sécurité, ainsi que vers la détermination du cheminement des câbles dans les ouvrages de surface et à travers les ouvrages souterrains USA15, UX15 et les galeries de liaison. Les études des services généraux sont également menées pour les bâtiments de surface qui seront mis prochainement à disposition par le génie civil, en particulier la station de refroidissement SF1 ainsi que le bâtiment SUX1 pour lesquels les travaux d’installation devraient débuter sous peu pour être achevés dans le premier trimestre 2001. |
| LHC Progress Report & Perspectives |
| Abstract |
| ST LHC Budget Follow-up |
| Abstract The ST division is deeply implicated in the LHC project, with a budget of more than 20% of the overall cost of the project. It is therefore important to monitor future estimates, the actual situation and to see where there are divergences between the two. A database has been created presenting the figures for each contract, group, and for the division as a whole. Despite the various types of contract management, the system presents the results in a uniform manner. It allows the initial, present and future situations to be easily reviewed. This highlights any problem areas, facilitates decision-making and enables us to inform the hierarchy of any changes that may have occurred. |
| Câblage des expériences LHC |
| Abstract Le câblage d’un détecteur se compose de deux parties qui demandent des outils et des méthodes d’approche distinctes. D’une part, le câblage externe du détecteur comprenant typiquement les liaisons entre les racks situés dans les cavernes de service et les patchs de jonction et d’autre part le câblage interne du détecteur comprenant toutes les liaisons qui y entrent. Le câblage est abordé d’un point de vue industriel selon l’approche mise en oeuvre pour un accélérateur. En utilisant les méthodologies de travail et les outils informatiques de ST-EL, il est possible de réaliser une partie de l’installation des câbles dans cette zone. Ce document en explique l’application, aborde les limites des méthodes et des outils, ainsi que les interfaces entre les divisions EP, EST et les expériences. |
| CMS Experiment and ST Division |
| Abstract CMS is now in full construction at point 5. Present status will be shown and explained. Various ST groups are engaged in the infrastructure and services projects in direct contact with the CMS Technical Coordination Group, EST-LEA, and the Experimentalists. To streamline these activities ST has nominated a ST Coordinator for CMS activities inside the Division. The beneficial influence of this novel structure will be reviewed from the CMS side. |
| Strategy for the Operation of Cooling Towers with variable Speed Fans |
| Abstract Within the SPS Cooling Water Project at CERN aimed at the reduction of water consumption, this primary open cooling loop will be closed and all the primary cooling circuit components will be upgraded to the new required duty and brought to the necessary safety and operability standards. In particular the tower fans will be fitted with variable frequency drives to replace the existing two speed motors. This paper presents a study to optimize the operation of SPS cooling towers taking into account outdoor conditions (wet and dry bulb temperatures) and the entirety of the primary circuit in which they will operate. |
| ALICE |
| Abstract |
| Avancement des tavaux électriques LHC point 5 |
| Abstract Au fur et à mesure de la mise à disposition des différents ouvrages de surface, le service électrique ST/EL installe l'éclairage et la petite force suivant le planning défini par la division. Actuellement, les services généraux des bâtiments SY5, SH5, SF5 et SX5 entre les travées 5 et 13 sont terminés. La première partie de la galerie technique est équipée en chemins de câbles et éclairage. Toutes ces installations sont actuellement alimentées par des départs provisoirs en attendant la mise en services de la nouvelle sous-station. Le tableau BT et le transformateur pour l'alimentation des installations ST/CV du bâtiment SF5 sont commandés. La nouvelles sous-station électrique qui sera installée en SE/SR5 est en cours d'étude, une partie du matériel est commandé. Le démontage du SR5 se fera dès le début de l'arrêt du LEP pour permettre d'alimentation des compresseurs CRYO et des installation de refroidissement dans le SF5 début avril. |
| Traitement d'air du tunnel LHC |
| Abstract Le LHC sera le prochain accélérateur du CERN. Il sera basé sur la technologie des aimants supraconducteurs et installé à la place de la machine LEP existante, dans ce même tunnel de 26,7 km, à une profondeur moyenne de 100 m. Si l’enveloppe de ce tunnel est sujette à des modifications mineures, la nouvelle technologie projetée présentera des contraintes significatives : encombrement, charges internes, présence de nouveaux fluides, contrôle d’accès restreint et procédure INB liée à la sécurité. Il en résulte la nécessité d’adapter les installations de ventilation existantes aux nouvelles conditions d’aménagement et de sécurité, et ce pour toute la durée du projet. Dans ce but, le groupe ST-CV du CERN travaille actuellement à l’élaboration d’un nouveau cahier des charges, qui devrait déboucher cette année sur le lancement d’un appel d’offres. Les différents travaux à réaliser s’étendront de la modification et l’extension des installations de traitement d’air existantes à la reconfiguration du système de contrôle, en passant par la rénovation des composants vétustes. |
| Construction Progress of the Cooling & Ventilation in the LHC Project |
| Abstract The Cooling and Ventilation Group has started the LHC construction work in September 1999 and will get into full activity when LEP will be stopped and dismantled: in total 12 major contracts for an amount of about 120 MCHF will be established to build the needed installations for the LHC. The author will report on the current works that are in progress on the different LEP Points distinguishing between the Ventilation and the Water Cooling installations. The Ventilation work, completed in the new surface buildings in Points 18, is currently held in Points 4 and 5. Point 1 will follow in the near future. The work for the Cooling plants comprehend the pumping stations, the cooling towers and the chilled water production stations in Points 1 and 5, the buried pipes in Points 1 and 4. For all of these activities, an updated report of the progress of the work, of the planning and of the expenses is given. Finally, a short overview of the future activities is presented. |
| Fire and Gas Detection in the LHC Experiments - The Sniffer Project |
| Abstract The LHC experiments, due to their complexity and size, present many safety challenges. Cryogenic gases are used in large quantities as well as certain flammable mixtures. The electrical power involved calls for analysis of the fire risks. Access is restricted to the minimum and environmental conditions are extremely harsh, due to strong magnetic fields and ionising radiation. This paper will describe the Combined Fire/Gas/Oxygen deficiency Detection systems proposed for inside the ATLAS and CMS Experiments and possibly for the two others, if they deem it necessary. The requirements of the experiments and the development and implementation of such a system will be discussed. In parallel, commercial procedures to implement these systems by industry shall be described, taking into consideration that a previous development has already been undertaken by CERN for the LEP experiments. The stage is set for inter-divisional collaboration in a project of utmost importance for the safety of people and protection of the investment. |
| Civil Engineering Dispute Resolution |
| Abstract Construction work on the civil engineering contract started at Point 5 in August 1998. The new surface buildings and underground structures are necessary to accommodate the CMS detector for the LHC Project. The principal underground works consist of two new shafts, two parallel caverns separated by a supporting pillar, and a number of small connection tunnels and service galleries. A dispute resolution procedure has been included in the contract, whereby a Panel of Adjudicators may be called upon to make a decision in the case of a difference or dispute between the parties. The aim of this paper is to present CERN’s first experience of civil engineering Adjudication arising from problems encountered with the ground freezing technique employed to allow construction of two new shafts. |
| Progress of the Electrical Installation Work for LHC |
| Abstract During the year 2000 the ST-EL group has performed a number of electrical installations within the LHC project. The 18 kV substation of zone 18 has been entirely renovated and the installations in the SD, SMA and SHM buildings terminated. In access point 5 the SX, SY, SH and SF buildings are either completed or have seen the installation advance according to schedule. The preparations for the injection tunnels and the buildings BA 4 and BA 7 have continued. The study work for the LHC general service is progressing well, supported by a study office, staffed by contracted personnel. The possibilities for an ST-EL support for the cabling of the experiments is currently being investigated by a joint EST – ST working group. A new activity to be taken over by the group is the optical fibre installation. The specialist team from SL joined the group the first of January 2001 and is presently settling in ST. |
| CAD and Engineering Data Management -our Vision |
| Abstract |
| The Status of Common ATLAS/ST Projects |
| Abstract |
| ST Support for LHC Experiments |
| Abstract A couple of years ago, ST division created a first structure for the support of the LHC experiments, aiming to co-ordinate all the activities which traditionally were in the divisional mandate, like civil engineering, cooling and ventilation cranes and transports, electricity, etc. A picture of the last few months activity, mainly concentrated on the CMS experience, shows that synergies between project managers, personnel involved and group structures can strongly improve the service level in the specific divisional domains. A closer collaboration also seemed to facilitate the development of further opportunities tied to the competence available in the groups and of great interest to the experiments, like the participation of the design of the cooling system of several sub-detectors for the compact muon solenoid, as TK, EE, EB, SE, etc. The exponential increase of the demand confirms the divisional support as a real CERN need in this area, but also pushes ST to understand this dynamic environment and follow the evolution by adapting its structures. |
| LEP Tunnel Movements at Point 1 caused by LHC Civil Engineering |
| Abstract The excavation of underground openings causes the surrounding ground to move towards the newly created opening. The magnitude of the movement is dependant of various factors, such as the shape and the size of the excavation, the geotechnical ground conditions, the in-situ ground stress, the distance from the excavation, etc. The excavation technique and the rock support measures are to be adapted to the prevailing ground conditions to limit the displacements to an acceptable level. From the output of the numerical analyses for the design of the underground structures, data can be obtained to determine the predicted movements. For the particular case of the LHC excavations at Point 1 in close proximity to the existing LEP tunnel, a facility had to be designed and installed in the LEP tunnel to allow adjustments of the machine alignment to compensate for the tunnel movements. The design was based on the predicted displacements, and the adequacy of the facility has been validated during excavation. |
| Ponts roulants du LHC– Lot 3 |
| Abstract Cette présentation traitera du lot 3 des ponts roulants "lourds" du LHC, qui est constitué de sept appareils (plus un en option). Ils doivent équiper les zones d’expériences ATLAS, ALICE et la tête de puits du PMI2. La mise en place de ces ponts roulants est prévue pour les années 2002 et 2003. Cinq ponts sont destinés à l’expérience ATLAS, un portique pour l’expérience ALICE et le dernier pont pour la tête de puits du PMI 2 avec un pont en option ne devant servir que dans le hall de montage. La capacité de ces ponts s’étend sur une gamme de 16t à 2x140t et des hauteurs de levage de 6,5 m à 102 m. Les points forts de ces ponts seront la descente des bobines pour l’expérience ATLAS (deux ponts – trois chariots synchronisés) et la descente de 1200 cryodipoles et tous les aimants du LHC dans PMI2. |
| Study of the Ventilation at ATLAS Cavern UX15. Air Velocity and Temperature around the Muon Chambers |
| Abstract The CV group at the ST division is involved in an airflow simulation inside UX15 cavern to predict the air temperature and velocity profiles around the ATLAS Muon Chambers under the ventilation design conditions. In this paper, the simulation models that helped to understand the Muon Spectrometer thermal environment and the efficiency of the ventilation system in the ATLAS cavern will be shown. The case studies, results and conclusions will also be presented. |
| Introduction of a Target Cost Mechanism in one of the LHC Civil Engineering Contracts |
| Abstract Since February 1997 when the four main engineering contracts were issued to prospective bidders there have been many changes to the CERN requirements associated with civil engineering. The contract associated with the LHC machine (T054) has been the one most disrupted by these changes, many of which have come about as a result of the later than anticipated delivery of the Déclaration d’Utilité Pubique (DUP) from the French Government. This has led to all contractual dates being changed and significant acceleration of the works being instructed. This paper discusses a mechanism that has been introduced into the contract that enables all parties to work together in order to minimise the cost of these changes. The mechanism, which is based on a Target Cost, enables the contractor to obtain financial benefit from reducing the overall cost to CERN. |
Back to 4th ST
Workshop Home page
For comments
and changes send e-mail to ST2001 Workshop
Organisation Committee
Copyright CERN , modified 30/01/2001