EJP - load reduction in France

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This is a special tariff available to all consumers - domestic to industrial designed to persuade customers to cut usage at 30 minutes notice. Essentially you pay 4 times the normal if you continue to use power during an EJP period, but get it considerably cheaper the rest of the time.

This encourages people to either switch off there washing machine or factory, or switch to diesel power.

As a result there is about 3000 x 1.6 MW diesels - in private hands, and these are all activated by the private owners to avoid the EJP tariff. I know this because i have been to France, and talked to the Caterpillar dealer about his - when I used to work for CAT UK. Amazingly no one else seems to know about it.

That is about 5 GW roughly the output of 2 typical coal fired power stations.


This page is extracted from the official CERN newsletters, shows that even CERN obeys the economic imperatives of the French EJP tariff, designed to force customers to use less power during high demand periods / unavailability of nuclear reactors.


    • In previous years CERN was able to limit its electricity consumption during the winter months sufficiently to be supplied from the Swiss grid. In order to make enough power available for the LHC machine and experiments at the lowest possible cost during the coming winter 2005 / 2006 CERN is supplied from the French grid by EDF (Electricité de France). As a consequence, when the grids are at peak demand during the tariff period 'Effacement Jour de Pointe' (EJP) in France, the energy price is at least four times as high as for the usual winter period.

From 1st November until 31st March these increased prices are applicable during twenty-two 18-hour periods, each beginning at 7 a.m. and ending at 1 a.m. the following day. Notice will be given by EDF to the Technical Infrastructure Control Room (TI) at 5 p.m. the previous day. The notice period may be reduced to two hours for days following weekends and public holidays, or omitted entirely for technical reasons.

During these days of EJP CERN has a strong financial interest to reduce its power consumption as much as possible whilst minimizing disruptions for LHC machine and experiment commissioning, accelerator and experiment tests and start-up.

In order to inform staff and users EJP days will be announced via the NICE Alerter and also on the luminous panels at the entrances of the Meyrin and Prévessin sites.**


Reduce Consumption**

    • Information** **will also be placed on the public PS, SPS and TI video pages, as well as in several CERN NEWS groups.

In the interests of all, staff should refrain from carrying out tests or work requiring additional power during these periods.

For more details please contact:

TI 72201 or [Tcr@cern.ch]

//Mario Batz TS/CV - Energy Management Panel//**

Extracted from: [1]

Issue No.46/2005

Mon 14th November 2005


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Members of the various Groups who participated in the commissioning of the power converters for one section of the LHC on 12 and 13 October.

The LHC is gradually taking shape. While the major operation of lowering the magnets into the tunnel continues, many of the machine's other components are gradually being installed and commissioned. On 13 October, the power supply to one sector of the accelerator was successfully tested over a period of 24 hours. This was the first time that all the power converters for the supply of electricity to one eighth of the machine had been operated together in situ.

Once installed the accelerator will have a power rating of around 200 megawatts (MW), which is equivalent to that of LEP. By way of comparison, the peak consumption for the Canton of Geneva is 400 MW. However, what makes LHC different is its use of superconducting technology. As a result of this, the LHC magnets will not lose energy by heating up when strong currents pass through them. However, in order to produce the magnetic fields of up to 9 tesla that they will need to control the trajectories of the protons they will have to be supplied with high-intensity current.

Thus, although their power consumption is relatively low (with peak rates of 50 MW during the acceleration phase and 25 MW during standard operations for physics runs, compared to the 200 MW rating for the whole of the machine), the magnets' special characteristics have called for a design and installation procedure that is completely different to that of LEP.

'The need for very strong currents with moderate voltages required the power converters to be placed as close to the machine as possible and new topologies had to be developed to reduce their size and increase their performance', explains Frédérick Bordry, Leader of the AB Department's Power Converter Group. Given that space underground is limited, the power converters selected are as compact as possible.

The LHC is equipped with more than 1600 power converters, which is more than 200 for each sector. They are mainly located in secondary tunnels, either side of the even points of the machine. However, a number are also located at the odd points, while smaller power converters are installed directly below the dipole magnets.

Their job is to convert the alternating mains current (18 kilovolts or 400 volts) into a high-intensity direct current, of up to 13000 amperes, that is as stable as possible.

'We are able to achieve a precision of several millionths for the intensity of the current delivered to the magnets', explains Frédérick Bordry. Large numbers of sensors and safety systems will be used to monitor that the machine is operating properly, triggering energy dumping if necessary. If any quenches occur on a magnet, enormous resistors will absorb the energy. The energy stored in the LHC's 1232 dipoles will be in excess of 10 Gigajoules, which is equivalent to that of an Airbus A380 travelling at 700 km/h.

Obviously, these high-intensity currents induce a lot of heating in non-superconducting cables, since, in contrast to the accelerator, this part of the electrical circuits is resistant. A substantial water and ventilation cooling system provides the cooling for the power converters and the enormous electric cables. 'As part of this first commissioning phase, we are particularly interested in checking the proper functioning of the power converters' peripheral infrastructures', underlines Roberto Saban who is responsible for co-ordinating LHC commissioning.

In addition to the Power Converter Group (AB/PO), which is responsible for designing and operating the power converters, a number of Groups from the AB, AT and TS Departments have also participated in the operation. The Cooling and Ventilation Group (TS/CV) checked the performance levels of the ventilation and cooling installations. The Electrical Engineering Group (TS/EL) monitored the heating of the cables, the electricity consumption and any disruptions to the power supply. The Magnets and Electrical Systems Group (AT/MEL) monitored the thermal performance of the energy extraction system. The Controls Group (AB/CO) provided the computing infrastructures as well as the control software and monitored the operation together with the Operation Group (AB/OP).

After this first period of operation at full power, the next stage will be the commissioning of the power converters next year, this time after they have been connected to the magnets. At that stage, the operation of other key elements, such as the electrical distribution box which provides the interface between the power-supply system and the accelerator, will be tested. In transferring the power to the magnets, the box has to ensure the transition from room temperature to that of the machine at close to absolute zero (around -270°C).

na-2005-120_0510015_06-web.jpg "

Checking the operating parameters for the power converters during their commissioning for one sector of the accelerator.

Article 2

na-2005-121_2601-web.jpg " European Commissioner Viviane Reding in front of one of the computers showing how the Grid works and, from left to right, Robert Aymar, CERN's Director-General, Wolfgang von Rüden, Head of the Information Technology Department, and Bob Jones, the newly appointed director of the EGEE project since 1st November.

Viviane Reding, European Commissioner for Information Society and Media, visited CERN on 28 October. Accompanied throughout by CERN's Director-General, Robert Aymar, and the Head of the Information Technology Department, Wolfgang von Rüden, the Commissioner visited the ATLAS cavern before going on to the Information Technology Department, where she was given a complete overview of CERN's activities in the strategic field of Grid computing.

Viviane Reding's visit coincided with the end of the EGEE (Enabling Grids for E-sciencE) conference, which took place in Pisa in Italy. Co-ordinated by CERN and funded by the European Commission, the EGEE project aims to set up a worldwide grid infrastructure for science. Eighteen months after it was launched, the project now encompasses 150 sites throughout the world and has passed the milestone of two million computing jobs, the equivalent of more than a thousand years of processing using a single PC.


    • A small team of engineers and technicians has recently finished the design of power supplies specially tailored to working in the demanding environment of the ATLAS Tile Calorimeter. Mass production of the units has now begun.**



The ATLAS Tile Calorimeter power supply development team (left to right): Ivan Hruska (holding brick), Francisca Calheiros, Bohuslav Palan, Jiri Palacky and Zdenek Kotek.

Power supplies are an important component of any particle detector. In ATLAS, as in the other experiments at the Large Hadron Collider, it is not easy to use standard, 'off the shelf' power supplies; they must survive radiation, tolerate magnetic fields, and satisfy limited space and water-cooling constraints.

For the ATLAS Tile Calorimeter, these constraints all proved challenging for the engineers designing the power supplies. The aim was to produce a universal power module in terms of input/output voltage, delivered power and cooling, for general use in a radiation environment. The result is a distributed low-voltage power supply (LVPS) system designed to survive a total integrated radiation dose of 40 krads and magnetic fields higher than 0.2 tesla, and delivering over 100 kW of electric power to the calorimeter. The system consists of many components but the main units are 256 boxes - the LV BOX - deployed around the Tile Calorimeter close to its data acquisition electronics.

The LV BOX is based on a 'brick' - the key element of the LVPS system. The custom-made bricks are basically isolated switching DC-DC converters with a maximum output power of 150 W, which have been designed to be radiation and magnetic field tolerant. They also have a further advantage, as Ivan Hruska, the electronic design engineer who has led the project since 2001, explains: 'They are much lower in price than commercially available radiation-tolerant modules.' This cost saving has been possible only due to the massive use of carefully selected and radiation tested commercial off-the-shelf (COTS) components.

Following on from the design phase, the production phase consists of assembling about 2500 bricks and other components into 300 LV BOXes and performing the final tests. Custom-made testers enable automated checks of the functionality of the bricks and LV BOXes to be done before they are installed in the ATLAS cavern. The very first production LV BOXes have already been used in the Tile Calorimeter cosmic-ray test reported recently in the Bulletin (see Bulletin No. 30-31/2005).

The Tile Calorimeter LVPS system also contains converters generating the input voltage for the bricks in the LV BOXes. These converters were developed in collaboration with the TESLA company from the Czech Republic and the Institute of Physics of Prague. All the components of the system include control units driven by a CAN fieldbus network from the ATLAS counting room.

The design team would like to thank all the people who supported and helped with the project. The team for development consisted of Ivan Hruska, Francisca Calheiros and Bohuslav Palan, The team also benefited from temporary work of two technicians from Prague, Jiri Palacky and Zdenek Kotek, who helped with prototyping and cabling design.

For additional information see [5]

  1. Article 4

Recently, the Canton's Department for Installation, Equipment, and Housing launched a survey into the presence of asbestos in buildings built in Geneva before 1991.

    • Their initial findings have caused some concern to the public, with buildings and landmarks such as the TSR Tower, the Temple de la Madeleine, and the Cathedral of Saint-Pierre all found to contain asbestos. Several employees here also contacted the Bulletin to find out more about CERN's approach in dealing with asbestos.

In the 1960s, asbestos' use was widespread. Its low cost and attractive properties made it a popular choice for insulating buildings. It was used in buildings throughout the world, including many at CERN.

However, since the 1970s the use of asbestos has been gradually limited. In France, the first specific rules for the protection of workers came about in 1977. Since then, its use was limited more and more, under pressure from European directives. Finally, a European directive in 1999 widened the ban on asbestos. It covered almost all the applications of the material from all member-states and took effect from the 1st January 2005.

CERN has closely followed the evolution of all these regulations, ensuring its own rules are up-to-date and in line with French, Swiss and European Regulations (see Safety Instruction IS43, last updated in 2003). For example, in 1977 asbestos was removed from the Gargamelle Experiment. Following that, the AD Accelerator, the PS Water Network, and more recently the LEIR Machine and certain galleries around the PS, have also been treated.

Despite the removal of asbestos from many places at CERN, there remain materials containing asbestos in a certain number of buildings and some equipment. The recognised risk is that asbestos fibres could be liberated in non-negligible quantities, mainly due to the natural aging of the material or as a result of a disruptive action, which can take place during maintenance.

However, CERN has organised a comprehensive survey of asbestos in its buildings, identifying the type of material, its location and condition. This survey defines the decisions that must be taken, which include: leaving the material in place, subjecting it to a re-survey at periodic intervals, contracting a specialised firm to carry out air monitoring, or organising the removal of asbestos by a certified firm.

Furthermore CERN's Safety Commission and the TS Department collaborate closely in managing the risks associated with ‘everyday' work sites, such as maintenance activities and building; or specific work sites for the removal of asbestos. In continuing with a systematic approach, CERN is ensuring that all building work is preceded with an evaluation of the asbestos risk.

All of the measures outlined above are in conformity with the regulations in place in the Host States.

For more information please consult CERN's Safety Instruction on the subject, IS 43, or contact the Chemical, Gas and Industrial Hygiene Section of the Safety Commission: Jonathan Gulley (78526)/Olivier Prouteau (73583).**

  1. Article 5



    • The insertion operations for the CMS solenoid magnet are now nearing completion. After the outer shell of the vacuum tank and the solenoid itself, the teams inserted the inner wall of the tank and its heat shield into the huge red yoke on 2 November. These spectacular manoeuvres are now being followed up by the painstaking connection work. Once this phase of the work has been completed, leak and pressurisation tests will be carried out on the cooling circuit of the cold mass. The vacuum tank can then be welded shut. It will then be placed under vacuum before the coil is cooled and the power is turned on.**

The information contained in these pages is extracted from the Cern Document Server

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