ST TECHNICAL COMMITTEE (STTC)

Compte rendu n° 46 de la réunion du 15/10/2001

1. Approbation du compte rendu précédent

Le compte rendu n° 45 est approuvé.

2. TCR Operation (M. Bätz - H. Nissen) (see transparencies)

• Event: 25 September 9:20 – 10:58
  M. Wilhelmsson and M. Batz shall follow-up on this event to prevent similar things to happen in the future.

• Event: 3 et October 14:01 – 16:50
  The automatic switch off of the station has been modified to reduce consequences for the experiment.

• Event: 10 October 19:20 – 20:00
  The detector in the tunnel has been defect and has been replaced by a new one.

• Event: 12 October 15:02 – 15:20
  J. Pedersen explains that the interlocks have to be revised. The work that caused that stop was related to the commissioning of the third compensator.

3. PS Operation (S. Baird)

• LINAC2: On 10/10/01, it was scheduled to change an RF tube at LINAC2. However, when the intervention started it was rapidly found that the crane, PR161, in building 363, was not working. The motor had been removed in February by the firm Delattre and not replaced. The RF tube could not be replaced without this crane.This was signalled to the ST and by the end of the week a temporary repair had been completed, so that the crane can be used, but only at the lowest speed. It is hoped that a permanent repair will be completed as soon as possible.

• The problems of the water infiltration into the nTOF zone (5/10/01) was covered in the TCR report. The major worry here was that the water could be radioactive, but it was not. There was good collaboration between TCR, Gematec, MCR operators, the CERN fire services, radio protection and safety people to find the problem and resolve it safely even over a weekend.

• The fire alarm fault in the PS tunnel was also covered in the TCR report.

• A PS magnet F61.BHZ01 has developed a water leak and it cannot be fixed or replaced (too radioactive and too long a stop for other beams). This equipment is not under ST responsibility, but the demineralised water loss is about 3 m3/day. At the moment the magnet is off and therefore not leaking, but the DIRAC experiment will lose 3 weeks of beam time, if it stays off. Therefore they have requested that the PS try to find a way of running at reduced current in spite of the leak. The lost water is not radio-active and J. Kuhnl-Kinel says we can stand the loss. However, I think it is very unlikely that we will be able to run at reduced current etc. If we want to try we will inform TCR and J. Kuhnl-Kinel etc.

4. SPS operation

Summary notes of the 27th meeting of the SL Operations Committee held on 11th October : http://cern.web.cern.ch/CERN/Divisions/SL/SLOC/archive/mins027.html

29/9: vacuum leak in cavity coupler adjacent to the one that leaked on 13/9, both probably due to cooling water problems. ST/CV will upgrade the system in the coming shutdown as a result, plus the HRF group will replace all 'old' style coupler windows with new ones.

9/10: Magnet vacuum leak in TT20. The replacement was complicated and lengthened by several logistical problems including the intrinsically difficult access to TT20, a broken down BA3 lift and problems with the electrical connection of the tractor (all extension leads being used in LEP dismantling).

5. Status report "Désenfumage SPS" (M. Nonis) 

Il est rappelé que ce travail consiste à modifier le fonctionnement des unités de traitement d'air du SPS pour pouvoir fonctionner à une vitesse unique, avec un débit de 55.000 m3/h, mais avec des consommations de puissance électrique compatibles avec le réseau secouru.
Les contacts avec l'entreprise qui devrait réaliser les travaux ont avancé et  une commande détaillée des travaux à réaliser pendant le shutdown prochain vient d'être préparée.
Le papier qui circule pour remarques et approbation aux personnes concernées des Divisions ST, TIS et SL est prêt à être mis dans sa forme finale avec l'ajout de quelques remarques mais tout le monde a donné son feu vert pour les travaux.
Les travaux sont prévus en novembre au BA4, décembre au BA6 et janvier au BA2, en considérant 3 semaines de chantier par point.

6. PS-Cooling systems (M. Wilhelmsson - J. Lindroos)

6.1 Renovation of the cooling stations hall Sud and hall Est

M. Wilhelmsson explained the main objectives for the project which can be summarized in :

• A renovation of the two stations, both the hydraulic part as well as electric boards and controls. This is done since the stations are in very bad conditions. In addition, the cooling power is now longer sufficient for the Est hall.
• A symmetric ayout of the new stations will allow that the two plants can, with the help of a by-pass connection on the secondary side, be redundant for one or the other.

The enclosed MS-project sheet, shows the schedule for the project as well as the cost (expense-) profile.

6.2 Replacement of chilled water pipelines in the PS tunnel

J. Lindroos explained the status of the project and the planning for the rest of the works with budget needs :

• Due to the asbestos problem the contract with Iniziative could not be completed last shut-down, the upcoming shut-down the work will continue with the same contractor and a specialized company for asbestos work
• Abt. 35% of the ring was done in 2001, abt. 30% is foreseen to be done 2002 and the rest 35% in 2003.

The budget needs for the project are :

• 2001    -                 (piping)         25 kCHF     (asbestos)
• 2002    50 kCHF    (piping)         60 kCHF     (asbestos)
• 2003    220 kCHF  (piping)         70 kCHF     (asbestos)

The total needed in addition to the present contract : 425 kCHF

7. LHC Ventilation Process Control Migration LHC (D. Blanc) (see transparencies)

The aim of the presentation is to explain the situation of the present control system of the LEP ventilation process, to propose, plan and estimate the technical solution for the migration of the control architecture. This is done considering the fact that some essential elements of the present control infrastructure could no longer be supported by 2003 and major components shall be removed from any CERN communication infrastructure.

The adaptation of the present ventilation systems as well as the integration of new equipment to fit the LHC ventilation requirements lead us to consider a global re-engineering of the existing control system including the modifications of the control architecture. This is done in order to adapt an old decade process control structure. This structure is composed of elements which are a mixed between industrial and home-made devices. These modifications are to be made in order to upgrade the present industrial control system and to provide a complete, efficient and well adapted control architecture to integrate the LHC ventilation equipment of the injection tunnel and to face with the next fifteen years of the LHC life cycle and avoid becoming obsolete.

The motivation for the upgrade of the present structure is the replacement of old technology elements that are no longer supported -or that will not be supported in a short term and the need to adapt the control system to follow further requirements described below :

• The existing control infrastructure, which is presently supported by the SL-CO Group is going to be reengineered during the oncoming two years (approximately up to end 2002). This is the purpose of the HELIX Project (SL Division). Consequently, components which compose the present control architecture for the LEP Ventilation process shall not be supported later than 2003.
• The Sinec L1 bus used in this control architecture, is not longer available and supported by Siemens.
• The LHC machine might introduce new operating modes for the ventilation of the tunnel. Different operating modes involve the reconfigurations of the existing LEP Ventilation air units infrastructure. Consequently, an upgrade of the control system is required.

A number of factors must be considered at the beginning of the project and will have a consequent influence on the work load and the financial evaluation in parellel :

• Lack of documents on PLCs air-units application software.
• ECAs is more than a basic gateway and contains some part of ventilation application programs.
• Siemens Siclimat-software is not a standard software.

The magnitude of the works can be summarize as following :

• Preliminary Ventilation Process Engineering ST/CV
• Functional Analysis ST/CV - ST/MO
• Works ST/CV - ST/MO (ST-C168 contract or call for tenders).

  Back to STTC Meetings Home page 

For comments and changes send e-mail to ST Secretary or Divisional Web masters
Copyright CERN , modified 12/11/2001