31

CERN/ST-DI/SP (2000-032)

12 mars 2000

ST TECHNICAL COMMITTEE (STTC)

Compte rendu n° 31 de la réunion du 21/02/2000

Présents : J.L. Baldy, E. Cennini, P. Ciriani, C. Dangoisse, S. Deleval, F. Grillo, L. Henny, K. Foraz, J. Garcin, H. Laeger, M. Lemaitre, J. Miranda, R. Nunes, S. Poulsen, R. Principe, S. Prodon, J. Roche, A. Scaramelli, L. Scibile, M. Wilhelmsson / ST
D. Geugnon / PS

Invités : J. Lindroos / ST
M. Storr / HR

Excusés : M. Batz, I. Bejar Alonso, R. Bellone, D. Blanc, A. Calderone, R. Charavay, P. Chevret, J. Inigo-Golfin, C. Jacot, G. Kowalik, M. Nonis, R. Parker, J. Pedersen, B. Pirollet, E. Sanchez-Corral, W. Van Cauter, T. Watson / ST
P. Collier / SL

1. Approbation du compte rendu n° 30

Le compte rendu n° 30 est approuvé.

2. Matters arising from the last meeting

R.A.S.

3. Web lecture archive project (M. Storr)

M. Storr makes a short presentation on a new system aimed to capture talks and restituate them precisely in such a way that them could be easily modifiable. This system is called "Web lecture archive". It stocks on the Web talks, seminars, training and meetings for reviewing later.
This project has been launched in collaboration with the university of Michigan and brought to CERN by ATLAS collaboration. It is based on the principle that transparencies are not enough and that the speech of the speaker is also important. It offers both in the same time. Indeed last year summer student lectures have been translated into a CD-Rom instead of transparencies.
M. Storr introduces a technical student who is pursuing this project in HR division.
Such a system may be used for record of meetings. It produces small video, high quality audio and high quality transparencies that are changed among the speech in accordance with the speaker's discourse. All these documents can be stored and archived on the Web.
M. Storr shows then some examples of applications of this system with a lot of possibilities for search. It also works with not powerpoint transparencies. These examples can be found at the following address: http//webcast.cern.ch. Support can be obtained from following E-Mail address: giossue.vitaglione@cern.ch.
As an example M. Storr captures the today STTC meeting.

4. Opération TCR (F. Grillo) (see transparencies)

F. Grillo présente les événements majeurs qui se sont produits durant les quatre dernières semaines :

Déclenchement sur un transformateur d'alimentation des stations de pompage 222, 204 et 216 (26/01/00)

Ouverture de la boucle SPS sur les réseaux pulsés et stables de la zone nord (13/02/00)

Fuite d'eau déminéralisée dans la Zone Est du PS (15/02/00)

5. Point sur la situation pendant le shut-down des machines (D. Gueugnon)

Une réunion de coordination des travaux est prévue le 27 février. D. Gueugnon indique qu'aucun problème majeur de coordination n'est pour l'instant à signaler. Le planning général est toujours valable. Ainsi, le LPI ferme aujourd'hui pour un redémarrage la semaine prochaine. Quant au PSB et au PS, ils seront fermés durant la semaine 10. Des protons seront injectés dès le 13 mars dans le PSB et 3 jours plus tard dans le PS. D. Gueugnon signale que le PSB sera fermé de 13h00 à 7h30 à partir du 1er mars.
Pour la phase finale, un briefing est prévu le 9 mars à 14h00. Il est principalement destiné au personnel d'opération.

En ce qui concerne l'UPS, la division PS propose de maintenir le statut quo.

D. Gueugnon se félicite de la rapidité et de la qualité des travaux effectués par le groupe TFM suite à sa demande.

6. User requirement for LHC fire and gas leak detection (R. Nunes) (see transparencies)

6.1. Goals

ST/AA/AS will install in LHC:

fire detection,
flammable gas detection,
oxygen deficiency detection,
evacuation systems.

It has to cope with user requirements:

TIS for protection of people,
owners of buildings for protection of equipment.

6.2. Surface

6.2.1. New equipment

CERN sites are divided into safety zones with one single fire detection control panel and one single gas detection control panel each.
R. Nunes describes then point by point what is already known and requested. He points out that no information has still been transmitted by the users for points 2 and 3. Fire and gas detection still exist for these points and needs have to be reviewed.

P. Faugeras explained in the last TCC that surface buildings are under the responsibility of their owners who have to define if their equipment have to be protected. If fire and gas detection are necessary, groups have to pay for it. A. Scaramelli estimates that fire and gas detection have to be included in operational groups (CV, EL, etc.) LHC budget.

6.2.2. Old equipment

All the equipment that is no more needed will be removed. In order to reduce maintenance costs old equipment will be either replaced by new equipment or removed when useless. Efforts will be made on reduction of spurious alarms with the aim to improve global performance.
R. Nunes underlines that this process can't be implemented without input from users concerning their needs on fire and gas detection.

6.3. Underground

Experiments are divided into 3 zones:

experiment itself (inside the detector)
experimental cavern
service cavern

6.3.1. ATLAS experiment

A working group has been set up to analyse the needs of detection inside the detector. The main idea consists in implementing a tubing network that ends up outside where the air is anlysed. These requirements represent an important workload for ST/AA/AS section.

Service cavern will be equipped with:

smoke detection :

in the cavern,
protection of electronic racks: the system should provide a clear localisation and identification of the rack which is smoking,

gas detection.

6.3.2. CMS experiment

CMS will use the same principles than ATLAS but at a smaller scale. No request has been made for detection in pits and service caverns.

6.3.3. LHC machine

Concerning fire detection, a consensus has been found on specific areas. The need of detection in the tunnel is still in discussion between TIS and LHC divisions.
No decision has already be taken concerning gas detection. If it is necessary detectors should be installed every 100 m.

6.4. Contract

ST/AA/AS uses 2 supply contracts:

B1133/ST for fire detectors in surface,
one contract for gas detectors in surface and underground.

Special contracts will be used for experiment specific needs.

7. Etude de faisabilité sur la ventilation du tunnel PS (J. Lindroos)

This presentation aims to describe ST/CV proposal for a modification of PS regulation and hardware.

7.1. Reasons to change

J. Lindroos gives 3 reasons to renew the PS air-conditioning system:

The installation is now aged (more than 40 years old) and breakdowns appear on the pipes. The last analysis made on the pipes(done in the beginning of 80’s) pointed out spots of corrosion on surface of chilled water distribution circuits.
The future LHC implies the same technical level for all the accelerators. The air-conditioning should also meet to this standard.
A new air-conditioning system also implies energy savings.

These arguments still need to be justified more precisely.

7.2. Present situation

A few keyworks can describe the present situation:

The PS tunnel is now equipped with 8 ventilation stations.
The exhaust duct contains abestos, which implies safety measures if touched.
The tunnel is in overpressure. TIS measures made in 96 demonstrated a level of radiation 100 times less than allowed.
Humidification / deshumidification system has been reduced some years ago, no problems in the level of humidity has been noted since.
Smoke extraction is carried out by six exhaust fans. The system is started by a smoke detection system and three fans are operated simultaneously.

7.3. Future situation

The major novelty will consist on:

4 new supply air stations will be created,
2 redundancy stations will be modified from old units,
2 exhaust stations will be used to create under pressure in the tunnel and for radiation monitoring.

7.3.1. New supply air stations

The use of the fresh air will be minimised. As a consequence the fluid heating network will be reduced and the necessary heating will be provided by electrical coils. Very little heating is required during the machine run, the biggest need is during the shut-down.
Air distribution system will remain the same. A smoke extraction operation will be added to the two stations presently without the extractors.

J. Lindroos proposes to implement the variable speed units for 3 modes of operation:

machine run,
shut-down,
smoke extraction.

7.3.2. Exhaust station

Speed controlled units will be operated by differential pressure measurement.

7.3.3. Redundancy stations

Heating operation will be dismantled. These stations will be used as spare in case of need of more cooling power.

7.3.4. Comparison of air flows

Future air flow will represent 70 % of the present flow and the fresh air 25 % of the actual volume.

7.4. Main principles

The temperature of the tunnel should fluctuate between 20(supply at floor level) and 25 °C(exhaust in the ceiling).
Heat loads will be evacuated mainly by water and partially by air(estimated some 300kW).

A. Scaramelli points out that present PS cooling system still uses very few "air neuf". He suggests to use underpressure in the tunnel and extraction with absolute filters.

Some questions are still pending and need more discussions :

what does PS need for the next years ?
what is the use of the system ?
how to cope with the INB ?

7.5. Cost and planning

The cost of this modification of the PS air-conditioning system is arounds 5 MCHF, including the renewal of pipes and stations.
Works should begin during the next shut-down and finish at the end of the shut-down 2003.

8. Séquences d'installation dans les cavernes ATLAS et CMS (J. Roche)

J. Roche présente les résultats d'une pré-étude sur les séquences d'installation des gaines dans les cavernes ATLAS et CMS. Tous ces éléments sont intégrés dans l'appel d'offres en préparation.

8.1. ATLAS

Phase 1 : mise en attente des gaines en tête de puits.
Phase 2 : mise en place des gaines souples : deux pour l'air neuf et une pour les gaz d'échappement.
Phase 3 : installation de l'échafaudage pour les gaines verticales et mise en place de la structure métallique.
Phase 4 : mise en place du pont roulant avec une plateforme négative pour arrimer les gaines sous la poutre du pont roulant.
Phase 5 : installation des gaines de pulsion et d'extraction à partir du sol.
Phase 6 : mise en place des passerelles.
Phase 7 : descente des gaines verticales.
Phase 8 : mise en place du plénum avec la création d'une structure complète mettant en jeu deux ponts roulants.
Phase 9 : achever la liaison physique des gaines de ventilation entre le plénum et la tête de puits.
Phase 10 : retirer les gaines souples.

Il est important de noter que la plateforme négative pourra servir pour d'autres corps de métier (éclairage, détection feu, etc.).
Les problèmes de hauteur ne sont pas négligeables. Ainsi, la caverne a une hauteur de 24 m (soit 8 étages) et atteint même les 35 m au sommet de la voute (soit 10 étages).

8.2. CMS

Le scénario est plus simple :

Phase 1 : mise en attente des gaines en tête de puits.
Phase 2 : mise en place des gaines souples : deux pour l'air neuf et une pour les gaz d'échappement.
Phase 3 : installation de la structure métallique.
Phase 4 : mise en place du pont roulant.
Phase 5 : mise en place des gaines sous le corbeau du pont roulant puis fixation à partir d'un échafaudage.
Phase 6 : mise en place du plénum.
Phase 7 : achever la liaison physique des gaines de ventilation entre le plénum et la tête de puits.
Phase 8 : retirer les gaines souples.

J. Roche regrette qu'il n'y ait pas de cintres car ils auraient été utiles pour le montage.

8.3. Discussions

8.3.1. Ventilation provisoire

J. Roche n'envisage pas d'utiliser une ventilation provisoire, il compte s'appuyer directement sur la ventilation définitive tant pour l'air neuf que pour les gaz d'échappement. Les gaines seront ainsi installées de haut en bas à partir d'un portique en tête de puits. Il n'y aura donc pas de ventilation pendant la pose de ces gaines. Ceci ne constitue pas un problème majeur compte tenu du tirage naturel. De plus, le tunnel de la machine sera ouvert.
Un alimak sera disponible pour ATLAS.

8.3.2. Nacelle négative et plateforme à ciseaux

La nacelle négative et la plateforme à ciseaux devront être intégrées au pont roulant en tant qu'option afin de préserver la garantie du pont. Elle pourrait être amovible et remise en place ultérieurement pour toutes les interventions de maintenance sur le pont roulant adéquat. Par contre, pour tous les dépannages, il sera possible ensuite d'utiliser les passerelles.
R. Principe rappelle qu'une habilitation est nécessaire pour tout le personnel appelé à travailler sur ces passerelles.

8.3.3. Coordination des travaux

R. Nunes indique que les tuyauteries nécessaires à la détection incendie devront être posées en même temps que les gaines de ventilation.

9. Divers

9.1. Interactions between cranes and fire detection

R. Nunes points out that cranes have to respect their parking position in order to avoid fire detection alarms when passing in front of the detector.
H. Laeger suggests to install (intelligent) fire detection systems in large halls in such a way as to provide permanent protection independant of the crane positions (several technical solutions are possible).

In any case this point has to be clarified and the results could be presented at a next STTC.

Prochaine réunion le 20 mars à 15 h

Sylvie Prodon

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Copyright CERN , modified 02/05/2000

Présents	:	J.L. Baldy, E. Cennini, P. Ciriani, C. Dangoisse, S. Deleval, F. Grillo, L. Henny, K. Foraz, J. Garcin, H. Laeger, M. Lemaitre, J. Miranda, R. Nunes, S. Poulsen, R. Principe, S. Prodon, J. Roche, A. Scaramelli, L. Scibile, M. Wilhelmsson / ST D. Geugnon / PS
Invités	:	J. Lindroos / ST M. Storr / HR
Excusés	:	M. Batz, I. Bejar Alonso, R. Bellone, D. Blanc, A. Calderone, R. Charavay, P. Chevret, J. Inigo-Golfin, C. Jacot, G. Kowalik, M. Nonis, R. Parker, J. Pedersen, B. Pirollet, E. Sanchez-Corral, W. Van Cauter, T. Watson / ST P. Collier / SL