B513 Planning Meeting, 27th August 2002

Present:           Nigel Baddams, Tony Cass, Anne Funken, Jose Miranda, Dave Underhill

1.             Previous Minutes

  1. Approved with minor corrections.

2.             Substation Planning

  1. Gutor have now provided sufficient technical information to establish the cooling needs for a system based around Gutor UPS units rather than MGE units. Overall, the cooling needs are very similar—i.e. about 200kW. One minor draw back of the Gutor solution is that the batteries are in closed cabinets with cable access from the bottom. A false floor is thus required and this must be specially adapted to the weight of the batteries.
  2. Anne has had a meeting with ST/CV to discuss the power requirements of the hvac systems. It is now confirmed that 2MVA is insufficient to cover the peak load (in summer). Consequently, two 2MVA transformers are required. Maintenance will be scheduled during the winter when the air conditioning load is lower and only one 2MVA transformer is required. In addition to the extra transformer, additional switchgear will be required, and thus extra space in the bunker.
  3. Nigel presented pictures and plans to show that the clearance in the bunker can be at most 2.95m in the area under the loading door if access is to preserved as now (with lorries able to reverse to the door and lower a tailgate to the false floor level).
  4. An alternative solution would be to extend a loading dock out into the car park at the level of the false floor. The following points were noted for this solution.
    1. The door would need to be modified as this opens outward below the level of the false floor.
    2. The slope of the car park is such that direct access from lorries would not be possible. This is not seen as a problem as a forklift truck could be used.
    3. By itself, the loading dock would look intrusive, but the visual impact is much less once the transformers are taken into account—these would rise above the level of the loading dock.
    4. The most cost effective solution to create the loading dock would be to increase the clearance in the bunker in this section, to approximately 4m. This avoids the need for a large volume (~40m3) of concrete.
    5. There is no requirement for the walls to support the dock to go right down to the floor of the bunker—i.e. this solution does not impose a room of ~4m ´ ~10m in the middle of the bunker.
  5. An extensive discussion of equipment layout in the bunker followed. It became clear that the final layout cannot be prepared until the air conditioning arrangements for the 2MW physics UPS are determined. Physically, both the MGE and the Gutor solutions can be adapted to reuse existing space, but any split must be between logical UPS modules. For example, the MGE solution can be split 8+4 but not 6+6. Although 8 modules will fit in the existing UPS room, this cannot be used if only 6 modules can be cooled in this area.
  6. It was agreed that the air conditioning arrangements for the 2MW UPS must be decided urgently. Due account should be taken of the different clearances available (3.5m in the currnet rooms, 3m above a 1m false floor in the bunker with the possibility of up to 4m in a limited area). As the layout of UPS units can be fixed in advance, solutions involving local heat exchanges with preinstalled chilled water piping should be considered in addition to air cooling.

3.             Supporting an active load of 4MW

  1. Tony asked if and how the layout for the 2.5MW solution would differ if it was known that this would need to upgraded later to support a 4MW load.
  2. Anne believed that the 4MW solution might need to be very different for two reasons.
    1. The power needs for air conditioning and other services that must be maintained during a power cut may exceed 1.2MVA—the maximum load that can be supported by the sitewide diesels. If this is the case, then a dedicated local backup solution is required.
    2. The current plan is to connect the computer centre substation to the Isolde 18kV loop. This is limited to a maximum of 15MVA and may not be able to provide enough power to support the 4MW solution as 10MVA would be required to support all loads.
  3. Point a) again emphasised the need to understand the needs of the air conditioning solution.

4.             AOB

  1. Next meetings:
    1. 14:00 on Tuesday 10th September to review air conditioning arrangements.
    2. 14:00 on Monday 23rd September to review the bunker layout in order that Nigel can prepare the final plans.