C. Lu, K.T. McDonald RPC Gas System Final Design Review April 11, 2008 Daya Bay RPC gas system fire safety issue Slides from Gas System FDR + a few more

C. Lu, K.T. McDonald RPC Gas System Final Design Review April 11, 2008

Daya Bay RPC gas system fire safety issue

Slides from Gas System FDR + a few more new slides.


How Much Gas Should Be Stored Underground?Tradeoff between frequency of transport/changeover of bottles vs. degree of

oxygen deficiency hazard and flammable gas hazard from leaks at bottles. A new quote indicates Isobutane in US only has two cylinder sizes: 116 LB @ $400.00; 17 LB @$145.50, unit price almost 2.5 times higher in small cylinder. Use 116 LB cylinder can cut down the gas cost from $52,067/year to $49,609/year.

In addition to bottles in use, a second set of bottles should be underground at all times.

In the following configuration 54 bottles underground (Red color IHEP’s cylinder specs, black color US cylinder specs).

Exp. Hall Gas Cylinder Days/90% of cylinder used

Near Hall

Ar 6 #300 cyl. @2400/1800psi 35/26

R134A 90 LB/100kg 24/58

Isobutane 17 LB/50kg 37/240

SF6 35 LB/4kg 243/61

Far hall

Ar 6 #300 cyl. @2400/1800psi 22/16.5

R134A 90 LB/100kg 15/37

Isobutane 17 LB/50kg 23/149

SF6 35 LB/4kg 150/38


How Much Gas Should Be Stored Underground? (cont’d)

We just learned from Dana’s Email about the quantity allowed in the gas room:

“Maximum Flammable gas is 750ft**3. Quantity can be doubled if sprinklers (4.1.3.1.4) and Doubled if in approved storage cabinets, gas cabinets or exhausted enclosures.”

50kg Isobutane cylinder is within this limit:

2 such cylinders are needed in each site 100kg

Equivalent volume of 100kg Isobutane = 100000g/58g*22.4l/1000l/0.0283 = 1365 ft3 < 2* 750 ft3.

Question:

Does the sprinkler itself can double the total allowed flammable gas volume?

Does any one of the “approved storage cabinets, gas cabinets OR exhausted enclosures” can double the total allowed flammable gas volume?


Daya Bay Gas Monitoring System — Logic diagram


Gas system status crate


Gas system status crate — Logic diagram


HAD Sensor

Various brands of HAD sensor can be used to detect % LEL(Low Explosive Limit) for many flammable gases, Isobutane is one of the detectable gases.

FYI, the working principle of HAD sensor:


HAD sensor (cont’d)One candidate of such HAD sensor is RAEGuard LEL.


Backup slides


Cost estimation of the safety crateGAS SYSTEM STATUS PANEL

Part Discription QTY PRICE ea DISTRIBUTOR DISTRIB # TOTAL PRICE SOURCE OF QUOTE Sub-total # of sets Total Grand total24V converter 1 $95.00 Newark 83F2437 $95.00 Lambda kwd15-1212 $11,716.39 3 $35,149.17 $57,994.65

conn 12pin male-female 1 $10.00 $10.00conn 4pin male-female 5 $10.00 $50.00conn 8pin male-female 3 $10.00 $30.00

Fuse 4 $5.00 $20.00krpa-11dn-24 1 $12.44 Newark 21F1087 $12.44 TYCO_Relay_KHAU_11DN

LIGHT 14 $2.00 $28.00Power Socket 1 $5.00 $5.00

HAD sensor (EX-5100) 4 $1,145.00 Enmet Corp. $4,580.00 Email quote from Enmet. Http://www.enmet.comSimpson H335 8 $265.00 $2,120.00 Email_quote_Simpson_meter

Photohelic 3000SGT 8 $418.00 Dwyer Instruments $3,344.00 http://www.dwyer-inst.com/htdocs/pressure/Series3000Price.cfmPitot tube (160-8) 8 $46.75 Dwyer Instruments $374.00 http://www.dwyer-inst.com/htdocs/airvelocity/Series160Price.cfm

Mounting accessories for Pitot tube 8 $48.50 Dwyer Instruments $388.00 http://www.dwyer-inst.com/htdocs/airvelocity/Series160Price.cfmHumidity sensors w/ Swagelok Tee 4 $100.00 Honeywell HIH-4000-003Newark SKU 15M0250 $400.00 http://www.newark.com/

Weather Pro Center, WS-2315 1 $259.95 La Crosse Technology $259.95 http://www.lacrossetechnology.com/2315oak/index.phpFront Panels 6u (19"x10.5") 1 $42.00 Newark 25B6425 $42.00 BUD PA-1106-BT $538.00 3 $1,614.00

Panel Silkscreening 1 $200.00 $200.00PCB board (size 150 sq"??) 1 $296 $296.00

Electric weight scale system 1 $5,150 Force Flow $5,150.00 http://www.forceflow.com $5,150.00 3 $15,450.00HAD sensor calibration equipment 1 $265.00 $265.00 Email quote from Enmet. $265.00 1 $265.00

Labor hours charge/hour Total costPCB designs 16 85.82 1373.12 $5,516.48 1 $5,516.48panel deigns 8 85.82 686.56EP Lab 16 87.32 1397.12Assembly 24 85.82 2059.68


Air ventilation sensor and controller

Pt is the total pressure, Ps is the static pressure. Notice the sensing holes for these two pressures. The manometer shown on the left can measure the pressure difference between Pt and Ps, this is Pv, the air velocity pressure.

Working principle of using Pitot tube to measure the air velocity.

Dwyer model Photohelic 3000SGT pressure transmitter/controller


Suggested air ventilation scheme

To keep the air sweeps every corner of the gas rooms, the air ventilation duct has to be arranged properly. Shown on the left is a sketch of the BaBar gas shack air ventilation system. It shows 4 sensors are installed at 4 critical location: (1) room air source; (2) room air return; (3) exhaust room air; (4) fresh intake air.


Our Present Budget Estimate

Project Management (W. Sands) $30k System/crate Design (W. Sands, S. Chidzik) $25k 3 mixing panels $75kControl boxes for the mixing panels $25kInput bubbler systems $20kOutput bubbler systems $80kWater admixture systems $5kGas cylinder changeover systems $25kConversion of 1st panel from QC to production use $10k

or 4rth mixing panel $15k additionalHazardous gas safety system $60kInstallation at Daya Bay $16kArchival drawing sets $10kTest, QC/QA $35kShipping $14kTotal $430k = $254k + $176k

or $445k = $254k + $191k (red NOT in present RLS) (blue in present RLS accounting)

Documents

C. Lu, K.T. McDonald RPC Gas System Final Design Review April 11, 2008 Daya Bay RPC gas system fire safety issue Slides from Gas System FDR + a few more