ALARA Committee of 14th May 2012 IMPACT ON FIRE PROTECTION AND SMOKE EXTRACTION OF PRESENT AND FUTURE PS VENTILATION SYSTEMS ALARA Committee of 14th May 2012 14th May 2012 F.Corsanego

CONTENTS Impact of a fire in a physics facility Efficacy of present and future smoke extraction configuration Other Fire risk reduction measures (last talk in agenda)

1-IMPACT of a fire in a physics facility F.Corsanego

Risk=Probability· Consequences The probability of a fire in PS is no more than that for a normal electric facility; The consequences would be very severe, as a fire there could become a crisis for the Organization Criticality of PS for CERN physics program (SPS offline-BA3 fire in 1997, CTF3 offline in 2010); Danger of causing chemical and maybe radiological pollution (in the infrastructure, nearby buildings, and environment); Complexity of cleanup and restore in a RP controlled area Mediatic erosion of image F.Corsanego

Damage due to fire Damage of fire to equipment is minimally due to heat; most of the damage is made by soot and vapors contained in the smoke. In polyethylene and rubber fires a large percentage of the burning mass (~20%) spreads as soot in the smoke F.Corsanego

Extensive smoke damage to most of the the facility CTF3 fire - 4 March 2010 Cost 2.4 MCHF 4 Months stoppage only less than half of useful beam time in 2010 Cost /m2 = ~5000CHF/m2 Extensive smoke damage to most of the the facility Small fire within one cabinet F.Corsanego

Risk reduction strategy It is important, here more than elsewhere, to minimize probability of a fire, control its evolution, mitigate its consequence. Keywords: Smoke Dynamic Confinement (Smoke Extraction) Materials (cables & IS41) Static confinement (Compartments) Early fire detection Preplanned fire-fight F.Corsanego

2-smoke extraction: efficacy of present and future configuration.

Role of smoke control (smoke extraction) Loss of control of the smoke happens much more often than loss of control of the fire Bad smoke management = damage F.Corsanego

Criteria of success for smoke extraction in PS machine tunnel Goal: to avoid smoke spreading inside and leaks to nearby buildings To prevent damage, most of the smoke (let’s say ~90%) should be extracted by the first two extraction points this would confine damage within 2 stations, located at~75 meters) Smoke Extraction Stations 90% F.Corsanego

Efficacy assessment Machine tunnel: long geometry, efficacy of smoke extraction at distance from fire is hard to quantify without modeling ; Comp. Fluid Dynamic has been used for: comparing new smoke extraction vs. present situation; assessing aspects like : smoke propagation velocity in the tunnel thermal impact on structures at distance from fire Pressure differentials. F.Corsanego

basing on real scale tests of some degree of uncertainty Modelization of fire Fire growth cannot be calculated, this is a choice imposed to the CFD model. This is the most delicate part of the whole assessment (and in a tunnel this is very complicated because of absence of clear limits). We have to decide the most likely values, basing on real scale tests and acceptance of some degree of uncertainty I I I I I I F.Corsanego

Electric cabinet fires- laboratory tests (Source: AREVA-IRSN PICSEL_A. European Reaserch Program on Electric Cabinet Fires in Nuclear Facilities ) 40 kg of combustibles F.Corsanego

Heat Release Rate curves found in AREVA-IRSN test campaign on racks 1000kW 50kW --- = HRR curve chosen to verify smoke extraction F.Corsanego

Other fire size references (from another source). Item Heat Release Rate A burning cigarette 5 W A typical light bulb 60 W A burning candle 80 W A human being at normal exertion 100 W A burning wastepaper basket 100 kW A burning Electrical Cabinet Filled with IEEE-383 Unqualified Cables (Vertical doors closed, vent grills only) 185 kW A burning Electrical Cabinet Filled with IEEE-383 Unqualified Cables (Vertical doors open) 1.0 MW A burning 1 m2 pool of gasoline 2.5 MW Burning wood pallets, stacked to a height of 3 m 7 MW Burning passenger car 5-10 MW Burning polystyrene jars, in 2 m2 cartons 4.9 m high 30–40 MW Lorry Heavy good vehicle 30-150MW Output from a typical reactor at an NPP 3,250–3,411 MW (Source: NUREG-United States Nuclear Regulatory commission-Series Reports- fire risk assessment in nuclear facilities-chapters 1-2) F.Corsanego

2) 1) CFD Models Two type of models have been produced: 1) full circumference ring, to visualize propagation 2) rectified portions of machine tunnel, to evaluate efficacy 2) 1) F.Corsanego

1) Full model Next slides (video) show results of full model of PS ring: Conditions: 1MW fire lasting for 1000 seconds (~16’) located anywhere in the ring (between section 5 and 6) Smoke extraction = 6x12000 m3/h switched on Normal ventilation shut down F.Corsanego

1MW fire –Existing configuration (smoke extr.=6x12000m3/h) The two CV stations closest to fire fire origin Olive color lines=Smoke extraction location PS side walls Timeline [s] F.Corsanego

Video1 full PS ring, 1MW smoke-old configuration Video2 full Ps ring, 1MW temperatures, old-configuration F.Corsanego

1MW fire –Existing configuration (smoke extr.=6x12000m3/h) 16’ After 15 minutes of a 1 MW fire, most of the ring (and of the radial tunnels –not shown here) are filled with smoke F.Corsanego

T in the range of 150°C, for a 1MW fire F.Corsanego

Conclusion Fast propagation of smoke in almost the whole ring Temperatures remain low F.Corsanego

SEE template for presentations 2) Comparison of the smoke extractions (new vs. old) (*) All things equal, only smoke extraction power is changed between runs 1MW fire Sm.Extr. (*) m3/h Side wall Sm.Extr. (*) m3/h ceiling 75 meters octant EDMS No 1082781 SEE template for presentations

Boundary conditions table Existing Proposed Fire size 1 MW Normal ventilation Shut down Extraction [m3/h] Active 2x12000 2x30000 Success criteria 90% extracted Tunnel length simulated 100m of machine tunnel, to include two nearby CV stations (circumference rectified) F.Corsanego

SEE template for presentations 1MW fire –Existing config. (smoke extr.=(6x12000m3/h) EDMS No 1082781 SEE template for presentations

SEE template for presentations Video3 –1MW-smoke –rectified-old 2 x 12000 Video4-1MW-pressure-rectified-old 2x12000 EDMS No 1082781 SEE template for presentations

Soot extracted by sm.ext. SEE template for presentations Efficacy of the existing system (12000m3/h x 6) for 1MW fire Soot produced by fire Soot extracted by sm.ext. 3E-03Kg/s 6.6E-03Kg/s Efficacy ~40% EDMS No 1082781 SEE template for presentations

SEE template for presentations Video5-new-smoke-2x30000 EDMS No 1082781 SEE template for presentations

SEE template for presentations 1MW fire –New configuration (smoke extr.=(6[8]x30000m3/h) Most of the smoke is extracted EDMS No 1082781 SEE template for presentations

Efficacy of the new system (30000m3/h x 6[8]) for 1MW fire Soot produced by fire Soot extracted by CV Very good: smoke extraction ratio around 90% F.Corsanego

Effect of width and position of extractor Ceiling of tunnel: 6.2E-3 kg/s ~200% increase of efficacy Wall side of CV cubicle 3.4E-3kg/s (Feasibility still under discussion) F.Corsanego

Efficacy on a larger fire (2.5MW-30000m3/h) Efficacy=1.3/1.6 ~=80% still relatively good Soot generated =1.6E-02 kg/s Soot extracted= 1.3E-02 kg/s F.Corsanego

Verification with a different approach New (2x30000m3/h=16.6m3/s) Eff=~100% Eff=40-50% DATE F.Corsanego

Conclusion Full support to increase of extraction rate 30000 m3/h Activation matrix draft to be validated F.Corsanego

Ventilation control matrix in case of fire INPUT Equipment Ventilation Smoke extraction Automatic detection of a fire stop (option still open) Manual command by FB from one external switchbox on safe location Start/ stop Individual command for each extractor F.Corsanego

Thank you! Questions? F.Corsanego