1. Dick Loveless 20 January 20101 Status of UXC Dick Loveless 20 January 2010

2. Dick Loveless 20 January 20102 Cooling problem The failing component is a bushing adaptor between the flow restrictor and the rubber hose on the return assembly. There are ~400 bushings of this type on YE1, YE2, YE3 (mostly on YE1) which could potentially fail. A large fraction are inaccessible (to valve off or repair) and, in case of failure, would require shutting down the disk Proposed Plan: Open CMS beginning 16 Dec Beginning 4 Jan replace all bushings Close CMS (14 Feb?)

3. Dick Loveless 20 January 20103 Repair Procedure 1)Cut hose close to barb fitting 2)Insert swivel fitting into the cut hose and push hose onto the barb 3)Remove bushing and inspect flow restrictor diaphragm 4)Reseat diaphragm if it is misplaced (~3- 5% misplaced) 5)Place Loctite (sealant/lubricant) on the first few threads of swivel fitting 6)Screw swivel fitting into the flow restrictor Measured time for a single fitting: 10 minutes

4. Dick Loveless 20 January 20104 Testing Procedure I Gas Argon Insert Argon gas at 12 bar and use Argon sniffer to detect Argon Detector is large and heavy – must locate in cherry picker Need experience in operating Hydrogen Use bottle of non-flammable H 2 -Nitrogen (5% H 2 ) Insert gas at 12 bar and use H 2 sniffer Portable detector – easy to use and good sensitivity

5. Dick Loveless 20 January 20105 Testing Procedure II Water Close off racks and miniracks (no high pressure on heat exchangers) Fill disk with water and purge air for 4-5 hours Pressurize at 12 bar Visually inspect all new fittings for leaks Watch for pressure decay over several hours (20-30 mbar per hour acceptable) Decrease pressure and open racks and miniracks Circulate water normally and look for leaks

6. Dick Loveless 20 January 20106 StatusStatus Repair All 396 fittings replaced -- finished Testing YE+3 -- Argon testing started YE+2 -- H 2 testing complete on IP side, Argon testing begun on non-IP side YE+1 -- All testing complete -- operational YE-1 -- All testing complete -- operational YE-2 -- H 2 testing complete on IP side, Argon testing complete on non-IP side, water testing begun YE-3 -- H2 testing complete, water testing ongoing