350MHz RF Waveguide Air Personnel Safety System Dave Bromberek March 3, 2008
2 Outline System Operation and Layout Failure Modes 3 Year Calibration
3 System Operation Pressurization of the 350MHz waveguide system in Bldg. 420 is used as THE means of providing rf radiation personnel protection in the event of a breach of the waveguide system (see also technical note “Measurements of RF Power Radiated From Open WR2300 Waveguide Flanges” – D.Horan 7/3/05). Blowers on the rf cavities provide cooling air to the input couplers and also slightly pressurize the waveguides to ≈ 3-4”H2O (≈ psi.). The pressure is monitored and interlocked by eight waveguide photohelic pressure gauges, one or more of which is capable of detecting a waveguide flange gap of.185”, in all available waveguide switching modes. A trip of any waveguide photohelic will shutdown all five 350MHz klystron stations. Orphan photohelics are installed at RF1 and RF3 to provide protection in these areas when the stations are switched off-line. Additional photohelics monitor cavity blower pressure (Not Interlocked).
4 System Layout Two blowers supply cooling air to the input coupler and slightly pressurize the waveguide. Each cavity’s blower manifold is monitored by a photohelic. Cavity blower pressure is alarm only Each sector’s waveguide is monitored by a photohelic. Waveguide air pressure is a PSS interlock and will trip all 5, 350MHz rf stations.
5 System Layout
6 There are two blowers on each rf cavity, one being redundant. The cavity photohelics are on a scale on 0” – 10”H2O and read 10” or better with both blowers at full speed. Blowers are fed from two 120VAC power circuits/sector. Each cavity blower pair is fed from a separate circuit.
7 System Layout Waveguide photohelics are on a scale of 0” – 5”H20 and normally read between 3” - 4.5”H2O. Pressure sampling port is located on a section of waveguide in Bldg. 420 (see drawing)
8 System Layout Photohelic gauges are individually fused. A 24VDC power supply feeds the setpoint contacts from the cavity gauges to Allen/Bradley Fuse 24VDC Power Supply
9 System Layout
10 Blower Control Screen From RF Panel – Select Sector Cavity Photohelic Setpoint Contacts Blower AC Power Circuits
11 RF6 Waveguide Air PSS Screen From RF Panel - Misc/Tools
12 OAGapps Data From x-term type OAGapps
13 OAGapps Data
14 OAGapps Data
15 OAGapps Data
16 OAGapps Data
17 Failure Modes Cavity Blower AlarmCheck locallyDead or dying blower 8” H2OCheck OAGapps SymptomsStepsProblem
18 Failure Modes Cavity Blower AlarmCheck locally2 dead blowers 0”H2OCheck RF6Hose disconnected Check OAGappsBad Gauge SymptomsStepsProblem
19 Failure Modes Cavity photohelic hoses CAN be disconnected and connected to an adjacent gauge to eliminate the photohelic as the culprit. NEVER disconnect the waveguide photohelic hose unless the rf stations are already down due to a WG Air PSS trip. If it is determined that a waveguide photohelic is the problem, or the system is tripped on waveguide air, a work request and CCWP must be submitted and approved. C1C2 C3C4WG
20 Failure Modes 4 Cavity Blowers in AlarmCheck 24VDC P.S.Power supply 10”H2O SymptomsStepsProblem
21 Failure Modes 4 Cavity Blowers in AlarmCheck OAGappsAC Power 0” or Low “H2OCheck AC Power breakers Waveguide Air Trip SymptomsStepsProblem
22 Failure Modes Waveguide Air TripCheck waveguide integrityAny of these 0” or Low ‘H2OCheck for hose disconnection Gauge SymptomsStepsProblem
23 3-Year Calibration & Testing See “Technical Note on the Testing of the 350MHz Waveguide Air Personnel Safety System” – D. Bromberek 10/21/05 Test and adjust setpoints –Requires the opening/closing of five waveguide flanges (one at each station), in twelve waveguide switching modes – 60 iterations –Data is recorded and setpoints chosen.185” uniform gap in a waveguide flange trips RF6 PSS System.185” gap is detected by at least one photohelic in every waveguide configuration Loss of one cavity blower does not trip the PSS Loss of two cavity blowers does trip the PSS (Not always possible) –Validation and sign-off of CCWP requires tripping each of the eight waveguide photohelics one at a time, and verifying that it trips ALL FIVE STATIONS.
24 3-Year Calibration & Testing.185” Spacers.185” spacers in use
25 3-Year Calibration & Testing Data RF3 – May 2005
26 3-Year Calibration & Testing Simplified Data From RF3 – May 2005
27 3-Year Calibration & Testing Calibration due spring shutdown ’08.