Williams, N W

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 122 FIRST YEAR EXPERIENCE WITH THE RHIC PERSONAL ACCESS SAFETY SYSTEM (PASS) N. W. Williams Brookhaven National Lab, Upton, NY, USA Abstract Review Operations first year experience with the RHIC Particle AcceleratorSafety System (PASS). This includes the accelerator access controls,radiation monitoring and the oxygen deficiency hazard(ODH) monitoringsystems. 1. INTRODUCTION A single RHIC Personnel Safety System was installed to protect the Collider personnel from RadiationHazards, Oxygen Deficiency Hazards (ODH), and Electrical Hazards and assure full compliance withregulatory requirements. In the past, ensuring personnel safety at accelerators meant an Access ControlSystem designed to protect personnel from radiation hazards only. Integrating all personnel safetysystems in RHIC is expected to result in a superior level of personnel safety and equipment protection,while providing greater operational efficiency. It is also intended that the Personnel Safety System havea closer interface with the fire protection elements installed as part of the conventional constructionthan has been the case in other accelerator construction. 2. DESCRIPTION Required safety systems for Oxygen Deficiency Hazards (ODH), Electrical Hazards and RadiationHazards are integrated into a single system. The Personnel Safety System will employ fourteen smallProgrammable Logic Controllers (PLC) interconnected as two sets of seven peers, channels ‘A’ and ‘B’in Fig. 12-1, rather than a few larger units hierarchically connected to multiple remote I/O chassis. Thisis done to achieve a higher level of redundancy for the most complex part of the system, than thatprovided by the dual level designs. 2.1 Control Devices Commercially available Programmable Controllers are configured to attain the level of redundancynecessary to achieve compliance with DOE 5480.25. A network of PLC units compensates for thecomplex set of failure mechanisms exhibited by individual processors compared to designs based uponrelays, much as an OP-Amp compensates for component variability with gain and feedback or a bridgeis supported by its interconnecting I-beams. In order to reduce the potential for Common Cause failure events, the core PLC system will becomprised of two different brands or models of PLCs (Allen Bradley PLC 5 and SLC 5/03,4 processors) such that basic hardware and software elements will be of different origin; each PLChas its own independent UPS and line power feed. Complications introduced by physical buslimitations result in a rather complex interconnection pattern, however, a minimum of two independentchannels labeled ‘A’ and ‘B’ is always maintained. The ‘A’ and ‘B’ channels are in turn connected toone of two Command and Control processors which provide supervisory control and monitoringfunctions. These processors are in turn redundantly connected to a Personnel Safety System-generateddisplay located in C-AD Main Control System (MCR).  123 2.2 Crash, Gates and Sweep sub-system An emergency shutdown system labeled CRASH, which uses ‘pull cord’ type switches, is installedthroughout the collider enclosure. With minor exceptions, these are essentially continuous coverage onboth sides of the enclosure tunnel. Because of magnet locations, coverage in supported injection areasare installed on one side only. Each unit protects 65 m (200 ft) of tunnel. The CRASH switches are nothard wired into a lockout system, but are connected in a redundant manner to a PLC in the ‘A’ channeland to another PLC in the ‘B’ channel. When a CRASH is called for, the Personnel Safety Systemremoves power from selected critical power supplies or closes selected critical vacuum valves. Inaddition, the Beam Dump System will be activated. This dual approach is necessary because the BeamDump system, while engineered and constructed to high standards, is not considered part of thePersonnel Safety System.The Gate system is comprised of thirty five (35) Gate packages and nineteen (19) EmergencyEntrance and/or Exit Doors packages. Redundant interlock switches are mounted on each of thesedoors. Each entry and isolation gate has standardized electronics system for information, display andaccess purposes. This package includes TV monitoring capability in the Main Control Room (MCR). Inaddition, there is a card reader based entry logging system and information display at each gate. TheRadiation Monitoring system uses the ‘Chipmunk’ design used at the AGS and at FERMILAB.Interlock outputs will be connected to system PLC units.Each crash, gate and sweep switch is monitored using a constant (32 mA @ +/-10 Vdc) currentsource that determines their status. This scheme reduces the complex cable network that would havebeen required for a completely hardwired system.  2.3 Remote Hardware Interface The PLCs use remote scanners, plug-in I/O modules and Remote I/O blocks to communicate with thefield hardware. All critical devices utilize a combination of relay and R I/O hardware interface. 2.4 Radiation Monitoring The Radiation Monitoring system employs the ‘Chipmunk’ design used at the AGS and at FERMI.Interlock outputs are connected to the PLC units. Of the approximately eighteen (18) units installed,FirewallPLCMasterPLCA-divField PLCP19Field PLCP5Field PLCP9Field PLCP7MCRPanelMasterPLCB-DivPASS System Block DiagramGatesCrashDH485 DH+Sweep 124 twelve (12) units for experimental area monitoring and six (6) units for RHIC injection. Dose rate dataare read by VME based optically coupled SIS3803 scalars into the central control system. 2.5 Oxygen Deficiency Hazards (ODH) The ODH system is comprised of sensing and processing electronic hardware. The sensing electronicsare built around a commercially available oxygen fuel cell. The detected ODH level is sent to the PLCcontroller which decides if the fans and vents need to be activated. The fans and vents are notautomatically activated during stores. 2.6 Flammable Gas Detection Systems Both the STAR and PHENIX experiments have Flammable Gas Detection System (P10 gas). Thissystem uses industrial grade fixed-point infrared detectors with visual and audible alarms. Fans andvents are used to exhaust the halls. The fans and vents are not automatically activated during stores. 2.7 Fire Alarm Interface to PASS The RHIC tunnel fire alarm system is connected to the PASS. This allows the use of ODH fans andvents to exhaust the tunnel during a fire. As in the case of the ODH and Flammable Gas systems, firealarms will not automatically exhaust the enclosure during stores. 2.8 PASS MCR Interface The MCR interface to the access system consists of the Closed Circuit Television (CCTV) system andPanelviewer computer terminals. The CCTV is used to perform remote access into RHIC entry gates.This uses video multiplexers and fiber optics cables to route the signals to MCR. The video switching isdone using a SLC based system. Panelviewer terminals are used to send commands and get status information from the fieldpeers.  3. UPGRADE TO THE AGS RELAY BASED SYSTEM Due to the unique requirements of two experiments running at the AGS, various upgrades were done tothe beam areas of the AGS access system. 3.1 NASA E951 Iris Identification NASA experimenters required a method of identification that would require minimal use of hands sincethey typically carry specimens. Iris identification does not require the use of PIN numbers but allowsindividuals to stand at the CCD camera and be recognized by unique characteristics of the iris. IrisIdentification in conjunction with Trapped Key Technology controls who can enter primary gate.Simultaneous release and video ensured MCR still had entry control. No beam is delivered by MCRuntil all keys are returned and trapped.The local reader uses a secure network to log entries in MCR. An enrollment station located inMCR allows users to be checked for proper training. Once scanned the individual’s iris code isdownloaded via Ethernet to a processor at primary gate. 125 3.2 Proton Radiography E933 This experiment uses the Hand Reader technology for access at LANL and requested this setup due toprior familiarity. This was also a cost effective means to address experiment requirements. Theenrollment station located in MCR allowed users to be checked for proper training. Once scanned thehand code is downloaded via Ethernet to the access hand reader at PTR house. 3.3 Advantages of Biometric System: • Totally hands free. No contamination. • Tremendously accurate.• Not affected by eyeglasses or contacts.• No laser as required by retinal scan.• Identification happens in 2 seconds.• CCD Camera is auto focus.• No password or PIN to remember. 4. LESSONS LEARNED • Micro-switches in the electric strikes were upgraded to improve the stability of the gatecurrent loops. Gold-plated contacts provided better performance and reliability. In general,these switches are more compatible for the low current loops used in PASS. • The MCR Panelviewer interface was re-designed to be user-friendlier. The operations staffcontributed to the design.CCTVMonitorsPanelviewerControls 126 NASA ACCESS CONTROL SYSTEMPROTON RADIOGRAPHY 5. UPGRADES FOR FY2001 RUN • During shutdown each of the 14 RF stations at 1004 A will have independent reachbacksystem to PASS. This will give more flexibility and diagnostics to monitor the RF stations.• A network will be installed at all the RHIC entry and GI gates card readers to a central server.This will enhance our ability to keep the personnel access status up to date. The card readerswill query the server for training information of a requester to enter the ring.• Local key trees will be installed at the experiments to enhance the access into IR regions.• Hand recognition will be used to verify training and to log entries.IRIS READER 5 KEY KEY GATE ENTRY KEYWITH SIM. REL.IRIS PROCESSOR IRIS READERBYPASSHAND READER HAND READERBYPASS  127 6. CONCLUSION During the first year of RHIC running, the PASS system performed well. Some changes were requiredto improve the User Interface. The MCR operation staff contributed greatly to the changes that wereimplemented to improve the system user interface. 7. ACKNOWLEDGEMENTS I wish to thank Roy Heyder, Jonathan Reich and Tom Tallerico whom contributed to the content of thepaper. References [1]  Robert Frankel, SAFETY SYSTEMS (WBS 1.12), RHIC Design Manual, January 1994.

First Year Experience with the RHIC Personal Access Safety System (PASS)

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