Fusion Engineering and Design 85 (2010) 505–508 Contents lists available at ScienceDirect Fusion Engineering and Design journal homepage: www.elsevier.com/locate/fusengdes Interlock system for the COMPASS tokamak M. Hron a,* , J. Sova b , J. ˇ Síba b , J. Kovᡠr b , J. Adámek a , R. Pánek a , J. Havlicek a,c , J. Písaˇ cka a , J. Mlynᡠr a , J. St ˝ ockel a a Institute of Plasma Physics AS CR, v.v.i., Association EURATOM/IPP.CR, Za Slovankou 3, 182 00 Praha 8, Czech Republic b Department of Control Engineering, Faculty of Electrical Engineering, Czech Technical University, Technická 2, 166 27 Praha 6, Czech Republic c Department of Surface and Plasma Science, Faculty of Mathematics and Physics, Charles University, V Holeˇ soviˇ ckách 2, 180 00 Praha 8, Czech Republic article info PACS: 52.55.Fa 28.52.Nh Keywords: Tokamak operation Interlock Personnel safety abstract The COMPASS tokamak has started its operation recently at the Institute of Plasma Physics AS CR in Prague, Czech Republic. An important issue of the operation is the interlock system, which secures the safety of the personnel. The personnel protection is based on a restricted access into the experimental hall during the tokamak operation. An experimental hall access system, based on Honeywell WIN-PAK TM 2005, allows to set the status of the experimental area and to control the movement of the personnel. A hardware interlock, based on a PLC MicroPEL M66, interprets the experimental hall status and controls the safety of the operation of key systems accordingly. The permit for operation is granted and the real status of the systems is reported by hard-wired potential-less contacts. The PLC provides a HW interface between Actuators (relays and switches) and it is connected on PESNET bus. Second site of personnel protection system is created on a PC where runs a .NET application on MS Windows XP. This PC is connected with PLC via PESNET bus (on RS485 layer) and it creates an operator interface. Details of the set-up are described in this contribution. © 2010 EURATOM. Published by Elsevier B.V. All rights reserved. 1. Introduction Running a tokamak is a complex process, which includes a series of integrated technical tasks as well as personnel issues [1]. Here, we focus particularly on the personnel safety on COMPASS [2] that has to fulfill the national regulations in two aspects: (1) protection against danger touch voltage, given by state standards and (2) pro- tection against radiation hazards, regulated by the State Office for Nuclear Safety. A standard solution for the high voltage protection is using a barrier; the radiation regulation requires definition of a monitored zone. Therefore, we have chosen a further described solution based on a restriction of the access into selected areas (experimental hall, diagnostic rooms, power supplies and high volt- age areas, and NBI heating systems areas) during operation of the tokamak or its subsystems which are considered as a source of potential hazards. The basic scheme of the COMPASS personnel safety system (interlock) is shown in Fig. 1. It connects three key elements: exper- imental area access system, Programmable Logic Controller (PLC) hard interlock, and PC operator interface. First, the experimental area access system (described in Section 2) controls the access into the tokamak hall and defines the access rights into the area. Next, * Corresponding author. Tel.: +420 266053947. E-mail address: hron@ipp.cas.cz (M. Hron). the PLC based hard interlock (see Section 3) runs continuously and controls the links from and to the access system and the other toka- mak subsystems. It allows the operation of systems and unlocks the CODAC experiment controller. Finally, the operator interface (see Section 4) informs the operator about the status of the systems and allows to request changes in the status of the state-machine. Fig. 2 shows the interconnection of the systems in the experimental and technological halls with the CODAC and control room operator interface. 2. Experimental area access system The personnel protection against radiation and high voltage haz- ards is based on a restricted access into the experimental hall during the tokamak operation or operation of potentially dangerous sys- tems like high voltage power supplies and laser systems. The tokamak hall access monitoring is based on an industrial access control system, using Honeywell WIN-PAK TM 2005 [3,4] as a user interface. This interface is installed on a PC (equipped with Windows XP) and allows management and monitoring of the whole access system, including access cards control, access rights setting, hardware elements configuration, alarm handling, etc. The system allows the operator to choose the level of the access rights into the experimental area. The in and out movement of per- sons is then monitored accordingly, depending on the status of the experimental area. The access control is performed using access 0920-3796/$ – see front matter © 2010 EURATOM. Published by Elsevier B.V. All rights reserved. doi:10.1016/j.fusengdes.2010.03.054