[en] A solution to the problem of monitoring the radiation levels in and around a nuclear facility is presented in this paper. This is a private case of a large scale general purpose data acqisition system with high reliability, availability and short maintenance time. The physical layout of the detectors in the plant, and the strict control demands dictated a distributed and hierarchical system. The system is comprised of three levels, each level contains modules. Level one contains the Control modules which collects data from groups of detectors and executes emergency local control tasks. In level two are the Group controllers which concentrate data from the Control modules, and enable local display and communication. The system computer is in level three, enabling the plant operator to receive information from the detectors and execute control tasks. The described system was built and is operating successfully for about two years. (author)

No abstract available

[en] Short communication

[en] A rugged, portable, collimated gamma radiation detector for field use was developed. It was required that the detector will withstand severe environmental conditions such as rain. humidity, shocks and vibrations. (authors)

[en] A complete system for tracking, mapping, and performing a composition analysis of a radioactive plume and contaminated area was developed at the NRCN. The system includes two major units : An airborne unit for monitoring and a ground station for analyzing. The airborne unit is mounted on a helicopter and includes file following. Four radiation sensor, two 2'' x 2'' Nal (Tl) sensors horizontally separated by lead shield for mapping and spectroscopy, and two Geiger Mueller (GM) tubes as part of the safety system. A multichannel analyzer card is used for spectroscopy. A navigation system, based on GPS and a barometric altitude meter, is used to locate the plume or ground data. The telemetry system, consisting of a transceiver and a modem, transfers all the data in real time to the ground station. An industrial PC (Field Works) runs a dedicated C++ Windows application to manage the acquired data. An independent microprocessor based backup system includes a recorder, display, and key pad. The ground station is based on an industrial PC, a telemetry system, a color printer and a modem to communicate with automatic meteorology stations in the relevant area. A special software controls the ground station. Measurement results are analyzed in the ground station to estimate plume parameters including motion, location, size, velocity, and perform risk assessment. (authors)

[en] The Nuclear Regulatory Commission's (NRC) guidance, NUREG-1407, on performing Individual Plant Examinations for External Events (IPEEE) allows a Seismic Margins Assessment (SMA) to address the IPEEE seismic issue regarding the survivability of plant equipment during a seismic event and the capability of the plant to safely shutdown following the seismic event. The NRC guidance further allows the use of the NRC SMA approach or the Electric Power Research (EPRI) approach to evaluate these issues. In addition, the NRC's Unresolved Safety Issue A-46 (USI A-46) can also be efficiently addressed with the EPRI SMA evaluation. These methodologies are useful in determining a minimum list of equipment required for safe shutdown (i.e., Safe Shutdown Equipment Lists). The resultant Safe Shutdown Equipment List, SSEL, is used to identify the electrically powered equipment required for safe shutdown for which a relay evaluation is required. The evaluation of relays associated with safe shutdown equipment is necessary since equipment can fail to operate properly due to mechanical failure or improper operation/actuation due to relay failure. SAIC has performed relay evaluations on five nuclear power plants. This paper is intended to summarize the practical insights and lessons learned from use of the EPRI SMA approach

[en] The Airborne Radiation Monitoring System monitors radioactive contamination in the air or on the ground. The contamination source can be a radioactive plume or an area contaminated with radionuclides. This system is composed of two major parts: Airborne Unit carried by a helicopter, and Ground Station carried by a truck. The Airborne software is intended to be the core of a computerized airborne station. The software is written in C++ under MS-Windows with object-oriented methodology. It has been designed to be user-friendly: function keys and other accelerators are used for vital operations, a help file and help subjects are available, the Human-Machine-Interface is plain and obvious. (authors)

[en] A system, based on a new concept of controlling and monitoring distributed radiation monitors, has been developed and approved at the NRCN. The system, named ^BAKNET Network^, consists of a series of communication adapters connected to a main PC via an RS-485 communication network (see Fig. 1). The network's maximal length is 1200 meters and it enables connection of up to 128 adapters. The BAKNET adapters are designed to interface output signals of different types of stationary radiation monitors to a main PC. The BAKNET adapters' interface type includes: digital, analog, RS-232, and mixed output signals. This allows versatile interfacing of different stationary radiation monitors to the main computer. The connection to the main computer is via an RS-485 network, utilizing an identical communication protocol. The PC software, written in C ++ under MS-Windows, consists of two main programs. The first is the data collection program and the second is the Human Machine Interface (HMI). (authors)

[en] A mobile environmental radiation monitoring station has been developed and established for the Israeli Ministry of Environment. The radiation monitoring station is ready for immediate placing in any required location, or can be operated from a vehicle. The station collects data Tom the detector and transfers it via cellular communication network to a Computerized Control Center for data storage, processing, and display . The mobile station is fully controlled from the. Routinely, the mobile station responses to the data request accumulated since the last communication session. In case of fault or alarm condition in the mobile station, a local claim is activated and immediately initiates communication with the via cellular communication network. (authors)

[en] Alpha contamination is a common phenomena in radiation research laboratories and other sites. Training staff to properly detect and control alpha contamination, present special problems. In order to train health physics personnel, while using alpha sources, both the trainers and the trainees are inevitably exposed to alpha contamination. This fact of course, comes in conflict with safety principles. In order to overcome these difficulties, a training detector was developed, built and successfully tested. (authors)