Design and operation of the ACRR instrumentation control and plant protect systems

Conference · Tue Jul 01 04:00:00 EDT 1980

OSTI ID:21149381

Boldt, K R; Sullivan, W H; Thome, F V; Morris, F M ^[1]; Hyde, W ^[2]

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1. Sandia National Laboratories, Albuquerque, NM 87185 (United States)
2. General Atomic Co., San Diego, CA (United States)

The Annular Core Research Reactor (ACRR) Control System was designed by Sandia National Laboratories and built by General Atomic Company. The ACRR Control System replaced the ACPR control console and includes many features which improve safety, control, and flexibility in the operation of the reactor. During the first two years of operation, the ACRR Control System has performed in an excellent manner satisfying all of its original objectives. The safety related instrumentation for the ACRR is contained in the Plant Protect System (PPS), which includes two instrumentation drawers and the magnet power supply. The PPS satisfies the intent of the IEEE-279 standard, in as much as it contains diverse, redundant, and physically and electrically-isolated protective action channels. In the pulse modes of operation, each PPS instrumentation drawer has scram capability on fuel temperature, peak power (nv), and energy (nvt). ACRR Technical Specification LSSS values for these parameters are 1400 deg. C, 60,000 MW, and 500 MJ, respectively. In the steady-state modes of operation, the PPS has scram capability on fuel temperature and percent power. The LSSS values for these safety channels are, respectively, 1400 deg. C and 115% of nominal maximum steady-state power of 2.0 MW. Manual scram and the low detector bias voltage scram are provided in all modes of operation. The PPS is not used for control purposes, but is solely intended to provide protective action. The control system consists of all components used to control power and reactivity. The components of the control system are rod drives and position indicators, two wide-range log/linear power channels, fuel temperature instrumentations, a shutdown drawer, an operational interlock drawer, and the ACRR timer. All regulating rods (2 safety, 6 control and 3 transient rods) are mechanically driven by stepping-motor drives which along with digital position indicators are capable of 0.25 mm resolution. The wide-range log/ linear percent power channels provide shutdown capability for each linear-power range and for reactor period. A shutdown interrupts power to the magnet power supply. All shutdown logic, including spare shutdowns for experiments, are contained in a single instrumentation drawer. Operational interlocks, which assist the operator in performing operations in a proper sequence, are also contained in a single drawer. The ACRR timer is a multifunctional timer which fires rods in pulse modes and drops rods in all modes of operation. The remainder of the ACRR instrumentation is for diagnostic purposes. This includes most of the pulse diagnostic channels such as peak power, pulse energy yield, reactor periods and maximum fuel temperature. These channels contain digital readouts and peak hold circuits for data retention after the pulse. Six thermocouples in instrumented fuel elements, 3 fission chambers and 22 self-powered detectors provide the majority of signals for all parts of the ACRR Control System. (author)

• Research Organization: General Atomic Co., San Diego, CA (United States)
• OSTI ID: 21149381
• Report Number(s): INIS-US--09N0119; TOC--12
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
ACPR REACTOR
CONTROL
CONTROL SYSTEMS
DESIGN
DISPLACEMENT GAGES
NUCLEAR FUELS
OPERATION
PEAK LOAD
REACTOR PERIOD
REACTOR SAFETY
REGULATING RODS
SCRAM
SELF-POWERED DETECTORS
STEADY-STATE CONDITIONS
TRIGA TYPE REACTORS