Challenges of change
- Analytical Sciences Laboratory, Dow North America, Midland, MI (United States)
The Dow TRIGA Mark I nuclear reactor achieved first criticality on July 6, 1967. Since then it has been modified and improved to take advantage of instrumental progress and to avoid obsolescence. The reactor has been primarily used as a source of neutrons for neutron activation analysis (NAA) for the nuclear chemistry group within the Analytical Sciences Laboratory, which serves the Dow manufacturing and research facilities world-wide. This reactor, initially licensed to operate at 100 kilowatts, was previously owned, and came equipped with a vacuum-tube based control system bearing the serial number 1. In 1971 and 1973 new transistor-based equipment, a wide-range linear channel and a wide-range log channel, respectively, was installed, a considerable improvement. Fifteen years later a microprocessor-based instrumentation and control system was introduced by General Atomics (GA) to take advantage of instrumentation improvements and to provide replacements for equipment which could no longer be maintained. This system was installed at Dow in late 1990. The license was improved: at the time of the 1986 license renewal effort changes were made which allowed the reactor to be operated at power levels of up to 300 kilowatts in order to improve analytical sensitivity. That license, issued in 1989, is for a twenty-year span, which takes the facility well into the next century. Another license amendment in 1990 allowed the installation of the digital safety channel used in the new GA system. The new microprocessor-based system brought new ways of operating the new problems. Maintenance items now include network components and hard disks, among others, and different modes of operation are required. There have been a great number of computer-related unintentional shutdowns; our experience with this shows slow improvement. Significant improvements have been made in the instrumentation used for the NAA program. The original equipment was based on NaI(Tl) detectors (with one 5% Ge(Li) detector), sample changers, and dedicated multichannel pulse-height analyzers. The present instrumentation is based on an Ethernet-connected Micro Vax computer which controls two multi-channel analyzer systems, a robot sample server for two shielded systems each using two HPGe detectors, and an automated pneumatic sample transport system, with its own detector, for short half-life materials. The computer features automated data acquisition and reduction and can be accessed from desktop computers in the laboratory and from home computers. The very first operation of the reactor at 100 kilowatts in 1967 resulted in release of radioactive materials from a leaking fuel element, which was then identified and replaced. Very recently we have some experience of rare and sporadic episodes of extremely low-level releases of radioactive materials, which may be related to the concept of 'tramp uranium'. Investigation continues. (author)
- Research Organization:
- General Atomics, San Diego, CA (United States)
- OSTI ID:
- 21141160
- Report Number(s):
- INIS-US-09N0001; TRN: US09N0006020797
- Resource Relation:
- Conference: 14. U.S. TRIGA users conference, San Diego, CA (United States), 5-8 Apr 1994; Other Information: Country of input: International Atomic Energy Agency (IAEA); Related Information: In: 14. U.S. TRIGA users conference. Final program and summary of papers, 50 pages.
- Country of Publication:
- United States
- Language:
- English
Similar Records
Upgrade of the Dow TRIGA research reactor
U.S. Industrial and Commercial Motor System Market Assessment Report Volume 1: Characteristics of the Installed Base
Related Subjects
CONTROL SYSTEMS
DEC COMPUTERS
HIGH-PURITY GE DETECTORS
LI-DRIFTED GE DETECTORS
LICENSES
MAGNETIC DISKS
MICROPROCESSORS
MULTI-CHANNEL ANALYZERS
NAI DETECTORS
NEUTRON ACTIVATION ANALYSIS
NEUTRONS
NUCLEAR CHEMISTRY
RADIOACTIVE MATERIALS
ROBOTS
SAMPLE CHANGERS
TRIGA TYPE REACTORS
URANIUM