Criticality evacuation detectors that locate the accident site

Journal Article · Tue Dec 31 04:00:00 EST 1996 · Transactions of the American Nuclear Society

OSTI ID:426412

Mihalczo, J T; Hutchinson, D P; Williams, J A; Thacker, L H ^[1]

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1. Oak Ridge National Laboratory, TN (United States)

Currently, criticality evacuation alarms are dispersed in nuclear processing facilities to alarm when a criticality accident has occurred. They are spaced to provide adequate coverage of a nuclear process area with a minimum number of detectors. Several alarms can trip simultaneously from the same criticality excursion. For example, prompt critical excursion experiments with the Health Physics Research Reactor in the Critical Experiments Facility (CEF) of the Oak Ridge Y-12 plant in 1961 tripped several criticality evacuation alarms in the main part of the Y-12 plant, which was separated from the CEF by a considerable distance and an {approximately}200-ft hill. Current alarm systems provide little information on the specific location of a criticality accident within a building. As a result, not knowing the exact location of a criticality excursion can lead to evacuation paths that do not minimize radiation exposure. The system proposed here employs a scintillation-based detector array or, alternately, a pin silicon diode array coupled with analysis electronics designed to not only produce an evacuation alarm but to determine the exact site of the criticality event so that optimum (lowest dose) evacuation paths can be determined instantaneously and automatically and can be quickly displayed for personnel evacuation. This system would also store the dose and time data comparison during and after the accident so that the information can be used for postaccident analysis. The system described here utilizes a large number of inexpensive detectors dispersed on a regular grid throughout a processing facility.

• OSTI ID: 426412
• Report Number(s): CONF-961103--
• Journal Information: Transactions of the American Nuclear Society, Journal Name: Transactions of the American Nuclear Society Vol. 75; ISSN TANSAO; ISSN 0003-018X
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
44 INSTRUMENTATION
INCLUDING NUCLEAR AND PARTICLE DETECTORS
CRITICALITY
DESIGN
RADIATION DETECTORS
SI SEMICONDUCTOR DETECTORS
SOLID SCINTILLATION DETECTORS