Calculated in-air leakage spectra and power levels for the ANSI standard minimum accident of concern

Journal Article · Sat Dec 31 04:00:00 EST 1994 · Transactions of the American Nuclear Society

OSTI ID:89148

Lee, B L; Dobelbower, M C; Tayloe, Jr, R W; D`Aquila, D M

The ANSI/ANS 8.3 standard defines the minimum accident of concern for criticality alarm systems (CAS) as the accident that can deliver a dose of 20 rads in 60 s at a point 2 m from the surface of the system in free air. A definition this broad presents the criticality specialist with a dilemma when attempting to define critical systems in terms of power level, composition, and geometry to use in analysis of placement and/or response of a CAS. In any process application, the number of combinations that may be obtained in terms of composition and geometry are essentially infinite. In a uranium enrichment diffusion cascade, where the working gas is uranium hexafluoride, it is typically assumed that the fissile material that may be involved in an accident will be uranyl fluoride in some unknown geometry with some degree of moderation. The purpose of the work described in this paper is to attempt to create a conservative model of a critical system that may be used in calculations to demonstrate CAS compliance with ANSI/ANS 8.3. This would involve attempting to determine the significance of any geometric dependence along with the significance of the degree of moderation of the system. An additional variable in this work is the choice of a response function to convert the calculated leakage spectra to terms of dose and subsequently a power level for the minimum accident of concern.

• OSTI ID: 89148
• Report Number(s): CONF-941102--
• Journal Information: Transactions of the American Nuclear Society, Journal Name: Transactions of the American Nuclear Society Vol. 71; ISSN TANSAO; ISSN 0003-018X
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
99 GENERAL AND MISCELLANEOUS
FUEL ASSEMBLIES
GODIVA REACTOR
JEZEBEL REACTOR
M CODES
NEUTRON LEAKAGE
SPECTRA
X CODES
ZERO POWER REACTORS