Impact of hafnium flux-reduction inserts on power range detectors

Conference · Tue Jan 01 04:00:00 EST 1991 · Transactions of the American Nuclear Society; (United States)

OSTI ID:5981848

Frank, F J; Pulver, E F ^[1]; Trikur, F W; Lee, D K ^[2]

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1. Westinghouse Electric Corp., Pittsburgh, PA (United States)
2. Commonwealth Edison Co., Chicago, IL (United States)

A major reactor flux reduction study was undertaken by Commonwealth Edison Company to identify appropriate means to lengthen the license period and design basis of Zion units 1 and 2 and to maintain the option to operate the plant 20 additional operating years. Since neutron embrittlement represents the most significant mechanism that could potentially limit the availability of the reactor vessel, neutron flux reduction measures through fuel management were examined. One option for reducing the neutron flux along the beltline region of the Zion unit 1 reactor vessel was through the use of hafnium absorber rods. These hafnium rods are placed in guide tubes of assemblies at the periphery of the active core adjacent to the NIS power range detectors. It is sufficient to limit the hafnium absorber material to a 3-ft axial region to suppress the flux along the beltline. Since the depressed neutron flux in the region surrounding the hafnium absorbers alter the current response of the power range detectors, an evaluation of the fluence reduction strategy impact was undertaken to address the potential impact on the NIS power range detector performance and consequently the reactor protection system. This paper presents the results of that evaluation.

• OSTI ID: 5981848
• Report Number(s): CONF-910603--
• Conference Information: Journal Name: Transactions of the American Nuclear Society; (United States) Journal Volume: 63
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
210200* -- Power Reactors
Nonbreeding
Light-Water Moderated
Nonboiling Water Cooled
A CODES
AVAILABILITY
CALIBRATION
COMPUTER CODES
CONTAINERS
ELEMENTS
EMBRITTLEMENT
ENRICHED URANIUM REACTORS
FUEL ASSEMBLIES
FUEL MANAGEMENT
GUIDE TUBES
HAFNIUM
MEASURING INSTRUMENTS
METALS
NEUTRON ABSORBERS
NEUTRON DETECTORS
NEUTRON FLUENCE
NEUTRON LEAKAGE
OPERATION
PERFORMANCE
PHYSICAL RADIATION EFFECTS
POWER REACTORS
PRESSURE VESSELS
PWR TYPE REACTORS
RADIATION DETECTORS
RADIATION EFFECTS
REACTOR OPERATION
REACTOR PROTECTION SYSTEMS
REACTORS
SERVICE LIFE
THERMAL REACTORS
THREE-DIMENSIONAL CALCULATIONS
TRANSITION ELEMENTS
TUBES
WATER COOLED REACTORS
WATER MODERATED REACTORS
ZION-1 REACTOR
ZION-2 REACTOR