Neutron Measurements at Nuclear Power Reactors[55]

Journal Article · Sat Dec 01 04:00:00 EST 2001 · Nuclear Instruments and Methods in Physics Research. Section A, Accelerators, Spectrometers, Detectors and Associated Equipment

OSTI ID:15001200

Scherpelz, Robert I ^[1]; Tanner, Jennifer E ^[1]

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1. BATTELLE (PACIFIC NW LAB)

Staff from the Pacific Northwest National Laboratory (PNNL, operated by Battelle Memorial Institute), have performed neutron measurements at a number of commercial nuclear power plants in the United States. Neutron radiation fields at light water reactor (LWR) power plants are typically characterized by low-energy distributions due to the presence of large amounts of scattering material such as water and concrete. These low-energy distributions make it difficult to accurately monitor personnel exposures, since most survey meters and dosimeters are calibrated to higher energy fields such as those produced by bare or D2O-moderated 252Cf sources. Commercial plants typically use thermoluminescent dosimeters (TLDs) in an albedo configuration for personnel dosimetry and survey meters based on a thermal-neutron detector inside a cylindrical or spherical moderator for dose rate assessment, so their methods of routine monitoring are highly dependent on the energy of the neutron fields. Battelle has participated in neutron assessments at a number of LWR facilities to characterize neutron radiation fields and to evaluate the responses of plant dosimeters and survey instruments. In these studies the tissue equivalent proportional counter (TEPC) was relied on as the primary instrument for measuring neutron dose and dose equivalent rates, and 3He and multisphere spectrometers were used to measure energy distributions. The use of these instruments in LWR work locations is usually difficult because of extreme environmental conditions such as high temperatures. These studies have confirmed the presence of low-energy neutron fields in most work locations. The studies have also found that albedo dosimeters used at power plants typically over-respond by factors of four or more when using a calibration based on californium exposures. Survey instruments also respond high, usually by at least a factor of two, in typical LWR environments.

• Research Organization: Pacific Northwest National Lab., Richland, WA (US)
• Sponsoring Organization: US Department of Energy (US)
• DOE Contract Number: AC06-76RL01830
• OSTI ID: 15001200
• Report Number(s): PNWD-SA-5110
• Journal Information: Nuclear Instruments and Methods in Physics Research. Section A, Accelerators, Spectrometers, Detectors and Associated Equipment, Journal Name: Nuclear Instruments and Methods in Physics Research. Section A, Accelerators, Spectrometers, Detectors and Associated Equipment Journal Issue: 1-2 Vol. 476
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
29 ENERGY PLANNING, POLICY, AND ECONOMY
CALIBRATION
CALIFORNIUM
DOSE EQUIVALENTS
DOSE RATES
DOSEMETERS
ENERGY SPECTRA
NEUTRON
SPECTROMETRY
RADIATION PROTECTION
NEUTRONS
NUCLEAR POWER
NUCLEAR POWER PLANTS
PERSONNEL DOSIMETRY
POWER PLANTS
PROPORTIONAL COUNTERS
RADIATIONS