Neutron dosimetry at commercial nuclear plants: Final report of Subtask D: TEPC (tissue-equivalent proportional counter) feasibility

Technical Report · Wed Oct 01 04:00:00 EDT 1986

OSTI ID:7149597

Cummings, F M; Haggard, D L; Endres, G W.R.

The feasibility of routinely determining the neutron dose equivalent rates inside commercial nuclear power plants using a microprocessor-controlled, miniaturized tissue-equivalent proportional counter (mini-TEPC) was evaluated during the 1984 and 1985 fiscal years. Two mini-TEPCs, one with a 2-inch- and another with a 5-inch-diameter spherical detector, were tested. The responses of the mini-TEPCs were evaluated for effects resulting from temperature, energy distribution of monoenergetic neutron beams, and broadly distributed energy spectra from moderated sources. In addition, the mini-TEPCs were tested inside the containment of an operating pressurized water reactor. No trends were noted in the response of the mini-TEPCs for monoenergetic (above 200 keV) and broad-beam neutron irradiations. When tested in an environmental chamber and inside containment of a pressurized water reactor, the mini-TEPCs exhibited severe depressions of response as a function of temperature. However, the determination of neutron dose equivalent using the laboratory-scale TEPC was accurate and stable during the temperature study. The response from the mini-TEPC decreased with higher temperature because the temperature affected the built-in electronics and the detector's gas gain. The mini-TEPCs tested in this study did not have mechanisms for adjusting the proton drop point to compensate for the decreased gas gain. It is recommended that the temperature-dependent response problems of the mini-TEPC be rectified before it is used as a neutron-monitoring instrument inside reactor containment.

• Research Organization: Pacific Northwest Lab., Richland, WA (USA)
• DOE Contract Number: AC06-76RL01830
• OSTI ID: 7149597
• Report Number(s): NUREG/CR-4743; PNL-6014; ON: TI87002355
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
220900 -- Nuclear Reactor Technology-- Reactor Safety
440102* -- Radiation Instrumentation-- Radiation Dosemeters
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
61 RADIATION PROTECTION AND DOSIMETRY
655003 -- Medical Physics-- Dosimetry
CONTAINMENT
DOSE-RESPONSE RELATIONSHIPS
DOSIMETRY
MATERIALS
MEASURING INSTRUMENTS
NEUTRON DOSIMETRY
NUCLEAR FACILITIES
NUCLEAR POWER PLANTS
POWER PLANTS
POWER REACTORS
PROPORTIONAL COUNTERS
RADIATION DETECTORS
REACTORS
TEMPERATURE DEPENDENCE
THERMAL POWER PLANTS
TISSUE-EQUIVALENT MATERIALS