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Title: A NOVEL TECHNIQUE APPLYING SPECTRAL ESTIMATION TO JOHNSON NOISE THERMOMETRY

Abstract

Johnson noise thermometry (JNT) is one of many important measurements used to monitor the safety levels and stability in a nuclear reactor. However, this measurement is very dependent on the electromagnetic environment. Properly removing unwanted electromagnetic interference (EMI) is critical for accurate drift free temperature measurements. The two techniques developed by Oak Ridge National Laboratory (ORNL) to remove transient and periodic EMI are briefly discussed in this document. Spectral estimation is a key component in the signal processing algorithm utilized for EMI removal and temperature calculation. Applying these techniques requires the simple addition of the electronics and signal processing to existing resistive thermometers.

Authors:
 [1];  [1];  [1];  [1];  [1];  [1];  [1]
  1. ORNL
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1356928
DOE Contract Number:
AC05-00OR22725
Resource Type:
Conference
Resource Relation:
Conference: 10th International Embedded Topical Meeting on Nuclear Plant Instrumentation, Control & Human-Machine Interface Technologies (NPIC & HMIT 2017), San Francisco, CA, USA, 20170611, 20170615
Country of Publication:
United States
Language:
English

Citation Formats

Ezell, N Dianne Bull, Britton Jr, Charles L, Roberts, Michael, Holcomb, David Eugene, Ericson, Milton Nance, Djouadi, Seddik M, and Wood, Richard Thomas. A NOVEL TECHNIQUE APPLYING SPECTRAL ESTIMATION TO JOHNSON NOISE THERMOMETRY. United States: N. p., 2017. Web.
Ezell, N Dianne Bull, Britton Jr, Charles L, Roberts, Michael, Holcomb, David Eugene, Ericson, Milton Nance, Djouadi, Seddik M, & Wood, Richard Thomas. A NOVEL TECHNIQUE APPLYING SPECTRAL ESTIMATION TO JOHNSON NOISE THERMOMETRY. United States.
Ezell, N Dianne Bull, Britton Jr, Charles L, Roberts, Michael, Holcomb, David Eugene, Ericson, Milton Nance, Djouadi, Seddik M, and Wood, Richard Thomas. Sun . "A NOVEL TECHNIQUE APPLYING SPECTRAL ESTIMATION TO JOHNSON NOISE THERMOMETRY". United States. doi:.
@article{osti_1356928,
title = {A NOVEL TECHNIQUE APPLYING SPECTRAL ESTIMATION TO JOHNSON NOISE THERMOMETRY},
author = {Ezell, N Dianne Bull and Britton Jr, Charles L and Roberts, Michael and Holcomb, David Eugene and Ericson, Milton Nance and Djouadi, Seddik M and Wood, Richard Thomas},
abstractNote = {Johnson noise thermometry (JNT) is one of many important measurements used to monitor the safety levels and stability in a nuclear reactor. However, this measurement is very dependent on the electromagnetic environment. Properly removing unwanted electromagnetic interference (EMI) is critical for accurate drift free temperature measurements. The two techniques developed by Oak Ridge National Laboratory (ORNL) to remove transient and periodic EMI are briefly discussed in this document. Spectral estimation is a key component in the signal processing algorithm utilized for EMI removal and temperature calculation. Applying these techniques requires the simple addition of the electronics and signal processing to existing resistive thermometers.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Sun Jan 01 00:00:00 EST 2017},
month = {Sun Jan 01 00:00:00 EST 2017}
}

Conference:
Other availability
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  • Johnson noise thermometry is one of many important measurement techniques used to monitor the safety levels and stability in a nuclear reactor. However, this measurement is very dependent on the minimal electromagnetic environment. Properly removing unwanted electromagnetic interference (EMI) is critical for accurate drift-free temperature measurements. The two techniques developed by Oak Ridge National Laboratory (ORNL) to remove transient and periodic EMI are briefly discussed here. Spectral estimation is a key component in the signal processing algorithm used for EMI removal and temperature calculation. The cross-power spectral density is a key component in the Johnson noise temperature computation. Applying eithermore » technique requires the simple addition of electronics and signal processing to existing resistive thermometers. With minimal installation changes, the system discussed here can be installed on existing nuclear power plants. The Johnson noise system developed is tested at three locations: ORNL, Sandia National Laboratory, and the Tennessee Valley Authority’s Kingston Fossil Plant. Each of these locations enabled improvement on the EMI removal algorithm. Finally, the conclusions made from the results at each of these locations is discussed, as well as possible future work.« less
  • In order for Johnson Noise Thermometry (JNT) to be beneficial to SMR designers, it must offer advantages beyond the current state-of-the-art technology. Comparisons to traditional RTDs and thermocouples will involve life-cycle costs, installation footprint, reliability, and accuracy. With JNT, there is additional equipment beyond what is required for the traditional RTD measurement. Therefore, the JNT-RTD system will involve additional complexity and this additional complexity must be justified. Operators will want to know that the measurement is reliable and trustworthy. It is also important that the sensor involve little, if any, additional ongoing maintenance work and that it has a lowmore » probability of causing any malfunction of the primary measurement channel. If these features can be successfully demonstrated, the JNT-RTD system could potentially save money and increase plant reliability.« less
  • Rhenium ultrasonic (UST) and Johnson noise (JNT) thermometers were used to measure fuel centerline temperatures of 900--1500$sup 0$C in capsules irradiated in the HFIR for periods of 1000--3000 hrs. Transmutation of rhenium by thermal neutron absorption caused large drifts in UST calibration but none in JNT calibration. Whole capsule, post irradiation calibration was used to measure drift in UST and to provide a calibration correction. Calculation of the temperature and the resistance of JNT rhenium sensor elements by noise power measurements have shown no temperature drift in over 1100 hrs at 1250$sup 0$C. Performance of W--Re thermocouples UST and JNTmore » in fuel irradiation centerline thermometry is compared. (auth)« less
  • A temperature transducer fabricated of tungsten-rhenium thermocouple elements terminated in a rhenium coil acts as a dual temperature measuring device due to both a dc output from the thermocouple elements and a thermally-generated noise emitted from the rhenium coil. In performed tests, a bare wire thermocouple in close proximity to the test transducer acted as the reference temperature measuring device. Comparisons of the JNPT and the reference at temperatures up to 1500/sup 0/C generally yielded agreement within 4% of reading. However, because of reduced insulation resistance and interference due to spurious (non-thermal) noise, the JNPT transducer exhibited increasingly inaccurate temperaturemore » measurements above 1500/sup 0/C. Hafnia- and beryllia-insulated transducers were fabricated for these tests. At all temperatures, beryllia yielded a higher insulation resistance by a factor of 10.« less