Rod insertion method analysis – A methodology update and comparison to boron dilution method

Merljak, Vid; Kromar, Marjan; Trkov, A.

doi:10.1016/j.anucene.2017.11.020

Cited by 10 publications

(4 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To enable safe operation of the nuclear reactor, it is important to know the exact value of the reactivity of the control rods. A newer method, called the rod insertion method (Trkov et al, 1995;Merljak et al, 2018) was developed in the Jožef Stefan Institute (JSI) Reactor Physics Department. It is based on the analysis of the reactor signal, measured by the ex-core power range neutron detectors, which is recorded during the continuous insertion of the control rod bank.…”

Section: Krško Nuclear Power Plantmentioning

confidence: 99%

“…The redistribution factors to the spatial redistribution of the neutron flux during the insertion of the control rod are studied in this work. The dynamic correction due to a temporal delay of the measured signal (the delayed neutron distribution is trailing behind the distribution of the prompt neutrons) (Merljak et al, 2018) is beyond the scope of this paper.…”

Section: Static Control Rod Worthmentioning

confidence: 99%

“…It can be measured by different methods: boron dilution method, rod insertion method, rod swap method, etc. The rod insertion method (Trkov et al, 1995;Merljak et al, 2018) was developed at the Reactor Physics Department of the Jožef Stefan Institute. It is based on the analysis of the power signal recorded with the ex-core neutron detectors during the continuous insertion of a control rod bank.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Determination of neutron flux redistribution factors for a typical pressurized water reactor ex-core measurements using Monte Carlo technique

et al. 2023

Self Cite

View full text Add to dashboard Cite

In a typical pressurized water reactor, neutron detectors located outside the reactor core monitor reactor power. In addition, they are also used to measure the reactivity of the control rods. A novel approach to calculate the ex-core neutron detector response in a typical pressurized water reactor using the Monte Carlo technique is presented. A detailed ex-core model of the Krško nuclear power plant was developed using the Monte Carlo neutron transport code MCNP. Due to the location of the ex-core neutron detectors, the hybrid code ADVANTG is used to generate variance reduction parameters to accelerte the convergence of the results outside the reactor core. To use ADVANTG, the fixed neutron source had to be reconstructed from the criticality core calculation. This paper presents the sensitivity analysis of the response of the ex-core detectors to the neutron data libraries used, the description of the fixed neutron source and the ADVANTG parameters. It was found that a pin-wise description of the neutron source for at least two rows of fuel assemblies at the core periphery is necessary for accurate results. Our results show the importance of a correct description of the prompt neutron spectra in the high energy region and the impact this has on the response of the ex-core detectors. The method in which the prompt neutron fission spectra for important fission nuclides are weighted by the calculated reaction rates has been shown to be the best approximation, with deviations from the reference calculation within statistical uncertainty. The effect of nuclear data libraries on the response of the ex-core detector was investigated, and the difference between the ENDF/B-VII.0 and the ENDF/B-VIII.0 nuclear data libraries was ∼11%. When the deficient evaluation of the 56Fe isotope included in the ENDF/B-VIII.0 nuclear data library was replaced by the improved evaluation from the IAEA INDEN project, the differences decreased to ∼3.7%. In addition, neutron flux redistributions due to control rod movement were investigated and flux redistribution factors were updated using Monte Carlo particle transport methods. The reaction rate redistribution factors obtained with methods presented in this paper are within 1% agreement with the currently used factors.

show abstract

Section: Krško Nuclear Power Plantmentioning

confidence: 99%

Section: Static Control Rod Worthmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Determination of neutron flux redistribution factors for a typical pressurized water reactor ex-core measurements using Monte Carlo technique

et al. 2023

Self Cite

View full text Add to dashboard Cite

show abstract

“…boron dilution and rod swap method). A newer method, called the rod insertion method [5], [6] was developed at the Jožef Stefan Institute (JSI) Reactor Physics Department. It relies on the analysis of the reactor signal, which is recorded during continuous insertion of the control rod bank.…”

Section: B Control Rod Calibrationmentioning

confidence: 99%

Predicting Ex-core Detector Response in a PWR with Monte Carlo Neutron Transport Methods

et al. 2020

Self Cite

View full text Add to dashboard Cite

An approach for calculating ex-core detector response using Monte Carlo code MCNP was developed. As a first step towards ex-core detector response prediction a detailed MCNP model of the reactor core was made. A script called McCord was developed as a link between deterministic program package CORD-2 and Monte Carlo code MCNP. It automatically generates an MCNP input from the CORD-2 data. A detailed MCNP core model was used to calculate 3D power distributions inside the core. Calculated power distributions were verified by comparison to the CORD-2 calculations, which is currently used for core design calculation verification of the Krško nuclea power plant. For the hot zero power configuration, the deviations are within 3 % for majority of fuel assemblies and slightly higher for fuel assemblies located at the core periphery. The computational model was further verified by comparing the calculated control rod worth to the CORD-2 results. The deviations were within 50 pcm and considered acceptable. The research will in future be supplemented with the in-core and ex-core detector signal calculations and neutron transport outside the reactor core.

show abstract

A fast online procedure of background current elimination from dynamic rod worth measurement

Bao

Yang

Xia

2021

Annals of Nuclear Energy

View full text Add to dashboard Cite

Rod insertion method analysis – A methodology update and comparison to boron dilution method

Cited by 10 publications

References 7 publications

Determination of neutron flux redistribution factors for a typical pressurized water reactor ex-core measurements using Monte Carlo technique

Determination of neutron flux redistribution factors for a typical pressurized water reactor ex-core measurements using Monte Carlo technique

Predicting Ex-core Detector Response in a PWR with Monte Carlo Neutron Transport Methods

A fast online procedure of background current elimination from dynamic rod worth measurement

Contact Info

Product

Resources

About