Study on improvement of reactor physics analysis method for FBRs with various core concept

*; Kitada, Takanori*; Tagawa, Akihiro; *; Takeda, Toshikazu*

JNC TJ9400 2000-006, 272 Pages, 2000/02

JNC-TJ9400-2000-006.pdf:9.69MB

Investigation was made on the follwing three themes as a part of the improvement of reactor physics analysis method for FBR with various core concept. Part 1: Investigation of Error Estimation of Neutron Spectra in FBR and Suggestions to Improve the Accuracy. In order to improve the spectrum unfolding method used in fast experimental reactor JOYO, a trial was made to evaluate the error in the estimated neutron spectrum, cause by cause. And the evaluated errors were summed up to obtain the most probable and reasonable error as possible. The summed up error was found relatively small compared to the error caused by the uncertainty of cross section data: most of the error in the spectrum unfolding method can be attributed to the error in cross sections. It was also found that the error due to the fission spectrum causes a considerable error in the high energy neutron spectrum which is over several MeV. Part 2: Study on Reactor Physics Analysis Method for Gas-Cooled FBR. In gas-cooled FBR, the portion of coolant channels in core volume is larger than sodium-cooled FBR. This leads to strong neutron streaming effects. For sodium-cooled FBR, several methods were proposed to evaluate the neutron streaming effect, however, these methods can not be used directly to gas-cooled reactor because the direction dependent diffusion coefficient becomes infinitive along the direction pararel to the coolant chammel. In this study, a new method is proposed to evaluate the neutron streaming effect, based on the method taking the axial buckling into consideration, which method was originally proposed by Khler. Part 3: Study on Reactor Physics Analysis Method for Water-Cooled FBR An investigation was made on low-moderated water-cooled FBR, on the point that the ordinary used analysis method for FBR may give considerable difference in results in such core. In light water reactors, it is well known that the space dependence of self-shielding effect of heavy nuclides are considerably ...

An Adjusted Cross Section Library for DFBR

Peter, J. Collins

PNC TN9410 97-034, 35 Pages, 1997/04

PNC-TN9410-97-034.pdf:1.07MB

While in the Reactor Physics Research Section of the Advanced Technology Division at OEC, I participated in the project to construct a data library for the demonstration fast breeder reactor (DFBR). This library would be produced using a combination of evaluated differential cross sections together with integral experimental data for fast reactors, so as to assure sufficiently accurate calculations for the DFBR designs. I had much experience of the design and use of experiments for the large-size cores at ZPPR under the title JUPITER which was performed under the USDOE/PNC joint agreement. My contribution here was mainly in extension of the experimental database to include the very-hard spectrum fast criticals from the Los Alamos National Laboratory (LANL). The data for these cores are described. Our work at ANLW with the GMADJ code, which is similar in effect to the ABLE code that we use at PNC, showed why many experiments are important in this project as well as those in the more obvious Pu/U oxide conventional cores which are of current interest for the DFBR. This point was not appreciated at PNC and is discussed here. The data from the fast spectrum critical experiments made at Los Alamos are described together with information that I have been able to find concerning the uncertainties. The main interest is these experiments has been for prediction of criticality. Consequently, the full covariance information that we would like has not been published. However, the uncertainty in the fuel content is, by far, the major contributor to the uncertainty. The LANL experiments have been a principal leg of the data testing for fast reactors for all versions of ENDF/B in the US. For our work, they provide measurements at Mev energies which are not available from the experiments in the softer-spectrum of the LMFBR.

Flow rate measurement of buoyancy-driven exchange flow by laser Doppler velocimeter

Fumizawa, Motoo; Hishida, Makoto

Laser Anemometry 1995 (FED-Vol. 229), 0, p.51 - 56, 1995/00

no abstracts in English

Approximation formulae of integral for making a discrete-time model

Keisoku Jido Seigyo Gakkai Rombunshu, 19(2), p.182 - 184, 1983/00

http://joi.jlc.jst.go.jp/JST.Journalarchive/sicetr1965/6.182

no abstracts in English

DREAM-FLOW:A Computer Proguram for Estimating the Uncertainty of Channel Coolant Flow Rates of HTGR's Core Due to the Monte Carlo Method

;

JAERI-M 7059, 57 Pages, 1977/04

JAERI-M-7059.pdf:1.64MB

no abstracts in English

Statistical error estimation and bias correction in Monte Carlo criticality calculation

Ueki, Taro

no journal, , 

It is essential to examine performance limit in the development of statistical analysis methodology. In this work, we report the performance evaluation of statistical error estimation and bias correction in the Monte Carlo criticality calculation of an extreme version of the k-effective-of-the world problem.