Logo: to the web site of Uppsala University

uu.sePublikasjoner fra Uppsala universitet
Endre søk
RefereraExporteraLink to record
Permanent link

Direct link
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
LOKET- a Gamma-ray Spectroscopy System for In-pool Measurements of Thermal Power Distribution in Nuclear Fuel
Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för kärn- och partikelfysik, Avdelningen för kärnfysik.
Inngår i: Nucl. Instrum. Meth. AArtikkel i tidsskrift (Fagfellevurdert) Submitted
Identifikatorer
URN: urn:nbn:se:uu:diva-94565OAI: oai:DiVA.org:uu-94565DiVA, id: diva2:168453
Tilgjengelig fra: 2006-05-16 Laget: 2006-05-16bibliografisk kontrollert
Inngår i avhandling
1. Studies of Nuclear Fuel Performance Using On-site Gamma-ray Spectroscopy and In-pile Measurements
Åpne denne publikasjonen i ny fane eller vindu >>Studies of Nuclear Fuel Performance Using On-site Gamma-ray Spectroscopy and In-pile Measurements
2006 (engelsk)Doktoravhandling, med artikler (Annet vitenskapelig)
Abstract [en]

Presently there is a clear trend of increasing demands on in-pile performance of nuclear fuel. Higher target burnups, part length rods and various fuel additives are some examples of this trend. Together with an increasing demand from the public for even safer nuclear power utilisation, this implies an increased focus on various experimental, preferably non-destructive, methods to characterise the fuel.

This thesis focuses on the development and experimental evaluation of such methods. In its first part, the thesis presents a method based on gamma-ray spectroscopy with germanium detectors that have been used at various power reactors in Europe. The aim with these measurements is to provide information about the thermal power distribution within fuel assemblies in order to validate core physics production codes. The early closure of the Barsebäck 1 BWR offered a unique opportunity to perform such validations before complete depletion of burnable absorbers in Gd-rods had taken place. To facilitate the measurements, a completely submersible measuring system, LOKET, was developed allowing for convenient in-pool measurements to be performed.

In its second part, the thesis describes methods that utilise in-pile measurements. These methods have been used in the Halden test-reactor for determination of fission gas release, pellet-cladding interaction studies and fuel development studies.

Apart from the power measurements, the LOKET device has been used for fission gas release (FGR) measurements on single fuel rods. The significant reduction in fission gas release in the modern fuel designs, in comparison with older designs, has been demonstrated in a series of experiments. A FGR database covering a wide range of burnup, power histories and fuel designs has been compiled and used for fuel performance analysis. The fission gas release has been measured on fuel rods with average burnups well above 60 MWd/kgU. The comparison between core physics calculations (PHOENIX-4/POLCA-7) and the in-pool measurements of thermal power indicates that the nodal power can generally be predicted with an accuracy within 4% and the bundle power with an accuracy better than 2%, expressed as rms errors.

In-pile experiments have successfully simulated the conditions that occur in a fuel rod following a primary debris failure, being secondary fuel degradation. It was concluded that massive hydrogen pick-up takes place during the first few days following the primary failure and that a pre-oxidized layer does not function as a barrier towards hydriding in an environment with a very high partial pressure of hydrogen. Another series of in-pile experiments clearly indicate that increased UO2 grain size is an effective way of suppressing fission gas release in LWR fuel up to the burnup level covered (55 MWd/kgUO2).

sted, utgiver, år, opplag, sider
Uppsala: Acta Universitatis Upsaliensis, 2006. s. 103
Serie
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1651-6214 ; 191
Emneord
Nuclear physics, fission gas release, nuclear fuel, core physics, gamma-ray spectroscopy, LOKET, thermal power, burnup, fuel failure, validation, cladding, Kärnfysik
Identifikatorer
urn:nbn:se:uu:diva-6912 (URN)91-554-6582-X (ISBN)
Disputas
2006-06-07, Sal 2001, Ångströmlaboratoriet, Lägerhyddsvägen 1, Uppsala, 13:30
Opponent
Veileder
Tilgjengelig fra: 2006-05-16 Laget: 2006-05-16 Sist oppdatert: 2021-06-18bibliografisk kontrollert

Open Access i DiVA

Fulltekst mangler i DiVA

Av organisasjonen

Søk utenfor DiVA

GoogleGoogle Scholar

urn-nbn

Altmetric

urn-nbn
Totalt: 635 treff
RefereraExporteraLink to record
Permanent link

Direct link
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf