Release Rates of Short-lived Fission Gases from Modern Spherical Fuel Elements with TRISO-coated Particles

Abstract Measurement and prediction of fission product release is important in design, licensing and operation of HTRs. Latest development status is near zero particle manufacturing defects and in-pile failures combined with very low matrix contamination levels. In-pile Release over Birth rate measurements will be described and evaluated. Quantitative predictive analyses of short-lived gas release will be provided for MTR irradiation testing with a focus on the most recent experiment with Chinese fuel from HTR-PM production. For irradiation tests with no single particle failure, models describing particle kernel release are not applicable; instead modeling of matrix contamination release is essential. Good agreement between post calculations and in-line R/B measurements has been achieved.

Download Full-text

Post Irradiation Examination of HTR Fuel at ITU Karlruhe

Fourth International Topical Meeting on High Temperature Reactor Technology, Volume 2 ◽

10.1115/htr2008-58329 ◽

2008 ◽

Author(s):

D. Freis ◽

P. D. Bottomley ◽

J.-P. Hiernaut ◽

J.-Y. Colle ◽

J. Ejton ◽

...

Keyword(s):

High Temperature ◽

Hardness Testing ◽

Cold Finger ◽

Safety Testing ◽

Coated Particles ◽

Product Release ◽

High Temperature Reactor ◽

Accident Scenarios ◽

Under Construction ◽

Fuel Elements

In the last years considerable efforts have been made at the Institute for Transuranium Elements (ITU) in order to reestablish European knowledge and ability in safety testing of irradiated high temperature reactor (HTR) Fuel Elements. In the framework of the 6th European framework programme a cold finger apparatus (Ku¨FA) furnace, formerly installed at FZ-Ju¨lich (FzJ), has been installed in a hot cell at ITU [Freis 2008] in order to test fission product release under high temperature and non-oxidising conditions. Several analytical methods (e.g. Gamma-spectrometry, mass-spectrometry) have been applied in order to analyse different isotopes released during Ku¨FA tests. After the heating tests, examinations of the fuel elements were performed including scanning electron microscopy (SEM) and micro-hardness testing of coated particles. Individual coated particles were object of heating tests in a Knudsen cell with a coupled mass spectrometer measuring all released species. In order to cover more accident scenarios, a second furnace for oxidising-conditions (air- or water-ingress) was constructed and installed in a cold lab. Furthermore a disintegration apparatus, based on anodic oxidation, was constructed and fuel elements were dissolved obtaining thousands of individual coated particles for further examination. A fully automated irradiated microsphere gamma analyzer (IMGA) is under construction and will be used, in particular, to identify and sort out failed particles.

Download Full-text

Fission Product Release from Coated Particles Embedded in Spherical Fuel Elements for High-Temperature Reactors

Nuclear Technology ◽

10.13182/nt77-a31911 ◽

1977 ◽

Vol 35 (2) ◽

pp. 509-515 ◽

Cited By ~ 4

Author(s):

E. Groos ◽

G. Mielken ◽

R. Duwe ◽

A. Müller ◽

M. Will

Keyword(s):

High Temperature ◽

Fission Product ◽

Coated Particles ◽

Product Release ◽

High Temperature Reactors ◽

Fuel Elements

Download Full-text

Gas release rates and properties from Lithium Cobalt Oxide lithium ion battery arrays

Journal of Power Sources ◽

10.1016/j.jpowsour.2020.229388 ◽

2021 ◽

Vol 487 ◽

pp. 229388

Author(s):

Robert W. Kennedy ◽

Kevin C. Marr ◽

Ofodike A. Ezekoye

Keyword(s):

Lithium Ion Battery ◽

Cobalt Oxide ◽

Lithium Ion ◽

Lithium Cobalt Oxide ◽

Gas Release ◽

Release Rates ◽

Lithium Cobalt

Download Full-text

Pellet-Cladding Interaction of LMFBR Fuel Elements at Unsteady State: An Introduction to Computer Code ISUNE-5

Journal of Engineering for Power ◽

10.1115/1.3230785 ◽

1981 ◽

Vol 103 (4) ◽

pp. 627-636 ◽

Cited By ~ 1

Author(s):

B. M. Ma

Keyword(s):

Reactor Core ◽

Fatigue Cracking ◽

Computer Code ◽

Fuel Burnup ◽

Fuel Pellet ◽

Gas Release ◽

Unsteady State ◽

Fission Gas ◽

Fuel Elements ◽

Fission Gas Release

The fuel pellet-cladding interaction (PCI) of liquid-metal fast breeder reactor (LMFBR) fuel elements or fuel rods at unsteady state is analyzed and discussed based on experimental results. In the analyses, the heat generation, fuel restructuring, temperature distribution, gap conductance, irradiation swelling, irradiation creep, fuel burnup, fission gas release, fuel pellet cracking, crack healing, cladding cracking, yield failure and fracture failure of the fuel elements are taken into consideration. To improve the sintered (U,Pu)O2 fuel performance and reactor core safety at high temperature and fuel burnup, it is desirable to (a) increase and maintain the ductility of cladding material, (b) provide sufficient gap thickness and plenum space for accommodating fission gas release, (c) keep ramps-power increase rate slow and gentle, and (d) reduce the intensity and frequency of transient PCI in order to avoid intense stress fatigue cracking (SFC) and stress corrosion cracking (SCC) due to fission product compounds CsI, CdI2, Cs2Te, etc. at the inner cladding surface of the fuel elements during PCI.

Download Full-text

Volcanology: Volcanic gas release rates

Nature ◽

10.1038/313266a0 ◽

1985 ◽

Vol 313 (6000) ◽

pp. 266-266 ◽

Cited By ~ 2

Author(s):

Lionel Wilson

Keyword(s):

Gas Release ◽

Release Rates ◽

Volcanic Gas

Download Full-text

Fabrication, Properties and Irradiation Performance of Molded Block Fuel Elements for HTGRs

Fourth International Topical Meeting on High Temperature Reactor Technology, Volume 2 ◽

10.1115/htr2008-58025 ◽

2008 ◽

Cited By ~ 1

Author(s):

Milan F. Hrovat ◽

Karl-H. Grosse ◽

Richard Seemann

Keyword(s):

Coated Particles ◽

Cooling Channels ◽

Block Form ◽

Graphite Matrix ◽

Demonstration Plant ◽

Irradiation Performance ◽

Fuel Elements ◽

Monolithic Structure ◽

Very High ◽

Crystalline Graphite

The molded block fuel element (FE) also called monolith is a molded body, consisting of a substantially isotropic highly crystalline graphite matrix, fuel regions within the same matrix and cooling channels. The fuel regions contain the fuel in the form of coated particles which are well bonded to the remaining graphite matrix, so that both parts of the block form a monolithic structure. The monolith meets the requirements for the very high temperature reactors attaining helium outlet temperatures above 1000°C. To fabricate the molded blocks FE demonstration plant was erected and put into operation. The equipment worked without malfunction. The produced block FEs meet the specifications of GA machined block FEs. All specimens and block segments irradiated at temperature up to 1600°C and max. fast fluence E > 0, 1 MeV of 11×1021 n/cm2 show perfect behaviour without any damage.

Download Full-text