Estimation of Clearance Potential Index and Hazard Factors of CANDU Fuel Bundle and Its Validation Based on the Measurements of Radioisotopes Inventories From Pickering Reactor Fuel

2007 ◽  
Author(s):  
Alexandru Octavian Pavelescu ◽  
Dan Gabriel Cepraga ◽  
Konstantina Voukelatou ◽  
Renato Tinti
Keyword(s):  
Cross Sections ◽  
Spent Nuclear Fuel ◽  
Safety Management ◽  
Fission Products ◽  
Radioactive Wastes ◽  
Radioactive Material ◽  
Complex Activity ◽  
Potential Index ◽  
Fuel Bundle ◽  
Biological Hazard

This paper is related to the clearance potential levels, ingestion and inhalation hazard factors of the spent nuclear fuel and radioactive wastes. This study required a complex activity that consisted of more steps such as: the acquisition, setting up, validation and application of procedures, codes and libraries. The paper reflects the validation stage of this study. Its objective was to compare the measured inventories of selected actinide and fission products radionuclides in an element from the Pickering CANDU reactor with the inventories predicted using a recent version of the SCALE 5\ORIGEN-ARP code coupled with the time dependent cross sections library for the CANDU 28 reactor (produced by the sequence SCALE4.4a\SAS2H and SCALE4.4a\ORIGEN-S). In this way, the procedures, the codes and the libraries for the characterization of radioactive material in terms of radioactive inventories, clearance, and biological hazard factors could be qualified and validated, in support of the safety management of the radioactive wastes.

Handling spent nuclear fuel and radioactive wastes on the shore servicing base in Gremikha

Atomic Energy ◽  
2006 ◽  
Vol 101 (1) ◽  
pp. 517-520
Author(s):  
V. A. Pavlov ◽  
B. P. Papkovskii ◽  
E. N. Samarin ◽  
B. S. Stepennov ◽  
A. F. Usatyi ◽  
...  
Keyword(s):  
Nuclear Fuel ◽  
Spent Nuclear Fuel ◽  
Radioactive Wastes

Leaching of Used Candu Fuel: Results from a 19-Year Leach Test Under Oxidizing Conditions

1996 ◽  
Vol 465 ◽  
Author(s):  
S. Stroes-Gascoyne ◽  
L. H. Johnson ◽  
J. C. Tait ◽  
J. L. McConnell ◽  
R. J. Porth
Keyword(s):  
Grain Boundary ◽  
Cross Sections ◽  
Peak Power ◽  
Physical State ◽  
Fuel Pellet ◽  
Fuel Surface ◽  
Pellet Surface ◽  
Fuel Bundle ◽  
Dissolution Behaviour ◽  
Congruent Dissolution

ABSTRACTA fuel leaching experiment has been in progress since 1977 to study the dissolution behaviour of used CANDU fuel in aerated aqueous solution. The experiment involves exposure of 50-mm clad segments of an outer element of a Pickering fuel bundle (burnup 610 GJ/kg U; linear and peak power ratings 53 and 58 kW/m, respectively), to deionized distilled water (DDH2O, ∼2 mg/L carbonate) and tapwater (∼50 mg/L carbonate). In 1992, it was observed that the fuel in at least one of the leaching solutions showed some signs of deterioration and, therefore, in 1993, parts of the fuel samples were sacrificed for a detailed analysis of the physical state of the fuel, using SEM and optical microscopy. Leaching results to date show that even after >6900 days only 5 to 7.7% of the total calculated inventory of 137Cs has leached out preferentially and that leach rates suggest a development towards congruent dissolution. Total amounts of 137Cs and 90Sr leached are slightly larger in tapwater than in DDH2O. SEM examinations of leached fuel surface fragments indicate that the fuel surface exposed to DDH2O is covered in a needle-like precipitate. The fuel surface exposed to tapwater shows evidence of leaching but no precipitate, likely because uranium is kept in solution by carbonate. Detailed optical and SEM microscopy examinations on fuel cross sections suggest that grain-boundary dissolution in DDH2O is not prevalent, and in tapwater appears to be limited to the outer %0.5 mm (pellet/cladding) region of the fuel. Grain boundary attack seems to be limited to microcracks at or near the surface of the fuel. It thus appears that grain-boundary attack occurs only near the fuel pellet surface and is prevalent only in the presence of carbonate in solution.

Conceptual Study of Neutron Physics of Nuclear Fuel Cycle for Ceramic Fast Reactor

2021 ◽  
Author(s):  
Xuesong Yan ◽  
Yaling Zhang ◽  
Yucui Gao ◽  
Lei Yang
Keyword(s):  
High Temperature ◽  
Nuclear Fuel ◽  
Fast Reactor ◽  
Spent Nuclear Fuel ◽  
Fuel Cycle ◽  
Fission Products ◽  
Nuclear Fuel Cycle ◽  
Purification Method ◽  
Neutron Physics ◽  
Conceptual Study

Abstract To make the nuclear fuel cycle more economical and convenient, as well as prevent nuclear proliferation, the conceptual study of a simple high-temperature dry reprocessing of spent nuclear fuel (SNF) for a ceramic fast reactor is proposed in this paper. This simple high-temperature dry (HT-dry) reprocessing includes the Atomics International Reduction Oxidation (AIROX) process and purification method for rare-earth elements. After removing the part of fission products from SNF by a HT-dry reprocessing without fine separation, the remaining nuclides and some uranium are fabricated into fresh fuel which can be used back to the ceramic fast reactor. Based on the ceramic coolant fast reactor, we studied neutron physics of nuclear fuel cycle which consists operation of ceramic reactor, removing part of fission products from SNF and preparation of fresh fuels for many time. The parameters of the study include effective multiplication factor (Keff), beam density, and nuclide mass for different ways to remove the fission products from SNF. With the increase in burnup time, the trend of increasing 239Pu gradually slows down, and the trend of 235U gradually decreases and become balanced. For multiple removal of part of fission products in the nuclear fuel cycle, the higher the removal, the larger the initial Keff.

TEM Analysis of Corrosion Products From a Radioactive Stainless Steel-based Alloy

2000 ◽  
Vol 6 (S2) ◽  
pp. 368-369
Author(s):  
N.L. Dietz ◽  
D.D Keiser
Keyword(s):  
Stainless Steel ◽  
Spent Nuclear Fuel ◽  
National Laboratory ◽  
Argonne National Laboratory ◽  
Fission Products ◽  
Waste Form ◽  
Metallic Sodium ◽  
Geologic Repository ◽  
Tem Analysis ◽  
Waste Forms

Argonne National Laboratory has developed an electrometallurgical treatment process for metallic spent nuclear fuel from the Experimental Breeder Reactor-II. This process stabilizes metallic sodium and separates usable uranium from fission products and transuranic elements that are contained in the fuel. The fission products and other waste constituents are placed into two waste forms: a ceramic waste form that contains the transuranic elements and active fission products such as Cs, Sr, I and the rare earth elements, and a metal alloy waste form composed primarily of stainless steel (SS), from claddings hulls and reactor hardware, and ∼15 wt.% Zr (from the U-Zr and U-Pu-Zr alloy fuels). The metal waste form (MWF) also contains noble metal fission products (Tc, Nb, Ru, Rh, Te, Ag, Pd, Mo) and minor amounts of actinides. Both waste forms are intended for eventual disposal in a geologic repository.

Approach to Derivation of Waste Acceptance Criteria for Mochovce Disposal Facility

2003 ◽  
Author(s):  
V. Hanusˇi´k ◽  
Z. Kusovska´ ◽  
J. Bala´zˇ ◽  
A. Mrsˇkova´
Keyword(s):  
Fission Products ◽  
Total Activity ◽  
Safety Analysis ◽  
Radioactive Wastes ◽  
Primary Circuit ◽  
Radiological Protection ◽  
Waste Streams ◽  
Acceptance Criteria ◽  
Near Surface ◽  
Dose Limits

In Slovakia, low and intermediate level radioactive wastes are disposed in a near-surface repository at Mochovce site. The repository, which was commissioned in September 2001, has a disposal capacity 22,320 m3. It is a vault-type concrete structure repository with reinforced concrete containers as the final waste packages. The Mochovce repository is designed to receive acceptable radioactive wastes from decommissioned A-1 power plant at Jaslovske´ Bohunice, operational waste from NPPs V-1 and V-2 at Jaslovske´ Bohunice site and NPP Mochovce, as well as institutional radioactive wastes. Generally, calculation endpoint of disposal facilities performance assessment is radiological impact on humans and environment. In that case, starting points of assessment are the waste activity concentrations and inventory activity. The acceptance of radioactive waste in Mochovce repository is one of the many elements that directly contribute to the safety of the disposal system. In Mochovce repository safety analysis, end points are both the concentration per package and total activity values. On the other hand, radiological protection criteria are the starting points of the calculation. This approach was developed and applied because the actual inventory that will be disposed of is highly uncertain. As a result of the accidents, the primary circuit was contaminated by fission products. Some auxiliary circuits and facilities were also contaminated. The complicated problem is the relatively high content of long-lived radionuclides (inclusive transuranic elements) in some waste streams. After two technological incidents at NPP A-1 uncertainties in waste inventory are large because of variability in the types of waste streams and variability in the quality and completeness of the waste characterization data. This paper presents the philosophy of safety analysis, development of scenarios, their modelling and approach that have been used to derive waste acceptance criteria, specifically limits of activity. The approach consists of the determination of radionuclides important for safety, the use of relevant safety scenarios, the setting of dose limits associated with scenarios, the calculation of activity limits and application of the simple summation rule. Finally, information is provided about short operation of the repository.

Severe Transportation Accidents: Impacts of Severe Fires on Radioactive Material Transportation

2009 ◽  
Author(s):  
Christopher S. Bajwa ◽  
Earl P. Easton ◽  
Darrell S. Dunn
Keyword(s):  
Spent Nuclear Fuel ◽  
Nuclear Regulatory Commission ◽  
Radioactive Material ◽  
Fire Investigation ◽  
Radioactive Materials ◽  
The Us ◽  
Material Transportation ◽  
Safe Transport ◽  
Regulatory Commission ◽  
Loss Of Strength

In 2007, a severe transportation accident occurred in Oakland, California in what is commonly known as the “MacArthur Maze” section of Interstate 580 (I-580). The accident involved a tractor trailer carrying gasoline that impacted an overpass support column and burst into flames. The subsequent fire burned for over 2 hours and led to the collapse of the overpass due to the loss of strength in the structural steel that supported the overpass. The US Nuclear Regulatory Commission (NRC) studied this accident to examine any potential regulatory implications related to the safe transport of radioactive materials, including spent nuclear fuel. This paper will discuss the details of the NRC’s MacArthur Maze fire investigation.

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