Radiological characterization of spent control rod assemblies

Lepel, E.A.; Robertson, D.E.; Thomas, C.W.; Pratt, Sharon L.; Haggard, D.L.

doi:10.2172/125115

Cited by 6 publications

(6 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…A variety of 36 Cl analysis methods have been described in the literature, based on ion exchange chromatography [1], silver salts precipitation [1,2] or elimination of iodine by extraction in an ammoniacal solution and silver salts precipitation [3] using a liquid scintillation spectrometer, a gas proportional counter [4] or accelerator mass spectrometry [1,5].…”

Section: Introductionmentioning

confidence: 99%

Radiochemical analysis of chlorine-36

2006

View full text Add to dashboard Cite

The radioactive chlorine isotope, 36 Cl, decays with a half-life of 3×10 5 years by emitting a beta particle (98 %) and by electron capture. The aim of this paper is to propose a radiochemical separation method of 36 Cl from the other beta-gamma emitters present in low and medium radioactive wastes such as spent ion exchange resins and evaporator concentrates, that arise from Nuclear Power Plants and particularly in the wastes that come from decommissioning activities of graphite reactors, in order to provide data for 36 Cl inventory calculations. The separation method proposed is based on an oxidation technique where chlorine is trapped by NaOH. 36 Cl beta emissions are measured by liquid scintillation counting by the dual label technique in order to avoid the contamination produced by 14 C which is also trapped by NaOH and which is the main contaminant present in graphite samples. The sensitivity of this method is sufficient to achieve the needed thresholds for the radiological characterization of the radioactive materials to which this method can be applied.

show abstract

Section: Introductionmentioning

confidence: 99%

Radiochemical analysis of chlorine-36

2006

View full text Add to dashboard Cite

show abstract

“…Lepel et al showed that spent control rods from PWRs can reach up to 1 GBq/g HM 108m Ag and 90 MBq/g HM 110m Ag at the upper part of the control rods with a 108m Ag/ 110m Ag activity ratio of >10. 38 The 108m Ag activity even exceeds the 60 Co activity from steel components in the spent Ag−In−Cd control rods by more than 1 order of magnitude. 38 The significant differences in the 108m Ag/ 110m Ag isotopic ratio are a potentially useful forensic indicator that may provide information about the exact origin of the reactor-derived radiosilver upon its release into the environment.…”

mentioning

confidence: 99%

“…38 The 108m Ag activity even exceeds the 60 Co activity from steel components in the spent Ag−In−Cd control rods by more than 1 order of magnitude. 38 The significant differences in the 108m Ag/ 110m Ag isotopic ratio are a potentially useful forensic indicator that may provide information about the exact origin of the reactor-derived radiosilver upon its release into the environment.…”

mentioning

confidence: 99%

Separation of Ultratraces of Radiosilver from Radiocesium for Environmental Nuclear Forensics

et al. 2020

View full text Add to dashboard Cite

The presence of environmental radiosilver and the investigation of the 108m Ag/ 110m Ag isotopic ratio in the aftermath of a nuclear power plant accident provide valuable information on the condition of the control rods of pressurized water reactors. However, the detection of minute amounts of the γemitting radiosilver isotopes is often thwarted by the presence of concomitant and dominating γ emitters, primarily 137 Cs, which results in increased detection limits in the γ spectra. We developed a rapid and robust separation protocol for trace silver extraction in the presence of overwhelming activities of 137 Cs via the autodepostion of silver on a copper plate. This method achieved a quantitative removal of interfering 137 Cs in the deposition product and proved to be very efficient (yields >70% for aqueous samples), rapid (results within 4 h), and robust with respect to varying salinities and composition of the water samples. The autodeposition approach is also applicable for organic samples after acidassisted microwave digestion. By applying the established sequential extraction protocols for soil, the fate of freshly deposited radiosilver and radiocesium in soil was investigated. Silver showed a high affinity to the soil with a pronounced (>90%) accumulation in the residual fraction after the sequential extraction, whereas radiocesium exhibited higher mobility, allowing for the extraction of major fractions in the first extraction steps. The composition of the aqueous contamination matrix (CaCl 2 or Ca(NO 3 ) 2 ) had a significant influence on the binding properties of cesium on soil.

show abstract

“…Não obstante apresentar atividade pequena em relação à atividade total dos rejeitos radioativos, a determinação precisa de 108m Ag é considerada importante para o gerenciamento adequado desses rejeitos (Lepel et al, 1995;Bihari et al, 2010).…”

Section: Determinação De 108m Agunclassified

“…A diferença entre os resultados obtidos para os reatores BWR e PWR é atribuída ao fato da fonte principal dos radionuclídeos desses pares RDM/RC em reatores PWR ser os tubos do gerador de vapor (Raymond et al, 1995), enquanto em reatores BWR (que não possuem gerador de vapor) o revestimento de aço inoxidável das barras de controle feitas de carbeto de boro (B 4 C) (Lepel et al, 1995) (Silva et al, 2002), durante as quais se observou descamação e pites de corrosão crescentes no revestimento de Ni dessas barras (Silva et al, 2002). Tais descontinuidades no revestimento de Ni causaram a liberação progressiva de isótopos radioativos de Ag das barras de controle para a água de refrigeração, o que foi constatado na época pela detecção de 110m Ag em diversas medidas por espectrometria de raios-gama realizadas na piscina do reator IEA-R1 (Terremoto et al, 2000;Terremoto et al, 2002;Zeituni et al, 2004a;Zeituni et al, 2004b).…”

Section: Comparação Com Concentrações De Atividade Naturaisunclassified

Determinação de fatores de escala para estimativa do inventário de radionuclídeos em rejeitos de média e baixa atividades do reator IEA-R1

Taddei¹

View full text Add to dashboard Cite

Ao colega José Flávio Macacini pela colaboração e disponibilidade durante este projeto, Aos colegas Adriana Calixto de Almeida Lima e Élis de O. Lima Filho pela ajuda na formatação do trabalho, Ao Coordenador do LAPOC/CNEN-MG, Antonio Luiz Quinelato, pela compreensão e colaboração, Aos amigos que estiveram presentes no laboratório e me auxiliaram de alguma maneira neste trabalho, Ao IPEN/CNEN-SP por possibilitar a realização do trabalho.

show abstract

Radiological characterization of spent control rod assemblies

Abstract: Portions of this document may be illegible electronic image products. Images are produced from the best available original document.

Cited by 6 publications

References 3 publications

Radiochemical analysis of chlorine-36

Radiochemical analysis of chlorine-36

Separation of Ultratraces of Radiosilver from Radiocesium for Environmental Nuclear Forensics

Determinação de fatores de escala para estimativa do inventário de radionuclídeos em rejeitos de média e baixa atividades do reator IEA-R1

Contact Info

Product

Resources

About