Designing a system to detect leaking in fuel elements in Brazilian Triga research reactor

Rodrigues, Rogerio Rivail; Mesquita, Amir Zacarías; Palma, Daniel Artur Pinheiro

doi:10.1504/ijnest.2018.10016742

Cited by 2 publications

(6 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The increase in ionic impurities levels adversely influences the following aspects: corrosion of materials in the reactor cooling system, increase in the radiation field and fuel performance. Therefore, pH needs to be close to neutrality while electrical conductivity should be kept as low as possible [2]. Emphasizing that, nowadays, there is no system that monitors these parameters in real time (on-line approach) in CDTN IPR-R1 research reactor as suggested by IAEA [4].…”

Section: Expected Results and Discussionmentioning

confidence: 99%

“…In the aforementioned subproject, a mandatory experiment was included in such research reactor, that is, the performance of tests to verify possible fission product leaks in its fuel elements [2]. Due to Covid pandemic and homework activities, this experiment has not yet been performed, but it is intended to be realized as soon as Triga reactor returns to regular operation.…”

Section: Introductionmentioning

confidence: 99%

“…In the specific case of Triga reactor, most of its fuel elements are in the core where corrosion can occur, what can compromise its fuel coating integrity. Its cooling water must be treated and controlled to maintain low levels of electrical conductivity and pH close to neutrality, in order to minimize potential corrosion processes, particularly in fuel elements [2]. At some point in the future, like other reactors, IPR-R1 will be permanently shut down.…”

Section: Introductionmentioning

confidence: 99%

“…• Perform gamma spectrometry experiments for IPR-R1 well water to check possible fission products leakage in the fuel elements of Triga reactor (sipping test) [2].…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Methodology for Management and Physicochemical Control of the Cooling Water of the IPR-R1 Triga Nuclear Research Reactor

Marques

Mesquita²,

Costa³

et al. 2022

Braz. J. Rad. Sci.

View full text Add to dashboard Cite

The IPR-R1 Triga research reactor, located at CDTN (Nuclear Technology Development Center) in Brazil, is one of the oldest reactors in operation worldwide. The Brazilian Nuclear Energy Commission (Cnen) has granted a Permit for Permanent Operation license for the CDTN Triga reactor. This authorization includes some conditions to be settled within a period of up to two years, that is, until the end of 2019, which has not yet been carried out and is currently being prepared by CDTN. For this purpose, Project 0006.23 – Maintenance of Licensing of the IPR-R1 Triga Reactor was created in CDTN's Multiannual Program. In this project is included the Subproject: 6.23.3 – Preparation of the system to manage the aging of the IPR-R1 Triga reactor. Inserted in this context, the main objective of this paper is the proposal of good practices to be adopted in the future by CDTN, related to the Projects of Licensing and Aging of Triga reactor, for the management and physicochemical control of its cooling water, considering its electrical conductivity and pH, following IAEA recommendations. So, the present work is relevant, as it addresses a proposal for monitoring and controlling pH and electrical conductivity of the cooling water of Triga reactor. As a result of this proposal, the useful life of Triga reactor may be extended and there will be greater reliability and safety in its operation.

show abstract

Section: Expected Results and Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

“…• Perform gamma spectrometry experiments for IPR-R1 well water to check possible fission products leakage in the fuel elements of Triga reactor (sipping test) [2].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Methodology for Management and Physicochemical Control of the Cooling Water of the IPR-R1 Triga Nuclear Research Reactor

Marques

Mesquita²,

Costa³

et al. 2022

Braz. J. Rad. Sci.

View full text Add to dashboard Cite

show abstract

“…Several evidence of the occurrence of this kind of event are found in literature since the 1970s, and many techniques have been developed to solve this issue, i.e. identifying the fuel element(s) responsible of the release of fission products, with the following removal from the reactor core [1][2][3][4][5]. Identification of a cladding defect could be monitored by gamma spectrometry characterization of water samples taken from the primary water loop of the reactor, or by monitoring the ionic-exchange resins installed for primary water purification.…”

Section: Introductionmentioning

confidence: 99%

Defected fuel rods identification in TRIGA Reactors: The experience at the ENEA Casaccia TRIGA RC-1 reactor

Lepore,

Falconi,

Fabrizio

et al. 2023

EPJ Web Conf.

View full text Add to dashboard Cite

Experience in running TRIGA reactors all around the world has shown that fuel cladding failures can occur. Fission products, especially in gaseous physical form, can exit the defected fuel rods being dispersed within the water primary coolant. Suspects of a cladding failure event can be confirmed by detection of short-lived fission products, i.e., Krypton, Xenon, and even Iodine isotopes in primary water, or within the ionic-exchange resins tank installed for the purification of the primary coolant loop. The magnitude of the release of those ‘key-indicators’ from the defected fuel element(s) is the driving method by which the defected rod(s) can be identified. ‘Significant’ releases can be detected with a direct online sampling of the water from the top of the suspected fuel rod with reactor at power, leading this water to an online high-resolution gamma spectrometry analysis system. By considering delays due to the water velocity in tubes and decay time of radionuclides identified within the gamma spectrum, it is possible to calculate the concentration of those radionuclides just emerging from the inspected fuel rod. Releases lower than the minimum detection capabilities of the previous online experimental configuration push to modify the detection method with an indirect identification of the release. This is the case when the ‘normal’ radioactive background of the activated water, when reactor is on power, is the dominant component in the gamma spectrum of the sampled water, and fission gases (even produced) are not identified promptly, i.e. a relationship to a specific fuel rod by the sampling circuit before could not be identified. The paper describes the experience carried out at the Italian ENEA TRIGA RC-1 reactor, deepening the technical aspects and solutions applied to solve the issue. In particular, a ‘significant’ release has been found in the instrumented fuel rod within ring B, i.e. the inner fuel ring, exposed to the maximum neutron flux of the reactor. The leaking element was found within a week, in two days of operation, being the sampling system designed on detection of minutes-shortlived fission gases (no need to ‘cool’ down the primary loop by waiting decay of hours-lived radionuclides). After the removal of the instrumented fuel rod in ring B, further days in searching other ‘significant’ release with the sampling circuit before have reported nothing detected. But in samples of water taken after reactor shutdown, some iodine emerged after decaying of ‘normal’ radioactive background of the activated water. This was sufficient evidence of another defected fuel rod in the pool. Identification of the latter defected fuel element is still ongoing, being based on: 1) selective removal of rod(s) from the reactor core, 2) run power of the reactor, 3) take samples of water after shutdown and measure iodine after decaying of ‘normal’ radioactive-background of the activated water, 4) identify the rod responsible of the remaining leakage when no further iodine is detected.

show abstract

Designing a system to detect leaking in fuel elements in Brazilian Triga research reactor

Cited by 2 publications

References 0 publications

Methodology for Management and Physicochemical Control of the Cooling Water of the IPR-R1 Triga Nuclear Research Reactor

Methodology for Management and Physicochemical Control of the Cooling Water of the IPR-R1 Triga Nuclear Research Reactor

Defected fuel rods identification in TRIGA Reactors: The experience at the ENEA Casaccia TRIGA RC-1 reactor

Contact Info

Product

Resources

About