Derek Cappon

During the life of a nuclear reactor, there are changes to the in-core components that are a function of operating environment and time. It is important to know how the properties of critical core components change, which can be assessed through materials surveillance programs. It is also desirable to characterize materials behaviour long before the end of the reactor design life. Therefore, experiments to characterize materials for in-core applications are performed in test reactors that typically have higher total neutron fluxes than power reactors. The extensive in-core materials irradiation programs that supported the validation of long-term material behaviour in CANDU (CANada Deuterium Uranium) reactors used various irradiation facilities, both domestic and international, are summarized in this paper. However, these test reactor facilities are aging and in some cases are closing, including NRU, which ceased operations in 2018. As Canada contemplates a new domestic high-flux test reactor to support both existing and potential new power reactors, this paper provides a review of the facilities and approaches that were implemented to successfully research CANDU reactor materials and can serve as a basis to define future facility requirements.

Importance: ¹⁷⁷Lu therapy as part of theranostic treatment for cancer is expanding but it can be a challenge for sites with limited radiation protection staff to implement the radiation safety program required for therapeutic nuclear medicine. Objective: To increase the adoption of ¹⁷⁷Lu therapy, especially in smaller centers and clinics, by providing a collection of radiation safety best practices and operational experience. To provide a resource for radiation safety officers supporting the implementation of a ¹⁷⁷Lu therapy program. Methods: A panel of 11 radiation safety professionals representing sites across Canada and the United States with experience delivering ¹⁷⁷Lu therapy was assembled and discussed their responses to a list of questions focused on the following radiation safety topics: facility layout and design; radiation safety program; and drug management and patient care. Results: A comprehensive set of best practice guidelines for clinical radiation safety during ¹⁷⁷Lu therapy has been developed based on the collective operational experience of a group of radiation safety professionals. Significant findings included that ¹⁷⁷Lu therapy is often safely administered in unshielded rooms, that staff radiation exposure associated with ¹⁷⁷Lu therapy is minimal relative to other nuclear medicine programs, and that some relatively simple preparation in advance including papering of common surfaces and planning for incontinence can effectively control contamination during therapy. Conclusion: The guidance contained in this paper will assist radiation safety professionals in the implementation of safe, effective ¹⁷⁷Lu therapy programs, even at smaller sites with limited to no experience in therapeutic nuclear medicine.

Time-resolved fluorescence (TRF) and diffuse reflectance (DR) spectroscopy are two optical biopsy modalities that have been studied in tumor diagnosis. Combination of TRF and DR spectroscopy allows us to obtain more features such as fluorescence intensity, lifetime, and optical properties; thus, potentially improving the tissue diagnostic accuracy. In this paper, an integrated TRF-DR spectroscopy instrument was developed to acquire TRF spectra as well as spatially resolved diffuse reflectance spectra in sequence for intraoperative detection of brain tumor margin. The performance of TRF-DR spectroscopy instrumentation was calibrated and evaluated using endogenous biomolecules, tissue phantoms, and ex vivo brain tumor specimens. The results demonstrated that the TRF-DR system is capable to retrieve the fluorescence and optical properties accurately.