The second paper, by Benyo et al., touches on the apparent inducement of radioactivity in deuterated materials. The paper is an April 2017 report with a lot of researchers directly or indirectly associated with NASA Glenn Research Center that reports preliminary findings. The authors observed beta activity arising both in deuterated polyethylene (PDE) targets and in targets that combine DPE with titanium deuteride, as well as alpha activity in combined samples only (I think). There were several kinds of controls, and the controls showed no activity above the minimum detectable amount (MDA), in contrast to the samples that showed activity, which was in some cases well above the minimum detectable amount. The alpha activity died down quickly, and the beta activity in several samples persisted over a 12 month period.
The authors conclude:
Quote
Fourteen tests out of 19 total runs in this test sequence with either DPE or DPE with TiD2 were beta activated. Some samples exhibited alphas, which decayed below MDA in approximately an hour following x-ray exposure. Several of the samples with DPE and TiD2 showed persistent beta activity. Several of the samples (SL10A, SL16, and SL17A) showed beta activity above background with a greater than 4σ confidence level for months after exposure. Portions of SL10A, SL16, and SL17A were scanned using a beta scintillator and found to have beta counts in the tritium energy band, continuing without noticeable decay for over 12 months. Beta scintillation investigation of as-received materials (before xray exposure) showed no beta counts in the tritium energy band, indicating the beta emitters were not in the starting materials.
By "tritium energy band," they're referring to a very general categorization of beta energy levels performed by one of their scintillator detectors into three energy bands, one for tritium, one for carbon-14 and one for phosphorus-32. So the beta emitter might or might not be tritium proper.
The method used in this paper is notably different from that of the first paper, in that x-rays in the range 65 – 280 keV were used, in contrast to the ~ 2 MeV photons that were used in the first paper. The energy of a tritium decay is ~ 19 keV, so the relative energy of these photons is significant. However, there is no way that I know of recognized by physics to induce long-lived beta or alpha activity using x-ray photons. The findings of this paper seem to be important if confirmed.