Translations for irreparable in French

Here are paragraphs from public domain books translated:
"The unsatisfactory appearance of it is due to the fact," said he, "that on descending the river the boat was upset and the case which contained the undeveloped films was broken, with disastrous results. Nearly all of them were totally ruined—an irreparable loss. This is one of the few which partially escaped. This explanation of deficiencies or abnormalities you will kindly accept. There was talk of faking. I am not in a mood to argue such a point." — L’aspect défectueux de cette épreuve tient à ce qu’en descendant la rivière, notre bateau chavira, et la caisse contenant les films non développés se brisa. La plupart des films furent gâtés. Je subis de ce fait une perte irréparable, presque un désastre. Cependant, je sauvai partiellement quelques photographies, celle-ci entre autres ; et vous voudrez bien accepter cette explication de l’état dans lequel je vous la présente. On a parlé de maquillage : je ne me sens pas en humeur de discuter une pareille allégation.
The Lost World, by Arthur Conan Doyle Le Monde perdu, de Arthur Conan Doyle
"When quiet had been restored and the audience resumed their seats after the ovation which they had given to the travellers, the chairman, the Duke of Durham, addressed the meeting. 'He would not,' he said, 'stand for more than a moment between that vast assembly and the treat which lay before them. It was not for him to anticipate what Professor Summerlee, who was the spokesman of the committee, had to say to them, but it was common rumour that their expedition had been crowned by extraordinary success.' (Applause.) 'Apparently the age of romance was not dead, and there was common ground upon which the wildest imaginings of the novelist could meet the actual scientific investigations of the searcher for truth. He would only add, before he sat down, that he rejoiced—and all of them would rejoice—that these gentlemen had returned safe and sound from their difficult and dangerous task, for it cannot be denied that any disaster to such an expedition would have inflicted a well-nigh irreparable loss to the cause of Zoological science.' (Great applause, in which Professor Challenger was observed to join.) « Quand, le calme rétabli et l’ovation terminée, les assistants eurent repris leurs sièges, le président, duc de Durham, prononça quelques paroles. Il ne voulait pas faire attendre plus d’une minute à l’assemblée le plaisir que lui promettait cette séance. Il n’avait pas à préjuger ce qu’allait dire, au nom du comité, le professeur Summerlee ; mais déjà la rumeur courante affirmait l’extraordinaire succès de l’expédition. (Applaudissements.) Apparemment, les temps de romanesque n’étaient pas révolus ; il y avait un terrain sur lequel pouvaient se rencontrer les plus extravagantes imaginations du romancier et les découvertes du chercheur en quête de vérité scientifique. L’orateur se réjouissait avec toute l’assistance de voir ces messieurs revenus sains et saufs, ayant accompli leur difficile et dangereuse tâche, car le désastre de l’expédition eût sans contredit infligé une perte irréparable à la cause de la science zoologique. ( Applaudissements, auxquels s’associa ostensiblement le professeur Challenger).
The Lost World, by Arthur Conan Doyle Le Monde perdu, de Arthur Conan Doyle