The time has come to replace the 53-year-old Dimona nuclear reactor, according to worried officials.Built in 1963 using technology acquired from France, the lifetime of the reactor – officially known as the Nuclear Research Center–Negev – is 40 years, according the manufacturer’s specifications.Several members of Knesset are calling for an emergency meeting to be held to discuss the reactor’s safety and replacement. Recently, an ultrasound scan of the reactor’s core, made of metal covered in concrete, revealed 1,537 defects.In 2004, the issue of obsolescence was discussed at a symposium in Beersheba at Ben-Gurion University of the Negev, where officials of the Israel Atomic Energy Commission – which is responsible for the reactor in Dimona – admitted that they were encountering difficulties in upgrading the reactor’s security.On Wednesday, former Dimona mayor and current Yesh Atid MK Meir Cohen said that an emergency session of the Knesset’s Health Committee will meet as soon as the Knesset returns from its Passover recess.Speaking on 103 FM Radio, Cohen said that he had a discussion with “the head of the NRCN [Nuclear Research Center–Negev],” who is Ehud Netzer. Cohen was told by him that “the reactor is secure.”Netzer reportedly told Cohen that the NRCN was “looking into the matters and have the means to look into it,” but Cohen said the response was not enough.He said the findings are worrying and require an in-depth investigation. “It’s no longer possible to hide behind a veil of secrecy and security,” he said.“The problem is that all nuclear reactors of this type were shut down after 40 years and the reactor in Dimona has been working since 1963,” he said.“The head of the NRCN told me he will come to every Knesset committee and reveal everything,” Cohen said, adding that he expects members of the Atomic Energy Commission and NRCN to be present at the Knesset meetings and “lay everything out on the table.”Meretz MK Michal Rozin was among the voices calling for an emergency session on the issue. In an official letter to Likud MK Tzachi Hanegbi, who chairs the Knesset’s Foreign Affairs and Defense Committee, she criticized the fact that the reactor is not subject to outside inspection, neither foreign nor domestic.“The nuclear reactor is not under any sort of inspection aside from the body that runs it, the Israel Atomic Energy Commission,” she wrote.She also noted that in 64 years that the Atomic Energy Commission has been in existence, the nuclear reactor’s activities have not been legally laid out nor has there been any sort of public body to check it.A 1980 law regarding radioactive materials, she said, states that the Atomic Energy Commission is not subject to its guidelines.“If the current state of affairs continues,” she wrote, “it endangers the IAEC’s work, its workers’ health, the environment, the health and well-being of Israeli citizens and national security.”Zionist Union MK Yael Cohen-Paran called the situation worrying, saying that it raises “difficult questions about the NRCN’s management.”She said that she intends to request data about the reactor from Prime Minister Benjamin Netanyahu and the Atomic Energy Commission Hadash MK Dov Henin criticized what he called a national policy of staying mum on any nuclear issue.He said that the reactor should have been replaced long ago, and demanded that an external, expert body inspect the reactor and present a report to the Knesset.In January 2012, media reports indicated that the Atomic Energy Commission had decided to, at least temporarily, shut down the reactor. The site’s vulnerability to attack from Iran was cited as the main reason for the decision.In October and November 2012, it was reported that Hamas had fired rockets at Dimona and/or the NRCN.In July 2014, Hamas again fired rockets toward the area surrounding the reactor. The aging facility was not harmed or damaged in any of the attempted strikes.Yossi Melman contributed to this report.