Radiation Detection Systems (RDSs) are used to measure and detect abnormal levels of radioactive material in the environment. These systems are used in many applications to mitigate threats posed by high levels of radioactive material. However, these systems lack protection against malicious external attacks to modify the data. The novelty of applying Intrusion Detection Systems (IDS) in RDSs is a crucial element in safeguarding these critical infrastructures. While IDSs are widely used in networking environments to safeguard against various attacks, their application in RDSs is novel. A common attack on RDSs is Denial of Service (DoS), where the attacker aims to overwhelm the system, causing malfunctioning RDSs. This paper proposes an efficient Machine Learning (ML)-based IDS to detect anomalies in radiation data, focusing on DoS attacks. This work explores the use of sampling methods to create a simulated DoS attack based on a real radiation dataset, followed by an evaluation of various ML algorithms, including Random Forest, Support Vector Machine (SVM), logistic regression, and Light Gradient-Boosting Machine (LightGBM), to detect DoS attacks on RDSs. LightGBM is emphasized for its superior accuracy and low computational resource consumption, making it particularly suitable for real-time intrusion detection. Additionally, model optimization and TinyML techniques, including feature selection, parallel execution, and random search methods, are used to improve the efficiency of the proposed IDS. Finally, an optimized and efficient LightGBM-based IDS is developed to achieve accurate intrusion detection for RDSs.

These stark images showing the heart of the Fukushima nuclear disaster zone reveal the devastation inside its destroyed reactor. The scenes were captured by a camera attached to a 50ft rod and inserted into reactor 2 at the doomed Japanese power plant, on the country's north east coast. Footage shows melted nuclear fuel attached to the pillars, walls and ceiling, as well as puddles of coolant, and debris piled up 16 to 27ins thick on the ground. Analysis of the images by the International Research Institute for Nuclear Decommissioning said the spread of debris was suggestive of several holes in the reactor floor. It is seven years since the disaster was unleashed by the Tōhoku earthquake and tsunami. But due to the deadly dose of radiation inside Fukushima, humans have to rely on robots to explore it – and even these have been left malfunctioning and broken.

Tokyo Electric said Thursday that it failed to get any photos of potential fuel debris during a five-day probe of the primary containment vessel at reactor 1 of the Fukushima No. 1 power plant. Tokyo Electric Power Company Holdings Inc., however, stressed that the investigation was worthwhile because its robot was able to take underwater images in the pool of water at its bottom and gauge its radiation level, which will help it estimate where the melted fuel lies. The monstrous tsunami of March 11, 2011, tipped reactors 1, 2 and 3 into core meltdowns. The molten fuel rods then penetrated their pressure vessels before apparently dropping to the bottom of the giant containment vessels. There is about a 2.5-meter deep water pool at the bottom of the primary containment vessel of reactor 1, and Tepco believes most of its melted fuel rods fell into it.

The radiation level in the containment vessel of reactor 2 at the crippled Fukushima No. 1 power plant has reached a maximum of 530 sieverts per hour, the highest since the triple core meltdown in March 2011, Tokyo Electric Power Co. Holdings Inc. said. Tepco said on Thursday that the blazing radiation reading was taken near the entrance to the space just below the pressure vessel, which contains the reactor core. The high figure indicates that some of the melted fuel that escaped the pressure vessel is nearby. At 530 sieverts, a person could die from even brief exposure, highlighting the difficulties ahead as the government and Tepco grope their way toward dismantling all three reactors crippled by the March 2011 disaster. Tepco also announced that, based on its analysis of images taken by a remote-controlled camera, that there is a 2-meter hole in the metal grating under the pressure vessel in the reactor's primary containment vessel.

The radiation level in the containment vessel of reactor 2 at the crippledFukushima No. 1 power plant has reached a maximum of 530 sieverts per hour, the highest since the triple core meltdown in March 2011, oTokyo Electric Power Co. Holdings Inc. said Thursday. The reading means a person could die from even brief exposure, highlighting the difficulties ahead as the government and Tepco grope their way toward dismantling all three reactors that suffered core meltdowns in the March 2011 disaster. Tepco also announced that, based on image analysis, it has discovered a 2-meter hole in the metal grating beneath the pressure vessel inside reactor 2's containment vessel, and discovered a portion of it is warped. The hole could have been caused by melted fuel penetrating the vessel after the March 11, 2011 mega-quake and massive tsunami triggered a station blackout that crippled the plant's ability to keep the reactors cool. The new radiation level, described by some experts as "unimaginable," far exceeds 73 sieverts per hour, the previously highest radiation reading monitored in the interior of the reactor.