{
  "ftaDoc": {
    "version": "5.0",
    "standard": "IEC61025",
    "savedAt": "2026-03-10T03:38:07.486688Z"
  },
  "projects": [
    {
      "id": "p19e4f8a4",
      "name": "Nuclear \u2014 Reactor Protection",
      "expanded": true,
      "settings": {
        "description": "Fault tree analysis for failure of reactor emergency shutdown (SCRAM) system. Covers control rod insertion failure, reactor protection system logic failure, and ECCS failure. Developed per MIL-STD-882E, IEEE Std 603, and 10 CFR 50 Appendix A. Target probability: <1E-5 per demand (single failure criterion per GDC 17).",
        "organization": "FTA Studio Template Library",
        "analyst": "",
        "revision": "A",
        "standard": "IEC61025",
        "silTarget": "",
        "missionTime": 8760,
        "anaMethod": "exact",
        "sciNotation": true
      },
      "ftas": [
        {
          "id": "ff9fabe34",
          "name": "Reactor Fails to SCRAM",
          "nodes": [
            {
              "id": "n4258b57c",
              "uid": "TOP-001",
              "ntype": "top",
              "gateType": "AND",
              "name": "Reactor Fails to SCRAM (Emergency Shutdown)",
              "desc": "Reactor does not achieve prompt subcritical shutdown on demand following initiating event. Ref: MIL-STD-882E, IEEE Std 603, 10 CFR 50 App A. Target: <1\u00d710\u207b\u2075 per demand.",
              "outputId": null,
              "refId": null,
              "prob": null,
              "lambda": null,
              "mu": null,
              "missionTime": 8760,
              "sil": null,
              "failureMode": "",
              "detection": "",
              "hazards": [],
              "evidence": "",
              "mitigation": "",
              "severity": null,
              "occurrence": null,
              "detectability": null,
              "x": 580.0,
              "y": 80
            },
            {
              "id": "n07a5198e",
              "uid": "G-001",
              "ntype": "gate",
              "gateType": "OR",
              "name": "Control Rod Insertion Failure",
              "desc": "One or more control rods fail to reach fully inserted position.",
              "outputId": "n4258b57c",
              "refId": null,
              "prob": null,
              "lambda": null,
              "mu": null,
              "missionTime": 8760,
              "sil": null,
              "failureMode": "",
              "detection": "",
              "hazards": [],
              "evidence": "",
              "mitigation": "",
              "severity": null,
              "occurrence": null,
              "detectability": null,
              "x": -60.0,
              "y": 250
            },
            {
              "id": "n263bf7be",
              "uid": "G-002",
              "ntype": "gate",
              "gateType": "OR",
              "name": "Mechanical Rod Drive Failure",
              "desc": "Physical obstruction or mechanical failure preventing rod insertion.",
              "outputId": "n07a5198e",
              "refId": null,
              "prob": null,
              "lambda": null,
              "mu": null,
              "missionTime": 8760,
              "sil": null,
              "failureMode": "",
              "detection": "",
              "hazards": [],
              "evidence": "",
              "mitigation": "",
              "severity": null,
              "occurrence": null,
              "detectability": null,
              "x": -220.0,
              "y": 420
            },
            {
              "id": "n40616279",
              "uid": "BE-001",
              "ntype": "basic",
              "gateType": null,
              "name": "Control rod drive mechanism mechanical jam",
              "desc": "CRDM mechanical failure \u2014 worn/damaged coupling or guide tube debris preventing free fall.",
              "outputId": "n263bf7be",
              "refId": null,
              "prob": null,
              "lambda": 5e-07,
              "mu": null,
              "missionTime": 8760,
              "sil": null,
              "failureMode": "Rod stuck \u2014 partial or no insertion",
              "detection": "Rod position indication; insertion time monitoring",
              "hazards": [],
              "evidence": "",
              "mitigation": "Periodic SCRAM time testing; CRDM maintenance programme",
              "severity": null,
              "occurrence": null,
              "detectability": null,
              "x": -300.0,
              "y": 590
            },
            {
              "id": "na7480585",
              "uid": "BE-002",
              "ntype": "basic",
              "gateType": null,
              "name": "Guide tube obstruction \u2014 debris",
              "desc": "Foreign material in reactor vessel guide tube impeding control rod travel.",
              "outputId": "n263bf7be",
              "refId": null,
              "prob": null,
              "lambda": 2e-07,
              "mu": null,
              "missionTime": 8760,
              "sil": null,
              "failureMode": "Rod insertion blocked",
              "detection": "Rod position indicator; flow monitoring",
              "hazards": [],
              "evidence": "",
              "mitigation": "Coolant filtration; periodic flush; pre-startup rod drop test",
              "severity": null,
              "occurrence": null,
              "detectability": null,
              "x": -140.0,
              "y": 590
            },
            {
              "id": "n3a051016",
              "uid": "G-003",
              "ntype": "gate",
              "gateType": "AND",
              "name": "Electromagnetic Latch Release Failure",
              "desc": "Both the de-energisation AND the power isolation must fail.",
              "outputId": "n07a5198e",
              "refId": null,
              "prob": null,
              "lambda": null,
              "mu": null,
              "missionTime": 8760,
              "sil": null,
              "failureMode": "",
              "detection": "",
              "hazards": [],
              "evidence": "",
              "mitigation": "",
              "severity": null,
              "occurrence": null,
              "detectability": null,
              "x": 100.0,
              "y": 420
            },
            {
              "id": "n1f351f78",
              "uid": "BE-003",
              "ntype": "basic",
              "gateType": null,
              "name": "CRDM electromagnet fails to de-energise",
              "desc": "CRDM hold coil fails to release on SCRAM signal \u2014 stuck relay or shorted coil.",
              "outputId": "n3a051016",
              "refId": null,
              "prob": null,
              "lambda": 1e-07,
              "mu": null,
              "missionTime": 8760,
              "sil": null,
              "failureMode": "Rod held by residual magnetism",
              "detection": "Current monitoring on CRDM coils",
              "hazards": [],
              "evidence": "",
              "mitigation": "Redundant trip coil circuits; fail-safe de-energise design",
              "severity": null,
              "occurrence": null,
              "detectability": null,
              "x": 20.0,
              "y": 590
            },
            {
              "id": "nebad76ce",
              "uid": "BE-004",
              "ntype": "basic",
              "gateType": null,
              "name": "CRDM power supply not isolated on SCRAM",
              "desc": "SCRAM breaker fails to open \u2014 preventing power isolation from hold coils.",
              "outputId": "n3a051016",
              "refId": null,
              "prob": null,
              "lambda": 5e-08,
              "mu": null,
              "missionTime": 8760,
              "sil": null,
              "failureMode": "Power maintained \u2014 rod not released",
              "detection": "Switchgear position monitoring",
              "hazards": [],
              "evidence": "",
              "mitigation": "Independent SCRAM breaker; Class 1E separation",
              "severity": null,
              "occurrence": null,
              "detectability": null,
              "x": 180.0,
              "y": 590
            },
            {
              "id": "n32b570bd",
              "uid": "G-004",
              "ntype": "gate",
              "gateType": "AND",
              "name": "Reactor Protection System Failure",
              "desc": "RPS fails to generate valid SCRAM signal.",
              "outputId": "n4258b57c",
              "refId": null,
              "prob": null,
              "lambda": null,
              "mu": null,
              "missionTime": 8760,
              "sil": null,
              "failureMode": "",
              "detection": "",
              "hazards": [],
              "evidence": "",
              "mitigation": "",
              "severity": null,
              "occurrence": null,
              "detectability": null,
              "x": 700.0,
              "y": 250
            },
            {
              "id": "n8ab2fce9",
              "uid": "G-005",
              "ntype": "gate",
              "gateType": "VOTE",
              "name": "Neutron Flux High-High Signal (2oo3 Fails)",
              "desc": "All three neutron flux channels must fail to trip for 2oo3 voting to fail.",
              "outputId": "n32b570bd",
              "refId": null,
              "prob": null,
              "lambda": null,
              "mu": null,
              "missionTime": 8760,
              "sil": null,
              "failureMode": "",
              "detection": "",
              "hazards": [],
              "evidence": "",
              "mitigation": "",
              "severity": null,
              "occurrence": null,
              "detectability": null,
              "x": 500.0,
              "y": 420,
              "voteK": 2,
              "voteN": 3
            },
            {
              "id": "n823434e1",
              "uid": "BE-005",
              "ntype": "basic",
              "gateType": null,
              "name": "Neutron flux detector channel 1 fails high",
              "desc": "Fission chamber or ion chamber in Channel 1 fails to indicate high flux.",
              "outputId": "n8ab2fce9",
              "refId": null,
              "prob": null,
              "lambda": 2e-07,
              "mu": null,
              "missionTime": 8760,
              "sil": null,
              "failureMode": "Channel does not trip",
              "detection": "Channel bypass indication; periodic surveillance test",
              "hazards": [],
              "evidence": "",
              "mitigation": "Channel 1 independently powered and cabled (Class 1E)",
              "severity": null,
              "occurrence": null,
              "detectability": null,
              "x": 340.0,
              "y": 590
            },
            {
              "id": "nfde181f1",
              "uid": "BE-006",
              "ntype": "basic",
              "gateType": null,
              "name": "Neutron flux detector channel 2 fails high",
              "desc": "Fission chamber or ion chamber in Channel 2 fails to indicate high flux.",
              "outputId": "n8ab2fce9",
              "refId": null,
              "prob": null,
              "lambda": 2e-07,
              "mu": null,
              "missionTime": 8760,
              "sil": null,
              "failureMode": "Channel does not trip",
              "detection": "Channel bypass indication; periodic surveillance test",
              "hazards": [],
              "evidence": "",
              "mitigation": "Physical separation from Channel 1; different manufacturer",
              "severity": null,
              "occurrence": null,
              "detectability": null,
              "x": 500.0,
              "y": 590
            },
            {
              "id": "n5b05231f",
              "uid": "BE-007",
              "ntype": "basic",
              "gateType": null,
              "name": "Neutron flux detector channel 3 fails high",
              "desc": "Fission chamber or ion chamber in Channel 3 fails to indicate high flux.",
              "outputId": "n8ab2fce9",
              "refId": null,
              "prob": null,
              "lambda": 2e-07,
              "mu": null,
              "missionTime": 8760,
              "sil": null,
              "failureMode": "Channel does not trip",
              "detection": "Channel bypass indication; periodic surveillance test",
              "hazards": [],
              "evidence": "",
              "mitigation": "Physical separation from Channels 1 and 2",
              "severity": null,
              "occurrence": null,
              "detectability": null,
              "x": 660.0,
              "y": 590
            },
            {
              "id": "n724536b1",
              "uid": "G-006",
              "ntype": "gate",
              "gateType": "AND",
              "name": "RPS Logic System Failure",
              "desc": "Both primary and backup RPS logic must fail.",
              "outputId": "n32b570bd",
              "refId": null,
              "prob": null,
              "lambda": null,
              "mu": null,
              "missionTime": 8760,
              "sil": null,
              "failureMode": "",
              "detection": "",
              "hazards": [],
              "evidence": "",
              "mitigation": "",
              "severity": null,
              "occurrence": null,
              "detectability": null,
              "x": 900.0,
              "y": 420
            },
            {
              "id": "n86b9b71d",
              "uid": "BE-008",
              "ntype": "basic",
              "gateType": null,
              "name": "Primary RPS logic controller fault",
              "desc": "Primary RPS digital or relay logic system \u2014 hardware failure preventing SCRAM signal.",
              "outputId": "n724536b1",
              "refId": null,
              "prob": null,
              "lambda": 1e-07,
              "mu": null,
              "missionTime": 8760,
              "sil": null,
              "failureMode": "No SCRAM signal generated",
              "detection": "Continuous online testing; diagnostics",
              "hazards": [],
              "evidence": "",
              "mitigation": "Qualified Class 1E design; qualification testing per IEEE Std 603",
              "severity": null,
              "occurrence": null,
              "detectability": null,
              "x": 820.0,
              "y": 590
            },
            {
              "id": "na8c78ce0",
              "uid": "BE-009",
              "ntype": "basic",
              "gateType": null,
              "name": "Backup (diverse) RPS logic failure",
              "desc": "Diverse backup RPS \u2014 different technology to primary, guards against common-cause.",
              "outputId": "n724536b1",
              "refId": null,
              "prob": null,
              "lambda": 1e-07,
              "mu": null,
              "missionTime": 8760,
              "sil": null,
              "failureMode": "No backup SCRAM signal",
              "detection": "Independent surveillance test schedule",
              "hazards": [],
              "evidence": "",
              "mitigation": "Diverse technology from primary RPS (diversity to prevent CCF)",
              "severity": null,
              "occurrence": null,
              "detectability": null,
              "x": 980.0,
              "y": 590
            },
            {
              "id": "na01b998c",
              "uid": "G-007",
              "ntype": "gate",
              "gateType": "OR",
              "name": "Emergency Core Cooling System Failure",
              "desc": "ECCS fails to deliver sufficient coolant to prevent core damage after shutdown.",
              "outputId": "n4258b57c",
              "refId": null,
              "prob": null,
              "lambda": null,
              "mu": null,
              "missionTime": 8760,
              "sil": null,
              "failureMode": "",
              "detection": "",
              "hazards": [],
              "evidence": "",
              "mitigation": "",
              "severity": null,
              "occurrence": null,
              "detectability": null,
              "x": 1220.0,
              "y": 250
            },
            {
              "id": "n1d3e8526",
              "uid": "BE-010",
              "ntype": "basic",
              "gateType": null,
              "name": "High-pressure ECCS injection pump failure",
              "desc": "ECCS high-pressure injection pump fails to start or deliver flow on demand.",
              "outputId": "na01b998c",
              "refId": null,
              "prob": null,
              "lambda": 3e-07,
              "mu": null,
              "missionTime": 8760,
              "sil": null,
              "failureMode": "No coolant injection",
              "detection": "Pump flow and pressure monitoring; periodic test",
              "hazards": [],
              "evidence": "",
              "mitigation": "Multiple trains of ECCS (minimum 2 independent trains)",
              "severity": null,
              "occurrence": null,
              "detectability": null,
              "x": 1140.0,
              "y": 420
            },
            {
              "id": "n72ef2722",
              "uid": "BE-011",
              "ntype": "basic",
              "gateType": null,
              "name": "ECCS injection valve fails to open",
              "desc": "Motor-operated or check valve in ECCS injection line fails to open on demand.",
              "outputId": "na01b998c",
              "refId": null,
              "prob": null,
              "lambda": 2e-07,
              "mu": null,
              "missionTime": 8760,
              "sil": null,
              "failureMode": "Coolant path blocked",
              "detection": "Valve position monitoring; periodic stroke test",
              "hazards": [],
              "evidence": "",
              "mitigation": "Air-to-open (fail-open) design where practicable; redundant valve trains",
              "severity": null,
              "occurrence": null,
              "detectability": null,
              "x": 1300.0,
              "y": 420
            }
          ],
          "cam": {
            "x": 360,
            "y": 40,
            "zoom": 0.72
          },
          "analysis": null,
          "ccfGroups": [],
          "disjointGroups": [],
          "diagramPages": [],
          "seqId": 1
        }
      ],
      "eventLibrary": []
    }
  ],
  "_id": 200,
  "_uid": {},
  "ccfGroups": []
}