{
  "schema": "c12-htf-functional-state-v2",
  "object": "c12-htf-functions",
  "representation": "Authored conceptual schematic, not a construction detail.",
  "normal_functions": [
    {
      "id": "pump",
      "function": "Maintain circulation and acceptable suction conditions."
    },
    {
      "id": "heater",
      "function": "Add heat subject to minimum circulation/film temperature."
    },
    {
      "id": "consumers",
      "function": "Transfer heat across a process boundary; higher working-pressure ingress is credible."
    },
    {
      "id": "bypass",
      "function": "Preserve circulation at low consumer demand."
    },
    {
      "id": "expansion",
      "function": "Reserve inventory, expansion, degassing/separation; full-flow return through vessel in panel A. Restricted cold-fluid single-leg alternative separately represented in panel B."
    }
  ],
  "maintenance_path": {
    "prerequisites": [
      "Cool fluid as required by the collection arrangement.",
      "Establish the applicable equipment isolation and drain configuration.",
      "Establish vent and receiving capacity."
    ],
    "destination": "Dedicated HTF collection; no connection to unrelated plant drains under this adopted arrangement.",
    "reuse": "Establish fluid suitability before return to common storage or refill.",
    "alternatives": "Buried gravity drain for cooled fluid or evaluated aboveground nitrogen-assisted path; not simultaneously specified."
  },
  "not_shown": [
    "Valve line-ups",
    "Instrumentation/control sequence",
    "Relief sizing",
    "Heater turndown/trim-cooler details",
    "Actual elevations/dimensions",
    "Construction support details",
    "Actual nozzle location; spatial positions are not elevations"
  ],
  "topology_alternatives": [
    {
      "id": "full-flow-alternative",
      "applicability": "Arrangement adopting full flow through expansion vessel.",
      "connections": [
        {
          "from": "consumers",
          "to": "full-flow-vessel",
          "function": "Entire circulating return"
        },
        {
          "from": "consumer-bypass",
          "to": "full-flow-vessel",
          "function": "Maintain heater circulation at reduced consumer demand"
        },
        {
          "from": "full-flow-vessel",
          "to": "pump-suction",
          "function": "Circulating return outlet"
        }
      ],
      "requirement": "Vessel and connecting piping designed for full HTF flow."
    },
    {
      "id": "single-leg-alternative",
      "applicability": "Restricted cold-fluid alternative requiring specific project-authority approval under this basis.",
      "connections": [
        {
          "from": "main-return",
          "to": "pump-suction",
          "function": "Circulating return bypasses vessel"
        },
        {
          "from": "main-return",
          "to": "cold-fluid-vessel",
          "function": "Single-leg expansion connection"
        }
      ],
      "limitation": "Not equivalent to a full-flow degassing path; required expansion/venting/suction/pressure functions need evaluation."
    }
  ],
  "alternatives_not_simultaneous": true
}