# 📐 L2 Spec — Reactor Thermal-Hydraulics — coupled T/H with neutronics Mismatch-Only Spec
**ID:** `L2-359-001` · **Status:** ⊙ Testnet (genesis catalog)
**Parents:** ⬆ Principle [`L1-359`](/artifact/l1/L1-359)
> **🎯 Tolerance (ε):** expression
> **⚖ Difficulty score:** 0.48 · **Delta tier:** 5
> **⛓ On-chain block:** 41554101
---
## 1. Domain Ω
**Type:** `range`
| Parameter | Unit | Range |
|---|---|---|
| Snr db | dB | 0 – 40 |
| N axial | — | 1 – 100 |
| N samples | — | 100 – 100000 |
| N assemblies | — | 1 – 1000 |
| Fuel k error | — | 0.0 – 0.1 |
| Friction factor error | — | 0.0 – 0.2 |
| Boiling correlation error | — | 0.0 – 0.3 |
| Heat transfer coeff error | — | 0.0 – 0.3 |
## 2. Tolerance (ε)
**Type:** `fn`
```
15.0 + 0.25*SNR_dB - 10.0*friction_factor_error - 8.0*boiling_correlation_error - 15.0*fuel_k_error - 6.0*heat_transfer_coeff_error
```
## 3. Difficulty
| Property | Value |
|---|---|
| Difficulty score | 0.48 |
| Delta tier | 5 |
## 4. Fingerprint
`ddc49c5455eb4dcce6540e9defed664a89d8337e39bae20e671848a8d42aadab`
## 5. On-chain Registration
- **Chain hash:** `0x1126c9d9421bbe300c02700cf1b07ca92062169776087709b09723753220e165`
- **Chain tx hash:** `0x154ae0b5dec5077c2b7d60159273028735b4a92591052d2233e0764a28340f91`
- **Chain block:** `41554101`
---
## File Mapping
This bundle consists of: `L2-359-001.md`, `L2-359-001.json`.
| File | Role | How to regenerate |
|------|------|-------------------|
| `L2-359-001.md` | Source of truth — edit this | Human or LLM |
| `L2-359-001.json` | Structured metadata for the registry | LLM regenerates from the sections above |
**Prompt for your LLM after editing this Markdown:**
> Read the attached Markdown. Regenerate the sibling `.json` so every field matches.
> Preserve the schema documented in the rows above.
> Output each file in its own fenced code block tagged with the filename.
> Output only the JSON object.
_This Markdown was auto-synthesized from the catalog row for `L2-359-001`._
_Edit it, regenerate the JSON, and submit at [/submit](/submit) to claim the artifact._