MNJ Machining Ltd. has extensive experience supplying precision CNC-machined components to Tier 1 CANDU contractors from our Toronto facility. Ontario's nuclear industry demands a level of documentation, process discipline, and dimensional precision that few machine shops can consistently deliver — we have built our quality system specifically to meet that standard.
CANDU Liner Tube Components
MNJ specialises in the precision machining of CANDU fuel channel liner tube components. The liner tube sits within the end fitting assembly of each fuel channel, directing heat transport coolant flow and providing the bore through which the fueling machine inserts and removes fuel bundles. It also supports and locates the shield plug, and features a circumferential hole pattern that regulates coolant passage between the end fitting and pressure tube.
Liner tubes are fabricated from Type 410 martensitic stainless steel (ASTM A-268 Grade TP-410) — a material that requires careful management through its heat treatment cycle. Components are rough machined in the annealed condition, aged, then finish machined to final dimensional requirements. Holding the required tolerances on thin-wall geometry in a material that transforms through aging demands both process knowledge and rigorous in-process inspection — capabilities MNJ has developed through years of production experience on these components.
Nuclear Quality & Compliance
Our Quality Management System is compliant with CSA Z299.2, ISO 9001, and AS9100D requirements. All operations are fully customer-auditable through our Operations Portal, with complete visibility into process records, in-process inspection data, non-conformance management, and material traceability. We understand that for nuclear work, the paperwork is as important as the part.
Inspection
All nuclear components are dimensionally verified using our Mitutoyo Crysta Apex CR574 Coordinate Measuring Machine. Full inspection reports and material certifications are provided as standard.
Request a Quote
Send drawings and quality requirements to orders@mnjcnc.com or call (416) 419-1651. We respond within 1–2 business days.