Nuclear Fuel Complex
The Nuclear Fuel Complex (NFC), an industrial unit of DAE, was set up at Hyderabad in the early 1970s. NFC is responsible for manufacturing zircaloy clad uranium oxide fuel assemblies and zirconium alloy structural components for all the 14 operating nuclear power reactors (12 PHWRs and 2 BWRs) in India. In addition, NFC produces seamless stainless steel and special alloy tubes and high purity materials for nuclear and non-nuclear applications.
For NFC, the year 2000-2001 was another consecutive
year of success. The annual production targets were met. For natural uranium
oxide fuel for PHWRs, hafnium-free zirconium oxide and special materials
(in particular tantalum-pentoxide powder), the production and sale far
exceeded the targets and all time high production figures were achieved.
On September 9, 2000, NFC crossed a major milestone of manufacturing 2
lakh natural uranium oxide fuel bundles for PHWRs. In December, 2000, NFC
received the ISO-9002 certificate.
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Technology Development & Upgradation
Following technology developments were achieved during the year 2000-2001:
Experiments on combined calcinations & reduction of ammonium diuranate (ADU) were successfully carried out in batches of 6 kg. This would pave the way for reduction in the number of process steps, manpower and material handling for preparation of sinterable grade UO2 powder.
Several cobalt absorber assemblies, flow tube assemblies and other special assemblies were manufactured for NPCIL. In addition, for the first time, stainless steel control blade tubes of size 4.7mm outer diameter and 0.63mm wall thickness were manufactured indigenously for TAPS.
Control & Safety Rod and Sheath subassembly of PFBR were fabricated for the first time for IGCAR. Items like SS porous filters for FBTR control rod subassembly and D9 material for PFBR fuel pin components were indigenously developed as import substitutes. Several perforated clad tubes each with 189 Nos. of 2 mm dia holes were fabricated for FBTR’s Delayed Neutron Detector calibration subassembly.
For the first time Inconel-600 (nickel – chromium – iron) alloy was extruded to 160 mm and 180mm OD and 10 mm wall thickness. Also, 17-7 PH steel was extruded for use in aerospace, nuclear and chemical industries.
Niobium-Titanium super-conductive alloy was extruded from 180mm dia. at slowest speed of extrusion to give maximum possible reduction. This alloy assumes significance as the billet is actually a bundle of hexagonal element consisting of copper and is packed in a 170 mm OD copper tube. For this, more than 500 elements in hexagonal shape had to be deformed during extrusion at uniform rate and at low temperature (590C), without any breakage.
The Tool Room in NFC machined and ground huge flywheels (1450 mm x 215 mm thickness) with precise taper of 1:30 for primary coolant pumps for power reactors. For condition monitoring of pressure tubes in reactors, the Tool Room also manufactured cryogenically treated dies and punch sets with longer life of compaction of chamfered pellets and notches in 5400mm long pressure tube.
For augmenting the batch size of zirconium sponge production and the life of the reduction retort, several modifications were made in the retort design, chloride can and liner. Thus, it was possible to increase the batch size from 550 to 750 kg. Efforts were made to process and dispose off old pyrophoric waste containing free Zr and Mg. A rotary calcinations furnace was commissioned and around 50 MT of waste was incinerated to bring down the free Zr and Mg content within safe limits.
The Special Materials Plant scaled up its production of Tantalum Pentoxide powder from 200 kg. to 500 kg. per month to meet the increased demand for Tantalum Pentoxide from the cutting tool industry and could earn handsome revenue.
New Schemes
The work in the three new schemes namely, 37 Element PHWR Fuel Project for TAPS-III & IV (PHWR 500 Mwe), Replacement and Augmentation of Zirconium Sponge Plant and Advanced Materials Processing and Characterisation Facilities progressed satisfactorily.
Spin-off Products
Manufacturing of special items such as copper blanks for Prithvi Missile for Defence Armament factory and Zircaloy Heating Coils for M/s.Eveready Industries, Mumbai was successfully completed.
Indigenous Equipment Development
NFC designed, built and supplied a high temperature high vacuum heat treatment Furnace to Rare Materials Project, Mysore. The order was bagged by NFC against global competition and there was significant savings in foreign exchange.
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