HWB has successfully set up India’s first medical grade O-18 water production facility at HWP, Manuguru. O-18 water is precursor to F-18 isotope, produced by its proton irradiation in a medical cyclotron, which is then converted to Fluorine-18 de-oxy Glucose i.e. ¹⁸F-FDG. ¹⁸F-FDG is used as tracer for detection of malignant tumors through PET scanning.

1. A vacuum distillation cascade consisting of ten stages is designed for the desired O-18 enrichment with DM water as feed.
2. ≥96% isotopic purity (¹⁸O atom %) H₂¹⁸O generated.

1. The enriched O-18 water is a pre-cursor to F-18 generated by proton irradiation of O-18.
2. F-18, thus produced is then converted to 18-FDG or to Fluorine-18 de-oxy Glucose which is used as a tracer in Positron Emission Tomography (PET) scans for detection and staging of malignancies.

Heavy Water Board has set-up a one of its kind facility, the first in India, for production of O-18 enriched water used in medical cyclotron for production of F-18 isotope required for PET scanning.

Water fractionation under vacuum along with efficient splitting & re-combination unit is developed, deployed and demonstrated for production of H₂¹⁸O of ≥96% O-18 Isotopic Purity (IP) as acceptable for end-use.

A ten-stage water distillation cascade has been designed and implemented at HWP, Manuguru for the purpose. Each cascade stage has surface activated mass transfer packing section, a reflux & trap condenser at top and a re-boiler at bottom to provide liquid reflux at top and vapor load at bottom respectively

All the columns will be operating at 120 mm Hg a. pressure at top. The vacuum will be maintained at top of all the towers with the help of a single vacuum generation unit. Based on the water fractionation in a ten-stage cascade, it is seen that the enrichment of Deuterium is also taking place in addition to O¹⁸ enrichment.

The final product of the water fractionation is being electrolyzed to produce D₂ and ¹⁸O₂. The liberated ¹⁸O₂ shall be re-combined with UHP cylinder Hydrogen and will be stored as H₂¹⁸O product. Instead of using hydrogen cylinder an additional electrolyzer can be installed to generate required ultra-pure hydrogen from natural water for re-combination with O-18. The re-combination is carried out on de-oxo catalyst with H₂ gas as excess reactant. The reactor outlet stream is condensed and excess H₂ is recycled back to the recombination reactor. The condensed H₂¹⁸O is taken out as product of the system.

The Electrolysis along with a re-combiner unit is also called as back-end-unit of the facility.

Final product up-gradation: If the recombination unit product i.e. H₂¹⁸O is required to be re-enriched, due to dilution, ingress of impurities (deuterium) etc., a Product up-gradation unit is provided, consisting of two distillation columns in series.

Final product bottling & storage: The final product i.e. H₂¹⁸O (>96% 18 O atom%) shall be stored in ambient conditions in thoroughly cleaned glass bottles with UHP Nitrogen gas in vapor space.

1. Availability of indigenous O-18 water shall be helpful to society by controlling the cost of PET scanning and thereby cancer treatment cost.
2. Import substitute.
3. Unhindered availability of O-18 water is ensured, even under disturbed geo-political and international disturbances, as import dependency is eliminated.

H₂¹⁸O water (of IP ≥96%) finds application as pre-cursor to F-18 generated by proton irradiation of O-18. F-18 so produced has half-life of around 110 min and is required to be dosed into subject in form of [¹⁸F] Fluoro-deoxy-glucose, a radiopharmaceutical (radiotracer) used in medical imaging, specifically Positron Emission Tomography (PET scans), for detection & staging of malignancies.

SPECIFICATIONS OF THE SYSTEM

Sr. No.	Specification	Value
1	Isotopic Purity, 18 O atom %	≥ 96 %
2	Conductivity, µmhos/cm	< 5
3	pH	6.0 to 8.0
4	Total Organic Carbon, mg/L	≤ 5
5	Fluoride, mg/L	≤ 1
6	Chloride, mg/L	≤ 2
7	Copper, mg/L	≤ 0.1
8	Iron, mg/L	≤ 0.1
9	Magnesium, mg/L	≤ 0.1
10	Sterility test	To be passed

SPACE

1. Based on capacity of plant envisaged, the land requirement will vary. However, for a 10 Kg/yr plant capacity the land requirement is 250 m² (excluding administrative, security and utility area).
2. Similarly, for a 100 Kg/yr plant capacity, the land requirement would be approx. 1025 m² (excluding administrative, security and utility area).

MANPOWER

1. One Engineer can manage overall plant operation with support of one Assistant in General shift.
2. One Assistant along with two technicians are required in round-the-clock.
3. One technician each is envisaged under Mechanical, Electrical and Instrumentation, in general shift for plant maintenance.

POWER SUPPLY

For 100 Kg/yr plant capacity :

1. 2.5 MW electrical load is expected for the facility.
2. 1250 kVA DG unit, for power backup on class-III is required for continuing the operation of distillation cascade for safe shutdown.

Test Equipment

1. Analytical instruments for Deuterium, O-18 and other water chemistry.
2. Mass Spectrometer, EIMS, FTIR, Density meter, etc.

Other facilities

1. The utility packages required for the facility include DM water generation unit, Cooling water unit, chilled water unit, steam generation unit, vacuum generation unit, nitrogen unit, instrument air, product packaging unit etc.