|Year : 2010 | Volume
| Issue : 4 | Page : 192-194
Dose mapping of FIPLY food irradiator
Shashikala Ojha1, Satya Manoj Bairwa1, SK Suman1, AK Ram2, RK Yadav2, S Murali1
1 Radiation Safety Systems Division, BARC, Mumbai, India
2 Food Technology Division, BARC, Mumbai, India
|Date of Web Publication||1-Dec-2011|
Radiation Safety Systems Division, BARC, Mumbai
Source of Support: None, Conflict of Interest: None
The 60 Co source is used in the FIPLY irradiator. The source is stored under water and the water pool acts as the shield and is useful for the removal of the decay heat. The radiation field measurement on the water pool area was desired to be carried out for different depths of water and during the source held in the exposed state, gamma dose mapping in the irradiator room with distance from the source rack. The paper describes the radiation field prevailing at various depths of water pool with source under water and gamma dose with distance in the irradiator room during the sources held in the exposed state.
Keywords: Food irradiator, gamma dose mapping, 60 Co source
|How to cite this article:|
Ojha S, Bairwa SM, Suman S K, Ram A K, Yadav R K, Murali S. Dose mapping of FIPLY food irradiator. Radiat Prot Environ 2010;33:192-4
|How to cite this URL:|
Ojha S, Bairwa SM, Suman S K, Ram A K, Yadav R K, Murali S. Dose mapping of FIPLY food irradiator. Radiat Prot Environ [serial online] 2010 [cited 2021 Aug 4];33:192-4. Available from: https://www.rpe.org.in/text.asp?2010/33/4/192/90464
| 1. Introduction|| |
Food materials are gamma irradiated for select doses for disinfestations and increasing the shelf life of the products. The FIPLY irradiator is used for the purpose needed the gamma dose mapping for the two sources-held under water and in exposed conditions radiation field vis-à-vis the distance in the irradiator room. The experiments were conducted on different occasions and for different source conditions. The gamma dose mapping results are useful for planning the time period of irradiation for food materials, since presently films/dosimeters are used for the verification of irradiation dose.
1.1 Food irradiator
Irradiation is carried out inside an irradiator chamber shielded by 1.5-1.8m thick concrete walls. Material either prepacked or in-bulk placed in suitable containers sent into the irradiation chamber with help of an automatic conveyor. The conveyor goes through a concrete wall labyrinth, which prevents radiation from reaching the work area and operator room. When the facility is not in use the radiation source is stored under 6m deep water. The water shield does not allow radiation to escape into the irradiation chamber, thus permitting free access to personnel to carry out plant maintenance. For treating material, the source is brought to the irradiation position above the water level after activation of all safety devices. The goods in aluminium carriers or tote boxes are mechanically positioned around the source rack and are turned round their own axis, so that contents are irradiated on both the sides. [Figure 1] indicates the points at which the radiation fields were measured.
1.2 Instrument used
Teletector (Automess), Teletector with 20 m long cable probe (Automess), PLA radiation monitor (hand held unit).
| 2. Experimental|| |
The source of 60 Co is used irradiation purposes with two different strengths viz.
a) 11. kCi b) 45. 3 kCi, and (a) + (b) 56. 7 kCi
Gamma dose mapping of the area was carried out with the sources in the exposed condition.
- Source (a) 11. kCi held in exposed condition, the other source (b) 45. 3 kCi under water.
- Sources (a) + (b) 56.7 kCi held in exposed condition.
| 3. Results|| |
The results of radiation field measurements carried out at different depths for source under water are tabulated in [Table 1]. It indicates that the radiation field at a depth of 3m or more from the surface of water could be useful for planned exposure to deliver irradiation dose to the sample lowered accordingly.
|Table 1: Dose rate inside Water Pool Food irradiator (Source under water)|
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The results of radiation field measurements carried out at different distances from the sources (a) and (a) + (b) in the irradiator room for source in the exposed state are tabulated in [Table 2].
| 4. Conclusion|| |
The gamma dose mapping results are useful for planning the time period of irradiation for food materials, since presently films/dosimeters are used for the verification of irradiation dose. The gamma dose mapping of the irradiator area is useful to estimate the irradiation dose to the system materials and corresponding radiation degradation.
| 5. References|| |
Technical Specification - FIPLY irradiator (1995).
[Table 1], [Table 2]