Radioactive Tracer Test to Develop a Recycling System for Operating Reactor Scrap Metal

1994 ◽  
Vol 353 ◽  
Author(s):  
A. Umemura ◽  
K. Kimura ◽  
K. Takahashi ◽  
D. Sakurai ◽  
M. Yamamoto ◽  
...  

AbstractA demonstration test using radio-isotope(RI) tracers during the manufacturing of inner drum shielding material from the recycling of operating reactor scrap metal was completed and the following results were obtained. The behaviour of five radionuclides (Mn-54. Co-60. Zn-65. Sr-85 and Cs-137) was established. The time-dependent behaviors of the radionuclides in molten steel and in slag were investigated. The radioactivity distributions in metal products were homogeneous. Dose equivalent rates in the working area were below background levels and radioactive dust concentrations in the air were below detection limits.

Geophysics ◽  
2009 ◽  
Vol 74 (1) ◽  
pp. B1-B8 ◽  
Author(s):  
Erika Gasperikova ◽  
J. Torquil Smith ◽  
H. Frank Morrison ◽  
Alex Becker ◽  
Karl Kappler

Electromagnetic induction data parameterized in time-dependent object intrinsic polarizabilities can discriminate unexploded ordnance (UXO) from false targets (scrap metal). Data from a cart-mounted system designed to discriminate UXO of [Formula: see text] in diameter are used. Discriminating UXO from irregular scrap metal is based on the principal dipole polarizabilities of a target. Nearly intact UXO displays a single major polarizability coincident with the long axis of the object and two equal, smaller transverse polarizabilities, whereas metal scraps have distinct polarizability signatures that rarely mimic those of elongated symmetric bodies. Based on a training data set of known targets, objects were identified by estimating the probability that an object is a single UXO. Our test survey took place on a military base where [Formula: see text] mortar shells and scrap metal were present. We detected and correctly discriminated all [Formula: see text] mortars, and in that process we added 7% and 17%, respectively, of dry holes (digging scrap) to the total number of excavations in two different survey modes. We also demonstrated a mode of operation that might be more cost effective than current practice.


Author(s):  
S. S. Kerinja ◽  
U. Ibrahim ◽  
S. D. Yusuf ◽  
M. M. Idris ◽  
A. A. Mundi

In this study, the radiation exposure rate emanating from the scrap metals dumpsite was assessed using an Interceptor Spectroscopic personal radiation detector (SPRD). Sixteen (16) scrap metal dumpsites were selected at random across four Local Government Areas (Nasarawa, Lafia, Akwanga, and Keffi) of Nasarawa State, Nigeria. The gamma activity level in µrem/hr on three (3) randomly selected points on each of the scrap metal dumpsites was determined. A reading was taken on point 100 m away from each of the scrap metal dumpsite. Results show that the highest annual effective dose equivalent was observed in Akwanga (AKW4) scrap metal dumpsite with an annual effective dose equivalent of 0.2167 mSv/yr. The scrap metal dumpsite with the lowest annual effective dose equivalent was observed in Lafia (LAF3) and (LAF4) with an annual effective dose equivalent of 0.0613 mSv/yr. The excess lifetime cancer risk of 0.7585 × 10-3 was the highest value recorded in AKW4, while the lowest value was found to be 0.2146 × 10-3 in LAF3 and LAF4. The control radiation exposure level, 100 m from scrap metal dumpsites, shows the value of gamma activity level and annual effective dose equivalent obtained is ranged between 13 µrem/hr and 0.1594 mSv/yr respectively on location KEF1 to 3 µrem/hr and 0.0368 mSv/yr on locations LAF2 and LAF3 respectively. The annual effective dose equivalent values obtained were below the ICRP dose limit of 1 mSv/yr, indicating that, the environments around these scrap metal dumpsites are safe. The excess lifetime cancer risk value (ELCR) obtained in some locations is higher than the world average value of 0.29 × 10-3. Therefore, we recommend that scavengers, workers at the scrap dumpsites are to minimise the period of their stay within the dumpsites, and also the residential homes are to maintain a distance of 500 meters around the scrap metal dumpsites so as to minimise the risk of developing any health problem relating to cancer in future.


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