Article carrying-out monitor

1. An article carrying-out monitor comprising:

a monitor part including a radiation detector to monitor an article to be inspected;

a carrying-in conveyor that carries a tray, on which an article to be inspected is put, into the monitor part;

a carrying conveyor that conveys the tray in the monitor part; and

a carrying-out conveyor that carries a tray, on which an article to be inspected is put, from the monitor part in order to inspect the presence of contamination, by radioactive substances, on an article to be inspected carried out from a controlled area of a facility, in which radioactive substances are handled;

wherein the detector in the monitor part includes a lower surface detector disposed below a path of conveyance of an article to be inspected, an upper surface detector disposed above the path of conveyance of an article to be inspected, a front, lower surface detector disposed forwardly of the lower surface detector, a front, upper surface detector disposed forwardly of the upper surface detector, a rear, lower surface detector disposed rearwardly of the lower surface detector, a rear, upper surface detector disposed rearwardly of the upper surface detector, a left, lower surface detector disposed leftward of the lower surface detector, a left, upper surface detector disposed leftward of the upper surface detector, a right, lower surface detector disposed rightward of the lower surface detector, and a right, upper surface detector disposed rightward of the upper surface detector; and

wherein the monitor part detects the presence of contamination on a lower surface of an article to be inspected on the basis of a lower surface detection signal from the lower surface detector, detects the presence of contamination on an upper surface of an article to be inspected on the basis of an upper surface detection signal from the upper surface detector, detects the presence of contamination on a front surface of an article to be inspected on the basis of a front, lower surface detection signal from the front, lower surface detector and a front, upper surface detection signal from the front, upper surface detector, detects the presence of contamination on a rear surface of an article to be inspected on the basis of a rear, lower surface detection signal from the rear, lower surface detector and a rear, upper surface detection signal from the rear, upper surface detector, detects the presence of contamination on a left surface of an article to be inspected on the basis of a left, lower surface detection signal from the left, lower surface detector and a left, upper surface detection signal from the left, upper surface detector, and detects the presence of contamination on a right surface of an article to be inspected on the basis of a right, lower surface detection signal from the right, lower surface detector and a right, upper surface detection signal from the right, upper surface detector to perform monitoring.

2. The article carrying-out monitor according to claim 1 , wherein the detector in the monitor part comprises:

a lower detection part comprising lower divided sensors (i, j) arranged in a matrix configuration below a path of conveyance of an article to be inspected, which matrix comprises i (i=1 to m) columns in a direction substantially parallel to the path of conveyance and j (j=1 to n) rows in a direction substantially perpendicular to the path of conveyance; and

an upper detection part including upper divided sensors (i, j) arranged in a matrix configuration above the path of conveyance of an article to be inspected, which matrix comprises i (i=1 to m) columns in a direction substantially parallel to the path of conveyance and j (j=1 to n) rows in a direction substantially perpendicular to the path of conveyance;

wherein the monitor part performs monitoring for determination of the presence of contamination on an article to be inspected, selecting a detection signal, which has a large signal strength, among:

lower surface detection signals being (m−2)×(n−2) in number and output from the lower surface detector, which comprises lower divided sensors (i, j) being (m−2)×(n−2) in number with i=2 to (m−1) and j=2 to (n−1); upper surface detection signals being (m−2)×(n−2) in number and output from the upper surface detector, which comprises upper divided sensors (i, j) being (m−2)×(n−2) in number with i=2 to (m−1) and j=2 to (n−1);

front, lower surface detection signals being (n−2) in number and output from the front, lower surface detector, which comprises lower divided sensors (i, j) being (n−2) in number with i=1 and j=2 to (n−1);

front, upper surface detection signals being (n−2) in number and output from the front, upper surface detector, which comprises upper divided sensors (i, j) being (n−2) in number with i=1 and j=2 to (n−1);

rear, lower surface detection signals being (n−2) in number and output from the rear, lower surface detector, which comprises lower divided sensors (i, j) being (n−2) in number with i=m and j=2 to (n−1);

rear, upper surface detection signals being (n−2) in number and output from the rear, upper surface detector, which comprises upper divided sensors (i, j) being (n−2) in number with i=m and j=2 to (n−1);

left, lower surface detection signals being (m−2) in number and output from the left, lower surface detector, which comprises lower divided sensors (i, j) being (m−2) in number with i=2 to (m−1) and j=1;

left, upper surface detection signals being (m−2) in number and output from the left, upper surface detector, which comprises upper divided sensors (i, j) being (m−2) in number with i=2 to (m−1) and j=1;

right, lower surface detection signals being (m−2) in number and output from the right, lower surface detector, which comprises lower divided sensors (i, j) being (m−2) in number with i=2 to (m−1) and j=n; and

right, upper surface detection signals being (m−2) in number and output from the right, upper surface detector, which comprises upper divided sensors (i, j) being (m−2) in number with i=2 to (m−1) and j=n.

3. The article carrying-out monitor according to claim 2 , wherein the lower detection part is not formed with the lower divided sensor ( 1 , 1 ), the lower divided sensor (m, 1 ), the lower divided sensor ( 1 , n), and the lower divided sensor (m, n), and wherein the upper detection part is not formed with the upper divided sensor ( 1 , 1 ), the upper divided sensor (m, 1 ), the upper divided sensor ( 1 , n), and the upper divided sensor (m, n) to provide spaces at four corners of the monitor part.

4. The article carrying-out monitor according to claim 2 , further comprising a positioning device that makes both a vertical distance between the lower detection part and an article to be inspected and a vertical distance between an article to be inspected the upper detection part predetermined distances.

5. The article carrying-out monitor according to claim 3 , further comprising a positioning mechanism that makes both a vertical distance between the lower detection part and an article to be inspected and a vertical distance between an article to be inspected the upper detection part predetermined distances.