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| Start date | Reporting criterion | Title | Event description | System | LER | |
|---|---|---|---|---|---|---|
| ENS 50780 | 30 January 2015 14:20:00 | Agreement State | Agreement State Report - Fixed Gauge Shutter Failed to Close | While attempting to close the shutter on a Kay-Ray fixed gauge at a coal fired power plant located at 24th and Craig Street in Omaha, NE, the cable operating the shutter mechanism broke. The gauge contained 50 mCi of Cs-137. Plant operators manually closed the gauge shutter. There were no exposures to workers in the area. The state will provide additional information when it is available.
The following event update was received from the State of Nebraska via email: The Nebraska Department of Health and Human Services, Radioactive Materials Program, was notified at 1455 hours (CST) on 01/30/2015 by the Tech. Supervisor, at Omaha Public Power District that a Kay Ray fixed gauge Model Number 7080, housing serial number 16784Y, source shutter failed to close. The device originally installed in 1984 with approximately 50 millicuries Cesium 137 now contains approximately 25 millicuries. The gauge which is part of a hopper level sensor is mounted between two fly ash hoppers approximately 20 feet off of the floor. The source closure mechanism on the gauge is connected to a handle located at floor level by a flexible cable. The closure cable are secured so that when the floor handle is operated, the control cable slides inside of the sheath thus opening/closing the shutter. One of the station's chemists was restoring the source to service following a maintenance outage. The 'external' source closure mechanism for Unit 4 precipitator was being placed in the open position when a metallic snap was heard when opening the source shutter. The source handle was half way to the open position when this noise was heard. The operator then proceeded to check the cables function by trying to move the shutter to the closed position . The source shutter did not move. Scaffolding was erected and an inspection of the device showed the source shutter was in the open position and that the cable was not connected to the gauge operating mechanism. The source shutter mechanism was moved manually to the closed position and the cable reattached and tested several times using the remote actuator. All functions were noted to be in working condition. No personnel were unintentionally exposed to radiation during this event. Cause: Defective or Failed Part. Corrective Action Information: Equipment maintenance and repairs made without engineering change to the system. Device/Associated Equipment: Kay-Ray/Sensall/Fixed Gauge, Model Number 7080, Serial Number 16784Y. Source of Radiation: Amersham, Sealed Source Gauge, Model CDC 800, Serial Number 15112-V, with a CS-137 .025 Ci source Nebraska Item Number: NE150001 Notified the R4DO (Miller) and NMSS Events Notification via email. | ||
| ENS 50493 | 23 September 2014 16:50:00 | Agreement State | Agreement State Report - Failure of a Process Gauge Shutter | The following was received from the State of Nebraska via email: The Nebraska Department of Health and Human Services, Radioactive Materials Program, was notified at 0803 CDT on 9/25/2014 by a representative of the Omaha Public Power District that a Kay Ray fixed gauge Model Number 7080 source shutter failed to close. The device contains approximately 6 millicuries of Cesium-137 originally installed in 1984 with approximately 50 millicuries. The gauge is mounted between two fly ash hoppers approximately 20 feet above the floor. The source closure mechanism on the gauge is connected to a handle located at floor level by a flexible cable. The closure cable is secured so that when the floor handle is operated, the control cable slides inside of the sheath opening/closing the shutter. The outer sheath for the cable became separated from the capture mechanism at the source. The handle on the floor would move but the linkages at the source would only move approximately � inch and then the sheath would move away from the compression fitting. The reason for operating the source shutter was to perform the semiannual function check. This type of failure has been seen in the past and is easily fixed by tightening the screw which secures the end of the cable to the structure. This requires a scaffold to be built up to the source level. NE Incident ID #: NE140005 | ||
| ENS 49797 | 5 February 2014 16:30:00 | Agreement State | Agreement State Report - Malfunctioning Source Shutter Failed to Close | The following information was received via facsimile from the State of Nebraska: The Nebraska Department of Health and Human Services was notified by a representative of the Omaha Public Power District that a Kay Ray fixed gauge Model Number 7080 source shutter failed to close. The device contains approximately 25.5 millicuries of Cesium-137. The gauge is mounted between two fly ash hoppers approximately 20 feet off of the floor. The source closure mechanism on the gauge is connected to a handle located at floor level by a flexible cable. The closure cable is secured so that when the floor handle is operated, the control cable slides inside of the sheath opening/closing the shutter. The shutter closure cable became loose where the sheath attaches to the source closure mechanism which prevented the shutter from closing. The licensee disconnected the lower part from the cable and the on/off handle. By holding on to the lower part of the sheath and sliding the internal cable, the licensee was able to close the shutter. No personnel were exposed to radiation during this event. | ||
| ENS 49238 | 5 August 2013 14:50:00 | Agreement State | Agreement State Report - Shutter Stuck on a Process Gauge | The State of Nebraska submitted the following information via email: The licensee uses fixed industrial gauges for measuring levels in fly ash hoppers at the station's precipitator building. The industrial fixed gauges contain a Cesium 137 sealed source. The Cesium 137 sources were originally installed in April, 1984, and at the time contained 50 millicuries per source. The sources were manufactured and installed by Kay Ray Inc. The gauge that experienced the event was Kay Ray Gauge, Housing Model #7080 and housing serial number 16784H. The source capsule manufacture was Amersham model no. CDC 800 and K-R Ref. Number serial number 15095 V. In accordance with their license conditions two of the station's chemists were securing the Unit #5's precipitator sources in preparation for an inspection of the precipitator. The 'external' source closure mechanism for Unit #5 precipitator's 5FA-3E & 4E hoppers did not operate as designed and the shutter did not close when the handle on the floor was operated. The radiation sources, which are part of a hopper level sensor, are mounted between two fly ash hoppers 20 feet off the floor. The source closure mechanisms are connected to a handle located at the floor level by a flexible cable. These closure cables are secured to the structures so that when the handles are operated the control cables slide inside a sheath. On the 5FA-3E & 4E source, the shutter closure cable became loose up at the source which allowed the whole cable to slide back and forth when the handle was operated to try and close the shutter. This type of failure has been seen in the past and is easily fixed by tightening the screw which secures the end of the cable to the structure. This required a scaffold to be built up to the source level. A contractor came on site at 12:30 pm (CDT) on 8/5/2013 and erected a scaffold so repairs could be made. | ||
| ENS 46632 | 20 February 2011 14:30:00 | Agreement State | Agreement State Report - Fly Ash Gauge Shutter Failure | The licensee uses industrial fixed gauges for measuring densities in fly ash hoppers. The industrial fixed gauges contain a 50 milliCurie Cesium 137 sealed source. The sources were manufactured and installed by Kay Ray, Inc. While the licensee was performing maintenance on the gauges, the remote source closure mechanism on 3 of the gauges did not operate as designed and the shutter did not close when operated by the handle on the floor. The chain that operates the source shutter mechanism 20 feet above the floor was disconnected which allowed the spring loaded shutter to close. No personnel were exposed to radiation during this event. | ||
| ENS 46420 | 15 November 2010 17:30:00 | Agreement State | Agreement State Report - Fly Ash Density Gauge Shutter Fails Open | The following report was received via fax: The licensee uses fixed industrial gauges for measuring densities in fly ash hoppers at the Stations precipitator building. The industrial fixed gauges contain a Cesium 137 sealed source. The Cesium 137 sources were originally installed in April 1984 and at the time contained 50 milliCuries per source. The sources were manufactured and installed by Kay Ray, Inc. The gauge is Model No. 7080 and housing serial number 16785-G. The source capsule manufacturer was Amersham model no. CDC 800 and K-R ref. number serial number 15485 V. The Authorized User was performing the semi-annual 'Shutter Function Test' on Unit #3's precipitator sources. The 'external' source closure mechanism for the 3FA-1B & 2B hoppers did not operate as designed and the shutter did not close when the handle on the floor was operated. The external closure cable had detached from the shutter arms. In this condition, when the shutter closure mechanism was moved, the cable that operates the source shutter mechanism 20 feet above the floor did not move the shutter to the closed position. It should be noted that this cable is an older one which has been slated for replacement. This event happened at 11:30 am. The event was reported to the Lab Supervisor and the Radiation Safety Officer (RSO) at the Ft. Calhoun Power Station was notified. No personnel were exposed to radiation during this event. | ||
| ENS 46404 | 8 November 2010 16:15:00 | Agreement State | Agreement State Report - Process Gauge Shutter Could Not Be Locked Closed | The following information was reported via fax by the State of Nebraska The licensee uses fixed industrial gauges for measuring densities in flyash hoppers at the Stations precipitator building. The industrial fixed gauges contain a Cesium 137 sealed source. The Cesium 137 sources were originally installed in April, 1984 and at the time contained 50 milliCuries per source. The Sources were manufactured and installed by Kay Ray Inc. The gauge is Model No. 7062BP, and housing serial number 17666. The source capsule manufacture was Amersham model No. CDC 800 and K-R Ref. Number serial number 15607-V. The maintenance group at North Omaha wanted to replace bags in the Unit 5 Transfer House Tertiary Collector. The Shift Supervisor and Operations was notified of the "Tag-out request" as well as the Laboratory. The first step of the "tag-out" is to secure the Transfer House level detectors, the sealed radiation sources. There are two sources in the Transfer House. Both source shutters closed properly, as indicated by surveys. The keys for the interlock Mechanism for the Primary Collector Tank could not be turned to lock the handle in the Closed Position. (Reference: Attachment 2 of Registry for the Kay-Ray Fixed Gauge Model 7062BP). The shutters for both sources remain operable, and can be opened and closed. This 'event' happened at 10:15 am. No personnel were exposed to radiation during this event. | ||
| ENS 46058 | 30 June 2010 16:00:00 | Agreement State | Agreement State Report - Shutter on Fixed Industrial Gauge Failed to Close | The following report was received via fax from the State of Nebraska: The licensee uses fixed industrial gauges for measuring densities in flyash hoppers at the Stations precipitator building. The Industrial gauges contain a Cesium 137 sealed source. The Cesium 137 sources were originally installed in 1984 and at the time contained 50 millicuries per source. The sources were manufactured and installed by Kay Ray Inc. The gauge housing Model No. is 7080. The licensee was performing the semi-annual 'Shutter Function Test' on Unit #4's precipitator sources. The 'external' source closure mechanism for the 4FA-1B & 2B hoppers did not operate as designed and the shutter did not close when the handle on the floor was operated. The external closure cable had detached from the cable clamp on the side of the hopper. In this condition, when the shutter closure mechanism was moved, the cable that operates the source shutter mechanism 20 feet above the floor, bent instead of sliding the cable to the closed position. No personnel were exposed to radiation during this event. This was the fourth similar event at the licensee's plant (March 25, 27, May 6, & June 30, 2010). On June 17, a NE DHHS (Nebraska Department of Health and Human Services), Radioactive Material inspector performed a follow-up investigation on-site. At this plant, OPPD (Omaha Public Power District) has 58 installed operating nuclear fixed gauges. At the time of the investigation, OPPD had replaced 20 of the old shutter cables with a new redesigned direct replacement cable. OPPD plans to replace all of the 58 shutter cables when they fail to operate or as time permits. | ||
| ENS 45907 | 6 May 2010 18:46:00 | Agreement State | Agreement State Report - Process Gauge Shutter Malfunction | The following information was received from the State of Nebraska via facsimile: The licensee uses fixed industrial gauges for measuring densities in fly ash hoppers at the station's precipitator building. The industrial gauges contain a Cesium 137 sealed source. The Cesium 137 sources were originally installed in 1975 and at the time contained 50 millicuries per source. The sources were manufactured and installed by Kay Ray Inc. The gauges are Model No. 7700-50. The licensee was attempting to close the shutter on the fixed gauge prior to performing maintenance. One of the external closure cables was found to be slightly bound up and only partially closed the internal source shutter. The cable closure was reopened, which reopened the source shutter up at the sealed source. Closure was tried again. This time the cable, which connects the handle at the floor to the sealed source shutter mechanism 20 feet above, bent instead of sliding the cable to the closed position. This event happened at 1346 (CDT) and was reported to the station's Shift Supervisor who in turn contacted the plant electricians to make repairs so the precipitator tag-out could continue. By 1353, the cable had been closed and the lab contacted to perform a survey to verify the source shutter was in the closed position. No personnel were exposed to radiation during this event. | ||
| ENS 45801 | 27 March 2010 14:50:00 | Agreement State | Agreement State Report - Fixed Density Gauge Stuck Shutter | The following information was received from the State of Nebraska via facsimile: The licensee uses fixed industrial gauges for measuring densities in fly ash hoppers at the stations precipitator building. The industrial gauges contain a Cesium-137 sealed source. The Cesium-137 sources were originally installed in 1975 and at the time contained 50 millicuries per source. The sources were manufactured and installed by Kay Ray, Inc. The gauges are Model No. 7700-50. The licensee was attempting to close the shutter on the fixed gauge prior to performing maintenance. One of the external closure cables was found to be slightly bound up and only partially closed the 'internal' source shutter. The cable closure was reopened, which reopened the source shutter up at the sealed source. Closure was tried again. This time the cable, which connects the handle at the floor to the sealed source shutter mechanism 20 feet above, bent instead of sliding the cable to the closed position. The 'event' happened at 9:50 am and was reported to the station's Shift Supervisor who in turn contacted the plant electricians to make repairs so the precipitator 'tag-out' could continue. By 11:00 am the (shutter) had been closed and the lab contacted to perform a survey to verify the source shutter was now in the closed position. No personnel were exposed to radiation during this event. | ||
| ENS 45794 | 25 March 2010 16:35:00 | Agreement State | Process Gauge Shutter Malfunction | The following information was received from the State of Nebraska via facsimile: The licensee uses fixed industrial gauges for measuring densities in fly ash hoppers at the station's precipitator building. The industrial gauges contain a Cesium 137 sealed source. The Cesium 137 sources were originally installed in 1975 and at the time contained 50 millicuries per source. The sources were manufactured and installed by Kay Ray Inc. The gauges are Model No. 7700-50. The licensee was attempting to close the shutter on the fixed gauge prior to performing maintenance. One of the external closure cables was found to be slightly bound up and only partially closed the 'internal' source shutter. The cable closure was reopened, which reopened the source shutter up at the sealed source. Closure was tried again. This time the cable, which connects the handle at the floor to the sealed source shutter mechanism 20 feet above, bent instead of sliding the cable to the closed position. This 'event' happened at 11:35 am and was reported to the station's Shift Supervisor who in turn contacted the plant electricians to make repairs so the precipitator 'tag-out' could continue. By 11:45 am the cable had been closed and the lab contacted to perform a survey to verify the source shutter was now in the closed position. No personnel were exposed to radiation during this event. | ||
| ENS 44001 | 29 January 2008 06:00:00 | Agreement State | Agreement State Report - Missing Tritium Sign | The State provided the following information via email: The general licensee reported a possible missing tritium sign on January 29, 2008. The sign (NRD, Inc, Model #3 T-4001, Serial # 91355) had been purchased in September of 1993. The licensee did a search for the missing sign. The search included questioning the electrical working crew leader and crew, electrical maintenance supervisor and a communication to the entire plant requesting information on the status of the sign. They also checked the area where bulbs and electrical material await recycling. The licensee believes the sign had been disposed of in the common trash. Report NE080001 THIS MATERIAL EVENT CONTAINS A "LESS THAN CAT 3" LEVEL OF RADIOACTIVE MATERIAL Sources that are "Less than IAEA Category 3 sources," are either sources that are very unlikely to cause permanent injury to individuals or contain a very small amount of radioactive material that would not cause any permanent injury. Some of these sources, such as moisture density gauges or thickness gauges that are Category 4, the amount of unshielded radioactive material, if not safely managed or securely protected, could possibly - although it is unlikely - temporarily injure someone who handled it or were otherwise in contact with it, or who were close to it for a period of many weeks. This source is not amongst those sources or devices identified by the IAEA Code of Conduct for the Safety & Security of Radioactive Sources to be of concern from a radiological standpoint. Therefore is it being categorized as a less than Category 3 source |