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The NRC received the following information … The NRC received the following information from the State of California via e-mail:</br>At about 945 am October 6, 2006, (Deleted) from Schlumberger's Houston office contacted the RHB South ICE RM office to notify RHB that a well-logging tool with two sources (1.7 Ci Cs-137 and 16 Ci Am-Be) had become stuck the day before yesterday near the bottom of the hole. They worked over the last two days, 'fishing' for the sources, and recovered the Am-Be source when the tool broke. Neither of the sources have been compromised. They have not yet determined that the remaining source must be abandoned, but expect to make that determination over the weekend, and requested approval to abandon it, if additional retrieval attempts fail. Approval was granted, and Schlumberger was provided an emergency contact number to provide information over the weekend, if any health and safety concerns arise (e.g., if the source is compromised). The well is in Kern Co., CA at Chevron USA, well no. Amber 235 in the Midway-Sunset Field (Section 26, Township 31-S, Range 22-E). </br>At 9:30 PDT on October 7, 2006, (Deleted) called again to report that they had reason to believe the Cesium-137 source had ruptured down-hole. Chevron had commenced a cut and thread fishing operation for the stuck logging tool late Wednesday evening, October 4th. On the first trip into the hole the logging tool was engaged into the grapple, when the rig started to pull out of the hole the drill pipe was stuck, the drill pipe would not move up or down. The decision was made to gently reverse rotate the pipe in an attempt to free the logging tool from the grapple. Once the tool was released from the grapple, the drill pipe was pulled out of the hole and the fishing assembly removed and replaced with wash over pipe. During the second trip in the hole with the wash over pipe the tool was engaged and part of the tool came out of the hole. This part of the tool contained the 592 GBq Am241Be source. The 63 GBq Cs-137 source remained down hole in another tool. Several more trips were made with the wash over pipe in an attempt to recover the remaining tools. It was during an attempt with the wash over pipe when Schlumberger personnel who were monitoring the mud returns notice a substantial increase on their survey meter from 0.4 mrem/hr to 7.0 mrem/hr. Since an increase such as this could indicate a potentially ruptured source all operations and circulation were immediately stopped with all personnel removed from the rig and the immediate area.</br>At this time the area around the rig, mud pit and shale shaker were cordoned off. Schlumberger personnel are conducting further surveys of all personnel and the area at this time. RHB is continuing to follow up with the licensee on this.</br>The state also reported that Schlumberger is sending additional people to the site to conduct further surveys and determine their future course of action. The state was notified of the event on 10/7/06 at 2130. </br>CA Report Number: 10070610/7/06 at 2130.
CA Report Number: 100706
16:30:00, 7 October 2006 +
42,891 +
15:00:00, 8 October 2006 +
16:30:00, 7 October 2006 +
The NRC received the following information … The NRC received the following information from the State of California via e-mail:</br>At about 945 am October 6, 2006, (Deleted) from Schlumberger's Houston office contacted the RHB South ICE RM office to notify RHB that a well-logging tool with two sources (1.7 Ci Cs-137 and 16 Ci Am-Be) had become stuck the day before yesterday near the bottom of the hole. They worked over the last two days, 'fishing' for the sources, and recovered the Am-Be source when the tool broke. Neither of the sources have been compromised. They have not yet determined that the remaining source must be abandoned, but expect to make that determination over the weekend, and requested approval to abandon it, if additional retrieval attempts fail. Approval was granted, and Schlumberger was provided an emergency contact number to provide information over the weekend, if any health and safety concerns arise (e.g., if the source is compromised). The well is in Kern Co., CA at Chevron USA, well no. Amber 235 in the Midway-Sunset Field (Section 26, Township 31-S, Range 22-E). </br>At 9:30 PDT on October 7, 2006, (Deleted) called again to report that they had reason to believe the Cesium-137 source had ruptured down-hole. Chevron had commenced a cut and thread fishing operation for the stuck logging tool late Wednesday evening, October 4th. On the first trip into the hole the logging tool was engaged into the grapple, when the rig started to pull out of the hole the drill pipe was stuck, the drill pipe would not move up or down. The decision was made to gently reverse rotate the pipe in an attempt to free the logging tool from the grapple. Once the tool was released from the grapple, the drill pipe was pulled out of the hole and the fishing assembly removed and replaced with wash over pipe. During the second trip in the hole with the wash over pipe the tool was engaged and part of the tool came out of the hole. This part of the tool contained the 592 GBq Am241Be source. The 63 GBq Cs-137 source remained down hole in another tool. Several more trips were made with the wash over pipe in an attempt to recover the remaining tools. It was during an attempt with the wash over pipe when Schlumberger personnel who were monitoring the mud returns notice a substantial increase on their survey meter from 0.4 mrem/hr to 7.0 mrem/hr. Since an increase such as this could indicate a potentially ruptured source all operations and circulation were immediately stopped with all personnel removed from the rig and the immediate area.</br>At this time the area around the rig, mud pit and shale shaker were cordoned off. Schlumberger personnel are conducting further surveys of all personnel and the area at this time. RHB is continuing to follow up with the licensee on this.</br>The state also reported that Schlumberger is sending additional people to the site to conduct further surveys and determine their future course of action. The state was notified of the event on 10/7/06 at 2130. </br>CA Report Number: 10070610/7/06 at 2130.
CA Report Number: 100706
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