Event Notification Report for February 22, 2005

PART 21 INVOLVING A DEFECT OF A DESCOTE BRAND VALVE USED ON UF6 14 TON CYLINDERS

The licensee faxed over the following information for their Part 21 report:

"Metropolis Works, Metropolis, Illinois (Uranium Conversion Facility) is reporting a potential deviation and defect of a Descote brand valve used in UF6 14 Ton Cylinders.

"While preparing to fill a new UF6 14 Ton Cylinder from Urenco (Supplier/Customer), a potential deviation was recognized during the plant procedural pre-fill 60 lb. pressure check that identified improper torque of the Descote brand valve's packing nut. Torque inspections of all new Urenco cylinders on site were initiated when the deviation became apparent in four cylinders. A total of 57 cylinders at the plant were found to be outside the required torque specifications for these new 14 Ton UF6 cylinders. All of these valves on-site have been properly torqued as of 2/23/05.

"Secondly, one of the valves noted above was re-torqued and passed the procedural pressure check after which the filling process proceeded. Upon filling the cylinder, a small, localized seepage occurred that was controlled immediately per procedure. The cylinder was isolated and allowed to cool (liquid to solid phase) to facilitate valve replacement and further investigation of the valve. During the investigation on 2/22/05, two issues were apparent including improper seating of the valve (though no obvious signs were recognized) and a potential minor crack/imperfection was recognized on this 613 packing nut under magnification. This valve is being prepared to send off site for detailed metallurgical analysis. MTW personnel have communicated this inconsistency with the certifying organization (Urenco) and determined this is a reportable event as a defect per 10 CFR 21.21 requirements and plant procedures.

"No workers have received a chemical exposure from this issue and no material release from the facility occurred.

"Marking on the valve are as follows (comments):

"Descote Valve
Type 51.1 valve (revision # /size)
N-1000 (in casting)
11 246 (valve #/type:)

"Opposite side of valve (manufacture information)
0011068173
557 R05
204250
636 made in France

"Packing Nut Information
613
579 R08
51.1 Type"

Licensee notified NRC personnel Dave Hartland, Region 2 and Michael Raddatz NRC HQ.

EMERGENCY DIESEL GENERATOR AND EMERGENCY FEEDWATER AUTO START ON VITAL BUS FAILURE TO TRANSFER

"To support routine preventative maintenance on the 4160V Unit Auxiliary Transformer breaker, 4160V Vital Bus 5 did not successfully transfer to the Reserve Auxiliary Transformer. Bus 5 momentarily de-energized and the Emergency Diesel Generator started and loaded as expected supplying Bus 5. The Emergency Feedwater System actuated as expected on momentary undervoltage to Bus 5. The plant remains stable at 100% power. A station troubleshooting team has been established.

"The reason that Bus 5 did not transfer to the Reserve Auxiliary Transformer is not known at this time."

The licensee notified the NRC Resident Inspector.

REPORT OF MISSING SPECIAL NUCLEAR MATERIAL

The following details were provided by the licensee via email after the telephonic notification:

"This is a non-emergency Event Notification in accordance with 10 CFR 20.2201(a)(1)(ii) to inform the NRC of missing special nuclear material (SNM) (up to approximately 0.15 grams of U235). The missing SNM consists of one complete and three partial in-core detectors.

"Since June 2004, Pacific Gas and Electric (PG&E) has been performing an investigation and search for three missing 18-inch rod segments at the Humboldt Bay Power Plant (HBPP) (reference NRC Event Notifications 40877 and 40963). The investigation also included a verification of the inventory of all SNM, including fuel and non-fuel SNM. As a result of the investigation, plant personnel identified HBPP records that indicate 54 in-core detectors should be in the spent fuel pool (SFP).

"In-core detectors were used inside in-core assemblies during plant operations to measure reactor power level. There were three in-core detectors contained inside each in-core assembly. The in-core assemblies were segmented for storage, and the in-core detectors from a total of 18 in-core assemblies (containing 54 in-core detectors) should be onsite. Each in-core detector is approximately 2-1/2 inches long. Depending on design, an in-core detector contains as much as 0.04 grams of U235, to slightly less than 0.002 grams of U235.

"PG&E personnel performed a search in the SFP for the in-core detectors from December 2004 through February 2005. On February 4, 2005, PG&E determined that not all 54 in-core detectors could be located and informed the NRC. PG&E is submitting this Event Notification in accordance with 10 CFR 20.2201(a)(1)(ii) that requires a telephonic report and an Event Notification to be made within 30 days from February 4, 2005.

"PG&E will be issuing a press release tomorrow that includes this issue.

"PG&E's search for in-core detectors is complete. PG&E has determined that 50 complete and three partial in-core detectors are in the SFP. Therefore, one complete and three partial in-core detectors are missing. The partial in-core detectors appear to have been cut when the in-core assemblies were cut to be shortened for SFP storage in the mid-1970s or mid-1980s.

"Most probable locations for the missing in-core detectors are licensed, monitored and restricted radiological control areas, therefore the public health and safety has not been adversely affected.

"PG&E will issue licensee event report (LER) 2005-001-00, 'Missing In-core Detectors,' dated February 22, 2005, to be submitted in accordance with 10 CFR 20.2201(b)(2)(ii) (Reference PG&E Letter HBL-05-002). Information pertaining to the missing in-core detectors is also included in the HBPP SNM Control and Accountability Project Interim Reports, to be submitted February 22, 2005 (Reference PG&E Letter HBL-05-001).

"NRC personnel at headquarters and in Region IV have been notified of the status of this issue."

AGREEMENT STATE REPORT - MISPLACED SOURCE CAUSES POSSIBLE OVEREXPOSURE

At approximately 0600 on 2/22/07 while loading a well logging source (Gulf Nuclear CSV H90 1 Curie Cs-137 source) into the pig on the truck, the crew unknowingly dropped the source in the motor pool parking lot. The source was picked up by a mechanic at approximately 0900 and he put it in the pocket of his jacket. He did not realize that it was radioactive, but thought it might be a part to something. The mechanic wore the jacket for about 4 hours. He visited several businesses including a sandwich shop. He hung the jacket in the break room where it remained for the remainder of the day and over night. On 02/23/07, the mechanic put the jacket back on. The well logging crew returned to the facility at approximately 0600 and discovered that the source was missing when they unpacked their equipment. The crew did not discover the missing source earlier because they did not need to use the source on a job site. The crew immediately started a search for the source. The mechanic produced the source when he heard that it was missing. In total the mechanic wore the jacket about 5.5 hours over the 24 hour period. This is an estimate based on an interview with the mechanic who was uncertain about the exactness of his recollection for the time he wore the jacket.

The mechanic and a couple of coworkers were taken to a local hospital emergency room and examined. No abnormalities were noted. They are scheduled to return to the emergency room on 2/24/07. Oklahoma continues to investigate. There has been no media interest.

The R4 PAO (V. Dricks) was also notified.

* * * UPDATE ON 02/24/07 AT 1025 EST BY MIKE BRODERICK TO MACKINNON * * *

Patient received two white blood cell counts, one on 02/23 and the other on 02/24, at Integris Baptist Hospital, Oklahoma City, Oklahoma, and both white blood cell counts were normal. The Doctor does not think the patient received a large dose. Patient is to report back in 1 week for follow-up testing.

A blood sample of the patient will be sent to RPA located in London, England for chromosome analysis.

R4DO ( Bill Jones) and NMSS EO (Joe Holonich) notified.

* * * UPDATE ON 02/24/07 AT 1228 EST BY MIKE BRODERICK TO W. GOTT * * *

The patient visited the hospital emergency room again on 2/24/07. The ER Physician stated there was no sign of radiation effects. Oklahoma is arranging for the exposed individual to see a radiologist and/or oncologist at the OU Health Sciences Center. Blood samples will be drawn and provided to RPA in the UK for chromosome analysis. The state investigation is continuing.

R4DO ( Bill Jones) and NMSS EO (Joe Holonich) notified.

* * * UPDATE ON 02/26/07 AT 1117 EST BY MIKE BRODERICK TO P. SNYDER * * *

The state provided a matrix of dose rate readings taken around the source by the licensee. The state is evaluating the information. The NRC continues to interface with the state on this event.

Notified R4 (C. Cain), R4DO (D. Powers) and NMSS EO (S. Wastler).

* * * UPDATE ON 02/26/07 AT 1255 EST BY MIKE BRODERICK TO J. KNOKE * * *

"When the mechanic removed the jacket containing the source, he initially hung it on a bollard (cement & metal post to keep vehicles away from a building) outside the logging company office. It was there all afternoon, the assistant mechanic stated that he was working in that area, so he has the possibility for exposure. The mechanic who was the main exposed person moved the jacket to the company break room at quitting time. There were staff working around the clock Thursday night, so there is a definite possibility staff were near the jacket while it was hanging there. Fortunately, the break room is small (more like a large closet) so most likely they would have gotten coffee and left. We will be interviewing staff this afternoon to try to nail this down."

"The exposed individual will see a very well-qualified physician, this afternoon. DEQ staff asked him to sign medical releases authorizing release to DEQ and to NRC. A blood sample will be taken and shipped to England for chromosome analysis.

"DEQ staff will be doing interviews this afternoon with facility staff who were potentially exposed to the source. DEQ staff will use this information to determine who else may warrant medical follow-up. We will also get confirmatory readings on the radiation level of the source with an ion chamber (as opposed to the GM tubes used by the company measures sent earlier).

Notified R4 (C. Cain) Email only, R4DO (D. Powers) and NMSS EO (S. Wastler).

* * * UPDATE ON 02/26/07 AT 1908 EST BY MIKE BRODERICK TO W GOTT * * *

"The primary exposed individual ('A') has been seen by a physician from the OU Health Sciences Center who has strong radiation protection credentials. The physician's belief is that the patient will probably suffer radiation burns on his abdomen, and possibly on his fingertips. He doesn't expect any other short-term effects. No burns or other effects are visible now. There is no sign of GI tract syndrome. 'A' is going to have follow-up visits with the physician at one week and two weeks, and possibly additional visits.

"A blood sample has been taken from 'A' and tomorrow it will be shipped to England for chromosome analysis. There was some delay due to international shipping requirements for biohazardous material.

"DEQ and OU HSC staff worked together this afternoon to take measurements using ion chambers. The measurements showed lower readings than those calculated through inverse square law. We will prepare a detailed report tomorrow and send it. In short, the dose level with the ion chamber case in contact with the source was 3.3 rem/hour, falling off to 139 mrem/hour at one meter. A badge was exposed to the source at one inch for 3 minutes 35 seconds, and is being sent to Landauer for emergency processing, which will give us more information.

"DEQ staff interviewed additional personnel at the licensee this afternoon, focusing on determining who might have been exposed to excess dose other than 'A.' Tentatively, the most at-risk individual appears to be a coworker who rode with 'A' to lunch. While they were in the cab of a pickup truck, the coworker was sitting in the passenger seat on the opposite side of 'A's' body from the source, and across a sandwich shop booth from 'A' during lunch. After lunch, 'A' and the coworker worked together on a logging truck with the coat (and source) hanging a couple of yards away. They spent most of their time under the truck, which would have provided considerable shielding. Tentatively we think it is conceivable the coworker broke the limit for dose to the public, but doubt there was medically significant exposure. We will do a detailed analysis tomorrow to test this."

Notified R4DO (D. Powers) and FSME EO (J. Holonich)

* * * UPDATE PROVIDED BY MIKE BRODERICK TO JEFF ROTTON VIA EMAIL AT 1723 EST ON 02/27/07 * * *

"The results for the dosimeter that was exposed to the Cesium source at one inch for 3 minutes 35 seconds were reported from Landauer this afternoon. Deep dose was 16,106 mrem and shallow dose was 15,374 mrem. This works out to about 4.4 R/minute or 264 R/hour skin dose.

"The package containing the blood sample from 'A' was shipped to England via overnight delivery this afternoon. Results are expected in the first half of next week."

The results of the examination of 'A' by an OUHSC radiologist have been received and will be combined with the ER records from the weekend and faxed to the NRC on 02/28/07. The results were not substantially different from the verbal report on 02/26/07 and described in the update on the afternoon of 02/26/07.

Notified R4DO (Powers) and FSME EO (Mohseni).

* * * UPDATE PROVIDED BY MIKE BRODERICK TO BILL HUFFMAN AT 0030 EST ON 03/01/07 * * *

OK DEQ provided corrections to the previous report information. Specifically, the well logging source was originally reported to be a directional source. DEQ states that the source was not a directional source. In addition, the update on 2/27/07 reported a dose rate of 4.4 mrem/minute. This should have been 4.4 Rem/minute. The text of the previous report information has been corrected accordingly.

Notified R4DO (Powers) and FSME EO (Davis).

* * * UPDATE PROVIDED BY MIKE BRODERICK TO HUFFMAN AT 1000 EST ON 03/01/07 VIA E-MAIL * * *

The blood sample for chromosomal analysis has arrived in England and been received in good condition. They advise us they expect results on Tuesday.

Notified R4DO (Powers) and FSME EO (Morell).

* * * UPDATE PROVIDED BY MIKE BRODERICK TO JASON KOZAL AT 1524 EST ON 03/01/07 VIA E-MAIL * * *

"This morning the DEQ investigators visited the facility. We met with corporate management. They briefed us on their investigation and steps so far. They are doing root cause analysis of the incident. They will be doing several equipment upgrades to reduce exposure and increase certainty in handling sources. As a temporary measure they have removed the sources of the type in the incident (which did not have positive engagement of the source with the handling stick) from service until the handling sticks can be upgraded. They are doing additional staff training and will be seeking to change the safety culture at the company. As a temporary measure, they have a policy that a member of management must be present during all source handling at the shop. We explained our enforcement process to them. We informed management that based on calculations by NRC and DEQ, it appeared that a coworker of 'A' may have exceeded the dose limit for non-radiation workers, with a calculated dose of 140 mrem. We met with the coworker and explained his potential exposure, setting it in context by comparing it to the dose rate from natural background and the dose limits for radiation workers. As a precautionary measure, the company expects to do medical follow-up for this worker's exposure. We met with 'A' to follow up on his visit with a radiologist on Monday. He complained of nervous stress, but stated he had experienced no sensitivity or evidence of burns in the affected areas. We urged him to contact the radiologist immediately if he experienced any of the expected radiation symptoms. We asked 'A' some questions to clarify his interactions when he unknowingly had the source with him off-site. It does not appear that there was anyone off-site who had enough potential exposure to warrant follow-up."

Notified R4DO (Powers) and FSME EO (Morell).