ML080920136
| ML080920136 | |
| Person / Time | |
|---|---|
| Site: | Vallecitos Nuclear Center |
| Issue date: | 03/28/2008 |
| From: | Latonya Mahlahla GE-Hitachi Nuclear Energy Americas |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| Download: ML080920136 (11) | |
Text
GE Hitachi Nuclear Energy
- I HITACHI LaTonya Mahlahla Vallecitos Nuclear Center 6705 Vallecitos Rd Sunol, CA 94586 USA U.S. Nuclear Regulatory Commission T925 862 4360 F 910-341-2972 One White Flint North Latonya.mohlala@ge.com 11555 Rockville Pike Rockville, Maryland 20852-2738 Attn: Document Control Desk March 28, 2008
Subject:
Annual Report for NTR, 2007
Reference:
License R-33, Docket 50-73
Enclosure:
Annual Report No. 48 Enclosed is the Annual Report No. 48 for the GE-Hitachi Nuclear Energy Test Reactor (NTR) located at Vallecitos Nuclear Center in Sunol, California.
Ifyou have questions regarding this request or additional information is required, please contact me using the contact information above.
Sincerely Yours, /
Date:
be,7 WL& 2008.03.28L 09:21:51 -07'00' /
LaTonya L. Mahlahla Mgr., Regulatory Compliance & EHS cc: Steve Pierce LLM-2008-05 NTR Annual Report
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GE Hitachi Nuclear Energy
- I HITACHI Vallecitos Nuclear Center 6705 Vollecitos Rd Sunol, CA 94586 USA NUCLEAR TEST REACTOR ANNUAL REPORT NO. 48 FOR THE YEAR 2007 LICENSE R-33 DOCKET 50-73 MARCH 2008
NTR Annual Report No. 48 General Electric Nuclear Test Reactor Annual Report No. 48 This report summarizes the operation, changes, tests, experiments, and major maintenance at the General Electric Nuclear Test Reactor (NTR), which were authorized pursuant to License R-33, Docket 50-73, and 10CFR50, Section 50.59, for the period of January 1, 2007 through December 31, 2007.
I. General Specific information about the operation of the NTR during the reporting period is presented as follows:
- 1. There were 244 reactor startups with the reactor operating at or above critical for 726.75 hours8.680556e-4 days <br />0.0208 hours <br />1.240079e-4 weeks <br />2.85375e-5 months <br />. Total power generation equaled 708.79 EFPH equivalent to 2.95 MW days in 2007.
- 2. The average radiation exposure to regular full-time NTR Operations personnel was 0.495 Rem.
- 3. There were two reactor scrams or unscheduled shutdowns of the reactor by the operator after reaching criticality: These are discussed in Section V.
- 4. There were no occurrences during 2007 that required notification of the NRC.
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NTR Annual Report No. 48 II. Organization The details of changes in the status of personnel, which occurred during the reporting period, are described as follows:
- 1. Mr. Daniel Thomas continued as Manager NTR performing licensed SRO duties. He earned his Bachelors degree (a BSTM degree with emphasis on Project Management) from DeVry University in February 2007. Mr. Thomas also fulfilled duties as an NDT Level IIduring 2007 and completed his NDT-ll1 Certification in late 2007.
- 2. Mr. Edward Ehrlich was restored to full scope SRO duties in 2007 following satisfactory completion of the required NRC medical examination. This was contingent upon his taking doctor prescribed medications to address a medical condition. His SRO license has been amended to reflect that requirement. Mr. Ehrlich continued to perform certified NDT Level III duties.
- 3. Mr. Thomas McConnell was added to the NTR staff in 2007 and subsequently passed his SRO examination. He was licensed as an NTR SRO in November 2007 and began normal SRO duties. Mr. McConnell also worked as a NDT trainee under the direction of certified Level IIand Ill NDT personnel.
- 4. Mr. Dennis Smith continued as a part-time GE employee (pensioner) performing licensed SRO duties. His NDT Certifications was allowed to lapse in October.
5., Mr. Peterson continued performing licensed RO duties. His license was renew on December 21st, 2007. Mr. Peterson also continued to perform certified NDT Level III duties.
.6. Mr. Max Paronable continued on the NTR staff in 2007 as a contract employee to perform NDT neutron radiography tasks and non-reactor system maintenance tasks under the direction and supervision of the licensed SRO staff and certified Level IIand Ill NDT personnel.
- 7. Mr. Art Raya continued on the NTR staff in 2007 as a contract employee to perform NDT neutron radiography tasks and non-reactor system maintenance tasks under the direction and supervision of the licensed SRO staff and certified Level IIand III NDT personnel. Mr. Raya retired in July.
- 8. Mr. Terry Hofer was added to the NTR staff in 2007. He was employed as a part time GE employee (pensioner) performing NDT neutron radiography tasks and non-reactor system maintenance tasks under the direction and supervision of the licensed SRO staff and certified Level IIand Ill NDT personnel.
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NTR Annual Report No. 48 Ill. Facility Changes, Tests, Experiments, and Procedure Changes Approved by The Facility Manager In accordance with written procedures, facility manager approval is required for changes to the facility, procedures, tests, and experiments. Specific information about the reporting period is presented as follows:
A. Facility Changes Pursuant to 10CFR50.59(a), there were two facility changes made in 2007 requiring Facility Manager, Regulatory Compliance and VTSC approval as requested.
- 1. Storage cabinets for photochemical storage were added to the NTR NRay film developer room and NTR shop room.
- 2. NTR photochemical PVC gravity drains piping within the wall of the NTR manager's office was inspected and found to be in good condition. The downstream photochemical drain piping, valves, and fittings, which are outside the Building 105 and terminate at the NTR photo waste tank were inspected and found to be of satisfactory integrity. That piping was replaced as a preventative maintenance item due to its exposure to the elements.
- 3. The air supply line connection to the south cell door air manifold valve come loose.
The solder joint at this fitting failed allowing the airline to blow off the manifold under normal pressurized conditions. Repairs required the line to be disconnected and re-soldered in the shop. A rated swage coupling was adopted in-line to allow a non-soldered installation of the airline to the air manifold valve to avoid hot work in the control room. This additionally allows subsequent removal if maintenance needs arise for the manifold valve. The swage coupling used is equivalent to other swage fittings already in use on other pressure connections to the same air manifold valve.
B. Tests Pursuant to 10CFR50.59(a), there were no special tests performed during 2007 requiring Facility Manager approval.
C. Experiments Pursuant to 10CFR50.59(a), there were no new experiments in 2007 requiring Facility Manager approval.
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NTR Annual Report No. 48 D. Procedure Changes Pursuant to 10CFR50.59, there were procedural changes initiated to incorporate editorial or typographical corrections and technical data, changes to requirements, or to provide for the addition or clarification of information and reliability of performance. Changes made during 2007 were made with Facility Manager approval after Regulatory Compliance review when required. A summary list of the procedural changes is presented below:
- 1. SOP 2-7 Process Instrumentation Revised (Rev. 981) to reference the approved CA for the value of the Thermopile conversion factor used for calculating the core delta T from the Thermopile mv readout.
- 2. SOP 6-8 Control Room Data Sheet Revised (Rev. 982) to remove reference to delta T conversion factor for the Thermopile and clarified language for the heat balance equation.
- 3. SOP 6-4 Daily Surveillance check Sheet Revised (Rev. 985) to add and record a check of secondary cooling flow availability prior to reactor startup.
- 4. SOP for PM 12-26 Seismic Instrument PM Revised (Rev. 986) to describe the required positioning of the internal instrument components.
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NTR Annual Report No. 48 IV. Major Preventative or Corrective Maintenance During this reporting period, all routine preventive maintenance and surveillance checks were completed as scheduled. The following lists the noteworthy corrective maintenance activities performed in 2007.
Safety Rods
- Replaced a failed Safety Rod Drive-In Limit Switch on Safety Rod #2.
- Received a spurious safety rod disconnect on Safety Rod #2. Isolated the problem to a defect in the coiled cabling providing power to the scram magnet. Repaired the cable by removing the defective section.
Seismic Instrument Discovered a misalignment of the internal components of the seismic instrument.
This made the instrument overly sensitive and caused spurious trips as was documented by Scram 07-01. Made the required mechanical adjustment to the instrument's internal components to correct the misalignment.
PICO Power Instrumentation
- Excessive noise noted on Pico channel #3 forced the replacement of the instrument's cables at the detector.
- Excessive noise noted on Pico channel #1 forced the replacement of the HV Power Supply and the 25.5 kilovolt resistor for the remote repeater meter.
Source Drive System
- Failure of the drive belt for the Source Drive forced its replacement on two (2) occasions.
Radiation Area Monitorinq System
- On nine (9) occasions during the reporting period, made various repairs and adjustments to the Radiation Area Monitor's detection instruments (Victoreens). PC Boards were adjusted and replaced when necessary to keep the system functional and operating within specifications. No common cause failure was apparent.
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NTR Annual Report No. 48 V. Unscheduled Shutdowns During the reporting period, there were two reactor scrams or unscheduled manual shutdowns after reaching criticality:
Scram 07-01 on Jan 8, 2007 was initiated by a seismic instrument trip of the reactor control system. There were no seismic events at the time of this trip as reported by the USGS. Subsequent investigations revealed that during the January 07 maintenance inspection of the instrument, the rotational orientation of the pendulum was left in a position that allowed minimal clearance between the arm that physically positions the trip contacts and the pendulum device. This was allowing any minor movement caused by airflow or vibration to complete the electric trip circuit at an area of the instrument that was designed for clearance and resulted in spurious trips.
Normally, a more significant motion of the pendulum would be required to complete the circuit at the designed contact points. The rotational orientation of the pendulum was corrected. The instrument was tested and per surveillance test procedures and was shown to provide reliable performance with no spurious trips. The VNC VTSC reviewed the event and recommended changes be made to the Preventive Maintenance (PM) Instructions that would give guidance to the operators and assist them in properly configuring the instrument. Revision 982 to SOP 12-26 Seismic Instrument PM was subsequently issued to describe and require verification of proper instrument configuration.
Scram 07-02 on Jan 15, 2007 was an operator initiated manual scram from power.
Shortly after a reactor startup to full power, the reactor primary outlet temperature reached its alarm point of 1300 F and was reportedly rapidly increasing. The reactor operator took immediate actions to reduce reactor power by driving in control rods.
This immediately reduced reactor power but was ineffective in turning the rising temperature. Concurrently, a second operator found the secondary cooling flow to indicate abnormally low and took action to increase flow by opening the secondary coolant shutoff valve. The reactor operator took action to initiate a manual scram prior to reaching 1400 F.which is the reactor safety system scram setting for reactor outlet temperature. Technical Specifications require this setting to be no more that 2220 F.
The abnormal rise in reactor temperature was due to excessive throttling of the secondary coolant shutoff valve. This valve was routinely throttled on cold days to as little as the ' turn open position based on attaining a 50% secondary flow indication.
This amount of flow was sufficient for the ambient temperature conditions exiting the day of the scram.
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NTR Annual Report No. 48 The valve used for secondary coolont control, is a gate valve. It wos concluded that the small 1/4 turn open position of the shutoff valve caused the flow to become unstable. It was postulated that minimal icing in the secondary cooling water line could have been a contributing factor, further reducing flow causing the rapid primary temperature increase.
The VNC VTSC reviewed this incident and concurred with the applied corrective action. This included revising SOP 6-4 Daily Surveillance Check Sheet to now require verification of full secondary flow availability prior to a reactor startup. Additionally, operational guidelines have been communicated in the operators Coin Log and by Memo M2007-002 dated 1/15/07, which proscribes a limitation on the throttling of secondary cooling water to not less than 60% and only after primary and secondary temperatures have stabilized for 15 minutes after a startup.
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NTR Annual Report No. 48 Vi. Radiation Levels and Sample Results at On-Site and Off-Site Monitoring Stations The data below are from sample and dosimeter results accumulated during the reporting period. Except for the NTR stock data, these data are for the entire VNC site and include the effects of operations other than the NTPR A. NTR Stock Total airborne releases (stack emissions) for 2007 are as follows-Alpha Particulate: 1.47 E-6 Ci (predominantly radon-thoron daughter products)
Beta-Gamma Particulate: 3.24 E-6 Ci lodine-131:9.48 E-6 Ci Noble Gases: 1.67 E+2 Ci Noble gas activities recorded from the NTR stock integrate both background readings and the actual releases. Background readings may account for as much as 50% of the indicated release.
B. Air Monitors (Yearly average of all meteorological stations.)
Four environmental air-monitoring stations are positioned approximately 90 degrees apart around the operating facilities of the site. Each station is equipped with a membrane filter, which is changed weekly and analyzed for gross alpha and gross beta-gamma.
Alpha Concentration:
Weekly Maximum, 5.13 E-13 ýlCilcc Weekly Average, 4.03 E-14 pCi/cc Beta Concentration:
Weekly Maximum, 6.15 E-12 pCi/cc Weekly Average, 9.35 E-14 pCi/cc C. Gamma Radiation The yearly dose results for the year 2007 as determined from evaluation of site perimeter environmental monitoring dosimeters showed no departure from normal stable backgrounds.
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NTR Annual Report No. 48 D. Vegetation No alpha, beta or gamma activity attributable to activities at the NTR facility was found on or in vegetation in the vicinity of the site.
E. Water There was no release of radioactivity in water or to groundwater greater than the limits specified in 10CFR20, Appendix B,Table 2, Column 2.
F. Off-Site The results of samples collected from off-site locations indicate normal background for the regional area.
VII. Radiation Exposure In 2007, the highest annual dose to full time NTR Operations personnel was 0.685 Rem and the lowest was 0.295 Rem. The average radiation exposure to personnel was 0.495 Rem per person. The 2007 collective radiation exposure for NTR personnel was 3.09 Person-Rem.
VIII. Conclusion The General Electric Company concludes that the overall operating experience of the NTR reflects another year of safe and efficient operations. There were no reportable events.
GE-Hitachi Nuclear Energy Americas LLC Vallecitos Operations Daniel M.Thomas, Manager Nuclear Test Reactor Page 9 of 9