ML090930288

Annual Report No. 49 for Ntr, 2008

ML090930288
Person / Time
Site:	Vallecitos Nuclear Center
Issue date:	03/30/2009
From:	Don Krause GE-Hitachi Nuclear Energy Americas
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
Download: ML090930288 (12)

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GE Infrastructure HITACHI Energy, Nuclear Donald R. Krause Manager, Regulatory Compliance and EHS Vallecitos Nuclear Center 6705 Vallecitos Rd Sunol, CA 94586 USA T 925 862 4360 F 925 304-7435 Donald.Krause@ge.com 30 March 2009 U.S. Nuclear Regulatory Commission One White Flint North 11555 Rockville Pike Rockville, Maryland 20852-2738 Attn: Document Control Desk

Subject:

Annual Report for NTR, 2008

Reference:

License R-33, Docket 50-73

Enclosure:

Annual Report No. 49 Enclosed is the Annual Report No. 49 for the GE-Hitachi Nuclear 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, Donald R.Krause,

Manager, Regulatory Compliance and Environment, Health, and Safety cc: Steve Pierce 4c Lo GEHitachi Nuclear Energy Americas, LLC DRK-2009-15 NTRAnn Report.doc

GE Hitachi Nuclear Energy 01 HITACHI Vallecitos Nuclear Center 6705 Vallecitos Rd Sunol, CA 94586 USA NUCLEAR TEST REACTOR ANNUAL REPORT NO. 49 FOR THE YEAR 2008 LICENSE R-33 DOCKET 50-73 MARCH 2009

NTR Annual Report No. 49 General Electric Nuclear Test Reactor Annual Report No. 49 This report summarizes the operations, 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, 2008 through December 31, 2008.

I. General Specific information about the operation of the NTR during the reporting period is presented as follows:

1. There were 233 reactor startups with the reactor operating at or above critical for 651.68 hours7.87037e-4 days <br />0.0189 hours <br />1.124339e-4 weeks <br />2.5874e-5 months <br />. Total power generation equaled 628.26 EFPH equivalent to 2.62 MW days in 2008.

2. The average radiation exposure to regular full-time NTR Operations personnel was 0.565 Rem.

3. There was one reactor scram and no unscheduled shutdowns of the reactor by the operator after reaching criticality: The scram is discussed in Section V.

4. There were no occurrences during 2008 that required notification of the NRC.

Page 1 of 10

NTR Annual Report No. 49 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 and certified NDT activities in 2008.

2. Mr. Edward Ehrlich went out on full disability on April 28th, 2008. His license was re-classified to "inactive" on May 9th, 2008 by the Manager, NTR, after confirmation of his disability claim's acceptance by all parties. Mr. Ehrlich came off disability on September 9th, 2008, and retired on September 30th, 2008. His license however, has remained inactive.

3. Mr. Thomas McConnell continued performing licensed SRO activities in 2008. He also worked as a NDT trainee under the direction of certified NDT personnel.

4. Mr. Dennis Smith continued as a part-time GE employee (pensioner) performing licensed SRO activities in 2008.

5. Mr. Peterson continued performing licensed SRO and certified NDT activities in 2008.

6. Mr. Ma'x Paronable, working as a contract employee in 2007 was hired full time in February 2008. He performed as an RO trainee and radiography technician throughout the remainder of 2008.

7. Mr. Terry Hofer continued as a part time GE employee (pensioner) performing neutron radiography and non-reactor system maintenance tasks under the direction and supervision of the licensed SRO staff and certified NDT personnel.

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NTR Annual Report No. 49 Ill. Facility Changes, Tests, Experiments, and Procedure Changes Approved by The FacilityManager 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(o), there were nine facility changes made in 2008 requiring Facility Manager, Regulatory Compliance and VTSC approval as requested.

1. CA-283, Safety Rod Replacement Part (Stop Rubberl-This change authorized a change in the material specification for the rubber parts associated with the scram dampening system on the safety rods. The material specified on the drawings was no longer available. The replacement material was evaluated as equivalent for the function intended.

2. CA-284, Safety Rod #4 Drive Alignment (Shim Installation)-This change authorized the installation of an alignment shim in the scram dampening system to regain alignment of the safety rod drive system. Without the shim, the safety rod was experiencing spurious disconnects during a withdrawal due to the friction generated between the moving and stationary parts of the scram dampening system.

3. CA-285, Safety Rod #1 Drive Alignment (Loosened Bolting)-This change authorized the operation of Safety Rod #1 with the mounting bolts for the dashpot in the scram dampening system in a less than fully tight condition. Safety Rod #1 was receiving spurious disconnects when first withdrawing the rod. An alignment was attempted without success. It was observed that the spurious disconnects were eliminated when the mounting bolts on the dashpot were left half a turn from tight. With considerations for ALARA, it was decided to allow operation of the safety rod with these bolts in the less than fully tight condition. ER 08-13 instituted a surveillance program to monitor the position of these bolts.

4. CA-161F, Modified Design for the CHRIS Carrier-This change authorizes the utilizati6n of a modified carrier designed to allow a shielded, hands-off method of irradiated sample retrieval to address ALARA concerns for long duration irradiations in the CHRIS facility.

5. CA-286, Safety Rod RUBBER STOP Inspection Results and Justification for Continued Operation-After installing new rubber on the readily accessible moving side of the safety rod scram dampening system, an inspection of the rubber attached to the stationary side of the system was performed on Safety Rod #2. This rubber was found in a deteriorated condition. With ALARA concerns in mind, it was decided to schedule Page 3 of 10

NTR Annual Report No. 49 the replacement of these rubber stops during the scheduled annual outage at the beginning of 2009. This allows the work to be performed after a two-week shutdown period giving maximum time for fission product decay. This CA provides the justification to allow continued operations with the rubber in its current condition.

6. CA-288, South Cell Door Open Lock-This CA authorizes the installation of a mechanical operator actuated latch to prevent the inadvertent closure of the South Cell Shield Door in certain operating conditions, especially when personnel enter the South Cell alone on back shift.

7. CA-289, NTR 2008 Manual Poison Sheet Repositioning-This CA authorizes the repositioning of the Manual Poison Sheet as part of a strategy to intentionally increase the excess reactivity available in the NTR core.

8. CA-290, Medical Isotope Seed Holder for CHRIS-This CA authorizes the utilization of a modified carrier in the CHRIS experimental facility during the irradiation of medical isotopes.

9. CA-292, Safety Rod Bushing Correction-This CA corrects the manufacturer's part number for the Safety Rod drive system bushings. These part numbers were incorrectly identified on the original drawing.

B. Tests Pursuant to 10CFR50.59(a), there were no special tests performed during 2008 requiring Facility Manager, Regulatory Compliance and VTSC approval as requested.

C. Experiments Pursuant to 10CFR50.59(a), there were three new experiments in 2008 requiring Facility Manager, Regulatory Compliance and VTSC approval as requested.

1. CA-161G, Titanium-Molybdenum Compound Irradiations-This CA was used to archive the Experimental Type Approval (ETA) for a non-routine experiment involving the irradiation of a titanium-molybdenum compound utilizing the CHRIS system with a modified carrier.

2. CA-287, Molybdenum Irradiation ETA-This CA establishes the irradiation of molybdenum utilizing the CHRIS as an approved experiment.

3. CA-291, Medical Isotope Irradiation ETA (InCHRIS)-This CA establishes the irradiation of medical isotopes in the CHRIS facility as an authorized experiment.

Page 4 of 10

NTR Annual Report No. 49 D. Procedure Changes Pursuant to 10CFR50.59, there were nine procedural changes initiated during 2008 to incorporate editorial or typographical corrections, technical, data, and changes to requirements, or to provide for the addition or clarification of information and reliability of performance. Changes were made with Facility Manager and Regulatory Compliance review when required. A summary of the changes is presented in the table below.

Revision Procedure Number and Summary of Changes Number Title 987 SOP 10-6 Cable-Held Made changes to the approval section on the Retractable Irradiation Non-Routine EAF to accommodate changes in the System organization chart.

988 SOP 12-26 Seismic Incorporated requirement and instructions for the Instrument PM replacement of the reservoir oil every year during routine maintenance.

989 SOP 9-5 Source, Byproduct Removed reference to EMS SOPs and assigns and Special Nuclear responsibility of external shipment compliance on Material Control, EMS.

_______Movement, and Shipment 990 SOP 10-6 Cable-Held Added an Experiment Approval Form for TI-MOLY Retractable Irradiation Irradiations. Modified the SCHAFER Experiment System Approval Form.

991 SOP 10-6 Cable-Held Modified the Experiment Approval Form for TI-Retractable Irradiation MOLY Irradiations to cover various other System Molybdenum irradiations.

992 SOP 9-3 Engineering Updated the procedure to reflect changes Release necessary to ensure form, fit, and functionality are met on parts and materials when required by Technical Specifications. Updated formatting.

993 SOP 4-2 Safety Rod Repairs Updated the procedure to reflect changes necessary to ensure form, fit, and functionality are met on parts and materials when required by Technical Specifications. Updated formatting.

994 SOP 9-15 Preventive and Updated the procedure to reflect changes Corrective Maintenance necessary to ensure form, fit, and functionality are Program met on parts and materials when required by Technical Specifications. Updated PM and CM cards. Updated formatting.

995 SOP 9-2 SOPs Made changes to the SOP format to reflect change in the company identity.

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NTR Annual Report No. 49 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 2008.

Safety Rods

• Replace the drive belt for Safety Rod #4

• Repaired a Scram Magnet broken lead wire on Safety Rod #1

" Replaced the rubber stops on the moving component of the Safety Rod dampening systems for all four Safety Rods

" Replaced burnt out capacitor on Safety Rod #4

" Performed alignments on Safety Rods #1 and #4 Seismic Instrument

• Replaced the dampening oil in the seismic instrument as a new preventative measure to preclude a significant change in oil viscosity from affecting the trip point.

PICO Power Instrumentation

" Excessive noise noted on the Pico instrumentation channel forced the replacement of all 4 CIC detectors and the cables at the detectors.

" Excessive noise noted on the Log N power instrument forced a replacement of the power supply with a shop spare unit.

• The range selector switch for Pico #2 was cleaned and lubricated to correct an internal mechanical operational problem.

Radiation Area Monitoring System

• On three (3) occasions during the reporting period, made various repairs and adjustments to the Radiation Area Monitor's detection instruments (Victoreens).

Primary Cooling System

• Replaced the ion exchange resin cartridges in the cleanup loop.

• Replaced the mechanical filter cartridge in the cleanup loop.

• Failure of the electrical starter for the primary cooling pump forced its replacement.

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NTR Annual Report No. 49 V. Unscheduled Shutdowns During the reporting period, there was one reactor scram, Scram 08-01 after reaching criticality:

A. Scram 08-0 1,Sequence of Events On September 23, 2008, at 0922, a process scram was received from 100% power initiated by a low primary flow condition. Prior to the scram, the reactor operator noted what appeared to be a gradual degradation of primary flow as was indicated on the primary flow recorder. He conferred with additional operations staff and notified the Facility Manager of this condition. The Facility Manager noted the abnormal indication, that the flow was low but stable and above the trip set point. While searching for a cause and/or solution and after, only a short period of time during consultation with the NTR staff, the flow became erratic, and a momentary dip initiated the low flow alarm and an automatic scram response.

By 0925, the Reactor operator secured the reactor and the secondary systems per standard operating procedure. The following conditions existed immediately following:

Stack gas Normal Stack Particulate Normal Rx Flow 76% - 85% and fluctuating (Normally 90%)

Rx Cell Dose Rates 50 mrem/hr Normal Control Room Dose Rates <1 mrem/hr Normal At 0930, Secondary Cooling was restarted for eight (8)minutes to complete a forced primary cool down of the primary to ambient.

At 0940, the primary coolant pump was secured and restarted. The reduced flow conditions and fluctuations continued after pump restart.

At 0949, the primary system was vented using the solenoid vent valve. Flow conditions immediately returned to normal, 90% indicated with no fluctuations.

At 1100, a Reactor Cell entry was made to determine general conditions and inspect the primary system including primary pump and vent valve. All conditions and systems were normal.

B. Scram 08-01, Investigation and Evaluation An examination of the flow recorder trace reveals that reactor flow was normal at the time of the venting evolution performed just prior to startup. A gradual reduction in flow stared Page 7 of 10

NTR Annual Report No. 49 soon after this venting evolution and continued until just prior to the time of the scram. At the time of the scram, significant fluctuations in the flow were apparent which simultaneously initiate a low flow alarm and low flow scram. An observation of the temperature recorder revealed the core temperatures were not affected by the abnormal flow conditions. The low flow alarm is initiated from a pressure switch sensing the differential pressure across the core. The low flow scram is initiated off of input from a Rosemont differential pressure transmitter inline with the reactor outlet flow.

The primary vent valve is an electric solenoid to open, normally shut spring return valve. It is located at a high point in the primary system on the suction side of the primary pump. It has been demonstrated that when the solenoid vent valve is open while the primary pump is running, the pump will quickly draw air in through the vent become air bound. Due to the fact that a simple venting evolution subsequently cleared the condition during the event's investigation, it is suspected that the vent valve did not fully reseat after the pre-startup venting evolution.

All indications show that the primary was properly vented just prior to startup. However, if the vent valve did not fully seat after the venting evolution, air may have slowly been drawn into the primary at the suction side of the primary pump. Attempts to recreate this abnormal event condition for the vent valve were unsuccessful. This "not fully seated" condition could be caused by numerous factors but could also be a one-time event. No past occurrence of this type event is known or has been found at the NTR.

C. Scram 08-01, Corrective/Preventive Actions The immediate action to shutdown, investigate, and find the probable cause of the low flow condition that led to the scram was completed at 1145 on October 23rd. As a corrective action, the Manager, NTR briefed the NTR staff on the conclusions found in this investigation and mandated the following preventive actions. For the near term, an increased level of vigilance will be recommended with special attention paid to the flow indication. The next startup will require two operators on the panel, one operator dedicated to the startup, and one dedicated to observing the primary flow indication. Prompt operator action to shutdown the reactor will be advised upon the first indication of a reduced flow or an abnormally wide flow bandwidth.

Additionally, it was recommended that the primary venting evolution be performed early in the daily prestart process. This will increase the likelihood that an abnormal flow condition caused by a failure of the vent valve to fully reseat will be recognized prior to startup.

The Manager, NTR, then authorized a return to normal operation. As of the writing of this report, there has been no reoccurrence of the vent valve's failure to reseat after venting.

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NTR Annual Report No. 49 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 stack data, these data are for the entire VNC site and include the effects of operations other than the NTR.

A. NTR Stack Total airborne releases (stack emissions) for 2008 are as follows:

Alpha Particulate: 1.11 E-6 Ci (predominantly radon-thoron daughter products)

Beta-Gamma Particulate: 4.01 E-6 Ci lodine-131: 3.52 E-6 Ci Noble Gases: 1.68 E+2 Ci Noble gas activities recorded from the NTR stack 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, 6.62 E-13 LCi/cc Weekly Average, 1.02 E-13 ltCi/cc Beta Concentration:

Weekly Maximum, 8.11 E-12 jiCi/cc Weekly Average, 3.56 E-13 ltCi/cc C. Gamma Radiation The yearly dose results for the year 2008 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. 49 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, and 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 2008, the highest annual dose to full time NTR Operations personnel was 0.786 Rem and the lowest was 0.457 Rem. The average radiation exposure to personnel was 0.512 Rem per person. The 2008 collective radiation exposure for NTR personnel was 2.559 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 10 of 10