ML20070P085

GE Annual Rept 31,1990

ML20070P085
Person / Time
Site:	Vallecitos Nuclear Center
Issue date:	12/31/1990
From:	Cunningham G, Danni Smith GENERAL ELECTRIC CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 9103260359
Download: ML20070P085 (7)

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e s'> 5 March 22, 1991 U. S. Nuclear Regulatory Commission Washington, D.C. 20555 Attention: Document Control Desk

Reference:

License R-33, Docket 50-73 Gentlement Enclosed are three siglied copies of Annual Report No. 31 fer the General Electric Nuclear Test Reactor.

Sincerely, GYb a G. E. Cunningham senior Licensing Engineer (415) 862-43r,o

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GENERAL ELECTRIC ,

NUCLEAR TEST REACTOR 1 ANNUAL REPORT N0. 31 LICENSE R-33 DOCKET 50-73 4

GE NUCLEAR ENERGY VALLECITOS NUCLEAR CENTER PLEASANTON, CA 94566

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CENERAL ELECTAIC NUCLEAR TEST REACTOR ANNUAL REPORT NO. 31 2

1. INTRODUCTION This report summarizes the operation, changes, tests, experiments, and major maintenance at the Nucicar Test Reactor (NIR) which were authorized pursuant to License R 33 and 10CFR50, Section 50.59, for the period Janua.y 1,1990, through December 31, 1990.

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II. CENERAL A. The reactor was operated at or above critical for 869.05 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br />; 375 startups were made. There were three scrams during this report period.

Total plant operation equaled 3.475 MW days in 1990.

B. The average radiation exposure to facility personnel was 2.06 Rem.

C. There were no occurrences during 1990 that required notification of the NRC.

D. There wete no notices of violation issued as the result of NRC inspections.

III. ORGANIZATION o

There were no organizational changes in 1990.

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t' NTR Annus1 Report No. 31 L ,

IV. CHANGES, TESTS, AND EXPERIMENTS APPROVED BY THE FACILITY MANAGER A. Changes Pursuant to 10CFR50.59(a), the Facility Manager authorized the following change in 1990.

Low Flow Bypass Modification

Description:

This change provided the authorization and documentation to move the primary coolant system low flow scram i bypass from a switch on the Log N recorder to a spare Los N trip unit in the Log N amplifier.

Safety Analysis: The new system will be more reliable, and all postulated failures are in the conservative, unbypassed condition.

B. Tests Pursuant to 10CFR50.5?(a), there were no special tests perfctmed during 1990 which required the approval of the Facility Manaber.

C. Experiments There were 1,016 individual experiments reviewed, approved, and performed in 1990. Three experiment type approvals were reviewed and approved. These are discussed below.

1. Transistor /Semiconduct< d rndjations Q,e sc rip t ion : An experiment was authorized to expost 'eistors and semiconductors to a high energy neutrou environmer- ,

determine physical and lunctional damage of the device. '1he s e irradiations were performou cn the reactor east face.

An addendum s t.ia experiment authorized the addition of paraffin and cadmiun ti reduce the thermal neutron fluence to some of the con snents under test. The purpose was to reduce thermal neutron damage to the comp,.ents.

y Safety Analvris: All e.ctu ities were performed in accordance with standard operating proced.res. The only potential hazard associated with this experiment is direct radiation from thermal noutron activccion. Radiation levels were insignificant.

For the addendum the only potential hazard was the potential for reduction of neutron flux to the ion chambers for the #2 and 93 picoammeter channals. This potential was recognized and adjustments made during the startup.

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C. Experiments (Continued) 2, Eission Chamber irradiations DescriE112D: An addendum was made to an existing experiment type approval (approval CIC/SRM, 1987), This addendum authorized placing tw9 miniature fission chambers in the herizontal cavity to tect a -> t aer source and wide range monitor amplifier'. and preampli"' 4 Safety Analysis: Potential hazards of this test a~e reactivity effects and radiation hazards to operations personnal. Threte were analyzed and found to be acceptable.

3. Permali Shieldinc Irradiation

Description:

Several irradiated and unirradiated sampics of a plastic. impregnated wood shielding material were subjected to fast neutrons at the NTR to determine if the shielding properties had been degraded by long term exposure to neutrons. Neutron i transmission was measured by the activation of foils behind the samples, Safety Atialys i s : The irradiated foils were sent to Building 103 and handled according to VNC safety practices, The reactivity of the reactor was not affected.

V, VAJOR PREVEFTIVE OR CORRECTIVE MAINTENANCE a

There were no major preventive or corrective m '.ntenance activitier performed in 1900.

VI. UNSCHEDULED SHUTDOWNS There were three (3) automatic scrams dering this report period:

A. A loss of-flow scram due to primary coolant pump cavitation from air leaked into the system through the pump seal. It was corrected by i rebuilding pump. Lost time was approximately 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />.

B. Two of three high-level pico-trip. The lost time was 17 minutoc.

C. Losr of site AC power. The lost time was 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> and 45 t inutes, v

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4-4 ' NTR Annual Report No. 31-VII. RADIATION LEVELS AND SAMPLE RESULTS AT ON AND OFF SITE MONITORING STATIONS The data below are from sample and dosimeter results accumulated during 1990.

Except for the NTR. stack data, these data are for the entire VNC sitt and include the effects of operations other than the NTR, A. NTR Stack Total airborne releases (stack emissions) for 1990 are as follows.

Alpha Particulate, < 0.10 pCi (predominantly r.uon thoron daughter products)

Beta-Gamma Particulate, < 0.76 pCi Iodine 131, 53.0 pCi Noble Cases, 2.33 x 101 Ci Noble gas ac.-ivities recorded from the NTR stack integrate background readings with the actual releases which may account for 40 to 50% of the indicated release.

B, Air MPQ112Kg (Yearly average of all meteorological stations.)

Four environmental air monitoring tations are positioned approximately 90 degreet apart around the operat ' facilities of the site. Each station is equipped with a membrar. filter which is changed weekly and analyzed for gross alpha and gross beta gamma, Alpha Concentration:

Maximum < 6,4 x 10-15 Ci/cc (predominantly radon thoron Average < 3,6 x 10 -15 pCi/cc Beta Concentration:

Maximum < 8,6x10'ff4pCi/cc Average < 2.59 x 10 pC1/cc C. Gamma Radiation The yearly dose results for the year 1990 as determined from evaluation of site periaeter TLD environmental monitoring dosimeters showed normal background, D, Etatiation 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.

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E. Enler There was no release of radioactivity in water or to the ground water greater than those limits specified in 10CFR20, Appendix B, Table II, Column 2.

F. Off-Site Samples taken off the site indicate normal background for the area.

VII7. RADIATION EXPOSURE The highest annual dose to NTR Operations personnel was 2.45 Rem, and the lowest was 1.52 Rem. The average dose was 2.06 Rem per percon.

IX. CONCLUSIONS The overall operating experience of the Nuclear Test Reactor reflects another year of safe and efficient operations. There were no reportable events.

GENERAL ELECTRIC COMPANY Irradiation Processing By  %

D. R. Smith, Manager Nuclear Test Reactor l

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