ML19256F280

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Monthly Operations Rept 70 for Oct 1979
ML19256F280
Person / Time
Site: Fort Saint Vrain Xcel Energy icon.png
Issue date: 11/01/1979
From: Gahm J
PUBLIC SERVICE CO. OF COLORADO
To:
Shared Package
ML19256F278 List:
References
NUDOCS 7912180429
Download: ML19256F280 (5)


Text

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T PUBLIC SERVICE COMPANY OF COLORADO FORT ST. VRAIN NUCLEAR GENERATING STATION MONTHLY OPERATIONS REPORI NO. 70 OCTOBER, 1979 i

j 1608 236 g i

7 912180

This report contains the highlights of the Fort St. Vrain, Unit No.1 activities ,

operated under the provisions of the Nuclear Regulatory Commission Operating License, DPR-34. This report is for the month of October,1979.

1.0 NARFSCIVE

SUMMARY

OF OPERATING EXPERIENCE AND MAJOR SAFETY RELATED MAINTENANCE 1.1 S3mmary The turbine generator was placed on line at 1303 hours0.0151 days <br />0.362 hours <br />0.00215 weeks <br />4.957915e-4 months <br /> October 2,1979, and remained on line until 0800 hours0.00926 days <br />0.222 hours <br />0.00132 weeks <br />3.044e-4 months <br /> October 14, 1979. At this time, attempts to repair a faulty buffer helium dryer on line resulted in a complete plant shutdown.

The turbine generator was again placed on line at 2303 hours0.0267 days <br />0.64 hours <br />0.00381 weeks <br />8.762915e-4 months <br /> October 23, 1979. Calibration of instrumented control rod drives in regions 5 and 35 was completed per RT-486, Part III, at 60% power. Fluctuation testing per RT-500G was completed in the 60 to 70% power range prior to the scheduled plant shutdown on October 26, 1979 Surveillance tests were accomplished at various plant cenditions during the orderly shutdown.

Fuel handling machine checkouts were completed in preparation for installation of the core region constraint devices.

1.2 Operations Reactor power was increased from 10.7% on October 1,1979, to 28% on October 2, 1979. The turbine generator was synchronized and placed on line at 1303 hours0.0151 days <br />0.362 hours <br />0.00215 weeks <br />4.957915e-4 months <br /> October 2,1979. Rise to power above 30% was hindered by condensate water conductivity and inadequate condensate in storage tanks to regenerate the demineralizer beds. Numerous valve leaks prevented the condensate makeup system from building up adequate levels in the storage tanks to accomplish demineralizer bed regeneration.

Problems were also encountered with the circulator buffer helium d ryer. Helium dryer cross tower leakage resulted when the seat in HV-21352 failed on October 5,1979. The buffer ha.lium dryer was temporarily bypassed to accomplish an on-line repair of HV-21352.

In the process of returniag the buffer helium dryer to service, circu-lators A and D tripped on abnormal buffer helium flows. ' A' and ' D' circulators were subsequently returned to service.

Mini oscillations, in-core outlet temperatures, module main steam temperatures, reheat steam temperatures, and primary coolant flow was noted after power was increased from 43% to 65% on October 10, 1979. Reactor power was reduced to 57% in two steps, and the mini oscillations continued for approximately one hour af ter the second

[ reduction before the plant stabilized. These mini or millations were

initially attributed to control system instability. The core may
have been fluctuating; however, the amplitude of the variations in 3

8 1608 237

1.0 NARRATIVE SUmfARY OF OPERATING EXPERIENCE AND MAJOR SAFETY RELATED MAINTENANCE (continued) 1.2 Operations (continued) individual nuclear channel deviations from average, main steam tempera-tures, etc., did not appear large enough to fulfill the requirements of a fluctuation. The data recorded from this period of time has not been fully evaluated.

Reactor power was increased slowly from 58% to 64% on October 12, 1979.

The mini oscillations which had previously been observed did not re-appear.

Results personnel were stened to the site at approximately 0315 hours0.00365 days <br />0.0875 hours <br />5.208333e-4 weeks <br />1.198575e-4 months <br /> on October 14, 1979. Higher than normal pressure had been ob-served by the Reactor Operator in the low pressure separator. The high pressure in the low pressure separator was observed af ter the buffer helium dryer controls had automatically switched from ' A' dryer tower to 'B' dryer tower. In the past, this problem had been traced to a faulty valve seat in HV-21352. Procedures necessary to effect an on-line repair of HV-21352 were initiated. Reactor power was reduced to achieve an average core outlet temperature to less than 1,200 'F in anticipation of bypassing the buffer helium dryer.

The events which followed resulted in tripping ' A' and 'D' circu-lators on abnormal buffer helium flows. Buffer helium supply to the operating circulators (B and C) was lost. This allowed primary coolant to flow down the shaft of the operating circulators untiJ buffer supply could be re-established. A minute amount of radioactive gas was released to the Reactor Building and reactor building exhaust system through System 21 relief valves and the steam jet air ejector.

The main turbine generator tripped on low main steam temperature (800 *F) at 0800 hours0.00926 days <br />0.222 hours <br />0.00132 weeks <br />3.044e-4 months <br />. The reactor was shutdown until a complete assessment of the upset could be completed.

Rise to power commenced on October 18, 1979, and was delayed several days due to secondary water chemistry problems. The generator was synchronized and placed on line at 2303 hours0.0267 days <br />0.64 hours <br />0.00381 weeks <br />8.762915e-4 months <br /> on October 23, 1979.

Reactor power vas raised to 63% on October 24, 1979, and the core resistance was adjusted for fluctuation testing. Instrument control rod drive calibration was performed at 0200 hours0.00231 days <br />0.0556 hours <br />3.306878e-4 weeks <br />7.61e-5 months <br /> on October 25, 1979.

Fluctuation testing was started at 0946 hours0.0109 days <br />0.263 hours <br />0.00156 weeks <br />3.59953e-4 months <br /> and completed at 2230 hours0.0258 days <br />0.619 hours <br />0.00369 weeks <br />8.48515e-4 months <br /> on October 25, 1979.

Reactor power was reduced on October 26, 1979. The turbine generator was manually tripped at 0815 hours0.00943 days <br />0.226 hours <br />0.00135 weeks <br />3.101075e-4 months <br />, followed by a manual scram at 1330 hours0.0154 days <br />0.369 hours <br />0.0022 weeks <br />5.06065e-4 months <br />. The main condenser was isolated in preparation for con-denser tube replacement and Loop II was isolated for the Loop II outage items. The reactor vessel was depressurized and refueling i floor equipment checked out in preparation for the installation of l

the core region constraint devices.

i 1608 238

.i

- e a e e ~

e 1.0 NARRATIVE

SUMMARY

OF OPERATING EXPERIENCE AND MAJOR SAFETY RELATED MAINTENANCE (continued) 1.3 Testing Instrumented control rod drives in core regions 5 and 35 were calibrated at 60% power. The calibrations were accomplished per RT-486, Part III, by adjusting orifice valves in regions 5 and 35 and moving con-trol rods in regions 15 and 19; The plant remained stable throughout the test, which was completed at 0640 hours0.00741 days <br />0.178 hours <br />0.00106 weeks <br />2.4352e-4 months <br /> on October 25, 1979.

Plant conditions were adjusted to the requirements of RT-500G and fluctuation testing was initiated at 0946 hours0.0109 days <br />0.263 hours <br />0.00156 weeks <br />3.59953e-4 months <br /> on October 25, 1979.

The initial conditions were - reactor power at 62.8%, core resistance at 35.4, and core differential pressure at 1.96 psid. Two unsuc-cessful attempts were made to induce fluctuations by increasing power at 3% per minute from 62.8% to 66.5% and then to 69%. Reactor power was then reduced to 60% and orifice valves were re-adjusted per RT-500G. Reactor power was increased to 64.9% at 3% per minute. Again, the fluctuations did not occur.

Reactor power was reduced to 63%, and a second adjustment of the orifice valves to increase core resistance and core differential pressure was initiated. Ebtion was detected on the data logger trend recorders monitoring differential nuclear channel power approximately 15 minutes af ter operators started adjusting orifice valves. Fluctuations con-tinued for one hour and 45 minutes, and stopped without reducing power.

Fluctuation testing was terminated af ter two unsuccessful attempts were made to reproduce the fluctuations at 63% power.

In the course of reducing reactor power, the following surveillance tests were successfully completed: -

SR 5.2.7a-A, Circulator operability test on water turbine drive.

SR 5.3.2a-A/5.3.3b-A, Main and hot reheat stop check and hot reheat valve full stroke test.

SR 5.4.1.2.3a-M, Circulator LA and 1B trip test.

SR 5.4.1.2.4a-M, Circulator 1C and ID trip test.

1.4 Major Equipment Problems P-4102, circulating water pump uncoupled from motor for testing.

Pump rotates freely; however, motor smoked during test run. Motor bearing clearances were found to be excessive. Bearing clearances were reduced per consultants recommendations. Motor continues to smoke during test runs. General Electric representatives are as-j sisting with further investigation.

l 1608 239 e

1.0 NARRATIVE

SUMMARY

OF OPERATING EXPERIENCE AND MAJOR SAFETY RELATED MAINTENANCE (continued) 1.4 Major Eq,lpment Problems (con tinued)

V-2216 (..oop 1 main steam relief) and V-2245 (Loop II main steam relief) valves continue to leak. Valves will be repaired during scheduled shutdown.

HV-21352, buffer helium dryer valve seat failed twice during this reporting period.

Auxiliary boiler (S-8401) tube repair continues.

Hanger ll-A-H-46890 was declared impaired at 0800 hours0.00926 days <br />0.222 hours <br />0.00132 weeks <br />3.044e-4 months <br /> on October 10, 1979. A change notice was written to effect repair, which was com-pleted 1700 hours0.0197 days <br />0.472 hours <br />0.00281 weeks <br />6.4685e-4 months <br /> on October 12, 1979. The hanger was declared impaired, due to the inability of its anchor bolts to resist the specified torque.

This hanger was discovered during an audit required by Nuclear Regu-latory Commission I & E Bulletin 79-02.

Fuel handling machine functional checks were delayed while technicians resolved computer interface problems. Problems were resolved and the functional checks were successfully completed.

2.0 SINGLE RELEASES OF RADIOACTIVITY OR RADIATION EXPOSURE IN EXCESS OF 10% OF THE ALLOWABLE ANNUAL VALUE None 3.0 INDICATION OF FAILED FUEL RESULTING FROM IRRADIATED FUEL EXAMINATIONS None 4.0 MONTHLY OPERATING DATA REPORT Attached

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1608 240

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1. cnit hame: Fort St. Vrain, Unit No.1
2. Rapor. ins Period: 791001 thru 791031
3. Licensed Bersal Power Osic): 842
4. Nameplate Lating (cross We): 342
5. Design nec=1 cal natins Ciec W ): 330 .
6. Pa^= Dependable capacity (crosa We): 342
7. Nazimun Lependable Capacity Cist We): 330
8. If changes Occur in Capacity la.ings (!tems Nu=her 3 2 rough 7) Sines last Report, cive Raasons yone 1608 241
9. Power Level To Which testricted. If Any (Net We): 231
10. Raamans for sastrictions. If Any: Nuclear Regulatorv Cor::iission restriction (700 cendine resolution of tecroerature fluctuations.
his math Year to Date
  • cumulative *
u. nours in asporting Period 745 2,953 2,953
12. sunner of sours teactor was critical 613.9 2,419.8 2,419.8
13. taneter asserve Shutdown sour 0.0 0.0 0.0
14. sours cenerator on-Line 340.4 982.2 982.2
13. Unit Reserve Shutdown sours 0.0 0.0 0.0
16. cross Bernal Energy cenerated (153) 147,847 476,555 476,555
17. cross nectrical Inergy cenerated Osm) 46,367 140,796 140,796 1s. set rise =ical Energy cenerated Osm) 41,716 123,584 123,584 _
19. enit Service ractor 45.7% 33.3% 33.3%
o. cnic Ava11abilier rector 45.7% 33.3% 33.3%
1. Unit capacity ractor (usins !cc Net) 17.0% 12.7% 12.7%
2. cnic capacity rector (csins : s set) 17.0% 12.7% 12.7%
23. colt rareed oucase aate 44.1% 65.1% 65.1%
24. Shutdowns Scheduled Over Next 6 &nths (*ype, Oate, Maintenance Shutdown Beran October 26
23. If Shut Down at End of Report Period. Estinated Oate DUPLICATE DOCUMENT
26. enics in est status (Prior to commercial operation)

Entire document previously f(Cr f L IsInAL c:mcAurr entered into system under:

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  • Totals CorrtCted to refer to July 1, No. of pages:
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