ML19318C320

Monthly Operating Rept 77 for May 1980

ML19318C320
Person / Time
Site:	Fort Saint Vrain
Issue date:	06/02/1980
From:	Gahm J PUBLIC SERVICE CO. OF COLORADO
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ML19318C319	List: ML19318C318 ML19318C320
References
NUDOCS 8007010346
Download: ML19318C320 (9)

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PUBLIC SERVICE COMPANY OF COLORADO FORT ST. VRAIN NUCLEAR GENERATING STATION MONTHLY OPERATIONS REPORT No. 77 MAY, 1980 3

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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 May,1980,

1. 0 NARRATIVE SUICfARY OF OPERATING EXPERIENCE AND MAJOR SAFETY RELATED MAINTENANCE 1.1 Summary During the period of May 1 to May 21,1980, reactor power varied between 30% and 47% (130 to 145 MWe). From May 21 to June 1,1980, generation was continuous with power output ranging between 150 M7e to 205 MRe.

Generation was curtailed during the reporting period _ due to high primary coolant oxidants along with some plant upsets.

A moisture monitor has been installed on the buffer helium dryer outlet to aid in assessing the primary coolant oxidants. The desicant in both A and B helium dryer tower war also changes as a part of the efforts to bring the oxidant level down. A continuing investigation of the helium circulator auxiliary system is underway to identify other possible prob-lem areas. In the interim, reactor power and core outlet temperatures are being changed to limit operation with core outlet temperatures above 1200*F when the oxidant level is above 10 ppm.

The following is a brief summary of significant events that occurred during tb reporting period.

A plant shutdown occurred on April 28, 1980, as a result of a trip on RIS-93251-ll (high reheat activity) . Investigation revealed -

failed chips in the CS-1A2 logic module.

On April 30, 1980, a plant shutdown occurred as a result of an up-set of A and B bearing water pumps. No specific problem could be identified other than the fact that construction work was being performed in the area of the Loop 1 bearing water surge tank, and that construction activities could have contributed to the upset.

Primary coolant activity was detected at the low pressure r,eparator and in the Reactor Building on May 1,1980. The problem was traced to low buffer helium supply flow to the helium circulators. This resulted in a small amount of primary coolant flow down the shaf t of the helium circu-lacor. There was no release of activity to the atmosphe.re. l l

Preliminary preparations are underway for shipment of spent fuel to l Idaho.

The helium circulator which was removed during the last shutdown was decontaminated and shipped to San Diego on April 29, 1980.

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1.0 NARRATIVE Sli>DLiRY OF OPERATING EXPERIENCE AND >LUOR SAFETY RELATED MAINTE'IANCE (Cont' d) 1.1 Sucmarv (Cont'd)

On >by 13, the J5 feedwater heater was bypassed due to a probable tube leak. Reactor power was decreased to 30% in order to place the emer-gency feedwater header in service, as the normal header had to be iso-lated in order to isolate the #5 feedwater heater. The unit continues to function with the emergency feedwater header supplying the secondary coolant to the steam generator.

On May 15, the backup bearing water header was isolated to repair two safety valves, and P-2105 was put into service to supply bearing water makeup. An oil leak was repaired on the service air compressor.

Also on Iby 15, the helium dryer swapped towers and the low pressure separator ran negative for a short time. This incident may have been the cause for an increase in oxidants to 27 ppm. Oxidants continued to be greater than 10 ppm.

On May 28, 1980, with reactor power at 65% and ther=al generation at 190 MJe, oxidants increased to 12.7 ppm. A pressure valve on the emer-gency feedwater header became unstable and lifted the safety during a backup bearing water accumulator surveillance test. At this time, a leak became apparent on the Loop 2 steam generator interspace. Further investigation and testing is underway to evaluate leakage sources and paths, as well as quantifying the leak rate.

Oxidants continued to increase until the purification trains were swapped on May 30, and the system 21 bearing water surge tanks were flushad to improve water chemistry.

1.2 Operations On May 1,1980,1B circulator tripped on loss of bearing water due to an upset caused by changing the bearing water y-strainers. The 1B circulator was returned to service, the main turbine generator was synchronized, and power was increased to 52%. Primary coolant oxidants then increased above 15 ppm and reactor power was reduced to 45% and 130 MRe, with average region outlet temperature less than 1200*F.

Radioactivity was detected in the low pressure separator with the source of the activity being 1D circulator buffer return flow, which was adjusted to correct the problem. During this incident, activity was also detected in the Reactor Building, the source of which was valve packing leaks on the buffer helium dryer. This leakage has been stopped. .

The plant continued to operate between 45% and 53% over the next seven days with power level dictated by primary coolant oxidant levels. On E.

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May 7,1980, the pelton supply to the Loop 2 circulators was isolated to repair a steam leak on the pressure control valve piping. Plant con-ditions on May 8 were as follows; 46% power,135 M7e, primary coolant i

1.0 NARRATIVE

SUMMARY

OF OPERATING EXPERIENCE AND MAJOR SAFETY RELATED MAINTENANCE (Cont'd) 1.2 Operations (Cont'd) oxidants greater than 10 ppm, average-region outlet temperature less than 1200*F. As little progress was being made to reduce total primary coolant oxidants by the purification system, it was decided to change-out the helium dryer desicant and observe what effect, if any, this change would have on total primary coolant oxidants. No definite change was observed. Operation continued to be limited by primary coolant

. oxidants being greater than 10 ppm through May 13, 1980. .

On May 13, 1980, #5 feedwater heater developed a tube leak. The secon- '

dary coolant flow path was changed to the emergency feedwater header.

Operation has continued in this manner through the re=ainder of this report period.

On May 15, 1980, the backup bearing water header was isolated in order to repair the backup bearing water safety valves. Reactor power was at approximately or equal to 50% and 130 MWe, and continued at that level until May 24. At that time, total primary coolant oxidants were 7.5 ppm and power was raised from 50% to 67% over a period of the next three days. Operation continued at approximately or equal to 200 MWe for the remainder of this report period.

Spent fuel shipping preparation has started with actual off-site ship-ment which started on May 28, 1980.

The helium circulator, which was removed during the last shutdown, was examined by General Atomic Company at San Diego, California, and con-firmed to have a broken shaft seal bellows.

1.3 Testing Operations conducted 114 tests during this report period.

2.0 SINGLE RELEASES OF RADIOACTIVITY OR RADIATION EXPOSURE IN EXCESS OF 10%

OF THE ALLOWABLE ANNUAL VALLT None 3.0 INDICATION OF FAILED FUEL RESULTING FROM IRRADIATED FUELS NhiINATIONS None 4.0 MONTHLY OPERATING DATA REPORT Attached I

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cerunNc DAM REPORT ' DOCK T No. 50-267 OAu 800602 CCMPt. nD sT J. W. Cahm utzrnosz (303) 785-2253 CP!?ATINc STAT'*5

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1.  : nit sane: Fort St. Vrain .

2. Reportins Period: 800501 through 800531

3. Licensed Thermal Pcwer Osit): 842

4. Naneplate Racing (Cross We): 342

3. Design Ilectrical Racing Ciec :Sie): 330

6. Ida

• um Dependable Capacity (Cross We): 342

7. Maximus :ependahls capacity Otet We): 330 S. If Changes occur in Capacity Racings (Items Number 3 Through 7) Since Last Report, Give Raasons:

None

9. Fever Level To 'Jhich Restricted, If Any (Net We): 231

10. Reasons for Restrictions, If Any: Nuclear Regulator'r Commission restrict 4n 79T nondine resolution of temperature fluctuations. -

This Month Tsat to Date Cwmalative 744 3,647 8,064

11. Hours in Raporting Period 1:. summer of sours Reactor was critical 744.0 2,304.9 4,837.7 0.0 0.0 0.0

13. Reactor Reserve Shutdown sours 737.6 1,646.9 2,629.1

14. sours cenerator on-tine 0.0 0.0 0.0

13. Unic Reserve Shutdown Hours

16. cross Ther=al Enerz- cenerated (1sia) 318,452 725.063 1,203,018

17. Gross Ilectrical Energy Generated Oste) 108,245 237.023 377,819 102,377 220.013 343,597

13. set riectrical Energy cenerated ossa) 99.1% 45.2% 32.6%

19. enit Service rector

o. cnic Availability ractor 99.1% 45.2% 32.6%

1. tait capacity raccor (Using xDC Net) 41.7% 18.3% 12.9%

. Unit capacity ractor (Usins :Ex Net) 41.7% 18.3% 12.9%

0.9% 21.7% 46.5%

23. enit rurced oucas sat.

24 Shutdowns Scheduled over Next 6 Months (Type, Date, and Duration of Each): N/A

13. If Shut Down at End of Report Period, Istimated ace of Startup: N/A

25. Units In Test Status (Frior to Commateial operation): Forecast Achieved INInAL CRInCALITT N/A WA INIC AL ILICIRICITT N/A N/A

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AVERAGE DAILY UNIT POWER LEVEL Docket No. 50-267 Unit Fort StI Vrain Date 800602 -

Cc:::pleted By J. E. Gahm

-Telephone (303) 785-2253 Month Mav. 1980 DAY AVERAGE DAILY POWER LEVEL DAY AVERAGE DAILY POWER LEVEL (MWe-Net) (MWe-Net) 1 95 17 125 2 123 18 125 3 121 19 124 ,

4 131 20 124 5 123 21 134 6 137 22 136 7 131 23 138 8 129 24 146 9 133 25 161 10 135 26 174  !

11 133 27 183 12 133 28 184 13 125 29 .

186 14 124 30 158 15 124 31 145 16 125

• Generator on line but no net generation.

REFUELING INFORMATION

1. Name of Facilitv. Fort St. Vrain, Unit No. 1

2. Scheduled date for next refueling shutdown. June, 1, 1981 -

3. Scheduled date for restart following refueling. September 1, 1981

4. Will refueling or resumption of operation thereafter require a technical specification change +

or other license amendment? No If answer is yes, what, in general, will these be?

If answer is no, has the reload The Plant Operations Review Committee will fuel design and core configura- review any questions associated with the tion been reviewed by your Plant core reload.

Safety Review Committee to deter-mine whether any unreviewed safety questions are associated with the core reload (Reference 10CFR Section 50.59)?

If no such review has taken olace, when is it scheduled? January 1, 1981

5. Scheduled date(s) for submitting ---------------

proposed licensing action and sunporting information.

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6. Important licensing considera- ----

tions associated with refueling, e.g., new or differene fuel de-sign or supplier, unreviewed design or performance analysis methods, significant changes in fuel design, new operating pro-cedures.

7. The number of fuel assemblies a) 1482 HTGR fuel ele =ents (a) in the core and (b) in the spent fuel storage pool. b) 238 spent RTGR fuel elements

8. The present licensed. spent fuel Capacity is limited in size to about one-pool storage capacity and the third of core (approxi=ately 500 HIGR ele-size of any increase in licensed ments). No change is planned.

l storage capacity that has been I requested or is planned, in number of fuel assemblies.

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REFUELING INFORMATION (CONTINUED)

9. The projected date of the 1906 under the Three Party Agreement (Con-last refueling that can be tract AT (04-3)-633) between DOE, Public discharged to the spent fuel Service Company of Colorado (PSCo), and pool assuming the present . General Atomic Company.*

licensed capacity.

• The 1986 date is based on the understanding that spent fuel discharged during the term of the Three Party Agreement will be shipped to the Idaho National Engineering Laboratory for storage by DOE at the Idaho Chemical Processing Plant (ICPP) . The storage capacity has evidently been sized to accomodate fuel which is expected to be discharged during the eight year period covered by the Three Party Agreement.

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