05000267/LER-1981-015, Forwards LER 81-015/03L-0.Detailed Event Analysis Encl

Forwards LER 81-015/03L-0.Detailed Event Analysis Encl

ML19347D235
Person / Time
Site:	Fort Saint Vrain
Issue date:	03/06/1981
From:	Warembourg D PUBLIC SERVICE CO. OF COLORADO
To:	Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
Shared Package
ML19347D236	List: 05000267/LER-1981-015, Forwards LER 81-015/03L-0.Detailed Event Analysis Encl 05000267/LER-1981-015-03, /03L-0:on 810204-0220,plant Operated in Degraded Mode on Nine Occasions.Causes Include Increased Oxidant Outgassing After Power Increase & Moisture Introduced Into Primary Coolant as Part of Approved Test
References
P-81087, NUDOCS 8103110524
Download: ML19347D235 (1)

LER-1981-015, Forwards LER 81-015/03L-0.Detailed Event Analysis Encl

Event date:
Report date:
2671981015R00 - NRC Website

text

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l puhuc Service Company cf OcHersde 16805 ROAD 19%

. _ L.i PLATTEVILLE, COLOR ADO 80651 March 6, 1981 Fort St. Vrain Unit No. 1 P,81087 Mr. Karl V. Seyfrit, Director Nuclear Regulatory Commission Region IV Office of Inspection and Enforcecent 611 Ryan Plaza Drive Suite 1000 Arlington, Texas 76012 Reference: Facility Operating License No. DPR-34 Docket No. 50-267

Dear Mr. Seyfrit:

Enclosed please find a copy of Reportable Occurrence Report No. 50-267/

81-015, Final, submitted per the requirenents of Technical Specification AC 7.5.2(b)2.

Also, please find enclosed one copy of the Licensee Event Report for Reportable Occurrence Report No. 50-267/81-015.

Very truly yours, h

f7n Don Warembourg Manager, Nuclear Production

- DW/cis Enclosure cc: Director, MIPC F "'onea4

REPORT DATE:

'" arch 6, 1981 REPORTA3LE CCCURRENCE 81-015 ISSUE O OCCURRENCE DATE:

Februarv 4, 1981 Page 1 of 8 FORT ST. VRAIN NUCLEAR GENERATING STATION PUBLIC SERVICE CO:f AW OF COLOPADO 16805 WELD COUNTl ROAD 19 1/2 PLATIEVILLE, COLCRADO 80651 REPORT NC. 50-267/81-015/03-L-0 Final IDENTIFICATION OF OCCURRENCE:

During the period from February 4,1981, to February 20, 1981, the plant was operated in a degraded mode of LCO 4.2.10 on nine occasions.

These e' rents are reportable per Fort St. Vrain Technical Specification AC 7.5.2(b) 2.

EVENT

DESCRIPTION

Event 1 (See Figure 1) At about 0400 hours0.00463 days <br />0.111 hours <br />6.613757e-4 weeks <br />1.522e-4 months <br /> on February 4, 1981, while the average core outlet temperature was above 1200*F, the primary coolant total oxidants increased above 10 PPMV, The oxidants remained above 10 ??MV until about 0900 hours0.0104 days <br />0.25 hours <br />0.00149 weeks <br />3.4245e-4 months <br /> on February 4,1981. This event cons titutes operation in a de-graded mode of LC0 4.2.10.

Event 2 (See Figure 1) At about 2200 hours0.0255 days <br />0.611 hours <br />0.00364 weeks <br />8.371e-4 months <br /> on February 4,1981, while the aversge core outlet te=perature was above 1200*F, the total primarf coolant oxidants increased above 10 PPMV. The oxidants remained above 10 ??MV until about 0530 hours0.00613 days <br />0.147 hours <br />8.763227e-4 weeks <br />2.01665e-4 months <br /> on February 5,1981. This event constitutes operation in a de-graded mode of LCO 4.2.10.

Event 3 (See Figure 1) At about 2000 hours0.0231 days <br />0.556 hours <br />0.00331 weeks <br />7.61e-4 months <br /> on February 6,1981, while the average core outlet te=perature was above 1200*F, the total primary coolant oxidants increased above 10 ??MV. The oxidant _: remained above 10 PPMV until about 2300 hours0.0266 days <br />0.639 hours <br />0.0038 weeks <br />8.7515e-4 months <br /> on February 8,1981. This event constitutes operation in a de-graded mode of LCO 4.2.10.

REPORTABLE OCCt:RRENCE 31-015 ISSUE O Page 2 of 8 EVENT

DESCRIPTION

(Cont' d)

Event 4 (See Figure 2) At about 1300 hours0.015 days <br />0.361 hours <br />0.00215 weeks <br />4.9465e-4 months <br /> on February 10, 1981, while the average core outlet temperature was above 1200*F, the pri=ary coolant total oxidants increased above 10 PPMV. The oxidants remained above 10 PPMV until about 1400 hcurs on February 14, 1981. This event constitutes operation in a de-graded mode of LCO 4.2.10.

Event 5 (See Figure 2) At about 0100 hours0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br /> on February 15, 1981, while the average core outlet temperature was above 1200*F, the pri=ary coolant total oxidants increased above 10 PPMV. The oxidants remained above 10 PPMV until about 0800 hours0.00926 days <br />0.222 hours <br />0.00132 weeks <br />3.044e-4 months <br /> on February 15, 1981. This event constitutes operation in a de-graded mode of LCO 4.2.10.

Events 6 and 7 a

(See Figure 2) On February 15, 1981, at about 1530 hours0.0177 days <br />0.425 hours <br />0.00253 weeks <br />5.82165e-4 months <br /> and again at about 1930 hours0.0223 days <br />0.536 hours <br />0.00319 weeks <br />7.34365e-4 months <br />, the primary coolant oxidants increased above 10 PPMV for about one hour each time. The average core outlet temperature was above 1200*F on both occasions. These events constitute operation in a degraded = ode of LCO 4.2.10.

Event 8 (See Figures 2 and 3) At about 1500 hours0.0174 days <br />0.417 hours <br />0.00248 weeks <br />5.7075e-4 months <br /> on February 16, 1981, while the average core outlet temperature was above 1200*F, the primary coolant total oxidants increased above 10 PPMV. The oxidants remained above 10 PPXV until about 2300 hours0.0266 days <br />0.639 hours <br />0.0038 weeks <br />8.7515e-4 months <br /> on February 18, 1981. This event constitutes operation in a degraded mode of LCO 4.2.10.

- Event 9 (See Figure 3) At about 0200 hours0.00231 days <br />0.0556 hours <br />3.306878e-4 weeks <br />7.61e-5 months <br /> on February 21, 1981, while average core

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outlet temperature was above 1200'F, the primary coolant total oxidants in-creased above 10 PPMV. The oxidants remained above 10 PPMV, except for short periods of time, until 1500 hours0.0174 days <br />0.417 hours <br />0.00248 weeks <br />5.7075e-4 months <br /> on February 23, 1981. This eveet constf-cutes operation in a degraded mode of LCO 4.2.10.

REPORTABLE OCCL*RRENCE 81-016 ISSUE O Page 3 of 8

CAUSE

DESCRIPTION:

Event 1

. The reactor power was increased from 60% to 65% at about 2230 hours0.0258 days <br />0.619 hours <br />0.00369 weeks <br />8.48515e-4 months <br /> on Febru-a ry 3, 1981. At this time, the average core outlet temperature increased from about 1235'? to about 1310*F, resulcing in oxidant out-gassing from the core graphite which peaked at about 0600 hours0.00694 days <br />0.167 hours <br />9.920635e-4 weeks <br />2.283e-4 months <br /> on February 4,1981.

Event 2 No specific cause can be associated with this event.

Event 3 During the period prior to and during this event, moisture was intentionally introduced into the primary coolant during scheduled tests of the dewpoint moisture monitor response times.

Event 4 At 0828 hours0.00958 days <br />0.23 hours <br />0.00137 weeks <br />3.15054e-4 months <br /> on February 10, 1981, during scheduled testing of the plant protective system, a spurious trip of both helium circulators in Loop 1 oc-curred. Either the circulator trip or the recovery process resulted in a moisture ingress which caused the very rapid increase in primary coolant oxidants.

Event 5 No ' specific cause can be associated with this event.

Event-6 No specific cause can be associac2d with-this event.

. Event 7

- No specific' cause can be associated with this avent.

. Even t 8 No' specific cause can be associated with this event.

Event 9-During the period prior to and ddting this event, moisture was intentionally introduced into the primaly.ccolant during scheduled tests 'of the dewpoint moisture monitor response time.

REPORTABLE OCCL"A.RENCE 81-015 ISSUE O Page 4 of S CORRECTIVE ACTION:

The corrective action for all events of operation in a degraded mode of LCO 4.2.10 during the period was to allow the pri=ary coolant purification system to remove the primary coolant oxidants and thereby, bring them below the 10 PPMV limit of the LCO. During event #4, the reactor power level was redaced to lower average core outlet ce=perature and increase the water /

graphite reaction race.

No further corrective action is anticipated or requir?.d for the nine events contained in this report, s

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REPORTABLE OCCL*RRENCE S1-015 ISStlE O Page 8 of 8 Prepared By:

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AL Richard R. Fros:

Technical Services Supervisor Reviewed By:

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.echnical Services Supervisor Reviewed By:

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Frank M. Mathie Operations Manager Approved By:

h MM Don '4arembourg Manager, Nuclear Production f.~m.,_