ML19321A505

Forwards LER 80-033/03L-0

ML19321A505
Person / Time
Site:	Fort Saint Vrain
Issue date:	07/18/1980
From:	Warembourg D PUBLIC SERVICE CO. OF COLORADO
To:	Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
Shared Package
ML19321A506	List: ML19321A505 ML19321A508
References
P-80219, NUDOCS 8007230534
Download: ML19321A505 (5)

Text

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, bs public service company e conomde 16805 ROAD 19%

PLATTEVILLE, COLOR ADO 80651 July 13, 1980 Fort St. Vrain Unit No. 1 P-80219 Mr. Karl V. Seyfrit, Director Nuclear Regulatory Coc: mission Region IV Office of Inspection and Enforcement 611 Ryan Plaza Drive Suite 1000 Arlington, Texas 76012

Reference:

Facility Operating License No. DPR-34 Docket No. 50-267

Dear Mr. Seyfrit:

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

80-33, Final, sub=itted per the require =ents 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. 50-267/80-33.

Very truly yours, l

[W M Don Ware = bourg /

4 Manager, Nuclear Production DW/cis -

Enclosure cc: Director, MIPC V

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8007230

REPORT DATE: July 18, 1980 REPORTABLE OCCURRENCE 80-33 ISSUE O OCCURPJdCE DATE: June 20. 1980 Page 1 of 4 FORT ST. VRAIN NUCLEAR GENERATING STATION PUBLIC SERVICE COMPANY OF COLORADO 16805 WELD COUNTY ROAD 191/2 PLATTEVILLE, COLORADO 80651 REPORT NO. 50-267/80-33/03-L-0 Final IDENTIFICATION OF OCCURRENCE:

On June 20, and again on June 30, 1980, with the reactor operating at power, reactor dewpoint exceeded the limits of LCO 4.2.11, Figure 4.2.11-1.

This constitutes operation in a degraded mode of LCO 4.2.11 and is reportable per Fort St. Vrain Technical Specification AC 7.5.2(b)2.

EVENT DESCRIPTION:

Operation in a degraded mode of LCO 4.2.11 occurred on two occasions between June 20 and 30, 1980, as described below:

Event #1 On June 19, 1980, reactor power was being increased following recovery from a loop shutdown and turbine trip on June 17. Reactor power had been raised ,

to approximately 25% in preparation for placing the turbine-generator on  !

line.

At 2300 hours0.0266 days <br />0.639 hours <br />0.0038 weeks <br />8.7515e-4 months <br /> on June 19, problems were observed with 1A helium circulator buffer-mid-buffer indication. Shortly thereafter, an increase in primary ,

coolant moisture was observed. The 1A helium circulator tripped at 2340 hours0.0271 days <br />0.65 hours <br />0.00387 weeks <br />8.9037e-4 months <br /> l due to high buffer-mid-buffer differential pressure. .j i

At 0000 hours0 days <br />0 hours <br />0 weeks <br />0 months <br /> on June 20, 1980, the primary coolant moisture log reactor dewpoint readi..g, as indicated by ME-9307, was outside the . limits of LCO 4.2.11, Figure 4. 2.11-1. Refer to Table I for a comparison of allowable and actual reactor dewpoints during this occurrence.

The maximum reactor dewpoint occurred at 0000 hours0 days <br />0 hours <br />0 weeks <br />0 months <br /> on June 20, 1980, and reactor dewpoint decreased over the next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. by 1400 hours0.0162 days <br />0.389 hours <br />0.00231 weeks <br />5.327e-4 months <br /> on June 20,

• decrease in reactor power had reduced average core outlet temperature to a  !

point where reactor dewpoint was within the acceptable 11=1ts of Figure 4.2.11-1.

REPORTABLE OCCURRENCE 80-33 ISSUE O Page 2 of 4 EVENT DESCRIP1.Oli: (Cont'd)

Event #2 Following the reactor power decrease of June 20, 1980, reactor dewpoint remained within the acceptable limits of LCO 4.2.11, Figure 4.2.11-1, until June 30, 1980. On June 30, reactor power was increased in preparation for placing the turbine generator on line.

At 0600 hours0.00694 days <br />0.167 hours <br />9.920635e-4 weeks <br />2.283e-4 months <br /> on June 30, reactor dewpoint was in the " Limited Accep table" Area of LCO 4.2.11,- Figure 4.2.11-1, due to the relatively high primary coolant moisture content. By 1200 hours0.0139 days <br />0.333 hours <br />0.00198 weeks <br />4.566e-4 months <br /> on June 30, reactor power and average core outlet temperature had increased sufficiently that the 1200 and 1400 hour0.0162 days <br />0.389 hours <br />0.00231 weeks <br />5.327e-4 months <br /> reactor dewpoints were outside the linics of Figure 4.2.11-1.

At 1540 hours0.0178 days <br />0.428 hours <br />0.00255 weeks <br />5.8597e-4 months <br />, a decision was made to decrease load in order to re-establish compliance with LCO 4.2.11. By 1600 hours0.0185 days <br />0.444 hours <br />0.00265 weeks <br />6.088e-4 months <br />, reactor dewpoint (although still

" Limited Acceptable") was no longer outside the curve of Figure 4.2.11-1.

Refer to Table II for a comparison of allowable and actual reactor dewpoints during this occurrence.

CAUSE DESCRIPTION:

Event #1 The increase in primary coolant moisture content and reactor dewpoint of June 20 is being attributed to a moisture ingress which occurred during the LA circulator buffer-mid-buffer upset and subsequent circulator trip.

Event #2 Increase in reactor dewpoint for the June 30 event is attributable to the residual moisture from the June 19 ingress.

CORRECTIVE ACTION:

Reactor power reduction and corresponding decrease in average core outlet tenperature resulted in plant operation with reactor dewpoint inside the curve of Figure 4.2.11-1 by 1400 hours0.0162 days <br />0.389 hours <br />0.00231 weeks <br />5.327e-4 months <br /> on June 20 (Event #1) and by 1600 hours0.0185 days <br />0.444 hours <br />0.00265 weeks <br />6.088e-4 months <br /> on June 30 (Event #2).

No further corrective action is anticipated or required. '

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l REPORTABLE OCCURRENCE 80-33 ISSUE O Page 3 of 4 TABLE I Core Outlet Allowable Actual Time Temperature (*F) Reactor Dewpoint (*F) Reactor Dewpoint (*F) 2200* 1122 -9 -21 0000 1142 -12 +60 0200 1159' -15 +47 0400 1134 -11 +36 0600 1154 -14 +29 0800 1159 -15 +22 1000 1158 -15 +17 1200 1140 -12 +15 1400** 876 M7 +14

• June 19,1980 (other times, June 20)

• • Compliance with LCO 4.2.11 TABLE II i

Core Outlet  ! Allowable Ac tual Time

• l Temperature (*F) l Reactor Dewpoint ('F)

Reactor Dewpoint (*F)

I I

1000 1 1131 -11 -20

! i 1200- i 1178 -18 -17 l

1400 t

1184 i

-18 e -17 ] l 1600 I' 1136 I -12 -14 1

• All times are for June 30, 1980 I

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REPORTABLE OCCURRENCE 80-33 ISSUE O Pa g- 4 o f 4

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Prepared By: [

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C. ,hs.vMu a Cathy C illirsch Technical Services Technician Reviewed By: / /],  !

/. We Gahm J/ Technical Services Supervisor Reviewed By:

Trank M. Mathie Operations Manager Approved By:  ;(( 7Va.umM _

Don Warembourg /

Manager, Nuclear Production l

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