ML20032C969

Monthly Operating Rept for Oct 1981

ML20032C969
Person / Time
Site:	Fort Saint Vrain
Issue date:	11/01/1981
From:	Mcbride L PUBLIC SERVICE CO. OF COLORADO
To:
Shared Package
ML20032C964	List: ML20032C963 ML20032C969
References
NUDOCS 8111130262
Download: ML20032C969 (10)

Text

-

i r

PUBLIC SERVICE COMPANY OF COLORADO FORT ST. VRAIN NUCLEAR GENERATING STATION MONTHLY OPERATIONS REPORT i

NO. 94 October, 1981 l

5 3 u.pe oF SI I I I 362(o2-

. 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, 1981.

1.0 NARRATIVE

SUMMARY

OF OPERATING EXPERIENCE AND MAJOR SAFETY RELATED MAINTENANCE 1.1 Summary The plant was operating at 70% power at the beginning of the month. The feedwater flow path was transferred from the normal to emergency header on October 5 to allow maintenance of the feedwater heaters.

Feedwater leakage within heaters #5 and #6 would have prevented reaching 100%

power.

The power was reduced to 35% on October 9, to remove "B" boiler feedpump from service. Leaky discharge valves on this pump were delaying maintenance on the feedwater heaters because the heaters would not drain or cool acequately.

The heater #6 repairs were completed on October 19, and heater #5 was temporarily bypassed, as neccessary repairs could not be affected.

The reactor power was reduced to 2% on October 14 to allow -

taking the loops sequentially out of service to repair TCV-5207 and 5208. These main steam desuperheater valves also needed to be repaired prior to 100% power operation.

The piant was restarted, and the rise-to power testing under RT-500K began on October 21.

The power had been increased to 67% when a circulator spe2d instrument failed and caused a Loop 2 shutdown. The loop was recovered, and the unit was operating at 74% on October 24, continuing our power escalation under RT-500K.

A leak on the B-2-3 steam generator moc'ule re-appeared on October 26. This leak caused excessive helium loss into the cold reheat header and created a serious problem maintaining condenser vacuum.

An agreement was subsequently reached with the Nuclear Regulatory Commission that allowed operating this particular steam generator module with an interspace pressure slightly above cold i

reheat steam pressuee.

This significantly reduced the helium loss.

The modification necessary to operate the B-2-3 module in this manner should be completed by November 2.

3 m.

r.' 1.2 Ooerations The plant was operating at 70% power and 230 MW at the beginning of the month.

An evaluation was in progress concerning the excessive feedwater flow demand generated by the leak in.the #5 and #6 feedwater heaters.

It was decided that it would be impossible to operate the plant at 100% power with the feedwater heater leaks.

Therefore, feedwater. flow was transferred to the emergency feedwater headers on October 5.

This allowed clearing out these heaters for maintenance.

"C" boiler feedpump was also taken out of service because of. previous problems.with leaking discharge valves.

The plant operated on the emergency feedwater header until October 8.

The Loop 2 main steam desuperheater valve (TCV-5208) failed open at 0415 hours0.0048 days <br />0.115 hours <br />6.861772e-4 weeks <br />1.579075e-4 months <br /> when the~ air supply line broke. The sudden decrease in reheat steam pressure caused both "A"

and "0" circulators to trip on speed and feedwater mismatch. The power was reduced to 30% to return these circulators to service, and-the plant was at 70%

again at'1400 hours0.0162 days <br />0.389 hours <br />0.00231 weeks <br />5.327e-4 months <br />.

The power was reduced to 35% (100 MWe) on October 9 to remove "B" boiler feedpump from service. The normal header discharge valves on the "B" pump were leaking sufficiently to prevent work on the fifth and sixth feedwater heaters.

Removal of "B"

boiler feedpump from service allowed maintenance personnel to enter the heaters to begin the evaluation / repair.

A hydraulic seal problem was discovered on the "A"

circulator steam turbine speed valve (SV-2105) on October 10.

The power was reduced from 35% to 30% so the circulator could be taken off and maintenance on the valve performed.

Investigations into the feedwater heater revealed extensive damage to the tube sheet on the #5 heater.

The only practical solution was to cap the lines to the heater so operation could resume on the normal feedwater header. The feedwater bypass valves and outlet isolation valves n re also found to have excessive leakage and extensive o m ge to the inlet bypass valve. The #6 heater was found to nave several leaks that required pluggir.g five tubes.

The main steam desuperheater temperature control valves (TCV-5207 and 5208) were determined to have excessive

-leakage that could jeopardize plant operation during the testing to 100% power. The reactor was brous't to 2% power l

. on October 14 to repair these valves. The valve repairs were completed on October 15, and the turbine generator was synchronized on October 16 at 0458 hours0.0053 days <br />0.127 hours <br />7.572751e-4 weeks <br />1.74269e-4 months <br />. The power was then increased to about 38% and held because of the flow limitation of operating with only one boiler feedpump.

The repairs were completed on the feedwater heaters on October 19. A reactor scram on two loop trouble, due to low fixed feedwater flow trips on all four circulators, was received at 1725 hours0.02 days <br />0.479 hours <br />0.00285 weeks <br />6.563625e-4 months <br />. This occurred when the reactor power was being reduced to return the normal feedwater header to service. The plant was subsequently restarted, and the turbine generator synchronized at 1525 hours0.0177 days <br />0.424 hours <br />0.00252 weeks <br />5.802625e-4 months <br /> on October 20.

The plant was stabilized at 40% at 1000 hours0.0116 days <br />0.278 hours <br />0.00165 weeks <br />3.805e-4 months <br /> on October 21, and we began data gathering for RT-500K, the rise-to power test.

The power was increased per the test requirements to 67% on October 22. However, a circulator speed instrument failed at 1306 hours0.0151 days <br />0.363 hours <br />0.00216 weeks <br />4.96933e-4 months <br /> and this caused a loop shutdown when the Loop 2 circulators tripped on speed / flow mismatch. The failed speed instrument provides a signal for Loop 1 water turbine speed instruments and Loop 2 steam turbine speed instruments.

The power was reduced to 2% to recover Loop 2, and the turbine was again synchronized at 0715 hours0.00828 days <br />0.199 hours <br />0.00118 weeks <br />2.720575e-4 months <br /> on October 23.

The reactor power was increased to 74% on October 24, during RT-500K testing. A previous problem of excessive helium leakage on the B-2-3 steam generator module re-appeared on October 26. The leak rate was determined to exceed the 700 pounds per day limit, which was authorized by the Nuclear Regulatory Commission during our previous experience with this problem.

Attempts to decrease the leak rate to less than the maximum allowable included adjusting the power and reheat steam temperatures. All attempts to decrease the leak failed.

The reactor power L

was reduced to 5% on October 25, where the leak stabilized at less than the maximum allowable.

l A temporary solution to the B-2-3 leakage problem was agreed upon on October 26. The fix included segregating the B-2-3 penetration piping from the remainder of the Loop 2 steam generators' modules and installing a separate rupture disk and safety valve. Although this modification i

is temporary in nature, it was necessary to meet the Technical Specification penetration interspace protection criteria.

An agreement with the Nuclear Regulatory 3

Commission was then reached that allowed us to operate the B-2-3 module at slightly above cold reheat steam pressure i

r

~

. rather than the usual requirement of being above primary coolant pressure.

This significantly decreased the available differential pressure causing the leak.

The B-2-3 modifications were nearly completed at the end of the month, and startup is now expected to be about November 2.

2.0 SINGLE RELEASES OF RADI0 ACTIVITY 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 MONTHIJ_0PERATING DATA REPORT Attacheo l

3

CF! EATING DA3 RZPORT DOCKET NO.

50-267 DATE 811101 COMPL CED BT l.

M.

Mr* h-4 A a TELzPnost (303) 785-2224 i

CPERATING STATUS Notts 1.

Onit same:

Fort St. Vrain 2.

Reportins Period:

811001 throuah 811031 3.

Licensed thermal Power cert):

842 4.

sameplate nating (. Gross W e):

342 5.

Destan Electrical Rating Clet 29fe):

110 6.

• wt.= Dependable Capacity (Gross We): 342 7.

• v4==

Dependable capacity Clet We):

110 3.

If Changes occur in Capacity Eatings (Items Number 3 Through 7) Since Last Report, Civs Reasons:

Ncna 9.

Power Level To nich Eastricted, If Any (Net 19fe):

231

10. naasons for Restric sons, If Any:

NRC restrictf.on of 70% pending resolution of temperature fluctuations.

This Month Year to Data h aative 745 7.296 20.497

11. sours in asportins Period

12. sumber of sours anactor was Critical 739.6 5.234.2 14.169.4 0.0 0.0 0.0

u. anactor Reserve shutdown sours 14.

sours Cenerator on-Line 490.7 4.079.5 9.772.8

u. enic anserve shutdown sours 0.0 0.0 0.0

16. Gross :hormal Energy Generated (W e) 223.487.6 2.128.025.6 4.836.118.4

17. Gross Electrical Energy Generated Osra) 7R.684 7R1.991

1. Ass.Ags

15. Net Electrical Energy Generated (W E) 72.051 723.258 1.5??.559 65.9 55.9 47.7

19. Unit service ractor f

.o.

rait Availability ractor 65.9 55.9 47.7

21. Onit Capacity Factor (Using !!DC Net) 29.3 30.0 22.5 f

22. Omic capacity Factor (Using DE13et) 29.3 30.0 22.5

23. Unic Forced Outage aate 34.I 29.8 14.7 f

l Maintenance /

24.

Shutdowns Scheduled Over Next 6 ! baths (Type, Date, and Duration of Each):

l modification shutdown November 30, 1981, through Januarv, 1982.

25. If Shut Down at End of asport Period. Estimated Date of Startups I

26.

Cnits In Test Status (Prior to Commercial Operation):

Forecast Achieved f

l INITIAL CRITICAL IT N/A N/A l

N/A N/A INITIAL ELECnICITT N/A N/A c::eERCIAL CPERA!!CN l

l l.

-.... 1

_. __ _ Z ~ _. _. _ _.. _,_.

i unit suunxwNs au _rwER REnociuNs 50-267 pocuRT No.

Fort St. Vrain unit NAME 811101 3

narg L. M. McBride c(Net.ETEo sT REr0RT HUNTH October, 1981 Tst.ErNoNE (303) 785-2224 S

HEDR)0 OF SNUTTING IMMN SYSTEM c00G'UNENT No.

DATE TYRE DURATION REASON REACTOR 1.ER f CODE 0)DE CAUSE AND CORRECTIVE ACTION 10 rREVENT REX:URRE30CE

$1-021 811013 F

55.1 B

4 N/A HHD llTEXCH Heater f5 tube leakage, taken out of system for repair / replacement.

Reactor remained at <2.0% thermal power.81-022 811019 F

22.0 11 3

N/A IBil XXXXXX 2-loop trouble, reactor scram, turbine trip. PPS protection.

B 1-02'J 811022 F

18.7 11 4

N/A IBil XXXXXX Loop 2 shutdown due to electronic oscillator malfunction. PPS protection.81-024 811025 F

158.5 11 4

81-068/03L-0 CJA PENETR Steam generator B.2.3 penetration leakage of helium.

I Plan to complete fluctuation testing program in November, 1981.

AVERAGE DAILY UNIT POWER LEVEL Docket No.

50-267 Unic Fort St. Vrain Date 811101 Completed By L. M. McBride Telephone (303) 785-2224

& nth

-October, 1981 DAY AVERAGE DAILY POWER L57. EL DAY AVERAGE DAILY POWER LEVEL (MWe-Net)

(MWe-Net) 1 211.4 17 107.1 2

220.7 18 90.0 3

215.9 19 71.7 4

218.8 20 21.9 5

205.6 21 121.8 6

211.3 22 92.8 7

216.3 23 105.1 8

167.0 24 178.5 9

154.9 25 29.6 10 86.1 26 0.0 11 84.9 27 0.0 12 90.5 28 0.0 13 81.3 29 0.0 14 0.0 30 0.0 l

15 0.0 31 0.0 16 70.0 l

l

• Generator on line but no ' net generation,

RDT1!I,3C UFC10M' ION i

I.

Name of 7ac1110r.

Fort St. Vrsin Uni No. 1 2.

Scheduled data for nex: refueling shutdown.

Ocrober 1, 1983 3.

Scheduled data for restart following esfueling.

c.-.-.ber 1.

1o93 4.

Will :sfueling or :ssumption of operacion zereaf:ar : squire 4 J

=ew " t specification change or other license===rw%=nc?

Yes If answer is yes, vbat, in teneral, vill these be?

Use of type H-451 graphite.

I* answer is on, has the reload fuel design and cara configura-

1on been reviewed by your Plant Safety Review Commit:aa to decar-mine whether any unrev m ed d

safscy quest.cas are assoc 1:.:ad wi:h the cara reload (2aferenes 10C71 Sec 'on 50.391?

If on such reviar has takaa elace, when is 1: scheduled?

3.

Scheduled data (s) for subsid ing proposed licensing ac:1on and suncer dne information.

Not scheduled at this time: to be deter:nined.

s l

6.

Important licensing ex.sidera-cions associa:ad w1:h==i'"=1 Ng, e.g., new or d***eranc fuel de-sign or suppliar, unreviewed design or performance analysis machods, significanc changes in fuel design, new operacing pro-endurss.

7.

The number of fral assemblies 1482 CGR fuel elements (a) in the cars and (b) in I

t,e scent,.ual storage col.

230 spenc EIGR fuel elements 3.

The present licensed spent fuel pool storage capac.1:7 and the Capacity is 11=1:ad in size to about one-si:e of any incrassa in licensed third of core (appecximately 500 HTGR storage capac1:7 that has been elements). No change is planned.

enquascad or is 7== =d, in 7

t l

number of fuel assemblies.

t I

I..,_,. _ - - -.., -. - -. - - -, - - - - - - - -. -

-l------------------------------------

L v ::I: D7CEMA. ::N 6 a iwi 9.

Se prof ec:mi data of the 1986 under -de CL:sa Party A$rsemens (Coe-last raf-="-! dan can be

==ac: 1:' (04-3)-633) becueen. DCE, Public d' *-4="tod. :s 6a speac fssi Earv1== Company of Colorsde (?Sco), and 7 he pressac Ganara.L 1**

• Company.*

pool 1-"

L1=sased -- d:v.

ee I.986 da:a is based un -de underseadd 3 -Jac span: fual Ad ar6=@ durdsg

.he cars of de h ?ar:7 Ag:nnemmat sil:. he shipped :n da Idano Ni:1onst hr--1st Laborsc==y for starsgs by OCF. ac.hs Idaho Chd ~*' ? : cessing Plan (IC??). ":he storage aar- ' 7 has avidently been s1:ed to ac=cendata fual siz1=h is expec:ad en be d"*e6= sed. du=1sg the sight year period c.M.

by the 3rse Pa:Tr A6:a mmat.

9

---

,,---n-s-

,-+_e,-.,--,-~.._,,--..,,,-,-.a-,

.n,---,

,e--,.

.,w,

,,-m,e,--..--,m-_,,,,,w,-.r,,,n-~-

,.,-.~,--+.v.,.---.---