ML20028G296

Nonproprietary VC Summer Station Interim Power Operation Evaluation Rept.

ML20028G296
Person / Time
Site:	Summer
Issue date:	01/31/1983
From:	WESTINGHOUSE ELECTRIC COMPANY, DIV OF CBS CORP.
To:
Shared Package
ML19303B509	List: ML20028G288 ML20028G293 ML20028G296
References
SGP-9.2-3009R, NUDOCS 8302070602
Download: ML20028G296 (9)

Text

2..  :... . . :.. . . :. . -. :

c..a .

A SGP-9.2-3009R V. C. SUPMER STATION INTERIM POWER OPERATION EVALUATION REPORT JANUARY 1983 WESTINGHOUSE ELECTRIC CORPORATION P.O. Box 355 Pittsburgh, PA 15230 i

Y PPDR ADOCK8302070602 05000395 830131 l

\

PDR t

(\

?.. :. .- -

.:;....=.. :==- -

V. C. SW9ER STATION INTERIM POWER OPERATION EVALUATION REPORT JANUARY 1983 TABLE OF CONTENTS

1. INTRODUCTION

- 2. OPERATIONAL EXPERIENCE

3. TUBE VIBRATION TESTING

4. POWER OPERATION EVALUATION

5. SUP94ARY e

9 e

jr. . . . . .

.a .\ i-i . ~ x s. -

fl..ix:. . a ;,.i s-:- 2 1 ;;.* G L ...*.. . ..

l t *

1. Ilmt000CTION A previous report " Interim Power Operation Evaluation Report.

V. C. Sumner. September 1982" (hereafter referred to as the September 1982 Report) has provided the technical basis for initial operation of the Virgil C. Summer Station up to 50% power for 2000 hours0.0231 days <br />0.556 hours <br />0.00331 weeks <br />7.61e-4 months <br />. prior to steam generator modification to address the issue of tube wear at baffle plate locations in the outer tube rows.

This report presents a basis for extending this initial 2000 hour0.0231 days <br />0.556 hours <br />0.00331 weeks <br />7.61e-4 months <br /> period by 1000 hours0.0116 days <br />0.278 hours <br />0.00165 weeks <br />3.805e-4 months <br /> at 50% power and with limited operation at 60, 75, 90 and 100% for plant startup testing. Details of the proposed power operation program are presented in Table A.

' TABLE A VIRGIL C. SUPMER STATION PROPOSED OPERATING PROGRAM Time Period 1 Full Power Main Nozzle Flow 2000 hours0.0231 days <br />0.556 hours <br />0.00331 weeks <br />7.61e-4 months <br /> 50%

1000 hours0.0116 days <br />0.278 hours <br />0.00165 weeks <br />3.805e-4 months <br /> consisting of:

24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> 60%

336 hours0.00389 days <br />0.0933 hours <br />5.555556e-4 weeks <br />1.27848e-4 months <br /> 75%

24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> 90%

24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> 100%

592 hours0.00685 days <br />0.164 hours <br />9.78836e-4 weeks <br />2.25256e-4 months <br /> 50%

l l

l l

-l

..1... . . . .....j........

l, -

1

2. OPERATIONAL EXPERIENCE The September 1982 report provided an assessment of V. C. Summer's l

2000 hour0.0231 days <br />0.556 hours <br />0.00331 weeks <br />7.61e-4 months <br /> /5OE power operating program by comparing this program with the operating experience at other plants with split flow steam generators. Plant operating experience, as presented in the l September 1982 report, is summarized below:

Plant A Plant A started up in the fall of 1980 and, up to shutdown in October 1981, had operated at power levels at or greater than l 50 percent for more than 3000 hours0.0347 days <br />0.833 hours <br />0.00496 weeks <br />0.00114 months <br />. plant A was shut down in j October 1981 with primary-to-secondary leakage. Subsequent l inspection revealed that one tube was leaking on the cold leg f side in the pre-heat section of one steam generator. Eddy current test (ECT) inspection of all three steam generators revealed wear indications in general on tubes in the first three rows of each

- steam generator.

Plant A returned to power in April 1982. Although Westinghouse recomended operation at 47 percent of main feed flow, the unit, was operated at 40 percent of main feed flow (with short intervals at higher power levels to obtain instrumentation data) for an approximate 1500 hour0.0174 days <br />0.417 hours <br />0.00248 weeks <br />5.7075e-4 months <br /> operating period. This period ended in  :

June 1982.

An eddy current inspection was performed in June,1982 and those results compared with the March,1982 inspection. The June,1982 data resulted in a decrease in the total number of indications but a slight increase in the size of the larger indications.

plant A returned to power in August,1982 and operated at 40 percent of main feed flow for approximately 2000 hours0.0231 days <br />0.556 hours <br />0.00331 weeks <br />7.61e-4 months <br /> before shutdown in November,1982.

a

, * ~.

.L .~d. .

plant 8 plant 8 started up in the spring of 1981 and, up to shutdown in November,1981, had operated at power level at or greater than ,

50 percent for more than 2000 hours0.0231 days <br />0.556 hours <br />0.00331 weeks <br />7.61e-4 months <br />. plant B was shut down in early November,1981 to perform ECT inspections of steam generator tubes. A pattern of indications similar to, but less pronounced than, that at Plant A was found.

Plant B returned to power in December,1981 for an approximate 1500 hour0.0174 days <br />0.417 hours <br />0.00248 weeks <br />5.7075e-4 months <br /> operating period at 50 percent of main feed flow (with short intervals at higher power levels to obtain instrumentation data). This period ended in March 1982. ECT inspection of the steam generators was performed, and it was concluded that little, if any, wear had occurred.

Plant B returned to power in April, 1982 for an approximate 2000 hour0.0231 days <br />0.556 hours <br />0.00331 weeks <br />7.61e-4 months <br /> operating period (which ended in July,1982) at 50 percent main feed flow. A photographic evaluation of the ECT data from  ;

the March and July inspections was performed by Westinghouse, with the conclusion that there has been no significant change in tube wear due to this operating period.

Plant B returned to power in September,1982 and has subsequently operated'at 50% main feed flow for over 2000 hours0.0231 days <br />0.556 hours <br />0.00331 weeks <br />7.61e-4 months <br />.

Plant C Plant C performed startup testing in late 1981 and operated at various power levels up to 100 percent through February,1982, accumulating 1500 hours0.0174 days <br />0.417 hours <br />0.00248 weeks <br />5.7075e-4 months <br /> of operation at and above 50 percent power.

including 324 hours0.00375 days <br />0.09 hours <br />5.357143e-4 weeks <br />1.23282e-4 months <br /> at and above 75 percent power. ECT inspection following shutdown in February,1982 revealed only minor degradation l

l ( <20 percent throughwall penetration by differential ECT) on four tubes after this first period of operetion.

4 1

A _ , _ _ . -

g .,,... - ._ _. . . : c -

l

- l l

' # From March to June,1982, Plant C operated for 1500 hours0.0174 days <br />0.417 hours <br />0.00248 weeks <br />5.7075e-4 months <br /> at 50 percent main feed flow, followed by 710 hours0.00822 days <br />0.197 hours <br />0.00117 weeks <br />2.70155e-4 months <br /> at 75 percent.

An eddy current inspection was performed and it was concluded that some wear had occurred but was difficult to quantify due to the varying inspection techniques.

Plant C returned to power in July,1982 and operated for approxi-mately 1800 hours0.0208 days <br />0.5 hours <br />0.00298 weeks <br />6.849e-4 months <br /> at 50 percent and 700 hours0.0081 days <br />0.194 hours <br />0.00116 weeks <br />2.6635e-4 months <br /> at 75% main feed flow before shutdown in November,1982.

In sumary, there has been no significant tube wear observed in plants under operating conditions proposed herein for V. C. Sumer.

In particular, the experience of Plant B at 50% for over 3500 hours0.0405 days <br />0.972 hours <br />0.00579 weeks <br />0.00133 months <br /> without significant tube wear at.d the experience of Plant C at E50%

for 1500 hours0.0174 days <br />0.417 hours <br />0.00248 weeks <br />5.7075e-4 months <br /> and ate 75% for 324 hours0.00375 days <br />0.09 hours <br />5.357143e-4 weeks <br />1.23282e-4 months <br /> with minor degradation is relevant. (Plants which have significant tube wear indications have operated extensively at power levels of 75% and above prior to the inspection which indicated the significant levels of wear.) Consequently, the proposed power operation program for V. C. Sumer should not result in more than minor levels of wear.

3. TUBE VIBRATION TESTING Tube vibration measurements taken at V. C. Summer in December,1982 provide 'for an additional comparison between V. C. Sumer and other operating plants with split flow steam generators. For these measurements, accelerometers were installed in R49C51 and R49C67, (window and non-window tubes, respectively, in Steam Generator A) and data was obtained at power levels ranging from hot shutdown to 48%

power. It was concluded from these tests that _ _ , ,

l l

e M

3:w:a ~ v-s ~e.--

. .a .v r.- :~~.

l l

operated for a time period considerably in excess of 2000 hours0.0231 days <br />0.556 hours <br />0.00331 weeks <br />7.61e-4 months <br /> at 50 percent power, without evidence of tube wear during 50 percent power operation.

4. POWER OPERATION EVALUATION The September,1982 Report indicated that the V. C. Sumer Station should be operated at 4 0% power (.not exceeding 50% of full power feedwater flow to the main feedwater nozzle) for a period of up to 2000 hours0.0231 days <br />0.556 hours <br />0.00331 weeks <br />7.61e-4 months <br />. Further studies have been perfomed to evaluate the feasibility of extending the operational cycle.

Tube wear estimates, as quoted in the September 1982 Report, were extended to show the effect of increasing the operational period from 2000 to 3000 hours0.0347 days <br />0.833 hours <br />0.00496 weeks <br />0.00114 months <br />, at 50%. In addition, tube wear estimates were extended to include the power history shown in Table A. These estimates are shown in Table B for the most susceptible location on the potentially most affected tube. Extending the operating period from 2000 to 3000 hours0.0347 days <br />0.833 hours <br />0.00496 weeks <br />0.00114 months <br />, at 50% power, increases the best b

estimate tube wear ca'culat. ion

, c. e.from L

[a'n'dtheupper bound from } Furtherinore, for the operating history of Table A, the best estimate and upper bound tube wear is calcu-p ., .c,<_

latedtobe{ ,1respectively. The fraction of tube wear calculated for individual power levels of the Table A power history'is shown in Table C.

1 5

r .. .

. .f

~

..: ...r  : .

t,s. .%.*.T.... L'.:= r = r r:.. . . .

l

- TABLE 8 VIRGIL C. 3459ER STATION ESTIMATED TUBE WEAR Tube Wear _Estimete*

Best Estimate Upper Bound Operation Program -

. ,c. ,e,_

2000 hours0.0231 days <br />0.556 hours <br />0.00331 weeks <br />7.61e-4 months <br /> at 50%

3000 hours0.0347 days <br />0.833 hours <br />0.00496 weeks <br />0.00114 months <br /> at 50%

Table A Power History 1 TABLE C VIRGIL C. SUlt1ER STATION POWER PROFILE TUBE WEAR FRACTION Tube Wear Best Estimate

• F actioq of,*

Operation Program 5 _ E1

- - . ,c.,e 2000 hours0.0231 days <br />0.556 hours <br />0.00331 weeks <br />7.61e-4 months <br /> at 50%

24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> at 60%

336 hours0.00389 days <br />0.0933 hours <br />5.555556e-4 weeks <br />1.27848e-4 months <br /> at 75%

24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> at 90%

24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> at 100%

592 hours0.00685 days <br />0.164 hours <br />9.78836e-4 weeks <br />2.25256e-4 months <br /> at 50% _.

• Percent through-wall penetration at most susceptible location for potentially most affected tube.

I I . -_ ,

'.m. . . _ _ . _ _ _ . .. .. . . . . . . . . . . . .. .,

. E'*. ~-_ -- _.

. . . . :. : . = .= :. .- -- : - . . . .' .

., * - ^ . :: . =. _ = : . . . .

l l

l

4. SupMARY l

An interia operating program defined in Table A of this report "

has been evaluated for operation of the Virgil C. Summer Station.

on the basis of precluding significant steam generator tube wear.

The tube wear for this proposed program has been avaluated by a quantitative assessment of wear using existing Westinghouse correlations, a comparison of the proposed V. C. Seaner operating program with operational experience at other plants with split flow steam generators ar.d a comparison of V. C. Sumner tube vibration measurements with equivalent measurements in other split flow steam generators. The result of this evaluation is that significant tube wear should be precluded by adhering to the proposed program.

l

-_. - . - -