ML18153C610

Forwards Corrected Pages to Containment Integrated Leak Rate Test Rept.Evaluated Impact of Errors.Determined That Overall Results of Test Not Changed

ML18153C610
Person / Time
Site:	Surry
Issue date:	04/29/1991
From:	Stewart W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
91-124, NUDOCS 9105070263
Download: ML18153C610 (14)

Text

e VIRGINIA ELECTRIC AND POWER COMPANY RICHMOND, VIRGINIA 23261 April 29, 1991 United States Nuclear Regulatory Commission Attention: Document Control Desk Washington, D. C. 20555 Gentlemen:

VIRGINIA ELECTRIC AND POWER COMPANY SURRY POWER STATION UNITS 1 AND 2 CORRECTIONS TO PREVIOUSLY SUBMITTED Serial No.

NO/ETS Docket Nos.

License Nos.

CONTAINMENT INTEGRATED LEAK RATE TESTING REPORTS91-124 50-280 50-281 DPR-32 DPR-37 A recent Quality Assurance audit of the lnservice Inspection Program has identified errors in the Containment Integrated Leak Rate Test Reports submitted to your office in November 1986 and June 1988 for Unit 2 and Unit 1, respectively.

We have evaluated the impact of these errors and have determined that the overall results of the test were not changed. Each test remains a successful test with acceptable "as-found" and "as-left" results. The current Type A Test Program requires verification of the assumptions and data analysis, which will preclude similar problems with future Type A Tests.

The corrected pages for the two tests are included as attachments to this letter. The revisions on each page are identified by bars in the right hand margins.

Please replace the applicable pages from ou.r previous reports with these corrected pages.

Should you have any questions, please contact us.

v~~~

\\],

W. L. Stewart Senior Vice President - Nuclear Attachment's,

1. Revisions to Unit 2 November 1986 Test Report

2. Revisions to Unit 1 June 1988 Test Report

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ATTACHMENT 1 CORRECTED PAGES FOR THE SURRY UNIT 2 NOVEMBER, 1986 TYPE A TEST REPORT

cc:

U. S. Nuclear Regulatory Commission Region II 101 Marietta Street, N. W.

Suite 2900 Atlanta, Georgia 30323 Mr. W. E. Holland NRC Senior Resident Inspector Surry Power Station e

4.0

SUMMARY

4.1 TYPE A TEST The CILRT that was performed on Surry Unit Two was satisfactorily completed on November 20, 1986.

The final Upper Confidence Limit (UCL) leakage results, including the required penalties, was 0.064112 wt %/day.

The value is well below the acceptable limit of. 075 wt %/day and clearly demonstrates that the integrity of the containment has met the criteria in Paragraph III.A.5.(b).(2) of Reference 1.1.

Containment pressurization began at 2335 hours0.027 days <br />0.649 hours <br />0.00386 weeks <br />8.884675e-4 months <br /> on November 17, 1986.

Pressurization continued until 0905 hours0.0105 days <br />0.251 hours <br />0.0015 weeks <br />3.443525e-4 months <br /> on November 18, 1986.

Prior to the start of pressurization, Penetration 70, MOV-RS-256B, was blanked off due to excessive seat leakage on the valve.

It was decided that the valve would be worked after the-Type A test since the amount of time required to repair the valve would-delay the start of the Type A test.

The pre-repair Type C test minimum pathway leakage results for that penetration were added to the final Type A test results.

The valve had an As-Found minimum pathway leakage of 1. 6 SCFH.

A minimum pathway leakage of 0.000535 wt %/day was added to the final UCL leakage results.

During the course of the stabilization period, walkdowns were performed on various areas to identify any possible leakage paths.

Four vented penetrations 4.1

e 4.1 TYPE A TEST (CONT)

Actual containment leakage, see Attachment 7.1, was.062 wt

%/day at the beginning of the test and was.029 wt %/day at the end of the test. This variance resulted in the confidence limit being higher than normal.

The Type A test was extended for 32 hours3.703704e-4 days <br />0.00889 hours <br />5.291005e-5 weeks <br />1.2176e-5 months <br /> to allow the confidence limit to continue a slow but steady decrease to within acceptable limits.

A major contribution to the extended test duration was the use of instantaneous data

( containment

pressure, dewpoint temperature and average temperature) from the P250 computer instead of the ten minute averaged values which were used on previous CILRT's.

The instantaneous values had more scatter than we had normally seen with the averaged values.

If the program that utilized averaged values was used, the Type A test could have been satisfactorily completed in approximately 20 hours2.314815e-4 days <br />0.00556 hours <br />3.306878e-5 weeks <br />7.61e-6 months <br /> using the same UCL leakage as in the instantaneous test results (See Attachment 7.2).

The Type A test was satisfactorily completed at 1300 hours0.015 days <br />0.361 hours <br />0.00215 weeks <br />4.9465e-4 months <br /> on November 20, 1986 with a UCL leakage of.063451 wt %/day.

With the Type C test penalties added to the test results, the final leakage was 0.064112 wt %/day.

4.3

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ATTACHMENT 7.8 NRC PROPOSED PENALTIES PENETRATION NUMBER 46 56A 63 64 66/67 68/69 71 TOTAL FINAL TYPE A TEST RESULTS TYPE A TEST LEAKAGE WITH NRC PROPOSED PENALTIES TYPE C Page 1 of 1 LEAKAGE o.o 0.0354 o.o o.o

1. 75

1. 51 0.60 3.8954 OR

.001304

.064112 0.065416 (SCFH)

WT %/DAY WT %/DAY WT %/DAY

'w.

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PENETRATION 23 28 33 38 42 43 46 58 60 61 64 66/67 68/69 90 94 EQUIPMENT HATCH PERSONNEL HATCH ELECTRICAL ATTACHMENT 9.1 AS-FOUND TYPE A TEST ANALYSIS PRE-REPAIR POST-REPAIR LEAKAGE NOTE MINIMUM MINIMUM SAVINGS PATHWAY PATHWAY LEAKAGE LEAKAGE

.173 0.000

.173 1

18.660 0.000 18.660

.090 0.040

.050

>300.000 0.000

>300.000 2

.040 0.000

.040

.liO 0.020

.090

>300.000 0.000

>300.000 3

.340 0.000

.340 4.600 4.130

.470 4

2.600

1. 510 1.090 4

.200 0.000

.200 5

1. 850

1. 750

.100 6

4.300 1.510 2.790 7

4.300 3.100 1.200

.600 0.550

.050 2.130 1.170

.960 15.600 9.750 5.850

.021 0.017

.004 TOTAL SAVINGS 27.244 TOTAL LEAKAGE SAVINGS 27.244 (SCFH)

TOTAL LEAKAGE SAVINGS

.0091178 WT%/DAY TYPE A TEST RESULTS

.064112 WT%/DAY TOTAL LEAKAGE SAVINGS

.0091178 WT%/DAY AS-FOUND TYPE A TEST RESULTS.0732298 WT%/DAY PAGE 1 OF 4

e e

ATTACHMENT 2 CORRECTED PAGES FOR THE SURRY UNIT 1 JUNE, 1988 TYPE A TEST REPORT

4.2 SUPERIMPOSED VERIFICATION TEST The superimposed verification test was started at 1726 hours0.02 days <br />0.479 hours <br />0.00285 weeks <br />6.56743e-4 months <br /> on June 25, 1988 with a leakage of approximately 5.00 SCFM being registered on the flow meter.

The stabilization period for the superimposed verification test ended at 1930 hours0.0223 days <br />0.536 hours <br />0.00319 weeks <br />7.34365e-4 months <br /> on June 25, 1988.

At that time, leakage rate calculations were started.

The superimposed verification test then continued for approximately 9.75 hours8.680556e-4 days <br />0.0208 hours <br />1.240079e-4 weeks <br />2.85375e-5 months <br />.

The final superimposed leakage rate value was 0.098316 wt%/day and satisfactorily met the acceptance criteria in Attachment 7.17 of Ol-PT-16.3.

Depressurization of containment commenced at 0928 hours0.0107 days <br />0.258 hours <br />0.00153 weeks <br />3.53104e-4 months <br /> on June 26, 1988 and was completed at 1858 hours0.0215 days <br />0.516 hours <br />0.00307 weeks <br />7.06969e-4 months <br /> on June 26, 1988. Post CILRT containment inspection was conducted at 2030 hours0.0235 days <br />0.564 hours <br />0.00336 weeks <br />7.72415e-4 months <br /> on June 26, 1988.

4. 3 CONTAINMENT LINER TEST CHANNELS A general inspection of the accessible interior surfaces of the containment structure was performed, as required by Ol-PT-

16. 3, prior to the Type A test. This inspection is performed for the purpose of identifying evidence of deterioration in the containment liner which may affect the containment integrity.

During the walkdown, a

leak-chase channel test plug was discovered missing along the interior wall between "A" and "B" Loop Rooms.

No other plugs were discovered missing during the walkdown which covered the readily-accessible interior surface of containment.

While performing other Type A related activities, using scaffolding that was erected for other containment work, several normally inaccessible areas of the liner were able to be examined for missing channel test plugs.

Two leak-chase channel test plugs were discovered missing.

One was located in the 4.2

e Substituting actual test results, the above equation turns out to be:

(.021834 +.09968 -.025) ~.098316 ~ (.021834 +.09968 +.025) 0.096514 < 0.098316 ~ 0.146514 As shown above, Le falls within the limits of the equation.

7.2

TYPE C PENALTIES e

ATTACHMENT 7.5 CILRT TEST RESULTS The Type C penetration leakages listed below are to be added to the Type A test results because the penetrations could not be vented during the test.

PENETRATION NO.

19 20 24 28 32 33 38 45 50 55A 56B 56D 57A 63 64 70 71 92 93 97B 97C 100 101 105D 106 DESCRIPTION CHARGING SAFETY INJECTION RESIDUAL HEAT REMOVAL CHARGING GASEOUS WASTE PRIMARY DRAINS AERATED DRAINS PRIMARY GRADE WATER SAFETY INJECTION LEAKAGE MONITORING SAMPLE SYSTEM SAMPLE SYSTEM LEAKAGE MONITORING CONTAINMENT SPRAY CONTAINMENT SPRAY RECIRCULATION SPRAY RECIRCULATION SPRAY GASEOUS WASTE GASEOUS WASTE SAMPLE SYSTEM LEAKAGE MONITORING GASEOUS WASTE FIRE PROTECTION LEAKAGE MONITORING SAFETY INJECTION TOTAL TYPE C LEAKAGE TOTAL TYPE C LEAKAGE PAGE 1 OF 2 LEAKAGE (SCFH) 0.05 o.o 0.522 0.046 o.o o.o 0.109 9.9 0.11 o.o o.o o.o o.o 0.507 0.06 1.524 o.. 664 0.191 o.o o.o o.o o.o o.o o.o o.o 13.683 ~CFH 0.004579 WTt/DAY

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ATTACHMENT 7.5 (CONT'D)

CILRT TEST RESULTS MASS POINT LEAKAGE 95% CONFIDENCE LIMIT TYPE C PENALTIES FINAL TYPE A TEST RESULTS 0.021834 WT %/DAY 0.006016 WT %/DAY 0.004579 WT %/DAY 0.032429 WT %/DAY The acceptable limit of. 075 wt %/day as stated in Paragraph III.A.5. (b). (2) of Reference 1.1 was met.

PAGE 2 OF 2

9.0 AS-FOUND TYPE A TEST ANALYSIS (CONT'D)

An analysis was performed on those penetrations that are considered credible leakage paths during the first hour of the

accident, prior to the containment returning to a

subatmospheric pressure.

The penetrations identified by note 1 through 4 in Attachment 9. 1 are excluded as credible leakage sources.

The analysis and technical justification for excluding these specific penetrations was submitted to the NRC in correspondence dated November 16, 1987, August 5, 1988 and August 15, 1988.

(Serial Numbers 87-707A, B, & C)

RESULTS As noted in Attachment 9.1, the as-found integrated leak rate was o. 0509 wt %/day which is less than the acceptance criteria of 10CFR50 Appendix J (0.075 wt %/day).

9.2

ATTACHMENT 9.1 (CONT'D) 1988 "AS-FOUND" LLRT LEAKAGE

SUMMARY

CILRT RESULTS

1.

NET LEAKAGE SAVINGS 68.8665 SCFH

2.

NET LEAKAGE SAVINGS 0.02305 WT %/DAY

3.

"AS-FOUND" TYPE A TEST RESULTS A.

MASS POINT RESULTS

• O. 02785 WT %/DAY B.

NET LEAKAGE SAVINGS 0.02305 WT %/DAY

c.

"AS-FOUND" RESULTS 0.0509 WT %/DAY PAGE 3 OF 5