IR 05000395/1988024

Insp Rept 50-395/88-24 on 880926-30.No Violations or Deviations Noted.Major Areas Inspected:Witnessing Primary Containment Integrated Leak Rate Test & Review of Containment Integrated Leak Rate Test Procedure

ML20205M334
Person / Time
Site:	Summer
Issue date:	10/24/1988
From:	Jape F, Whitener H NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
To:
Shared Package
ML20205M328	List: IR 05000395/1988024 ML20205M324
References
50-395-88-24, NUDOCS 8811030038
Download: ML20205M334 (8)

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UNITED STATES j

i W NUCLEAR REOULATORY COMMISSION

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101 MARieTTA ST., e,,,, ' ATLANTA. GeOAGIA 30323 f l

f b Report No.: 50-395/88-24 L a l Licensee: South Carolina Electric and Gas Company }

Columbia, SC 29218 Docket No.: 50-395 License No.: NPF-12 Facility Name: Summer Inspection Conducted: Septembe,r 26-30, 1953  !

Inspector: M M, H.~ L: Wh'Itene r ~

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Date Signed

Approved by: // M M6 /0/.2>'/ !

F. Jape, Section Chief (/ / Date Sig'ned !

Test Programs Section l Engineeri;.g Branch r Division of Reactor Safety j r

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SUMMARY Scope: This routine, announced inspection was in the areas of witnessing the  !

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primary Containment Integrated Leak Rate Test (CILRT), review of the l CILRT procedure, evaluation of the CILRT results, and review of the  !

4 as-found leak rate for the primary containmen [

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Results: In the areas inspected, violations or deviations were not  :

, identifie Management involvement to assure a quality test was J l

evident in the use of detailed t.est controls and experienced leak rate test consultants. A conservative approach to technical issues was observed in the resolution of instrumentation and leakage f problems encountered during the test. Staffing was adequate in that r 1 in addition to consultant services, experienced SCE&G engineers were assigned as test directors on a shift basis. The inspector concluded ,

that the quality of the testing was acceptabl l

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REPORT DETAILS ,

i Persons Contacted Licensee 6mployees ,

i l *H. I. Donnelly, Senior Engineer, Regulatory Interface i J. S. Frick, Supervisor, Special Projects and Performance -

T. D. Gatlin, Shift Engineer ,

• D. R. Moore, General Manager, Engineering Services

• A. M. Paglia, Senior Engineer, Special Projects and Performance  !

• P. Quinton, Manager, Systems and Performance Engineering ,

• J. L. Skolds, General Manager, Nuclear Plant Operations Other Organizations [

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General Physics R. M. Carey, Manager, Containment Leak Rate Services  !

M. E. Jennex, Senior Engineer .

C. B. Koolstra, Staff Specialist [

1 t NRC Resident Inspectors l j

• L. Prevatte, Senior Resident Inspector l P. C. Hopkins, Resident Inspector l

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• Attended exit interview l l Containment Integrated Leak Rate Test (70313, 70307)  !

The inspector reviewed and witnessed test activities to determine that the primary CILRT was performed in accordance with the requirements of  :

Appendix J to 10 CFR 50, ANSI-N45.4-1972, test procedurt STP 206.001, i

"Integrated Leak Rate Test", and the criteria of BN-TOP-1, [

Revision 1-1972, for a short duration tes !

i Sele:ted smiing the licensee's activities which were inspected included: [

(1) review of test procedures to verify that the procedures were properly r approved and conformed with the regulatory requirements; (2) observation ,

of test performance to determine that test prerequisites were complete [

special equiprert was installed, instrumentation was calibrated, and >

appropriate data were recorded; and (3) preliminary evaluation of leakage l rate test results to verify that leak rate limits were me ;

i Pertinent aspects are discussed in the following paragraph [

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t General Observations L

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The inspector witnessed and reviewed portions of the test l preparation, temperature stabilization, and data processing during l i the period of September 26-30, 1988. The inspector's observations !

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!, (1) The test was conduct;i in accordance with an approved procedur ,

Procedure changes and test discrepancies were documente !

I i (2) Test prerequisites selected for review were found to be l complete ;

l (3) Selected plant systems required to maintain test control were f i found to be operatiena !

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(4) Special test instrumentation was reviewed and found to be !

installed and calibrate l

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l l (5) Controls for preventing pressurized air sources inside l

containment or externally pressurized penetrations were i

established in the test procedur ;

j i 4 (6) Instructions and documentation for venting and isolation of l l systems were established in the test procedur ('/) Problems encountered during the test were described in the test j event lo j i

j (8) A containment temperature survey was performed to determine t

representative locations of instruments, i

! I j (9) An in-situ check of CILRT instruments was perforced p rior to the )'

test.

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(10) Selected procedure valve alignments reviewed against system

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drawings to verify correct boundary alignment were adequat *

I (11) Temperature, pressure, humidity, and flow data were recorded at !

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l 15-minute intirvals. Data were assembled and retained for final '

j evaluation and analysis by the licensee. A final leak rate test

report will be submitted to the Office of Nuclear Reactor i Regulation pursuant to Paragraph V of Appendix J to 10 CFR 50.

l Procedure Review and Observations (70307)

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j portions of STP 206.001, Revision 2, "Integrated Leak Rate Test",

i dated September 16, 1938, were reviewed to verify that test l conditions, test controls, valve alignments and acceptance criteria !

l were specified. The inspector concluded that test conditions and

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4 controls were specified in detail in the text; and valve alignments, ,

l valve restoration, and system venting were specified in the 4ttacktent The inspector concluded that the procedure meets the limitations of .

10 CFR 50, Appendix A saeple of valve alignments in the test procedure which establish ,

the test boundary were reviewed in detail against up-to-date plant drawings to verify conformance with 10 CFR 50, Appendix J. The valve alignments whic.h were compared with plant drawings included the  !

following plant ystems: l l System Penetration Hydrogen Analyzer Inlet / Outlet 105 a and b

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Accumulater Sample Line 323

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Accumulator High Pressure N3 Supply 320 l P,reathing Air System 324 Charging to Regen. Hx 409 :

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RCOT to Vent Header and H 2 418 RC to Letdown Hx 318 l l

l CRDM Cooling Water Outlet 209 .

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Seal Water Return 410 Seal Water Injection 221 1 i

Based on the sample review, the inspector concluded that valve alignments conform to Appendix J requirement j c. Containment Integrated Leak Rate Test (CILRT) performance (70313) -

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(1) Method The integrated leak rate test was performed at the calculated  !

accident pressure (Pa) by the absolute test method. Acceptance criteria were included in the test procedure for Mass Point, Total Time and Short Duration testing in accordance with the r specifications of ANSI /ANS-56.5-1931, "Containment System i Leakage Testing Requirements"; ANSI-N45.4-1972, "Leakage-Rate f Testing of Containment Structures for Nuclear Reactors"; and l f

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r BN-TOP-1, Revision 1-1972, "Testing Criteria for Integrated [

Leakage Rate Testing of Primary Containment Structures for  ;

Nuclear Power Plants", respectively, j The computer program for analysis of test data was provided by  :

General Physic The program included capability for analysis i of test data according to the 24 ass Point, Total Time er Short t Outstion test methodologies. N test analysis was performed l using the Total Time methodology. The test duration was 24 '

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(2) Description Values bounding the test conditions were as follows:

Containment Vslume 1,040,000 cubic feet Accident Pressure (Pa) 47.1 psig .'

Maximum Allowable Leakage (La) 0.2 wt % per day l i

System conditions for performance of the integrated leak rate ,

test were as follows: -

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Reactor Vessel -

Vented to containment atmospher .

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RHR System -

Operating to provide  !

decay heat removal Containment Venttiation System - Fans tripped: No fo ced ,

i air flow.

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Containment Isolation System - Vented, drained, and !

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aligned per procedure l

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STP 206.00 <

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After inspection of the containment structure, the prirna ry [

contatnnent was closed and pressur'zation initiate The [

l following table is a brief description of events extrseted from  ;

the test lo [

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09/26 1040 5 tarted pressurization of the primary containment, f

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1240 Secured pressuiiration at 10 psig, l performed leakage surve Only minor [

1eakage detecte i f

1400 Continue pressurizatio l r

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Dat Time' Event-(cont'd)

R Secure'd pressurization at 50 psi Air compressors vente Began stabilization perio /27 0225 Oue to large . temperatura change and resulting pressure drop, the containment was repressurized to 50.1 psi Repressurization secure Sta r, time for ILRT . declared. This was subsequently changed to 0700 to provide 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> from time of repressurization.

Y 0900 Some large perturbations in data appear to be the result of the dew cell cleaning (Pacer) cycl Leakage through flanges on penetrations 201, 210, and 211 repaired. Although a part of the test boundary this condition is not a part of the containment boundar Repair does not represent a failed test, but does require restar Time zero established at 1500 hour0.0174 days <br />0.417 hours <br />0.00248 weeks <br />5.7075e-4 months <br /> Total Time UCL at 0.3 wt.%. Trend indicates that the test will' not meet the BN-TOP-1 criteri /28 1500 End of 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> Total Time test. Leak rate =

0.09 wt.%; UCL = 0.11 wt.%.

1630 Verification test starte Delay due to improper installation of flow meter floa .5 Verification test complete d. Test Analysis and Results (1) Type A Test The Technical Specifications for Summer specify the a'.lowable-containment leak rate as 0.2 wt.% per day of the containment volume at the calculated accident pressure (Pa) of 47.1 psi Therefore, the acceptance limit for the integrated leak rate (Type A) test of 0.75 La is 0.15 wt.% per day. Analysis of 24

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6-hours of data from 3:00 p.m. 9/27 to 3:00 p.m. 9/28, using Total Time methodology yields a leak rate of 0.09 wt.% per day. The 95% Upper Confidence limit (UCL), when calculated at the 24th hour without conservative factors required for a less than 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> test, yields a leak rate of 0.109 wt.% por day. These values are within the acceptable limit of 0.15 wt.% per da The inspector calculated weighted averages for containment

, temperature, pressure, and vapor pressure using the weighting factors and individual sensor data for a sample of data sets to verify agreement with the -weighted averages and mass calculations generated by the licensee's computer progra Subsequently, the mass points generated by' the licensee's program were used by the inspector to calculate the leak rate, and the 95% upper confidence leak rate. The inspector's calculations agreed with the licensee's calculation (2) Supplement Test Appendix J requires that a supplemental test be performed to verify the accuracy of the Type A test and the ability of the CILRT instrumentation to measure a change in leak rate. An acceptable supplemental test method is described in Appendix C of ANSI-N45.4-1972, as follows:

A knowr. leak rate (Lo) is imposed on the containment and the measured composite leak rate (Lc) must equal, within

+ 0.25 La, the sum of the measured Type A leak rate (Lam)

plus the known leak rate (Lo).

A 4.25 hour2.893519e-4 days <br />0.00694 hours <br />4.133598e-5 weeks <br />9.5125e-6 months <br /> supplemental test was performed by the imposed leak rate method described in Appendix C to ANSI-N45.4-1972. The following values in units of wt.%/ day were obtained using fotal Time analysi Total Time (wt.%/ day)

Lam 0.0904 Lo 0.2125 0.25 La 0.05 Lc 0.2712 Using these values in the acceptance criteria yields the following: 1 0.2529 s 0.2712 s 0.3529 Lc = C.2712 satisfies the above inequality and therefore, the supplemental test is acceptabl _ _________ - ___ -_-_ _-____ _ _ - _ _

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The inspector cencluded that the containment leak rate meets the Appendix J and Technical Specification 4.6 requirement . Issues' Reviewed o

During the initial stabilization, a significant pressure drop occurred as a result .of a large drop in containment air temperature. The licensee decided to repressurize the containment _ between 2:00 a.m. and 3:00 a.m. ,

on September 7.7, 1988. The Type A test was subsequently started at 6:00 a.m., on September 27, 1988. This matter was - discussed with the

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licensee and the start time was moved to 7:00 a.m., to allow a minimum-four (4) hours stabilization. Due to an apparent high. leak rate during the following hours, the licensee decided to make leakage repairs between 2:00 and 3:00 p.m., on September 27, -1988. Due to the changed leakage rt.te, the tett start time was moved to 3:00 p.m., on September 27, 198 The insoector reviewed the repaired leakage paths and concluded that the leakage occurred in flanges which had been altered to permit pressurization and depressurization of the containment and for test instrvment installation. Local leak rates of the' blind flanges normally on these penetrations prior to disassembly of these flanges showed no leakage in the normal -containment boundary. Local leak rate tests are also performed after the flanges are reassembled for plant operatio The inspector ccncluded that these repairs did not represent a failed leak ra te tes Since the Type A test was performed prior to repair or adjustment to the containment boundary, this test represents a successful

"as-found" leak rat At the beginning of the verification test, the imposed leakage flow as less than the expected flo Investigation showed that the float was upside down. The rotameter was disassembled and the float inverted. This

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yielded an air flow in the range anticipated. The licensee stated that a i post test calibration of the rotameter would be performed to confirm the

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accuracy of the flow rate.

The inspector considered the issues reviewed during the integrated leak rate test to be adequately resolved.

l Exit Interview

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The inspection scope and results were summarized of September 30, 1988,

with those persons indicated in paragraph 1. The inspector described the l areas inspected and discussed in detail the inspection results.

l Proprietary information is not contained in this repor Dissenting 4 comments were not received from the licensee.

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