IR 05000324/1987015

Insp Repts 50-325/87-15 & 50-324/87-15 on 870515-22.No Violations or Deviations Noted.Major Areas Inspected: Witnessing of Unit 1 Primary Containment Integrated Leak Rate Test & Followup Insp of Outstanding Item for Unit 2

ML20235L924
Person / Time
Site:	Brunswick
Issue date:	07/07/1987
From:	Jape F, Whitener H NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
To:
Shared Package
ML20235L921	List: IR 05000324/1987015 ML20235L919
References
50-324-87-15, 50-325-87-15, NUDOCS 8707160873
Download: ML20235L924 (11)

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'ARich UNITED STATES -

NUCLEAR REGULATORY COR9 MISSION j

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REGION 11

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j 101 MARIETTA STREET,N.W.

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ATLANTA, GEORGI A 30323

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Report Nos.: 50-325/87-15 and 50-324/87-15 Licensee:

Carolina Power and Light Company P. O. Box 1551 Raleigh, NC 27602

~ Docket'Nos.:

50-325 and 50-324 License Nos.:

DPR-71.and DPR-62

. Facility Name:

Brunswick 1 'and 2 Inspection Conducted:

May 15-22, 1987

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Inspector: NIM

/mp 7 /7 [k7 H. L. Whitener Date 51gned'

Approved by:

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IWap !,' Sect,loff CTilef J ~

Uate Signed Division of Reactor Safety SUMMARY Scope:

This-routine, announced inspection was in the ' areas of witnessing the Unit 1 primary containment integrated leak rate test (CILRT), review of the CILRT procedure, tem for Unit 2. evaluation of the CILRT results, and followup inspection an outstanding i Results:

No violations or deviations were identified.

8707160873 0707D9 PDR ADOCK 05000324

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i REPORT DETAILS 1.

Persons Contacted Licensee Employees

• P. W. Howe, Vice President, Brunswick Nuclear Project

• C. R. Dietz, General Manager

• E. A. Bishop, Manager, Operations

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• E. R. Eckstein, Manager, Technical Support

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• J. G. Titrington, Engineering Supervisor, ISI i

• L.W.Wheatly,ProjectEngineer,LeakRateTestDirector ISI

• M. S. Blinsen Specialist, ISI,

• R. M. Poulk, 5enior Specialist, Regulatory Compliance

l Other licensee employees contacted included engineers and technicians

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associated with the leak rate testing.

Other Organization United Energy Services Corporation

R. E. Shirk, ILRT Engineering Consultant J. J. Blessing, ILRT Engineering Specialist NRC Resident Inspectors

• W. Ruland, Senior Resident Inspector L. Garner, Resident Inspector

• Attended exit interview 2.

Exit Interview The inspection scope and findings were summarized on May 22, 1987, with those persons indicated in parag,raph 1 above.

The inspector described the areas inspected - and discussed in detail the inspection findings.

No dissenting comments were received from the licensee.

The following new item was identified during this inspection.

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The licensee requested that Region II reevaluate the Unit 2 contain-ment integrated leak rate test performed in September 1984, which was declared a failed test.

The licensee did not identify as proprietary any of the materials provided to or reviewed by the inspector during this inspection.

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3.

Licensee Action on Previous Enforcement Matters

(Closed) Violation 50-324/81-04-02 concerned the failure to promptly report snubber functional test failures when performed with the plant at

)ower.

The inspector reviewed the licensee's response, serial io. 81-1020, dated June 12, 1981, and verified that the licensee has taken appropriate corrective action.

The snubber functional test, PT 19.6.1 is

now performed during plant shutdown and Reg,ulatory Compliance must sign off on the completed test procedure.

The violation was identified to the i

licensee at an exit interview of March 26, 1981.

The inspector verified

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that when an inoperable snubber was identified on April 14, 1981, on Unit 1 with the plant at 75% full power, a written followup report was submitted to Region II within two weeks.

Violation 50-324/81-04-02 is closed.

4.

Unresolved Items Unresolved items were not identified during this inspection.

5.

Containment Integrated Leak Rate Test - Unit 1(70313,70307)

The inspector reviewed and witnessed test activities to determine that the primary containment integrated leak rate test (CILRT) was performed in accordance with test procedure PT-20.5, gpendix JIntegrated Primary Containm the requirements of A to 10 CFR 50, ANSI-N45.4-1972, Leak Rate Test" and the criteria of BN-TOP-1, Revision 1-1972, for a short duration test.

Selected samp) ling of the licensee's activities which were inspected included:

(1 review of the test procedures to verify that the procedures were properly approved and conformed with the regulatory requirements; (2) observation of test performance to determine that test prerequisites were completed, special equi) ment was installed, instrumentation was calibrated and appropriate cata were recorded; and (3) preliminary evaluation of leakage rate test results to verify that leak rate limits were met.

Pertinent aspects are discussed in the following paragraphs.

a.

General Observations The inspector witnessed and reviewed portions of the test preparation, temperature stabilization and data processing during the

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period of May 15-22, 1987.

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The test was conducted in accordance with an approved procedure.

Procedure changes and test discrepancies were properly documented in the procedure.

The inspector's observation i

included the following:

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Test prerequisites selected for review were found to be

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completed.

Selected plant systems required to maintain test control

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were found to be operational.

Special test instrumentation was reviewed and found to be

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installed and calibrated.

Controls for preventing pressurized air sources inside

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containment or externally pressurized penetrations were est h ished in the test procedure.

Instructions and documentation for venting, draining, and

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isolation of systems were established in the test procedure.

Problems encountered during the test were described in the

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test event log.

A containment temperature survey was performed for a

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similar containment during a previous CILRT.

Temperature, pressure, humidity, and flow data were

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recorded at 15-minute intervals.

Data were assembled and retained for final evaluation and analysis by the licensee.

A final leak rate test report will be submitted to the Office of Nuclear Reactor Regulation pursuant to Paragraph V of Appendix J to 10 CFR 50.

b.

Procedure Review Portions of PT 20.5, " Integrated Primary Containment Leak Rate Test",

dated April 27, 1987, were reviewed to verify that test conditions, valve alignments and acceptance criteria were controls, inspector concluded that test conditions and controls test specified.

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were specified in detail in the text; valve alignments and valve restoration were specified in detail in Table 2; and system venting

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and draining was specified in Table 1.

Some minor anomalies relating

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to the test acceptance criteria were identified and resolved with the

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licensee.

The inspector verified that correct acceptance criteria were applied in the test evaluation.

.Since a detailed review of system venting draining and valve alignment for the Type A test was aerformed in 1985 [see IE Report 50-325/85-31 and 50-324/85-31), a cetailed review of these areas was not performed during this inspection.

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An amendment to the license in the area of containment leak rate-testing was issued by NRR on May 12, 1987.

The amendment did not impact t.his test and will be reviewed during future leak rate test inspections.

c.

Containment Integrated Leak Rate (CILRT) Performance - Unit 1(70313)

(1) Method The United Energy Services Cor) oration computer program, used for analysis of the test data, las the ca) ability for Mass Point and Total Time analysis for a minimum 24 lour test or Total Time analysis in accordance with the requirements of BN-TOP-1, Revision'1,1972 for a test duration less than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

The licensee elected to perform the Total Time analysis for a test of less than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> initially with the intent that if BN-TOP-1 criteria were not met, a minimum 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> test using Total Time

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analysis would be performed.

The final test was performed using the BN-TOP-1 Total Time analysis on 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> of test data.

A supplemental test of five hours followed the Type A test.

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

Containment Volume 294981 cubic feet AccidentPressure(Pa)

49 psig % per day MaximumAllowableLeakage(La)

0.5 wt.

System conditions for performance of the integrated leak rate

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test were as follows:

Vented to containment atmosphere:

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Reactor Vessel

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water level at about 210 inches.

RHR System One loop operating in the shutdown

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cooling mode.

Containment Ventilation Fans tripped.

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System Containment Isolation

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Vented, drained, and aligned System per procedure PT 20.5.

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After the structural inspection, the containment was pressurized to 64.6 psia.

The following key events were taken from the test log:

Date Time Event 05/18/87 1320-Containment pressurized to 64.6 psia.

Air pressure secured:

Pressurization line isolated and vented.

1320 started minimum four hour stabilization period.

1730 Temperature stabilization criteria met:

Type A test initiated.

2000 Leak surveys performed:

A few small miscellaneous leakages not considered significant were identified:

One leak considered significant identified through a threaded fitting on the H-0 Post Accident Monitoring System 4kl0. 2 Licensee continuing to observe test behavior to determine if test will pass without repair.

05/19/87 0030 The initial Type A test was terminated and the fitting in the H -02 m nitoring system

was repaired.

0115 Type A test restarted.

0915 Type A test successfully completed per BN-TOP-1 criteria.

lemental test initiated after one hour 1030 Sup)ilization.

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Imposed leakage 4.4 scfm.

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1530 Supplemental test successfully concluded.

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(3) Test Results

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(a) Type A Test The allowable leakage (La) at accident pressure (Pa) for Brunswick Unit 1 is 0.5 wt.%/ day (weight percent per day).

Therefore, the CILRT acceptance limit of 0.75 La as required by Appendix J to 10 CFR 50 is 0.375 wt.%/ day.

Although the official test analysis, method req,uired by Appendix J is the Total Time analysis, the licensee processed the data by both the Total Time and Mass Point analysis methods.

Test results for the eight hour test aeriod,1:15 a.m. to 9:15 a.m., May 19,1987, are shown Jelow in weight percent per day (wt.%/ day).

Leak Rate Mass Point Total Time

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Lam-0.087 0.069 i

95% UCL 0.094 0.205 Based on these results, the Type A test is within the acce tance limit of 0.75 La (0.375 wt.%/ day) for both calc lational methods.

The inspector calculated weighted averages for containment temperature, pressure and vapor pressure using the weichting factors and individual sensor data for a sample of cata sets to verify agreement with the weighted averages and mass calculations generated by the licensee's computer

program.

Subsequently, the mass points generated by the licensee's aro the leak ra;e, gram were used by the inspector to calculate and the 95% upper confidence leak rate.

The inspector's calculations agreed with the licensee's calculations.

(b) Supplemental 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-N45-1972, as follows:

A known 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).

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The acceptance criteria is expressed as:

Lo + Lam - 0.25 La < Lc < Lo + Lam + 0.25 La

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A five hour sup)lemental test was performed by the imposed leak rate methoc described in Appendix C to ANSI-N45.4-1972 and. in accordance with the requirements of BN-TOP-1.

-Rev. 1.

The following values in units of wt.%/ day were obtained using both Mass Point and Total Time analysis.

Mass Point Total Time Lam 0.0868 0.0685 Lo 0.487 0.487 0.25 La 0.125 0.125 Lc 0.5768 0.557 Using these values in the acceptance criteria yields the following:

Mass Point:

0.4488 < Lc < 0.6988 Lc = 0.5768 satisfies the above inequality and therefore, the supplemental test is acceptable.

Total Time:

0.4305 < Lc < 0.6805 Lc = 0.557 satisfies the above inequality and therefore, the supplemental test is acceptable.

The inspector concluded that the "as left" containment leak rate meets the Appendix J and Technical Specification 4.6 i

requirements.

6.

"As-Found" Containment Leakage Rate, Unit 1 I

The control to ensure that any leakage correction to the containment i

boundary prior to the Type A test is identified and measured, has been established in engineering procedure ENP-17, " Pump and Valve Inservice Testing (IST)".

The arocedure incorporates Appendix J valves into the ISI program, identifies

he conditions which will require pre maintenance local leak rate tests (LLRT) and in Table 17-1 specifies the type of testing required for the various conditions.

The, procedure also defined, in general, the calculational method for determining the minimum pathway

leakage and leakage savings.

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The inspector concluded that the licensee has established administrative and procedural controls which will ensure that the "as found" containment overall leak rate can be determined.

The calculations for the "as found" leak rate were not complete at the time of this inspection so a detailed

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inspection of the implementation of the calculational method was not

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performed.

Selected parts of the local leak rate test procedure, PT-20.3 were reviewed to verify that Type B leak rate tests, such as the equipment hatch, were included in the "as found" leak rate calculation.

Type B LLRT procedures which were reviewed included:

PT-20.3.39 Equipment Hatch PT-20.3.40 Personnel Lock to Drywell Liner PT-20.3.41 Drywell Head Blank PT-20.3.42 Drpell Head Access Hatch PT-20.3.43 CRD Hatch PT-20.3.44 South Torus Access Hatch PT-20.3.45 North Torus Access Hatch PT-20.3.46 Drywell to Drywell Head j

The inspector concluded that the "as found" leak rate for Type B components was determined.

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7.

Type A Test Schedule, Units 1 and 2 A review of the integrated leak rate test (CILRT) history for Units 1 and 2 was performed to determine the future test schedule.

The NRC has classified the "as found" leak rate test status as " pass" or " fail" as follows:

IE Report Unit 1 Date Status Number Description 1st Periodic Test 06/81 Failed 81-13 Excessive leakage (1.2%)

through the CAC system required repair.

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2nd Periodic Test 09/85 Passed 85-31

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3rd Periodic Test 5/87 Failed 87-15 Excessive Leak (0.3%) in

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Also unquantified leakage

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corrected prior to test on feedwater penetration.

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IE Report Unit 2 Date Status Number Description 1st Periodic Test 12/77 Failed 77-29 A number of miscellaneous leaks including valves, packing, flanges, and fittings were repaired during the test in order to meet the acceptance limit.

-2nd Periodic Test 07/82 Failed 82-21 Numerous small leakages from valve bonnets, valve packing, connectors, fittings, flanges, and pump seals.

Leaka identified in CS,ge was CAC, CAM, TIP and RHR systems.

The most severe leak was through an RHR relief valve which was missing a gagging bolt (7%).

. Subsequent to the 2nd Periodic Test, Unit 2 was on the refueling outage or 18 month test frequency specified in Paragraph III.A.6.(b) of Appendix J.

3rd Periodic Test 09/84 Failed 84-28 Drain valves on discharge (1stacceleratedtest)

of RHR pump leaked water

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to RHR sump.

Loss of i

water mass was registered

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as a 0.28% air leak by

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CILRT instruments.

NRC will re-evaluate classi-fication.

Leaka cor-rections during ypes B and C testing an during the Type A test must be evaluated to determine the "as found" leak rate.

4th Periodic Test 05/86 Failed 86-14 Excessive leakage through (2nd accelerated test)

the vacuum breaker lines.

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Based on the above classification, the following CILRT schedule is indicated:

Unit 1:

The, licensee must submit a proposed CILRT schedule to NRC for review.

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Unit 2:

Due to successive failures, Unit 2 remains on the refueling outage or 18 month CILRT schedule.

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The licensee stated that the Unit 2 test of 9/84 was considered a passed l

CILRT in that the leakage was water rather than air.

Drain valves on the

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discharge of the RHR pumps were leaking significant amounts of water to i

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the RHR sump.

This loss of water mass from containment was registered as

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air loss by the containment instrument system.

The inspector agrees with the licensee's contention that the intent of j

Appendix J is to measure air leakage from containment and agreed to i

re-evaluate the 9/84 test.

On return to Region II, the inspector reviewed the IE Report and the Integrated Leak Rate Test report related to the 9/84 CILRT on Unit 2.

The inspector concluded that leakage corrections made

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3rior to the Type A test and during the test must be evaluated in detail

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aefore the 9/84 Unit 2 test can be reclassified.

This will require an

onsite inspection utilizing marked-up leak rate test drawings.

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