IR 05000245/1987018
| ML20235J499 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 09/21/1987 |
| From: | Anderson C, Chung J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | |
| Shared Package | |
| ML20235J472 | List: |
| References | |
| 50-245-87-18, NUDOCS 8710010468 | |
| Download: ML20235J499 (12) | |
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U.S. NUCLEAR REGULATORY COMMISSION
REGION I
Report No.
50-245/87-18 Docket No.
50-245 I
License No.
DPR-21 Licensee:
Northeast Nuclear Energy Co.
P. O. Box 270 Hartford, Connecticut 06141-0270
Facility Name: Millstone Nuclear Power Plant, Unit 1
Inspection At: Waterford, Connecticut Inspection Conducted: July _ 31_, 1987 - August 7,_1987 i
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Inspectors:
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r. Jin W.
hung date enior Reactor E ineer Approved by:,'.. J. Anderson, Chidf __
f!2-h7 k.
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it Systems Section i
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l Insp_ection Summary:
Inspection on July 31, 1987_- August 7, 1987 (Inspection No. 50-245/87-18).
Areas Inspected:
Routine unannounced inspection of test witnessing and preliminary results evaluation of Containment Integrated Leak Rate Test (CILRT), and tours of the facility.
Results: No violations or deviations were identified.
8710010468 870923 PDR ADOCK 05000245 O
PDR l
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l-DETAILS l
1.0 Persons Contacted-M.
Bigiarelli, Assistant Test Director, ILRT'
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- G. J. Closure, Plant Quality Services Supervisor
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- E. J. Georgian, ILRT Test Director D, Johnson, IDC B. Loweth, Test Director, ILRT J. Nowell, Shift Supervisor R. Palmieri, Operations Supervisor
- S. E. Scace, Millstone Station Superintendent J. Selvidio, QA
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J. T. Dimarzo, Sr. Engineer W. English, Sr. Engineering Technician N. Herzig, Engineer R. J. Schmidt; Supervisor - Special program's Stone & Webster B. I. Parry The inspector also held discussions with other licensee employees during the inspection, including operations, technical support, and other craft personnel.
- Indicates those present at the exit meeting held August 7, 1987 1.1 Attendees at August 5, 1987 Meeting G. E. Cornelius, NUSCO-GME J. W. Calderone, CY-Engineering E. J. Georgian, NNECO, Millstone 1 Engineering M. D. Hess, NNECO, Millstone 3 M. S. Ledermen, NUSCO - Licensing S. L. Stadnick, NNECO, Millstone ? Engineering J. W. Chung, USNRC, Region I 2.0 Administrative Control of Integrated Leak Rate Test (ILRT)
Several pretest meetings were held with the licensee representatives to discuss the progress of test preparations, the scope of test, and the testing methodology.
The following observations were made:
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Continuous 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> QA coverage was planned
Scheduling and scope of the containment walkdown were evaluated and
discussed.
ILRT valve lineups were in progress.
- Test personnel, including operations, were briefed on " Punch List"
items, critical to the ILRT.
A total of 20 RTDs and 6 Dewcell sensors were placed for the test; 8
RTDs and 2 Dewcells in the Torus, and the rest of the sensors in the i
Drywell.
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In-situ calibration checks were performed prior to the ILRT.
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Control Roorn Halon test (Appendix R test) was performed on
August 2, 1987, prior to the ILRT performance.
General housekeeping and final instrument visual inspections were
conducted by I&C, QA, and test personnel.
Equipment hatch was tested for Local Leak Rate Testing (LLRT) Type C.
- Torus manway was tested for LLRT.
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The inspector interviewed selected licensee personnel and reviewed administrative documents, procedural sign-offs, data collection and the official Type A test-log of events.
The test activities were observed to verify that:
Prerequisites were met; the tast was conducted in
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accordance with the procedure; test directors were designated and their l
responsibilities were defined; and required plant parameters were being recorded during the test.
The inspector noted that the licensee maintained good control of containment and penetration area access before and during the ILRT.
2.1 Documents Reviewed i
l Control Room Log and Shift Supervisor Log.
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Calibration Records:
2 pressure gauges, 2 data acquisition
units, Dewcells, RTDs, and 2 Flow meters for verification test.
Technical Specifications.
- Selected containment penetration valve lineup diagrams.
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Sensor location diagrams.
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i Surveillance Procedure (SP) 623.14, local Leak Rate Test.
- Inservice Test Procedure Change Form, T87-1-6, Change No. 8.
- Quality Activity Observation Report Response Form, No.187-44,
ILRT Procedure Review.
Internal Memo, MP-1-3163, Restricted Access to Unit 1 Reactor
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Building during Test, July 31, 1987 Nuclear Engineering and Operations Procedure, NE0 2.20,
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Containment Leakage Rate Testing Program.
i T 87-1-6, Primary Containment Integrated Leak Rate Test, i
No unacceptable conditions were identified.
3.0 Final Containment Walkdown
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At 10:00 a.m., August 5,1987, the final drywell closecut inspection was
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conducted as required by 10 CFR 50, Appendix J.
The walkdown team included the ILRT Test director, I&C, Operations, QA monitor, and the USNRC inspector.
The following items were observed.
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The necessary tanks and systems were vented per procedures,
including MSIV accumulators.
Containment housekeeping was good: wood scaffolding, and flammable j
materials were removed.
Unvented containers had been vented.
i A sample of ILRT Instrumentation was inspected at location.
- The data acquisition center was inspected.
The data center included
computer harWare and equipment associated with the instrument verification bypass flow test.
The containment pressurization system was inspected.
This consisted
of compressors and chillers.
The containment fans were secured in order to maintain a stable
air.
The rationale for such actions was discussed.
The reactor vessel water level was maintained approximately 30" above
the reactor core.
The CRD system was tripped, and the reactor water level was controlled
with the shutdown cooling system, as needed.
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During the closecut inspection, the licensee's inspection team
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discovered that the personnel airlock seal gaskets were damaged. The l
seals were replaced.
The LLRT was to be performed after the Type A i
test.
Prior to final pressurization of the Drywell and Torus, A QA inspector
checked the air quality from the compressors.
The air quality was acceptable.
l At 4:55 pm, August 5, 1987, the containment pressurization was commenced
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at a rate of 8#/hr.
The licensee secured the compressors at a containment pressure of 10 psig.
In accordance with the test procedure, the penetrations and system lineups were inspected to verify potential leak pathways.
j No unacceptable conditions were identified.
4.0 Containment Integrated Leak Rate Test (CILRT)
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4.1 CILRT Procedure Review
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The inspector reviewed the CILRT test procedure, T 87-1-6, and I
associated procedure changes (Change Nos. I through 8) for adequacy and correctness of the procedure to perform the test.
Procedure, T 87-106, " Primary Containment Integrated Leak Rate Test", included many options and test methodologies, including an 8_ hour reduced
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duration test, the Total Time Calculational method, and the Mass l
point method of ANSI N56.8-1981.
l The licensee selected an 8-hour reduced duration test, employing the Total Time calculational option.
This was consistent with the Bechtel i
Topical Report, BN-TOP-1, Revision 1, " Testing Criteria for Integrated
Leakage Rate Testing of Primary Containment Structures for Nuclear
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Power Plants." The specified acceptance criteria were consistent with those specified in BN-TOP-1.
The "As Found" penalty of 71.4 Standard Cubic Feet per Hour (SCFH) would be subtracted from the normal acceptance value of 375 SCFH (0.75 L,).
The "As Found" penalty j
was based on the Local Leak Rate Test (LLRT) results. The penalty h
would reduce the acceptance criteria.
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The procedure was revised to include provisions which allowed the
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licensee to control the reactor vessel water level using the shutdown
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cooling system should water level adjustment be needed during the test.
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4.2 Test Instrumentation l
The inspector reviewed the calibration records for the ILRT instrumen-tation.
These records indicated that the standards used were traceable
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to the National Bureau of Standards (NBS).
The in-situ calibration i
data and the automatic data acquisition / analysis system were also l
inspected.
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Under BN-TOP-1 recommendations, the ILRT should employ a' minimum of l
12 temperature sensors, at least 6 Dewpoint sensors, and one precision pressure gage.
The following shows a summary of the. sensors used for-the test:
BN-TOP-1 Recommended Sensors Minimum Actual
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20 Dewcell
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Flowmeter
1 Verification Test l
Pressure Guage
2 The latest industrial standard, ANSI N56.8-1981, specifies a minimum of 3 Dew point sensors, and no Drybulb temperature sensor are allowed to represent a volume fraction greater than J0% during the CILRT.
The actual instrumentation for the CILRT exceeded the above ANSI standard specification.
4.3 Failure of "As Found" CILRT The containment pressurization was continued after a 10 psig holding-inspection pause. Containment pressurization was terminated at 7:24 am, August 6,-1987.
The containment pressure reached the accident pressure of 58.6 psia at an average containment temperature of 87.4 F.
The containment stabilization period was commenced immediately, and a 4-hour stabilization period was completed by 11:24 am, meeting the stabilization acceptance criteria as follows:
Criterion-Actual Acceptance Criterion (BN-TOP-1)
Value Result The rate of change of average temperature averaged over the last 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />, F/hr.
. <1.0 0.11 The rate of change of temperature changes averaged over the last 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />, F/hr/hr.
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The actual results presented in the above table were calculated values by the inspector based on the actuel data points analyzed by the data acquisition system.
Individual data points were monitored every 15. minutes.
The raw data points were calculated for the CILRT by the computer.
The official CILRT was commenced immediately following the 4-hours stabilization period.
At 3:29 pm, August 6, 1987, a Service Air penetration was suspected as a leak pathway, and'the leak through
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- 1-SA-516 was quantified as 6.78 SCFH. At 1715 hour0.0198 days <br />0.476 hours <br />0.00284 weeks <br />6.525575e-4 months <br />, another leak was-located in the vent.line from the Isolation Condenser (IC) vent line to the Main Steam (MS) piping, downstream of the MSIV's.
Leaks
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through the IC A0Vs 6 and 7 were identified and quantified as 11.5'
SCFM (690 SCFH). This exceeded the CILRT acceptance criteria of 0.75L L, is 500 SCFH and 0.75L, is 375 SCFH.
The licensee, subsequently, declared the "As Found" CILRT as a failure.
In accordance with.the' requirements specified in III.A.6(2)
of 10CFR50, Appendix J, the above "As Found" failure of the type "A"
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test requires the licensee to submit the next type "A" test schedule.
to the commission for an approval.
4.4 "As left" CILRT Result The CILRT was conducted in accordance with BN-TOP-1 requirements, employing an 8-hour duration test and the Total Time calculational method.
The inspector reviewed the preliminary test results, as shown on the attached figure.
The measured leak rates and 95% upper confidence limit (UCL) values are plotted as a function of time and compared to the acceptance criteria.
In this figure, the measured and the t-statistical points approach asymptotically.
The initial data fluctuation represents the inherent perturbation of the points due to the statistical method employed.
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A final evaluation of the test results will be performed by the NRC l
on receipt of the licensee's summary technical report on the test.
The following summarizes the test results:
Stabilization Period:
1844 hour0.0213 days <br />0.512 hours <br />0.00305 weeks <br />7.01642e-4 months <br /> - 2244' hour, August 7, 1987 f
Actual
0.003 F/hr/hr j
Acceptance Criteria:
0.5 F/hr/hr a
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CILRT:
2244 hour0.026 days <br />0.623 hours <br />0.00371 weeks <br />8.53842e-4 months <br />, August 7, 1987 - 0659 hour0.00763 days <br />0.183 hours <br />0.00109 weeks <br />2.507495e-4 months <br />, August 8, 1987 l
l Total Time Measured:
0.3395 weight %/ Day l
Total Time 95% UCL :
0.400 weight %/ Day I
Acceptance Criteria:
0.900 weight s/ Day l
4.5 ILRT CHRONOLOGY l
l August 2, 1987 j
10:30 - 12:00
- General tours inside Drywell and Torus.
8 RTDs and 2 Dewcells were installed in the Torus.
17:18 17:44
- Control Room Halon test: Appeared to meet the acceptance criteria
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August 3, 1987
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09:00 All 20 RTDs' and' 6 Dewcells are installed.
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situ Calibration. Failed.
16:20
- Pre-closeout containment. inspection performed.
General penetratio'n inspection performed.
l 20:00 Equipment Hatch closed 22:20 I&C and QA made Drywe'll entry for final In-situ Calibration of the ILRT instrumentation.
August 4, 1987 ILRT delayed due to Drywell vessel header alignment problem.
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20:30 Torus manway hatch closed.
Equipment Hatch LLRT l
completed
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21:00 Torus Manway Hatch LLRT completed.
August 5, 1987 j
10:00 Drywell header was successfully placed.
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- Final pre closecut inspection was performed:
l I&C, Operations, QA, ILRT Test' Director, and NRC.
Found Personnel Airlock Gasket damaged.
15:30 Final ILRT Briefing held by Assistant Test I
Director.
16:55
- Air Compressor output air quality checked by QA.
Containment pressurization commenced at a l
rate of 10 psia per hour:
300 cfpm 21:00
- Control Room Narrow Range Reactor Vessel Water level Indicator A shows 54" Water. level, a loss of more than 3" in less than 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> at a j
containment pressure of 10 psig.
l 21:35 Containment pressurization commenced again.
22:55 Drywell Air Pressure,12.5 psig.
'A' Narrow Range Level Indicator 53" l
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August 6 _1987
07:24 Terminated pressurization. Added water via Shutdown Cooling System; ' A' Level Indicator 59"; Air Pressure, 58.6 psia; Average Temperature, 87.4 F. Official Stabilization period commenced.
11:24 Stabilization Criteria was satisfied: 0.1982 F/last 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />; 0.1053 F/hr/last hour.
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- Identified a leak through 2" Service Air System.
r 18:30 Terminated ILRT to quantify the_ leak through IC l
valves 6 and 7:
Leakage rate was greater than i
10.00 SCFM.
(Declared "as-found" Test a failure *)
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18:44 Reinitiated Stabilization Period.
22:44 Completed 4 HR stabilization: 0T =
22:45 Commenced ILRT test
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August 8, 1987 06:59 Completed ILRT:
Total Time ILRT = 0.40 %/ Day 95% UCL.
Least Square Feet ILRT = 0.3395%/ Day Acceptance = 0.90 %/ Day
- Inspector witnessed this activity.
5.0 Local Leak Rate Test (LLRT)
At 1300 hour0.015 days <br />0.361 hours <br />0.00215 weeks <br />4.9465e-4 months <br />, August 5, 1987, the inspector held a meeting with the representatives of Millstone units 1, 2, 3, and Haddam Neck, and NUSCO i
licensing engineer to discuss the Local Leak Rate Testing (LLRT) of some selected containment isolation valves. Attendees of the meeting were listed in section 1.1.
Under the provisions of Appendix J, Type C testing requirements, a reverse direction LLRT was permitted, provided that such reverse direction testing would provide more conservative test results.
However,
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some valves, such as Atmospheric Control valves, could yield less conservative results under the reverse direction test:
the reverse direction test might be more conservative for the valve seat leakages.
However, the valve packing might not be exposed to the pressure under the reverse direction pressurization.
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- The inspector determined that this situation had been recognized by the licensee.
The acceptability of such reverse direction test would be further investigated.
The licensee representative stated that final course of their actions would be conveyed to the NRC by September 1, 1987.
This is an unresolved item, pending final disposition of this item or submittal of an exemption, for the reverse direction test (50-245/87-18-01).
6.0 QA/QC Test Coverage The inspector discussed QA/QC activities during the CILRT and observed various QA activities related to the test preparation, initiation, equipment surveillance, air quality check, and test performance.
Based on the above observation, the inspector determined that the QA surveillance were adequate, and 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> continuous monitoring of the CILRT activities was good.
The inspector also determined that the QA Observation Report was adequate to document the QA activities during the CILRT performance.
No unacceptable conditions, devitiations or violations were observed.
7.0 Plant Tours The inspector made several tours of the plant facilities, including reactor building penetration areas, Drywell, Torus, Control Room, and
plant exterior (compressors, etc.).
The objective of such tours included
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testing activity monitoring, general housekeeping, and administrative controls of the CILRT activities.
The following findings were identified
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during the facility tours:
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The station superintendent entered the Drywell with anti-c,
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protective clothing.
This is an indication of station management attention.
i The interior or the Torus and Drywell were clean and general
housekeeping was good.
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The administrative controls and access controls during the testing
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were adequate.
General housekeeping near the mechanical and electrical penetration
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areas were adequate.
No unacceptable conditions were identifie _ _ _ _ _ _ - _ _
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8.0 Exit Meeting Licensee management was informed of the purpose.and scope of the inspection at the entrance interview.
The findings of the inspection were periodically discussed and were summarized at the exit meeting on August 17, 1987.
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Attendees at the exit. meeting are listed in section 1.0 of this report.
j At no time during the inspection was written material provided to the
licensee by the inspectors.
l The licensee representatives indicated that no proprietary information was involved within the scope of this inspection.
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