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Insp Rept 50-461/86-66 on 861027-1211.No Violations or Deviations Noted.Major Areas Inspected:Containment Integrated Leak Rate Test (Cilrt) Procedure,Cilrt Procedure Witnessing & Licensee Actions on Previous Insp Findings
	ML20207H594
Person / Time
Site:	Clinton
Issue date:	12/30/1986
From:	Maura F, Mendez R, Ring M; NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
To:	;
Shared Package
ML20207H589	List: IR 05000461/1986066; ML20207H585;
References
	50-461-86-66, NUDOCS 8701070570
	Download: ML20207H594 (11)
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U.S. NUCLEAR REGULATORY COMMISSION

REGION III

Report No. 50-461/86066(DRS)

DocLet No. 50-461 License No. NPF-55 Licensee:

Illinois Power Company 500 South 27th Street Decatur, IL 62525 Facility Name: Clinton Nuclear Power Station, Unit 1 Inspection At: Clinton Site, Clinton, Illinois Inspection Conducted: October 27 through December 11, 1986 f %,u/4,

Inspectors:

F. Maura

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Date k. "2%,d'c -

R. Mendez

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Date Oh.d b

(b t2.[>o/ 6 Approved By:

M. Ring, Chief Test Programs Section Date l

Inspection Summary Inspection on October 27 through December 11, 1986 (Report No. 50-461/86066(DRS))

Areas Inspected: Routine, announced inspection by Region based inspectors of the containment integrated leak rate test (CILRT) procedure; CILRT performance witnessing; review of CILRT results, and review of licensee action on previous inspection findings.

NRC modules utilized during this inspection include 70307, 70313, 70323, 92701 and 92702.

Results: No violations or deviations were identified.

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DETAILS 1.

Persons Contacted

- J. Brownell, Licersing Specialist L. Cox, Test Coordinator

D. Hall, Vice President K. Hedquist, Test Coordinacor D. Holesinger, Nuclear Safety Director W. Koehler, Valve Lineup Coordinator

- J. Miller, Director Startup Testing

J. Peterson, Supervising Engineer, Licensing

- S. Silverman, Test Director

F. Spangenberg, Manager Licensing and Safety

D. Wilson, Licensing Engineer

- J. Weaver, Director of Licensing Bechtel Corporation B. Patel, Engineering Specialist R. Blum, Engineering Specialist

Denotes persons attending the exit meeting of November 4, 1986.

- Denotes persons participating in the telephone exit interview of December 11, 1986.

The inspectors also contacted other licensee personnel including members of the technical, operating and quality assurance staff.

2.

Licensee Action on Previous Inspection Findings Closed (0 pen Item) 461/85060-01(DRS): CILRT procedure did not require the trending of sensors threaghout the test when using the Bechtel Topical Report BN-TOP-1 methodology of testirg. The inspector reviewed

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CPS Procedure No. 9861.01, Revision 20 and noted that Step 8.3.2 requires

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the trending of sensors at 15 intervals.

l Closed (0 pen Item) 461/85060-02(DRS):

CILRT procedures did not require

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that the length of the verification test be at least approximately half the length of the Type A test when using the methodology of testing described in BN-TOP-1. The inspector reviewed CPS Procedure No. 9861.01, Revision 20 and noted that Step 9.1.4.2 requires that the length of the verification test, for a short duration Type A test, (BN-TOP-1) be no

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Closed (Deviation) 461/85060-03(DRS):

Failure to perform a 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months Type A test in accordance with the FSAR commitment to ANSI N45.4. The licensee revised the FSAR on January 1986 (Amendment 36) to include the requirements of Bechtel's Topical Report BN-TOP-1, Revision 1 as one of the controlling documents. Using the methodology of BN-TOP-1, Revision 1, which is an NRC approved document, the licensee may perform Type A test of <24 hours duration.

Closed (Violation) 461/85060-04c and b(DRS):

Licensee's failure to control activities affecting quality.

The inspector reviewed the controls in effect at the time of the CILRT and found them satisfactory.

Construction work in the containment building is now complete.

Closed (Unresolved Item) 461/85060-05(DRS): Due to the number of modifications performed on the containment liner and the apparent lack of work and access control a Type A test was required to guarantee containment integrity following completion of all the containment work.

The licensee performed a Type A test in November 1986 following completion of all containment liner work and the establishment of access control into the containment per CPS Procedure No. 1032.02. This test is considered by the licensee to be its initial test prior to the requirement of containment integrity. As such, no as found test results are considered necessary since this test replaces the original preoperational CILRT.

3.

Containment Integrated Leak Rate Test Procedure Review a.

Procedure Review The inspector reviewed surveillance Procedure CPS No. 9861.01, Revision 20, relative to the requirements of 10 CFR 50, Appendix J, ANSI N 45.4-1972, and the FSAR. The following problems were identified:

(1) During the valve lineup review the inspector noted that Valve IE51-F068 was required to be closed for the CILRT.

Valve F068 is a normally open, motor operated valve in the RCIC turbine steam exhaust line to the suppression pool.

The valve receives no automatic isolation signal. According to the licensee, the CILRT valve lineup procedure required Valve F068 closed because of Table 6.2.47 of the FSAR. After reviewing the RCIC exhaust line isolation valves' design and Table 6.2.47 with NRR (J. Kudrick) the licensee was informed that the FSAR Table 6.2.47 was in error and should be corrected at the next amendment submittal. The table should show that Valve F068 is to remain open during the Type A test so that Valve F040 is the containment boundary, and that both Valves F040 and F068 will be Type C tested. The licensee was also informed that the CILRT procedure must be revised to reflect the correct valve configuration. This is an Open Item (461/86066-01) pending completion of the CILRT procedure revision and correction to FSAR Table 6.2-47.

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(2) During the valve lineup review the inspector noted that the licensee was using Motor Operated Valves 1821-F065A and B as isolation boundaries outside containment on the feedwater penetrations. Both valves are normally open and lack an automatic isolation signal. The licensee was informed that no containment boundary credit can be taken during the CILRT for either valve. The licensee decided to leave the valves closed for the test and take a penalty (minimum pathway leakage measured during Type C test of the feedwater check valves) for each penetration. The resolution meets Appendix J requirements.

(3) The procedure cells for all the liner leak chase channel plugs to be removed for the test and not be replaced. The inspector questioned the licensee regarding long term corrosion of the unpainted liner surface behind the channels, if the plugs are not reinstalled.

In addition, if the plugs are reinstalled and not removed for future CILRTs, the licensee must submit to NRR their justification for using the leak chase channels and welds as the new containment boundary.

During a telephone conversation on December 4, 1986, the inspector was informed that an analysis has been performed which determined that the corrosion generated with the plugs removed is insignificant.

The licensee has decided to leave the plugs removed. This is An Open Item (461/86066-02) pending NRC's review of the licensee's analysis.

b.

Classification of Appendix J Requirements To ensure the licensee's understanding of Appendix J requirements, the inspectors conducted numerous discussions with licensee personnel during the course of the inspection. The following is a summary of the clarifications discussed with the licensee. The licensee agreed to revise the CILRT procedure where needed to agree with these clarifications.

(1) The only methods of data reduction acceptable to the NRC are total time or point-to point as described in ANSI N45.4-1972 including a statistically calculated instrument analysis.

The following options are available to the licensee and are suggested in the following order:

(a) total time (<24 hour duration test) in accordance in the Bechtel Corp. Topical Report BN-TOP-1, Revision 1.

Whenever this method is used, BN-TOP-1 must be followed in its entirety except for any section which conflicts with Appendix J requirements.

(b) total time (24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months duration test) using single sided 95*4 UCL

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(c) Proposed Regulatory Guide MS 021-5, Regulatory Position No. 13.

If this method is utilized the licensee must submit an exemption request to NRC and receive approval for its use prior to the expiration of the Type A test frequency requirements stated in the Technical Specifications.

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(2) Periodic Type A, B and C tests must include as-found results as well as as-left.

In order to perform Type B and C tests prior to a Type A an exemption from the Appendix J requirement must be obtained from NRR. The exemption request must state how the licensee plans to determine the as-found condition of the containment since local leak rate tests are being performed ahead of the CILRT. An acceptable method is to commit to add any improvements in leakage rates, which are the results of repairs and adjustments (R&A), to the Type A test results using the " minimum pathway leakage" methodology. This method requires that:

(a) In the case where individual leak rates are assigned to two valves in series (both before and after the R&A), the penetration through leakage would simply be the smaller of the two valves' leak rates.

(b) In the case where a leak rate is obtained by pressurizing between two isolation valves and the individual valves'

leak rate is not quantified, the as-found and as-left penetration through-leakage for each valve would be 50 percent of the measured leak rate if both valves are repaired.

(c) In the case where a leak rate is obtained by pressurizing between two isolation valves and only one valve is repaired, the as-found penetration leak rate would

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conservatively be the final measured leak rate, and the as-left penetration through leak rate wou'

zero(this assumes the repaired valve leaks zero).

(3) Penetrations which are required to be Type C tested, as described in the FSAR and.0ER, must be vented inside and outside the containment during the CILRT. All vented penetrations must be drained of water inside the containment and between the penetration valves to assure exposure of the containment isolation valves to containment air test pressure.

The degree of draining of vented penetrations cytside of containment is controlled by the requirement the.t the valves be subjected to the post-accident differential pressure, or proof that the system was built to stringent ouality assurance standards comparable to those required for a seismic system.

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'(4) The start of a CILRT must be noted in the test log at the time the licensee determines that the containment stabilization has been satisfactorily completed.

Reinitializing a test in progress must be " forward looking," that is, the new start time-must be the time at which the decision to restart is made.

This also implies that the licensee has determined that the test has failed, and has enough data to quantify the leakage rate. -Any deviation from these positions should be discussed, and documented, with the NRC inspector as they occur to avoid later invalidations of the test results.

Examples of acceptable deviations of reinitializing the start time of the test in the past are:

time at which a leaking penetration which has an obvious effect on the test data was secured, accidental opening and later closing of a valve which has an obvious effect on the test data, the time at which an airlock.

outer door was closed and the inner door was open.

(b) The supplemental or verification test should start within one hour after the completion of the CILRT.

If problems are encountered in the start of the supplemental test, data recording must continue and be considered part of the CILRT until the problems are corrected and the supplemental test can begin.

(6) Test connections must be administrative 1y controlled to ensure their leak tightness or otherwise be subject to Type C testing. One way to ensure their leak tightness is to cap,

. with a good seal, the test connection after its use.

Proper administrative controls should ensure valve closure and cap re-installation within the local leak rate testing procedure, and with a checklist prior to unit restart.

(7) Whenever a valve is replaced, repaired or repacked during an outage for which Type A, B, and/or C surveillance testirg was scheduled, local leak rate testing for the as-found as well as the as-left condition must be performed on that penetration.

In the case'of a replaced valve, the as-found test can be waived if no other containment isolation valve of similar design exists at the site.

No violations or deviations were identified.

4.

Containment Integrated Leak Rate Test Witnessing a.

Instrumentation The inspector reviewed the calibration data and determined all the instruments used in the CILRT had been properly calibrated and that the correct weighting factors had been placed in the computer program as required. The following instrumentation was used throughout the test:

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Type Quantity RTDs

Humidity

Pressure Gauges

Flowmeter

Although one humidity sensor acted erratically several times during the test no sensor or data sets were rejected during the test.

b.

Temperature Survey The licensee conducted a temperature humidity survey on November 1, 1986, just prior to the CILRT. The inspector reviewed the data submitted by the licensee on December 10, 1986 and noted two readings at Elevation 760' (azimuths 355 and 0 ) which differed from the CILRT nearest sensors (Nos. 14 and 16) by approximately 5 F.

The licensee indicated that the location was the Main Steam Tunnel Room and that the reason the temperature deviated so much was that the room doors had remained closed for several days prior to the temperature survey. The licensee stated that the two doors of the room were wired open following the survey and the room temperature should have equalized to the building temperature by the time the CILRT was performed on November 3.

Since the room in question had no temperature sensor during the test, this could not be verified.

The RWCU heat exchanger (HX) room had a similar problem of being cooler than the rest of the containment by approximately 10 F.

However, this room was monitored by a temperature sensor throughout the CILRT (RTD No.10).

The inspector used the temperature change (0.54F ) measured in the RWCU HX room throughout the CILRT and applied that change to the Main Steam Tunnel Room to calculate the possible masking of containment leakage rate which the ummonitored i

Main Steam Tunnel Room could have contributed during the test.

This " masking" of actual leakage rate amountea to 0.027 weight percent one day. This amount has been added to the leakage rate j

results presented in Paragraph 5.a.

During the December 11, 1986 telephone exit interview the licensee was informed of our review of the temperature survey data and the fact that it indicates the need for having a temperature sensor in the Main Steam Tunnel Room.

In addition, the licensee was advised to review the containment configuration to ensure that possible l

encic sed subvolumes are monitored for temperature during further tests. One such area is the cavity between the reactor vessel and

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the biological shield. This is an Open Item (461/86066-03) pending I

review of the licensee's location of temperature sensors and the results of the temperature survey to be performed prior to the next C I '.RT.

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c.

Witness of Test

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The inspector witr.essed portions of the CILRT on November 3-4, 1986 and noted that test prerequisites were met and that the appropriate revision to the surveillance procedure was followed by test personnel.

Valve lineup for the following systems were verified correct to ensure that no fluid could enter the containment atmosphere and that proper venting and draining was provided.

System Penetrations Containment Monitoring IMC-153,173 Feedwater IMC-9, 10 Service Air IMC-59 Instrument Air IMC-57, 58, 206 Drywell Purge IMC-102 RCIC IMC-41, 42, 44 Containment Building HVAC IMC-101, 106, 113, 165, A, B and C Breathing Air IMC-49 In addition, all control rod drive HCU accumulators, MSIV accumulators, and safety / relief valves accumulators were verified to be depressurized.

5.

Test Results Evaluation a.

CILRT Data Calculation A short duration (9 hour1.041667e-4 days 0.0025 hours 1.488095e-5 weeks 3.4245e-6 months ) CILRT was performed during November 3-4, 1986, at 23.7 psia, following satisfactory completion of the required temperature stabilization period. Data was collected and analyzed every 15 minutes. The inspector independently monitored and evaluated leak rate test data using BN-TOP-1, Revision 1, total time formulas to verify the licensee's calculations of the leak and instrument performance. There was excellent agreement between the inspector's and licensee's results as indicated by the following summary (units are in weight percent per day).

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Measurement Licensee Inspector *

Leak rate measured 0.255 0.279 during ILRT (Lam)

Lam at upper 95%

0.286 0.312 confidence level

Includes penalty for Main Steam Tunnel Room heatup during test (see Pr.ragraph 4.b).

Appendix J acceptance criteria at 95 UCL <0.75La <0.488 weight percent per day.

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Supplemental Test Data Evaluation After the satisfactory of the nine hour CILRT a known leakage rate (based on inspector's independent readings and calculations) of 13.1 scfm, equivalent to 0.660 weight percent per day was induced.

Data was collected and analyzed by the licensee every 15 minutes.

The inspector independently monitored and evaluated leak rate data to verify the licensee's results. After 4.5 hours5.787037e-5 days 0.00139 hours 8.267196e-6 weeks 1.9025e-6 months the supplemental test was terminated with satisfactory results as indicated by the following summary (units are in weight percent per day).

Measurement Licensee Inspector Measured leakage rate, Lc, 0.854 0.854 during supplemental test Induced leakage rate, Lo 0.650 0.660 Lc - (Lo + Lam)

-0.0 51-0.0 85 Appendix J acceptance criteria = -0.163 5 [Lc - (Lo + Lam)] 5 + 0.163 c.

CILRT Valve Lineup Penalties Due to valve configurations which deviated from the ideal penetration valve lineup requirements for the CILRT, the results of local leak rate tests for such penetrations must be added as a penalty to Lam at the 95% UCL. The following penalties must be added using the minimum pathway leakage method:

Local Leak Rate Test Value Penetration (Units are in SCCM)

17-RHR LPCI C Injection

10 35-HPCS Injection

10 36-LPCS Injection 70 i 10 152(1)-ILRT Instrumentation 62 1 2 152(2)-ILRT Instrumentation 30 i 2 152(3)-ILRT Instrumentation 37 1 2 67 - Configuration Pressurization

9 - Feedwater A 70 i 10 10 - Feedwater B 80 1 20

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63 - CRD 760 1 22 210 - PASS Reactor Sample 2i2 1191

Local leak rate test had not been performed yet on this penetration as of December 4, 1986.

After taking these local penalties into account, the upper confidence value for containment leakage is equal to 0.314 weight percent per day, well within the acceptable value of 0.488. While the penalty for Penetration No. 67 has not been determined to date

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it is not anticipated that it will have a marked effect on the containment leakage rate. However, it is the licensee's

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responsibility to ensure the results of the local leak rate test on Penetration No. 67 do not cause the containment to leak in excess of the allowable at the time containment integrity is required.

No violation or deviations were identified.

6.

Main Steam Line Guard Pipe Plugs During the inspection it was found that each MSL guard pipe has a 3/4" to 1" threaded pipe plug which is exposed to accident atmosphere. The plugs are not seal welded or tack welded. According to the licensee the use of these plugs meet the requirements of the ASME Code for clcsures on penetration of two inch pipe size or less, and there are no regulations prohibiting the use of threaded closures. The inspector informed the licensee that while the regulations do not prohibit the use of threaded closures it has been our experience that threaded closures have been found removed for unknown reasons at other sites. Therefore, we recommend that positive controls such as seal or tack welding be taken to guarantee the integrity of the containment boundary. During a telephone conversation on December 4, 1986, the inspector was informed that the four plugs had been staked as agreed during discussions with NRR.

During the telephone exit interview of December 11, the licensee was informed that while NRR agreed to the staking of the four plugs it is the licensee's responsibility to ensure that the method used (seal welding, tack welding or staking) guarantees the plugs remain in place.

No violations or deviations were identified.

7.

Containment Airlock Prior to the start of the CILRT, the licensee experienced difficulty with the 828 elevation airlock shaft seals leaking excessively. A record review showed the airlock had successfully passed its last Type B test on'

September 13, 1986. The inspector requested that the licensee not just repair the failed components, but that it investigate and determine the cause of the premature failures experienced with the shaft seals in order to ensure that the corrective action taken is effective.

The licensee informed the inspector on December 11, 1986 that they had reviewed the problem with the containment airlock shaft seals and had determined that:

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They had the latest CBI upgraded type teflon seals at Clinton, and b.

the problem experienced was due to incorrect re-assembly of the shaft seals and the shaft coupling. This caused misalignment induced wear in both the shaft and seal assembly. The licensee indicated that the SWEC Maintenance personnel are now aware of the correct installation procedures.

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Open Items Open Items are matters which have been discussed with the licensee, which will be reviewed further by the inspector, and which involve some action on the part of the NRC or licensee or both. Open Items disclosed during this inspection are discussed in Paragraph 3.a.(1) and 3.a.(3).

9.

Exit Interview The inspector met with licensee representatives (denoted in Paragraph 1)

on November 4, 1986, and by telephone on December 11, 1986 at the conclusion of the inspection. The inspector summarized the scope and

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findings of the inspection. The licensee acknowledged the information and did not indicate that any of the information disclosed during the inspection could be considered proprietary in nature.

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IR 05000461/1986066

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REGION III

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