IR 05000483/1987008

Insp Rept 50-483/87-08 on 870226-0428.Violations Noted: Fuel Pool Cooling & Cleanup Vent Valve EC-V082 Found in Closed Position Contrary to Procedures

ML20214R022
Person / Time
Site:	Callaway
Issue date:	05/26/1987
From:	Maura F, Wright G NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
To:
Shared Package
ML20214R009	List: IR 05000483/1987008 ML20214R006 ML20214R012
References
50-483-87-08, 50-483-87-8, NUDOCS 8706050298
Download: ML20214R022 (10)

Text

{{#Wiki_filter:. _ . _ . _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ - _ _ _ _ _ _ _ _ _ _ _ -

. .

U.S. NUCLEAR REGULATORY COMMISSION

REGION III

Report No. 50-483/87008(DRS) Docket No. 50-483 License No. NPF-30 Licensee: The Union Electric Company Post Office Box 149 St. Louis, M0 63165 Facility Name: Callaway, Unit 1 Inspection At: Callaway Site, Callaway County, Missouri and

         '

Region III Office, Glen Ellyn, IL Inspection Conducted: February 26 through April 28, 1987 Inspector: .A [[2[e!f7

     '

Date Approved By: h YM G. C Wrig' , Chief [/2(,[97 Test Programs Section Date

     '

Inspection Summary, Inspection on February 26 tnrough April 28, 1987 (Report No. 50-483/87008(DRS)) Areas Inspected: Routine announced inspection by Region based inspector of the containment leak rate test (CILRT) procedure, CILRT performance witnessing, and review of CILRT results. NRC modules utilized during this inspection include 70307, 70313, 7032 Results: Of the three areas inspected no violations or deviations were identified in two areas. One violation, with no safety significance, was identified in the remaining area (failure to follow procedure - Paragraph 3.c).

r

  -

8706050298 870529 PDR ADOCK 05000483 G PDR -

. .

DETAILS 7 Persons Contacted

*S. Able, Engineer (Test Director)
*D. Bettenhausen, Supervising Engineer
+*T. DeVincentic, Engineer (Test Coordinator)

D. Fitzgerald, Operating Supervisor

+*P. Godt, QA Engineer
*0. Heinlein, Assistant Superintendent Operations
*R. Huber, Supervising Engineer R., Lamb, Shift Supervision
"J. Laux, Superintendent Technical Support
+C. Lees,-Engineer (Test Coordinator)
-+*T. McFarland, Suparintendent Design Control
*J. Peevy, Assistant Manager, Technial Services
*G. Randolph, General Manager, Nuclear Operations
+D. Shafer, Supervising Engineer, Licensing Bechtel Corporation
*B. Patel, Engineer L. Young, Engineer Wolf Creek Nuclear Station
*A. Birzer, Engineer US NRC
*B. Little, SRI C. Brown, RI l * Denotes persons attending the Region III meeting of February 26, 198 ' Denotes persons attending the exit meeting of April 28, 198 The inspector also contacted other licensee personnel including members of the technical, operating and quality assurance staf . Containment Integrated Leak Rate Test Procedure Review Procedure Review During February 1987 the inspector reviewed a draft of Engineering !

Surveillance Procedure No. ESP-GP-01007, " Reactor Builning Integrated I Leak Rate Test," relative to the requirements of 10 CFR 50, Appendix J, ANSI N45.4-1972, and the Technical Specifications. At the licensee's request a meeting was held on February 26, 1987, at the Region III

.

 .  .

office to discuss the licensee's plans for the Spring 1987 CILRT, regulatory requirements regarding the performance of CILRTs, and the inspector's comments generated during his review of the draft CILRT procedure. All inspector comments were satisfactorily resolved as noted by the review of ESP-GP-01007, Revision 1, dated April 7, 1987 prior to the performance of the tes Clarifications of Appendix J Reauirements To ensure the licensee's understanding of Appendix J requirements, the inspector conducted numerous discussions with licensee personnel prior to an.d during the course of the inspection. The following is a summary of the clarifications discussed with the license (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 error 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 with Bechtel Corp. Topical Report BN-TOP-1, Revision Whenever this method is used BN-TOP-1 must be followed in its entirety except for any section which conflicts with Appendix J requirement (b) Total time (>24 hour duration test) using single sided 95%

UC (c) Proposed Regulatory Guide MS 021-o, Regulatory Position 1 ' 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 Specification (2) Periodic Type A, B, and C tests must include as-found results I as well as as-left. If Type B and C tests are conducted prior ' to a Type A the as-found condition of the containment must be l calculated by adding any improvements in leakage rates, which , are the results of repairs and adjustments (RA), to the Type A l test results using the " minimum pathway leakage" methodolog l This method requires that: j '

     (a) In the case where individual leak rates are assigned to two valves in series (both before and after the RA), the penetration through leakage would simply be the smaller of the two valves' leak rate _ _ _ _ . _ _ _ - _ _ _ _ _ _ _ _ - _ _ _ _ _ _ _ _ _ _ _ _ - _ _ _ _ _ _ _ _ ___ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __ . - _ _ _ _ _ _ _ _ .

.

. .     .
(b) In the case where a leak rate is obtained by pressurizing between two isolation valves and the individual valve's leak rate is not quantified, the_as-found and as-left penetration through-leakage for each valve would be 50% of the measured leak rate if both valves are repaire (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 conservatively be the final measured Icak rate, and the as-left penetration through leak rate would be zero (this assumes the repaired valve leaks zero).

(3) Penetrations which are required to be Type C tested, as described in the FSAR and SER, 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 pressur The degree of draining of vented penetrations outside-of containment is controlled by the requirement that the valves be subjected to the post-accident differential pressure, or proof that the system was built to stringent quality assurance standards comparable to those required for a seismic syste (4) Whenever penetration configurations during a CILRT deviate from the ideal, the results of LLRTs for such penetrations must be added as a penalty to the CILRT results at the 95% confidence level. This penetration leakage penalty is determined using the " minimum pathway leakage" methodology. This methodology is defined as the minimum leakage value that can be quantified through a penetration leakage path (e.g., the smallest leakage through two valves in series). This assurnes no single active failure of redundant leakage barriers. Additionally, any increase in contair. ment sump, fuel pool, reactor water, or suppression pool level during the course of the CILRT must be taken as a penalty to the CILRT result If penalties exist, they must be added (subtraction is never permitted) to the upper confidence level of the CILRT result:,.

(5) The start of a CILRT must be noted in the test log at the time the licensee determines that the containment stabili?ation 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 mad l This also implies that the licensee has determined that the test has failed, and has enough data to quantify the leakage rat Any deviation from these positions should be discussed, and documented, with the NRC inspector as they occur to avoid later invalidations of the test result Examples of acceptable

. . deviatiors of reinitializing the start time of the tett 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 ope (6) 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 begi (7) For the supplemental test, the size of the superimposed leak rate must be between 0.75 and 1.25 time the maximum allowable leak rate La. The higher the valve, the better. The

      '

supplemental test must be of sufficient duration to demonstrate the accuracy of the test. The NRC looks for the results to stabilize within the acceptance criteria, rather than the results being within the acceptance criteria. Whenever the BN-TOP-1 methodology is being used, the length of the supplemental test cannot be less than approximately one-half the length of the CILR (8) During a CILRT, it may become necessary to reject or delete specific sensors or data points due to drifting or erroneous sensors, or data outliers. Data rejection criteria should be developed and used so that there is a consistent, technical basis for data rejectio One example of an acceptable method for data outliers is described in an Appendix to ANSI /ANS 56.8-198 Sensor data rejection criteria should be plant specific and bcsed upon a sensor's trend relative to the average scatter, slope and/or absolute output of the senso (9) The water level in the steam generators during the CILRT must be low enough to ensure it does not enter the main steam lines unless flooding of the main steam lines is called for in the loss of coolant emergency procedur (10) An acceptable method for determining if the sum of Type B and C tests exceeds the 0.60 La Appendix J limit is to utilize the

 " maximum pathway leakage" metho This methodology is defined as the maximum leakage value that can be quantified through a penetration leakage path (e.g., the larger, not total, leakage of two valves in series). This assumes a single active failure to the better of two leakage barriers in series when performing Type B or C test l l

s

      !
. _ _ _ _ _ _ _ _

. .

(11) Test connections must be administratively controlled to ensure their leak tightness or otherwise be subject to Type C testin One way to ensure their leak tightness is to cap, with a good seal, the test connection after its us Proper administrative controls should ensure valve closure and cap reinstallation within the local leak rate testing procedure, and with a check)ist prior to unit restar (12) Whenever a valve is replaced, repaired, or repacked during an outage for which Type A, B, and/or C surveillance testing was scheduled, local leak rate testing for the as-found as well as the as-left condition must be performed on that penetratio 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 sit No violations or deviations were identifie . Contair.mont Integrated Leak Rate Test Witnessing 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 t.s required. The following instrumentation was used throughout the test: Type Quantity RTDs 24 Humidity 6 Pressure gauges 2 Flowmeters 2 T_emperature Survey The licensee conducted a temperature / humidity survey on April 26, 1987 in accordance with Engineering Surveillance Procedure ETP-GP-ST001. The inspector reviewed the results and poted that while the containment showed a very small temperature gradient (~4 F) over the 186 feet height surveyed, only one reading per : subsolume was taken. The inspector discussed with the licensee l the need for additional readings, to be taken prior to the next l Type A test, within each subvolume (when physically possible) to verify each sensor is representative of its subvolume. This is an Open Item (438/87008-01) pending licensee performance of the new , survey and review by the inspecto l l l l

l

. c. Witness of Test The inspector witnessed portions of the CILRT on April 27-28, 1987-and noted that test prerequisites were met and that the appropriate revision to the surveillance procedure was followed by test personne Valve lineup for the following systems were verified correct to insure that no fluid cou?d enter the containment atmosphere and that proper venting and draining was provide System P_enetration(s) Chemical and Volume Control 23, 80 Reactor Makeup Water Supply 25 Compressed Air 30 Auxiliary Steam Decontamination 43 Accumulator Nitrogen 45 Fuel Pool Cooling and Cleanup 53 Accumulator Fill Line (HPCI) 58 Pressurizer Relief Tank 62 Service Air 63 Component Cooling Water 75 Breathing Air 98 Containment Purge 160, 161 During the valve lineup verification the inspector found fuel pool cooling and cleanup system vent valve EC-V082 closed instead of open as required by Test Procedure No. ESP-GP-01007, Revision 1. A review of the valve lineup checklist (Pages 41 and 42 of Appendix 8 to ESP-GP-01007) covering valve EC-V082 indicated the valve had been opened on April 21 and verified open on April 22. The valve.provides the vent path upstream of containment isolation valve EC-V083 (Penetration No. 53) required during the CILRT. Failure follow Procedure ESP-GP-01007, Revision 1 is a violation (438/87008-02) of Technical Specification Section 6.8.1.a. Following the identification of this violation by the inspector the licensee opened the valve immediately and reverified that all vents located in the auxiliary building were positioned in accordance with the requirements of CILRT Procedure No. ESP-GP-01007, Revision In addition, during the restoration phase following completion of the CILRT, the licensee reverified that all valves had been in the correct position throughout the test. The inspector determined that the licensee took adequate corrective action with regards to the valve position portion of the violation; however, the issue of the second verification apparently incorrectly verifying the valves position is still outstandin d. Liner Weld Channels The Callaway containment liner has 41 weld channels. The CILRT was performed with 23 of the channels vented and 18 not vented. The latter was due to the inaccessibility of the vent plug The licensee was informed that they must submit to NRR their

. .

justification for not venting all liner weld channels during the performance of the CILRT. This is an Open Item (483/87008-03) pending licensee submittal to NRR and NRR's response to the submitta . Test Results Evaluation CILRT Data Evaluation A 24.25 hour CILRT was performed during April 27-28, 1987, at 63.8 psia following satisfactory completion of the required temperature stabilization period. Data was collected every 15 minute The inspector independently monitored and evaluated leak rate data using total time (ANSI N45.4-1972) formulas to verify the licensee's calculations of the leak rate and instrument performanc There was good agreement between the inspector's and licensee's results as indicated by the following summary (units are in weight percent per day).

Measurement Licensee Inspector Leak rate measured during cit.RT (Lam) 0.014 0.014 Lam at upper 95% confideace level 0.038 0.037 Appendix J acceptance criteria at 95% UCL: <0.75La=<0.150 weight percent per day, Supplemental Test Data Evaluation After the satisfactory completion of the CILRT a known leakage rate (based on inspector's independent readings and calculations) of 1 scfm, equivalent to 0.202 weight percent per day was induced. Data was collected and analyzed by the licensee every 15 minutes. The inspector independently monitored and evaluaved leak rate data to verify the licensee's result After 6.25 hours the supplemental test was terminated with satisfactory results as indicated by the following summary (units are in weight percent per day).

M_easurement Licensee Inspec. tor Measured leakage rate, Lc, during supplemental test 0.213 0.214 Induced leakage rate, to 0.199 0.202 Lc-(Lo+ Lam) 0.000 -0.002 i Appendix J acceptance criteria: -0.050 $,[Lc-(Lo+ Lam)] ,<+0.050

     ,

. . c. CILRT Valve Lineup Penalties Due to valve configurations which deviated from the ideal penetration valve Ifneup 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 Per.etration (Units are in SCCM) _ _ _ _ Reactor coolant pump seal water injection (#22, 39, 40, and 41) 284 Fuel transfer canal

     '

Essential service water (#71, 73) 7455 Fire Protection (FS7) 2468 Type A test penetraticns (#34, 51) 1615 RHR recirc sump sample line (#1.4, 15) 22 11,864

   = 0.006 wt. %/ day After taking these local penalties into account, the upper confidence value for containment leakage is equal to 0.044 weight porcent per day, well within the acceptable value of
<0.15 d. As-Found Condition of CILRT The as-found condition is the condition of the containment at the beginning of the outage prior to any repairs or adjustments to the containment boundary. The inzpector reviewed the licensee's summary of the containinent penetratinn local leak rate tests (Type B and C)

performed prior to the CILRT in order to determine the amount of leakage rate improvement due to repairs and adjustments. Based on the results reviewed it was determined that the amount of leakage improvement prior to the CILRT equaled 82,573 sccm, or the equivalent of 0.039 wt%/ day. The ar-foiand CILRT results for the containment was 0.083 wt%/ day which is within the allowable limit of <0.15 .. . The major contributor to the leakage rate improveraent prior to the CILRT was the repair of the A steam generator handhole. A review of the problem shaned that steam generators A and D first experienced handhole leakage during 198 At first the licensee's corrective action consisteu of retorquing the bolts. Later the licensee injected Furranito into the gasket area (on August 1987 and October 6, 1986 for steam ganerator D and on July 28, 1986 and January 30, 1987 for steam generaior A). By March 11 the A steam generator handho'le was leaking again and its leakage rate was measured by the licensee to be 57,800 sccm prior to its repair during the outage. Region III has requested a generic position from NRR regarding steam generator's leakage through toe secondary side and will infor:n the Nicensee of the results when they are receive No violations or deviations were identifie . 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 bot Open items disclosed during the inspection are discussed in Paragraphs 3.b and . Exit Interview l The inspector met with licensee representatives (denoted in Paragraph 1) on April 28, 1987 at the conclusion of the inspection. The inspector summarized the scope and findings of the inspection. The licensee acknowledged the information and did not indicate that any of the information disclosed during the int.pection could be considered

picprietary in nature.

l l l ,

l }}