05000338/LER-1997-005-01, :on 970519,determined That eddy-current Testing Results Did Not Match Signatures Reported During Preservice Baseline Testing,Due to Personnel Error.Verified Current Signatures on Duplicate eddy-current Testing
| ML20140H669 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 06/10/1997 |
| From: | Matthews W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | |
| Shared Package | |
| ML20140H659 | List:
|
| References | |
| LER-97-005-01, LER-97-5-1, NUDOCS 9706180407 | |
| Download: ML20140H669 (3) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(viii) 10 CFR 50.73(a)(2)(ii) 10 CFR 50.73(a)(2)(x) 10 CFR 50.73(a)(2)(iii) 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications |
| 3381997005R01 - NRC Website | |
text
L NRC FORM 366 u.s. NUCLEAR REGULATORY COMMisslON APPROVED KY oMB No. 3150-0104 (4-95) l, EXPIRES 4/30/98 SUr'cEv%"EluU"cE'c'OEc'E f!"Jis'rUs*
' LICENSEE EVENT REPORT (LER)
"4 "Es?",c'*%*c%"Te ^"A L "?o"^&O
' "*"?L"a"a W2no"L*""?:M'",*" '*
3 (see reverse for required number of digits / characters for each block)
'w,Mys8 oc % ta REG A y0 P
l
%2i"3",5%:*M&"" *' "'*""
l f ACILfIY NAME (1)
DOCKET NUMBER (2)
PAGE (3) t North Anna Power Station. Unit 1 05000338 1OF3 l
l TITLE (4) l MISSED SURVEILLANCE ON FIRST INSERVICE INSPECTION OF STEAM GENERATOR TUBES l
l EVENT DATE (5) l LER NUMBER (6)
REPORT DATE (7)
OTHER FACILITIES INVOLVED (8) l l YEAR l SEQUENTIAL REVISION uGNTN day vEAR MONTH day YEAR l
l NUMBER NUMBER 05000 FACW NAME 05 19 97 97 005 00 06 10 97 DOWMENT NUMBER 05000 l
OPERATING l THIS REPORT IS SUBMITTED PURSUANT To THE REQUIREMENTS oF 10 CFR 6: (Check one or more) (11)
MODE (9) 6 l
20.2201(b) 20.2203(aX2Xv) x 50.73(aX2)(i) 50.73(a)(2)(viii)
POWER l
20.2203(a)(1) 20.2203(aX3XI) 50.73(a)(2)(ii) 50.73(a)(2)(x)
LEVEL (10) 0 20.2203(aX2Xi) 20.2203(aX3Xii) 50.73(a)(2)(iii) 73.71 20.2203(a)(2)(ii) 20.2203(a)(4) 50.73(a)(2Xiv)
OTHER 20.2203(aX2)(iii) 50.36(cX1) 50.73(a)(2Xv)
Speofy M Abstract below l
20.2203(a)(2)(iv) 50.36(cX2) 50.73(a)(2 Xvii) or in NRC Form 366A
'~
~~
~
LICEbE CONTACT FoR THIS LER (12)
INAME TELEPHONE NUMBER (includie Area Code)
W. R. Matthews, Station Manager (540) 894-2101 l
COMPLETE oNE LINE FoR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13) l
CAUSE
SYSTEM COMPONENT MANUFACTURER REPORTABLE ~
CAUSE
SYSTEM COMPONENT MANUFACTURER REPORTABLE l
TO NPRDS TO NPRDS-l m -.am I
t l
SUPPLEMENTAL REPORT EXPECTED (14)
EXPECTED MONTH DAY YEAR I
YES No submission (If yes, complete EXPECTED SUBMISSION DATE)
ABSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typewntten knes) (16) l On May 19,1997, with Unit 1 in Mode 6, Refueling, it was determined that the eddy-current testing results performed during the current refueling outage did not match signatures reported during l
preservice baseline testing. This discrepancy became apparent when a review of preservice inspection data was performed during the inspection of "A" steam generator (SG). Additional reviews identified two tubes in "A" SG that were not preservice inspected. Technical Specification 3.4.5 allows a reduced inspection scope if each tube in each SG is preservice inspected. Since the failure to perform a preservice inspection of these two tubes was not previously identified, only two SG's instead of three were inspected during the first refueling outage, as required by TS Table 4.4-1. This event is reportable pursuant to 10CFR 50.73(a)(2)(i)(B).
l l
The cause of this event is attributed to personnel error during preservice inspections which resulted in i
the failure to perform a preservice inspection of two tubes in the "A" SG.
This event posed no significant safety implications, since the inspections that were performed during the current outage did not identify any concerns relative to tube degradation. Therefore, the health and safety of the public were not affected at any time during this event.
9706180407 970610 PDR ADOCK 05000338 S
I, l
f NRC FORM S66A u.S. NUCLEAR REGULAYoRV CoMM'SSION l,
(4-93) l LICENSEE EVENT REPORT (LER) l TEXT CONTINUATION FAclLITY NAME (1)
DOCKET LER NUMBER (6)
PAGE (3)
North Anna Power Station Unit 1 05000338 lTuYEa*lE80E 97 005 00 2 OF3 TEXT (if more space is required. use additional copies of NRC Form 366A) (17) 1.0 Descriotion of the Event i
On May 19,1997, it was discovered that a preservice inspection was not conducted on two Unit 1 Steam Generator tubes [ Ells SG TBG). All steam generators are required to be inspected during the first inservice Inspection if a preservice inspection was not conducted on each tube in each generator. Since the preservice inspection failed to include these two tubes, verbatim compliance with the subsequent inspection requirements was not achieved.
This determination was based on the fact that First insentice eddy current inspection, performed in 1994, was limited to two (2) rather than three (3) Unit 1 Steam Generators, as l
required by TS Requirement 4.4.5.1 and Table 4.4-1.
This discrepancy became apparent when eddy-current testing of Unit 1 Steam Generator tube l
R21-C23 during the current refueling outage, indicated a manufacturing buff mark (MBM) l signal that was different from its baseline data. Further verification of adjacent tubes then l
found an identical MBM signal in a different position which led to the conclusion that the l
baseline inspection of tubes was misreported by the manufacturer and that actual data had not been provided. This re-inspection also revealed that tube R22-C23, which had been included in the population of steam generator tubes inspected during the previous 1994 refueling l
outage, was also missed and incorrectly documented during its baseline inspection. A review of base-line tapes,1994 data, duplicate testing and verification of current signatures, has l
failed to identify further discrepancies. Therefore, adequate assurance has been provided to confirm that the proper tubes have now been tested and mapped.
2.0 Sianificant Safety Consecuences and lmolications This event posed no significant safety implications since no degradation was identified during the 1994, First In-service and 1997, Second Inservice outage inspections of Unit 1 "A" Steam l
Generator tubes. To date,100% of the tubes in Unit 1 "A" and 50% of the tubes in "B" and "C" l
Steam Generators have been reinspected since the preservice inspection, with no tube discrepancies noted. This significantly exceeds (67% actual ) the 9% required by TS's, even if all three SG's had been examined during the first refueling outage. Additionally, based on l
analysis guidelines, over 800 " indications" requiring signal comparisons (primarily MBM l
indications) to baseline data have also been examined to-date. The re-inspection of Unit 1 "A" Steam Generator tubes included the sampling of 35 tubes in the area adjacent to the 2 tubes in question. No further discrepancies were noted, other than the two reported above.
l This data thus provide sufficient confidence that this anomaly was an isolated event.
Therefore, the health and safety of the public were not affected at any time during this event.
This event is reportable pursuant to 10 CFR 50.73 (a)(2)(i)(B), as a condition prohibited by Technical Specifications (TS) 4.4.5.4 (a)(9).
i NRC FORM 866A U.S. NUCLEAR REGULATORY COMMISSION (4-95) j LICENSEE EVENT REPORT (LER)
TEXT CONTINUATION FACILITY NAME (1)
DOCKET LER NUMBER (6)
PAGE (3)
North Anna Power Station Unit 1 05000338
- R lSE l "NU U
97 005 00 3 OF3 TEXT (if more space is required, use additional copies of NRC Form 366A) (17)
3.0 Cause of the Event
l The cause of this event is attributed to personnel error on the part of the Steam Generator Manufacturer during preservice inspection reporting.
l
4.0 Immediate Corrective Actions
l l
Immediate corrective actions included: a) dupiicate eddy-current testing to verify current signatures, b) additional verification to assure that tube R21-C23 and R22-C23 were tested l
and properly mapped, c) a base line search to determine if tubes in question were miscoded l
during base line activities, d) an initial determination that tubes R21-C23 and R22-C23 in Unit 1 "A" Steam Generator were not tested during initial base line.
5.0 Additional Corrective Actions
Virginia Power performed a Condition Monitoring Evaluation and Operational Assessment based on Steam Generator Inspections performed during the North Anna Unit 1, May 1997 l
Refueling Outage.
j 6.0 Actions to Prevent Recurrence Since preservice baseline inspections will not be conducted again on these steam generators, no specific actions related to preservice inspection are needed. However, improvements in acquisition software and analysis guidelines, made since the initial baseline inspection, have provided additional assurance that should preclude misidentification of tubes during future inservice inspections.
)
7.0 Similar Events
None.
8.0 AdditionalInformatiRD During this time, Unit 2 was operating at 100% power and was not affected by this event.
A review of Unit 2 History showed no similar concern regarding missed eddy current testing of SG tubing during Preservice Inspections. History indicated that "B" and "C" Steam Generators were each inspected at the 50% level after the initial cycle of operation, with no discrepancies identified.
l 1