IR 05000315/1990015
| ML17328A436 | |
| Person / Time | |
|---|---|
| Site: | Cook  |
| Issue date: | 09/06/1990 |
| From: | Danielson D, Ward K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | |
| Shared Package | |
| ML17328A435 | List: |
| References | |
| 50-315-90-15, 50-316-90-15, NUDOCS 9009120168 | |
| Download: ML17328A436 (7) | |
Text
U.
S.
NUCLEAR REGULATORY COHHiISSION REGION I I I Reports No.
50-315/90015(DRS);
No. 50-316/90015(DRS)
Docket Nos.:
50-315; 50-316 Licensee:
Indiana Michigan Power Company 1 Riverside Plaza Columbus, OH 43216 Licenses No. DPR-58; DPR-74 Facility Name:
D.
C.
Cook Nuclear Plant - Units 1 and
Inspection At:
D.
C.
Cook Site, Bridgman, HI 49127 Inspection Conducted:
July 11 through August 29, 1990 inspector:
ar ate Approved By:
D.
.
anse son, se Haterials and Processes Section
~/dj>o Ins ection Summary Ins ection on July ll, 16-18 24-25,
Au ust
8
and
1990 e orts o.
-1 1 D; o.
Areas Ins ected:
Routine unannounced sa ety snspectson of inservice inspection I
actsvst>es including review of program (73051)
procedures (73052),
observation of work activities (73753),
data review t73755),
an open item (92701),
and on incore thimble tube thinning (73051, 73052, 73753, and 73755).
Results:
No violations or deviations were identified.
Based on the results of ttte inspection, the NRC inspector noted the following:
The licensee adequately demonstrated the ability to properly implement the ISI program including the eddy current examinations of the steam generator tubes.
The licensee's staffing of the ISI group was adequate, and the personnel were very knowledgeable and conscientious.
One previous inspection finding was closed.
The licensee's action in resolving an open item was reviewed and found to be acceptable.
9009120i68 900906 PDR ADOCN, 05000315 G
PNU
DETAILS 1.
American Electric Power Service Cor oration (AEP)
Indiana Hichi an Power Com an I
M
- J. Droste, Engineering Superintendent
- C. Freer, Inservice Inspection Supervisor
- J. Fitchuk, Inservice Inspection Coordinator U. S. Nuclear Re ulatory Commission (NRC)
- J. Isom, Senior Resident Inspector B. Jorgensen, Senior Resident Inspector D. Passehl, Resident Inspector Southwest Research Institute (SWRI)
F. Anderson, Inspection Engineer Factor Mutual En ineerin (FME)
H. Huterspaugh, ANII The NRC inspector also contacted and interviewed other licensee and contractor employees.
- Denotes those present at the exit interview on August 29, 1990.
2.
Licensee Action on a Previous Ins ection Findin (Closed)
0 en Item (50-315/87023-02; 50-316/87023-02:
Review of NDE ro ram or e
s A through-wall crack on the 14" diameter component cooling water (CCW)
return line for the Unit 2 RHR heat exchanger initiated an inspection of the system which disclosed 14 through-wall cracks and six subsurface cracks.
The CCW system piping is from ASTH A106, Grade B and is considered safety-related.
The causes of the failure were investigated by both Gelles Laboratories, Inc., and Westinghouse Electric Company, Inc.
Based on the results of these investigations, the licensee repaired most of the defects but left some partial through-wall cracks to facilitate monitoring future growth.
The licensee was to develop an inspection program.
The NRC inspector reviewed the inspection data to date which indicated that no cracks had propagated, and the inspection program.
Further monitoring of the CCW system will be via pressure tests performed in accordance with ASME Section XI.
Documentation of examinations performed on the CCW piping system existed in the following job order packages:
Unit
Unit 2 Job Order f715736 Job Order 8015566 Job Order d703786
The NRC inspector found the action taken by the licensee to be acceptable and considers this item closed.
3.
Incore Thimble Tube Thinnin 0>> June 18, 1990, a leak detection alarm was received in the Unit 2 control room while a monthly incore flux surveillance was in progress.
Just prior to the alarm, heavy resistance was encountered while trying to insert a flux thimble into core location C-7.
Shortly thereafter, a team of operators and radiation protection personnel entered containment and successfully identified and isolated the leak by closing the'associated isolation valve.
On July 18, 1990, personnel of Cramer E Lindell Engineers, Inc., performed eddy current exao>inations (ET) on 58 Unit 2 incore flux monitoring system thimble tubes.
These tubes were newly installed in late 1988, with a thicker wall than the old tubes (old tubes 0.300" O.D.
new tubes 0.313" O.D.) and the same material, (316 stainless steel).
These tubes had experienced only one operating cycle.
The NRC inspector reviewed the ET results in detail and observed a
demonstration of the equipment calibration using the calibration standard.
Of the 58 tubes ET'd, the following are the results:
a.
Twenty four tubes had wear, distorted and damaged signals with less than 40i'~ through-wall in the area of the lower core plate, diffuser plate, and the secondary core support.
The licensee will monitor the condition of these tubes during a future inspection.
b.
The following 29 tubes had'ear signals primarily in the lower core plate region.
The tubes were replaced during this outage in items (1)
through,(4)
below.
The tubes in item (5) were repositioned to minimize wear during operation.
(1)
One tube leaked, 100% through-wall (the tube appeared to have worn through as shown by ET and by viewing the video tape inspection of tube C-7).
(2)
Two tubes had approximately 90% through-wall.
(3)
Six tubes had approximately 60% through-wall.
(4)
One tube had approximately 50% through-wall.
(5)
Nineteen tubes had approximately 40% through-wall.
c.
Five tubes out of 58 recorded no damage, no abnormal conditions, and no distorted signals.
Tubes with wall losses of 30% and greater all produced ET signals with high amplitudes, indicating a large volumetric'oss such as found in the basic vibrational wear process.
The licensee and Westinghouse are investigating as to why such a large number of tubes were found to have
wear indications, having operated only one cycle.
The licensee kept NRR informed of the above results including a presentation at NRR Headquarters on August 29, 1990.
NRR agreed with the licensee's activities and a
report will be submitted to NRR and the NRC inspector when the results of the investigation is completed.
The licensee does not believe that a similar problem exists on Unit 1, because the fuel design is different, the unit operates at reduced power, and there has been no leak, etc.
If a tube did leak during power operation, the tube may be isolated using the available isolation valve, as was done for tube C-7 during Cycle 7.
During the Fall 1990 outage, the licensee will have the thimble tubes ET'd in Unit 1.
The thimble tubes in Unit 2 will also be ET'd during the next refueling outage of Unit 2.
4.
Inservice Ins ection (ISI) Unit 2 a.
Review of Pro rara (73051)
Westinghouse Electric Corporation (W), Southwest Research Institute (SWRI), and Indiana Michigan Power Company (I&M)'ers'onnel performed the ISI in accordance with ASME Section XI, 1983 Edition, Summer 1983 Addenda.
The staff size was sufficient to ensure that the ISI work was adequately performed.
The licensee did not submit a request for a relief from the ASME Code this outage.
The NRC inspector reviewed IEM QA Surveillance Report No. QAO-90-06 of the ISI activities by SWRI and other audits/surveillances of ISI activities conducted by qualified personnel to verify compliance with the ISI program.
The ISI program was found to be incompliance with licensee commitments.
a.
Review of Procedures (73052)
All applicable ISI procedures were approved by the Authorized Nuclear Inservice Inspector (ANII) and were reviewed by the NRC inspector.
The ultrasonic examination (UT) manual pulse echo detection instruments and transducers of.various angles, sizes, and frequencies were used.
The ISI procedures were found to be in accordance with ASME Section V,
1983 Edition, Summer 1983 Addenda.
b.
Data Review and Evaluation (73755)
(1)
General The examination data was within the criteria as outlined in the applicable NDE procedures and ASME Code requirements.
The NRC inspector's review included examination of documents relative to NDE equipment, data, and evaluations.
(2)
Eddy Current Examinations (ET)
This is the first ET on the new two Westinghouse Series 51F steam generators (SGs) after operating one cycle.
The following
are the number of tubes examined (6X) in accordance with Technical Specifications, Sections 4.4.5. 1 - 4.4.5.4:
SG Ho.22-235 Tubes SG No.23-235 Tubes The following was the extent of ET in each SG:
Rows 1 - 46:
Selected tubes from the hot leg side completely around the u-bend to the top support (7th plate)
of the cold leg.
Rows 1 - 46:
Selected peripheral tubes, full length, hot leg tube end to and including the cold leg tube end.
The Zetec-18A equipment was used for the data collection, and the data was evaluated using the Zetec DDA-4 Digital Data Analysis System.
The results were that all the above SG tubes were found to be acceptable.
c.'bservation of Work Activities (73753)
The NRC inspector observed work activities and had discussions with personnel during the ISI activities.
These observations included th~. fo 1 lowing:
(1)
SWRI personnel performing ultrasonic examinati'ons on pipe weld b16S, line b'2-CTS-10, lower head to tubesheet weld PSTtl-23-01, a reactor coolant pump flywheel 824, and several reactor head closure studs.
(2)
SWRI personnel performing liquid penetrant examinations on pipe weld 816S, line 82-CTS-10, and several reactor head closure stud washers.
The NRC inspector reviewed the qualifications and certifications of all inspection personnel on site performing ISI to ensure conformance with SHT-TC-1A.
No violations or deviations were identified.
4.
Exit Interview (30703)
The HRC inspector met with licensee representatives (denoted in Paragraph 1) at the conclusion of the inspection.
The NRC inspector summarized the scope and findings of the inspection noted in this report.
The NRC inspector also discussed the likely informational content of the inspection report with regard to documents or processes reviewed by the NRC inspector during the inspection.
The licensee did not identify any such documents/processes as proprietar I 0