ML17325A243
| ML17325A243 | |
| Person / Time | |
|---|---|
| Site: | Cook  |
| Issue date: | 08/03/1987 |
| From: | Will Smith INDIANA MICHIGAN POWER CO. (FORMERLY INDIANA & MICHIG |
| To: | Davis A NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| NUDOCS 8708110109 | |
| Download: ML17325A243 (3) | |
Text
,ACCESSION NBR FAC IL: 50-31 5 50-316 AUTH. NAME SMITHS'. G.
RECIP. NAME DAVIS'. B.
REGUL*l INFORMATION DISTR IBUTIO YSTEM (R IDS) 8708110109 DOC. DATE: 87/08/03 NOTARIZED:
NO DOCKET Donald C.
Cook Nuclear Poeer P)anti Unit li Indiana 5
05000315 Donald C.
Cook Nuclear Poeer Plant.
Unit 2i Indiana 5
05000316 AUTHOR AFFILIATION Indiana 8c Michigan Electric Co.
RECIPIENT AFFILIATION Region 3i Office of. Director
SUBJECT:
RO: on 8?0709-0721 269 steam generator tubes plugged during insp. Tubes plugged due to p o'ss ib le tube eall degradation.
Conservative evaluation criteria applied.
DISTRIBUTION CODE:
IE01D COPIES RECEIVED: LTR J ENCL 0 SIZE:
TITLE: General (50 Dkt)-Insp Rept/Notice o% Violation Response NOTES:
RECIPIENT ID CODE/NAME PD3-3 PD COPIES LTTR ENCL REC IP IENT ID CODE/NAME WIGGINGTONt D COPIES LTTR ENCL INTERNAL:
AEOD NRR MOR ISSEAUi D NRR/DREP/EPB NRR/DR IS DI R 0
RMANi J EG ILE FILE 01 DEDRO NRR/DOEA DIR NRR/DREP/RPB NRR/PMAS/ ILRB OGC/HDSi RES DEPY GI EXTERNAL:
0 TOTAL NUMBER OF COPIES REQUIRED:
LTTR 20 ENCL SQ
0 PRTORTTY ROUTING me@icon lactrio
~yare INDIANA & MICHIGANfIfCTRIC COMPANY Donald C. Cook Nuclear Plant P.O. Box 456, Bridgrnan, Michigan 49106 c
rtt.
rr August 3, 1987 Mr. A.B. Davis United States Nuclear Regulatory Commission Region III 799 Roosevelt Road Glen Ellyn, IL 60137
Dear Mr. Davis:
Pursuant to the requirements of D.C. Cook Plant Technical Specification 4.4.5.5(a), this letter is to inform you of the number of steam generator tubes plugged as a result of eddy current examination activities performed during the 1987 Unit 1
refueling outage.
Inspection of Unit 1 steam generators began on July 9,
- 1987, was completed on July 21, 1987 and included 100 percent of all previously nonplugged tubes.
The total number of tubes examined in each steam generator included 3,368 in S/G ll, 3,366 in S/G 12, 3,363 in S/G 13, and 3,368 in S/G 14.
Conservative steam generator tube plugging criteria, similar to that utilized during inspection of Unit 2 steam generator, were implemented as follows:
In the hot leg tubesheet crevice and tubesheet surface regions (up to approximately 6 inches) all clear indications or other signals representing possible tube wall degradation, regardless of voltage or phase
- angle, were plugged.
At hot leg support plate intersections clear indications meeting a threshold voltage of 1.75 volts and having indicated through wall penetrations of R
40 percent were considered pluggable.
In addition, some indications not meeting the threshold voltage were also plugged as an additional precaution based on the recommendation of the data interpreter.
Applying the conservative evaluation criteria resulted in plugging a total of 269 tubes.
The number of tubes plugged per steam generator was 69 tubes in S/G 11, 86 tubes in S/G 12, 8708ii0109 870803 PDR ADQCK 050003i5 S
~d/
pQQ 6 15P
" Mr. A.B. Davis August 3, 1987 Page 2
24 tubes in S/G 13, and 90 tubes in S/G 14.
Of the total number of tubes plugged 69 were plugged based on Technical Specification requirements (R.40 percent tube wall degradation) and included 19 tubes in S/G ll, 31 tubes in S/G 12, 3 tubes in S/G 13, and 16 tubes in S/G 14.
Respectfully, W.G. Smith, Jr.
Plant Manager
/cbm cc:
A.A. Blind INFO L.S. Gibson INFO J.E.
Rutkowski -INFO M.'P. Alexich INFO J.G. Feinstein INFO S.H. Steinhart INFO M. Marroco/D.R. Hafer/J.R.
Jensen INFO R.F. Kroeger INFO J.R.
Sampson INFO NRC Resident Inspectors INFO R.T. Rickman INFO File