ML17318A505
| ML17318A505 | |
| Person / Time | |
|---|---|
| Site: | Cook  |
| Issue date: | 11/30/1979 |
| From: | Dolan J INDIANA MICHIGAN POWER CO. (FORMERLY INDIANA & MICHIG |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| IEB-79-17, NUDOCS 7912200036 | |
| Download: ML17318A505 (5) | |
Text
INDIANA L MICHIGAN ELECTRIC COMPANY P. O.
BOX 18 BOWLN G GR E EN STATION HEW YORK, N. Y. 10004 November 30, 1979 AEP:NRC:00306 Donald C.
Cook Nuclear Plant Units 1 and 2
Dockets No. 50-315 and 50-316 Licenses No.
DPR-58 and DPR-74 IE BulIetin 79-17, Revision 1
Mr. J.
G. Keppler, Regional. Director U.S. Nuclear Regulatory Commission Office of Inspection and Enforcement 799 Roosevelt Road Glen Ellyn,Il.
60137
Dear Mr. Keppler:
This letter is in response to Revision 1 of IE Bulletin No. 79-17, which was transmitted to us by your letter dated October 30, 1979.
This letter serves also as the report required by Item 6 of the subject Bulletin.
The non-destructive examinations (NDE) required by the original version of the Bulletin were completed on the Donald C.
Cook Nuclear Plant Units 1 and 2 as of November 21, 1979.
These examinations in-cluded ultrasonic and penetrant testing.
Their scope was defined in our letter dated September 6,
1979 (AEP:NRC:00255), which responded to the original Bulletin.
Preliminary results indicate that no stress corrosion cracking was found.
Additional lines have been identified to conform with the NRC definition of stagnant borated wate1 lines as stated in Revision 1 of the subject Bulletin and are listed in Attachment l.
- However, we feel that no further examinations are required in order to fulfillthe intent of the subject Bulletin.
We base our decision on the following reasons.
a)
The additional lines are extensions of the 29 lines identified in our September 6,
1979 response.
These additional lines are flushed at least once monthly.
The previously identified lines are con-sidered to be more severe cases of stagnant borated water lines due to less frequent flushing.
Mr. J.
G. Keppler, Regi:onal Di'rector AEP;NRC;Q03Q6 h
b)
The approach used to select the sample welds in the previously identified 29 lines meets the criteria of the revised Bulletin as well as the original Bulletin in that:
1)
The sample welds do not include any low carbon content (less than
.05 wt.X) types of stainless steel; 2)
The ten percent sampling applies to each pipe size/schedule category as well as the overall population of welds and is without bias as to piping configuration; 3)
The welds selected in the emergency core cooling system outnumber those in other safety-related systems.
c)
All sample welds were examined by both ultrasonic and penetrant methods.
No exemptions from ultrasonic examinations were taken even in the case of piping having wall thickness less than
.250 inch.
d)
The Section XI visuaT examination required by Item 2(a) of the subject Bulletin.has been completed on all of those Unit 1 lines and most of those Unit 2 lines which were identified in our September 6,1979 response.
All results have been acceptable.
The remaining Unit 2 examinations will be completed as soon as practical, but after the current refueling outage so that these systems can be pressurized.
We expect the remaining visual ex-aminations on Unit 2 to also have acceptable results.
e)
The preliminary results of the NDE performed by Southwest Research Institute (SwRI) indicate that no stress corrosion cracking has been found on any of the sample welds inspected in the Donald C.
Cook Nuclear Plant Units 1 and 2.
The NDE procedures used by SwRI have a demonstrated capability of detecting such cracking in stainless steel piping.
We shall inform you if the review of the final NDE report or if the remaining Unit 2 visual inspections provide indication of stress corrosion cracking.
Very truly yours, JED:em cc:(ATTACHED) ohn E. Dolan Vice President
Nr. J.
G. Keppler, Regional Director AEP:NRC:00306 cc:
R.C. Ca'lien G. Charnoff D. V. Shaller -Bridgman R.
S.
Hunter R.
W. Jurgensen
Mr. J.
G. Keppler, Regional Di.rector AEP',NRC;00306 bc:
S. J. Milioti/J. I. Castt esana/J.
F. Etzweiler H.
N. Scherer, Jr.
R.
F. Hering/S.
H. Stetnhart/J, A, Kobyra/J, R, Jensen T.
W. Baker/D.
Vadodar ta/K. Daledda R. F. Kroeger A. Papai-Bridgman J.
F. Stietzel-Bridgman D. Wigginton -NRC Cook Plant Resident Inspector
-.NRC AEP:NRC:00255 AEP.'NRC:00306 DC-N-6015.3,1
ATTACHMENT 1 TO AEP;HRC:00306
RESPONSE
TO IE BULLETIN 79-17 REVISION 1
The additional piping runs in the Cook Nuclear Plant which come under the NRC definition of stagnant borated water lines are:,
30.
Three charging pump discharge legs to the main discharge header.
31.
Suction header to three charging pumps.
32.
Two charging pump recirculation legs to main recirculation header.
33.
From IMO 255 and 256 to Boron Injection Tank.
34.
RHR system from RWST thru heat exchanger including recirculation lines.
35.
CTS system from RWST thru pumps to IMO-210 5 211 and IMO-220 5 221.
36.
From RWST to safety injection pumps.