ML20086L039
| ML20086L039 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom  |
| Issue date: | 02/06/1974 |
| From: | Boyer V PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC |
| To: | Knuth D US ATOMIC ENERGY COMMISSION (AEC) |
| Shared Package | |
| ML20086L017 | List: |
| References | |
| NUDOCS 8402070137 | |
| Download: ML20086L039 (6) | |
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PHILADELPHIA ELECTRIC COMPANY 23O1 MARKET STREET
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PHILADELPHIA. PA.19101 t2 5 4i"4500 em Ibbruary 6, 1974 vic. m..o""
Dr. D. F. Knuth, Director Directorate of Regulatory Operations l
United States Atomic Energy Commission
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Washington, D.C.
20$h$
SUBJECT:
Significant Deficiency Interim Report Main Steam Line Piping-External Surface Indications Peach Bottom Atomic Power Station, Unit No. 3 AEC Construction Permit No. CPPR-33
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i File: QUAL 2-10-2 SDR No. 7
Dear Dr. Knuth:
In compliance with 10 CFR $0.55 paragraph (e), we are hereby submitting the attached Significant Deficiency Interim Report of
.c the subject piping surface indications.
'Dio Philadelphia Electric Company reported this item to the USAEC, DRO I organization by telecon on January 7,197h.
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Sincerely,
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Attachment GRH/RAN:lew I
Copy to J.P. O'Reilly, USAEC l
8402070137 740603 PDR ADOCK 05000278 S
PDR s
Significan' ficiency Int 3 rim Report - SDR 7
Uni -
3 Main Stest Line Piping
/
External Surfaco Iadications Peach Bottom Atonic Pcuar Station-Unit 3 AE Construction Pernit No. CPPR - 38 Loscription of Deficiency It was reported to Philadelphia Electric Company the latter part of Decembor,1973, that some external surface indications had been visually identified on Unit 3 main stean piping within the primary containment between the roactor vescol and the inner main steam isolation valves. The surface indications ware identified by personnel of the exanination agency contracted by Philadelphia Electric Company to perform the pre-operational baselino examination of the Units 2 and 3 reactor vessel, piping and equip-c ment por ASME Section XI requirements.
Prior to the performance of the actual exanination of piping and equipment welds and heat affected zones, the examination agency personnel walk down piping systems ta visually examine sur' ace conditions.
It was during this walk down that the reported in-dications were observed.
Tho surface indications are:
a.
One indication on the outside radius of the 1200 bend in the "D" main stean lino downcomer from the reactor pressum vessel.
Based on visual examination, this indication appears to be an open lap in the piping plate approxinately 1/8" wide and approximately 1" long.
b.,
8 to 10 parallel circumferential indications of varying depths and lengths on the outside bend radius of the "B" main steam line safety valve ring header. Theco indications were located at one end of the ring header adjacent to the head end cap circunfomntial wold and were distributed in two areas approx-imately one inch square each.
Based on visual examination, one indication app 3ars to be approximately.080" deep by approx-imately 1" long and appears to be the worst case. The pip.
wall thickness in the areas of these indicatiens is sufficiently oversized (ncMinally 1.0$0") so that the design minimum wall thickness (0.950") appears not to have been reached by the sur-face discontinuities.
The above indications were reported to AEC DRO I by telecon on January 7, 197h. Since that date, a partial examination of the other Unit 3 main steam headora has revealed similar circunferential indications of varying langth and depth on the
'.'A" main steam line ring header at the outbond radius.
The main steam piping is carbon stool (ASTM A-155 made from ASTM A-516, Grado KC? 70 plate) and was supplied by the NSSS vendor. The ring headers and bends in the downcomers are formed by an incremental bending process during manufactum.
Both the piping fabricator and the NSSS vendor conclude that the indications which have been noted are the result of " hot tears" in the high strain areas of the pipe which were induced during the bonding process.
Surface indications of this natura if they occur are nonnally idantified in the manufactumr's shop and repaired prior to shipment to the plant site.
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Corrective Action 1.
There are a total of four nain stean headers with downconers on Unit No. 3.
A progran for exanination of the high strain areas of in-cremontal bended pipe is being implemented at the plant site and re-pair procedures are being developed to remove the indications.
2.
The manufacturer's rvcord package for the nain stean piping and other incremental bent piping will be reviewad in an attempt to determine why these indications were not identified in the shop.
3 Unit 2 has received a walkdown and baseline exanination by the same Section XI exanination agency personnel who identified the Imported intilcations on Unit 3.
There were no indications of the nature do-scribed above found on Unit 2.
The manufacturer's records will also be reviewed to determine if further investigation is necessary.
Safety Imnlicationu Potential safety implications resulting from the surface indications are being reviewed.
Conpleted Significant Deficiency Report It is anticipated that the final report will be completod on or about April 15,197h.
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PHILADELPHIA ELECTRIC COMPANY 2301 MARKET STREET PHILADELPHIA, PA.19101 (215)841-4500 February 6, 1974 Dr. D. F. Knuth, Director Directorate of Regulatory Operations United States Atomic Energy Cossaission Washington, D.C.
20$h5
SUBJECT:
Significant Deficiency Interim Report Main Steam Line Piping-External Surface Indications Peach Botton Atomic Power Station, Unit No. 3
/
AEC Construction Pennit No. CPPR-38 File: QUAL 2-10-2 SDR No. 7
Dear Dr. Knuth:
In compliance with 10 CFR 50.55 paragraph (o), we are hereby submitting the attached Significant Deficiency Interim Report of the subject piping surface indications.
'Ihe Philadelphia Electric Company reported this item to the USAEC, DRO I organization by telecon on January 7,197h.
Sincerely, u
A' T'h i
U Attachment GRH/RAN law Copy to J.P. O'Reilly, USAEC G
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_3 1416 L
o Significant Doriciency Intsrim Report o
. 7 dDR No Unit No. 3 Main Steam Lino Piping External Surface Indications Peach Bottom Atomic Power Station-Unit 3 AEC Construction Permit No. CPPR - 38 Description of Deficiency It was reported to Philadalphia Electric Company the latter part of December,1973, that some extemal surface indications had been visually identified on Unit 3 main stoan piping within the primary containment between the reactor vessel and the inner main stean isolation valves. The surf ace indications were identified by personnel of the examination agency contracted by Philadelphia Electric Company to perform the pro-operational baselino examination of the Units 2 and 3 reactor vossol, piping and equip-mont por ASME Soction II requirements.
Prior to the performance of the actual examination of piping and equipment welds and hont affected sonos, the examination agency personnel walk down piping systems to visually examine surface conditions.
It was during this walk down that the reported in-dications were obsurved.
Tho surfaco indications are:
a.
One indication on the outside radius of the 1200 bond in the "D" main steam lino downcomer f con the reactor pressum vessel.
Based on visual examination, this indication appears to be an opon lap in the piping plate approximately 1/8" wide and approximately 1" long.
b.
8 to 10 parallol circunferential indications of varying depths and longths on the outsido bend radius of the "B" main steam lino safety valvo ring header. Those indications were located at one end of the ring header adjacent to the head end cap circumferential wold and were distributed in two areas approx-imately one inch square each.
Based on visual examination, one indication appears to be approxime.toly.080" doop by approx-imately 1" long and appears to be the worst case. The pipe wall thickness in the areas of those indications is rufficiently oversized (nominally 1.050") so that the design minimum wall thickness (0.950") appears not to have boon reached by the sur-face discontinuities.
The above indications wore reported to AEC DRO I by telecon on January 7, 197h. Since that date, a partial examination of the other Unit 3 main steam headora has revealed similar circunferential indications of varying length and depth on the "A" main steam line ring header at the outbond radius.
The nain steam piping is carbon stool (ASTM A-155 mado fron ASTM A-516, Grado KCF 70 plato) and was supplied by the NSSS vendor. The ring headers and bonds in the downcomers are formed by an incremental bending process during manufacturu.
Both the piping fabricator and the NSSS vendor conclude that the indications which have been noted are the result of " hot tears" in the high strain areas of the pipe which were induced during the bending process.
Surface indications of this nature if they occur are nonna117 identified in the manufacturur's shop and repaired prior to shipment to the plant site.
O O
Correctivo Action 1.
There are a total of four main steam headers with downcomers on Unit No. 3.
A program for exanination of the high strain areas of in-cromontal bonded pipe is being implemented at the plant site and re-pair procedures are being developed to mmove the indications.
2.
The manufacturer's record package for the main steam piping and other incrumental bont piping will be reviewod in an attempt to detemine why thoso indications wore not identified in the shop.
3 Unit 2 has received a walkdown and baseline examination by the same Soction XI examination agency personnel who identified the mported indications on Unit 3.
There were no indications of the nature de -
scribed above found on Unit 2.
The manufacturer's records will also be reviewod to dotormino if further investigation is necessary.
Safety Implications Potential safety implications resulting from the surface indications are being reviewed.
Congleted Significaat Deficiency Report It is anticipated that the final. report will be completed on or about April 19,197h.
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