ML19208B262
| ML19208B262 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 08/29/1979 |
| From: | Brown S VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | |
| References | |
| 711, NUDOCS 7909190430 | |
| Download: ML19208B262 (4) | |
Text
,
i, Venco W
vlRGINI A ELECTRIC AND power COMP ANY, RICMMONQ, VIRGINl A 2)261 p
7 / "] 31 Pl: C August 29, 1979 Mr. James F. O'Reilly, Director Serial No. 711 Office of Inspection & Enforcement PSE&C/CGC:mac: wang U. S. Nuclear Regulatory Comission Dockat i1o. 50-339 Region II 101 Marietta Street, Suite 3100 Atlanta, Georgia 30303
Dear Mr. O'Reilly:
On August 24, 1979, a report was made under the provisions of 10CFRGO 55(e) concerning indications found in feedwater lines by radiography required by I.E. Bulletin No. 79-13.
In accordance with the reporting requirements of 10CFR21, the following infonnation is submitted:
A.
Name and address of reporting individual:
Mr. E. A. Baum, Executive Manager Licensing and Quality Assurance Virginia Electric and Power Company P. O. Box 26666 Richmond, Virginia 23261 B.
Facility, activity, and/or component affected:
North Anna Power Station, Unit 2 Feedwater Piping C.
Name of firm constructing the facility or supplying the component, activity or service:
Stone and Webster Engineering Corporation
- v. O. Box 2325 Boston, Massachusetts 02107 1
0.
Description of defect, deficiency, or f atiure to comply:
I.E.Bulletin 79-13 requires radiographic examination of the feedwater lines on plants with operating licenses. Since Unit 2 is approaching that milestone, we initiated a program to comply with the Bulletin. We started the program in late June by radiographing the kg feedwater to steam generator nozzle welds; in mid August we resumed the program for the balance of radiography required by the Bulletin.
The RT program resulted in N&D's being written against ten welds and two spool pieces. None of these N&D's were for indications of the 7kO g))
\\ O l' 7 90919 09~f0 '
Mr. James P. O'Reilly, Director type discussed in I.E.Bulletin 79-13; however, due to the quantity of indications found when the program resumed in August, we initiated a potentially reportable item under 10CFR50.55(e) and Part 21.
During our five day evaluation period, we determined'that most of the indications found were not reportable; however, we were unable to evaluate the indications on four welds (see N&D 3825 below) sufficiently to determine reportability, so at the end of five days they became automatically reportable.
Below is a discussion of all indications for which N&D's were written:
Radiography in late June at feedwater to steam generater nozzle welds 3 welds 1 N&D 3806, line 16" WFPD-424-601-Q2, weld at steam generator "A" - Two One was a very f aint intermittent slag line rejectable indications:
approximately 2" in length; the other was a spot of porosity with a faint linear tail about 1/8" in length. Both defects were judged unacceptable in accordance with applicable piping inspection code The slag line was not visible in the original film requirements.
It should be although the film completely met code requirements.
noted that the film used at the nozzle welds in June was of higher The porosity spot was visible sensitivity than the original film.
and judged acceptable in the original film, because the f aint linear Both defects have been repaired.
tail was not visible.
Radiography of balance of welds begun in mid August (62 welds, 3_
spool pieces N&D 3818, line 16" WFPD-422-601-Q2, weld SW Three rejectacle One was noted as lack of fusion; further evaluation indications:
determined it to be due to sharp re-entry of weld metal and not lack The second was noted as root convexity. This indication of fusion.
was due to more heat or a slightly wider root opening in the area of This condition caused a slightly heavier convexity during welding.
deposit of weld metal in this area as compared to that in theThe third remainder of the weld.The term crater crack is often used in welding a crater crack.
terminology to define any sharp or linear discontinuity associated with an arc start or stop, and may not necessarily be a true crack or Closer review of the film indicated this " crater crack" to be All thr2e defects tear.
a sharp welding discontinuity, but not a crack.
have been repaired.
I N&D 3819, line 16" WFPD-424-601-Q2, weld SW One rejectable It was noted as lack of fusion; further evaluation indication:
determined it to be due to sharp re-entry of weld metal and not lack of fusion. The defect has been repaired.
\\h viI
Mr. James P. O'Reilly, Director N&D 3820, line 16" WFPD-422-601-Q2, weld SW Four rejectable Indications: Three were noted as lack of fusion; further evaluation determined them to be due to sharp re-entry of weld metal and not lack of fusion. The fourth was noted as root convexity (mdlt through). This indication was similar to the root convexity noted in N&D 3818 above. All four defects have been repaired.
N&D 3821, line 16" WFPD-422-601-Q2, weld SW One rejectable indication:
It was noted as root convexity (melt through). However, further evaluation revealed this convexity to be within code allowarce. The melt through was slight and the deposited =acal was clean. The defect has been repaired.
N&D 3824, line 16" WFPD-424-601-Q2, weld SW One rejectable indication:
It was noted as an arc strike. The indication was'very slight and was located on the inside diameter of the pipe approximately 1" away from the weld on the parent metal. Further evaluation determined that this indication was probably not an arc strike, but rather a processing mark made during extruding operations. The defect has been repaired.
N&D 3825, line 16" WFPD-424-601-Q2, FW-18, SW-27, SW-28; line 16" WFPD-422-601-Q2, weld FW-5A - Each of these welds had one rejectable indication which was noted as foreign material. The foreign material on FW-18 has been removed by high pressure air; the other three welds were hydrolasered, with success on FW-5A and SW-22. FW-18, FW-5A, and SW-28 have all been successfully radiographed with no further rejectable indications. Further evaluation to determine a resolution for SW-27 is in progress.
N&D 3826, line 16" WFPD-423-601-Q2, spool piece WFPD 207-1; line 16" WFPD-422-601-Q2, spool piece WFPD 208 Four rejectable indications all noted as arc strikes: Visual inspection revealed WFPD 207-1 had 2 indications on its outside diameter and 1 on its inside diameter; WFPD 208-1 had one indication on its outside di 7eter. The indication.: on the outside diameters have been buffed out; for the indication on the inside diameter, visual inspection by boroscope has revealed that the indication is not an arc strike, but a tool mark which is not rejectable; minimtsn wall has not been violated for any of the above.
E.
Date of determination of reportability:
August 24, 1979 F.
Similar components, activities, or services:
Nor.th Anna Unit 1 1O cit
Mr. James P. O'Reilly, Director.
G.
Corrective action which has been, is being or will be taken, the individual responsible and the length of time to comnlete the action:
As indicated in "D" above, corrective action is complete on everything except weld SW-27 on line 16" WFPD-424-601-Q2. With that one exception, we have determined that none of the radiographic indications discussed above represents a significant deficiency or a substantial safety hazard.
H.
Other information:
None Any information not available at this time will be submitted in a follow-up letter as a 30-day report.
Should you require further information, please contact this office.
r truly u s,
/ g. rown gaa J
Senior Vic President - Power ation/
cc: Director, Office of Inspection and Enforcement (3)
O
\\ 05 s
J b