ML20116F567
| ML20116F567 | |
| Person / Time | |
|---|---|
| Site: | Catawba  |
| Issue date: | 10/11/1984 |
| From: | Kruse B, Llewellyn D AFFILIATION NOT ASSIGNED |
| To: | |
| References | |
| OL-I-167, NUDOCS 8505010136 | |
| Download: ML20116F567 (4) | |
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Ic@m 5 INVESTIGATION / RESOLUTION OF CONCERNS Page 1 of 3 ASSIGNED TO:
D. H. Llewellyn CONCERN NUMBER:
2 -
REMOVAL OF ARC STRIKES Statement of Concern In NRC Inspection Report Numbers 50-413/84-31 and 50-414/84-17, the person identified as Individual B-2 expressed concern that on one occasion his foreman had removed are strikes from valve 1NI398 in the Unit I reactor building. The welder viewed this as a violation of procedure.
TYPE OF CONCERN:
FOUNDED X
UNFOUNDED Q-1A REQUIRED _ YES
_ NO Q-1A NUMBER Investigation During second shift, Individual B-2 noticed several arc strikes on a valve on which he was preparing to complete some welds left incomplete by the first shift. He asked his f'oreman to look at the valve so that the foreman would be aware that are strikes were present. The foreman filed the are strikes off of the valve and allegedly instructed the welder to do li kewi se, if the arc strikes were "not too bad."
In subsequent interviews with other welders, Individual 109 related a nearly identical incident on valve 1NI395. Individual 196 verified this incident. Both this valve and that mentioned by Individual B-2 are located under the 1-A steam generator about ten feet apart. They are identical in size and appearance.
Both of these valves were examined.
Indications of filing were found on both valves, but only on the weld region of the valve, which is the area where filing of arc strikes would normally be expected during the course of fabrication. There were also grinding indications on the valve body.. However, discussions with the manufacturer revealed that grinding is performed on the valves during manufacturing to remove surface irregularities.
The grinding marks lacked the luster of filed regions, indicating that they were done during manufacture. No evidence of filing (as opposed to grinding) was found on the
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l body of either valve.
i A subsequent interview with Individual 109, who related the incident 1
regarding valve 1NI395, revealed that he was welding on the valve at the time the filing incident occurred. Therefore, process control authorizing cleanup of the valve socket area (by filing if required) was in the. possession of the I
l welder. (The paperwork that authorizes the weld also authorizes the removal of l
arc strikes within the weld area.) This welder further stated that he could l
not recall exactly where on the valve the filing was done.
l In order to determine whether improper filing had been done on other i
valves, all valves in critical socket weld systems welded by the welders of l
Individual 109's crew were identified; a total of 24 valves were identified.
Those that were accessible were examined for indications of filing on the valve I
body. This examination revealed that of the 19 valves that were accessible, eight of the valves had ground. regions which were done by the valve 8505010136 841011 PDR ADOCK 05000413 0
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2 Investigation (continued) manufacturer.
This grinding is a normal step in the manufacturing of the valves. One' valve (INC-019) had numerous ground regions. Six of the valves had filed regions, but in all six cases the filing was confined to the socket region of the valve (i.e., the area of the weld). There were no file marks found outside the weld region. As explained below, this indicates that no violations of procedure occurred.
Resolution The decision by the foreman to remove minor arc strikes was technically correct.
The socket area of the valve is considered the weld zone and the supervisor would be responsible for any arc strikes on components welded by his crew.
Procedures governing the process control for erection of this system permit the welder to remove arc strikes in the weld zone. Whether one crew or another created the are strikes makes no difference, as the supervisor who last works on the system is responsible for insuring the system is ready for inspection. Thus, Individual B-2 and Individual 109 were correct in bringing the arc strikes to the attention of their supervisor and the supervisor was correct in removing them. (Individual B-2 or Individual 109 could also have properly removed the arc strikes.) While interaction between these welders and their supervisor may have been poor, causing the welders to misinterpret the intent of the supervisor's direction and incorrectly assume that the foreman was violating procedure by acting without process control, in actuality no procedures were violated.
Therefore, no corrective action was necessary.
To avoid such misunderstandings in the future, meetings with craft supervision will be held to reinforce the need to make communications with their subordinates clear and consistent.
Action No additional technical action is required.
Conclusion An examination of all of the accessible valves welded by Individual 109's crew during construction revealed filing on six valves. However, this filing was confined to the weld area (valve socket) and is believed to have been done during fabrication by the manufacturer. It is therefore considered authorized.
l Moreover, no procedures were violated by the foreman when he filed minor are j
strikes from the weld area of the valve. Since the foreman was responsible for the welding of that portion of the piping system, he or his subordinates had M-4A process control to perform the work. This process control permits removal i
of arc strikes in the weld zone. If the arc strikes can be removed "with a few strokes of a file" they will be surface indications only and will not have penetrated the surface of a component.
Their removal is considered the responsibility of the welder. This concern was a result of poor communication i
l between supervision and craft.
It does not represent a violation of procedure.
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Item 5 INVESTIGATION / RESOLUTION OF CONCERNS Page 3 of 3 CONCERN NUMBER:
2 Conclusion (continued)
During this investigation several other welders voiced some more general concerns in regard to the removal of arc strikes.
Individuals 5 and 186 indicated that they were each aware of an incident wherein another welder (unnamed) had removed an arc strike without proper approval and had been issued a violation for doing so.
(These arc strikes were apparently not in the weld region or the weld had already passed final inspection.)
Individual 176 related another incident several years ago in which an inspection documented an are strike which was removed without proper process control.
Individual 102 stated that several years ago employees (unnamed) had removed arc strikes but that he had not observed this more recently.
Individual 168 stated in his interviews that he had observed other welders (unnamed) remove are strikes without process control, but that these were surface arc strikes usually near the weld, which were " easily removed with several strokes of the file."
Individual 131 stated that he had in the past seen arc strikes outside of the
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weld zone that had been filed off without paperwork, but that he had not observed this recently.
He observed that welders are now taking care to prevent this problem. Individual 191 indicated that he had removed superficial arc strikes which could be removed with several strokes of a file without checking with his supervisor. As stated above, process control permits this.
Individuals 37, 194 and 9 had heard of an incident several years ago in which a QA inspector saw a deep are strike on a pipe and red tagged it.
During a subsequent shift, the arc strike was removed and the pipe rewelded, without process control. An NCI (#14,120) was issued.
These additional incidents involve eithe[ (1) the removal of superficial arc strikes in the weld zone for which no process control is required (not a violation of procedure); (2) the removal of deeper are strikes or are strikes outside of the weld zone without p-oper approval, which was detected by QA; or (3) allegations of are strike removal in the past about which no specific information is available.
As to this last category, we note that any questionable areas on a weld would be detected during the final system inspection required by QA.
Accordingly, none of these additional incidents raise safety concerns, and none would have affected the overall quality of the plant.
INVESTIGATION / RESOLUTION:
PERFORMED BY M M w b DATEdar f/$V 8.
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