ML20031C673
| ML20031C673 | |
| Person / Time | |
|---|---|
| Site: | Callaway  |
| Issue date: | 10/02/1981 |
| From: | Baxter T SHAW, PITTMAN, POTTS & TROWBRIDGE, UNION ELECTRIC CO. |
| To: | Atomic Safety and Licensing Board Panel |
| Shared Package | |
| ML20031C639 | List: |
| References | |
| NUDOCS 8110070473 | |
| Download: ML20031C673 (6) | |
Text
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i Octobsr 2, 1981 l
l l
UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION l
l BEFORE THE ATOMIC SAFETY AND LICENSING BOARD i
In the Matter of
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UNION ELECTRIC COMPANY
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Docket No. STN 50-483 OL
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(Callaway Plant, Unit 1)
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APPLICANT'S STATEMENT OF MATERIAL FACTS AS TO WHICH THERE IS NO GENUINE ISSUE TO BE HEARD ON JOINT INTERVENORS' CONTENTION NO. II.A.1 (SA-350 PIPING)
Pursuant to 10 C.
P 2.749 (a), Applicant states, in support of its Motion for Summary Disposition of Joint Intervenors ' Contention No. II. A.1 (SA-358 Piping) in this proceeding, that there is no genuine issue to be heard with respect to the following material facts:
1.
Part II. A.1 of Joint Intervenors ' Contention No. 1 alleges that a substandard piece of SA-358 piping was approved for shipment by the vendor, was acceptec on the Callaway Plant site, and was installed in the emergency core cooling system despite these deficiencies -- the pipe was substantially out-of-round, was machined below the j
minimum wall, and had rejectable weld defects on the inside of a longitudinal seam weld.
Amended and Supplemental Joint Petition to Intervene, March 6, 1981, at 11; Revised Conten-tions of Joint Intervenors, March 24, 1981, at 1.
2.
SA-358 is an ASME material specification for welded stainless steel pipe.
The pipe is made from plate 8110 v 7 0 473.-
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by forming and rolling the plate into a continuous, tubular shape.
The longitudinal seam is then welded, usually by the submerged-arc process, with the weld made from both the inside and outside surfaces.
Affidavit of Michael F. Stuch-field in Support of Applicant's Motion for Summary Disposition of Joint Intervenors' Contention No. II. A.1 (SA-358 Piping)
("Stuchfield Affidavit"), para.
4.
3.
On April 26, 1979, a pipefitter under the employ of Daniel International Corporation, the constructor for the Callaway Plant, observed the internal weld surface irregularity in the SA-358 pipe which is the subject of Joint Intervenors' Contention No. II.A.l.
The pipefitter was in the process of preliminary work on the spool piece, prior to fit-up for welding, when he observed the internal weld surface and notified a Daniel Quality Control inspector.
Affidavit of Joseph V. Laux in Support of Applicant's Motion for-Summary Disposition of Joint Intervenors' Contention No. II.A.1 (SA-358 Piping) ("Laux Affidavit"), para.
3.
4.
The Daniel inspector, who observed the irregu-larity and a pipe ovality condition /possible thin wall con-dition, requested that an ultra-sonic test be performed to determine if the oval appearance was emblematic of a thin wall condition.
The test results confirmed the suspected thin wall area and a nonconformance report ( "NCR" ) was issued by the inspector on April 27, 1979.
A QC " Hold Tag" was applied to the spool piece.
Laux Affidavit, para.
3.
to i l 5.
The actions of the Daniel pipefitter and the Daniel Quality Control inspector (described above in para-4 graphs 3 and 4) were the required, normal actions prescribed 5-in Daniel procedure AP-VII-02, "Nonconformance Control and Reporting," which is a Daniel administrative procedure re-quiring project personnel, including craft personnel, to report nonconformances or nonconforming activities and to bring them to the attention of Quality Control or Engineering personnel.
Laux Affidavit, para. 4.
6.
The piece of SA-358 pipe which is the subject of Joint Intervenors' contention was not machined below the minimum design well thickness.
While the Bechtel specifica-tion was written to require 0.874 inch thickness, the actual minimum design wall thickness was conservatively calculated to be 0.795 inch.
The actual, measured worst-case minimum wall daickness was 0.814 inch.
Stuchfield Affidavit, para.
6; Laux Affidavit, para. 6.
7.
The piece of SA-358 pipe which is the subject of Joint Intervenors' contention was not substantially out-of-round -- i.e., does not have excess ovality.
The material specification for the pipe provides for a permissible dif-ference between major and minor outside diameters of 1%.
The actual, measured maximum ovality for the pipe in question was 0.86%.
Stuchfield Affidavit, para. 5.
8.
SA-358 permits a maximum of 1/8 inch reinforce-ment (weld metal in excess of the quantity required to fill
.I
_4 a joint).
The Daniel NCR on the pipe in question stated that there was an area of weld reinforcement on the inside of the pipe with a height of 3/16 inch.
Stuchfield Affidavit, para. 8; Laux Affidavit, para. 5.
9.
Bechtel, in its review of the NCR, incorrectly concluded, based on an inepglicable paragraph of the ASME code, that a nonconformance did not exist.
It would not have been significant, however, if the excess reinforcement had not later been removed, since a reinforcement height of 3/16 inch would have no effect on the useability of the pipe.
Stuchfield Affidavit, paras. 8, 9.
10.
The Daniel NCR on the pipe in question also identified a condition described as overlap, in the same area as the excess weld reinforcement.
The overlap apparently was excess weld material which had rolled over onto the sur-face of the pipe material.
Stuchfield Affidavit, para. 10.
11.
The overlap condition had been identified by
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ARMCO, the manufacturer of the pipe, during radiography of the weld seam.
Thia condition was considered acceptable by ARMCO.
Stuchfield Affidavit, para, 11.
12.
This type of weld imperfection (overlap) is not listed in the ASME code as a rejectable condition of radiography because it does not affect the volumetric quality of the weld.
Stuchfield Affidavit, para. 10.
13.
" Burn-through" during the process of welding from the outside could tot have caused this overlap condition.
Stuchfield Affidavit, para. 12.
. ~ _ -.. - - = - _
3 14.
The welding process used to make the longitudinal weld in this pipe is called the submerged arc process.
This J
l is a machine welding process,.where general weld quality depends on a series of parameter settings, such as arc voltage, current travel speed and wire feed speed.
A slight or momentary varia-tion in any of these parameters would cause the overlap condition.
f Stuchfield Affidavit, para. 12.
15.
Even if Daniel had not reworked the weld imper-faction by grinding, the presence of the overlap and the slightly j
higher reintorcement would not have affected the strength or i
structural integrity of the weld joint.
Stuchfield Affidavit, para. 13.
16.
The overlap and excess weld reinforement were i
repaired by Daniel by simple removal of the excess material by localized grinding.
Laux Affidavit, para. 9.
l 17.
Immediately following the removal of the excess material, a visual and liquid penetrant inspection was made l
to determine proper fusion and soundness of the weld metal, and an ultrasonic test was performed to assess wall thickness.
on May 2, 1980, a liquid penetrant examination was performed j
in the presence of the NRC Resident Inspector.
Radiography f
was performed on March 20, 1981, and was evaluated by a Daniel inspector an (
.n NRC radiographic interpretor.
All of these inspections and tests confirmed that no defects were present in the repaired subject weld.
Laux Affidavit, para. 11.
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During hydrotesting of the emergency core cooling system prior to plant operation, the subject pipe will be hydrostatically tested to a pressure of 1.25 times its design pressure.
This test will confirm the structural integrity of the weld.
Stuchfield Affidavit, para. 14.
Respectfully submitted, SHAW, PITTMAN, POTTS & TROWBRIDGE L 4. &1~
Thomas A.
Baxter Richard E. Galen Counsel or Applicant 1800 M Street, N.W.
Washington, D.C.
20036 (202) 822-1000
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