ML19253B322
| ML19253B322 | |
| Person / Time | |
|---|---|
| Site: | Zion File:ZionSolutions icon.png |
| Issue date: | 09/05/1979 |
| From: | Bryan S, Mckee P, Stone J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE) |
| To: | |
| References | |
| PNO-79-395, NUDOCS 7910110605 | |
| Download: ML19253B322 (2) | |
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h PRELIMINARY NOTIFICATION September 5, 1979 PRELIMIriARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE--PN,0-79-395 This preliminary notification constitutes EARLY notice of events of POSSIBLE safety or public interest significance.
The information presented is as initially received without verification or evaluation and is basically all p at is known by IE staff on this date.
Facility:
Commonwealth Edison Company, Zion, Units 1 and 2 (DN 50-295 and DN 50-304) -Zion, Illinois
Subject:
DEGRADATION OF REFUELING WATER STORAGE TANK (RWST) TO PIPING WELDS On September 4, 1979, the li'censee informed the resident inspector of the results of an ongoing investigation pursuant to the requirements of IE Bulletin 79-17.
On August 21, 1979, while performing visual inspections per IEB No. 79-17, the licensee observed boric acid deposits (indicates leaks from pipes containing boric acid solutions) on one pipe from the bot em of the RWST for Unit 1 and on one pipe from the bottom of the RWST for Unit 2.
The lines are, for Unit 1 a 14-inch containment spray suction line and for Unit 2 an 8-inch RHR recirculation line.
On August 22, 1979, the onsite review committee determined that continued operation was justified because the leaks did not appear active and no leakage was observed in the sight glasses of the RWST weld channel leak-off lines.
The licensee decided to remove the boric acid deposits from the lines, perform visual examinations, and to contra:t a diver with an under-water video camera to examine the pipe ID's.
Between August 21-29, 1979, scaffolding was erected and the boric acid deposits removed.
The lines were observed over a period of time and both appeared to be moist.
On the evening of August 31, 1979, a diver with an underwater video camera made dives into both Unit 1 and 2 RWST's.
The ID area of both pipes was photographed and appeared to show weld degradation in the area of the RWST to pipe weld.
Sargent and Lundy (the Architect-Engineer) performed an engineering evaluation on both lines.
The conclusion was that the Unit 1 containment spray pump suction line was seismically supported by an adjacent wall and therefore, the support of the line did not-rely on the questionable weld.
The licensee plans to repair the weld during the October, 1979, scheduled refueling outage when the RWST will be drained.
For Unit 2, a mechanical seal was placed in the line and its normally closed recirculation valve was tagged out.
Thus, the seal and isolation valve provide two isolation barriers.
The mechanical seal is.
orificed to allow comunication between the RWST and the line to relieve any pressure buildup that might be caus2d by increased temperature.
This line is not required to prevent e-mitigate the consequences of an accident.
The licensee concluded that. Unit'2 can be operated safelv until the March 1980 scheduled refueling outage:at which time weld repairs will be made.
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._ PNO-79-395 Continued Based on IEB No. 79-17, the Unit 1 containment spray pump suction.line is not. classified:as a stagnant line; h1 wever, the Unit.2 RHR(recirculation line is classified as a Wgnant line. The licensee has responded to IE8 No. 79-17 and will update -this response to include the information on the Unit 2 RHR recirculation line.
The licensee position regarding this matter will be reviewed by the regulatory staff.
The Resident Inspector is reviewing licensee's actions on this matter, and a RIII Piping /NDE Specialist-Inspector will review this matter the week of. September 10, 1979, during a scheduled inspection.
The licensee did not issue a press release.
RIII does not plan to is<ue a press release.
The State of Illinois is being nocified.
This information is current as of 2:30 p.m., September 4, 1979.
Contact:
JStone, IE x28019 PMcKee, IE x28019 SBryan, IE x28019 Distribution:
Transmitted H St Chairman Hendrie Comissioner Bradford S. J. Chilk, SECY Commissioner Kennedy Commissioner Ahearne C. C. Kammerer, CA Commissioner Gilinsky ACRS 5 : . ''
(For Distribution)
Transmitted:
HNBB P. Bldg V. Stello, IE g g Region M L. V. Gossick, EDO H. R. Denton, NRR H. L. Ornstein, EDO R. C. DeYoung, NRR J. J. Fouchard, PA R. J. Mattson, NRR Landow N. M. tialler, HPA D. Vassallo, NRR J. J. Cummings, 01A R. G. Ryan, OSP D. Eisenhut, NRR H. K. Shapar, ELD SS Bldg (MAIL)
W. J. Dircks, HMSS R. Minogue, SD S. Levine, RES
- PRELIMINARY NOTIFICATION
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