ML18095A823
| ML18095A823 | |
| Person / Time | |
|---|---|
| Site: | Salem  |
| Issue date: | 03/25/1991 |
| From: | Labruna S Public Service Enterprise Group |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9104020176 | |
| Download: ML18095A823 (3) | |
Text
,
e PS~G Public Service Electric and Gas Company P.O. Box 236 Hancocks Bridge, New Jersey 08038 Salem Generating Station U. s. Nuclear Regulatory Commission Document Control Desk Washington, DC 20555
Dear Sir:
SALEM GENERATING STATION LICENSE NO. DPR-70 DOCKET NO. 50-272 UNIT NO. 1 March 25, 1991 TECHNICAL SPECIFICATION SURVEILLANCE NOTIFICATION REQUIREMENT 4.4.5.5.a On March 20, 1991, Steam Generator (S/G) tube plugging was completed.
Attached is a list of the plugged tube locations completed this outage.
In all, thirty-two (32) tubes were plugged of which:*
fourteen (14) tubes were due to imperfection depths greater than or equal to 40%;
six (6) tubes were due to imperfection depths between 36 and 39%;
three (3) tubes with single axial indications; one (1) tube with a 19% cold leg tubesheet indication; three (3) tubes were due to probe restrictions; one (1) tube with single circumferential indication; one tube's cold leg (it should have been plugged last outage);
one (1) tube which had not been heat treated (at its U-Bend) and two (2) "fish mouth" tube ruptures were identified and replugged.
The two tubes with fish mouth ruptures were found in No. 14 Steam Generator (S/G).
They are located at Row 1 Columns 2 and 3 on the
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SIG Row/Column 11 18/59 31/79 12 2/63 3/58 20/89 24/52 27/69 29/25 38/46 38/69 40/24 41/42 41/60 41/63 43/48 Steam Generator Tubes Plugged 9th Refueling Outage
% Depth SIG Row/Column 67 13 7/3 34 ****
11/48 12/3 14/48 33/78 14 1/2 82 1/3 93 6/67 95 14/67 41 18/11 80 37 18/12 37 25/85 39 26/82 41*
26/86 46 28/44 42 38/39 36 39/40 ATTACHMENT
% Depth Single Axial Indi.
48 Single Axial Indi.
41 Restricted Access For Examination Tube Rupture ***
Tube Rupture ***
Single Axial Indic.
Single Circ. Incic.
Restricted Access For Examination Cold Leg Plugged
- 52 56 19 *****
36 37 45 NOTES:
- Cold leg was mistakenly not plugged during last outage Tube was plugged because no U-Bend heat treatment was performed Fish mouth tube rupture; existing explosive plugs (installed circa 1977) were drilled and the tube replugged This indication (34%) was identified by a 650 Eddy Current Probe 19% indicated at the cold leg tubesheet
.*i' TO:
NRC 3/25/91 hot leg side where the tube lane blocking device had been installed.
They were subsequently replugged.
These tubes had been previously plugged (circa 1977) with explosive type plugs.
Apparently, the plugs had leaked resulting in overpressurization of the S/G tubes and the subsequent rupture.
Total leakage due to both tube ruptures has been calculated to be less than 2 gallons/day (Technical Specification 3.4.6.2 limit is 500 gallons/day).
An evaluation was performed by Westinghouse which concluded that the remaining explosive plugs do not represent an "unreviewed safety question".
Additional fish mouth leakage, from other explosive plugged tubes, is not expected.
The integrity of the tubesheet, tube support plates, and the explosive plugs are expected to be maintained during all plant conditions.
This notifi.cation is being made, within fifteen (15) days after tube plugging, as required by Technical Specification Surveillance 4.4.5.5.a.
MJP:pc Sincerely yours,
- s. LaBruna, General Manager -
Salem Operations I