ML19256F240
| ML19256F240 | |
| Person / Time | |
|---|---|
| Site: | Turkey Point, Surry  |
| Issue date: | 11/28/1979 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML19256F233 | List: |
| References | |
| NUDOCS 7912180354 | |
| Download: ML19256F240 (4) | |
Text
2.0 EXPERIENCES
- 2. 2 Surry Unit 2 2.2.3
. Licensee Remedial Measures and Regulatory Actions 2.2.3.1 Plant System.nodifications None 2.2.3.1 Operations Modifications None 2.2.3.3 Steam Generator Modifications Access Hole Since the steam generator tube inspections resulted in a limited amount of useful data regarding the failed tube (RIC7), VEPC0 elected to drill a three (3) inch access hole in the steam generator in order to cut the failed tube U-bend and eight others just above the seventh support plate and remove them from the Tubes Plugged The corrective action consisted of plugging approximately 400 additional tubes in all three steam generators.
This additional plugging increased the total percentage of tubes plugged in Unit No. 2 to approximately 9.6 percent.
Since this level was higher titan the 6 percent limit assumed in the latest revision of the LOCA-ECCS analysis, the analysis was revised to envelop the in:reased level of steam generator tube plugging.
Systematic implementation of the procedure described in the VEPC0 submittal datec October 19, 1976 has resulted in plugging the tubes listed below of all three steam generators in Unit No. 2 to preclude the consequences of the U-bend ovality phenomena.
Row 1 (All Tubes in Row 1)
Row 2 Columns 5 through 12 20 through 28 36 through 43 52 through 59 67 through 75 83 through 90 Row 3 Columns 7 through 10 22 thrcugh 26 38 through 41 54 through 57 69 through 73 85 through 88 jfQQ Qf}
t 7912180 3M Modifications At Other Plants as a Result of the Surry Experience A three-inch inspection port was installed in Steam Generator B at Turkey Point Unit No. 4, in steam generator A at Surry Unit No. 1, and in a steam generator at Indian Point Unit No. 2.
These ports permit visual and TV videotape records to be obtained at these plants.
At least nine tubes in Row 1 and, where practical, an equivalent number in Row 2 were removed from Turkey Point Unit No. 4 Steam Generator 3 and Surry No. 1 Steam Generator A for subsequent examination. The tubes were TIG cut just above the upper tube support plate.
This permitted removal of the entire U-bend plus several inches of straight length below the tangent point. This same technique and sample recovery was successfully utilized at Surry Unit No. 2, Steam Generator A in Row 1.
2.2.3.4 Regulatory Actions Technical Specifications The Technical Specifications had not been updated to Regulatory Guide 1.83, however, the inspection was reviewed and approved by NRC.
NRC Requests The letter dated September 22, 1976 requested information regarding the surveillance and test program from VEPC0 for the NRC review.
NRC Requirements NRC approval was required before Unit 1 and l'ait 2 were returned to power.
The Unit 2 license was amended on September 26, 1976 to add the following paragraph:
E.
Steam Generator Insocction In order to perform an inspection of the steam generators, the plant shall be brought to the cold shutdown condition within 61 equivalent days of operation from the effective date of issuance of this amendment.
For the purpose of this requirement, equivalent operation is defined as operation with a primary 1608 044 coolant temperature greater than 350*F.
Nuclear Regulatory Commission approval shall be obtained before resuming power operation following this inspection.
On January 19, 1977, the Unit 1 license was provided with a similar license condition.
Both Unit i and Unit 2 were put under orders dated February 8, 1977 and July 1, 1977 respectively.
Those orders were superceded by license amendments on December 29, 1978 and October 3, 1978 respectively.
I608 045
2.0 EXPERIENCE 2.3 Doel Unit 2 2.3.3 Licensee Remedial Measures and Regulatory Actions 2.3.3.1 Plant System Modifications None 2.3.3.2 Operations Modifications Procedure Modification The accident was successfully terminated using the presently existing procedures which, with only one exception, proved to be adequate.
The plant systems used to mitigate the consequences of the incident and bring the plant to safe shutdown condition functioned satisfactorily and the actions taken by the operator contributed to the safe conclusion of the incident.
No radioactive releases or equipment damage was experienced.
In the future, the procedure dealing with containment isolation will have to be revised.
The procedures have to be reviewed considering the cancel-lation of phase A isolation to restore compressed air supply in the reactor building.
2.3.3.3 Steam Generator Modifications None 2.3.3.4 Regulatory Actions None 1608 046
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