ML20086C019
| ML20086C019 | |
| Person / Time | |
|---|---|
| Site: | Waterford  |
| Issue date: | 05/31/1995 |
| From: | ENTERGY OPERATIONS, INC. |
| To: | |
| Shared Package | |
| ML20086C018 | List: |
| References | |
| PROC-950531, NUDOCS 9507060237 | |
| Download: ML20086C019 (6) | |
Text
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O ENTERGY OPERATIONS,INC.
WATERFORD STEAM ELECTRIC STATION UNIT NO. 3 BASEMAT MONITORING PROGRAM REPORT NO. 6 1
May 1995 1
Prepared By:
M. R. Gutierrez Reviewed By:
J. P. Burke 9507060237 950630 PDR ADDCK 05000382 P
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ENTERGY OPERATIONS, INC.
WATERFORD STEAM ELECTRIC STATION UNIT NO. 3 BASEMAT MONITORING PROGRAM f
REPORT NO. 6 TABLE OF CONTENTS Section 1111.g Eggg 1.0 PURPOSE 1
2.0 SCOPE 1
3.0 CONCLUSION
2 4.0 RESULTS AND DISCUSSIONS 2
5.0 CHANGES 3
6.0 REFERENCES
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4 1.0 PURPOSE i
The Nuclear Plant Island Structure (NPIS) Common Foundation Basemat 4
Monitoring Program required by Waterford 3 Technical Specification Section 6.8.4.e has been established to provide continuing assurance of basemat integrity and to ensure that conditions within the basemat do not change significantly. The monitoring program is being implemented according to Entergy Operations, Inc. Procedures N0ECP 402, NPIS Common Foundation Basemat Integrity Check, and CE-002-100, Chemistry Technical Specification Surveillance Performance Coordination. This is the sixth Basemat Monitoring Program Report prepared for the U.S. Nuclear Regulatory Commission.
2.0 SCOPE This report documents the results of the NPIS Common Foundation Basemat j
Monitoring Program for the period of June 1993 to May 1995.
During this period, two basemat survey and crack width surveillances were performed l
in July 1993 and September 1994 and eight groundwater chloride content and elevation measurements were taken.
Requirements j
Technical Specification Section 6.8.4.e states that the program will monitor the settlement of the basemat, changes in ground water chemistry that could effect corrosion of reinforcing steel, changes in crack width, and seasonal variation in ground water levels.
Acceptance Criteria The measurements taken to comply with the technical specifications are compared with the acceptance criteria and requirements stated in Reference 5.
The acceptance criteria include the following:
a.
an action limit of one inch for the difference between the baseline differential settlement based on July 84 readings and the calculated differential settlement for a surveillance; b.
an action limit of 250 ppm for the measurement of chloride content in the groundwater; and c.
an action limit of 15 mils (0.015 inch) for the difference between the baseline and measured crack widths.
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2.0 ~ SCOPE (CONTINUED) j i
i No acceptance criteria is associated with seasonal variation in groundwater levels.
It is tracked to determine if there is a I
correlation with this level and the basemat sett!cment and movement.
3.0 CONCLUSION
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e All of the acceptance criteria stated in Section 2 have been met for l
this reporting period. The reported data for all the surveillances a
since the beginning of the basemat program have consistently been well i
below the action limits.
t 4.0 RESULTS AND DISCUSSIONS The data obtained for the.basemat elevations, crack width measurements, l
chloride content in groundwater, and groundwater elevations can be found in the Work Authorizations listed in Section 6.0, References.
Differential Settlement j
i Differential settlement is defined as the settlement between a monitoring point at the basemat center near the shield building and a monitoring point at the boundary of the NPIS.
The differential settlements for all eight sets of points were well I
below the action limit of one inch. The highest calculated differential settlement for this reporting period was 0.348 inches. The maximum value computed in the previous report (May,1993) was 0.372 inches.
Waterford 3 has also tracked the settlement of 27 additional points on the basemat. Reference I list the elevations.
No action limit is l
associated with these measurements. They are tracked to monitor the t
overall flexural behavior of the foundation mat. No unusual behavior l
was observed this period.
Chloride Content t
the chloride content in the groundwater remains far below the action limit of 250 ppe. The highest level for this reporting period was 17.6 ppm, measured in the east well in July,1993.
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4.0 RESULTS AND DISCUSSIONS (CONTINUED)
Crack Width Measurements The crack width measurements for the 15 cracks compared to the baseline crack widths are well below the action limit of 15 mils.
The largest crack width differential for this period was 7.4 mils at Monitoring station #15 in July 1993. The maximum value computed in the previous report (May, 1993) was 4.3 mils at station #15. Although, this value computed represents an increase from the last report, the results from the most recent survey (August, 1994), computed a crack width differential of 2.1 mils for Monitoring Station #15.
Groundwater Elevation The measurements taken of the groundwater elevation in the east and west wells have been similar. The maximum they varied was 1.2 feet in July, 1993. The groundwater elevations in the wells fluctuated during quarterly readings less than 1.5 feet.
t 5.0 CHANGES Waterford 3's master benchmark which was located on the northwest concrete footing of the abandoned transmission tower, east of the 500 kv transmission tower east of Waterford 3, was destroyed on January 6, 1994.
Prior to its demolition, a new master benchmark was established using the old master benchmark's elevation, El. +15.875 feet.
The new master benchmark is located on the northwest concrete foundation of the 500 kv tower east of Waterford 3..The mark designation of this benchmark is U 300.
It is identified on a brass disk set into the concrete foundation. This benchmark's elevation was surveyed at El.
+13.016 feet.
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O 6.0 ' REFERENCES 1.
Work Authorizations #01111219 and #01127962, Survey of Basemat.
2.
Work Authorizations #01111220 and #01127961, Survey of SBM-A and SBM-B.
3.
Work Authorizations #01111221 and #01127963, Crack Width Measurements.
4.
Work Authorizations #01111575, #01114207, #01118244, #01122410,
- 01126556, #001127864, #01130354, and #01133719, Verify Chlorides and Ground Water Elevation.
5.
Letter W3P87-Il23, K. W. Cook to NRC, Basemat Surveillance Program, dated June 26, 1987.
6.
Entergy Operations Procedure, "NPIS Common Foundation Basemat Integrity Check'," NOECP 402, Revision 0.
7.
Entergy Operations Procedure, " Chemistry Technical Specifications Surveillance Performance Coordination," CE-002-100, Revision 7.
8.
Letter W3C5-94-0101, M. R. Gutierrez to File, Basemat Settlement Master Benchmark, dated January 17, 1994.
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