IR 05000395/1990005
| ML20012C357 | |
| Person / Time | |
|---|---|
| Site: | Summer  |
| Issue date: | 02/22/1990 |
| From: | Belisle G, Lenahan J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML20012C354 | List: |
| References | |
| 50-395-90-05, 50-395-90-5, NUDOCS 9003210101 | |
| Download: ML20012C357 (6) | |
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j 101 MARitTTA STREET,N.W.
- r AT LANT A, GEORG! A 30323
\\...+/ Report No.: 50-395/90-05 Licensee: South Carolina Electric & Gas Company Columbia, SC 29218 Docket No.: 50-395 License No.: NPF-12 Facility Name: V. C. Summer Inspection Conducted: January 2, 1990 Inspector: h .j t!t/ f6 .- J. J. Lenahan p (/ Date Signed 9hM9o Approved by: O SW
- Eda G. A. Belisle, Chief D' ate Signed Test Programs Section Engineering Branch Division of Reactor Safety SUMMARY Scope:
This routine, unannounced inspection was conducted in the areas of the containment building tendon surveillance and the service water pond monitoring programs, Results: In the areas inspected, violations or deviations were not identified.
The licensce's resolution of problems identified during previous tendon surveillance inspections is rated as a strength.
The licensee's response to NRC initiatives demonstrates a clear understanding of the issues and is conservative and technically adequate.
Personnel performing the surveillances are well qualified.
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. . , . . REPORT DETAILS
1.
Persons Contacted ' Licensee Employees
- 0. Bradham, Vice-President, Nuclear Operations
-
- H. Donnelly, Senior Engineer, Nuclear Licensing
- A. Koon Manager, Nuclear Licensing
i 'ynch,QualityAssurance(QA) Specialist,(QA) Surveillance
%. doore, General Manager, Engineering ' 'U. Proper,AssociateManager,(QA)
- J. Skolds, General Manager, Nuclear Plant Operations
- J. Todd, Civil Engineer, Design Engineering R. Whorton, Civil Engineer, Design Engineering Other licensee employees contacted during this inspection included two Quality Control inspectors.
Other Organizations
D. Krause, Structural Engineer, Gilbert Associates NRC Resident inspector
- L. P. Modenos, Resident Inspector
- Attended exit interview
2.
Containment Building Tendon Surveillance (61701) The inspector examined procedures, work-activities, and quality records > relating to the containment building tendon surveillance program.
Acceptance criteria utilized by the inspector appear in Technical Specification 3/4.6.1.6. The following are the details of the inspection: . a.
Summary of Results of Previous Tendon Surveillances In a letter dated January 17, 1986, the licensee submitted a'30 day special report which documented that several tendons examined during the third periodic tendon surveillance inspection completed in-t ' December 1985 had measured prestress forces lower than their , predicted values.
The-lower-than-predicted pre-stress values were l attributed to larger-than-predicted stress relaxation of the tendon ' wires.
The licensee conducted testing of samples of the tendon wire to determine the correct stress relaxation values.
The inspector , ! reviewed Lehigh University Fritz Engineering Laboratory Report titled L
. . ,
Stress Relaxation Test of 1/4" Prestressing Wire for SCE&G, dated February 1987.
Samples of wire from tendon number 28 BA were tested at temperatures of 68*, 90', and 104' F in accordance with ASTM E-328-78, Recommended Practice for Stress-Relaxation Test for Materials and Structures.
While some of the test data was erratic, the test results indicated that stress relaxation increases with increasing test temperatures.
Based on an average containment building temperature of 90' F, the test results disclosed that the actual stress relaxation value was 12.8 percent, not the 8.5 percent which was the stress relaxation value at 68' F.
The latter value was used by the tendon vendor. INRYC0, INC (now defunct) in designing the prestressing system. As a result of this increased loss of prestress force, the licensee's Architect Engineer, Gilbert Associates, re-evaluated the containment building design and determined that the required minimum average prestress force could be reduced from 1195 kips to 1160 kips for the vertical tendons, from 1181 kips to 1000 kips for the hcop tendons, and from 1115 kips to 1063 kips for the dome tendons.
These reduced values of average prestress force were approved by the NRC Office of Nuclear Reactor Regulation (NRR) in Amendment 76 to the Technical Specifications.
The licensee determined from the results of the first three tendon surveillances that the vertical tendons required retensioning to ensure that the required minimum average prestress force level of 1160 kips for the vertical tendons would be maintained throughout the 40 year life of the plant.
The hoop and dome tendons are not predicted to require retensioning within the 40 year life of the plant, b.
Review of Tendon Surveillance Procedures The inspector examined procedure number SP-228, Surveillance of Reactor Building Post Tensioning System.
This procedure specifies requirements for inspection, testing, analysis, and data reporting for the containment building post-tensioning system in accordance with the Technical Specifications. The ins Procurement Technical Requirements (PTR) pector also examined SCE&G number SC-33, Vertical Tendon Retensioning.
This PTR specifies requirements for retensioning of the vertical tendons and includes work to be performed, the retensioning sequence, acceptance criteria, and Quality Control (QC) inspection criteria.
The tendons are to retensioned to 67 percent of their guaranteed ultimate tensile strength (GUTS).
The tendon retensioning is to be performed in conjunction with the ongoing tendon surveillance inspection, which is the fourth periodic surveillance,- conducted 10 years after the Containment Building Structural Integrity Test.
c.
Observation of Tendon Surveillance Work Activities The inspector witnessed inspection activities performed during the surveillance of vertical tendon numbers V-2 and V-63.
These activities included sampling of the tendon corrosion protection
. . , . .
materials (grease) and inspection of the anchorage assembles and buttonheads.
The inspector witnessed the stressing operations for determination of the liftoff (prestress) forces in these tendons.
The lift off value for tendon V-63 was acceptable (greater than 95 percent of the base value) while it was slightly below (6 K!PS) the 95 percent base value for tendon V-2.
Since the liftoff force was below 95% of the base value for V-2, it was necessary per the Technical Specification to determine the lift off forces in adjacent tendons V-1 and V-3.
The inspector witnessed the stressing opera-tions for detensioning the lif t off forces in tendons V-1 and V-3.
The lift off forces in these tendons were also slightly below the 95 percent base value.
The licensee retensioned tendon V-2 and V-63 to 67 percent of GUTS per procedure PTR SC-33.
Tendon V-1 and V-3 will be retensioned at a subsequent date following completion of tendon surveillance activities in accordance with the sequence specified in PTR SC-33.
d.
Review of Quality Records The inspector examined the stressing ram calibration records for the stressing rams utilized in the tendon lift off measurements.
The inspector also reviewed calibration records for the pressure gauges used to measure the hydraulic pressure during the lift off measure-ments and the conversion of ram hydraulic pressure to tendon prestress (lift off) for tendons V-1, V-2, V-3, and V-63.
Within the areas inspected, no violations or deviations were identified.
3.
Monitoring of Service Water Pond and Service Water Intake Structure (61701) ' Operating License Conditions 2.C.(5).a through 2.C.(5).e specify require-ments for monitoring the stability of the service water pond and service water intake structure.
The license conditions require that the licensee conduct the monitoring program discussed in Section 2.5.4.10.6.2 of the Final Safety Analysis Report (FSAR).
The following is a summary of the license conditions: License Condition 2.c.(5).a requires monitoring of vertical and - horizontal movement of the service water pond west embankment at four points in the vicinity of service water pumphouse and intake structure.
License Condition 2.c.(5).b requires monitoring the submerged profile - of the west embankment over the intake structure.
License Condition 2.c(5).c specifies the frequency of the above - inspections to be in accordance with Regulatory Guide (RG) 1.127 Inspection of Water-Control Structures Associated with Nuclear Power Plant * . . , .
License Condition 2.c(5).d requires inspection of the intake structure - I to detect any new cracks or changes to old grouted or ungrouted cracks.
The maximum inspection interval for the monitoring is five years.
License Condition 2.c.(5).e requires additional inspection of the - intake structure following the operating basis earthquake (0BE).
f The inspector examined procedures which implement the above License Conditions and FSAR committments.
These procedures are Appendices to the SCE&G Survey Monitoring Manual, and Civil Maintenance Procedures (CMP).
The following procedures were examined: a.
Appendix A Settlement Monitoring.
This procedure specifies requirements for monitoring the settlement of the service water pumphouse, intake structure, and duct banks at a frequency of twice a year, b.
Appendix B Elevation / Alignment Monitoring.
This procedure specifies requirements for monitoring the elevation and alignment of the west embankment and north and south dams per the frequency specified in Regulatory Guide 1.127, Inspection of Water-Control Structures Associated with Nuclear Power Plants.
c.
Appendix C Slope Survey, West Embankment Slope.
This procedure specifies requirements for monitoring the submerged embankment slope in the vicinty of the intake structure, d.
Appendix D Diver's Inspection.
This procedure specifies inspection requirements and methology to be used by divers when performing underwater inspections of the intake structure once every five years, or after an OBE.
e.
Appendix E Dam Inspection.
This procedure specifies requirements for inspecting the service water pond embankments (dams) in accordance with RG 1.127.
f.
CMP 700.001, Survey Monitoring.
This procedure contains technical requirements for site surveys to be performed to comply with license conditions and FSAR comitments.
g.
CMP 700.002, Survey Equipment Calibration.
This procedure contains requirements for calibration and maintenance of survey equipment used in peforming the site surveys.
The inspector performed a review of records documenting results of surveys and inspections performed in accordance with the above listed procedures.
The following records were examined: ,
-...... .... _ ... . ... <, , .
Results of service water pumphouse and intake structure settlement - surveys performed between August 1982 and August 1989. Review of the data disclosed that the survey results were evaluated by the licensee's consultants, Gilbert Associates and Woodward Clyde.
Consultants.
The settlement of these structures was negligible during this period.
The inspector noted that any errors in survey data were promptly identified and frequency of the survey was increased af ter errors had occurred to verify that the structures had not settled.
Results of service water dam inspection performed in October 1986.
- No significant problems were noted during the 1986 inspection.
Some minor maintenance problems were identified, e.g., erosion of slopes due to rainfall runoff which were promptly corrected.
The next dam inspection is scheduled to be perfomed in 1991 to comply with the frequency specified in RG 1.127.
Dyrdon Diving Company report summarizing results of October 1988 - inspections of service water intake structure, and Gilbert Associates November 23, 1988, letter which contains an evaluation of the inspection. No significant problems were identified.
Results of submerged embankment slope monitoring performed in the - vicinity of the intake structure between 1981 and 1986.
Conditions of the embankment slope have not changed.
Based on the review of the above procedures and records, the inspector concluded that the licensee is complying with License Conditions 2.c(5).athrough2.c(5)c.
Within the areas inspected, no deviations or violations were identified.
Exit Interview The inspection scope and results were summarized on February 2, 1990, with those persons indicated in paragraph 1.
The inspector described the areas inspected and discussed in detail the inspection results.
Proprietary information is not contained in this report.
Dissenting comments were not received from the licensee. }}