IR 05000280/1979058
| ML18136A258 | |
| Person / Time | |
|---|---|
| Site: | Surry  |
| Issue date: | 10/24/1979 |
| From: | Compton R, Herdt A, Modenos L NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML18136A257 | List: |
| References | |
| 50-280-79-58, NUDOCS 7912050622 | |
| Download: ML18136A258 (5) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION.
Report No. 50-280/79-58
REGION II
101 MARIETTA ST., N.W., SUITE 3100 ATLANTA, GEORGIA 30303 OCT 2 5 1979 Licensee:
Virginia Electric and Power Company Richmond, Virginia 23261 Facility Name:
Surry Docket No. 50-280 License No. DPR-32 Inspection at St~,,,bs~e,r Engineering Corporation, Inspecto¥:
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Approved by:*@"t#
A. R. Herdt, Section Chief, RC&ES Branch SUMMARY Inspection on September, 26-28, 1979 Areas Inspected Boston, Mas ;aj?y/zf Date S'igned 10,d'v/?;1 Date Signed
/t7/i2y/7£ Dale Si'gned J
This special, announced inspection involved 32 inspector-hours onsite in the areas of IE Bulletins, 79-02, "Pipe Support Base Plate Design Using Concrete Expansion Anchor Bolts", and 79-14, "Seismic Analysis for As-Built Safety Related Piping Systems".
Results Of the two areas inspected, no items of noncompliance or deviations were identifie.
Persons Contacted Licensee Employees DETAILS
- W. C. Spencer, Vice President, Power Station Engineering and Construction Services
- C. M. Robinson, Supervisor, Engineering Services
- T. A. Peebles, Superintendent of Technical Services (Surry)
- R. K. MacManus, Project Engineer Other Organizations Stone & Webster Engineering Corporation
- P.A. Wild, Engineering Manager
- S. C. Rossier, Assistant Engineering Manager
- W. H. Chamberlain, Project Technical Advisor
- B. F. Crowe, Project Engineer
- P.R. Pepi, Design Supervisor, Engineering Mechanics Division (EMD)
- J. G. Dyckman, Structural Engineer
- A. L. Van Sickel, Engineer, EMD
- W.R. Curtis, Lead Engineer, Engineering Assurance Division
- Attended exit interview Exit Interview The inspection scope and findings were summarized on September 28, 1979 with those persons indicated in Paragraph 1 abov.
Licensee Action on Previous Inspection Findings Not inspecte.
Unresolved Items Unresolved items are matters about which more information is required to determine whether they are acceptable or may involve noncompliance or deviation New unresolved items identified during this inspection are discussed in paragraph.
IE Bulletins 79-02, "Pipe Support Base Plate Designs Using Concrete Expansion Anchor Bolts" and* 79-14, "Seismic Analysis for As-Built Safety Related Piping Systems."
On September 7, 1979 Region II issued a letter to VEPCO outlining certain actions related to these IE Bulletins that would be performed prior to returning Surry Unit 1 to servic The purpose of this inspection was to
-2-examine licensee actions with regard to items one and three of this lette Item one was an analysis of samples of safety related systems, six inches or less in diameter,to provide assurance that the piping met original design criteria as outlined previously in VEPCO letter serial 72 VEPCO selected four safety injection lines and three reactor coolant lines for analysi These three inch lines were the remainder of safe shutdown piping which had not been previously analyzed during the seismic reanalysis Show Cause Orde This piping had been stress analyzed using simplified
,
(non-computer) methods and no documentation of the original analyses was availabl Isometric drawings were prepared from available piping drawing The installed piping was inspected and the isometrics were marked up as necessary to reflect the as-built condition. As-built drawings were also prepared for pipe support The seven lines, reduced to five stress problems, were dynamically stress analyzed using the "NUPIPE" program for DBE conditions only, without anchor movement This was the same criteria used for the Show Cause Order analyse After determination of support loads, the supports, including baseplates and expansion anchors, were analyze The following pertinent Stone & Webster (S&W) procedures were reviewed:
12846.26-Pl-O, "Procedure for Evaluation of Pipe Support Baseplates Using Concrete Expansion Anchor Bolts" Sketch STD.Z6.1-2, "Earthquake & Thermal Stress Decal" Sketch STD.Z6.2-2, "Thermal Stress Decal" 12846.26-TPl-2, "Technical Procedure for Preparation of Pipe Hanger As-Built Sketches" SD-STEP, Revision O, "Procedure for Evaluation of Base Plates and Drilled-In Anchors"
"Procedure for EMD Review of Isometrics Generated for IE Bulletin 79-14",
Revision 0 Isometrics and stress analysis printouts for safety injection stress prob-lem 3003 and reactor coolant (RC) problem 3001 were examine Flexibility analysis of one support of a total of 14 had been complete The analysis for this support, H-2 in RC problem 3001, was examine The calculated factor of safety for the anchors was 2.4 which meets the acceptability criteria for interim operation detailed in IEB 79-02, Revision 1, Supplement The summaries of piping and. support stresses resulting from all five stress problems were also reviewe Small portions of three 1-\\ inch diameter branch lines, one on each of the reactor coolant lines, had calculated pressure plus dead weight stresses in excess of allowable Two 1-\\ inch diameter and one 1 inch diameter branch lines on two of the reactor coolant lines had calculated pressure plus dead weight plus DBE stresses in excess
-3-of allowable Thermal stresses were within allowable To reduce calcu-lated stresses below the allowables S&W made the following assumptions and reperformed the analyse For the pressure plus dead weight condition the socket weld stress intensification factor of 1.3 was eliminated. Resultant stresses were still slightly above allowables in two of the three branch line For the pressure, dead weight, and DBE condition a 3% damping value was used (1% previously used) and the Amplified Response Spectra "bump
"
factor" of 1.5 was eliminated in addition to the socket weld stress intensification facto Recalculated stresses were within allowable The NRC is evaluating the stress analysis results and the use of these assumptions to reduce calculated stresse Item three of the September 7, 1979 Region II letter was to analyze samples of baseplates including flexibility consideration During the inspection of the original sampling of expansion anchors in accordance with
!EB 79-02 the licensee identified 106 supports that were not fabricated or installed as detailed on available drawing The analysis of these supports includes baseplate flexibility where applicabl At the time of this inspection approximately 22 of these analyses had been complete The inspectors examined the calculations for the following supports:
Line N "-CH-1-1502 12"-SI-45-1502 4"-,RC-14-1502 12"-SI-46-1502 4"-RC-14-1502/4"-RC-16-1502 3"-CH-311-1503 Hanger N H131 H19A & H19B H30 *
H24 H25, H26 H223 These *calculations showed these supports met the required allowable stresses and factors of safety (H223 above met only the interim operability factor of safety of between two and four).
During the support analysis review it was noted that a vertical support and a rod hanger were not included in the thermal analysis and the points of concern had an excessive downward motion of 0. 75" and 1.5 11 respectivel This is not a proper method of analysis when there is downward movemen This particular problem was reanalyzed with the vertical support and rod hanger as vertical restraints in the thermal condition and found that the s'tresses and loads on the supports were still acceptabl The 311 line analyzed was a very flexible system and was able to absorb the additional restraint However, larger thermal movements or less flexible (larger diameter) piping could have significant effects on support loading A spot check of vertical support analysis for the sample stress analysis problems discussed previously indicated that thermal movement had been evaluated by the analys S&W indicated that consideration of thermal effects is part of the normal sound engineering practice that should be exercised by the analys The only procedure provided that addresses this question was a S&W EMD memorandum setting forth "non-mandatory general guidelines" for stress analysis of systems using vertical supports and constraint The apparent inconsistency in considering thermal movement effects on vertical supports is identified as
L
-4-Unresolved Item 280/79-58-0 The licensee was asked to determine the extent and effects of this apparent inconsistenc It was agreed that the licensee would provide a written report of completed actions and results for the items outlined in the Region II letter of September 7, 197 This report is to include justification for the accept-ability of results and the analytical assumptions made in the stress analysis of the sample problems for item one of the RII lette The licensee also,
agreed to keep RII informed of the progress and results of the remaining analyses of the support as-built discrepancie No items of noncompliance or deviations were identified.