ML20245K564
| ML20245K564 | |
| Person / Time | |
|---|---|
| Site: | Grand Gulf  |
| Issue date: | 06/28/1989 |
| From: | Kintner L Office of Nuclear Reactor Regulation |
| To: | Cottle W SYSTEM ENERGY RESOURCES, INC. |
| References | |
| TAC-71863, NUDOCS 8907050172 | |
| Download: ML20245K564 (7) | |
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g June 28, 1989 DicketNo.50-416
' DISTRIBUTION Docket + File-OGC NRC & Lccal PDRs PAnderson Mr. W. T. Cottle PDII-1 Reading LKintner Vice President, Nuclear Operations SVarga Edordan System Energy Resources, Inc.
Glainas BGrimes Post Office Box 469 EAdensam ACRS(10)
Port Gibson, Mississippi 39150 GRAND GULF FILE
Dear Mr. Cottle:
SUBJECT:
GRAND GULF fiUCLEAR STATION, UNIT 1, AUDIT OF PIPE SUPPORT CALCULATIONS (TACNO.71863)
As a. result of an audit of the Grand Gulf Nuclear-Station (GGNS) Unit 1 pipe support calculations on Harch 20, 1989, the staff raised several questions.
System Energy Resources, Inc. (SERI) provided answers to these questions. The NRC staff's evaluation of these responses is attached as Enclosure 1.
As indicated in Enclosure 1, additional information is needed t'o satisfactorily respond to the audit questions. Additional items for discussion are listed in.
As discussed with your personnel on June 27, 1989, a member of our staff, Mark Hartzman and our consultant, Frank Vasiliadis (Engineering Analysis Services, Inc.) will visit GGNS Unit 1, on July 10 - 14, 1989 for the purpose of auditing pipe support calculations in the areas identified in Enclosures 1 and'2.
You are requested to make available your personnel, design calculations, and supporting material to respond in these areas and in other areas that may arise during the audit.
The reporting and/or recordkeeping requirements of this letter affect fewer than 10 respondents; therefore, OMB clearance is not required under P.L.96-511.
Sincerely, Original signed by Lester L. Kintner, Senior Project Manager Project Directorate'I1-1 Division of Reactor Projects I/II Office of Nuclear Reactor Regulation
Enclosures:
As stated cc w/ enclosures:
See next page
[GGNS-1 AUDIT OF PIPE SU P LTR]
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l Mr. W. T. Cottle System Energy Resources, Inc. -
Grand Gulf Nuclear Station (GGhS) cc:
Mr. T. H. Cloninger Mr. C. R. Hutchinson Vice President, Nuclear Engineering GGNS General Manager
& Support System Energy Resources, Inc.
System Energy Resources, Inc.
P. O. Box 756 P. O. Box 31995 Port Gibson, Mississippi 39150 Jackson, Mississippi 39286 Robert B. McGehee, Esquire The Honorable William J. Guste, Jr.
Wise, Corter, Child, and Attorney General Caraway Department of Justice P. O. Box 651 State of Louisiana Jackson, Mississippi 39205 Baton Rouge, Louisiana 70804 Nicholas S. Reynolos, Esquire Office of the Governor Bishop, Liberman, Cook, Purcell State of Mississippi dnd Reynolds Jackson, Mississippi 39201 1400 L Street, N.W. - 12th Floor Washington, D.C.
20005-3502 Attorney General Gartin Building Mr. Ralph T. Lally Jackson, Mississippi 39205 Manager of Quality Assurance Entergy Services, Inc.
Mr. Jack McMillan, Director P. O. Box 31995 Division of Solid Waste Management Jackson, Mississippi 39286 Mississippi Department of Natural Resources P. O. Box 10385 Mr. John G. Cesare Jackson, Mississippi 39209 Director, Nuclear Licensing System Energy Resources, Inc.
Alton B. Cobb, M.D.
P. O. Box 469 State Health Officer Port Gibson, Mississippi 39150 State Board of Health P. O. Box 1700 Mr. C. B. Hogg, Project Manager Jackson, Mississippi 39205 Bechtel Power C1rporation P. O. Box 2166 President Houston, Texas 77252-2166 Claiborne County Board of Supervisors Port Gibson, Mississippi 39150 Mr. H. O. Christensen Senior Resident Inspector Regional Administrator, Region II U.S. Nuclear Regulatory Comission U. S. Nuclear Regulatory Connission Route 2, Box 399 101 Marietta Street Port Gibson, Mississippi 39150 Sui'.e 2900 Atlanta, Georgia 30323 l
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NRC Staff Evaluation and Requests for Additional Information (RAI) Regarding l
SERI Responses to Questions Listed on Audit Question Forms (AQR) and Requested During the March 20 - 23, 1989 Audit.
i 1.
AQF 89/001. - Forces Due,to Movements in Unrestrained Directions Evaluation:
The response did not address consideration of friction forces: the lower bound for pipe temperature and pipe movement for which the friction needs to be considered.
RAI:
Provide documentation and examples of how friction forces have been considered.
2.
AQF 89/002 - Consideration of Component Stiffnesses in the Pipe Support Evaluation Evaluation:
5 Stiffness of a small size strut / snubber may be as low 1.5 x 10 lb/in.
When combined with stiffness listed in Table 10 of Specification 9645-M-300.2 the results nmy be nonconservative.
RAI:
e Assess the impact of not including the stiffnesses of component standard supports in the analysis.
3.
AQF 89/003 Rev 1 - Information Transfer Between Design Groups Evaluation:
During the audit it was found that:
In two cases there was no record of correspondence between the Pipe Support and the Civil / Structural Group concerning evaluation of embedded plates.
d In two cases the latest stress 4 alysis loads were not incorporated in the pipe support calculations (l.,CR-0049-89).
In two cases the actual pipe support flexibility was larger than the allowable values and approved by the stress analysis group, but there was no evidence that it was properly addressed in the pipe stress a nalysis.
RAI:
(a) Provide information on the corrective action regarding the above cases and describe a program by which the impact of such occurrences will be assessed.
(b) Provide answers to the following questions:
A What was the formal interface in the original design process between Pipe Support, Civil / Structural and Pipe Stress Groups?
How did the Stress Group handle support stiffness deviations?,
What was the procedure for handling interfaces on integral weided attachments per Bechtel Specification 9645-M-300.2, Section 5.8.6.
4.
AQF 89/004 Bolt Prying Action Evaluation:
The SERI response that the method of treating prying action was provided in its January 9,1980 response to IE Bulletin 79-02 is not a sufficient response to close the issue. During a recent inspection by Region II the documentation indicating NRC approval of ~ the licensee's January 9,1980 assessment of p ing action could not be found (NRC Inspection Report No. 50-416/89-10 RAI:
Provide a copy of the User's Manual for the CE-050 Computer Program which was stated to include prying action.
NRC Walkdown of Random Pipe Supports 5.
AQF 89/005 Evaluation:
Staff reviewed the pipe support calculation packages for large pipe supports selected during a walkdown.
RAI:
None
-oj 1
Calculations for Weldments at Obtuse Angles 6.
AQF 89/006 Evaluation:
2 SERI referred to Specification 9645-N-300.6, Paragraph 6.2.2 and Bechtel document QAR-F099 dated August 30, 1979 and Procedure PA-1.
RAI:
Provide the above documents as the supporting documentation to the statement made to the auditors. Similar information should be provided for weldments at acute angles.
7.
AQF 89/007 Consideration of Deadweight of Structural Steel Evaluation:
The staff reviewed the material provided by the licensee as to how deadweight of structural steel was considered in the evaluation of pipe supports and found it acceptable.
RAI:
Nore Method of Calculating Flexibility 8.
AQF 89/008 Evaluation:
The staff questioned whether the method of calculating flexibility by application of total design loads on the support frame was appropriate.
Both the parametric study and the analysis of 31 specific supports disclose large variance in stiffnesses calculated by the multi-directional method and by the unit load method.
In the study, 9 out of the 31 supports have stiffnesses which vary by more than 50 percent. However, the licensee l
claims that the stiffness values are within 10 percent variance from the calculated values and none exceed a 50 percent acceptable variance from the calculated values.
RAI:
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For the above study:
(a) The licensee should explain how variance was calculated.
(b) Provide the documentation necessary to support the claim that the rigid range of equipment starts at the frequency of 20 Hz.
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. (c) Select three systems and perform stress analysis for the piping to investigate the effect of discrepancy in stiffness calculated by the two methods (K1, KC1, K2 and KC2) on the piping stresses and on the pipe supports. The systems selected should contain the pipe supports which have large ratios of the stiffnesses and should be approved by the staff before stress analyses are made.
l 9.
Miscellaneous Questions Evaluation:
The following items have been discussed with the SERI staff and inforr.ation was requested during the audit without being listed on the Audit Question Forms (AQF). SERI did not respond in satisfactory manner.
RAI: Provide information for the following calculations:
(a) Calculation Q1821G02GR06 Rev. D dated 12-10-81 Provide the effect of half of the snubber weight and the frame, applied as a concentrated load to the pipe, on the adjacent supports in case of a seismic event.
(b) Calculation Q1E21G001C03 Rev. B dated 3-17-80 Justify the reouction in expansion bolt capacity due to edge distance which was found in violation of the requirements of Specification Q645-C-103.1, paragraph 3.2-6.
(c) Calculation Q1E61G11CA01 Rev. I dateo 10-28-81 Provide the latest calculation package to verify that the moments predicted by the stress analysis were considered in qualification of the anchor bolts.
(d) Calcuation Q1E22G003H02 Rev. C dated 7-10-81 Provide the latest support drawings to verify that an additional load from the support the calculation was reflected on the support drawing.
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ADDITIONAL AREAS TO BE REVIEWED DURING THE FORTHCOMING AUDIT AT THE GGN5 UNIT 1 1.
Verify the information pertaining to the parametric study of pipe support stiftness.
2.
Verify the data used for the snubbers reduction program.
3.
Verify if the Class I pipe support calculations are available for the Main Steam Line and Recirculation Line. Check methodology, criteria and results.
4.
Verify punching shear in tubing connections.
5.
Verify load combinations at pipe anchors performed by the Civil Group.,
6.
Checkifthelateralloadsduetothermalexpansionofpipingwereconsidered.
7.
Reguest.that a comparison of typical base plates be made for flexibility effects by using CE-050 and ME-035 computer programs to determine the effect of prying action.
8.
Verify consideration of seismic loads in pipe support structural frame calculations.
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