ML20138J460
| ML20138J460 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 12/06/1985 |
| From: | Williams N CYGNA ENERGY SERVICES |
| To: | Counsil W TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC) |
| References | |
| 84056.097, NUDOCS 8512170527 | |
| Download: ML20138J460 (19) | |
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101 Cahfornia Street Suite 1000, San Francis::o, CA 9"11-5894 415 397-5600 December 6, i985 84056.097 Mr. W.G. Counsil Executive Vice President Texas Utilities Generating Company Skyway Tower 400 North Olive Street, L.B. 81 Dallas, Texas 75201
Subject:
Review issues List (RIL)
Texas Utilities Generating Company Comanche Peak Steam Electric Station independent Assessment Program - All Phases
References:
1.
N.H.
Williams (Cygna) letter to W.G.
Counsil (TUGCO), "Cygna Ouestions/ Comments on the CPRT Plan," 84056.085, October 6,1985.
2.
N.H. Williams ~ (Cygna) letter to W.G. Counsil (TUGCO), "Information Requests - Pipe Stress Analyses," 84056.086, October 9,1985.
3.
N.H. Williams (Cygna) letter to W.G. Counsil (TUGCO), " Pipe Stress Review Questions," 84056.093, dated October 28,1985 4.
N.H. Williams (Cygna) letter to W.G. Counsil (TUGCO)," Review issues List (RIL)," 84056.095, dated November 26,1985
Dear Mr. Counsil:
Enclosed is the current revision to the Pipe Stress Review issues List (RIL). All significant changes are noted by a revision bar in the right margin. Most of the revisions were made to provide changes in accordance with the Cygna questions and comments on the CPRT Plan (Reference 1) and information requests made in the open items letters (References 2 and 3).- The current revisions to all other discipline RILs were submitted in Reference 4. The current revision numbers and letter references are as follows:
3 00,I' I
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8512170527 851206 PDR ADOCK 050 5
A San Francisco Boston San Diego Chicago Rechtand
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Mr. W.G. Counsil December 7,1985 Page 2 Discipline Revisions Cygno letter reference Pipe Stress 2
84056.097 Pipe Supports 2
84056.095 Mechanical Systems 3
84056.095 Electrical /l&C 3
84056.095 Cable Troy Supports 12 84056.095 Conduit Supports 3
84056.095 Design Control 2
84056.095 If there are any questions, please call at your convenience.
Very truly yours, dd, g
N.H. Williams Project Manager Attachment cc: Mr. V. Noonan (USNRC) w/ottochments
- Ms. A. Vietti-Cook (USNRC) w/ottochments' Mr. S. Treby (USNRC) w/ottochments Mr. W. Horin (Bishop, Liberman, et al.) w/ottochments Mr. J. Redding (TUGCO) w/ottochments Mr. J. Finneran O UGCO) w/ottochments Mrs. J. Ellis (CASti) w/ottochments Mr. D. Pigott (Orrick, Herrington & Sutclif fe) w/ottochments Mr. F. Dougherty (TENERA) w/ottochments Mr. R. Ballard (Gibbs & Hill) w/ottochments Mr. R. Kissinger (TUGCO) w/ottochments Mr. J. Beck (TUGCO) w/ottochments
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12/06/85 Revision 2 Page 1 PIPE STRESS Review Issues List 1.
Mass __ Participation / Mass Point Spacing
References:
1.
R.E. Ballard (G&H) letter to J.B. George (TUGC0), " Mass-Participation," GTN-69454, September 14, 1984 2.
N.H. Williams (Cygna) letter to J.B. George (TUGCO),
" Phase 3 Open Items - Mass Participation," 84042.017, September 21, 1984 3.
N.H. Williams (Cygna) letter to J.B. George (TUGCO),
" Phase 3 Open Items - Mass Participation," 84042.019, October 2, 1984 4.
L.M. Popplewell (TUGC0) letter to N.H. Williams (Cygna)
"Cygna Potential Finding Report Mass Participation and the Mass Points Spacing Error in Problem AB-1-61A,"
December 7, 1984 5.
N.H. Williams (Cygna) letter to J.B. George (TUGCO),
" Phase 3 Open Items - Mass Participation and Mass Point Spacing," 84042.021, February 8, 1985 6.
Cygna Phase 3 Final Report, TR-84042-01, Revision 1, Observation PI-00-05, and PFR-01 7.
N.H. Williams (Cygna) letter to W.G. Counsil (TUGCO),
"Cygna Questions / Comments on the CPRT Plan", 84056.085, 1
October 6, 1985.
Summary:
The pipe stress seismic analyses did not include sufficient modes to comply with the FSAR, which requires that the in-clusion of additional higher order modes should not increase system response by more than 10%.
In addition, the mass point spacing for the dynamic analyses did not always meet the project criteria.
Status:
This issue remains open. Reference 5 documents Cygna's eva-luation of the Gibbs & Hill piping reanalyses and lists recommended actions. TUGC0/Gibbs & Hill has not responded to the comments in Reference 5.
However, it is expected that this issue will be addressed during Stone & Webster's Piping Reanalysis effort as part of the CPRT Program..Cygna g
has not yet received the Stone & Webster criteria, checklists and procedures which indicate how resolution of this issue will be incorporated into the reanalyses.
Texas Utilities Generating Company Comanche Peak Steam Electric Station L
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Independent Assessment Program - All Phases 111111111111111111111111111111 Job No. 84056
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12/06/85 Revision 2 Page 2 PIPE STRESS Review Issues List 2.
Incorrect Pipe Schedule Used for Calculation of Nozzle Allowables Re ference:
1.
Cygna Phase 1 and 2 Final Report, TR-83090-01, Revision 0, Observation PI-02-05 Summary:
Cygna noted one instance in which the nozzle allowables were calculated using an incorrect wall thickness.
Status:
This issue is closed, based on expanded review to include the pumps on the diesel generator system.
3 ~.
Finite Element Model Error in Flued Head Analysis
Reference:
1.
Cygna Phase 1 and 2 Final Report, TR-83090-01, Revision 0, Observation PI-03-01 Summary:
The flued head finite element model was found to contain a geometry error due to improper generation of some elements.
Status:
This issue is closed, based on review of 15 of the remaining 18 flued head analyses.
4.
Inclusion of Fluid and Insulation Weight at Valves and/or Flanges
Reference:
1.
Cygna Phase 3 Final Report, TR-84042-01, Revision 1, Observation PI-00-04 and Section 5.1., Page 5-6 2.
N.H. Williams (Cygna) letter to W.G. Counsil (TUGC0),
"Cygna Questions / Comments on the CPRT Plan", 84056.085, C
October 6, 1985.
Summary:
Cygna found that it was Gibbs & Hill's standard practice not to include fluid and insulation weight at valves and flanges.
Texas Utilities Generating Company Comanche Peak Steam Electric Station L
i ji i-Independent Assessment Program - All Phases lill::l;liiiiiiii::
Job No. 84056
's 12/06/85 Revision 2 e
Page 3 PIPE STRESS Review Issues List Status:
This issue is closed for the CCW system, based on a Gibbs &
Hill study which demonstrated that the effect is minor. The effects must still be considered in a cumulative effects review. However, it is expected that this issue will be addressed during Stone & Webster's Piping Reanalysis effort as part of the CPRT Program. Cygna has not yet received the g
Stone & Webster criteria checklists and procedures which s
indicate how resolution of this issue will be incorporated into the reanalyses.
5.
Discrepancies.in Pipe Support Loads-Between Analyses and Support Design
References:
- 1.. Cygna Phase 3 Final Report, TR-84042.01, Revision 1, Observation PI-00-06 2.
L.M. Poppelwell (TUGCO) letter to N.H. Williams (Cygna) dated August 29, 1984 3.
R.E. Ballard (Gibbs & Hill) letter to J.B. George (TUGCO), GTN-69233, dated July 10, 1984 4.
Communications Report between J. Finneran (TUGCO), N.
Williams and J. Minichiello (Cygna) dated 7/13/84, 2:45 p.m.
Summary:
Cygna found that, in some instances, the latest support loads were not used in the pipe support design calculations.
Status:
This issue is closed, except as input to the cumulative effects review.
6.
Snubbers on Fisher Valves
References:
1.
Cygna Phase 3 Final Report, TR-84042-01, Revision 1, Observation PI-00-07 and PFR-02 2.
L.M. Popplewell (TUGCO) letter to N.H. Williams (Cygna) dated July 9, 1984 3.
L.M. Popplewell (TUGCO) letter to N.H. Williams (Cygna) dated August 29, 1984 Texas Utilities Generating Company Comanche Peak Steam Electric Station L
LL i Independent Assessment Program - All Phases 11111111111111111111111111111l Job No. 84056 I
12/06/85 Revision 2 Page 4 PIPE STRESS Review Issues List 4.
L.M. Popplewell (TUGC0) letter to N.H. Williams (Cygna) dated October 2, 1984.
A 5.
Communications Report between R. Manvelyan (Gibbs &
Hill) and J. Minichiello (Cygna) dated 6/15/84, 10:30am.
Summary:
The snubbers on the Fisher valve operators were not qualified for the as-built loads. This issue led to questioning whether the valve itself was capable of transmitting these loads and still maintaining operability.
Status:
This issue is closed, based on TUGC0's requalification of all affected valves and snubbers. Cygna has not, however, reviewed the qualification report. TUGC0 should provide a sample Fisher valve qualification report for review.
7.
Snubbers Close to Equipment Nozzles
Reference:
1.
Cygna Phase 4 Pipe Stress Walkdown Checklists (not issued)
Summary:
Cygna noted several snubbers on the Component Cooling Water System (CCW) which were located close to equipment nozzles.
Due to their proximity to a rigid attachment point, the dy-namic displacements at these locations will be very small, such that the snubbers may not perform their intended func-tion.
Status:
This issue is closed with Cygna's recommendation that these snubbers be candidates for a snubber elimination program.
8.
Lack of Traceability for ANSYS/Relap Runs
Reference:
1.
Communications Report between S. Lim (Gibbs & Hill) and L. Weingart (Cygna) dated 3/8/84, 8:45 a.m.
2.
Communications Report between H. Mentel (Gibbs & Hill) and J. Minichiello (Cygna) dated 3/13/84, 3:00 p.m.,
Revision 1 3.
Communications Reports between S. Lim (Gibbs & Hill) and L.Weingart (Cygna) dated 3/15/84, 8:15 a.m.
Texas Utilities Generating Company Comanche Peak Steam Electric Station L
L.L A.
Independent Assessment Program - All Phases litillfilllllimilllillililli Job No. 84056
i 12/06/85 Revision 2 Page 5 PIPE STRESS Review Issues List Summary:
There are four programs utilized by Gibbs & Hill in performing a steam hammer analysis:
1.
RELAP 2.
GHFORCE - provides imbalance loads 3.
Program to convert to ANSYS format 4.
ANSYS Sufficient documentation did not exist to provide cross referencing of the four runs for a particular Main Steam loop.
Status:
This fin ~ ding was closed technically; however, it remains open from a QA standpoint. This issue is being addressed as part of Cygna's Phase 4 design input control review.
9.
Inclusion of Support Mass In Pipe Stress Analysis Re ferences:
1.
Communications Report between G. Krishnan (Gibbs & Hill SSAG) and J. Minichiello (Cygna) dated 3/19/84, 8:30 a.m.
2.
Gibbs & Hill letter GTN-68852 dated April 25, 1984 3.
Communications Report between H. Mentel (Gibbs & Hill),
G. Grace (EBASCO), N. Williams and L. Weingart (Cygna) dated 5/24/84, 10:00 a.m.
4.
Prefiled Testimony of Nancy _ H. Williams, Response to Doyle Question #4, June 12, 1984 5.
Cygna Phase 1 and 2 Final Report, TR-83090-01, Revision 0, Pipe Stress Checklist General Note 1 6.
Communications Report between D. Wade (TUGCO) and N.
Williams (Cygna) dated 10/11/84, 4:00 p.m.
Texas Utilities Generating Company Comanche Peak Steam Electric Station L
i ;L 4 Independent Assessment Program - All Phases lililllilllilllillllllilllilli Job No. 84056
12/06/85 Revision 2 Page 6 PIPE STRESS Review Issues List 7.
N.H. Williams'(Cygna) letter to V. Noonan (USNRC),
84042.022, dated January 18, 1985 "Open Items Associated with Walsh/Doyle Allegations" 8.
N.H. Williams (Cygna) letter to W.G. Counsil (TUGCO),
jg "Cygna Questions / Comments on the CPRT Plan", 84056.085, October 6, 1985.
Summary:
The weight of the pipe supports was included in the stress analyses for the Main Steam Inside Containment only.
In Reference 1 Cygna requested justification for this prac-tice. Gibbs & Hill responded in Reference 2 by pointing out that the supports associated with the Main Steam lines were relatively massive and, as such, a judgement was made to include their mass in the stress analysis. 'For other systems, a judgement was made that the effects would be negligible. Per Reference 4 the effect of this omission on support loads was shown to be as high as 24% on the RHR system.
However, it is expected that this issue will be addressed during Stone & Webster's Piping Reanalysis effort as part of j{g the CPRT Program. Cygna has not yet received the Stone &
Webster criteria, checklists and procedures which indicate-how resolution of this issue will be incorporated into the reanalyses.
Status:
In the context of the CPRT Plan, TUGC0 should demonstrate that support mass effects have been considered in the pipe stress analysis.
- 10. Stress Intensification Factors (SIFs)
References:
1.
Cygna Phase 1 and 2 Final Report, TR-83090-01, Revision 0, Observation PI-00-01 2.
Cygna Phase 3 Final Report, TR-84042-01, Revision 1, Observation PI-00-01 3.
N.H. Williams (Cygna) letter to W.G. Counsil (TUGCO),
/ki "Cygna Questions / Comments on the CPRT Plan", 84056.085, October 6, 1985.
Texas Utilities Generating Company Comanche Peak Steam Electric Station LJL A Independent Assessment Program - All Phases L
181111416111111111111111111111 Job No. 84056
12/06/85 Revision 2 Page 7 PIPE STRESS Review Issues List Summary:
Cygna found numerous instances where Gibbs and Hill either neglected to input the required SIF into the stress analysis (References 1 & 2) or miscalculated the SIF (Reference 2).
Status:
This issue is closed, based on expanded reviews. However, it is expected that this issue will be addressed during Stone & Webster's Piping Reanalysis effort as part of the g
CPRT Program.
Cygna has not yet received the Stone &
Webster criteria, checklists and procedures which indicate how resolution of this issue will be incorporated into the reanalyses.
- 11. Welded Attachments
References:
1.
Cygna Phase 1 and 2 Final Report, TR-83090-01, Revision 0, Observation PI-00-02 and PI-02-03 2.
Cygna Phase 3 Final Report, TR-84042-01, Revision 1, Observations PI-00-02 and PI-06-01 3.
N.H. Williams (Cygna) letter to W.G. Counsil (TUGCO),
"Cygna Questions / Comments on the CPRT Plan", 84056.085, October 6, 1985.
Summary:
Cygna found several problems with Gibbs and Hill's treatment of welded attachments:
o An increased allowable was used in the evaluation of local stresses for upset and emergency combinations (Reference 1).
o Thermal expansion loads were used rather than load ranges for evaluation of local stresses (Reference 1).
o Local stresses were not considered in break exclusion zones (Reference 2).
o Combined effects of two supports at a single welded attachment were not considered (Reference 2).
Texas Utilities Generating Company Comanche Peak Steam Electric Station L
iJL A Independent Assessment Program - All Phases 18104148l11111111111lll1111111 Job No. 84056
12/06/85 Revision 2 Page 8 PIPE STRESS Review Issues List Status:
This issue is closed, based on the use of rationale from later codes, recalculations, and expanded reviews. However, it is expected that this issue will be addressed during Stone & Webster's Piping Reanalysis effort as part of the CPRT Program. Cygna has not yet received the Stone &
checklists and procedures which indicate Webster criteria,f this issue will be incorporated into the how resolution o reanalyses.
- 12. Use of Incorrect' Pipe Wall Thickness
Reference:
1.
Cygna Phase 1 and 2 Final Report TR-83090-01, Revision 0, Observation PI-01-01 Summary:
Cygna found two piping segments which were input to the stress analysis with the incorrect wall thickness.
Status:
This problem is considered isolated and closed, based on Cygna's recalculation of the pipe stresses.
13.
Inclusion of Appropriate Response Spectra
References:
1.
Cygna Phase 1 and 2 Final Report. TR-83090-01, Revision 0, Observation PI-02-01 Sumiary:
Cygna noted that stress analysis problem AB-1-70 did not consider all the appropriate response spectra from all buildings.
Status:
This issue is closed, based on an evaluation of the omitted spectra and an expanded review to determine if this situation occurred in other stress problems.
Texas Utilities Generating Company Comanche Peak Steam Electric Station L
Lj6 A Independent Assessment Program - All Phases 181111111lll111111mllllll111 Job No. 84056 I
12/06/85 Revision 2 Page 9 PIPE STRESS Review Issues List
- 14. Support Location Discrepancy
References:
1.
Cygna Phase 1 and 2 Final Report, TR-83090-01, Revision 0, Observation PI-02-02 2.
Cygna Phase 3 Final Report, TR-84042-01, Revision 1 Checklist PI-09, Item 14 Summary:
Supports were modeled at locations outside of allowable tolerances. The Reference 1 observation was closed based on an evaluation of the pipe stresses and an assessment that these occurrences were sufficiently isolated. The Reference 2 discrepancy was noted and evaluated by Gibbs & Hill in their QA binder.
Status:
This issue is closed.
- 15. Use of Incorrect Damping in Seismic Analyses Refennce:
1.
Cygna Phase 3 Final Report TR-84042-01, Revision 1, Observation PI-00-03 2.
N.H. Williams (Cygna) letter to W.G. Counsil (TUGCO),
g "Cygna Questions / Comments on the CPRT Plan", 84056.085, October 6, 1985.
Summary:
Cygna noted that Gibbs & Hill did not consider the lower damping response spectra in some systems with both large and small bore piping.
Status:
This issue is closed, based on Cygna's expanded review.
However, it is expected that this issue will be addressed during Stone & Webster's Piping Reanalysis effort as part of the CPRT Program. Cygna has not yet received the Stone &
Webster criteria, checklists and procedures which indicate b
how resolution of this issue will be incorporated into the reanalyses.
Texas Utilities Generating Company Comanche Peak Steam Electric Station LN i ; L 4
Independent Assessment Program - All Phases 181111166111!!111111111111llll Job No. 84056
12/06/85 Revision 2 Page 10 PIPE STRESS Review Issues List
- 16. Combination of Safety / Relief Valve Thrust and Seismic Loads
Reference:
1.
Cygna Phase 3 Final Report, TR-84042-01, Revision 0, Observation PI-06-02 Summary:
In pipe stress problem AB-1-23B, the stresses / loads due to safety / relief valve thrust were not combined with those due to SSE for the emergency case.
In the other three Main Steam lines outside containment, the two effects were combined. While not specifically required by the FSAR, Cygna believes it is appropriate to combine the two effects.
Status:
ds part of the overall-review for other_ effects, TUGC0 should demonstrate the piping and supports on this line are acceptable under the combined loading.
17.
Force Distribution in Double Ported Safety Valves
Reference:
1.
Communication Report between H. Mentel (Gibbs & Hill) and J. Minichiello (Cygna) dated 3/12/84, Item 2b 2.
N.ll. Williams (Cygna) letter to W.G. Counsil (TUGCO),
g "Cygna Questions / Comments on the CPRT Plan", 84056.085, October 6, 1985.
Summary:
By assuming a 55/45 split in the flow, instead of the 60/40 suggested by Crosby Valve as general practice, the torque on the Main Steam pipe is halved.
Status:
TUGC0 should demonstrate that the 55/45 split is a reasonable assumption.
In addition, if the 55/45 split is not a reasonable assumption, TUGC0 should address the implication this has on the Main Steam lines and any other lines which use double ported safety valves.
It is expected that this issue will be addressed during Stone & Webster's Piping Reanalysis effort as part of the h
CPRT Program. Cygna has not yet received the Stone &
Webster. criteria, checklists and procedures which indicate how resolution of this issue will be incorporated into the reanalyses.
l Texas Utilities Generating Company Comanche Peak Steam Electric Station L
Lj6 A Independent Assessment Program - All Phases mHmilmmmHmilml Job No. 84056
12/06/85 Revision 2 Page 11 PIPE STRESS Review Issues List
- 18. Fisher Valve Modeling
Reference:
1.
Communication Report between H. Mentel (Gibbs & Hill) and J. Minichiello (Cygna) dated 3/12/84, Item Ic 2.
Communication Report between Krishnan/ Ray (Gibbs & Hill) and Minichiello (Cygna) dated 6/12/84 3.
N.H. Williams (Cygna) letter to W.G. Counsil (TUGCO),
g "Cygna Questions / Comments on the CPRT Plan", 84056.085, October 6,1985.
Sunenary:
Cygna has questions on the modeling of " flexible" valves (F < 33 cps).
In the review, Cygna found that valves noted in Reference 2 (other than Fisher valves) were the only
" flexible" valves within the Gibbs & Hill scope. Cygna determined that the valve accelerations for those valves were acceptable; however, Cygna did not address the modeling of the Fisher valve yoke, which is laterally supported at the end.
If the yoke is modeled much stiffer than it actually is, this may affect the analysis results.
Status:
TUGC0 should demonstrate that the stiffness used to model Fisher valves reasonabl3 approximates the actual valve yoke stiffness. However, it is expected that this issue will be addressed during Stone & Webster's Piping Reanalysis effort A
as part of the CPRT Program. Cygna has not yet received the 13 1 Stone & Webster criteria, checklists and procedures which indicate how resolution of this issue will be incorporated into the reanalyses.
- 19. Eccentric Mass and Its Effect on Piping and Welded Attachments
Reference:
1.
Consnunication Report between G. Krishnan (Gibbs & Hill) and J. Minichiello (Cygna). dated 3/21/84, Item 1 2.
R.E. Ballard, Jr. (Gibbs & Hill) letter GTN-68852 to J.B. George (TUGCO) dated 4/25/84 3.
N.H. Williams (Cy na) letter to W.G. Counsil (TUGCO),
g "Cygna Questions / omments on the CPRT Plan", 84056.085, October 6, 1985.
Texas Utilities Generating Company Comanche Peak Steam Electric Station Independent Assessment Program - All Phases g
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Job No. 84056 111111111111111111111111111lll
12/06/85
.o Revision 2 Page 12 PIPE STRESS Review Issues List Summary:
In modeling the masses of the supports in the Main Steam lines inside containment, Gibbs & Hill did not consider the eccentricity of the mass from the pipe centerline.
In their response in Reference 2, Gibbs & Hill showed that the seismic effects were small on the overall pipe cross-section. They also showed that the local effects at the welded attachment were not significant for a 1.0g load.
Further Cygna review showed that the seismic accelerations were on this order. Cygna's review did not consider the effect of fluid dynamic accelerations, nor other systems.
Status:
TijGC0 should demonstrate that the effect of eccentric masses on the steam hammer results is not significant.
In addi-tion TUGC0 should demonstrate that other piping systems have similar seismic / dynamic stresses due to eccentric masses. However, it is expected that this issue will be addressed during Stone & Webster's Piping Reanalysis effort 2
as part of the CPRT Program. Cygna has not yet received the Stone & Webster criteria, checklists and procedures which indicate how resolution of this issue will be incorporated into the reanalyses.
- 20. ANSYS Steam Hammer Analyses
Reference:
1.
Communication Report between H. Mentel (Gibbs & Hill) and J. M?nichiello (Cygna) dated 's/13/84, Item 2 2.
Communication Report between G. Krishnan (Gibbs & Hill) and J. Minichiello (Cygna) dated 3/21/84, Item 3 3.
R.E. Ballard, Jr. (Gibbs & Hill) letter GTN-68852 to J.B. George (TUGCO) dated 4/25/84 4.
N.H. Williams (Cygna) letter to'W.G. Counsil (TUGCO),
g "Cygna Questions / Comments on the CPRT Plan", 84056.085, October 6, 1985.
Summary:
In reviewing the ANSYS model, Cygna questioned the mass point spacing and time step size used. Gibbs & Hill sup-plied the results of a sensitivity study in Reference 3.
In addition Cygna questioned the load output in two axial re-straints, since they were less than the load input. Gibbs &
Hill explained why the results were reasonable in Reference Texas Utilities Generating Ccmpany Comanche Peak Steam Electric Station L
i 6 A Independent Assessment Program - All Phases 111111111111lllll1161111111111 Job No. 84056
12/06/85 Revision 2 Page 13 PIPE STRESS Review ~ Issues List 3.
Prior to the Reference 3 response, however, Cygna did not find any documentation indicating that either a sensitivity study' had been done or that the ANSYS results had been reviewed for " reasonability".
It is expected that this issue will be addressed during Stone & Webster's Piping Reanalysis effort as part of the CPRT Program. Cygna has not yet received the Stone &
Webster criteria, checklists and procedures which indicate 2
how resolution of this issue will be incorporated into the reanalyses.
Status:
T'UGC0 should demonstrate that any water hamer dynamic analyses have acceptable input and output results.
- 21. Valve Acceleration and Flange Load Generic Studies
Reference:
1.
Cygna Phase 2 Final Report TR-83090-01, Revision 0, Checklist PI-01, Notes 3 and 4 2.
Communication Report between H. Mentel (Gibbs & Hill) and J. Minichiello (Cygna) dated 3/19/84, Item 7 3.
N.H. Williams (Cygna) letter to W.G. Counsil (TUGCO),
A "Cygna Questions / Comments on the CPRT Plan", 84056.085, l.L\\
October 6, 1985.
Summary:
In Phases 1 and 2 Cygna found that Gibbs & Hill did not check valve accelerations or flange loads in every pipe stress calculation.
Instead, Gibbs & Hill used a sampling process, which was reasonable, to determine the worst valves or flanges. They then showed, through two general studies, that all valves met the Specification allowables and that all flanges met Code allowables.
In Phase 3. however, Cygna found one safety valve with an acceleration slightly above (2%) the allowable. This indicates that the sampling method may not be sufficient to address all valves or flanges.
Status:
TUGC0 should demonstrate that all valves and flanges meet i
I appropriate allowables as part of any overall assessment of the piping. However, it is expected that this issue will be addressed during Stone & Webster's Pipin's Reanalysis effort d
as part of the CPRT Program. Cygna has not yet received the Texas Utilities Generating Company Comanche Peak Steam Electric Station L
L.6 A Independent Assessment Program - All Phases lilillillillililllillilillilli Job No. 84056
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12/06/85 Revision 2 Page 14 PIPE STRESS Review Issues List Stone & Webster criteria, checklists and procedures which indicate how resolution of this issue will be incorporated into the reanalyses, b
- 22. LOCA Load Cases
References:
1.
R.E. Ballard (Gibbs & Hill) letter to J.B. George (TUGCO) " Responses to Cygna Energy Services", GTN-70737, October 17, 1985.
Suanry Westinghouse supplied Gibbs & Hill with the displacements at
.the steam generator nozzle during a LOCA event. Two sets of displacements were provided. The first set consisted of the displacements which result from a primary side break in the same loop as the main steam line being analyzed. This was called the " broken loop" case. The second set consisted of the displacements associated with a primary side break on a different loop. This was called the " unbroken loop" case.
Review of the main steam inside containment analyses noted the following:
a.
Two LOCA. load cases were run: unbroken and broken loop.
b.
Unbroken loop loads and stresses were included in the emergency combination, while broken loop was used in the faulted combination.
c.
Broken loop loads and stresses were always higher than unbroken loop loads (as would be expected).
d.
The CPSES FSAR does not specifically require LOCA loads to be considered for the emergency condition.
Status:
This issue is closed.
Per Reference 1, the stress analyst initially assumed that the main steam was an essential system. The CPSES FSAR stctes that essential systems must meet a faulted allowable stress of 1.85 (normally the emergency allowable).
Hence, unbroken loop LOCA was included in the emergency combination. After the stress l
analyst came to the understanding that the main steam was a non-essential system, the unbroken load case was no longer
- run, t
Texas Utilities Generating Company Comanche Peak Steam Electric Station l
L L.6 &
Independent Assessment Program - All Phases lililililililillilili6lillilli Job No. 84056 L
12/06/85 Revision 2 Page 15 l
PIPE STRESS l
Review Issues List
- 23. Line Lists. Modes of Operation and Valve Lists.
References:
1.
Communications Report between Manu Patel (Gibbs & Hill) and J. Oszewski (Cygna) dated 8/1/85.
2.
Communication Report between T. Hawkins (Gibbs & Hill)
/A W
and R. Hess (Cygna) dated 6/7/84,11:00am.
3.
Communications Report between T. Hawkins (Gibbs & Hill) and R. Hess (Cygna) dated 6/7/84, 3:00pm.
4.
N.H. Williams (Cygna) letter to W.G. Counsil (TUGC0),
"Information Requests - Pipe Stress Analyses,"
84056.086, October 9, 1985 Summary:
Review of Gibbs & Hill Project Guide PG-25, dated 3/1/83,
" Procedure for Preparation and Design Review of Line Lists, Modes of Operation and Valve. Lists," indicates that line lists are to be generated on the form included as Exhibit 1 of that procedure. Cygna did not find evidence of this during the reviews conducted at the CPSES site.
- Instead, computer listings apparently were used which did not have all of the infnrmation indicated on Exhibit 1 of PG-25.
Additionally, Cygna could not determine which procedure, if any, controlled the issuance of the computer listings.
Status:
This issue is open, awaiting response to this issue raised in Reference 4.
24 Support Orientation Tolerance
References:
1.
R.E. Ballard (Gibbs & Hill) letter to J.B. George (TUGCO), " Responses to Cygna Energy Services," GTN-70737, October 17, 1985.
Summary:
Cygna could not determine what tolerance, if any, was used for support orientation, (i.e., angle) when performing the as-built stress analysis.
Texas utilities Generating Company Comanche Peak Steam Electric Station 6.
l ;6 6 Independent Assessment Program - All Phases litelllittlilllillnelllilli Job No. 84056
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12/06/85 Revision 2 Page 16 PIPE STRESS Review Issues List Status:
This issue is open. Per Reference 1 an angular tolerance of five degrees was used, based on the manufacturers' permissible misalignment or angular motion. This tolerance was not documented.
Instead, it was communicated verbally to all as-built analysis group leaders, as well as to the
~
individual analysts, by the responsible job engineer.
Cygna has not yet received the Stone & Webster criteria or checklists to determine how this issue will be addressed during the CPRT piping reanalyses.
- 25. Hydrotest Loads References 1.
N.H. Williams (Cygna) letter to J.W. Beck (TUGCO) 84056.064, dated 4/23/85.
" Review Issue List Transmittal". Cygna Pipe Support Review Issues List.
Item No. 14 Revision 1 2.
Gibbs & Hill Specification 2323-MS-200, Revision 3 3.
Communication Reports between J. Minichiello (Cygna) and D. Rencher (TUGCO), dated 3/20/84, 2:00 p.m., Project 84042 4.
L.M. Popplewell (TUGCO) letter to N.H. Williams (Cygna),
dated 4/9/84 5.
N.H. Williams (Cygna) letter to W.G. Counsil (TUGCO),
" Pipe Stress Review Questions," 84056.093, October 28, 1985 Summary:
While reviewing the Cygna pipe stress data base and TUGCO's response to Cygna's comment on Hydrotest Loads (Reference 4), it was necessary to identify under which plant co.dition "hydrotest load" is considered. Gibbs & Hill Specificition 2323-MS-200 Section 5.2.1, states that " testing conditions" are excluded from the Normal Plant Operating Conditions.
In Section 5.2.5a the specification states that " testing conditions" are considered as a normal plant operating condition.
In addition to this discrepancy, Cygna could not determine how the pipe stress and support designs accounted for the hydrotest load condition.
Texas Utilities Generating Company Comanche Peak Steam Electric Station L
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Independent Assessment Program - All Phases 11111111411616114 111111111111 Job No. 84056
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12/06/85 Revision 2 Page 17 PIPE STRESS Review Issues List Status:
This issue is open, awaiting response to Reference f.
In additiu, Cygna has not received Stone & Webster's criteria and checklists to determine how this issue will be addressed-g during the CPRT piping reanalyses.
- 26. Pipe Stress Rev'iew of Welded Attachments
References:
1.
N.H. Williams (Cygna) letter to J.W. Beck (TUGCO) 84056.064, dated 4/23/85.
" Review Issue List Transmittal". Cygna Pipe Stress Review Issue List, item No. 11 Revision 1 2.
N.H. Williams (Cygna) letter to W.G. Counsil (TUGCO),
" Pipe Stress Review Questions", 84056.093, October 28, 1985 Summary:
Based on Cygna's understanding that no formal process was established to allow the pipe stress analyst to review the pipe support designs, it was not possible to determine by which procedure welded attachments were identified for evaluation by the pipe stress analysts.
Status:
This issue is open, awaiting response to Reference 1.
In -
addition, Cygna has not received Stone & Webster's proccdures to determine how this issue will be addressed during the CPRT piping reanalyses.
Texas Utilities Generating Company Comanche Peak Steam Electric Station L.
L;L a Independent Assessment Program - All Phases 111111111111111144861146111111 Job No. 84056