ML19208C010
| ML19208C010 | |
| Person / Time | |
|---|---|
| Site: | Trojan File:Portland General Electric icon.png |
| Issue date: | 08/22/1979 |
| From: | Gray J NRC OFFICE OF THE EXECUTIVE LEGAL DIRECTOR (OELD) |
| To: | Mccollom K, Mark Miller, Paxton H AFFILIATION NOT ASSIGNED, Atomic Safety and Licensing Board Panel, OKLAHOMA STATE UNIV., STILLWATER, OK |
| References | |
| NUDOCS 7909240321 | |
| Download: ML19208C010 (9) | |
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-a Marshall E. Miller, Esq., Chairman Dr. Kenneth A. McCollom, Dean Atomic Safety and Licensing Board Division of Engineering, U.S. fiuclear Regulatory Coraission Architecture & Technclogy Washington, DC 20555 Oklahoma State University Stillwater, OK 74074 Dr. Hugh C. Paxton 1229 41st Street Los Alamos, NM 87544 In the Matter of Portland General Electric Company, et al.
(Trojan f;uclear Plant)
Docket t!o. 50-344 (Control Building)
Gentlemen:
Enclosed are additional structural and plarit systems related questions from the Staff to the Licensee with regard to the proposed Control Building modi-fications. These additional questions generally seek clarification of, or additional irdormation and details on, the Licensee's responses to previous Staff questions.
In the interest of expediting transmission, these questions were given to the Licensee orally in a telephone conference call held on Friday,. August 17, 1979.
By means of this letter, these additional questions are being distributed to the parties in the referenced proceeding for their information.
Sincerely, Lf.h f
)'W-f Noseph R. Gray, Cot}nsel for NRC S3 ff
Enclosure:
As stated cc w/cncl:
Service List 883.344 7 0 0924 03d),
ADDITIO AL STRUCTURAL QUESTIONS FROM NRC STAFF 1.
Verify that the computer codes used for the evaluation of piping, cable trays, equipment and components considering the modifications to the Control / Auxiliary / Fuel Building Complex are the same as those referenced in your response to NRC question 1 attached to your letter to the NRC dated November 2, 1978 regarding your reevaluation of the Building Cumplex.
If any other computer codes have been used, state how their accuracy has been verified and that they are appropriate for the analyses in which they have been used.
2.
In your discussion of conformance with the requirements of ACI 349-76 as supplemented by Regulatory Guide 1.142, verify for the non-staggered positive connections that all applicable loadings, including the transverse earthquake and the tornado loadings, were considered in your determination that those connections carrying design load stresses in excess of 0.5 fy are not subject to significant bending moments or tensile forces.
3.
In your discussions of your criteria for studs, only pure shear is con-sidered. State and justify the methods by which both vertical and horizontal tensions resulting from such sources as transverse loadings, shrinkage etc.
were considered.
4.
Provide the vertical natural frequencie: for the complex for the modified Control Building.
In addition, provide sketches of the floor slab at elevation 65' and the connection to the wall being added at column line N' at El. 65' to demonstrate that the addition of this wall aill not non-conservatively affect the originally calculated seismic response of the floor slab.
5.
In the design of the bolts, thermal gradients across the wall were considered.
State and justify the gradients considered for the walls where these bolts are used.and all walls.
How are these gradients factored into your evalu-ation of existing walls and the design of the new walls. What is the maximum bolt tension for any bolt and justify its acceptability. Additionally, the design of the Nelson studs does not consider the thermal gradients, and other loadings as discussed in question 3 of these questions.
Justify this neglect in detail.
6.
Provide the details of the sleeves which wi be used to encase the fire lines under the new railroad spur.
Include the loads, and load combinations and corresponding acceptance criteria for these sleeves, and details of how the loaci were determined.
7.
Describe each different anchorage method in detail where new reinforcement is to be anchored into existing walls and floors. Justify the acceptability of each method including +he adequacy of reinforcement anchorage. Where-ever grout or a siniilarly functioning material is to be used, state its composition, justify its adequacy to perform its intended function, and justify that it will have no deleterious effects on the existing Wall or rebar (such as corrosion).
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. 8.
State and justify the loads, and load combinations and corresponding accept-ance criteria for your evaluations of the modifications being performed to the Turbine iuilding. Verify that torsional considerations were factored into your evaluation where portions of the top and bottom flanges of the steel girder are being removed.
9.
Justify the adequacy of the height: thickness and width: thickness ratios of the insitu walls to substantiate the validity of the unit comparisons between the insitu walls and the test specimen.
- 10. Provide sketches of the horizontal ar.d vertical reinforcement anchorages for all of the test specimens.
- 11. Provide the details of your analyses to determine the tensile forces in the additional walls. Justify all assumptions and procedures.
12.
(a) With regard to your response to question 11 of the Staff's May 18, 1979 questions, discuss the effects of " Tests to Evaluate Coefficient of Static Friction Between Steel & Concrete," by B. G. Rabbat and H. G. Russell, February 1979, at all interfaces where friction is relied upon to transmit load.
This includes, among others, plate interfaces and grade beams. Also, justify the assumption of pure shear behavior for the entire cross-section of the steel columns.
(b) With regard to page 4 of 6 of your response to question lla of the Staff's May 18, 1979 questions, you assumed a column acting in pure shear in your comparison of test results for calculating V1 and V -2 Substantiate that assumption and state the bearing limitation on that calculation. Also provide similar calculations of capacity for specimen L.
1 (c) With regard to page 6 of 6 and the footnote to the table in response to question lla of the Staff's May 18, 1979 questions, what is the shear transfer mechanism between the slab and the wall at elevation 117'? Describe how this was evaluated and justify its adequacy.
- 13. With regard to your response to question 11b of the Staff's May 18, 1979 questions, how was the separation for the west wall along column line R between column lines 41 and 46 and below the bottom flange of the steel beam supporting the floor at elevation 77' factored into the capacity calculations? Justify all assumptions made.
- 14. With regard to your response to question 11d of the Staff's May 18, 1979 questions, what are the ultimate shearing stresses (loads) at the interfaces discussed in this response.
Describe the interfaces and the shear stresses that must be transferred across them.
- 15. With regard to your response to question 14 of the Staff's May 18, 1979 questions, (a) Verify that no flange walls go into tension due to gross overturning.
(b)
Indicate how creep and shrinkage was considered in the dead load calculation.
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. 16. With regard to your resonse to question 19a of the Staff's May 10, 1979 questions, do the concrete block walls (without core) still meet the appropriate UBC requirements? Justify any deviations.
- 17. With regard to your response to question 26 of the Staff's May 18, 1979 questions and the analysis of the rigging on the Turbine Building (a) Are the referenced AISC "allowables" the normal allowables?
(b) Provide the details of that analysis including loads, load combin-ations and corresponding acceptance criteria and justify all assump-tions.
(c) Did the analysis assume the failure of one chain fall and the resulting impact load on the girder?
- 18. With regard to your response to questien 32 of the Staff's May 18, 1979 questions, state and justify the loads, load combinations and correspond-ing acceptance criteria used in your analysis of the siding and siding connections on the Turbine Building.
- 19. With regard to your response to question 33 of the Staff's May 18, 1979 questions, state the criteria used to determine that the walls with the portions removed will be capable to withstand an SSE level greater than 0.259 and also an OBE greater than 0.08g and justify use of this criteria.
- 20. With regard to your response to question 42 of the Staff's May 18, 1979 questions (a) How did you estimate the increase in frequency for the 0.lg earthquake?
(b) On what basis did you determine that frequency shifts associated with modes other than the first mode are less than those of the first mode?
(c) Provide the details of your determination that "as the earthquake level increases from 0.10g to 0.15g, the stiffness reduction factors decrease gradually which will result in a gradual transition to the 0.159 response spectra."
- 21. Justify in detail your use of varying assumptions for the calculation of stiffness dcgradation and capacities versus the basic assumptions of the finite element model.
- 22. With regard to your response to question 6c of the Staff's May 18, 1979 questions, (a) Provide the basis for the calculation of limited shrinkage values.
(b) Provide the basis for the calculation of limited creep values.
(c) Provide the details of your aralysis to determine the adequacy of you'-
bolt tensioning sequence. What are the tensions in the various bolts and how will these tensions be monitored and checked?
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(d)
Provide the basis for the 500 temperature rise.
- 23. With regard to your response to question 6d of the Staff's May 18, 1979 questions, expand that response to include consideration of the transfer of shear from the surface of the wall into the overall wall itself.
24.
On page 2 of 3 of your response to quesr. ion 17 of the Staff's May 18, 1979 questions, your reference to the Newmark article regarding consideration of in-plane and transverse wall loadings is inappropriate and was taken out of context.
If the sentence preceeding this in the Newmark article is considered (namely, "It is reasonable to use the response spectrum approach even for multi-degree-of-freedom systems, to arrive separately at the responses in the individual directions, and then to combine the effects in general by taking the square root of the sums of the squares of the individual effects for stress or motion at a particular point in a particular direction for the various components of motion considered. It is considered conser-vative and simpler, and much more readily defined and calculated, to take the combined effects as 100 percent of the effects in one particular direction and 40 percent of the erfects correspond 1na to the two directions of motion at right angies to the princloal motion considered.") it is oovious that Newmark is addressing the combination of codirectional responses to each of the earthquake components. Therefore, consider an appropriate combination of transverse and in-plane loadings.
- 25. With regard to your response to question 31 of the Staff's May 18, 1979 questions, provide the loads, load combinations and corresponding acceptance criteria that were used to make your determination that the placement of reinforcing steel, the forms and the concrete will not significantly degrade the seismic capability of the Complex.
- 26. With regard to page 4 of 5 of your response to question 43 of the Staff's May 18, 1979 questions, confirm the accuracy of your moment resistance computation equation.
- 27. With regard to page 2 of 4 of your response to question 13 of the Staff's May 18, 1979 questions, provide sample calculations of your consideration of creep and shrinkage.
- 28. With regard to page 6 of 6 of your response to question 40 of the Staff's May 18, 1979 questions, (a)
Indicate the number of OBEs that are being considered at full cycles of stress.
(b)
Provide the basis for concluding that that number of OBEs will assure that the Complex can withstand many earthquakes at slightly below the OBE level.
. - 29. Provide details of the rail stop anchorages and your analyses to determine the adequacy of the rail stop.
Include justification that the assumed ductilities can be realized.
- 30. With regard to page 2 of 11 of your response to question 29 of the Staff's May 18, 1979 questions, extend your evaluations that confirm that all safety-related piping, cable trays and equipment attached to non-shear walls in the Complex retain support capabilities to safety-related piping, cable trays and equipment attached to shear walls in the Complex.
- 31. Justify your consideration of the full stiffness reduction factor rather than an " effective" stiffness reduction factor which is somewhat higher (stiffer) such as is used for soil in a soil / structure interaction analysis.
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ADDITIONAL SYSTEM-RELATED QUESTIONS FROM NRC STAFF 1.
With regard to page 2 of 5 of your response to. question-le of the Staff's July 20, 1979 questione, state the basis for your assertion that dropping plate 8 will only sever the cables in the top three penetrations and demonstrate that a dropped plate 8 will not cause other plates to tear lcose from the wall and sever additonal cables.
Provide the details of your analyses, your assumptions and justification therefor, including any analysis of the adequacy of the bolts holding the lower plates.
2.
In your responses to questions le and 5 of the Staff's July 20, 1979 questions, it is not clear that you will supply the three-inch plate or use an equivalent energy absorbring method to protect essential equipment and pipes below grade. Clarify that the three-inch plate or an equivalent energy absorbing method will be used and provide your analyses showing that the three-inch plate or the equivalent energy absorbing method be adequate to protect essential equipment and pipes below grade.
3.
What provisions e made with regard to lateral guidance of plate 8'to assure square impact on plates 5, 6 and 7 rather than plate 8 being cammed out by the chamfer on plates 5, 6 and 77 4.
Provid'e any additional justification available demonstrating either (a) that a plate drop cannot occur or (b) that upon dropping any plate and sustaining the damage therefrom, surviving essential cables and equipment are such that, along with operator actions taken within the required time periods, the plant s
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l cacbebroughttoandmaintainchincoldshutdownor,ifitis already in co M shutdown, it c6n be maintained in that status.
State explicitely all assumptions with rpgard to status of the plant, the accident being addressed, the time periods required for operator actions, and the spetific operator actions needed.
5.
With regard to page 5 of 5 of your response to question le of the Staff's July 20, 1979 questions, (a) Verify that severing all cables in the upper three penetrations through the Control Building wall will not disable diesel generator A and provide your bases.
(b) Would a plate drop severing all cables in the upper three penetrations disable any containment isolation valves such that valves would have to be manually opened to reach hot shutdown and remove decay heat?
6.
With. regard to your response to question le of the Staff's July 20, 1979 questions, should the term " steam pump control" be " steam dump control"?
7.
Describe the positive feed control on drills to be used for drilling for the plate installation and the manr:er in which it will prevent uncontrolled movement of the drill during drilling operations. Verify that the clearance between any drill hole and any safety-related cables or equipment is adequate to assure that the drill will not damage such cables or equipment.
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}A 8.
Describe ir, detail any areas where access to safety-related equipment may be affected by the modifications (e.g. removal of stairs, blocking doors), identify the safety-related equipment which is involved, and describe alternate mea'is of access to such equipment.
9.
Identify all areas where welding or cutting will be done pursuant to the modifications. Will welding or cutting be done in the Control Room, Cable Spreading Room or Electrical Auxiliary Room?
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