ML071360351
| ML071360351 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 05/14/2007 |
| From: | Duke Power Co |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| Download: ML071360351 (3) | |
Text
Oconee Nuclear Station FRP RAI Issues Item #
NRC Issue
-Duke Comments Resolution of Item1 FRP 1 to the letter listed 53 walls that 0
This appears to be an introductory, summary 0
Simple beam and plate theory will be currently planned to be strengthened using FRP.
statement of the content of Enclosure 3 to used to calculate masonry wall The walls include single-wythe 8" hollow-core Duke's response to the RAI.
stresses.
concrete block and double-wythe 4" solid concrete brick. The aspect ratios (heightwidth)
Duke presented the proposed analytical 0
FRP will be substituted for steel of walls vary from 0.6 to 2.9. The edge methods and detailed equations in Enclosures reinforcing, when necessary.
conditions of walls are mortat-joint edges at top, 4 and 5 to its response to the RAI. Sample The various configurations from the bottom, and both sides, and mortat-joint edges at calculations using these equations are l
of valls w
ion be the top, bottom, and one side.
presented in Enclosures 6 and 7 to its list of 53 walls will be bounded response to the RAI. Test data to substantiate (meets code allowables) by one of the We made very clear to the licensee in our the analytical methods is presented in two design methodologies proposed previous meetings that the licensee needs to Enclosures 8 and 9. The test data is evaluated in the RAI response. These present their specific methods (equations) for using the analytical methods and detailed methodologies are supported by test using FRP to strengthening the particular type of equations of Enclosures 4 and 5 to data.
masonary walls and submit test data that can demonstrate their validity and conservative 0
If a wall does not meet one of these substantiate the methods (equations) that they results.
two methodologies, the wall(s) will propose to use. However, the licensee failed be physically modified to meet the again to response to this request.
criteria.
0 Test coupons and pull tests will verify FRP strength and adhesion.
FRP 2 Instead, the licensee responded that it would use This statement appears to indicate a 0
The more conservative reduction ACI 440.2R-02 or FRP system manufacturer's misunderstanding of the information factors for the FRP system method, as documented on page 9 of Enclosure presented in Enclosure 5 to Duke's response manufacturer or ACI 440.2 will be
- 5.
to the RAI. On page 9 of Enclosure 5, Duke used.
stated that it would use the working stress design method for reinforced masonry to deThesafe m hat De n
to design the FRP flexural reinforcement. To demonstrate should be a factor of 3 supplement these equations, Duke also stated that it would use the environmental and strength reduction factors and most restrictive strain limitations (i.e., allowable stress) for the FRP-from ACI 440.2 or the FRP system manufacturer.
Duke will provide hardcopies of the RAI response (with all enclosures) to all present at the May 14th meeting.
Page 1 of 3 DRAFT DOCUMENT - FOR DISCUSSION PURPOSES ONLY
Oconee Nuclear Station FRP RAI Issues Item #
NRC Issue.
Duke Comments Resolution of Item1 Based on the types of masonry construction tabulated in Enclosure 3 to Duke's response to the RAI, only two fundamental wall types exist: simply-supported one-way span and simply-supported plate (4 sides). Additional test data would be representative of these two types of masonry construction.
FRP 3 The licensee agreed with the staff in our Duke presented test data to substantiate the The parameters of concern include (but previous meetings that ACI 440.2R-02 had not proposed analytical methods in Enclosures 8 and 9 may not be limited to) FRP manufacturer, been reviewed and adopted by the ACI code, to its response to the RAI. The parameters, extent, wall boundary conditions, masonry in-fill and the staff did not accept it as an accepted and format of any additional test data require material, and wall aspect ratios (2-way method. However, the staff stated that it would clarification.
action).
accept the licensee's methods if they can be substantiated by, or were derived from, test data.
During our last meeting, the licensee referred the method and substantiation as a box and stated that only walls falling within the box could use the method.
FRP 4 During our last meeting, the licensee did not See Response to FRP #2.
Agreed.
know how many types of walls they had and therefore did not know how many boxes they would have. Now, they know the types of walls they plan to strengthen using FRP, but provided no single box. For an example, based on available test data, a box can be established for walls of single-wythe 8" hollow-core concrete block with mortat-joint edges at top, bottom, and both sides for aspect ratios between x and y and another box can be established for walls of double-wythe 4" solid concrete brick with mortat-joint edges at top, bottom, and one side for aspect ratios between x and y. The licensee needs to establish as many boxes as required to cover the 53 walls.
Page 2 of 3 DRAFT DOCUMENT - FOR DISCUSSION PURPOSES ONLY
Oconee Nuclear Station FRP RAI Issues Item NRC Issue Duke Comments:-
Resolution of Item1 FRP 5 I have also reviewed the FRP system Duke does not understand the intent of this Only using their design material for manufacturer's (FYFE CO.) design manual, and statement.
material properties - no further action it has no reference to Oconee's walls.
required.
FRP 6 It is the licensee's responsibility to provide the See response to FRP 2.
Agreed.
methods (equations) for using FRP and present test data to substantiate the adequacy of the methods for Oconee walls.
FRP 7 The NRC stated that there is an engineering If this statement refers to the applicability of Test data will be used to substantiate the (Conf.
mechanics problem with the way Duke is plate theory in the computation of masonry design approach.
attempting to equate the test data with the given wall internal forces/moments for the simply-call note) methodology.
supported plate (4 sides) assumption, Duke cites the position of ACI 530, Masonry Standards Joint Committee, on the matter as reflected in the Commentary on ACI 530-05, Section 1.1.3:
"For allowable stress design, linear elastic materials following Hooke's Law are assumed, that is, deformations (strains) are linearly proportional to the loads (stresses).
All materials are assumed to be homogeneous and isotropic, and sections that are plane before bending remain plane after bending. These assumptions are adequate within the low range of working stresses under consideration."
FRP 8 Clarification of long-term FRP surveillance Described in original LAR.
No further action.
requirements?
FRP 9 Anchorage needs to be considered in design, Not fully addressed in LAR.
Agreed.
e.g., FRP to wall & end-connection details -
adhesion to wall only or to wall/frame?
Page 3 of 3 DRAFT DOCUMENT - FOR DISCUSSION PURPOSES ONLY