ML18054A619
| ML18054A619 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 03/30/1989 |
| From: | Frisch R CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| IEB-80-11, TAC-42915, NUDOCS 8904100087 | |
| Download: ML18054A619 (10) | |
Text
consumers Power POWERINli MICHlliAN*s PROGRESS General Offices: 1945 West Parnall Road, Jackson, Ml 49201 * (517) 788-0550 March 30, 1989 Nuclear Regulatory Commission Document Control Desk Washington, DC 20555 DOCKET 50-255 - LICENSE DPR PALISADES PLANT -
RESPONSE TO NRC REQUEST FOR ADDITIONAL INFORMATION ON IE BULLETIN 80-11, "MASONRY WALLS" (TAC NO 42915)
By letter dated April 15, 1988, the NRC requested additional information regarding Consumers Power Company's responses.to IE Bulletin 80-11, "Masonry Walls".
Our letter dated July 20, 1988 identified work had begun on responding to the request, however, much of the remaining effort hinged on obtaining the original calculational packages from the architect/engineer.
These packages were not received until January, 1989, therefore, the attached response is considered partial at this time.
As indicated in the attachment, five walls require further evaluation or justification.
Two walls (C-107-12 and C-108-12) require further evaluation attributable to finding problems in previous calculations as a result of additional reviews conducted for this response.
Three walls (C-107-05, C-107-14 and C-321-01) require jtistification of arching action for qualification.
Consumers Power Company intends to enlist the services of a vendor to further justify this qualification technique.
The additional evaluation and justification will be completed and the results submitted for NRC review by October 1, 1989.
~rl(:zt~L Senior Licensing Analyst CC Administrator, Region III, NRC NRG Resident Inspector - Palisades Attachment 89041 (100:37 PDR ADOCI<
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OC0389-0105-NL04 89(13:30 05000255 PDC A CMS ENE'RGY COMPANY ff,1/
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OC0389-0105-NL04 ATTACHMENT Consume.rs Power Company Palisades Plant Docket 50-255 RESPONSE TO NRC REQUEST FOR ADDITIONAL INFORMATION ON IE BULLETIN 80-11, "MASONRY WALLS" March 30, 1989 8 Pages
1 QUESTION 1 With reference to the reinforcement in masonry walls, the ACI 531-79 Code (Ref. 1) specifies that the minimuIIl' area of reinforcement in a wall in either direction, vertical or horizontal, shall be 0.0007 (0.07%) times the gross cross-sectional area of the wall and that the minimum total area of steel, vertical and horizontal, shall not be less than 0.002 (0.2%) times the gross cross-sectional area.
In view of this, clarify whether the reinforced walls at this plant *meet the above criteria.*
RESPONSE
Thirteen walls relied on reinforcement in their qualification analysis.
Of the thirteen walls, three walls comply with the definition of, "reinforced masonry",
arbitrarily defined in Section 11.3.2.2 of ACI 531-79.
The remaining ten walls are identified below:
Wall No. C-104-06 C-104-11 C-104-12 C-107-12 C-107-16 C-107-17 C-108-02 C-108-05 C-108-12 C-109-07 All walls met the requirement of 0.07% reinforcement in the vertical direction.
Four walls C-104-06, C-104-11, C-107-16 and C-109-07 relied only on the vertical reinforcement in an analysis using a vertical element to qualify them.
Four of the remaining six walls C-104-12, C-107-17, C-108-02, and C-108-05 do not meet the requirements of 0.07% horizontal reinforcement or the requirement of 0.2%
combined area of horizontal and vertical reinforcement.
Although these walls do not meet these requirements, their respective analyses show they have sufficient strength to resist the imposed loads.
The remaining two walls C-107-12 and C-108-12 require further evaluation (see response to Question 2).
OC0389-0105-NL04
2 QUESTION 2 If the joint reinforcement is used to resist tension in a vertically reinforced wall, it should follow the working stress design method which limits its allowable to 30 ksi.
Please clarify whether this criterion has been satisfied.
If this criterion is not satisfied, identify all affected walls along with the calculated stress value for each wall.
RESPONSE
Six walls relied on joint reinforcement in combination with vertical reinforcement to resist the imposed out-of-plane loads.
The six walls are:
C-104-12 C-107-12 C-107-17 C-108-02 C-108-05 C-108-12 The working stress design method was utilized in the analysis of these walls.
The allowable joint reinforcement stress of 30 ksi identified in Section 10.2.1.2 of ACI 531-79 was used for normal loadings.
For extreme loads such as SSE, the allowable working stress of 30 ksi was factored by 1.67 which is within the guidelines of Standard Review Plan 3.8.4 Appendix A.
Walls C-104-12, C-107-17, C-108-02, and C-108-05 satisfy the allowable joint reinforcement as defined above.
The joint reinforcement in walls C-107-12 and C-108-12 appears to be overstressed based on the above criteria. This condition will be evaluated further and the results submitted for NRC review.
OC0389-0105-NL04
3 QUESTION 3 Indicate any wall that has only joint reinforcement (horizontal reinforcement),
no vertical reinforcement, and may have been qualified using the tensile resistance of the joint reinforcement.
(See enclosure 2).
RESPONSE
No masonry walls included in Palisades IE Bulletin No. 80-11 evaluation are in this category.
OC0389-0105-NL04
4 QUESTION 4 With regard to the arching action technique, the use of the arching action theory to qualify unreinforced masonry walls is not proven.
(See enclosure 3).
Please provide additional justification for not modifying walls 107.5, 105:14, and 321.1.
RESPONSE
The reference to wall 105.14 in this question appears to be a typographical error.
The correct reference should be to wall C-107-14.
Consumers Power Company intends to enlist the services of Computech Engineering Services, Inc.,
Berkeley, CA for the purpose of justifying arching action to qualify walls C-107-05, C-107-14, and C-321-01.
Results will be submitted for NRG review in a follow up submittal.
OC0389-0105-NL04
5 QUESTION 5 In Response No. 11 of Reference 3, a sample calculation was provided for beam
~race modification for wall C-104.5 in which the modified wall was analyzed as a horizontal beam strip.
However, drawing FSK-C-104.5 (Q) (1) shows that the two vertical sides of the wall are free.
Since the vertical sides are free, please provide justifications for the horizontal beam strip assumption.
RESPONSE
The analysis models wall C-104-05 as a horizontal strip 1 ft. in width and 4 ft long supported by a single vertical member located 20 in. from the west end of the wall. The ends of the wall are not considered to be supported in the analysis.
The shear and tensile allowable stresses of the masonry are shown not to be exceeded, therefore, the wall is capable of resisting the imposed loads.
OC0389-0105-NL04
QUESTION 6 In Response No. 4 of Reference 3, a total of four walls (C-107.10, C-107.28, C-107.31, C-108.11) were identified to be removed.
Please provide the status of these walls.
RESPONSE
Walls C-107-10, C-107-28, C-107-31,. and C-108-11 have been removed.
OC0389-0105-NL04 6
7 QUESTION 7 Reference 3 indicated that plate analysis was used to qualify a number of walls.
Please explain the analytical procedures used in the post-cracked state of the wall (i.e., cracks along the vertical and horizontal direction).
RESPONSE
Plate analysis was used to qualify *twenty-six walls.
Of the twenty-six walls, seventeen walls did not exceed the allowable tensile stresses in the masonry and were qualified using uncracked section properties.
The remaining nine walls used the cracked section properties of the reinforced masonry for qualification.
OC0389-0105-NL04
8 QUESTION 8 In Response No. 9 of Reference 3, wall 303.9 was identified as unqualified under tornado missile impact.
However, it was stated that no modification was needed.
Please provide justification for not modifying this wall (i.e.,
details of the wall with surrounding structures, quantitative results supporting your conclusion).
RESPONSE
Per Consumers Power Company response to NRC dated November 8, 1982 and titled, "PALISADES PLANT -
RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING IE BULLETIN 80-11, MASONRY WALLS", Wall C-303-09 is a 6' x 6' x 2' thick solid block wall, serving as a blackout in a major structural wall separating the auxiliary and service buildings.
The block wall is considered an exterior wall in that the surrounding service building is not designed for tornados.
There is no safety-related equipment in proximity to the block wall.
The service building side of the wall is almost entirely covered by a massive junction box containing security circuitry.
Although the circuitry is not safety related, continuous surveillance of the plant area would be required as the security equipment is handled during any anticipated modification.
The auxiliary building side of the wall bounds the elevation 602'-0" pipeway where the radiation field is very high.
The block wall could conceivably be modified by replacing it with reinforced concrete.
This modification would expose the service building to radiation fields from the pipeway during construction.
An alternative modification would be to install a thick steel plate over the service building side that would provide a tornado protection already provided to a limited extent by the junction box and service building.
In view of ALARA considerations and in consideration of the fact that the service building and junction box do indeed provide some tornado protection, a modification would provide only a marginal increase in safety.
OC0389-0105-NL04