ML19257B834
| ML19257B834 | |
| Person / Time | |
|---|---|
| Site: | La Crosse File:Dairyland Power Cooperative icon.png |
| Issue date: | 12/20/1979 |
| From: | Linder F DAIRYLAND POWER COOPERATIVE |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| IEB-79-02, IEB-79-2, NUDOCS 8001210028 | |
| Download: ML19257B834 (5) | |
Text
-
T7C
.c IbitIItYLitNIb I'OWEIt COUI*EIt<tTIVE Ba Crone, 01'sconan i
54601 December 20, 1979 In reply, please refer to LAC-6704 DOCKET NO. 50-409 Mr. James G.
Keppler Regional Director U.
S. Nuclear Regulatory Commission Directorate of Regulatory Operations Region III 799 Roosevelt Road Glen Ellyn, Illinois 60137
SUBJECT:
DAIRYLAND POWER COOPERATIVE LA CROSSE BOILING WATER REACTOR (LACBWR)
PROVISIONAL OPERATING LICENSE NO. DPR-45 IE BULLETIN NO. 79-02, REVISION 2 - PIPE SUPPORT BASE PLATE DESIGNS USING CONCRETE EXPANSION ANCHOR BOLTS
Reference:
(1)
DPC Letter, Linder to Keppler, LAC-6483, dated August 23, 1979.
(2)
DPC Letter, Linder to Keppler, LAC-6602, dated October 24, 1979.
(3)
NRC Letter, Keppler to Linder, dated November 8, 1979, Enclosing IE Bulletin No. 79-02, Revision No. 2
Dear Mr. Keppler:
In response to the items of Reference 3, the following is submitted:
Item 1
......."A de scrip tion of the analytical model used to verifu that pipe support base plate flexibility is acocunted for in the calcul-ation of anchor bolt loads is to be submitted uith your response to the Bulletin."
DPC RESPONSE:
As stated in Reference 1, all pipe support base plates will be replaced.
The new base plates, with anchor bolts, were designed utilizing the method given in the AISC " Steel Construction Manual",
7th Edition on page 4-80.
The calculation included base plate flexr ibility factors.
1773 020 DEC 261978 8 00121 o c3r);2r
Mr. James G.
Keppler, Regional Director LAC-6704 U.
S.
Nuclear Regulatory Commission December 20, 1979 Item 2 "Ve rify that the concrete expansion anchor bolts have the follouing minimum factor of safe ty be tueen the bolt design load and the ultimate capacity.....etc."
DPC RESPONSE:
The new pipe support base plates will utilize wedge type concrete anchors which, when installed, will have a safety factor greater than four.
Item 3
" Describe the design requirements, if applicable, for anchor bolts to uithstand cyclic loads....."
DPC RESPONSE:
As all the base plates pipe supports utilize a constant support hanger, cyclic loads are not applicable.
Item 4
" Verify.... that design requiremen ts have been met for each anchor bolt in the follouing areas:
(a)
Cyclic loads....and shell type.
(b)
Specified design sise and type is correctly installed. "
DPC RESPONSE:
(a)
See item 3 above, and no shell types are to be used.
(b)
This will be accomplished upon installation.
Item 5
" Determine the emtent that c pansion bolts vere used in concrete block (masonry) valls....."
DPC RESPONSE:
No pipe supports are used in concrete block walls.
1773 021 Mr. James G. Keppler, Regional Director LAC-6704 U.
S. Nuc'aar Regulatory Commission December 20, 1979 Item 6
" Determine the extent that pipe supports with expansion bolts used structural steel shapes instead of base plates. "
DPC RESPONSE:
The systems within the scope of this Bulletin (as explained in Reference 1) have been reviewed for structural steel shape hangers that use expansion anchor bolts.
Item 6. a
" Provide a list...."
No. of Type of Line System Supports Anchor Bolt Size Accessible HPCS 6
Shell 3
Yes Suction HPCS 2
Shell 2
Yes Dis-charge Boron 3
Shell 2h Yes Inject Item 6.b
" Provide a detailed evaluation of the adequacy of the anchor bolt design and installation....."
DPC RESPONSE:
Based on visual examination of all the hangers in the table above, we believe that the three safety related systems are capable of continued safe operation because of the following:
a.
All of the structures were in good physical shape, i.e.,
no deformations, no expansion bolts were loose, no hanger pulled away from the wall.
b.
The lines involved are all of a small size. 1773 022
'fr. James G.
Keppler, Regional Director LAC-6704 U.
S. Nuclear Regulatory Commission December 20, 1979 c.
Other hangers not anchored by expansion bolts are used on the lines.
d.
The loads on the hangers are small.
e.
All of the above lines contain static cold water during normal plant operation.
Item 6. c
" Describe your plans and sche dules for any further action..... "
DPC RESEONSE:
The hangers listed in the table above are to be redesigned and in-stalled with wedge type expansion anchors.
The installation can be accomplished in conjunction with the base plate hanger replacement, as indicated in Reference 2.
Item 7
"..... Provide a schedule that details the completion dates for IE Bulletin No. 79-02, Revision 2, items 1,
2, and 4."
DPC RESPONSE:
The designs for the base plates pipe supports has been completed and they are in the process of fabrication.
See the response to Item 2 above.
No documentation of existing hanger installations exist, therefore DPC has opted to replace all expansion anchor bolts.
(See response to Item 4 above.
Item 8
" Maintain documentation.....etc."
DPC RESPONSE:
LACBWR will retain all records associated with the design and installation of the pipe support hangers, required by the subject Bulletin. 1773 023
epp er, Regiona Director LAC-04 r.
ames U.
S. Nuclear Regulatory Commission December 20, 1979 If there are any questions regarding this submittal, please contact us.
Very truly yours, DAIRYLAND POWER COOPERATIVE Y
AAAGlG W
J Frank Linder, General Manager FL: HAT:af cc:
U.
S. Nuclear Regulatory Commission Office of Inspection and Enforcement Division of Reactor Operations Inspection Washington, D.
C.
20555
, 1773 024