ML17083C048
| ML17083C048 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 10/05/1987 |
| From: | Trammell C Office of Nuclear Reactor Regulation |
| To: | Shiffer J PACIFIC GAS & ELECTRIC CO. |
| References | |
| TAC-65292, TAC-65293, NUDOCS 8710150098 | |
| Download: ML17083C048 (16) | |
Text
October 5, 1987 Docket Nos.:
50-275 and 50-323 Mr. J.
D. Shiffer, Vice President Nuclear Power Generation c/o Nuclear Power Generation, Licensing Pacific Gas and Electric Company 77 Beale Street, Room 1451 San Francisco, California 94106
Dear Mr. Shiffer:
DISTRIBUTION
,:~ j NRC 5 LPDRs CTrammell GHolahan JLee OGC-Bethesda PDV Plant File EJordan JPartlow ACRS (10)
RBrady
SUBJECT:
ALLEGATIONS OF CONSTRUCTION DEFICIENCIES - DIABLO CANYON (TAC NOS.
65292 AND 65293)
ALLEGATION NO. NRR-87-A-0008 The staff has received allegations, as explained in the enclosure, pertaining to Diablo Canyon Nuclear, Power Plant, Unit Nos.
1 and 2.
You are requested to review the allegations and conduct appropriate inspections and/or evaluations as necessary.
Substantiated allegations may warrant corrective action.
We request that you inform us, within 30 days of receipt of this letter, of your initial assess-ment of these allegations and the actions you intend to take.
We intend to inspect related activities and audit the records of your completed actions after receiving your written response to the seven questions identified in the enclosure.
The reporting and/or recordkeeping requirements contained in this letter effect fewer than ten respondents; therefore, OMB clearance is not required under Pub. L.96-511.
Please contact us should you have any questions regarding this matter.
87iol50098 871000275 PDR ADQCN, 050 PDR P
Sincerely, Original signed by Terence L. Chan for Charles M. Trammell, Project Manager Project Directorate V
Division of Reactor Projects - III, IV, V and Special Projects
Enclosure:
Evaluation of Allegations cc w/enclosure:
See next page DRSP/PD5 CTrammell:
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D. Shiffer Pacific,Gas and Electric Company Diablo Canyon CC:
Richard F. Locke, Esq.
Pacific Gas 5 Electric Company Post Office Box 7442 San Francisco, California 94120 Janice E. Kerr, Esq.
California Public Utilities Commission 350 HcAllister Street San Francisco, California 94102 Ms. Sandra A. Silver 660 Granite Creek Road Santa Cruz, California 95065 Mr. W. C. Gangloff Westinghouse Electric Corporation P. 0.
Box 355 Pittsburgh, Pennsylvania 15230 Managing Editor San Luis Obispo County Telegram Tr'ibune 1321 Johnson Avenue P. 0.
Box 112 San Luis Obispo, California 93406 Mr. Leland M. Gustafson, Hanager Federal Relations Pacific Gas and Electric Company 1726 M Street, N.
W.
Washington, DC 20036-4502 Dian H. Grueneich, Esq.
Edwin F. Lowry, Esq.
Grueneich 5 Lowry 380 Hayes Street Suite 4
San Francisco, California 94102 NRC Resident 1nspector Diablo Canyon Nuclear Power Plant c/o U.S. Nuclear Regulatory Commission P. 0.
Box 369 Avila Beach, California 93424 Hr. Dick Blakenburg Editor 8 Co-Publisher South County Publishing Company P. 0.
Box 460 Arroyo Grande, California 93420 Bruce Norton, Esq.
c/o Richard F. Locke, Esq.
Pacific Gas and Electric Company Post Office Box 7442 San Francisco, California 94120 r-Dr. R. B. Ferguson Sierra Club - Santa Lucia Chapter Rocky Canyon Star Route
- Creston, California 93432 Chairman San Luis Obispo County Board of Supervisors Room 220 County Courthouse Annex San Luis Obispo, California 93401 Director Energy Facilities Siting Division Energy Resources Conservation and
~
Development Commission 1516 9th Street Sacramento, California 95814 h1s. Jacquelyn Wheeler 2455 Leona Street San Luis Obispo, California 93400
Pacific Gas 8 Electric Company 2 -
Diablo Canyon cc:
Ys. Laurie McDermott, Coordinator Consumers Organized for Deferse of Environmental Safety 731 Pacific Street, Suite 42 Sar Luis Obispo, California 93401 Yr. Joseph
- 0. Ward, Chief Radiological Health Branch State Department of Health Services 714 P Street, Office Building P8 Sacramento, Ca 1 ifornia 95814 Regional Administrator, Region V
U.S. Nuclear Regulatory Correission 1450 Maria Lane Suite 210 Walnut Creek, California 94596 Yis. Nancy Culver 192 Luneta Street San Luis Obispo, California 93401 President California Public Utilities Commission California State Building 350 McAllister Street San Francisco, California 94102 Michael M. Strumwasser, Esq.
Special Assistant Attorney General State of California Department of Justice 3580 Wi lshire Boulevard, Room 800 Los Angeles, California 90010
EVALUATION OF ALLEGATIONS ON HILTI KWIK BOLTS INTRODUCTION Allegations on Hilti Kwik bolts at Diablo Canyon and technical bases for the allegations were attached to a letter addressed to C. Trammell of NRC dated July 24, 1987.
The allegations can be summarized as two technical, issues.
One is excessive embedment
- length, and the other involves anchor spacing problems.
The two technical issues will be discussed and evaluated on their merits.
The staff conclusions will be stated.
EVALUATION With respect to the excessive embedment length issue, the specific bolts cit~d by the alleger were located in Area:
GE, Elevation: 85, Column/Line:
T 5 12 Support 55S/41A, on Revision 4 of Drawing $049258, Line 1-K-106-18 C, Sys.
0'14.
The alleger reported that a cone-shaped section of concrete popped out of the ceiling directly under three of the Kwik bolts as they were being set or torqued.
He also reported that these bolts were designed to have a minimum embedment length of 10$ inches in a 12-inch thick concrete floor.
Thus, the embedment length of the bolts is equivalent to 885 of the floor slab thickness.
The alleger questioned the design adequacy of such a long embedment length of bolts and doubted that the necessary repairs had been made properly.
The staff has found from the Hilti Anchoring manual, published by the Kwik bolt manufacturer, that the maximum embedment length of Kwik bolts should be limited to 77% of the floor slab thickness of which the bolt is to be anchored.
Since the actual embedment length of bolts designed and used by the licensee may be embedded more deeply into concrete slabs than allowed by the manufacturer, the alleger's concerns may be valid.
Whether the strength of the floor slab and the concrete holding the bolts have been reduced as the result of the concrete cones popped out of the ceiling need to be evaluated by the licensee.
The licensee also needs to evaluate whether the phenomenon of concrete cones popped out from the ceiling was only an isolated incident or a generic one.
With respect to the anchor spacing issue, it was reported that while drilling bolt holes for hanger 44-79R in the intake structure, the drill encountered the back end of an abandoned anchor bolt for hanger 44-78R.
The alleger questioned whethe~ the bolts on both sides of a floor slab had ever been designed for the two adjacent bolts located and pulled in opposite directions, and detailed on the drawings for proper spacing.
The alleger believed that the concrete between two adjacent bolts would be stressed less favorably when the bolts were located and pulled in opposite directions of a floor than the case in which the bolts were located on and pulled from the same direction.
The alleger ques-tioned how the safe spacing between bolts was established by the licensee when the adjacent bolts were located and pulled in opposite directions.
Sufficient spacing between bolts is necessary for the development of the strength of'a
V' bolt.
Insufficiert spacing between bolts will reduce the strength of a bolt to be developed due to the insufficient concrete strength of holding a bolt, and may cause concrete cracking between the bolts.
Therefore, the licensee needs to demonstrate that the spacino of the bolts was designed properly and maintained in the field as designeo.
CONCLUSIONS AND RE UIRED LICENSEE ACTIONS Based on the above evaluation, the staff has concluded that the two technical issues raised by the alleger have merit and need to be addressed by the licensee.
In addressing the two issues, the licensee is requested to provide answers to the following questions:
1.
What are the technical bases of using a minimum bolt embedment length of 104 inches in a 12-inch thick concrete floor or wall?
2.
What kind of repairs have been made to the ceiling where concrete cones had been popped out as a result of torquing the bolts?
3.
Mere the three bolts of which concrete cones had been popped out directly under them accepted?
If so, on what bases?
4.
How were the spacings of adjacent bolts in opposite directions of a floor or wall at Diablo Canyon established and what were the techni-cal bases?
5.
Were the bolts, which were used to anchor safety-related piping or equipment, detailed on the drawing for installation?
If yes, what kind of gA/(jC procedures were used to ensure proper locations and spacings of bolts?
If no, why not?
6.
Were the deficiences identified by the alleger a few isolated cases or more generic and applicable to other parts of the plant?
Provide the basis for your answer to this generic implication related concern.
7.
Provide specific dispositions to be implemented for the resolution of the allegations.
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October 5,
1987
~DISTRIBUTION
~Docket
'- JLee (2)
DOCKET'O(S).
50-275/3~>
Mr. J. D. Shiffer, Vice President
,'uclear Power Generation c/o Nuclear Power Generation, Licen'sing Pacific Gas and Electric Company 77 Beale Street, Room 1451 San Prancisco, CA 94106
SUBJECT:
PACIFIC GAS AND ELECTRIC COMPANY DXABLO CANYON NUCLEAR PO!KR PLANT The following documents concerning:our review of the subject facility are transmitted for your information.
lr t
Notice of Receipt of Application dated Draft/Final Environmental Statement,'ated Notice of Availability of Draft/final Environmental Statement, dated Safety Evaluation Report, or Supplement No.
dated Environmental Assessment and Finding of No Significant Impact, dated Notice of Consideration of Issuance of Facility Operating License or Amendment to Facility Operating "License, dated Qg Hi-Weekly Notice; Applications and Amendments to Operating Licenses Involving No if'I*d C
d i
.d d~[
(II Exemption, dated Construction Permit No.
CPPR-
, Amendment No.
dated Facility Operating License No. ',
Amendment No.
dated Order Extending Construction Completion Date, dated Monthly Operating Report for, transmitted by letter dated Annual/Semi-Annual Report-transmitted by, letter dated Encl osures:
As stated Office of Nuclear Reactor Regulation cc:
See next page OFFICE)
SURNAME/
OATEN NRC FORM 3I8 IIOIBOINRCM 0240 OFFtCIAL RECORD COPY
~ ~ ~ ~
~
~
Hr. J.
D. Shiffer Pacific Gas and Electric Company Diablo Canyon CC:
Richard F. Locke, Esq.
Pacific Gas 8 Electric Company Post Office'ox 7442 San Francisco, California 94120 Janice E. Kerr, Esq.
California Public Utilities Commission 350 McAllister Street San Francisco, California 94102 Ms. Sandra A. Silver 660 Granite Creek Road Santa Cruz, California 95065 Hr.
W. C. Gangloff Westinghouse Electric Corporation P. 0.
Box 355 Pittsburgh, Pennsylvania 15230 Managing Editor San Luis Obispo County Telegram Tribune 1321 Johnson Avenue P. 0.
Box 112 San Luis Obispo, California 93406 Mr. Leland M. Gustafson, Manager Federal Relations Pacific Gas and Electric Company 1726 M Street, N.
W.
Washington, DC 20036-4502 Dian M. Grueneich Marcia Preston Law Office of Dian M. Grueneich 380 Hayes Street, Suite 4
San Francisco, California 94102 NRC Resident Inspector Diablo Canyon Nuclear Power Plant c/o U.S. Nuclear Regulatory Commission P. O.,Box 369 Avila Beach, California 93424 Mr. Dick Blakenburg Editor 5 Co-Publisher South County Publishing Company P. 0.
Box 460 Arroyo Grande, California 93420 Bruce Norton, Esq.
c/o Richard F. Locke, Esq.
Pacific Gas and Electric Company Post Office Box 7442 San Franci sco, California 94120 Dr. R. B. Fer guson Sierra Club - Santa Lucia Chapte~
Rocky Canyon Star Route Creston, California 93432 Chairman
.San Luis Obispo County Board of Supervisors Room 220 County Courthouse Annex San Luis Obispo, California 93401 Director Energy Facilities Siting Division Energy Resources Conservation and Development Commission 1516 9th Street Sacramento, California 95814 Ms. Jacquelyn Wheeler 2455 Leona Street San Luis Obispo, California 93400
Pacific Gas 5 Electric Company Diablo Canyon CC:
Ms. Laurie McDermott, Coordinator Consumers Organized for Defense of Environmental Safety 731 Pacific Street, Suite 42 San Luis Obispo, California 93401 Mr. Joseph
- 0. Ward, Chief Radiological Health Branch State Department of Health Services 714 P Street, Office Building à Sacramento, Cali for nia 95814 Ms. Nancy Culver 192 Luneta Street San Luis Obispo, California 93401 President California Public Utilities Commission California State Building 350 McAllister Street San Francisco, California 94102 Regional Administrator, Region V
U.S. Nuclear Regulatory Commission 1450 Maria Lane Suite 210 Walnut Creek, California 94596 Michael M. Strumwasser, Esq.
Special Assistant Attorney General State of California Department of Justice 3580 Wilshire Boulevard, Room 800 Los Angeles, California 90010