ML20010F638
| ML20010F638 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 08/11/1981 |
| From: | Stolz J Office of Nuclear Reactor Regulation |
| To: | Mattimoe J SACRAMENTO MUNICIPAL UTILITY DISTRICT |
| References | |
| TAC-46519, NUDOCS 8109110044 | |
| Download: ML20010F638 (6) | |
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NRC PDR AUGUST 1 1 1931 UKu#4 Rdg L PDR e
DEisenhut TERA 0 ELD NSIC Docket No. 50-312 IE-3 AE0D ACRS-10 JStolz MPadovan Mr. J. J. Mattimoe RIngram Assistant General Manager and Gray File Chief Engineer EBlackwood Sacramento Municipal Utility H0rr. stein f
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h.1 6201 S Street P. O. Box 15830 r
Sacramento, California 95813 24 AUG 171981> 7 i 8
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Dear Mr. Mattimoe:
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SUBJECT:
TOWER CRANE USE g
Reference:
5 MUD letter to NRC dated June 12, 1981 Your above referenced letter requested our review of your tower crane installation at Rancho Seco. As previously discussed with members of your staff, additional information is required before we can find your installation to be acceptable.
Enclosed are our coments and a request for information. We are aware that the probability of a high wind speed tornado occurring at the Rancho Seco site is very remote, However, some type of compensating measures would be appropriate once you are notified of a tornado
" watch." Our tnoughts on this matter can be found in the enclosure.
If you have any questions, contact ycur NRC Project Manager.
Sincerely.
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80RIGI:3L SIC:ED BY JCIC F. STOLTZ' John F. Stolz, Chief Operating Reactors Branch f4 Division of Licensing Enclosurc:
l Request for Addit.ional Information cc w/ enclosure:
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4 Sacramer.to Municipal Utility Rancho Seco, Docket No. 50-312 District ccw/ enclosure (s):
David S. Kaplan, Secretary ai.d Christopher Ellis,on, Esq.
General Counsel Dian Grueuich, Esq.
6201 S Street California Energy Commission P. O. Box 15830 1111 Howe Avenue Sacramento, California 95813 Sacramento, California 95825 Sacramento County Ms. Eleanor Schwartz Board of Supervisors California State Office.
827 7th Street, Room 424 600 Pennsylvania Avenue, S.E., Rm. 201 Sacramento, California 95814 Washington, C. C.
20003 Business and Municipal Department Docketing and Service Section Sacramento City-County Library Office of the Secretary 828 I Street U.S. Nuclear Regulatory Comaission Sacramento, California 95814 Washington, D. C.
20555 Res.ident.'asocetor/ Rancho Seco l
c/o U. S. N.'R. C.
i 14410 Twin Cities Road Herald, CA 95633 Dr. Richard F. Cole Atonic Safety S Licedng Board Panel U.S. Nuclear Regulatcry comission Washington, D. C.
20555 Regional Radiation Eepresentative EPA Reofon IX Mr. Frederick J. Shon 215 Fremont Street Atomic Safety and Licensing Board San Francisco, California 94111 Panel U.S. Nuclear Regulatory Commission Mr. Robert B. Borsum Washington, D. C.
20555 Babcock & Wilcox i
Nuclear Power Generation Division Elizabeth S. Bowers, Esq.
Suite 420, 7735 Old Georgetown Road Chairman, Atomic Safety and l
Bethesda, Maryland 20014 Licensing Board Panel U.S. Nuclear Regulatory Conmission Thomas Baxter, Esq.
Washington, D. C.
20555 Shaw, Pittman, Potts & Trowbridge 1800 M Street, N.W.
Mr. Michael R. Eaton Washington, D. C.
20036 Energy Issues Coordinator Sierra Club Legislative Office Herbert H. Brown, Esq.
1107 9th Street, Room 1020 Lawrence Coe Lanpher, Esq.
Sacramento, California 95814 Hill, Christopher and Phillips, P.C.
1900 M Street, N.W.
Atomic Safety and Licensing Board Washington, D. C.
20036 Panel U.S. Nuclear Regulatory Commission Helen Hubbe.rd Washington, D. C.
20555 P. O. Box 63 St.1ol, California 94586
s Sacramento Municipal Utility
- District Atomic Safety and Licensing Appeal Board Panel U.S. Nuclear Regulatory Commission Washington, D. C.
20555 Alan S. Rosenthal, Chairman Atomic Safety and Licensing Appeal Board U. S. Nuclear Regulatory Commission Washington, D. C.
20555 Dr. John H. Buck Atonic Safety and Licensing Appeal Board U. S. Nuclear Regulatory Commission Washington, D. C.
20555 Christine N. Kohl Atomic Safety and Licensing Appeal Board U. S. Nuclear Regulatory Commission Washington, D. C.
20555 California Department of Health ATTN: Chief. Environmental Radiation Control Unit Radiological Health Section 714 P Street, Room 498 Sacramento, California 95814
s to 12r. dtd. 8/11/81 4
ENCLOSURE,,
TOWER CRANE USE AT RANCHO SECO (DOCKET NO. 50-312)
STRUCTURAL ENGINEERING BRANCH A.
EVALUATION OF THE LICENSEE'S SUBMITTAL 1.
The UBC* formula has been used to calculate the natural period of the tower crane. However, the UBC formula is generally applicable to building structures. For specialized structure like the tower crane structure, the applicability of this formula is not verified.
In additicn, this formula is an approximation for first lateral mode of vibration. The crane structure is probably much stiffer in vertical direction and the natural period in this direction will be considerably different. Ef fects of higher modes of vibration are ignored.
2.
The FISAR (5B, pg. 5B-7, items 3b & e) damping values are tied to i
the stress levels. For primarily welded structures, unless it can be shown that general stress levels a~e at or near yield level, the 5%
damping value used needs more justification.
3.
In overturning moment calculations, overturning moments due to deadioad and vertical accelerations are not included.
4.
With regard to wind design, the variation of wind pressure with height and the effects of gust are not considered. Also, the effects of shape are not considered.
- Uniform Building Code
Pagy 2 of Enclosure 5.
It has been stated that the crane always " wind mills" with trolley jib in wind direction. However, the basis for this statement is met
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explained.-
6.
The analysis for tornado considerations indicate that the tower would collapse at 130 mph. The staff feels that a more rigorous and de-.
tailed analysis may predict lower speeds.
7.
The method of analysis to assure structural adequacy against crane impact is not clear. Variables and applicable units are not identified.
Explanation is needed for the values "used in equations, e.g., how the value of I is calculated in computing deflections.
B.
REQUEST FOR ADDITIONAL INFORMATION AND RECOMMENDED PROCEDURE 1.
A copy of "Pecco Tower Crane Manual PC1400" is needed for further review.
2.
The performance of the crane in a DBE event should 'be evaluated using procedures outlined in SRP*, Section 3.7.2 with FSAR input. The trolley should be assumed to he at the worst possible location with the maximum lift load. A certain amount of inelastic action can be permitted, providing that safety and stability are assured. Note that buckling of the members may limit the inelastic action. Also, effe:ts of the cable jerking should be evaluated.
3.
The evaluation for the wind loading should be in accordance with SRP, Section 3.3.1.
4 The licensee's analysis postulating possible impact loads and the structural I
t
o Page 3 of Enclosure
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response to these loads is not acceptable to the staff.
If struc-tures are to resist impact loads from crane collapse, the procedures
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1 given in SRP, Section 3.5.3 to predict overall and local damage should be used.
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5.
For each applicable SRP lted and loading combination, the structural adequacy of the crane me76ers s'hould be discussed.
l 6.
The adequacy of the foundation in terms of overturning, sliding, and flotation should be addressed. Criteria and appropriate loading combin-ations are given in SRP, Section 3,8.5.
Also, the structural design
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of the foundation should be discussed.
7.
Discussion of the QA/QC procedure used in manufacturing / erection of this crane structure, along with the comparison to the applicable re-quirements of Appendix B of 10 CFR-50 should be provided.
8.
The crane tower should be secure against collapse under tornado loading.
Please propose measures to b'e taken during a tornado " watch." Your proposal might include such compensating measures as ~ lowering any crane loads or providing additional crane tiedown wires during the tornado watch.
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