ML20136C917
| ML20136C917 | |
| Person / Time | |
|---|---|
| Site: | 05000000, Vogtle |
| Issue date: | 10/02/1984 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML082840446 | List:
|
| References | |
| FOIA-84-663 NUDOCS 8601040003 | |
| Download: ML20136C917 (2) | |
Text
.. _ - -
, sr.
p Attachment Georgia Power Company Vogtle Electric Generating Plant Unit Nos. 1 and 2 Docket Nos. 50-424/425 Materials Engineering Branch Safety Evaluation Report
[
PUMP FLWHEEL INTEGRITY The safety objective of this review is to assure that the integrity of the l
primary reactor coolant pump flywheel is maintained to prevent failure at p _
normal operating speeds and speeds that might be reached under accident con-ditions and thus preclude the generation of missiles.
The basis for review is outlined in Standard Review Plan (SRP), Section 5.4.1.1 and the Regulatory Guide 1.14, which describes and recommends a method acceptable to the NRC staff in implementing General Design Criterion 4, r.O
" Environmental and Missile Design Bases," of Appendix A of 10 CFR Part 50 with regard to minimizing the potential for failure of flywheels of the reactor coolant pump.
I EVALUATION I
a)
Materials and Fabrication Flywheels are fabricated from SA-533, Grade B, Class I steel and consist of 4
lj two thick plates bolted together.
The material is vacuum-melted with a l
degassing process.
The materials, as well as finished flywheels, are sub-jected to 100 percent volumetric ultrasonic inspection using procedures and i
acceptance standards specified in Section III of the ASME Code.
The nil-ductility transition temperature (NOTT) of the flywheel material is i
no higher than 10*F.
The Charpy V-notch energy level is at least 50 foot-pounds in the WR orientation at 70 F.
Hence, the RT f 10 F can be assumed.
NOT l
~
8601040003 851127 PDR FOIA BELL 84-663 PDR n.~.-
a
i l
l l b)
Design Basis The calculated stresses at the operating speed, due to centrifugal forces, l
and the interference fit on the shaft are within the Regulatory Guide limits.
j The pump runs at 1190 rpm and may operate briefly at overspeed of 109 per-cent during the loss of offsite electrical power. The design speed is 125 percent of the operating speed. The flywheels are also tested at 125 per-cent of the maximum synchronous speed of the motor. The ccabined stresses at the design overspeed, due to interference fit and centrifugal forces, are within the Regulatory Guide limit.
The flywheels can be inspected by removing the cover. Hence, any crack that developed can be noticed. The critical crack length at the keyways, where the stress concentration is high, is about 6 inches at the design overspeed.
c)
Evaluation We have reviewed the material, fabrication, design and inspection aspects of the pump flywheels for compliance with the Regulatory Guide 1.14. We have concluded that the structural integrity of the flywheels is adequate to withstand the forces imposed by overspeed transients without the loss of function, and the integrity will be verified periodically by inspection to assure that the integrity is maintained.
P R
i
[
, c. 5 = s-i f?%jo, UNITED STATES y h, NUCLEAR REGULATORY COMMISSION j
- gy$.,,g,g i
j s?42 WASHINGTON. 3. C. 20555 l
s p' <s% / g g, w/
CCT 2 1984
'M Docket Nos. 50-424/425 l
l MEMORANDUM FOR:
Thomas M. Novak, Assistant Director d
for Licensing Division of Licensing i
FROM:
William V.'Johnston, Assistant Directer Materials, Chemical & Environmental Technology Division of Engineering
SUBJECT:
PUMP FLYWHEEL INTEGRITY - V0GTLE UNITS 1 AND 2 Plant Name: Vogtle Electric Generating Plant, Units 1 and 2 Suppliers: Westinghouse Licensing Stage:
OL Docket Nos.: 50-424/425 Responsible Branch & Project Manager:
LB #4, M. Miller Reviewer:
S. J. Bhatt i
~
. Requested Completion Date:
September 30, 1984 Description of Task:
SER Input - Pump Flywheel Integrity f'S Review Status:
C wplete The Component Integrity Section of the Materials Engineering Branch, l
Division of Engineering, has reviewed the FSAR Section 5.4.1.1, " Pump Flywheel Integrity."
Based on our evaluation, we conclude that the flywheel material and design of the pump-motor assembly at Vogtle Units 1 and 2 a.re acceptable. Our
.i Safety Review is attached.
) '[g/[t.a.s.
l
. *- % - ^
William V. Johnston, Assistant Director Materials, Chemical & Environmental Technology l
Division of Engineering l
j
Attachment:
As stated cc:
R. Vollmer B. D. Liaw D. Eisenhut W. Hazelton E. Sullivan R. Klecker S. Pawlicki C. Cheng E. Adensam S. Bhatt l
M. Miller I
i l 1A A A /1 m
. a j
v WV V V V vvlh i
o40
\\\\3 e
/
N-