ML20237J591
| ML20237J591 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 08/21/1987 |
| From: | Hukill H GENERAL PUBLIC UTILITIES CORP. |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| Shared Package | |
| ML20237J594 | List: |
| References | |
| 5211-87-2163, NUDOCS 8708260229 | |
| Download: ML20237J591 (5) | |
Text
p GPU Nuclear Corporation
'. NggIgf Post Office Box 480 Route 441 South Middletown, Pennsylvania 17057 0191 717 944 7621 TELEX 84 2386 Writer's Direct Dial Number:
August 21, 1987 5211-87-2163 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555 Gentlemen:
Three Mile Island Nuclear Station, Unit 1 (TMI-1)
Operating License No. DPR-50 Docket No. 50-289 Asymmetric LOCA Loads This letter is being submitted to provide tne additional information concerning TMI-1 Asymmetric LOCA Loads as requested by Mr. G. Edison, NRR Senior Project Manager, TMI-1, via letter dated July 2,1987. The specific information requested is contained in the two (2) attachments.
Sincerely,
. D.
kill, Jr.
Vice President and Director, TMI-l HDH/JCA:jh 5163g/0972A Attachments cc:
R. Conte, NRC J. Stolz, NRC W. Russell, NRC G. Edison, NRC 8708260229 870021 DR ADOCK 0500 9
O g
GPU Nuclear Corporation is a subsidiary of the General Public Utilities Corporation j
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ATTACHMENT 1-1.
Required Factors of Safety Against Pipe Break Using Two (2) Failure Mechanisms.
Results from the. structural analysis using the two (2) failure mechanisms are presented in Table 1.
Ductile tearing as the failure mechanism is used to calculate the factor of safety associated with ultimate capacity given the maximum loading (moment) on the pipe section containing the 10 gpm crack.
Ductile tearing is also used to calculate the factor of safety associated-with ultimate capacity for the limiting crack size given the i
maximum -loading. This failure criteria is used for both the 28" & 36" t
straight pipe sections. Pipe elbows were not found to be limiting.
Net Section Collapse (NSC)'is the other failure mechanism used to determine the flawed pipe ultimate capacity for the same conditions.
Factors of safety were calculated for both load and flaw size. Comparison of the results of the TMI-1 specific analysis with the NUREG 1061, Volume 3 required factors of safety shows that the TMI-1 results exceed the NUREG 1061 requirements for both failure mechanisms.
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1 2.
Suitability of Material Properties Used In the Leak-Before-Break Analysis l'
l In order to satisfy several criteria needed to establish suitability of material properties, each material used for RCS straight pipe and elbow sections (as well as weld metal) was characterized by physical properties at service temperature conditions.
In addition, the development process for these properties was screened for implementation of 0A and minimum l
number of heats in the data base (three heats required).
Only one weld metal material satisfied all of the criteria. This result led the B&WOG to conduct a materials testing program as part of the Leak-Before-Break (LBB) generic analysis.
The limiting value for a specific material proparty was used in the generic analysis. The NRC staff SER accepting the B&WOG generic report concluded that the material properties data base is suitable for use in the LBB analysis and that the choice of limiting material properties is satisfactory. As part of the TMI-1 specific LBB analysis, the piping j
materials and field weld data were checked and were found to be bounded
)
by the material used in the original LBB analysis, i
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TABLE 1 STRUCTURAL ANALYSIS RESULTS Safety Factor on Maximum Loadings NUREG 1061, Vol. 3 Requirements TMI-l Specific Analysis Results 28 " Straight Pipe 1.414 1.94 36" Straight Pipe 1.41 4 2.35 Safety Factor on Flaw Size NUREG 1061, Vol. 3 Requirements TMI-1 Specific Analysis Results 28" Straight Pipe 2.0 3.12 36" Straight Pipe 2.0 3.73 Safety Facor of Limit Load Analysis NUREG.1061, Vol. 3 Requirements TMI-1 Specific Analysis Results 28" Straight Pipe
- Limit MOM / APP MOM 3.0 4.3
- CRIT Flaw /10 GPM Flaw 3.5 36" Straight Pipe
- Limit MON / APP MOM 3.0 6.1
- CRIT Flaw /10 GPM Flaw 4.4
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ATTACHMENT 2