ML20098H199
| ML20098H199 | |
| Person / Time | |
|---|---|
| Site: | Seabrook  |
| Issue date: | 08/21/1984 |
| From: | Devincentis J PUBLIC SERVICE CO. OF NEW HAMPSHIRE, YANKEE ATOMIC ELECTRIC CO. |
| To: | Knighton G Office of Nuclear Reactor Regulation |
| References | |
| SBN-705, NUDOCS 8409120148 | |
| Download: ML20098H199 (5) | |
Text
.
' PUBLIC SEAVICE SEWOOK STATION Engine cing office:
Company of New Hampshire 1671 Worcester Road Fromingham. Maisochwietti 0170i (6171 - 872 8100 August 21, 1984 SBN-705 T.F. B7.1.2 United States Nuclear Regulatory Commission Washington, D. C.
20555 Attention:
Mr. George W. Knighton, Chief Licensing Branch No. 3 Division of Licensing
References:
(a) Construction Permits CPPR-135 and CPPR-136, Docket Nos. 50-443 and 50-444 (b) NUREG-0896, " Safety Evaluation Report Related to the Operation of Seabrook Station Units 1 and 2",
dated March 10, 1983 (c) PSNH Letter, dated August 9,1984, " Alternate Pipe Break Design Criteria" J. DeVincentis to G. W. Knighton
Subject:
Safety Evaluation Report (SER) Outstanding Issue No. 5,
" Loading Combinations, Design Transients, and Stress Limits"
Dear Sir:
In response to Safety Evaluation Report Outstanding Issue No. 5, which is delineated in Section 3.9.3.1, Reference (b), the Public Service Company of New Hampshire (PSNH) will summarize herein the methodology employed to ensure functional capability of essential ASME Class 1 piping at Seabrook Station.
This summary is derived from an evaluation performed for PSNH by the Westinghouse Electric Corporation. This evaluation was based on the assumption that NRC approval has been granted for postulated Reactor Coolant Loop (RCL) pipe rupture elimination through the application of mechanistic fracture mechanics techniques.
In Reference (c), PSNH requested that the Staff grant partial exemption from 10CFR50 Appendix A, General Design Criteria 4 (GDC-4) requirements for postulating breaks in RCL piping. Therefore, the validity of this report is contingent on your approval of this exemption request. Similar CDCR-4 exemption requests have already been approved for other utilities.
The analysis contained in the W report was performed for essential Class 1 piping systems for which functional capability must be demonstrated.
These piping systems were evaluated to the following three stress criteria:
1.
The ASME Boiler and Pressure Vessel Code,Section III, 1971 Edition, up to and including Winter 1972 Addenda. Subsection NB and Appendix F.
This is the code of record as indicated the Seabrook FSAR.
\\
8409120148 840821 hDRADOCK 05000443 1
PDR k
United States Nuclear Regulatory Commission August 21, 1984 Attention:
Mr. George W. Knighton, Chief Page 2 2.
The ASME Boiler and Pressure Vessel Code,Section III, 1980 Edition, up to and including Winter 1981 Addenda, Subsection NB, Level C primary stress limits.
3.
Westinghouse recommended Criterion for functional capability of class 1 piping.
This criterion is included as Attachment A.
Having evaluated the results of the W report, PSNH has concluded that functional capability of essential Class 1 Piping Systems has been sufficiently demonstrated.
Justification for this conclusion is based on:
1.
The ASME Code evaluations were performed for approximately 4300 analysis points and of these only six analysis points exceeded the criteria allowables. The number of piping components (six) that exceeded criteria allowables were very few relative to the total number analyzed.
2.
For the six points that exceed criteria allowables:
a.
The maximum margin above Criterion 2 allowables was less than 9%.
b.
The maximum margin above Criterion 3 allowables was less than 3%.
3.
The resultant deformation of the piping components et these points would be minimal.
4.
Flow area for thick-walled piping components, in this case all being concentric reducers, not elbows, is not significantly reduced even for large displacements.
Consequently, PSNH feels that the functional capability of essential class 1 Piping Systems has been sufficiently demonstrated. Your prompt review of this letter is requested.
Very truly yours, YANKEE ATOMIC ELECTRIC COMPANY A
{g' Engineering.andLicensing
.ohn DeVincentis, Director Attachment cc: Atomic Safety and Licensing Board Service List i
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-William S. Jordan, III
Diana Curran
' Hnnnon, Wsias & Jordnn 20001 S Street N.W.
Brentwood Board of Selectmen Suite 430 RED Dalton Road Brentwood, New Hampshire 03833 Washington, D.C.
20009 Roy P. Lessy, Jr., Esquire Office of the Executive Legal Director Edward F. Meany U.S. Nuclear Regulatory Commission Designated Representative of Washington, DC 20555 the Town of Rye 155 Washington Road Robert A. Backus, Esquire Rye, NH 03870 116 Lowell Stree:
P.O. Box 516 Calvin A. Canney Mancehster, NH 03105 City Manager City Hall
. Philip Ahrens, Esquire 126 Daniel Street Assistant Attorney General Portsmouth, NH 03801 Department of the Attorney General Augusta, ME 04333 Dana Bisbee, Esquire Assistant Attorney General Mr. John B. Tanzer Office of the Attorney General Designated Representative of 208 State House Annex the Town of Hampton Concord, NH 03301 5 Morningside Drive Hampton, NH 03842 Anne Verge, Chairperson Board of Selectmen Roberta C. Pevear Town Hall Designated Representative of South Hampton, NH'03642 the Town of Hampton Falls Drinkwater Road Patrick J. McKeon Hampton Falls, NH 03844 Selectmen's Office 10 Central Road Mrs. Sandra Gavutis Rye, NH 03870 Designated Representative of the Town of Kensington Carole F. Kagan, Esq.
RFD 1 Atomic Safety and Licensing Botrd Panel East Kingston, NH 03827 U.S. Nuclear Regulatory Commission Jo Ann Shotwell, Esquire Assistant Attorney General Mr. Angie Machiros Environmental Protection Bureau Chairman of the Board of Selectmen Department of the Attorney General Town of Newbury One Ashburton Place, 19th Floor Newbury, MA 01950 Boston, MA 02108 Town Manager's Office Senator Gordon J. Humphrey Town Hall - Friend Street U.S. Senate Amesbury, Ma.
01913 Washington, DC 20510 (Attn: Tom Burack)
Senator Gordon J. Humphrey 1 Pillsbury Street Diana P. Randall Concord, NH 03301 70 Collins Street (Attn: Herb Boynton)
SEabrook, NH 03874 Richard E. Sullivan, Mayor Donald E. Chick City Hall Town Manager Newburyport, MA 01950 Town of Exeter 10 Front Street Exeter, NH 03833-
's ATTACHMENT A Westinghouse Criteria for Demonstrating Functional Capability of Class 1 Piping Systen:s 5-Included herein are proposed Westinghouse criteria for demonstrating thef functional capability of Class 1 piping.
These criteria apply to piping systems with P/t i 16.
A.
For elbows and bends, functional capability may be considered
. assured when the following requirement is met:
8
+8 1
1.8 S 1
2 y
where 83 = (4.1 + 0.4) and 0 1 5) 1 5
0 and 8) = 0.5 for 82 = 1.0 1
M3 7 3/h for e, >90' Eg=}0.M 5 h. m > for a, = E' 0
41.0 for s, = 0*,
but not less than 1.0 linear interpolation may be used forR* e, c 90*
h.= $,where D[ w outside diameter of pipe, in.
In Of
- faside diameter of pipe, in.
~
t
= nominal pipe well thickness, in.
R.
= bend radius of curved pipe or elbow, in.
r, = mean pfpe radius = (D,-t)/2, in, s,
= bend angle,deg.
Other terms defined in NB-3652, I = f,in.3.
o
~.
t 2
i 8.
For straight pipes, girth butt weld, girth fillet weld, girth socket weld connections, tapered transitions and longitudinal butt welds, functional capability my be considered assured when the following requirement is met:
2 PD 28)
+8 2 1 I'8 Iy
= 0.5 B2 = 1.0
[whereZ=Tr,2t. r,is pipe mean radius and t is the thickness of the pipe..
C.
For branches and tees, functional capability can be considered assured if the following conditi6n is met:
E PD 4M 28)
+8 1
1 8S 2b { +
y dere B, B2b' 02r, Z and Z,'are defined in NB-3650 of the ASE j
b Section III Code of the 1983 Edition.
D.
For reducers, functionaLMility can be considered assured when the following requirteient is. net:
+B {s1.8S 25) 2 y
)
e
\\
1 where B; = 0.5 for a 1 30* and 1
p' B) = 1.0 for a >30*
82 = 1.0 j
= W r,2 and I g
whom,a = cone angle of reducer, deg.
E.
For bolting of flanged joints, functional capability can be considered assured whert the Level D requirements of ASE SEction III Code 1983 Edition (NB-3658) are met.
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