ML20151H604
| ML20151H604 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 04/15/1988 |
| From: | Counsil W TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC) |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| Shared Package | |
| ML20151H605 | List: |
| References | |
| TAC-R00341, TAC-R341, TXX-88382, NUDOCS 8804200444 | |
| Download: ML20151H604 (2) | |
Text
__. _ _ _ - _ _
==
'~
C C
Log # TXX-88382 7UELECTRIC File # 903.1 clo 903.6 clo Ref f 10CFR50.4(a)
$""*,",tj,1, April 15, 1988 U. S. Nuclear Regulatory Commission Attn: Document Control desk Washington, D.C. 20555
SUBJECT:
COMANCHE PEAK STEAM ELECTRIC STATION (CPSES)
DOCKET N0. 50-445 APPLICATION OF LEAK-BEFORE-BREAK METHODOLOGY TO BRANCH LINES Gentlemen:
By revision to the General Design Criteria 4(GDC-4) of A)pendix A, 10CFR50 (52FR41288), the NRC allowed the use of Leak-Before-Brea( (LBB) methodology in analyzing piping systems for the elimination of the dynamic effects associated with postulated pipe breaks.
This criterion allows demonstration of piping integrity by analysis to serve as a basis for excluding consideration of dynamic effects.
Dynamic effects of pipe ru)ture covered by this rule are missile generation, pipe whirping, pipe brea< reaction forces, jet impingement forces, decompression waves within the ruptured pipe and dynamic or nonstatic pressurization in cavities, subcompartments and compartments.
Enclosed are ten (10) copies of the LBB "CPSES-1 Whipjet Program Report" for your review.
Approval of the attached LBB "CPSES-1 Whipjet Program Report" will allow the elimination of pipe breaks and their associated dynamic effects for the following systems:
1.
Pressurizer Surge Line 14 inch diameter piping from the reactor coolant loop nozzle to the pressurizer nozzle.
2.
RHR Suction Hot leg 12 inch diameter piping from the reactor coolant loop nozzle pipe weld to the inlet weld on valve #8702, excluding the 6 inch diameter safety injection branch connection.
3.
Accumulator injection 10 inch diameter piping from the accumulator tank nozzle piae weld to the loop nozzle pipe weld excluding the 6 inch diameter aran
- line.
eco42gy h
[
PDR A
400 North Ohr Surres LB 81 skil.u. Tew 13201
TXX-88382 April 15, 1988 i
Page 2 The approval of the LBB "CPSES Whipjet Program Report" would not affect the following:
1.
Containment Design will continue to accommodate loss of coolant accidents (LOCAs) resulting from breaks in the reactor coolant pressure boundary up to and including a break equivalent in size to the double-ended rupture of the largest pipe in the reactor coolant system.
2.
Design bases for Emergency Core Cooling System (ECCS) will still retain non-mechanistic pipe rupture.
3.
Environmental qualification of electrical and mechanical equipment.
NRC acceptance of "CPSES Whipjet Program Report" will allow the removal of counter-productive pipe whip restraints; removal of jet impingement shields; increased accessibility and effectiveness of inservice inspections; decrease t
of inservice inspection radiation dosages; and improved construction and maintenance.
We remain available to meet with the staff to resolve any questions which may arise and provide any information necessary to promptly implement the results of this report.
The FSAR will be amended to reflect the revised design bases as a result of implementing LBB methodology once NRC acceptance is granted.
Very truly yours, g49v W. G. Counsil llAM:tgw Enclosure c-Mr. R. D. Martin, Region IV Resident inspectors, CPSES (3) r h