ML20198F864
| ML20198F864 | |
| Person / Time | |
|---|---|
| Site: | Washington Public Power Supply System |
| Issue date: | 03/09/1978 |
| From: | Bosnak R Office of Nuclear Reactor Regulation |
| To: | Cox T Office of Nuclear Reactor Regulation |
| References | |
| CON-WNP-1159, RTR-REGGD-01.046, RTR-REGGD-1.046 NUDOCS 8605290124 | |
| Download: ML20198F864 (3) | |
Text
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MAR 9 1978
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MEMORANDUM FOR!
T. H. Cox, Light Water Reactors Branch #3, DPM l
FROM:
R. J. Bosnak, Chief, Mechanical Engineering Branhh, DSS SUBJECI:
IMUIRT BY WFPSS CONCERNING TIIE USE OF BTP ME3 3-1 AND i
R.G. 1.46 The Mechanical Engineering 3 ranch have reviewed the February 22, 1978 l
inquiry by UPPSS concerning the use of BTP MEB 3-1 and R.G.1.46 which was forwarded by your memorandum dated February 24, 1978.
A proposed reply is attached. This reply reflects the position contained in a proposed revision to BTP MEB 3-1 which is currently undergoing the final phases of management approval. As such, it contains the criteria by which the WPPSS 1 & G FSAR's will be judged when they are docketed.
R. J. Bosnah, Chief Mechanical Engineering Eranch Division of Systems Safety ec w/ enc 1:
Contact:
R. Mattson, SS R. J. Kiessel D. Vassallo, FM Ext. 27538/72 J. Knight, SS
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e MECHANICAL ENGINEERING BRANCH DIVISION OF SYSTEMS SAFETY MAR 9 8 78 PROPOSED REPLY Your inquiry of February 22, 1978, requested permission to postulate pipe break locations in the RCS piping based on the criteria contained in Branch Technical Position MEB 3-1.
This would be in lieu of using the criteria contained in Regulatory Guide 1.46 as committed to in the WNP-1/4 PSAR.
Since BTP ME3 3-1 only addresses ASME Class 1 piping within the contain-ment penetration area, you proposed to apply several criteria applicable to ASME Class 2 and 3 piping as well.
The composibacriteria proposed does not adequately cover two aspects which we feel are a necessary part of an acceptable postulated pipe break criteria for ASME Class 1 piping. Combining these aspects with your proposal yields the follosing acceptable criteria:
"In lieu of the postulated pipe break criteria contained in Regulatory Guide 1.46, breaks in the RCS piping should be postulated at the following locations in each piping run or branch run:
(a) At terminal ends of the run; (b) At intermediate locations between terminal ends where the stress intensity range (including the zero load set) as calculated by equation (10) and either equation (12) or (13) in ASME Code Section III, Paragraph NB-3653 exceeds 2.4 S, for normal and upset plant
m 2-MAR 9 1978 conditions:
(c) At any intermediate locations between terminal ends where the cumulative usage factor derived from the piping fatigue analysis under the loadings resulting from plant normal, upset and testing conditions exceeds 0.1; (d) In the event that two intermediate locations cannot be determined by the stress or usage factor limits described above, the two locations of highest stress, as calculated by equation (10) in ASME Code Section III, Paragraph NB-3653, which are separated by a change in direction of the pipe run shall be selected.
If the piping run has only one change or no change of direction only one intermediate break need be postulated. A given elbow or other fitting (tee, reducer, etc.) shall be considered as a single break location regardless of the number of types of breaks postulated at the fitting."
Should you decide to use this criteria, this fact, along with the criteria, should be so s,tated in Section 3.6.2 of the WNP-1/4 FSAR.
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