ML20210S443
| ML20210S443 | |
| Person / Time | |
|---|---|
| Site: | Washington Public Power Supply System |
| Issue date: | 02/22/1978 |
| From: | Hosler A WASHINGTON PUBLIC POWER SUPPLY SYSTEM |
| To: | Cox T NRC |
| References | |
| CON-WNP-1394 NUDOCS 8605290173 | |
| Download: ML20210S443 (1) | |
Text
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Februsry 22, 1978 10:
loc. Cox - NRL Fk(fi:
A.G. liusler - WPP55 9
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UPP[R tiDi LEG LOOP 0$!NC 2.4 6 NO Eq#T106 (10),112) A!O (13) Of NB 3-1 In the WNP-l/4 P'5E we comit to I!rgulatnry Guide 1.46 which spebifies the allw;ble stress range for ferritic steel as 2.0 k.
EB 3-1 specifies an ollutable stress range of ?.4 Sm for all materials (El.b (1).(a)).
further, for postulation of tre4Ls, PB 3-1 allows calculated equation (10) stre',ses to eneed ?.4 5,,, pro.'ided, they are less than 3.0 h and if the COI is less thbn 0.1.
If greater than 3.0 Se, stresses calculated by.
equations (12) and (13) talen fr.dividually should be less than 2.4 % and
(!!! should be less tian 0.l.
If not, breali shall be postulated.
(B.1,b t
(1) (t,)).
fi:,uth referente> tu equotion nua,bers and Corresponding stress range allow bles are r.de in Regulatory Gu'de 1.46.
Also, MIB 3-1 invokes these rules speiiiwally f or Cla:.s 1 piping betwien contaltioent isolation valves.
I We under star.J, ho,awr, thot the fikC will dllos application of the above to Ru piping.
If this is true, we need not' postulate split breaks in the uppir but leg of thi M 5 (candy cane); the hot leg loup restraints provided to re, train out ot-plate roover,ent due to the split breaks my be eliminated b elininote these U.'i re.traints tor 'd -l we need Ni:C concurrence that th pipe bre:L rules of P. B 3-1 cay Le used for priury coolant piping; specifi tallytheuseofthe2.45,..stresslimitonferriticandtheuseof equ3tions (10)
(12) en) (13).
Rules regarding nuder of break locations a types of breab will follw those listed in REB 3-1 for Class 2 and 3 pipin 8605290173 780222 PDR ADOCK 05000460 A
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