NRC Generic Letter 1981-11
| ML031080531 | |
| Person / Time | |
|---|---|
| Issue date: | 02/20/1981 |
| From: | Eisenhut D Office of Nuclear Reactor Regulation |
| To: | |
| References | |
| NUREG-0619 GL-81-011 | |
| Download: ML031080531 (6) | |
UNITED STATES
NUCLEAR REGULATORY COMMISSION
£ XWASHINGTON. 0. C. 20555
.. February 20, 1081 ALL POWER REACTOR LICENSEES AND LICENSE APPLICANTS (Generic Letter 81-11)
By letter dated November 13, 1980 you were forwarded a copy of NUREG-
0619, "BWR Feedwater Nozzle and Control Rod Drive Return Line Nozzle Cracking" (November 1980). An error has been found in footnote 2 to Table 2 on page 18 of NUREG-0619. Because of the deletion of leak- testing requirements, footnote 2 should now read: "To be performed even if UT results are satisfactory." Please make the change in your copy of the NUREG.
Also, cornents received from GE and others since the publication of NUREG-0619 note the difficulty in meeting the requirements for a low flow controller as described in Section 4.2 on page 16 of the NUREG.
The comments specifically address the requirement for a controller having the six characteristics stated in Section 3.4.4.3 of the GE
report NEDE-21821-A (BWR Feedwater Nozzle/Sparger Final Report, February
1980). They note that an existing controller may not meet the six characteristics, yet the feedwater system may in fact meet the criterion of the crack growth analysis from which the characteristics were derived (assurance of crack growth to no greater than one inch in forty years).
They also note that strict adherence to the defined characteristics could obviate the beneficia l aspects of another recommended change, reactor water cleanup (RWCU) system rerouting to all feedwater lines, by increasing reactor vessel water level to the extent that discharging of the relatively hot RWCU water is necessary.
We concur in the assessment and will accept continued use of an existing controller (or a controller modified to meet the basis stated above but not possessing all six characteristics of NEDE-21821-A) based upon a plant-specific fracture mechanics analysis or application of the analysis already existing in NEDE-21821-A Section 4. In order to be considered acceptable, this analysis must show that stresses from conservative controller temperature and flow profiles, when added to those resulting from the other crack growth phenomena, such as startup and shutdown cycles, do not result in the growth of a crack to greater than one inch during the forty year life of the plant. The analysis should be submitted as part of the reports required by NUREG-0619.
-2 - February 2'), 1981 Licensees or applicants not desiring to perform such an analysis must meet the stated requirements of Section 4.2 of NUREG-0619, I.e., the installation of a low flow controller having the six characteristics stated in NEDE-21821-Ai In answer to a question that has been raised, NUREG-0619 was forwarded to PWR licensees and applicants for their information only, in con- sideration of the fact that the PWR steam generator feedwater line cracking has been attributed to the same phenomenon of thermal fatigue as existed in the BWR feedwater nozzles. No response from PWR licensees and applicants is required.
Sincerely, rrell . isenhut, Director Division o Licensing cc: Service Lists
rrv ! 7 1981 PLANTS UNDER CP REVIEW
1. Pilgrim 2 50-471
2. Perkins 1/2/3 50- 488, 489, 490
3. Allens Creek 1 50-466
4. Pebble Springs 1/2 50;-514, 515
5. Clinch River 50-537
6. Black Fox 1/2 50-556, 557
7. Skagit 1/2 50-522, 523
FEB 6 7 -2:
PLA?47S UNDER CONSTRUCTION
1. Cherokee 1/2/3 50-491, 492, 493
2. Beaver Valley 2 50-412
3. St. Lucie 2 50-389
41. Vogtle 1/2 50-4 24, 425
51. River Bend 1/2 50-458, 459
61.
71. Forked River 50-363
81. Nine .mile Point 2 50-4 10
91. millstone 3 50-423
10. B3illy 2 50-367
17. Lim.erick 1/2 50-352, 353
12. Eope Creek 1/2 50-354, 355 Seabrook 1/2 50-443, 444
15. Harts.ille 1/2/3/4 50-518, 519, 523, 521
13..
16 Phipps Bend 1/2 50-5 53, 554
14. Yellow Creek 1/2 50-566, 567 WPPSS 1, 3/4/5 50-4 60, 508, 513, 509 Harris 1/2/3/4 50-4 00, 401, 402, 403
20. FNP 50-437
FEBS7791 OPERATING PLANTS
1. Sequoyah 1 50-327
2. Salem 2 50-311
3. McGuire 1 50-369
4. Farley 2 50-364 VP
S
FEb _ 7 1981 PLANTS UNDER OL REVIEW4
1 .4 Clinton 1/2 50-4 61/4 62
2.' Byron 1/2 50-454, 455
3. Braidwood 1/2 50-456/457
4. LaSalle 1/2 50-373, 374
5. Midland 1/2 50-329,330
6. McGuire 2 50- 370
7. So. Texas 1/2 50-498, 499
8. Shoreham 50-322
9. Waterford 50- 382
10. Grand Gulf 1/2 50-416/417
11. Diablo Canyon 1/2 50-275, 323
12. Susquehana 1/2 50-387, 388
13. St. Lucie 2 50-389
14. Summer 1 S0- 395
15. San Ono.'re 2/3 50-361, 362
16. Bellefonte 1/2 50-438, 439
17. Watts 5ar 1/2 50-390, 391
18. Sequoyah 2 50- 328
19. Comanche Peak 1/2 50-445, 446
20.
21. WPPSS-2 50- 397
22. Fermi 2 50-34 1
23. Zimmer I 50-338
24. Perry 1/2 50-4 40, 441
25. Palo Verde 50-528, 529, 530
26. Catawba 50-4 13, 414
27. Marble Hill 50-546, 547
28. Wolf Creek 50-4 82
29. Callaway 50-483, 486