ML20235N864
| ML20235N864 | |
| Person / Time | |
|---|---|
| Site: | Callaway  |
| Issue date: | 07/10/1987 |
| From: | Capone D UNION ELECTRIC CO. |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| ULNRC-1542, NUDOCS 8707200254 | |
| Download: ML20235N864 (2) | |
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s' UNION EHCTINC COMPANY
_ CaWowayPlant; y.-
July 10,1987 :
-ULNRC-1542' l
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9 Nuclear Regulatory Commission Office of Nuclear Reactor Regulation Washington,.DC.-20555 REQUEST TO REVIEW INTERPRETATION TO LEAVE LEAK CHASES PLUGGED DURING AN ILRT (Ref.: NRC Open Item 463/87006-03)
Callaway Plant's containment liner has leak chases in the following areas:
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- 1) on the. floor plate over all welds
.2) on the liner wall covering some welds of the liner and liner reinforcing inserts.
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Many of the leak chase channels are not accessible and cannot be vented j
during a containment Integrated Leak Rate Test (ILRT).
Some of the test' plugs for the leak chases.are under embedded plates, some were covered with the final concrete finishing, some have structural steel preventing access Lto. the plugs and some are in Very High Radiation Areas (in the j
instrument tunnel, under the reactor vecsel).
It'is the interpretation of Union' Electric that the. combined liner j
butt weld along'with the associated pre-tested channel' fillet welds and'
-leak test connections c.onstitute the actual containment boundary in post l
accident conditions.- Concurrence with this interpretation'is requested
.j based on the following:
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- 1) All leak chases installed were leak tested during initial installation of the containment liner. According to construc-tion specification C-151A and the applicable design drawings, a Halogen Leak test per T1040 or T1050 or an Air Test per T1030 of Section V of the applicable ASME code was performed. This initial leak test verified the satisfactory installation of all Leak Channels.
- 2) All leak channels are a minimum of 3/16 inch channel or angle with'3/16 inch seal welds to attach to the liner plate.
(The welds were tested as described above.) This construction is sufficient to retain the accident pressure of 48.1 psig (Pa).
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MoHing Address:P.O. Box 620 Futton,MO65251
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'ULNRC-1542 July 10,1987 Page 2-l D
- 3) All test connections consist of 1/4 inch NPT square head plugs.
0 ANSI B16.14 cnd B16.4 rate the plugs at 400 psig at 140 F and 250 psig at 4000F, This is sufficient to seal against an acci-dent pressure of 46.1 psig.
The above factors indicate that the leak chases are acceptable for retaining design accident pressure.
Additionally, the accident condition of all these leak chases will be with the test plugs installed (the leak chase NOT vented). Conse-quently, performing an ILRT with the test plugs installed will test the containment boundary in its accident condition.
If the leak chases are all leak tight, they will then be pressure tested by the ILRT.
If, however, a leak chase were not leak tight, the ILRT will also be testing the liner weld underneath the leak chase.
Therefore, taking credit for the leak chase integrity during the ILRT will be consistent with the intent of 10CFR50 Appendix J to test the containment boundary in its post-accident condition.
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D. W. Capone N/DLB/TMD/lak cc: USNRC Region III USNRC Resident Inspector, Callaway USNRC Licensing Project Manager (T. W. Alexion) l l