ML20064B176
| ML20064B176 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 09/28/1990 |
| From: | Shelton D CENTERIOR ENERGY |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20064B177 | List: |
| References | |
| 1855, TAC-M77588, NUDOCS 9010150113 | |
| Download: ML20064B176 (4) | |
Text
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j DoneM C. Shahen 300 Madaan Avenue yee premment.Nuciser Toisdo. OH 436524101
~ Davisbases (419)249 2300 Document Number 50-346 License Number NPF-3 1
' Serial Number 1855-I September 28, 1990 j
i United States Nuclear Regulatory Commission b-Document Control Desk' Vashington, D. C.
20555 Silbject:
Request for Relief from ASME Code Section XI Requirements for'VT-2
)
Visual Examination of Class 2 Piping Associated with Containment' n
Penetration Numbers-30, 31, 33 and 34 (TAC Number 77588)
I
' en tlemen t j
l The purpose of this letter is to request relief pursuant to 10 CPR 50.55a(g)(5)(iv) from certain: requirements of Section XI.of the American Society of Mechanical g
Engineers (ASME) Boiler and Pressure Vessel' Code regarding visual examination of-l portions of Class 2 piping associated with containment penetration numbers'30, 31,-.
j 33, and 34 at the Davis-Besse Nuclear _ Power Station (DBNPS). Containment-penetration numbers 30 and 31 are associated with emergency sump recirculation and valves DH9B
.and DH9A, respectively. These valves and piping.are enclosed by guard pipes which
. prohibit performance of a VT-2 visual examination.
Similarly, guardpipes, rubber-foam barriers and rubber boots prevent visual access necessary to perform VT-2 visual
-examination.of the-containment purge piping associated with containment penetration
]
numbers 33 and 34.
3 Toledo Edison personnel discussed the adequacy of_the proposed alternative examinations identified in the attachment with the chairman of the Special Vorking
.i
- Group on Pressure Testing at the ASME Section XI meetings, during the week of August
)
-27,.1990.
Based on' insights gained from this discussion, Toledo Edison has decided-to seek an interpretation from the ASME Section XI Committee that,the examinations performed satisfy Code requirements.
In the interim, pending a favorable interpretation from ASME, pursuant to 10 CFR 50.55a(g)(5)(iv) relief is requested for the first. ten-year interval and subsequent intervals.
9010150133 900928 P
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. Doclict Cumber 50-346
License Number NPF-3 Serial Number 1855 l
Page 2 L
If you have any questions concerning this matter, please contact Mr. R. V. Schrauder, Manager - Nuclear Liccusing, at (419) 249-2366.
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-Very truly yours, LN PVS/mmb l'
Attachment ces P.'M. Byron, DB-1 NRC Senior Resident Inspector A. B. Davis, Regional Administrator, NRC Region III M. D. Lynch, DB-1 NRC Senior Project Manager State of Ohio Utility Radiological Safety Board t
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i Docibt Number 50-346 l
L License Number NPF-3' Serial Number 1855 i
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Relief Request P
Component Description Containment Penetration 31 -~ Emergency Sump Recirculation Line and Valve DH9A i
H enclosed by guardpipe-(Decay Heat Train 1) i l
i Containment Penetration 30 - Emergency Sump Recirculation Line and Valve DH9B enclosed by guardpipe (Decay Heat Train 2)
" ~
'ASME Code Class ASME Section XI, Class 2 Piping ASME Examination Requirements j
Subsection IVC. Table IWC-2500-1 Examination Category C-H, Item No. C7.21, ASME Section XI, 1977 Edition with Addenda through Summer 1978, requires a hydrostatic test per IVC-5222 of.the piping identitled above.
Basis for Relief Due to the guardpipe enclosure, it is not practical to visually examine (VT-2) the, valves and pipe enclosed. However, the guardpipes contain a drain that is opened and-observed for leakage (Note attached drawing, M-283,.CTNT Emergency Sump Recire Valve Enclosure).
Per Toledo-Edison's procedure DB-PF-00204, ASME Section XI Pressure Testing,-the examination'shall consist of examining the enclosure drains for evidence of leakage and that the presence of dampness (not active leakage) shall be 3
acceptable based on successful completion of a pressure test of the guardpipe (e.g., Local Leak Rate Test).
The 10 CFR 50 Appendix ~J local leak rate test pressurires the guardpipe to 38 psig.
The local leak rate tests are mass replacement tests, where test pressure is maintained over a period of time and the flow necessary to maintain pressure is measured. The local leak rate. test is performed at least every two years.
Four tests have been performed since 1985, all resulting in zero leakage.
Al'ternative Examination i
The piping of discussion vill be pressurized to hydrotest pressure. The examination-shall consist of examining the enclosure drains for evidence of leakage.
No active q
1eakage and a successful completion of the 10 CFR 50, Appendix J, local leak rate
. test. vill result in an acceptable test.
i
r Docket Number 50-346 1
d(4 Lic6ns] Numb:r NPF-3 i
Serial Number 1855 P
o h
i Relief Request I
I
-Component Description Containment Penetration 33 - Containment Purge from Valve CV5005 to 1)_. Valve CV5006 (Line HBB-17).
- 2) Containment Penetration 34 - Containment Purge from Valve CV5007 to f
Valve CV5008 (Line HBB-18).
ASME Code Class ASME Section XI, Class 2 Piping l
ASME Examination Requirements Subsection IVC,. Table IVC-2500-1 Examination Category C-H, Item No. C7.21, ASME Section XI, 1977 Edition with Addenda through Summer.1978, requires a hydrostatic test per IVC-5222 of the penetrations identified above.
A pneumatic test is performed as. allowed by IVC-5210 (b).
Basis-for Relief.
Relief is requested from a complete visual VT-2 examination using the soap bubble j
technique on Containment Penetrations 33 and 34.
Due-to the configuration of the pipe, surrounding guardpipes, and five penetration rubber foam barriers and rubber boots, it is not practical to completely use a soap bubble technique with the VT-2 visual examination along the entire length of the
. pipe. Even the removal of the fire penetration barriers and rubber boots vould not allov.for a complete soap bubble technique VT-2 visual examination due to the length of the pipe and lack of clearance between the pipe and guardpipes.
During;the pneumatic test, the accessible velds are examined by the soap bubble technique.- The inaccessible velds are 3ongitudinal velds. The inaccessible veld portions are considered acceptable based on successful completion of the associated local leak rate tests.
Section XI does not provide any guidance for pneumatic testing. Thus, the soap bubble technique has been esed for good practice.
'The 10 CFR 50, Appendix J local leak rate tests pressurizes the system to 38 psig (Design Basis Accident Pressure).
-Alternative Examination
~A pneumatic test vill be performed and visually VT-2 examined by the soap bubble technique for all accessible velds. The inaccessible veld portions shall be acceptable based on successful completion of 10 CFR 50, Appendix J local leak rate tests.
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