ML20057C472
| ML20057C472 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 09/23/1993 |
| From: | William Cahill, John Marshall TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| TXX-93290, NUDOCS 9309290005 | |
| Download: ML20057C472 (4) | |
Text
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gd Log # TXX-93290 File # 10010
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Ref. # 10CFR50.55a r
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TUELECTRIC September 23, 1993 William J. Cahill, Jr.
Gump s*we Persident U. S. Nuclear Regulatory Commission Attention:
Document Control Desk Washington, DC 20555
SUBJECT:
COMANCHE PEAK STEAM ELECTRIC STATION (CPSES)
DOCKET NO. 50-445 UNIT 1 INSERVICE INSPECTION PROGRAM RELIEF REQUESTS Gentlemen:
The purpose of this transmittal is to submit relief requests A-1 and A-2 to certain inspection requirements of Section XI of the ASME Boiler and Pressure Vessel Code.
These requests are included as Attachments 1 and 2, respectively, to this transmittal.
TV Electric requests your approval of these relief requests by October 30, 1993.
If you have any questions. please contact Mr. Carl B. Corbin at (214) 812-8859.
Sincerely.
William J. Cahill, Jr.
Y By:
J. S. Marshall Generic Licensing Manager CBC/cbc Attachments c
Mr. J. L. Milhoan. Region IV Mr T.
A.
Bergman, NRR Mr. G.
Bynog TDLS Resident Inspectors (2)
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A*ttachment I to TXX-93290-Page 1 of 1 RELIEF REQUEST-
- i A-1.
A.
Item (s) for which relief is requested:
Pressure retaining bolted connections.
B.
Item (s) Code Class:
1, 2 and 3 C.
Examination requirement f rom which relief is requested:
ASME Section XI 1986 Edition no Addenda.
l Subparagraph IWA-5250 (a) (2) requires bolting to be removed and VT-3 visually examined for corrosion when leakage occurs at a bolted connection.
D.
Basis for relief:
The time and radiation exposure associated with removal of all bolting at a connection is not warranted to determine the condition'of the bolted connection.. Removal of 1 bolt at the position closest to the leakage source will reveal sufficient evidence to indicate the overall condition of the bolted connection.
Leakage does not typically occur. in a uniform pattern around a bolted connection, but rather in a localized area along the-perimeter.
The bolt closest to the leakage source will be most susceptible to damage.
E.
Alternate examinations:
it is proposed that subparagraph IWA-5250 (a) (2) of the 1990 Addenda be utilized in lieu of this same paragraph from the 1986 Edition..The 1990 Addenda allows for removal and examination of the bolt closest to the leakage source.. Examination of the remaining bolting.is contingent-upon j
the condition of the examined bolt.
i F.
Anticipated impact on the overall level of. plant quality and safety:
None I
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Page 1 of 1
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. to TXX-93290' Page 1 of 2 RELIEF REQUEST A-2 i
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A.
Item for which relief is requested:
insulated bolted connections in systems which are borated for the i
purpose of controlling reactivity.
-i B.
Item Code Class:
1 C.
Examination requirement from which relief is requested:
l ASME Section XI 1986 edition, no Addenda.
Subparagraph IWA-5242 (a) requires that. *for-systems borated for the purpose of controlling reactivity, insulation shall be removed from pressure retaining bolted connections for visual examination VT-2".
O.
Basis for relief:
l System leakage tests are conducted when the Class 1 pressure boundary is raised to nominal operating pressure and temperature as part of normal startup following a refueling outage.. Removal and reinstallation of f
insulation under nominal operating temperature creates a hardship due to.
j the extreme heat.
Cooling down to a temperature of 200 F, as allowed by IWA-5245 would unduly extend the outage duration due to heatup/cooldown rates, as well as introduce additional thermal cycles.
Addi.ti ona lly.
radiation levels are typically higher during startup than during-shutdown.
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Significant leakage from insulated bolted connections will be apparent at exposed insulation joints and surfaces and would be detected lduring'a l
VT-2 examination of these insulation joints and surf aces.
Programs which were developed in response to Generic Letter 88-05 are currently in place to address the potential for corrosion of carbon
-i stee1 portions of the reactor coolant pressure boundary when exposed to j
concentrated boric acid.. Examinations conducted in accordance with ASME j
Section XI. designed to detect boric acid corrosion of the primary j
system serve to enhance these, programs but are not required to ensure effective programs.
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'Page 1 of 2 i
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o 4 to TXX-93290 Page 2 of 2 RELIEF REQUEST A-2 (cont.)
E.
Alternative examinations:
It is proposed that rather than removing / installing insulation at bolted connections during the inservice leak test performed at plant startup..
the insulation shall be removed and the connection examined during refueling.
The bolted connection shall be examined for evidence of leakage during each refueling outage by VT-3 certified personnel. Any evidence of leakage will be evaluated in accordance with IWA-5250 (a)
(2).
During the inservice leak test, the exposed insulation surfaces and joints at bolted connections shall be examined via a VT-2 examination to ensure that no significant leakage exists.
F.
Anticipated impact on the overall level of plant quality and safety:
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Page 2 of 2
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