ML20215B038
| ML20215B038 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 12/04/1986 |
| From: | Thornton A BALTIMORE GAS & ELECTRIC CO. |
| To: | Mcneil S Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8612120013 | |
| Download: ML20215B038 (2) | |
Text
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BALTIMORE d
' OAS AtaD ELECTRIC CHARLES CENTER P.O. BOX 1475 BALTIMORE, MARYLAND 21203 NUCLEAR ENGINEERING SERVICES DEPARTMENT 4
' CALVERT CUFFS NUCLEAR POWER PLANT.
. LUS8Y, MARYLAND 20057
' December 4, 1986 U.S. Nuclear Regulatory Commission Office of Nuclear Reactor Regulation Washington,' D.C.
20555
~ Attention:
Mr.-S. A. McNeil,.PWR Project Manager Directorate #8 DW of.PWR Licensing B
Subject:
Calvert' cliffs Nuclear Power Plant Unit Nos.
1 & 2; Docket Nos. ' 50-317'& 50-318 Inservice Inspection Program
Reference:
Letter Dated ~ October.2,.1986.from J.aA. Tiernan to A.
C. Thadani
Dear Mr. McNeil:
The referenced letter requested relief from two ASME Code Section XI requirements.
This' letter provides additional information concerning the request for relief from performing a volumetric exam on Control Rod Drive Housing Welds.
~During the present Unit 1 refueling outage an attempt was made to perform the surface exams on Control Rod Drive Housing Welds that we had proposed in lieu of the volumetric examinations.
Due to the design geometry of the component, 100% coverage was not obtainable on the. required three Control Rod Drive Housings.
Additional Control-Rod Drive Housing welds were examined to accomplish an equivalent of three welds.
The Code requires that ten percent of the peripheral Control Rod Drive Housing welds be examined.
Since there are
~
28 peripheral housings, three were selected to be examined.
After removal of the reactor vessel head shroud and insulation it - was discovered that only part of the welds could be examined.
The welds are partially obstructed because they l
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Mr. S. A.-McNeil December 4, 1986 Page 2 extend into - the~ reactor head itself.
In order. to - meet the
-intent of the requirements, additional Control-Rod Drive Housing welds.were examined to make an-equivalent of three
-100% examinations.-
This was satisfied by examining three
. welds.75% and two welds greater than 50%.
- At this time. we again examined the feasibility of performing an ultrasonic or radiographic examination and confirmed-the impracticability due to access and design geometry.
We ask that you consider the variation of examining mo'e r
than-three welds to gain equivalent coverage.
Should you have any questions, do not hesitate to contact us.
Very truly-yours,-
A. R. Thornton General Supervisor Plant and Project.. Engineering ART /jla cc:
D. A. Brune, Esquire J. E. Silberg, Esquire T. Foley, NRC L-
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