ML19345F034

Submits Response to Questions Re Inservice Insp Program, Per 810114 Telcon.Added Justification for Relief Requests Encl

ML19345F034
Person / Time
Site:	LaSalle
Issue date:	02/04/1981
From:	Delgeorge L COMMONWEALTH EDISON CO.
To:	Youngblood B Office of Nuclear Reactor Regulation
Shared Package
ML19345F035	List: ML19345F034 ML19345F038
References
LOD-81-40-7, NUDOCS 8102060562
Download: ML19345F034 (3)

Text

. e Commonwealth Edison One First National Plaza. Chicngo, Illinois Address Reply to: Post Office Box 767

- Chicago. Illinois 60690 February 4,1981 Mr.B5J.Youngblood, Chief Licensing Branch 1 Division of Licensing U.S. Nuclear Regulatory Commission Washington, D.C. 20555

Subject:

LaSalle County Station Units 1 & 2 Response to Questions on Unit 1 inservice Inspection Program, NRC Docket Nos. 50-373/374 LOD 81-40-7

Reference:

January 14, 1981 telecon between L.O. De1 George, G. Crane, R. Hooper (GE) and Messrs. Bournia, Hum, and P. Taylor (NRC)

Dear Mr. foungblood:

The following responses are provided to answer the NRC's questions asked in the reference conference telecon.

1. The LaSalle pre-service inspection was begun in CY1977 on the basis of ASME Section XI 1974 edition through summer 1975 addenda. The RPV data was largely automated data with a capability for automated future comparisons against the base-line data. Multiple head sensors are utilized with multiple data channels per inspection track. The LaSclle practice is consistent with the interpretation by the industry that the ,,re-service inspection anc the inspections in the first ten year interval would utilize che same year edition of the code to establish continuity of observations. D is industry

, practice is not inconsistent with the intent of the ASME code con,ittee; see attached letter f rom L.J. Chockie to W.F. Anderson, dated 27 January 1981.

For LaSalle, the pre-service inspection for Units 1 & 2 was performed with only one code year of ASME XI standards even though that inspection occurred over the th.ee to four year period when the 1977 edition and summer 1978 addenda were circulated for discussion and finally published.

The extent of coverage and the methodology changed between these two issues.

A comparison of coverages is attached where in only the major differences are noted but not the similarities of the two versions. Several of the requirements of the later versions are incorporated in the LaSalle ISI Program although no specific mention is trade to identify them as 578 requirements.

A short paragraph is added to Indicate that the LaSalle ISI program utilizes calibration standards (holes per S75 requirements) which results in approximately twice the UT sensitiv'ty. When coupled with the LaSalle r(

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B.J. Youngblood Ptga Two February 4,1981 ISI procedures (50% DAC), the resultant discriminability is comparable or exceeds that cited in the S78 addenda. This NDE technique was used throughout the preservice baseline inspection for Units 1 and 2 and because its fault discriminability exceed that of S78 requirements, it is the planned technique for the LaSalle ISI Program.

2. Added Justifications for Relief Requests

a. Al Related to ASME IWC - 1220(a), design pressure and temperature; it pertains specifically to the Primary Containment Vent and Purge System. Four 24-inch lines are

, effected. Originally, this relief request number pertained to t

ECCS and applicable portions of the RHR System, but when the Commission denied its use it was deleted in August 1979 The number is now resubmitted but for a non-ECCS, non-RHR system.

It relates to the DC system, a non-ESF system.

b. At LaSalle the UT Indications are recorded at 50%, DAC from calibrations based upon the 1974 version (S75 addenda) of the code where holes are stipulated. The recording sensitivity exceeds that of the 1977 version (S78 addenda) of the code.

For geometric indications the current and planned practice for the ISI Program is to record Max DAC, Wm, MPm and the

[ L dimensions for the particular search unit position whenever the indicated amplitudes equal or exceed 50% DAC. Further, l

descriptive comments are made as to whetler it is a continuous, 360* Intermittent, finger-damped or any ( ther appropriate -

description for the situation.

c. RI-05, RI-08, RI-11 and RI-16 ,

The following words were added to these Relief / Requests 4

for clarification: "A volumetric examination consisting of a radiographic examination was performed during fabrication to meet ASME Section til requirements. These fabrication documents are available for audit at the LaSalle County Station."

d. RI-15 Further clarification was added as follows: "A volumetric

! examination consisting of a radiographic examination was performed during faV.ication to meet ASME Section lli requirements. Thrae fabrication documents are available for audit at the ves el manufacturer."

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e. RI-17 Further clarification was. added as follows: "The pump

, casings are permanently installed in a concrete cavity thus

} making some welds partially or. completely inaccessible for

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volumetric or surface examinations. Those welds-or. portions of welds that are accessible are examined."

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B.J. Youngblood Page Three February 4,1981 3 The RPV closure head nozzle inspection technique was selected based upon considerations of inspection effectiveness and minimal radiation exposure to inspectors. Relief Request RI-09 addresses the need to examine

'the RPV closure (top) head nozzle inside radil (NIR) and nozzle-bore areas using surface techniques rather than volumetric techniques. Dering refueling, the RPV closure head is removed from the vessel and stored in its laydown area on the refueling floor thus permitting easy access for examinations. Approximately 40 man-hours are required to volumetrically inspect the 3 RPV closure head NIR and bore areas. This UT technique employs five specially-contoured variable-angle lucite wedges which track both the radial and circumferential marking lines. By comparison, only four man-hours are required to examine all these areas via PT techniques.

With the equivalent radiation levels, the UT exposure would be ten times the PT exposure for these inspections.

Very truly yours, L.O. De1 George Nuclear Licensing #Aministrator Attachment cc: NRC Resident inspector-LSCS T

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