ML20079G217
| ML20079G217 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 10/01/1991 |
| From: | Piet P COMMONWEALTH EDISON CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM), Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 9110090023 | |
| Download: ML20079G217 (2) | |
Text
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October 1,1991 Oft!ce of Nuclaar Reactor Regulation U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D.C. 20555
Subject:
LaSalle County Station Units 1 and 2 Reactor Pressure Vessel (RPV)0:37 Ahead Examination Program NBC_DocketNoslo-3I'3_arda
References:
(a) R. Stols letter to T.E. Murley dated May 4,1991 (b) W.E. Morgan letter to A.B. Davis dated August 11,1991.
(c) W.E. Morgan letter to U.S. NRC dated January 2,1991.
Dear Sir:
In References (a) and (b), Commonwealth Edison (CECO) committed to review the fabrication contract variations for both the LaSalle Unit 1 and Unit 2 Reactor Pressure Vessel to support the development of an inspection plan. An inspection plan for LaSalle Unit 1 was submitted to the NRC Staff in Relerence (c). The Reierence (c) inspect!on plan was submitted for your staff's review and was performed during the February 1991 refueling outage for Unit 1 (L1R04). The attachment to this letter provides an inspection ith the upcoming outage plan to be implemented every other refueling outage beginning w(October 1992, L1R05).
for Unit 2 (January 1992, L2R04) and the next outage for Unit 1 If there are any questions regarding this subject, please contact this office.
Sincerely,
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Peter L. Piet Nuclear Licensin9 Administrator Attachment cc:
A.B. Davia - Regional Administrator - Rlli B.L. Siegel - Project Marager - NRR Senior Resident inspector - LaScIle Office of Nuclear Facility Safety - IDNS
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o ATIACHMENI REACTOR PRESSURE VESSEL HEAD EXAMINATION PROGRAM LASALLE UNITS 1 AND 2 BACKGROUND The following on-going examination program for the RPV head at LaSalle Units 1 and 2 has been implemented due to concerns with stress corrosion cracking in the low alloy
-base material. Since the discovery of the clad cracking on the Quad Cities Unit 2 RPV head in 1990, the RPV head cladding has isen previously examined once at LaSalle Units 1 and 2 and no cracks were detected. The following examination program does not include the RPV upper shell-to flange weld because no major mismatches have be9n identified in this weld.
rdSEECIJORMEIHOD 1.
Visually examine (VT-3) 100% of the inside surface of the RPV head. Lighting adequacy will be verified with a 1/32 inch black line on a 18% neutral gray card.
Conditions to be examined for and recorded:
- a. Cracks
- b. Linearindications
- c. Heavy / unusual rust streaks 2.
Dye 3enetrant test (DPT) all recordable indications found by activities listed in item No. ' above.
3.
Size all cracks identified by item No. 2 above by ultrasonic testing (UT), from the inside surface of the RPV head. The enhanced UT technique (45*,1 Mhz shear wave) from the outside surface may be used to supplement the results of the UT from the ID (inside diameter).
Any apparent flaws or deviations la the RPV head identified by this activity shall be evaluated by CECO's Engineering Department prior to Unit startup.
INSEEGIlON.EBEQUENOX The inspection plan outlined above will be implemented avery other ietueling outage for both LaSalle Unit 1 and LaSalle Unit 2. This test frequency shall be initiated for L2R04 (January 1992) and L1R05 (October 1992). The planned inspection frequency satisfies the requirements of ASME Section XI.
. ch/1204/2
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