ML20078E606

Transmits Results of Last ASME Section XI ISI of Plant Unit 1 RHR Nozzle to Vessel Welds,Per 950120 Request

ML20078E606
Person / Time
Site:	Braidwood
Issue date:	01/23/1995
From:	Pontious H COMMONWEALTH EDISON CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM), Office of Nuclear Reactor Regulation
References
NUDOCS 9502010046
Download: ML20078E606 (5)

Text

=

, -.,. f^'s I

Commonwealth Edison e ) ~ 1400 Opus PI:cs

(~ Downers Grove, innois 60515 January 23,1995 Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Washington, D.C. 20555 Attention: Document Control Desk

Subject:

Braidwood Nuclear Power Station, Unit 1 Residual Heat Removal (RHR) Heat Exchanger (HX) Nozzle to Vessel Welds Inservice Inspection Results NEC Docket No. STN 50-456

References:

1. Teleconference between Commonwealth Edison Company (Comed) and the Nuclear Regulatory Commission (NRC) held on January 20,1995 regarding Byron and Braidwood Stations, Units 1 and 2, RHR HX Nozzle to Vessel Weld Inservice Inspections

2. Robert M. Pulsifer (NRC) letter to Thomas J. Kovach (Comed) dated November 21,1991 transmitting the Safety Evaluation Report (SER) for the Braidwood Station, Unit 2, RHR HX Nozzle to Vessel Welds Fracture Mechanics Analysis The purpose of this letter is to transmit the results of the last ASME Section XI Inservice Inspection of the Braidwood Unit 1 RHR HX Nozzle to Vessel Welds as requested in Reference 1. These inspections were conducted during the Braidwood Unit 1 Cycle 3 Refuel Outage (AIR 03) which began September 5,1992, and concluded November 3,1992.

During these inspections, ultrasonic reflectors greater than those allowable by ASME Section XI Subarticle IWB-3'iOO were detected. These indications were subsequently evaluated using fracture mechanics analysis performed in accordance with ASME Section XI Subarticle IWB-3600 and determined to be acceptable. The fracture mechanics analysis thtt was used is documented in Westinghouse Letter Report MMDT-SMT-062(92), " Fracture Mechanics Evaluation Byron and Braidwood Units 1 and 2 Residual Heat Exchanger Tube Side Inlet and Outlet Nozzles." The methodology outlined in this report has been previously reviewed and approved by the Staff (See Reference 2).

9502010046 950123 PDR ADOCK 05000456

% 10 C.;0

[

P PDR

/l ll D

9},

t NRC Document Control Desk 2- January 23,1995 ,

As shown in the attachment, all indications fall within ASME Section XI l acceptance standards in' Subarticles IWB-3500 and IWB-3600. i

'I Please address any further comments or questions regarding this matter to this office.

g .

Sincerely,  !

1 i

Harold D. Pon_tims, Jr. -

Nuclear Licensing Administrator Attachment

]

I' cc: J. B. Martin, Regional Administrator. Region III S. G. DuPont, Senior Resident Inspector - Braidwood R. R. Assa, Braidwood Project Manager - NRR Oflice of Nuclanr Facility Safety - IDNS -

k 6

I l

1 a

I

.(

ATTACHMENT INDICATION

SUMMARY

Component: 1RH02AA Weld No: 1RHXN-1 Outlet Nozzle A total of 10 indications above 50% DAC were recorded with 2 of these indications exceeding 100% DAC with definable length.

The following is a summary ofindications which exceed 100% DAC and exhibit a definable depth and length as reported in Ebasco ultrasonic report number 92BR1-UT-057:

1 Ind. Loc. Max. Amp. Lgth, o *

• a/l a/t*

3 8.64-10.56" 141 % 1.92" .120" .062" 30.0 %

8 30.77-31.09" 126 % .32" .120" .375" 30.0 %

i a/t represents through wall percentages ofindication utilizing the nozzle wall thickness (.400").

Denotes ASME Section XI (Article IWA-3000) characterization (i.e.

a= surface, 2a= subsurface).

Identified flaws were characterized as surface flaws per Table IWB 3514-2.

1 I

)

I

~

ATTACHMENT (Continued)

Component: 1RH02AA Weld No: 1RHXN-2 Inlet Nozzle A total of 16 indications above 50% DAC were recorded with 4 of these indications exceeding 100% DAC with definable length. .

The following is a summary ofindications which exceed 100% DAC and exhibit a definable depth and length as reported in Ebasco ultrasonic report number 92BR1-UT-058:

Ind. Loc. Max. Amp. Lgth. a** a/l a/t*

3 9.36- 9.80" 112 % .44" .150" .341" 37.5%

12 30.10-31.45" 158% 1.35" .094" .070" 23.5 %

15 38.53-39.10" 126 % .57" .130" .228" 32.5%

i 16 41.01-42.02" 112 % 1.01" .094" .093" 23.5 %

a/t represents through wall percentages ofindication utilizing the nozzle wall thickness (.400").

Denotes ASME Section XI (Article IWA-3000) characterization (i.e.

a= surface, 2a= subsurface). '

Identified flaws were characterized as surface flaws per Table IWB 3514-2.

,g. <-

.- ATTACHMENT (Continued)

Component: 1RH02AB Weld No: 1RHXN-1 Outlet Nozzle No indications above 50% DAC were recorded as rept ted in Ebasco ultrasonic report number 92BR1-UT-059.

Component: 1RH02AB Weld No: 1RHXN-2 Inlet Nozzle A total of 5 indications above 50% DAC were recorded with none of these indications exceeding 100% DAC with de5nable length as reported in Ebasco ultrasonic report number 92BR1-UT-060.

l l

I l

I