ML20024F085
| ML20024F085 | |
| Person / Time | |
|---|---|
| Site: | Byron  |
| Issue date: | 08/26/1983 |
| From: | Tramm T COMMONWEALTH EDISON CO. |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| 7206N, NUDOCS 8309080210 | |
| Download: ML20024F085 (19) | |
Text
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) 'Uommonwealth Edison t!'
O one First National Plaza, Ctucago tilinois v
Address Reply to: Post Office Box 767 Chicago. Illinois 60690 August 26, 1983 4
i Mr. Harold R. Denton, Director Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, DC 20555
[
Subject:
Byron Generating Station Unit 1 Preservice Inspection Program Plan NRC Docket No. 50-454 Reference (a):
March 1, 1983, letter from T. R.
Tramm,to H. R. Denton.
Dear Mr. Denton:
This is to provide copies of preservice inspection relief requests for Byron 1.
These requests are to be included with the other requests submitted with reference (a) as Appendix B to the Preservice Inspection Program Plan.
Enclosed _are relief requests NR-3 (Rev. 0), NR-4 (Rev. 0),
and NR-8 (Rev 0).concerning volumetric examination of cast stainless steel welds.
Justification for each request is provided in these documents.
Please address questions regarding this matter to this One signed original and fifteen copies of this letter and the-enclosures are provided for your review.
Very truly yours, T. R.
Tramm Nuclear Licensing Administrator 1m-h00 Enclosures tg 8309080210 830826
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PDR ADUCX 05000454 G
PDR 7206N A
NR-3 R
Rsv. O RELIEF REQUEST NR-3 1.
SYSTEM: Reactor Coolant 2.
NUMBER OF ITEMS:
8 Cast Stainless Steel SA-351-CF8A (Elbow) to Cast Stainless Steel SA-351-CF8 (Pump)
Line Number Weld Number Attachment Numbers 1RC02 AA-31" J-8 1&2 LRC02AB-31" J-8 1&2 1RCO2AC-31 J-8 1&2 1RC02AD-31 J-8 1&2 Cast Stainless Steel SA-351-CF8A (Elbow) to Cast Stainless Steel SA-351-CFCM (Valve)
Line Number Weld Number Attachment Numbers 1RC01AA-29" J-4 1&3 1RC01AB-29" J-4 1&3 1RC01AC-29" J-4 1&3 1RC01AD-29" J-5 1&3 3,
ASM5 CODE CLASS:
1 4.
ASME CODE SECTION XI REQUIREMENTS: Table IWB-2500-1, Examination Category B-J, Item B.9.11 requires a surface and volumetet- %v2mination of the regions described in Figure IWB-2500-8 for piping 4 in nominal pipe size and greater.
In addition, Examination Category B-P, Item B15.50 requires a system leakage test in accordance with IWB-5221 each refueling outage for all pressure retaining components. Article IWB-2200, "Preservice Examination" states that:
NR-3 Rsv. 0 Examinations required by this Article shall be completed prior to a.
initial plant startup.
In addition, the preservice examinations shall be extended to include essentially 100% of the pressure re+taining welds in all Class 1 components except in those components exempted from examination by IWB-1220 (a), (b), or (c).
b.
Shop and field examinations may serve in lieu of the on-site preservice examination provided:
1).
In the case of' vessels only, the examination is performed af ter the hydrostatic test required by Section III has been completed; 2).
such examinations are conducted under conditions and with equipment and techniques equivalent to those that are expected to be employed for subsequent inservice inspections; 3).
the shop and field examinations records are, or can be, documented and identified in a form consistent with those required in IWA-6000.
5.
BASIS FOR RELIEF:
All of the welds listed above are cast austenitic stainless steel to cast austenitic stainless steel. At this time we have completed acceptable radiographic examinations of these welds to. meet the preservice volumetric requirement. However, we do not intend to use radiography as our inservice volumetric examination method. Attempts have been made to ultrasonicly examine these welds without success.
Harrisonics Laboratory, a design and manufacturing firm for ultrasonic search units, was sent a piece of SA-351-CF8 material with a side drilled hole and rectangular notch and was requested to design a special transducer that could adequately resolve these two reflectors, see Attachment 4 for block arrangement.
Af ter six months of effort, Harrisonics reported that they failed to find any combination of search unit parameters that would penetrate the material more than 1/2 to 3/4 of an inch of metal path with _
NR-3 Rey, o a use ful signal-to-noise ratio. The transducer which provided this penetration was a dual element, refracted "L" wave, 45' focused transducer with the focal point at 2.5",
the nominal thickness of the welds in question.
6.
ALTERNATE TEST METHOD:
None.
7.
JUSTIFICATION:
The welds listed above are joining SA-351-CF8A (elbow) to either SA-351-CF8 (pump casing) or SA-351-CF8M (valve body). These materials have very poor acoustic properties which do not lend themselves to ultrasonic examination.
Presently, conventional radiography is not a viable inservice examination as the background radiation will increase over the course of plant life.
This increase in radiation will likely cause the film tc fog which will reduce the resolution of any defects.
At this time, EPRI's MINAC, the portable high energy x-ray source, has not been demonstrated as a viable alternative in examining these welds.
Typical concerns include the MINAC's size and mobility in the areas in which these scids are located. The MINAC's development will be followed and when it is determined that it can be used to examine these welds with good quality radiograp as, it will be given further consideration.
In that cast austenitic stainless steels are extremely tough and resistant to intergranular stress corrosion cracking, leakage long before complete failure is virtually certain. Leakage within the Reactor Coolant System is checked each re fueling outage.
In addition to this leakage test, leakage within the containment will be monitored by two (2) remote methods.
First, leakage from within the containment will flow into the weir box of the containment sump.
3 NR-3 Rav. O Within this weir box there is a capacitance type level indicator capable of detecting a 2 gallon per minute leak within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />.
In addition to the level indicator there are sump pump-run-time totalizers which measure pump-run time.
The second method utilizes a containment radiation monitoring system capabic of detecting a 1 gallon per minute leek within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />. Additional l
atmospheric monitoring is provided by pressure, temperature, and humidity monitors.
All atmospheric monitors are monitored in the main control room, t
By use of the above mentioned leakage detection systems and the high resistance of cast austenitic stainless steel to stress corrosion cracking, an high level of structural integrity for these welds will be assured.
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_.=. I-NR-4 I Rev. O i e RELIEF REQUEST NR-4 1. SYSTEM: Reactor Coolant 2. NUMBER OF ITEMS: 8 4 Cast Stainless Steel SA-351-CF8A(Elbow) to Cast Carbon Steel SA-216 CR-WCC (Nozzle) Line Number Weld Number Attachment Numbers 1RC01AA-29" F-2 1&2 1RC02AA-31" F-1 1&2 4 1RC01AB-29" F-2 1&2 LRC02AB-31" F-1 1&2 1RC01AC-29" F-2 1&2 1RC02AC-31" F-1 1&2 + i j 1RC01AD-29" F-2 1&2 1RC02AD-31" F-1 1&2 3. ASME CODE CLASS: 1 4. ASME CODE SECTION XI REQUIREMENTS: Table IWB-2500-1, Examination Category B-F, Item B5.30 requires surface and volumetric examination of the regions described in Figure IWB-2500-8 for all Steam Generator nozzle-to-safe end welds. In addition, Examination Category B-P, Item B15.30 requires a system leakage test in accordance with IWB-5221 each refueling outage for i the Steam Generator pressure retaining boundary. Article IWB-2200, "Preservice Examination", states that: Examinations required by this Article shall be completed prior to a. initial plant startup. In addition, the preservice examinations shall be extended to include essentially 100% of the pressure retaining welds in all Class I components except in those components exempted from examination by IWB-1220 (a), (b), or (c). ,,,.-,,.n-. w,- ,,m n. r -n--,- ,n---- -v--
( NR-4 + Rev. O b. Shop and field examinations may serve in lieu of on-site preservice examinations provided: 1). In the case of vessels only, the examination is performed af ter the hydrostatic test required by Section III ! as been completed; 2), such examinations are conducted under conditions and with equipment and techniques equivalent to those that are to be employed for subsequent inservice inspections; 3). the shop and field examination records are, or can be, documented and identified in a form consistent with those required in IWA-6000. Ultrasonic examination requirements from Mendatory Appendix III, Article III-4000, require examination for: a. Reflectors parallel to the weld seam. The angle beam examination for reflectors parallel to the weld seam shall be performed by a full V path from one side or a one-half V path from two sides of the weld, where practicable. b. Reflectors transverse to the weld seam. 1). The angle beam examination for reflectors transverse to the weld seam shall be performed on the weld crown on a single scan path to examine the weld root by one-half V path in two directions along the weld. 2). For inservice examination, only those welds showing reportable preservice indications need be examined for transverse re flectors. 5. BASIS FOR RELIEF: The welds listed above are cast austenitic stainless steel SA-351-CF8A to cast carbon steel SA-216 GR-WCC with austenitic stainless steel cladding. We have completed acceptable radiographic and surface i examinations to meet the preservice volumetric and surface requirements.
~. ~ NR-4 Rev. 0 In addition, ultrasonic examinations were performed circumferential1y in both directions for transverse reflectors, and axially from the steam i generator nozzle side for parallel reflectors with a one-half V path Nhither the circumferential or axial scan located any rejectable scan. 1 indications. The one-half V path examination from the elbow side of the weld could not be performed due to the poor acoustic properties of the cast austenitic stainless steel. i i 6. ALTERNATE TEST METHOD: None. 7. JUSTIFICATION: A high level of Structural integrity has been assured for the noted welds over the life of the plant by: a). Having performed an acceptable one-sided ultrasonic examination. b). Having performed acceptable radiographic and surface examinations, and 4 i c). Having the leakage detection system described in NR-3. l t 1 l l l l 1 l I . --- ~~. - - - - - - - - - - ~ - - ' - - - + - - ' - - * * - - - ~ ~ ~ ~ '
i LOOP 2 } 7ocp 3 1 1 CO?AC-317 1RCO!BB l l 'RC018C REACTCR / 1 Fi" Ft b, \\ $0LANT' {l F2 F2 I PUMP ' Y D: CAL COLD LEG O A A N4 ) o m e v'O STEAM oENERATOR e i \\ / ( i ) n REACTOR ) 1 U JOOLANT i 1RC01R l i FJMP 1 l l .[ g y d g f TvoiCAL CRos50VER LEG .h STEAM ' i s 4 GENERATOR / t .i 5l FI FI ~. i ll REACTOR 1RC 018A ) l 1RC01BO l TYPICAL HOT LEG ~1RC02A A-3T 1RCO2AD 3f l LOOP 1 LOOP 4 ATTACHMENT 1 o' NR-4
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STEAM / GENERATOR / / /' NOZZLE / / ELBOW s. N s N SEE DETAll DELOW 7 s. ~~ ELBOW TO NOZZLE CAST STEAM GENERATOR NOZZLE WELD CLADblNG CAST EL90W N z s WELD DETAll A T TAC HMENT 2 NR-4 L
p a NR-8 Ray. O RELIEF REQUEST NR-8 1. SYSTEM: Reactor Coolant 1 2. NUMBER OF ITEMS: 4 Cast Stainless Steel SA-351-CF8A (Elbow) to Stainless Steel SA-182 CR-F316 (Safe-end) Line Number Weld Number Attachment Number 1RC03AA-27.5" J-11 1&2 DRC03AB-27.5" J-10 1&2 1RC03AC-27.5" J-12 1&2 DRC03AD-27.5" J-10 1&2 3. ASME CODE CLASS: 1 4. ASME CODE SECTION XI REOUIREMENTS: Table IWB-2500-1, Examination Category B-J, Item B9.11 requires surface and volumetric examination of the regions described in Figure IWB-2500-8 for piping 4 in. nominal pipe size and greater. In addition, Examination Category B-P, Item B15.50 requires a leakage test in accordance with IWB-5221 each refueling outage for all pressure retaining components. Article IWB-2200 "Preservice Examination" states that: Examinations required by this Article shall be completed prior to a. initial plant startup. In addition, the preservice examinations 4 shall be extended to include essentially 100% of the pressure retaining welds in all Class 1 components except in those components exempted from examination by IWB-1220 (a), (b), or (c). b. Shop and field examinations may serve in lieu of on-site preservice examination provided: 1). In the case of vessels only, the examination is performed af ter the hydrostatic test required by Section III has been completed;.. -,. -
- ~. _ = ~ Y-NR-8 Rev. O 2). such examinations are conducted under conditicas and with equipment and techniques equivalent to those that are expected to be employed for subsequent inservice inspections; i 3). the shop and field examination records are, or can be, documented and identified in a form consistent with those required in IWA-6000. Ultrasonic examination requirements from Mandatory Appendix III, Article 111-4000, require examination for: a. reflectors parallel to the weld seam. The angle beam examination for reflectors parallel to the weld seam shall be performed by a full V path from one side or a one-half V path from two sides of the weld, where practicable. o b. reflectors transverse to the weld seam. 1). The angle beam examination for reflectors transverse to the weld seam shall be performed on the weld crown on a single scan path to examine the weld root by one-half V path in two dhuctions along the weld. 2). For inservice examination, only those welds showing reportable preservice indications need be examined for transverse reflectors. 5. BASIS FOR RELIEF: The welds listed above are all cast austenitic stainless steel to Reactor Vessel nozzle safe-ends. These welds have received radio-graphic and surface examinations to meet the preservice volumetric and surface examination requirements. In addition, ultrasonic examinationr. were performed circumferentially in both directions for transveiaa reflectors, and axially from the safe-end side only for parallel reflectors. The axial scan from the elbow was not performed due to the poor acoustic properties i of cast austenitic stainless steel. i l - - - - - ~ ~ - - - - - ' ' ~ " - " - ~ ~
NR-8 Rev. 0 6. ALTERNATE TEST METHOD: hace. i 7. JUSTIFICATION: A high level of structural integrity has been assured for the noted welds over the life of the plant by: a). Having performed an acceptable one-sided ultrasonic examination. b). Having performed acceptable radiographic and surface examinations, and c). Having the leakage detection system described in NR-3. E ) i 3 i 4 i t l- . 4 .,e,. y - ,._.._,.m.. ,..._....<<,,. ~ _ - . _ _.. -. ~, _,_,,,,-,-.......-..,-,v-,-,,,
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