ML20003A818

Responds to NRC 801030 Ltr Requesting Addl Info Re Util Inservice Insp Program,Clarified in 801117 Meeting.Welds in Class 1 Sys Between Straight Runs of Pipe Which Are Not Structural Discontinuities Will Be Included in Program

ML20003A818
Person / Time
Site:	Oyster Creek
Issue date:	02/05/1981
From:	Finfrock I JERSEY CENTRAL POWER & LIGHT CO.
To:	Crutchfield D Office of Nuclear Reactor Regulation
References
NUDOCS 8102090102
Download: ML20003A818 (11)

Text

% Jzrsey Centrd Power & Ught Company Mad; son Avenue at Punchbowl Road 2 A. fJ~ (-) Mornstown New Jersey 07960 201 539-6111 February 5, 1981

'tr. Dennis M. Crutchfield, Chief Operating Reactors Branch #5 Division of Licensing U.S. Nuclear Regulatory Commission Nashington, D. C. 20555 l

Dear Mr. Crutchfield:

Your October 30, 1980 letter to us contained thirteen (13) questions concerning the Oyster Creek Inservice Inspection l Program. Members of your staff and my staff met on November 17, 1980 to discuss and clarify the thirteen questions and during l

that meeting we agreed to supply you with a written response I to your original questions as clarified during the meeting.

Attached is our response.

If you should have any further questions, please contact Mr. J. Knubel (201-455-8753) of my staff.

1 Very truly yours, 9

l kd#/ ,

Ivan R. Finfr , J.

Vice Preside e la l Attachment l

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8102090\o 49 Jersey Central Power & Lgnt Company is a Member cf the General Puche Ut:hties System

Resconse To NRC Recuest for Additional Information Oyster Creek Nuclear Generating Station ISI Progra: Update

1. NRC Recuest For ASME Code Class 1 piping welds, you ref erence Regulatory Guide 1.46 "Protecticn Against Pipe Whip Inside Containment" as stating the straight runs of piping are not structural discontinuities and, therefore, you interpret Regulatory Guide 1.46 as exempting all straight runs of piping frc= inservice inspection (ISI). This is not an acceptable technical justification. -

Regulatory Guide 1.46 does not address ISI but describes =ethods for pos.;1ating breaks and for determining the =easures that should be taken for physical restraint against pipe whipping that =ay resul:

fro: such breaks. Discuss your degree of conf or:ance with Regulatory Guide 1.46. Provide the technical justification for each Class 1 weld in straight runs of piping that is required to be exa=ined by Section XI but was exe=pted fro exa=ination based on Regulatory Guide 1.46.

Oyster Creek Resconse Request for Relief "R3" will be deleted fro = the Oyster Creek program.

Welds in Class 1 systems between straight runs of pipe which are not structual discontinuities will be included in the Oyster Creek ISI progra=. Ref erence to Regulatory Guide 1.46 will be deleted.

2. NRC Recuest List the Class 1 welds that have been exe=pted from examination l based on IW3-1220(b)(1) of the Code. Proviac calculations and assu=ptions =ade in determining the =axi=u: line size exe=pted. It should be noted that "on-site" power should include only power fro:

the batteries, e=ergency diesels, and the turbine-generator.

Ovster Creek Resconse The Code exe=ption of IW3-1220(b)(1) is not used in the Oyster Creek ISI progra=. Accordingly, this request f or infor=ation is not applicable.

3. NRC Recuest The staf f position c .acerning IWC-1220 exe=ption criteria of Class 2 welds in the e=ergency core cooling syste=, the residual heat re= oval syste=, and contain=ent heat re= oval syste=, as per=itted by the 1974 Edition of See:1on XI, is that a representative sample

- Response to NRC request for additional inf or=ation Page 2 of welds in these syste=s must be subjected to volumetric and/or surf ace examinations during each inspection interval. These safety related systems cannot be completely exempted from volu=etric or surf ace examination based upon the requirements c ; 50.55a(b) in 10 CFR 50, General Design Criteria 36 5 39, and the Su==er 1978 Addenda to the 1977 Edition of Section XI. The ISI program should therefore be revised to include a sampling of welds and the proposed methods of examination for the ICCS, RHRS, and CHRS welds previously exempted for pressure / temperature conditions, line size, or chenistry control.

Class 2 systems other than those ref erenced above may be exe=pted based on operating conditions of pressure or ce=perature in lie.a of design conditions, as permitted by 1977 Edition of Section XI.

Relief will not be granted for components which operate above 275

_ psi or 2000F for short periods of ti=e without a technical justification.

The alternative exa=ination specified in the licensee's ISI program for Class 2 welds exempted under IWC-1220(a) of the Su=mer 1978 Addenda to Section XI should be conducted in accordance with the require =ents of Exa=ination Category C-H, Table IWC-2500-1 in the sa=e Addenda.

Oyster Creek Response 10CFR 50.55a(b) defines the Edition and Addenda of Section XI applicable to the Inservice Inspection Program for Oyster Creek. Specifically, for Class 2 systems the exemption criteria of IWC-1?."3 of the 1974 Edition, Su==er 1975 Addenda are identified as mandatory requirements.

The Oyster Creek ISI program is using the f ollowing two Code exemptions (Note: The exemptions are applied to nondestructive examinations only. All Class 2 systems will be hydrostatically tested in accordance with Code requirements):

IWC-1220(a): " Components in syste=s wh'ere both the design pressure and temperature are equal to or less than 275 psig and 200 F, respectively."

IWC-1220 (d) : "Cemponent contactions, piping, and associated valves, and vessels (and their supports), that are 4 in, nominal pipe size and smaller."

In addition, it should be noted that with the exceptions of the Isolation Condenser and Poison Syste=s all Class 2 systems in Oyster Creek are fabricated from carbon steel; hence, these systems are not sub-ject to IGSCC. The Isolation Coudenser System (performs the essential decay heat removal function) will be nondestructively examined.

The Poison System piping is lh inches nominal pipe size or smaller, is fabricated uring socket welded joints, and will not be nondestructively ,

exa=ined. Our response to your concerns on augmented inservice examinations for the Core Spray and Containment Spray System piping is found in the su= mary for class 2 systems which follows.

Response to NRC request for additional infor=ation page 3 The Class 2 carbon steel systems are all fabricated from STANDARD wall pipe with a wall thickness of 0.375 inches or less. Accordingly, meaningful volumetric examinations using ultrasonic testing techniques are difficult and costly to perform. Surface examination of these velds is not a consideration because it will require extensive weld crown cosmetic grinding and it is not evident what meaningful information would be provided by those examinations. Oyster Creek has completed 10 years of successful com=ercial operation without any unresolved generic' defect-mechanisms being identified for these systems.

In su= mary, the extent of the 151 program for Oyster Creek Class systems is:

System Extent of Examination j - Isolation Condenser -Nondestructive examination.of piping greater 4 than 4 inch NES in accordance with the Code.

-Visual-examination during hydrostatic testing.

- Core Spray (downstream -Nondestructive examination of piping greater of Pumps NZO3-A, 3, than 4 inch NPS in accordance with the Looe.

C, D) -Visual examination during' hydrostatic.

testing.

- Core Spray (upstream -Visual examination during hydrostatic of-Pumps NZO3-A, B, testing-(System is exempted from'non-C, D) destructive examination by IWC-1220(a)).

-Augmented examinations due to NRC concerns, nondestructive examination-of piping' greater i than'4 inch NPS in accordance with the Code.

Since this is a Category.CF item (2 train)-

-13 welds will.be examined in the second-10

. Year Interval (starting December-79). See Note 1. ,

- Containment Spray -Visual examination'during' hydrostatic-testing (System is exempted from non destructive. examination by IWC-1220(a)).

-Augmented examinations due-to NRC concerns, nondestructive-examination'of piping greater than 4 inch.NPS in accordanc~e~with the Code.

'Since this is a CategoryfCF item (2 train) 28 welds will be-examined;in the second 10 Year Interval ~ (starting December 79) . See-Note 1.

Poison : -Visual examination during?hydrostatico l testing (System is' exempted from non-

~

destructive examination by~INC-1220(d)).

NOTE 1: -No reportable findings;for examinations conducted duringethe Interval-(10 years) will result in cancellation"of augmented exxninations.

Response to NRC request for additional information Page 4

- Closed Cooling Water -Visual examination during hydrostatic testing (System is exe=pted from non-destructive examination by IWC-1220(a)).

- Hydraulic Control Unit -Visual examination during hydrostatic testing (System is exe=pted from non-I destructive examination by IWC-1220(d)).

4. NRC Request In Table 3C-2, the licensee requested relief for welds whose physical location within tne plant has linited access. Provide a sketch depicting the inaccessibility or describe the specific conditions which prevent perfor=ance of the Code required examinations. Discuss the seasures necessary to =ake each weld accessible and the hardship this would i= pose, including the estimated radiation exposures to co=plete a specific examination.

To detect potential generic degradation, the size of the examination sa=ple shall be =aintained to the extent practical. The ISI program shculd be revised to include repeated examinations on similar

(=aterial, pipe dia=ecer, and wall thickness) accessible welds with the lowest radiation exposure. The installation of re=ote inspection fixtures should be evaluated to achieve ALARA conditions.

Cyster Creek Response Any requests for relief from nendestructive examination of specific welds due to inaccessibility, high radiation, or other physical limitation or hardship will not decrease the overall inspection sauple size as required by the Code. These welds are identified to the NRC'si= ply as a means to document the inspection problem areas, not to decrease the scope of work.

The Cyster Creek ISI Program will be i=plemented tc the extent practicable considering design, access, and =aterial properties. Limitations to exas-inations including ALARA considerations will be identified in the report /

su==ary of examinations.

5. NRC Request Confirm chat Class 2 pipe to pipe circu=ferential butt welds of the same schedule wall thickness will be examined in the ISI program according to the requirements of Table IWC-2520, Category C-F(b) and C-G(b).

Oyster Creek Response Oyster Creek confirms that the requirements of Table IWC-2520, Category C-F(b) and C-G(b) will be =et. This is identified in the Oyster Creek ISI program exemption "E5".

, additional information Page 5

6. NRC Request The examinations proposed for reactor vessel nozzles are not consistent with the aug=ented examination requirements in NUREG 0619, "BWR Feedwater No::le and Control Rod Drive Return Line No::le Cracking". The augmented examination requirements will be addressed during the implementation of this NUREG. Provide information on the feasibility of performing automated ultrasonic examinations on all of the nozzles to minimize radiation ex-posure.

Ovster Creek Response NUREG-0619 was issued in Draf t form subsequent to the submittal of the Oyster Creek ISI program to the NRC. Consequently, inconsistencies between the two documents would be expected. The Oyster Creek ISI program will be revised as necessary to be in full agreement with the Oyster Creek approved program in.accordance with the final form of NUREG-0619. Oyster Creek reserves the right to re-evaluate augmented examinations after three (3) consecutive annual examinations without reportable findings.

Oyster Creek is considering the use of automated examination equipment as a long term solution to minimize radiation exposure to personnel.

7. NRC Request The Weld Ses=ary Sheets referenced in the licensee's ISI program for various Class 1 and Class 2 welds do not, in all cases define the extent and method of examination.

List the extent and method of examination for each category in Appendices 3A and 3B.

Oyster Creek Response Oyster Creek commits to define the extent and method of examination for all Class 1 and Class 2 categories as identified in Appendices 3A and 3B by April 1981. These changes are part of the current revisions in-process.

The revised program will be~ submitted to NRC.

8. NRC Recuest To maintain the examination sample for the reactor vessel welds,_the examination of accessible vessel welds should be increased, where practical, to maintain the overall length of welds required to be examined by Section XI. . Provide the following additional information concerning the reactor vessel weld examinations:

a) The specific welds for which relief is required.

b) The program currently in use for monitoring radiation damage to

-=aterials in the beltline region.

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Response to NRC request for Pegs 6 additional information c) The feasibilicy of conducting remote visual examinations of welds from the inside surface of the vessel.

d) The design aspects of shielding and insulation which prevent accessibility, if dif ferent from the explanation given for vessel nozzles, i Ovster Creek Respcnse

]

Due to the age of the Oyster Creek design the configuration of the biological shield and reactor vessel make it impossible to examine any of the reactor vessel welds except the following:

- Upper head welds, l

- Vessel to flange circumferential weld, and l - Upper 6 feet of the longitudinal welds in the upper shell.

a) A figure that shows a sketch of the reactor vessel and biological-shield shall be provided by April 1, 1981. All vessel welds for which relief is requested will be numbered.

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b) The current program is iden'tified in Paragraph'4.3.A of the -

Oyster Creek Technical Specifications. A sample rack does exist in the vessel, but is not removable at the present time.

c) The inside of the vessel is clad so that a remote visual examination-will not yield meaningful results. ,,,

d) The inaccessibility for nozzles will be shown on the . sketch' provided -in (a)'.

9. NRC Recuest Surface examinations are.speciiied for the control rod drive housings and integrally welded vessel supports where Section XI specifies either a-surface or volumetric examination. Provide a. sketch of the typical configuration and discuss the reasons that a volumetric.

4 examination is i= practical.

Ovster Creek Response Figure 1 shows the configuration of the weld between the CRD housing and the flange. As can be seen on. Figure 2, due to the machined weld prep on the CRD housing; the. weld crown, and theislope of the flange =

outside wall the UT transducer is physically constrained so that the weld volume'cannot be exa=ined-in full confor=ance with the Code require =ents. Also due to the close proximity of other CRD flanges,-

it is doubtful-that a surface examination of 100% of the weld could be perfor=ed for each weld required to be examined -(i.e. ,10% of the peripheral ~ housings).

additional informstion Page 7 Due to access limisstions and ts an' alternative to Code requirements, Oyster Creek proposes to surface examine 50% of each weld in 20% of the periphral housings. This results in the same length of welds being examined.

The integrally welded reactor vessel support skirt welds are partially accessible for ultrasonic examination.

Oyster Creek will perform the Code required examinations to the extent per=itted by the Oyster Creek ALARA program. Examinations that cannot be perfor=ed as required shall be documented in the appropriate Oyster Creek ISI report /s"--ary of examinations.

10. NRC Recuest

All piping welds within protective structures or guard pipes between containment isolation valves, which cannot meet the augmented.

examination requirements of Section 3.2.d of Branch Technical Position

, APSC3 3-1 in S tandard Review Plan 3.6.1, should be identified in a j relief request.

For the inaccessible weld shown in F2gure 3.1, provide the following infor=ation:

a) The accessibility for volumetric examination of the veld joining l the flued head to the outer sleeve.

b) The proximity of leak detection systems inside cautainment to I these penetrations.

c) The capability of the guard pipe or penetration sleeve to withstand the full dynamic effects of a longitudinal or circumferential break of the enclosed process pipe, includihg jet impingement, pipe whip impact, and < *iror. mental effects.

i Oyster Creek Response i

( a) This weld is not a pressure boundary weld, rather it is a structual-weld and will be visuallyf and surface examined when accessibility.

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permits. Inaccessibility shall be so documented when and if it is j applicable.

I b) The Oyster Creek facility does not have any leak detection system specifically designed. to monitor for leaks in guard pipes. However two systems presently have area temperature monitors to monitor for

! leaks in the general area of these systems. The general; area of these systems does include the containment penetrations. The two systems that do have area temperature monitoring are the Reactor

' Water Cleanup system and Isolation Condenser Systemsjand high' temperatures are alcrmed in the~ control. room. Also as described in t Volume' 1 of the Oyster Creek FDSAR the Oyster Creek plant has an Extensive area radiation monitoring system which will help detect leaks in the sections of piping of .oncern.

l c) This topic is discussed in Amendments 50.and 51 of the Oyster Creek FDSAR.

. additional infor:ation Paga 8

11. NRC Recuest The licensee's ISI program contains a request for relief from volu=etric examination of Class 1 and 2 piping, vessels, and valves of .375 inch thickness and less. Identify the lines and ce=ponents included La this relief request and list their size, thickness, and

=sterial.

4 Oyster Creek Resconse This request for relief will not be applied to Class 1 systems. It will be used with Class 2 systems whose pioing wall thickness.is 0.375 l inches and less. M.ost of the Class 2 thi. "' oipe is exempted from

nondestructive avarination by virtue of its __ ressure and temperature (i.e., by IWC-1220(a)) or its s=all size (i.e., iWC-1220(d)). The only

, portions of Class 2 thin wall pipe for which this request for relief will I be used are the Core Spray System piping between-the-Core Spray Pu=ps NZO3-A, 3, C, D and valves V-20-12 and V-20-18. This piping is all carbon steel with the following characteristics:

Approxi= ate Size Wall Thickness No. of Welds 6 in. 0.280 in. 11 8 in. 0.322 in. 12 10 in. 0.365 in. 74 4

, 12. NRC Recuest The definition of a groi-

• Class 1 valves in"the licensee's program is not in accordance with . diat in Section'XI. Revise the program to include examinations of all code required valves. If the disassembly

of valves solely for inservice inspection is i= practical, a relief request, with technical justification, should be submitted.

i Ovster Creek Response A specific relief request will be included in the next revision of.the Oyster Creek ISI program sub=itted to the NRC. The relief request will identify that all Code required valves will be examined when they are disassembled for =aintenance.

13. NRC Recuest Note 2 in Appendix 33=of the ISI-program states that certain examination.

requirements for pressure retaining bolting havelbeen updated to-those in.the 1977 Edition through the Su=mer 1978 Addenda of the code.~ We will require that all of the require =ents for- bolting in the later edition and addenda, including extent of examination, be =et, if practical.

- WSL3tTV ]

Oyster Creek Response It is Oyster Creek's intent to use all the applicable requirements of later NRC approved editions and addenda when updating to portions of these later Jodes.

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