ML20080D515

Discovery 12,consisting of Answers to Third & Final Set of Interrogatories

ML20080D515
Person / Time
Site:	Limerick
Issue date:	08/26/1983
From:	PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	Lewis M LEWIS, M.
Shared Package
ML20080D510	List: ML20080D509 ML20080D515
References
NUDOCS 8308300477
Download: ML20080D515 (14)

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In the Matter of )

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Philadelphia Electric Company ) Docket Nos. 50-352

) 50-353 (Limerick Generating Station )

Units 1 and 2) )

APPLICANT'S ANSWERS TO INTERVENOR LEWIS'S THIRD AND FINAL SET OF INTERROGATORIES TO THE NRC STAFF AND LICENSEE DISCOVERY 12 AUGUST 26, 1983 8308300477 030826

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Interrogatory No. 1 For the Licensee: Please answer the two questions in Interrogatory 1. You need not refer to the NRC or the GE document in in anwer (sic). Please refer to subscript a of your answer to Interrogatory No. 2 at page 3 your Discovery 8 June 13, 1983.

Are there any set of conditions wherein a BWR can experience the simultaneous rapid cooling and high pressure necessary to create a significant PTS?

Further, can a BWR experience a cooling (rapid or not) which will produce significance (sic) stresses at temperatures close to RTndt in any temperature -pressure boundary? Please answer above two questions regarding any set of conditions that can produce a '

PTS in a BWR.

Answer l

Pressure in the boiling water reactor follows the steam saturation curve. For all cold water injection events, the reactor becomes depressurized before significant quantities of cold water can be injected to quench the vessel. The injected water is simultaneously mixed with vessel inventory to moderate temperature gradients at the vessel walls. Thus, within the BWR design basis, the simultaneous combination of high pressure and i rapid cooling necessary for PTS will not occur.

The BWR does not experience cooling which will introduce significant stresses in the vessel at temperatures close to the RTndt.

1 Participants in Preparation of Answer Sampath Ranganath i

Manager, Mechanics Analysis General Electric Company 175 Curtner Avenue San Jose, CA 95125 2

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t John S. Kemper Vice President - Engineering & Research Philadelphia Electric Company 2301 Market Street Philadelphia, PA 19101 l

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t Interrogatory No. 2 Documents (sic) request: To the Licensee: In discovery 8 ,you refer to several documents given out as previously provided as Discovery 2 , Enclosure 3, Item 1 and 2,3,1; and 2,3,5. Can you give the date and title of the cover letter. I can not find them. Please check if they were sent to me.

Answer Several documents referred to in " Applicant's Answers to Intervenor Lewis's First Set of Interrogatories on PTS Contention", Discovery 8, June 13, 1983 were previously made available in response to informal discovery requests made by Mr.

Frank R. Romano in his September 3, 1982 letter to Troy B.

Conner, Jr., counsel for the Applicant. Enclosure 3 to that letter requested documents related to pressurized thermal shock.

As indicated in the January 11, 1983 letter from Mark. J.

Wetterhahn, counsel for the Applicant, to Mr. Romano, the requested documents were designated Discovery 2, Enclosure 3, Items 1-5, and made available for inspection and copying. These documents were not sent to Mr. Romano or to Mr. Lewis.

Participants in Preparation of Answer H. David Honan Licensing Engineer Philadelphia Electric Company 2301 Market Street Philadelphia, PA 19101 John S. Kemper Vice President - Engineering & Research Philadelphia Electric Company 2301 Market Street Philadelphia, PA 19101 4

s Interrogatory No. 3

To both the Licensee and staf f:Recently the NRC releases (sic) an order concerning the ongoing IGSCC in BWRs. I have attempted to get further information on this without success.

Therefore , I am submitting the following interrogatory on the relationship of IGSCC to PTS in BWRs.

Are any structures which receive neutron irradiation subject to IGSCC? Discuss the feedwater nozzle and piping as mentioned on page 5.3-7 of the LGS FSAR , Para. 5.3.1.5.3.

a. Has all "new" information on unresolved safety issues been factored into the PTS problem as the information has become available?

b. Have all synergistic or cumulative effects from other USI been factored into the PTS problem and its consideration by the Licensee and NRC staff? Give specific examples. Discuss USI of

" cold overpressurization" in your answer.

c. Are there any other concerns not covered in the USI which can or do have an effect on the consideration of PTS been considered

, adecuately at LGS? Discuss measurement of neutron flux ( PECo Boyer to Eisenhut , April 15,1983, Page 4, last paragraph) and difficulties of ultrasonic testing (MU: Schwencer to PECo Bauer ,

4 June 3,1983, MEB enclosure Page 250-8 Paragraph 250.4 and 250.3 4

.A.)

Answer Intergranular stress corrosion cracking (IGSCC) has been j observed in boiling water reactors only in components fabricated of sensitized austenitic stainless steels. The Limerick reactor pressure vessels are fabricated of ferritic steel and are a

therefore not susceptible to IGSCC. The feedwater nozzle and j

piping are also fabricated of ferritic materials and are not susceptible to IGSCC.

a. Since PTS is not a problem for BWRs, the impact of other

" unresolved safety issues" on PTS is not relevant to the BWR.

b. See response to a., above.

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I The Applicant is not aware of an unresolved generic safety issue on " cold overpressurization".

c. See response to a., above.

The neutron monitoring system discussed on page 4 of the April 15, 1983 letter from V. S. Boyer to D. G. Eisenhut provides -

information to control room operators for purposes of reactivity control, as required by Regulatory Guide 1.97. It is unrelated a to any PTS-related concern.

I The June 3, 1983 letter from A. Schwencer to E. G. Bauer, Jr.

1 transmitted, inter alia, NRC staff request for additioncl information numbers 250.3 and 240.4. Responses to these requests were provided in Revision 21 to the FSAR, June, 1983 (designated Discovery 12, Item 3c).

Participants in Preparation of Answer i

Sampath Ranganath 1

Manager, Mechanics Analysis General Electric Company 175 Curtner Avenue San Jose, CA 95125 John S. Kemper Vice President - Engineering & Research Philadelphia Electric Company

, 2301 Market Street l

_ Philadelphia, PA 19101 H. David Honan Licensing Engineer

) Philadelphia Electric Company 2301 Market Street Philadelphia, PA 19101 1

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Interrogatory No. 6 To licensee: See LGS FSAR Figure 4.3-29. Is the shroud i shown in Figure 4.3-29 continuous? Are there areas where the vessel wall is not shrouded from the core? Specify all such areas. Specify neutron flux for unshrouded areas.

Answer

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I The shroud is continuous.

! Participants in Preparation of Answer t

! Lloyd S. Burns Principal Engineer, Radiological Analyses General Electric Company 175 Curtner Avenue San Jose, CA 95125 i

John S. Kemper Vice President - Engineering & Research Philadelphia Electric Company i 2301 Market Street i

Philadelphia, PA 19101 4

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I Interrogatory No. 7 To the licensee and staff; In my Interrogatory 6 of my first set of Interrogatories I was looking for an (sic) yes or no answer. Please provide an (sic) yes or no answer to the following repeat interrogatory.

Have any " test coupons" of affected materials been irradiated and tested from BWRs of design similar to Limerick?

Answer i

Yes. The results of radiation effects on pressure vessel steel are documented in NEDO-21708, " Radiation Effects in Boiling

Water Reactor Pressure Vessel Steels" (previously provided as i

l Discovery 8, Item 10).

Participants in Preparation of Answer i Sampath Ranganath Manager, Mechanics Analysis General Electric Company 175 Curtner Avenue San Jose, CA 95125 i John S. Kemper l Vice President - Engineering & Research Philadelphia Electric Company 2301 Market Street Philadelphia, PA 19101 l

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.' 1 COMMONWEALTH OF PENNSYLVANIA  :

ss.

• COUNTY OF PHILADELPHIA  :

l J. S. Kemper, being first sworn, deposes and states:

That he is Vice President of Philadelphia Electric Company, the Applicant herein; that he has read the foregoing Applicant's Answers to Intervenor Lewis 's Third and Final Set of Interrogatories to the NRC Staff and Licensee and knows the l contents thereof; and that the statements and matters set forth therein are true and correct to the best of his knowledge, l information and belief.

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MD S. H I pfce Presid6nt Subscribed and sworn to before me this 51 day of August, 1983 M -

cdell Notary Pub'lic PATRICIA D. SCHott ifotary Put:1.c. Philadsiphia, Phstads!;,hia Co.

My Commission Empres Ichtuary 10.1986

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LGS FSAR DUESTION 250.3 I. Sections 5.2.4 and 6.6 of the Limerick Generating Station FSAR and the partial PSI Program (Rev. 5), submitted with a letter dated September 24, 1982, reference ASME Code Section XI, Appendix III of the Winter 1975 Addenda and Paragraph IWA-2232 of the Summer 1976 Addenda which has not been referenced in 10CFR50.55a(b). Note that 10CFR50.55a(b) states that when applying the 1974 ASME Section XI Code Edition, only the Addenda through Summer 1975 may be used. If Appendix III is used it must be used in conjunction with Summer 1978 Addenda or later Addenda as referenced by 10CFR50.55a(b). Plant specific approval has

, been granted to use. Appendix III of the Winter 1975 Addenda if the Applicant demonstrates that the provisions used are equivalent or superior to the requirements of referenced editions of Section XI Code.

II. In later editions of the ASME Code, Appendix III of Section XI, is specified for ferritic piping welds. If this requirement is not applicable (for example, for austenitic piping welds), ultrasonic examination is required to be coriucted in accordance with the applicable requirements of Article 5 of Section V, as amended by IWA-2232. Discuss the criteria for applying Article 5 of ,

Section V, as amended by IWA-2232. Provide a technical justification for any alternatives used such asSection XI, Appendix III, Supplement 7, for austenitic piping welds and discuss the following:

A. All modifications permitted by Supplement 7.

B. Methods of ensuring adequate examination sensitivity over the required examination volume.

C. Methods of qualifying the procedure for examination through the weld (if complete examination is to be

' considered for examinations conducted with only one side access)

III. When using Appendix III of Section XI for preservice or inservice examination of either ferritic or austenitic piping welds the following should be incorporated

A. Any crack-like indication, 20% of DAC or greater, discovered during examination of. piping welds or adjacent base metal materials should be recorded and investigated by a Level II or Level III examiner to the extent necessary to determine the shape, identity, and location of the reflector.

250.3-1 Rev. 21, 06/83

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LGS FSAR B. The Owner should evaluate and take corrective action h for the disposition of.any indication investigated and found to be other than geometrical or metallurgical in nature.

RESPONSE

I. At the time the Limerick PSI program commenced, the latest edition of the code permissible for use was the Summer 1975 Addenda. In an effort to take advantage of improved UT methods, Appendix III of the Winter 1975 Addenda and Paragraph IWA-2232 of the Summer 1976 Addenda were used.

Although these items are not specifically referenced by 10CFR50.55a(b), they are equivalent to the comparable portions of the subsequently approved by 10CFR50.55a (b) ASME Section XI of Summer 1978 Addenda as long asSection XI Appendix III indications greater than 50% DAC are recorded. The Limerick ISI procedures do record such indications.

II. Supplement 7 of Appendix III permits the use of Appendix III for austenitic piping welds with certain modifications. It is our position, consistent with the PSI /ISI industry, that Appendix III (at 50% DAC recording) is more appropriate for austenitic piping weld examination than Article 5 of ASME

Section V.

The NRC has previously accepted this position for Susquehanna, Diablo Canyon, and other nuclear power plants.

Thus for austenitic piping welds:

A. All of the. Supplement 7 modifications are being used.

B. Examination sensitiv'ity is ensured through the calibration process.

C. Where one-sided-access only occurs and penetrations cannot be confirmed, a one-sided-access limitation is noted in the data package for that weld. -

III. Whe'n using Section XI, Appendix Ii1 for either ferritic or austenitic piping welds, the following applies:

A. All indications showing signal amplitudes equal to or in excess of 20% of the reference response are evaluated to the extent that the level II or III examiner can determine their true nature.

B. The owner evaluates and takes corrective action for the disposition of any indication investicated and &

found to be other than geometrical or metallurgical in W nature.

Rev. 21, 06/83 250.3-2

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LGS FSAR corrective action is implemented and the subject weld is reexamined.

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l 250.3-3 Rev. 21, 06/83

LGS FSAR OUESTION 250.4

1. Clarify the discrepancy between Limerick FSAR Section 3.6.2.6 which states that " guard pipe assemblies are not used in this plant" and Sectien 6.6.8 Augmented Inservice Inspection to

, Protect Against Postulated Piping Failures, paragraph (c) which states " Inspection ports are provided in guard pipes to permit examination of circumferential pipe welds."

High energy lines within the " break exclusion" of the containment penetration area, whether encased in guard pipes or not, must receive augmented preservice/ inservice examination regardless of the requirements of Section XI of the ASME Code as discussed in SRP 3.6.1 and 3.6.2. However, high energy lines meeting the " modified break exclusion region" criteria need not be subjected to augmented preservice/ inservice examination. The " modified break exclusion region" criteria may be applied in those special cases in which guard pipes are necessary, and it has been demonstrated to the satisfaction of the NRC that access to perform an examination is extremely difficult to achieve. In

, such areas the examination requirements may be eliminated provided the guard pipe is designed for the full dynamic effects of a longitudinal or circumferential break of the .

enclosed process pipe including jet impingement, pipe whip impact and environmental effects. ~

If the high energy fluid system piping does not meet the

" modified break exclusion region" criteria, submit the

required augmented preservice/ inservice examination program for this piping.

2. Confirm that high energy fluid system piping between containment isolation valves will receive an augmented examination as follows:

A. Protective measures, structures, and guard pipes should not prevent the access required to conduct the inservice examination specified in the ASME Code,Section XI.

B. For those portions of high energy fluid sys, tem piping between containment isolation valves, the extent of inservice examination completed during'each inspection interval (ASME Code Section XI) should provide 100%

volumetric examination.of circumferential and longitudinal pipe welds within the boundary of these portions of piping.

C. For those portions of high energy fluid system piping enclosed in guard pipes, inspection ports should be

, provided in the guard pipes to permit the required 250.4-1 Rev. 21, 06/83

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l LGS FSAR examination of circumferential pipe welds. Inspection l!

ports should not be located in that portion of the guard pipe passing through the annulus of dual barrier containment structures.

D. For those items requiring ISI, a baseline or preservice examination for establishing the integrity of the original condition is also required by the ASME Code.

3. Confirm that the augmented examination for high energy system piping is maintained throughout the entire piping system up to the outboard restraint. If the restraint is located at the isolation valve, a classification change at the valve interface is acceptable.

4. Confirm that welds between outboard containment isolation valves and piping restraints are included in the PSI and ISI program plan as required.

RESPONSE

1. Limerick does not have guard pipes on piping requiring ISI.

Section 6.6.8 has been changed to delete references to guard pipes. j v

2. A. Protective measures and structures are located, to the greatest extent possible, so as not to prevent access for in-service inspections.

B. High energy fluid system piping between containment isolation valves is required to be 100% volumetrically examined (both circumferential and longitudinal welds) during each examination interval.

l l C. Limerick high energy fluid system piping does not use guard pipes.

D. Highenergypih'ingrequiringISIreceivesabaseline (preservice) examination to establish the integrity of the original condition of the welds.

3. Augmented examination for high energy piping is maintained out to outboard restraints (item 2B above).

4. Welds between outboard containment isolation valves and piping restraints will be included in the PSI plan as required and will be included in the ISI program plan as required.

O Rev. 21, 06/83 250.4-2 m J