ML20210K367

Forwards RAI Re ECCS Pump Suction Strainer Mods for Plant, Units 2 & 3

ML20210K367
Person / Time
Site:	Peach Bottom
Issue date:	08/14/1997
From:	Padovan L NRC (Affiliation Not Assigned)
To:	Hunger G PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
References
TAC-M98684, TAC-M98685, NUDOCS 9708190237
Download: ML20210K367 (4)

Text

_ _ _ . _____ ___ ___-___- ____ _ _ _ _ _ - _ - _ - - .

. August 14, 1997 Mr. George A. Hunger, Jr.

Director-Licensing,'MC 62A-1 PECO Energy Company Nuclear Group Headquarters Correspondence Control Desk P.O. Box No. 195 Wayne, PA 19087-0195

SUBJECT:

' REQUEST FOR ADDITIONAL INFORMATION (RAI) RELATED TO EMERGENCY CORE COOLING SYSTEM (ECCS) PUMP SUCTION STRAINER MODIFICATIONS, PEACH BOTTOM ATOMIC POWER STATION (PBAPS), UNITS.2 AND~3 (TAC NOS M98684~

AND M98685)

Dear Mr. Hunger:

PECO Energy Company.(PECO Energy) submitted a May 5,~1997, letter to the  !

NRC requesting license amendments to obtain NRC approval for' PECO Energy to install replacement ECCS pump suction. strainers at PBAPS Units-2 and 3. NRC i

approval is necessary because PECO Energy determined that the proposed strainer modifications constituted an Unreviewed Safety Question. We determined that we need additional information to complete our evaluation.

l Our RAI is enclosed. Please contact me at (301) 415-1423 if you have any

(

questions.

Sincerely,

-/3/

L. Mark Padovan, Project Manager Project Directorate I-2 Division of Reactor Projects - I/II Docket Nos- 50-277/278

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Enclosure:

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\ August 14, 1997 Mr. George A. Hunger, Jr.

Director-Licensing, MC 62A-1 PECO Energy Company Nuclear Group Headquarters Correspondence Control Desk' P.O. Box No. 195 Wayne, PA-19087-0195

SUBJECT:

REQUEST FOR ADDITIONAL INFORMATION (RAI) RELATED TO EMERGENCY CO COOLING SYSTEM (ECCS) PUMP SUCTION STRAINER MODIFICATIONS, PEACH BOTTOM ATOMIC POWER STATION (PBAPS), UNITS 2 AND 3 (TAC N05. M98684 AND M98685)

Dear Mr. Hunger:

PECO Energy Company (PECO Energy) submitted a May 5, 1997, letter to the NRC requesting license amendments to obtain NRC approval for PECO Energy to  !

-install replacement ECCS pump suction strainers at PBAPS Units 2 and 3. NRC approval is necessary because PECO Energy determined that the proposed strainer modifications constituted an Unreviewed Safety Question. We determined that we need additional information to complete our evaluation.

Our RAI-is-enclosed. Please contact me at (301) 415-1423 if you have any-questions.

Sincerely, u oL --

L. Mark Padovan, Project Manager Project Directorate I-2 Division of Reactor Projects - I/II Office of Nuclear Reactor Regulation

{

Docket Nos. 50-277/278

Enclosure:

-RAI cc w/ encl: See next page .

Mr George A. Hungar,_Jr4 Peach Bottom Atomic Power Station',

.a PEC0-Energy-Company; -Units 2 and 3--

cc

J. W. Durham, Sr., Esquire Chief-Division of Nuclear Safety Sr. V.P. & General Counsel PA Dept.-of

'PECO Energy Company- Environmental Resourcer-

-2301 Market' Street, S26-1 P.O. Box 8469 Philadelphia, PA 19101-.

Harrisburg, PA 17105-8465 PECO-Energy Company ATTN: Mr. T. N. Mitchell, Vice President

_ Board of Supervisors Peach Bottom Atomic Power Station Peach Bottom Township

'1848 Lay Road R. D. #1 Delta,-PA 17314 Delta, PA 17314-PECO Energy Company Public Service Commission of Maryland ATTN: - Regulatory Engineer, A4-SS _ Engineering; Division Peach Bottom Atomic Power Station Chief Engineer 1848 Lay Road 6 St. Paul Centre Delta, PA 17314 Baltimore, MD 21202-6806 l Resident Inspector Mr. Richard McLean U.S.- Nuclear Regulatory Commission Power Plant and Environmental l

Peach Bottom Atomic Power Station Review Division L P.O. Box 399 Department of Natural Resources Delta, PA -17314 B-3, Tawes State Office Building Annapolis, MD -21401 Regional Administrator, Region I

-U.S. Nuclear Regulatory Commission Dr. Judith Johnsrud 475 Allendale Road National- Energy Committee-

-King of Prussia, PA 19406 Sierra Club-433 Orlando Avenue Mr. Roland Fletcher State College, PA ;16803 Department of Environment 201 West Preston Street Manager-Business & Co-owner Affairs Baltimore, MD 21201 Public Service Electric and Gas Company A. F.-Kirby, III. P.O. Box 236 External Operations - Nuclear Hancocks Bridge,.NJ 08038-0236

- Delmarva Power & Light Company P.O. Box 231 Wilmington, DE 19899 Manager-Peach Bottom Licensing PECO Energy Company _

PECO Energy Company- Nuclear Group Headquarters Plant. Manager. Correspondence Control Desk Peach Bottom Atomic Power Station P.O. Box No. 195 1848 Lay Road Wayne, PA 19087-0195 Delta, PA 17314 1

s L

RE00EST FOR ADDITIONAL INFORMATION-PEACH BOTTOM ATOMIC POWER STATION. UNITS 2 AND 3 ECCS PUMP SUCTION STRAINER MODIFICATIONS Please provide the following information:.

1. Did you submit net positive suction head (NPSH) calculations to the staff during the power rerate review? If so, please-provide the NPSH calculations submittal date.

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2. Please provide NPSH calculations, if you did not >reviously submit the

> NPSH calculations to the NRC. The calculations siould include the working

, equation used to calculate NPSH, the NPSH required and available, and all assumptions and losses considered. Provide a time-dependent NPSH-required versus NPSH-available curve,-if available. This c.urve would be similar to the curves provided thatNRC.

to the the Dresden, Pilgrim, and Monticello licensees recently

3. In the Current Design _ Basis section of your May 5,11997, _ letter, you indicated that "The available NPSH margins for-the RHR-and CS pumps are currently defined as 9.6 feet for RHR and 8 feet for CS with system flow-rates of 9500 gpm-for RHR and 3125 gpm for Core Spray." This margin does not appear to be consistent with the margins discussed in your July 20, 1994, letter responding to staff Requests for Additional Information.-

Response 2 lof your July 20, 1994, letter indicates that'"the NPSH margin

.for the RHR pumps was reduced from 8.8 feet for the current conditions to 8.1 feet for power rerate. The'NPSH margin for the core spray pumps was reduced from 9.9 feet for t'ne current conditions-to 9.2 feet for power rerate." Please explain the. discrepancy between your two letters.

4. In the NPSH Margin section of your May 5,1997, letter, you indicated that

...the proposed design basis for sizing the new replacement strainers is to limit the head loss of a fully fouled strainer to 2 feet'less than the NPSH margin for each ECCS pump for those accident conditions specified above." What amount of containment overpressure credit does this-reduction in margin relate?

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ENCLOSURE

UNION OF CONCERNED SCIENTISTS August 5,1997 Mr. L. Joseph Callan Executive Director for Operations United States Nuclear Regulatory Commission Washingtoa, DC 20535 0001 SUBJECTt FIRE PENETRATION SEAL QUESTIONS

Dear Mr. Callan:

Per my FAX dated August 1,1997, and our telephone conversation on that date,I am respectfully submining questions on fire penetration seals on behalf of Mr. Paul Ounter of the Nuclear Information A Resource Swvice and UCS. Our intention was to submit questions to you on Monday, August 4, i 1997, but we were unable to meet our schedule.

l Mr. Gunter and I would like to arrange a public meeting with you to discuss the issues raised by these l questions. The purpose of such a meeting would be to rsach a common undwstanding of the fire l penetration seal concerns and aaree upon a course of action to resolve these concerns.

1.

l While our fire penetration seal concerns apply to the Salem Generating Station, we recognize that they are unlikely to be resolved prior to the restart of that facility. Since the concerns also apply to many nuclear power plants which r-e currently operating, we concede that the concerns need not be a rsstan constraint for Salem Unit 2.

We look forward to pursuing resolution of those concerns with you.

Sinceraly, 0

David A. Loch aum Nuclear Safety Engineer cc: Paul Ounter NIRS 9 2anys/*

Weehsteen Omme: 101s P Ettet NW Sute 310 . Washhsten DC 200 6.W.ds a 3e1432490e . fax: 3:24824405 CambrWge Omos: Two Breme Square CambrWee MA 02234 9105 8174474652 . PAX' e17444 6406 CaWomie Ofnce; 2347 &natuet Avenue Sute 203 Sorteley CA S47o41547 510443-1872 PAX:51644S4786 Attachment

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• I August 3, Ip97 Pass I of 6 NIRS / UCS Mrs Penetration Seal Questions

, NONCOMBU571BILITY OF F1RE PENETRATION SEALA 1-10 CFR Part 50, Appendia R Subpart III.M. " Firs barrier sable p is asel goalineation,"

states:

" Penetration osal deelgas shall utillas only sonoombustible meterials and shall be qualified by tests that are comparable to tests need to rate Are barriers."

10 CFR Part 50, Appendix A, Osneral Design Criterion 3. " Firs protection,* otates:

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• Nonoombustible and best reistant materials shall be used wherever practical throughout the unit, particularly is locations such as the een'annment and eentrol room.' '

Guidance on the NRC staffs intention for "wherovw practical" appear in Standard Review Flan Swtion 9.5.1, " Fire Protection Program,* Rev. 3. July 1981:

"The following spwific critorie provide information, recommendations, and guidance and in general descrb a basis acceptable to the staff that may be used to meet the requirements of ISO.48, ODC 3 and 5:

a. Branch Techaloal position (BTP) CMEB 9.51 as it related to the design provisions given to implement the Arv protection program.'

' Openings through Ars barriers for pipe, acadult, and cable trays which separate Are urus should be sealed or closed to provide a fire resistanos rating as least scual to that required of the barrier itself. Penetration designs should utilias only sencombustible materials and should be qualifial by tests."

According to NRR Office Letter No. 2, " Standard Review Plans for Safety' Evaluations," dated August 12,1975, W SRPs [ Standard Review Plans) repruant the integrated result of the hundreds of ocascions choices made by the staff and by the nuclear industry la developias design critaris and dwiga requirements for nuclear power plants. Now that the plans are published and la us, they represset the most donaltive basis available for specifying NRC's interpretation of an 'aceaptable level of safety' for light water esactor facilities."

De NRC staff is presently revising the Standard Review Plan,la the draft version of SRP 9.5.1 (Standard Review Plan Swtion 9.3.1, " Fire Protectioa Program," Draft Rev, d, April 1996), the staff proposes to suand "wherever practical" so include the Are barriors themselves la addition to tbs Are penetrarios saals:

"The following spwific criteria provide information, neemmendations, and guidance and in general describe a basis acceptable to the staff that may be sud to swt the e requirements of 10 CFR 550.48, GDC 3 and 5:

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August $ 1997 Pass 2 of 6 !

l NIRS / UCS h Pesotretion Seal Questions l a. Braneh Techalcal Posities (BTP) SPLB 9.51 as k reisted to the dealsa i provisions givoa to impleaset the Are protection program."  ;

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' Openings through Are barriers for pipe, sonduit, and sable ersys wklok separate fire areas should be sealed or slosed to provide a Are asistemos reting as least equal to

est voquired of the barrier itself. Stewstural Are barriers (e,s. walu, floors, esiliass),

includtas penetraios designs, should stillas only noncombustible materials and should j be quali5ed by tests la escordanos with the applicable seerJons of NFPA 251 and i ASTM E119."

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! Mr. William H. Ruland of NRC Region I staffindir.med that the 1976 version of the Branck l Technical Position attached to tne 1981 and 1996 3RP 9.5.1 does mal costala the fire l penetration seal sosoombustibility requironnt.

! QI What is the bistorical backgrened es NRCs malyses med to develop ad leelede

! %encombustible materials"is its guidace decamese and segulationst 4

! The NRC staff has recently been moolving a comparable issue lavolving Thermo. lag fire i barrier isstorial which is combustible. In a lettw from Conrad E. McCracles, Chief. Plant l Systezas Branch, Nuclear Regulatory Commission, to Alex Marion, Manager . Technical

! Division, Nuclear Energy Institute, "Thwmo Las 3301 Combustibility Evalusion

! Methodology Plant Somning Guide," dated March 13, Ip93, the NRC staff mainta'. nod the

position that noncombustible materials must be used

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"On the basis of its combustibility tests and review, the staff concluded that Thermo.  !

l Lag 3301 fire barrier meerial has combustible oberectoristics similar to those of r*her i nuclear power plant combstible materials, s9ch as fire.rotardant plywood and sWe l

! Jackets. The staff also concluded that the NE! method does not provide a level of Are  :

1 safety equivalent to thet specified by existing NRC Are protection regulations and l

, guidelines. Thefore, the staff will not accept the use of the NEl guide to justify the  !

l l use of Thermo Les materials where sonoombustible materials are speci5ed by NRC

fire protection requirements or to assess the sombustibility hasards presented by

Thermo Las massiials."

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i Thus, noncombustibility of Gro penetration osals appears to be an implicit squiremsat of 10 l CFR 90.48 and Appendix A GDC 3 and to be an explicit sequirement of Appendix R !!LM.

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! Q2 hw does the NRC staff seconcile 6e guidance la 3RF 9.5.1 and 6e position taken es Heruno lag with is secent claises that Am penetredes seals need set be seacombastible?

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August 5,1997 Fase 3 of 6 NIRS / UCS Fire Penetration Seal Questions AFFIJCASEJ1Y OF AFFENDD( R, SUBFART ELM la a loner from Chalman Jackson to Senator Ridea dated July 29,1997, the NRC explained abat Appendia R Subpart !!!.M only applied to anclear plaats licensed prior to January 1, 1979, which had an open item on fire barrier penetration osals at that time.

Q3 What as the noclear plaats forwhich Appendia R Sebpart ELM appliest <

The NRC staff has roosntly slaimed that nonoombustibility is a requirement of Appendix F, Subpart Ill.M. but not of to CFR $$0.48 and Appendia A GDC 3.1f this position is correct, then noncombustible fire penetration seals are only prohibited at some, bet not all, older nuclear plants. Newer nuclear plaats (i.e., those licensed aher the Browns Ferry fire of 1975) can use combustible fire penetration seals according to NRC claims..

Q4 1s h cmdible that the NRC4 fire protecties aquimments weald mally have becoine less rigomus for nuclear power plaats licensed digt the Browns Ferry fim?

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• August 5, Ip97 Pgs 4 of 6 NULS / UCS Fles Penetration Seal Questless TECHNICAL BASI 5 FOR NONCOMBUSTIBI2 FIRE PENETRA'!)ON SEAL MA'!ERIAL la a letter Dom Chainsna Jeeksen to Senator Bidea dated July 29, Ipp7. the NRC explained that "h NRC staff plans to propose a rule change that would eliminate the Appendix R requiresient that penetretion seal materials be sonoombvetible since there is no technical basis l

for it."

i in 55CY.p6146, ' Technical Assuesset of Fire Barrier Peneeration Seals in Nuclear Poww Plants," the NRC staff recommended that 'the material neacombastible criterios be removed l

Dom Appendix R and the SRP.* I QS $ lace abe NRC staff has set yet changed the mies and slace licensees have set yet applied for er been granted devlasionalesemptions from abase tegalvements, is to NRC staff % stated intenties to change a agulmien psally an acceptable (e.g. legd) subsdente for the mismahlag peseess la which the public has as least as oppossunity to segister opposident The technical basis for the NRC staff's senoorn about combustible Are penetration aest meterial is explicitly detailed in a safety evaluation attached to e letter from Robert M.

Bemero, Director . Division of BWR Liceuing, Nuclear Regutstory Commisaloa, to Edward G. Bauer, Jr., Vios Prwident & Genwal Counsel, Philadelphia Electric Company, 'Esemptior, from Appendix R to 10 CFR $0 Concoruing Penetration Seals and Fire Detection," dated November 14,1986:

"The staffis conostned that whom combustible materials are used la penetraties sesi ,

such asterials may be ignited and eransmit a Are hem one Ars area to anothw."

Q6 Was the NRC staff wrong to believe la 1936 that them gg a techsled bois for sencombastible flee penetraelos sed masedd? Oris the NRC staff wmng to believe new that them (Lag technical basist .

leformation gathered during the Are endurance test of RTV silloca foam performed by the Undwwriters Laboratory of Canada in 1996 indicate that hydrochloric acid (HCL)is a byproduct bom b burning fees, ne videotape of this test clearly indicated thica smoke from the burning foam on the aos Are side of the aikaulated penetration.

Q7 Does the NRC staff have say lafennasies which indicanas the ognipment, perdentady electdsd compcseats, on the unospesed side of a fim penserssion seal with silicea foam will met be adversely affected by the bypredeets, including Seet and ask? Would set the see of combustible fim penesraelen eed asserld latroduce a fallen mode (La., essase as naseviewed safety quesden) shes is not pasent wish nescombus6ble fim penetnaies seal materials?

la the NRC Office of lavestigation's Official Transcript of Proceedings of the lavestigative Interview of Hitoshi Takahasi, Snior Marketing Supervisor Fim Stop Product Line, Dow Corning, dated August 24, Ip94, Mr. Takahasi stated that in the 1984 to 1987 time frams he

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• l Assust 3,1997 Page 3 of 6 NIRS / UCS Fles Penetration Seal Quastions responded to a situation at the Perry Nuclear Power Plant whars RTV silicos foam had bees

, " abused". Mr. Takahnsi testified that " abused" meant "that some air pocket beklad had broke out seal whors the hydrogen sw kind of accumulated which was seeped out and uploded latn on type situation? In the Dura 5ystems videotape of the three hour fire enderance tut conducted by the Undwwriters Leberatory of Canada,it is stated that hydrossa saa sesorated by the two part RTV silices foam causes the material to "anap" and produce a friction fit.

Q8 le NRC swg of able event er other events when a fire penetrusion osal een ammally become the Ignities sonne?

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, August 5,1997 Page 6 of 6 l NIRS / LICS 71re Penetration Seal Questions 1

COMP!.EXrIY OF IJCEMgMG BAgES In a tener from Chairuse Jackson to Senator Sidea dated July 29,1997, the NRC septained that Appandia R Subpart !!!.M only applied to asoloar plaats lieansed prior to January 1, 1979, which had an open item en Are banier penetration seals at that time.

, It seems fair to conclude that each operating nuclear power plant has valque licenslag requirements bued on the regulations in offset at the time and the eonditions mader whloh the linesses were issued.

Q9 Ilow eaa the NRC staff develop backfit analyses for all opersafeg plant er even a sobgmop of operating plass if every plant has solque licenslag basas? How emi the owners gompe and NE! peepare and advocese Wde" industry positions en lisenslag lesets?

la the NRC OfGoe ofInvestigation's 03icial Transcript of Proceedias of the investigative Interview of Hitoshi Takahasi, Scalor Marketing Supervisor Fire Stop Product Line Dow Corning, dated August 24,1994 Mr. Takahesi stated:

• there are so many variablu in the fire test itulf (ASTM E 118), Arst of all, design you claim you passed Gret time around may not necessarily be the single design you subjected to the test and qualified for that design. You could run 100 tests, literally speaking. Literally you can run 100 tests for the same design. If one passes you can quality that design. So was the situation. What my contention was you are stretching the ability of the product way too thin and it might be almost 50/$0 chances of passing or failing, especially if you are careless in doing the installation that might sense some failure."

The ladividual Plant Examinations (! pes) prepared for Salem and other suoleer plants implicitly assumed 100% success of the Are barriers, including Gro po.t.etration seals,la preventing a fire in one fire mona/ area from affecting an a4assat fire mone/ area.

Q10 Based on !afenasales that fisc sedurance testing conducted maderlabosatory condideas is set 100% successful and liessses evest seports and NRC laspectica poports indicating that fim pensinsion seals am periodically found la a degraded or senconfenslag condition, me the IPEs sentenservadvely dnennislag fim dak?

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