ML17187A797

Application for Amend to Licenses DPR-19 & DPR-25,App A,Tss, Section 3/4.7.K, Suppression Chamber & Section 3/4.8, Ultimate Heat Sink, to Address Issues Re Efforts to Reconstitute Design Basis of Containment Heat Removal Sys

ML17187A797
Person / Time
Site:	Dresden, Quad Cities
Issue date:	02/17/1997
From:	Jamila Perry COMMONWEALTH EDISON CO.
To:
Shared Package
ML17187A798	List: ML17187A797 ML17187A799 ML17187A800 ML17187A801 ML17187A802 ML17187A803 ML17187A804 ML17187A805
References
JSPLTR:-97-0034, JSPLTR:-97-34, NUDOCS 9702240108
Download: ML17187A797 (100)

Text

{{#Wiki_filter:* 1. ~ ~;*:;;,:~ Commonwealth(Edison ~pany Dresden Generating Sta9 6500 North Dresden Road . Morris, IL 60450 Tel 815-942-2920 r /. February 17, 1997 JSPLTR: 97-0034 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D. C. 20555-0001

SUBJECT:

Dresde~ Nuciear Power Station Units 2 and 3 ComEd Application for Amendment to Facility Operating Licenses DPR-19 and DPR-25, Appendix A, Technical Specifications, Section 3/4. 7.K, "Suppression Chamber," and Section 3/4.8.C, "Ultimate Heat Sink." Docket Nos. 50-237 and 50-249 Pursuant to 10 CFR 50.90, ComEd proposes to amend Facility Operating Licenses DPR-19 and DPR-25, Appendix A, Technical Specifications (TS), Section 3/4.7.K, "Suppression Chamber," and Section 3/4.8.C, "Ultimate Heat Sink," to address issues resulting from ComEd's efforts to reconstitute the design basis of Dresden Station's containment heat removal system. This license amendment provides the basis for the following: Increase of the maximum Technical Specification Ultimate Heat Sink temperature from 75 to 95 degrees F. Increase of the maximum Technical Specification maximum Suppression Pool Temperature from 75 to 95 degrees F. Use of the available containment pressure to provide adequate net positive suction head (NPSH) for the low pressure emergency core cooling system (ECCS) pumps. Use of the SHEX code for the containment analysis. Use of ANS 5.1 Decay Heat Model. Increase of the maximum postulated post-accident Suppression Pool Temperature from 160 to 176 degrees F. -r~t£~~°&fg~ ~~g;7-v -*-*

p.

PDR f c.Jr~~ d_iotr1 bl)~-.¥1: lllfl-~ PDIL A Unicom Company

\\ \\ USNRC Page2 February 17, 1997 Included with the above are closure of the Containment Cooling Service Water System (CCSW) issues regarding Low Pressure Coolant Injection (LPCI) heat exchanger pressure differential between LPCI and CCSW, reduced heat exchanger capability, and reduced CCSWflow. In addition, plant modifications to the ECCS inlet suction strainers, are being evaluated. These modifications have been initiated to mitigate the circumstances outlined in NRC Bulletin (IEB) 96-03, "ECCS Suction Strainers." The plant modifications are being installed at presden Station per the schedules outlined in ComEd' s responses for Dresden Station related to IEB 96-03 (i.e. Spring 1997 as described in J. Hosmer letter to NRC dated October 31, 1996.) To support the efforts associated with the reconstitution of the system design basis and to incorporate the effects of the associated plant modifications, ComEd has performed design calculations for the affected plant systems to demonstrate that sufficient heat removal capability and ECCS pump NPSHremain for the applicable spectrum of postulated Design Basis Accidents. ComEd has concluded that the revised analyses demonstrate that, for the applicable spectrum of postulated Loss of Coolant Accidents (LOCA) and main steam line breaks, the ability for both short and long-term core Gooling and containment heat removal are not compromised. In accordance with the provisions of 10 CFR 50.59(a)(2)(iii), the aforementioned issues, if reviewed separately, would require NRC staff review and approval per the provisions of 10 CFR 50.90 as Unreviewed Safety Questions because: "the margin of safety as defined in the basis for any technical specification is reduced." However, in conjunction with the design basis reconstitution efforts for the Containment Heat Removal System (CHRS), in order to maintain consistency with these revised analyses and to restore the Technical Specification Limiting Conditions for Operation (LCO) for the Suppression Chamber and the Ultimate Heat Sink to a maximum average water temperature of95 °F, changes to Technical Specification Section 3/4.7.K, "Suppression Chamber," and Section 3/4.8.C, ', "Ultimate Heat Sink," are necessary. Therefore, ComEd requests review and approval of this proposed license amendment request, which includes our design basis reconstitution efforts for the CHRS as support for this endeavor, in accordance with 10 CFR 50.90. The following outlines ComEd's proposed license amendment request. Attachment A to this letter provides the description and safety evaluation of the proposed changes to Appendix A, Technical Specifications, of Facility Operating Licenses DPR-19 and DPR-25, for Dresden Unit 2 and Unit 3, respectively. It includes a description of the current licensing bases for the CHRS, the proposed changes to that licensing basis, and the justification for those changes. Attachment B to this letter provides the no significant hazards consideration determination.

'1" '1.., " "'1

• • .)

USNRC

• Page 3 February 17, 1997 Attachment C to this letter provides new Technical Specification and Technical Specification Bases pages that reflect the results of ComEd's new analyses.

Attachment D to this letter provides a list of the analyses necessary to support the amendment of Facility Operating Licenses, DPR-19 and DPR-25, Appendix A, Technical Specifications, for Dresden Unit 2 and Unit 3, respectively. Attachment E to this letter provides revised UFSAR Sections that reflect the results of ComEd' s revised analyses. Attachment F to this letter provides the LPCI I:Ieat Exchanger Performance Analysis. Attachment G to this letter provides the non-proprietary referenc*es. Attachment H to this letter provides the proprietary references. This submittal contains items which are proprietary in nature to General Electric Company. ComEd has provided the material which is considered proprietary in Attachment H and requests that all material in Attachment H be withheld from public disclosure. ComEd has included, in Attachment H, an affidavit per the requirements of 10 CFR 2. 790 (b) explaining the reasons and circumstances for withholding the applicable information from public disclosure. While the SHEX containment analysis models for Dresden and Quad Ci~ies have been previously benchmarked with respect to peak temperature, we have commissioned an additional set of benchmark calculations to validate pressure response, both short and long term. These calculations are being performed in response to the discussion held between Com Ed and NRR,staff members in the 1/30/97 meeting to discuss the proposed license amendment. These calculations will be submitted by February 28, 1997. The following evaluations have been performed and conditions found to be acceptable. Final calculations documenting the expected conditions are in progress and will be, completed by April 1, 1997. Equipment Qualification parameters at the new thermal conditions. Electrical loading with the ECCS pumps at runout flows Torus attached piping at the new thermal conditions The surveillance procedures will be updated to reflect a minimum CCSW flow of 5000 gpm with two (2) pumps and to verify the ability to maintain 20 psid between LPCI and CCS:W. The appropriate station operating procedures will be updated to reflect the new operating conditions. These procedures will be implemented upon approval of the License Amendment. -~ ---- ------

\\

• ~.

USNRC

• Page4

, February 17, 1997 operating conditions. These procedures will be implemented upon approval of the License Amendment. ,Com.Ed requests approval of this ~endment request prior to April 1; 1997, to support continued operation of Dresden Units 2 and 3 during a period oftime when Ultimate Heat Sink and Suppression Chamber temperatures are expected to exceed the currently approved TS limit of 75 °F. In addition, approval of the proposed license amendment request will support installation of revised ECCS inlet suction strainers l.n the upcoming refueling outage for Dresden Unit 3. Com.Ed requests a 30 day implementation period in order to allow sufficient time to implement necessary procedural and programmatic changes required by the approval of the proposed revised License Amendment requirements. The information provided herein has been reviewed by onsite and offsite review groups in accordance with Company procedures and policies. ComEd is notifying the State of Illinois of this application for amendment by transmitting a copy of this letter and its attachments to the designated state official. To the best of my*kno~ledge and belief, the statements contained in this document are trµe and correct. In.some respects these statements are not based oll"my personal knowledge, but on information furnished by Com.Ed employees, contractor employees, and/or.consultants. Such information has been reviewed in accordance with company practice, and I believe it to be reliable. If there are any questions concerning this matter, please contact F. Spangenberg, Dresden Regulatory Assurance Manager. Sincerely, Dresden S~ation

~-**~,..~.;. -~ USNRC

• February 17, 1997 Attachments:

A.. Background and Safety Evaluation of the Proposed Changes B. No Significant Hazards Evaluation C.. Revised Technical Specifications and Technical Specification Bases Pages D. Calculational Listing E.

• Revised UFSAR Sections F.

LPCI Heat Ex~hanger Performance Analysis G. Non-proprietary References H. Proprietary References cc: A. B. Beach, Regional Administrator - Riii Senior Resident ll)spector - Dresden J. F. Stang, Project Manager - NRR Office of Nuclear Facility Safety - IDNS ~ -- __, ____ - ---*- --* ~- Page.5

• • -***-** ***---*-*~-

50-237 DRESDEN. 2 PROPOSED CHANGE 'IO TEX:H SP:EX:S RE *s~ION 3/4.7.K AND S:OCTION 3/4.8.C, WITH ATI'ACHMENTS A 'ID G. REX:'D W/LTR OI'D 02/17/97 **** 9702240108 .. / / I - NOTICE - THE ATTACHED FILES ARE OFFICIAL r RECORDS OF THE INFORMATION & RECORDS MANAGEMENT BRANCH.. THEY HAVE BEEN CHARGED TO YOU FOR A LIMITED TIME PERIOD AND MUST BE RETURNED TO THE RECORDS & ARCHIVES SERVICES SECTION, TS C3. PLEASE DO NOT. SEND DOCUMENTS CHARGED OUT THROUGH THE MAIL. REMOVALOF ANY PAGE(S) FROM DOCUMENT FQR REPRODUCTION MUST BE REFERRED TO FILE PERSONNEL. - NOTICE - r

,~-.. *:--:-. TABLE OF CONTENTS SECTION TABLE OF CONTENTS EXECUTIVE

SUMMARY

. 11

2.0 BACKGROUND

3

3.0 DESCRIPTION

AND BASIS OF THE CURRENT REQUIREMENTS - 5

4.0 DESCRIPTION

OF THE PROPOSED REQUIREMENTS 25 5.0 *BASIS OF THE PROPOSED REQUIREMENTS _ 40 6.0

SUMMARY

70 -* List of Tables.;. _ - Table 3.1 - Description of Current Operating Parameters 27 Table 4.1 - Description of Proposed Operating-Piiramet~rs _ 37 - Table 5.1-Comparison of Current vs. Proposed Operating Parameters 67 List of Figures - Figure 3.1 - LPCI System Design - -- Figure 3.2 - CCSW System Design Figure 3.3'- Suppression Pool.System Design _ Figure 3.4 - Suppression Chamber and Drywell Spray System Design _ Figure 5._1:. ANS.5.l-:vs:*May-Witt Decay Heat Model -_ -8 9 10 IO 24

• List of References -

91 ' *. ---~*... _.. -.. ~.. :":'"""."

-~

.. ~-., '

_; ~ :... :..**__:* - ~. .~

EXECUTIVE

SUMMARY

ComEd has reconstitilted the design basis for the Dresden Containment Heat Removal System (CHRS). The reconstitution efforts have identified discrepancies between the reconstituted values for system parameters and the values described in the Updated Final Safety Analysis Report (UFSAR). Some of the reconstituted design basis 'values are less conservative than the current licensing basis (CLB) values. To support continued operation of Dresden Station, ComEd requested review and*

received approval of the use of an assumed slight over pressure in the containment for the first ten minutes following certain design basis accidents. The change also requested and

• received amended Technical SpeCification (TS) limits for the maximum average Ultimate
• Heat Sink (UHS) temperature and the-maximum ayerage _Suppression Pool water temperature to permit the plant to operate while further analyses were performed.
• However, the temperature llmits established by*the TS amendment will prohibit operation in the warmer months of the _year..

. ComEd has performed new anfilyses.u5ing the reconstituted CHRS parameters and, in.

• some cases, new analysis.methodologies that are different than thos~ currently described
• in the. Dresden UFSAR but *which have been previously accepted by the NRC sta+/-r for other utilities. These new analyses de~onstrate that.the CHRS can fulfill all of its safety-
• . related functions with the TS limits.for the averagt: UHS water temperatur~ and the maximum average suppression pool temperature *restored to the previous limits of less 0

than or equal to 95 F..

• ComEd' s ~yses of th~ net positive suction head (NPSH) available fo the: Emergency Core Cooling System (ECCS) *pumps have shown that the pumps 'provide adequate flow.
• Our analyses for the.recircUlation phase.have been performed in accordance with the

. _ guideliries of Regulatory Guide'.1.1 regarding the use ofm3.ximilm expected temperature

• of the pumped fluid and with *no pre-existing elevated pressure in the containment.

.. However, these analyses.did not conform to the guidance of Regulatory Guide 1.1. regarding credit for containment pressurization during the transient. This is consistent with the design of the ECCS and CHRS for plants of the Dresden Station vintage.

• ComEd's calculations are consistent with the methods described in Branch Technical Position Contamment SyStems Branch (CSB) 6-1, which include such.provisions as

. maxirriizing h;eat transfer coefficients to containment heat sinks, maximizing the.. containment free v<;>lume, and miXing of sub-Cooled ECCS water with steam in the containment, all of which effectively maximize_ heat transfer from the containment _.: atmosphere,.resUlting lll a cons~rvatiye niinimWn Oyer-pressure... . ~. ~.. ' <.c:."_\\;>*.

• CoJriEd's~'caicw~tions<<)filie:availabl~.. NPSH were b~ed on tlmedependent values of the_

. i *< ~ :.. suction head_ ~d. the.friction h:ead_ arid include a clear* ide~ti_ficati~n and justification of all

• *
• _. * *. conservatism~~ *applied* in determining the water ley~l in the containment. The uncertainty 1i2~!tJ~t:~;L*,f ~~~~~l~ii:~i;i~~Ji*tt~-~~~;:~LxsI*,::;:'..... ~..
• _ -.*.*.....

• • • .=' -

EXECUTivt

SUMMARY

continued -in determining the free volume in the lower part of the containment that may be occupied by water, and the quantity of water that may be trapped in.the drywell by the reactor cavity and the refueling canal, were factored into the calculation. Our analyses include a review of the CHRS to. ensure that sufficient drainage of containment spray water and .. *emergency core cooling water to the suppressio11 pool has been provided. The NPSH analyses for Dresden* Station assure the continued functional.capability ofthe ECCS punips:. The Dresden Station in-service test (IST) program is designed to asst.ire the continued .availability of the pumps through'early identification of degradation which effects the* . -. How characteristics of the pumps. ... The results of the new analyses indicate that the heat removal capability of the CHRS

• * *... **.-_.remains sufficient to maintain containment integrity following*DBAs*. The resultant peak
• -.,~
• suppression pool temperature is higher than the value described in the UFSAR (176 °F vs.

160 °F),_ The consequences ofthls*higher peak temperature have been ev~uated and *

• ~ *:.... *fo\\ind acceptable.

. -. '.>..... - The. de~ign of the the suction strainers is proposed to be. modified to aadress the concerns .: * **_. * ~~ identified.in NRC Bulletin (IEB}96-0_3;. Details of the revised suc~ion strainers,

• including demonstration ofme~ures to mitigate the.concerns in IEB 96-03, will be

. provided at a later date.

• _. '.*: _,_. Finally, ComEd has analyzed.the CHRS to ensure that the design and function of the

system conform to the requifements of General Design Criteria38, 39 and 40. Our

. -~.. -. ".. .analysis ha5 determined the acceptabilit:Y of the contain,meilt heat removal $ystem design by: 1) reviewing failure modes and effects analyses of the system such that all potential

• -single failures have been identified, and confirming that no single failure could*

. incapacitate the entire system; 2) verifying that engineered safety.feattJ,re design standards have been applied; and 3) reviewing the system design provisions for periodic in-service inspection and. operability testing to ensure that the system an:d components are accessible for inspection and all active components can be tested. ... ~ *.. _::::. *-*:u</\\ sumriiary ~f the major issues addressed by this License Aniendment are ~ follows: ~. ._ j --~*

• • ,*;::_'* *: *:: "" *. :-:_.::* _.New de.sign basis values.for CCSW flow rates and for the LPCI heat exchanger

--~ * ;.\\. * *.: **:*.::*~ '.>:; * * *:... (referred to a5 CHRS or LPCUCCSW heat exchanger) are established which differ

.. :*.,. :~.j~~t'Jp:~t:~~:'{-~:: *.*:~from those. in the original ifoensmg.bask-In accordance With the.provisions of 10

-~~--.. __ -~:- -*~ 0'.1- -

• ~ ** ':

~

• .:r

r.,,*~

.EXECUTIVE

SUMMARY

continued perfonnance, if reviewed separately, would require 1'.'JRC staff review and approval . per the provisions of 10 CFR.50.90. Because the CCSW flow rate and LPCl/CCSW heat exchanger perfonnance (referred fo as CHRS or LPCI heat exchanger) support the basis for the Technical Specifications for those systems, the revised parameters resu~t in Urireviewed Safety Questions because: the margin of safety as defined in the basis for any technical specification is reduced." The disc.ussion regarding the CCSW flow rates are discussed in Sections 3.33, 4.2.3 and 5.2.3 ofthis report. The discussion regarding the LPCI heat exchangers heat transfer rates is provided in Sections 3.3.7, 4.2.7 and*5.2~ 7 ofthis repoq.

• Demonstration of adequate containment heat re~oyal with revised parameters
• requires the lise of new.analysis methodologies not previou5ly described in the
• UFSAR. In addition, the resulting peak suppression pool temperature has increased.

. *Per the provisions of 10 CFR.50.59(a)(2)(iii), the revised analytical methodologies . and resulting peak*suppression pool temperatures, if reviewed separately, would. . require NRC staff review.and approval per the provisions of 10 CFR 50.90. Because the revised analytical methodologies and resultjng peak suppression pool

• temperatures support the ~asis for the Technical Specification5 for those systems, the

'.* ** :.. revised parameters result in ari. UnreviewedSafety Question. The discussion

• regarding the usage of revised decay heat methodologies is provided in.Sections

'.,. 1"*

• ... ~*.

'\\' ~ . 3.3.20, 4.2.20 and 5.2:20 of this r~port. The discussion regarding the usage ofrevised *

• condensation stability criteria is provided in Sections 3.3.21;4.2.21 and 5.2.21 of this *

. report.. The discu8sion regarding the revised suppression pool temperatures is... .-.provided in Sections 3.3.10, 4.2.10 and 5.2.10 of thi~ report.* The discussion *

• * "regarding*the Usage of GE's SHEX methodology is.disciissed in Sections 5.2.10 of

. this report. Demonstratio~ of adequate NPSH for the ECCS pump~ req~es credit for

• *containment over pressure in excess of2.0 psig in.the short term. The revised analyses provide a time-dependent profile of available and required NPSH for the

. ECCS pumps. In accordance with the provisions of 10 CFR 50.59(a)(2)(iii), the _revised NPSH. determinations for the ECCS pumps, if reviewed separately, would :

• require NRC staff review and approval per the provisions of 10 CFR 50.90. Because the revised NPS~ determinations. support the basis for the Technical Specifications.

.* *and the. appropriate License Conditions for those systems, the revised determinatfon5

• 1

... *.result _in ~-Unreviewed Safety Question. The discussion regarding the NPSH - long ..i _,; _._~ \\, ~: ** * '...... term evruuation8 is provided *in Section8 3.3J 7, 4:2.17 and 5.2:17of this report. The >;. ;J. ._}':~ ~: * '.. ,.. discussion regarding the NPSH-short term evaluations is provided in Sections --./ ' -~~~~;;, -'~)'.:.*\\ ~- ~--"*:-3.3.is', *4'.2: 18 and '5.2j 8 ~f thi~ report. The discussiofr regarding the revised heat loss' _*>*i1f~~{L~ ~:.-~~~~~:~~ti~l!S;~s ~r~~id~~-~.. ~ec~~~-.3.3.l~~ 4.2._1~ ~d_5*~:19 -~fthis_re~ort. ~~(.~ !~'.~:_*::.

EXECUTIVE

SUMMARY

• (continued)

The ma.Ximum allowable Technical Specification temperatures for the CCSW inlet (ultimate heat sink) and the suppression pool are restored to their previous license

• .limit of95 °F from tlie current 75 °F limits. In accordance with the provisions of 10 CFR 50.59, the aforementioned issues require NRC staff review and approval per the

.*, *provisions of 10 CFR. 50.90. In conjunction.with the design basis reconstitution.. . 'efforts for.the.CHRS, in order to maintain consistency with these revised analyses and

• **to restore the Technical Specification Limiting Conditions for Operation (LCO) for
• ... the Suppression Chamber.and the Ultimate Heat SiDk to a maximum average water
• temperature of95 °F; changes to Technical Specification Section 3/4.7.K,

"Suppression Ch~ber," and Section 3/4.8.C, "Ultimate Heat Sink," are necessary.

. : *.Therefore, ComEd requests review.and approval of this proposed license amendment .. *request, in accordance with 10 CFR 50.90, which includes our design ha.Sis *

• ' :._.:. ~.*.'°reconstitution efforts for.theCHRS. The disc~sion regarding the.TS changes is

..,.. '.:provided in Sections'3.1, 4>1and5.1 of this report The discussion regarding the

• .. * * *. *:revised CC.SW inlet temperatures is provided in Sections 3.3.8, 4.2.8 and 5.2.8 of this
• **.'. report:
• Revised suppressio~ pooltemperatures.are provided in Sections 3.3.9, 4.2.9
• '".*'... *":an? 52.9-ofthis report.**

. "'°'

• ~** -..

,:

• Th~ remainder of ComEd's Safetf Evalwition'is organized as follows:
  • ..Section 1 provides an introduction and overview of the.proposed licens~ amendment
• * * *request.. A description of the key plant parameters* and reconstituted design basis analyses are *s~anzed here..
  • 0*

*. Section 2 in2ludesthe_specific General Design Criteria and corresponding Standard

. Review Pfan(NUREG.:.080Q, SRP) r~quirements considered in the design basis

• . :reconstitution activities~*: The Dresden Station Containment Heat Removal System was compared against the criteria specified in Section *6.2.2 of the SRP "Containment Heat Removal Systems". The SRP ~as determined tO pro~ide a guideline during our.
• *reconstitution efforts to ensure the key aspects of the CHRS were reviewed to confirm

~compliance with. associated NRC regulations. Where the design of the system.is not ill conformance with the SRP criteria,.altemative methods for complying with

• • ..,: - * -** *.- *.specified portions of the":~onupission's* regulations have been presented.

. -.. ~* -. *.* : *- ~.-. - .'_~, 0: :* *.:-:~.. :~*.-_* *.. Section3*.provid~~'.a,descriptioll and summary.ofthe current licensing basis. .1 *-:*-.-- ... 'r.... ;*:- -:.\\.~

• -*...:*<::*.-..*~:::.:-:**

.:,.~: . I. *-_=*..... _... "" :*. ...,. ::. *:i~:~:*-:,.,,.~:'.Section 4_provides a. description of the proposed changes addressed in this License .... ;.-~<*

• ~: *~* <-.. _*. --*.

. :- :: : '.* ~ . ~. :-.. ~-**"":.. . *. '\\ ____ -:....

~.. * .~*:: :.. --*~,,- .. : ::: ~...

";~- -

,..

• Section 5 provides the basis for acceptability of the proposed changes addressed in this License Amendment request.

.. ~... **. -.*. -t'*'-:.. ** .. ~.* -

• • ~-**.: -,

.-.~"'.

• 'T'-:.. ~.;c:... *..r

... -~~.. :.. --,.~ .*r" . ~ ... -~. -~

• -1 **

..,::. <.#'~*~*

• .* f'-1'...

• i.

~*-. -.... ... :*** -* :. ~ ~.'....,.. ~-

c* ~-... :. ::. - INTRODUCTION* The current Licensing Basis for Dresden Station specifies that, to address long-term containment cooling concerns; a combination of flows from one pump of the .Low Pressure *coolant Injection (LPCJ) system (nominal 5000 gpm) and two

• .* punips of the Containment Cooling Service Water (CCSW) syste~ (nominal 5600

., gpm) provide sufficient flow and cooling. These limits with the UHS and Torus temperature maximum temperature of75°F comprise the key current operating limitS. Technical Specifications (TS) 3/4.5.A and 3/4.8.A, specify Limiting Conditions for Operation and Action requirements for LPCI and CCSW

• • *.*respectively. In addition, inlet water temperature and Suppression Chamber
• and/or Pool requirements provide the Technical Specifications requirements that address long.:.term containment cooling concerns..These sections include TS Section 3/4.7.K, '$uppression Cham}>er," and TS Section 3/4.8.C, "{Jhim_ate Heat
• sink."

ComEd has recently embarked on efforts to reconstitute the design basis of the containment heat removal system. Key plant parameters affected by the . *reconstitution efforts include the following issues:

• . :J~. The LPCI heat exchfiltgers vendor datasheet currently lists a heat transfer rate

. of.105 x 106 Btu/hr in the plant safety analysis for a 2 LPCI (10, 700 gpm)/ 2

• .*.CCSW (7000 gpm) pump combination. Revised analysis at these flow conditions

,. have shown that a more appropriate heat transfer rate is 71 x 106 Btu/hr at 5000

• :
• gpm LPCI flow, *5000 gpm CCSW flow with inlet temperature of 95 degrees F *

(CCSW) and 165 degrees F(LPCI). . 2) During:a recent forced ~utage on Dresden Unit 3, it was detemiined that a .. single loop ofoontailunent cooling *service water (CCSW) could not achieve 7000 ~. gpm.* _.*. *: 3},A 20 psid differential pressure is currently required to be maintained bern:een

• the CCSW*and LPCI.flow at the LPCI heat exchanger exit nozzles. This

....... requirement ensures LPCI water does not leak into.the CCSW system in the event .. of a heat exchanger tube leak. Iri order to maintain this differential during a . :design basis accident'cDBA), CCSW flow must be throttled to 5000 gpm.. A . *.. -:ccsw flowrate of7000 gpmwas assumed in the original plant safety analyses. -~

• An' operability evaluation was initially performed by the station and service water

.. ** ~ *.

~_...:.*.:. ******:'inlet temperature was administratively controlled to a maximum of 84 °F (from 95

~ ~-- : :)*.: ~. c. ;:-*... _;~:: *...,:* :'C>f) to en5ure that the design basis contaiilmentheat removal rate of the plant was .,.:..:*.*>.* :>:. *.. ::;_ :,nlaintained with a lower CCSW flow rate

~ '. -~*,<){5~~)

~~~1;P:j:~~;,*:?\\.*. __..,*: ~:,,:; *, *... ~.-: :< * :":. * --~-

. ;-*j*~>;.\\-*~::::_.:*<.> *... A) A discrepancy was:discove~d between the value for head loss across the *., -~... .,.::ntk:*;(~~~~~ <.:/ ~~:~~,:'~.'.EC~S :suction. strainer that _was assumed in the \\]FSAR and a more recent ~ ~i:~il~ll!:il;~1'*1~li~~~~i:',;-;:£~;::,-'.,:> '. ' : ' -',

• • • *** f

.. t. -'ATTACHMENT A. .. :BACKGROUND AND SAFETYEV ALUATION OF THE PROPOSED CHANGES .-. ~alculation.perfo~ed by a vendor. Incorporation ofthis new, higher value. required !}lat the service water inlet temperature be further limite.d to 7 5 °F,.and . *.: : the Suppression Chamber maximum pool temperature *also be limited to 75 °F.

• *(from 95 °F).
• The peak calculated Suppression Chamber pool temperature
• -~*.- -* _.:.-_-. _ *,.- ->*:-.* 0 cfollowing a OBA was reduced to 160 °F. Th~ abovetemperatille restrictions were

<._*:,_~".

• _,.. )-.--'.. '*:_, _b~sea upo~ a contai~ent pressure:of2 psig for the first IO.minutes followi~g a

,,.. -_:': ~~- ."*: =-:._...,,... DBAfo.demonstiateadequate Net PqsitiveSuctionHead (NPSH) for the ECCs*' *

• :,:::.< __...., :_ -.. *:*:system_pllinps (see'References.(18), (21), (22) _and (23)).
• .~:._

~*.. _.* *: -~*.:,_.:;., ~ *.*.. ** -.- ~ 1 ~:-~F:.::.1:;:*:_~,_ :* *;~. 1 ~-

• -~

~'*** :.. ~... * - ;~'. - I -. >-.:--< :-::::.: }~.. ~,.*:-_... ~~ _. :. : ~5) -~During iriitial post~LOCA injeetion, the- ~PCI and_ Core Spray pumps operate "*;..:.~' * ~)c*-::>.*.. *;~-/-.= *'._ ... :.at run -out flows. 'The original 1977

• SIL-151.analysis did'.not *aCldress NPSH
• :: *:\\*.)/"',,;?~'.<~-. *; >\\ <_*>effects. ori ¢e'. Core Spray*pump~ at these flow rates.~ In addition, :ceitfiln input
• _: '.

._::_:*;'._~~.:>://-,, '.~-- ;'.,-- ~'*~:'assumptions regardirig;initial temperatures;*pressures,.levels,*and interactions with

/:/;.~,~~~~~~-

.~< __ : ___. ~:~:;otlier.systeD:i~':were not 1 properly.. atc~unted for,)Vher:addressingthe impacts on*

It{l}i~i~~~f !\\~t~Ji11;~f ~f c~ct

~~*~i~P~k~Jr:e.~c6s~p~P$i:uG~;eLcL*******, *

/~ * -;*o)~;:'~;'-"-~<-~~-<<~: *';.~~~ '2,contaitunent pressure*of more than *2 *psig 'in, the.short.term to ensure adequate, r -"

• I:'..

  ~_;_.- ~/ :,::.;. -"-:.'

.. ~~ ... ~-: NPSH:i~Lavail~ble<<when service *water. (ultimate. heat sink) and :the SuppressiOn*

• I.-~;.;,-*~*-:..--~~ -~J:* -....

~ . : ~ **.,,.* O._..:..""'(.: .... -*-R *. ~ 0 '-, O O - O 0 O O O

• ... --:_~~-~:;;;.~:'.~"'--,~~->~<:: :.:~*),~ ::*_* -:Ghambeq~ool*~a~~r ai:e.*at tjie~r swrimeriiffie terriper~tures (maximum 95.F)._ --.-- *'. :. - :

  • ***~£

'j~4

'*BR~.iBI~~J~~~~~*:if ~~ ~s~~i:;a \\§tli t?<;~~~tu~~n ;; th~'ae~i~ h~i~, * *. *.*. * * * ~: * *.***.* '

.* --:-.":'"'. */ * :.~ ).~-:'".:\\; -*~ "~CoiµEd *performed design calcula~ions.usmg ~e~~analysis methodologies for the... * *,., '._?~;~~,;~/¢~::~.,:.'..>:_~,,:J<::-:/>:..,af'fected pfartt systems_. to "demonstrate that.'suffiCient:heat removru capabiiity and"... *:;*,._. _

• • ~ -.. '..::.-..."-;.***:*.**~*(;;.!:

.A:.:.... - ... ~... ~

• ,- - *0-';,':.'~/,**:-.* -=.- *-. *_.~"':".}?~C~*ptlll!p.~SH remains.for.the applicable"spectrum=OfP.o.stul,ated_Desigri *. *

?~{~ :.. ~':,-;;~::-::* ... _. ~ :..,>'.-Basis Accidents. *:CoriiEd has concfoded*that.tlie-revised analyses.demonstrate ':.=:_*:::::~*.:*:;~;~~:{~:_<: _... _ .. ::~._:>!hat fo~ postulated Lo~~:{jf.coolaiitAc~idents:{Lbc-As)~or main steam line bre~s; - "c.*~*\\~,...,,'.,_,,** Kf -*.;.,, ~-,: **, \\._, .'-*', --'"**.,F:, ' ,~,.'P"f-,. ~

• ."~,-

f.-'

"./ f,.'*;(;)y.!_:i<":F':'-.-~.. . *</the abilifyJor:s.horfaild long..:term. C()re.coolmg ancl~contaiilment heat removal" : -. :*,*,. ~~~~~;;~ .. *-* -_ *=

-_:;\\"?~.~,;~.. : ;:_:: *

~~*,,:;;../.;.":.. -;-<<... Howevei,"Gonffid' s.de.sign 'basis 'reconstitution *ana :plant modification ani:U:yse~ *

_ ~\\ ;-~_/:~::;: ;::~:):- :.:~L:.._.-

.~ *.* ::. utilize*coni:filnrtlenf overpres*sillii.a~on greater tliari 2:psig in 'the short term and ~. ~~~~{:)~:*<. * * -: ~~*r:.

• ~ =_

.:_;'greatef-thaii:o:o'-i)~,ig in th.e: ic>ng. term. t{? 'demoii~ti-aitf.adequate NPSH to' the *Eccs *.. -.-

• _: -__ *. :

~;

.c

:,* -~\\ *.~;;.- :*.. --.. \\::_,~~'..... system pumps~~'Co~d:s)maly"ses atso reswt in ~ong term peak suppression pool

.. ~;~~~*-/ --\\~.:~,,_:_= :*: '.<.oJ*::,-~ 1teiriperatlites: iricreasmg* to :t 76.~:F. '"ill 0 addition~ diff ererit,Values for-head -loss. : _; - -&' 1-**.. :""r*.- -*.. -* ~

• ~-,_.,,. *:. *",

~

• ;< ::*~(.~'-*:~.-*--.. ~~~.:: --~. - ~~**,,,.across the ECG$ suction strainer than were.assumed* in*the-UFSAR required that *

  '~

  ,;-~".-~bi,:~j*£~~; ~ ~:i-. :*.". :.:_ ~-:-~:;:2 -'{th~* se.rvic~ :water _iriiei ~mper.atiife {ultimate heat s'nik) be further-limited to 75 ?F:. -.. -*,. * -

.;i~v~::~~:;~T~iiz~~~:-;~~~i~Ji~f~-~*q~:*~.:~__;,¢)~:i¥~*'.fi}at,Jiie":~ul?~~e~si~~.c~~-1ter ~aXimum~p.001* iein~e~a~e-.:.--;*:.'..*:.-

-*.:, ~---;*;7,,c:-:;;,::.;*::.~:.*:0.,., -'-::-,:,:r'*"filso*be*'lrrmted:to 75.. -fy,(TS-DCO 7 K}** *The'peak calctilated Suppression "*

~~g~:iij=~~:t~B~f {~ii;tf.'i.{~fa~~~q~~b.~~:.p~~~f!~:ri~~~~'$~l~!l~~i~--P~~-~~-red~ce(~o.}~o ~ :crr0m* i. 19* 0f)~ '.~"-<... ~* _-. _ * .;i/'1:~ _.,;_~;~2'.C.. ;Z.-'.j-,~js~¢.:Re(erenqes.*(:l.~);:{iD~,(2i}.anq.(23.)).,_-C<;>inE~'s*tevised analys~s support the _-. _".: ~~- - *,-

• 11,;"..,.. *:1:.0.'"":.ii:.f~0r;~;;.,~"..::-:y-:.;J:>"fa~dsicfre8toi~t1ori*:iiffs--:.ifccY:fof8*c:afi~f-'.fs*h~6o:*3/4-TR.:10~9-5 ~ *..,._,:.. -.-,;-~- _,.: __ :. ;.. ::,.:.~*,:."".~:,... *

. ATTACHMENT A ../* BACKGROUND AND SAF:ETY EVALUATION OF THE PROPOSED CHANGES

• **.. *Therefore, CotTIEd requests review and.approval of this proposed license amendment in accordance With *10 CFR 50.90. '

~. 2.0 ~ ,-. :.... ~ '.,........ *.2.1 *. BACKGROUND. ./. Suminary-0f C~r~ent Lic~nse Basis *. ** ~ .. :.. *~

_:: ~..,.... ~-~'.~.- ->-'... *.:*... -__ ' *. *:............. >... -" :. ;:,

~ *.... _;.** .:Recently, ColriEd requested NRC.approvaLto take:credit for a containment. . < >pre~~\\l.re _rif2 psigfor:~e frrsd~ri (1 O}:minutes following.a DBA to, demonstrate *. *

• _ *:. \\,/;*;=,.7:.. ~

: :*_-.. ~**adequate Ni>SH for the ~~CS system.puinps.. The '2 psig for the first tenminutes

'- *. ::>., '>:)_*;;. ~.. ~:; <'*:. : :coupled ~th:a. 75~F limit. on"UHS and suppression pool water temperafure ~:~** .. ~<*~;::* )'.,:**::*~*': ;F*.'.':</'~.:.-*".*provide:aSsunmc:~ ~atthe'NPSH requirementsare tnet for¢,e ~ccs PUtnPS~;*.. *. ._.:,*~~::<t ;: '.:{>f 5 *.:: "* '"..... ~~-.*. 'Dresden's current :Jicense *basis,(CLB) sp.ecifies. that.'operator*action :is credited at. ~~.

:-'.\\*:*/c.5<\\:'.'Y \\.~i: ;~'... ~ :~.* ~'-;* :._ >~'.~ pressure-.:~f-8.;psig.. aild; a_peak supp~es.sioh.. po'ol te'i:nper~tuie of :*160.: F as described

-:~-:Y~~:-~>;:,:.,:*,_*:._:'.~d>~.*ih.Referep.c~s.O 8);;(21 )~ (22).and ~pprove'd "in:Reforence (23).,.'.! ,irt~}f,S>>r'f :~i~Y!~~i~f!~::~~~ff t2i~ih~~:!~~:d_~ri~ **

::.,::'<~:tj:o.; *. :' ~-~~"'.:*:.. /'*:--: *.*re_conSti~tio~* actiylti~s'have id~ntifi~d system*p~ameters f<?r which the actual

.* *-... -- '.<~ :~* --: _*, >.:"~-*;: c": ~vhlues are.'differenfthan those 'descnbed'in the UFSAR (e.g.; LPCI Heat ... :.:.:.;~.. ,-.:~-\\.* -.::?*--<.<:.Exchang~r'.ci~cy:*ali~.,ECCS~stiction strfilne~J~e~d lo~s)..... Hciwever; based_ upon the

• • * * *: ** :. :. ;";:;.-:r*(,:_..
• ~:>rigiriru ~d.~sign *configiliaiion *and co.mparison t<?.siniilar vintage.Plants, ComEd

, l .._~ 1* _.. 1-.: ' ~*' ~ '* " **, ;;' It _,._,~

• _,r

- *.. **-.:~ -~*~'". ::*; ~;::.:'.. _:.. "~..:..

• believei~that'~i':relian~e o.if overpre.ss1:Jiization.to assure -adequate. NPSH for the

. ?*f i~~*~iIX~}~'** -;:;~~~:~~f,~~f ~~~~ii~~~ib~'..~*~~"*7'.*. '. /'... **~... **.. .. ~~*~;~~;*:,<3> .. **.ConlEd~na5::recon.StirutecLtlu~;(iesign;a:;a5is~of:the*,cHRS* at Dresden.Station.

• .**t

  . \\ *~-

~;.;~*- ~-.";..:°!.:?.#*'*"'"':" **:-*-":.**. :;..-: _*;_~:;,.-*:.;--:-*;.!'.**.::.-...,.,' . :.":.:***:* ~.,* :.*. *- ~ *.... ~ ~.*... *_.. :(:~*.. *:: _'* ~~* * ~...... : *' Because*existing.docUnieµfatiolf-'ari4r.ecords are sketchy.and inadequate to fully .~~ *. ";:*~*:,' :~,~E-<::~~:: -.::; *,.. ~._ :, *.: :*,*,address* ~~~c-e~s, ~~-~~,i~t~<t:-~t!i*~ihe;~eco~siitiJtiofr:efioris and plant * .::.,*~-::.~\\*:*~ *!:-,..~*: * * : -. (.

• niodificatioris;* CoJriE_d used'th~:guidance,provided qyNUREG-0800 (the*

~/;,~~~:~_,_c*\\[-_;;,_*'.-~~~ii~i~i~f iii~tiE~i£;f i~is...

. * ?;-.~~~..;~:;.:.:~~ *. :-;-::.~<. :.:-~.~.::*:*>NR.c *stiitfi~View,and'appioval'is reqwred.t::Therefor~. with approval of this. - ~ '.;.. '-*.. e:*. **r_ -.~c.. -,...... ~

~~

*'.'>'f?£~:*\\:::;::*:~ '£-:;-,_-;,,-::.:-;_' *:::. '.f~chni~al_:.Specifica~ion.~am~~4m~rit'/t,4e~C~,B ~'ajll_:be. updated* and:fully.... ".:

_

.: ~- -*: -~-

r '>>f. _2°'~<:-<,'2:~*:-.,~~~Note~tlia'.t.tlie.Iocug:;iii'.,tfils.:section.'i~oii~the°CHRS, 'aild' nof.tlie"fulLECCS, 'because*'.'. * ** ... :i-~.-. ~ .,*--... -~~.-...... ~*.;z,.. ~*-,~.. -... -- .,~~.:.--... ;,* .:?.;;;;..... -: *. .. *.:;::-._...\\_.../..,.,.** -7'~:('~!. :.:::--*...

• .. i*~.. -

l ~.......,)-.. ~ .... l i*

s.

\\;1~~--r;;~;;~~c.:.:;.:~~-/(~::,,c;r:ilie;clianges'.iii~tb.e~cHRS~reswtiri.g;fiom'.the'.aesigli:ha5iS.reconstitution... -The:.--*-* ** *,..* * -.:~?- _:

• • . *.. i

. ~:- -

• . ' ~*..

ATTACHMENT A

• BACKGROUND AND.SAFETY EV ALUATION'OF THE PROPOSED CHANGES.

effects on sonie:ECCS components are addressed (e.g.,,punip NPSH), but a. . complete discqssion of additional SRP and GDC.criteria that apply to the full * ~ECCS is __ not required or.included. "~,.. *- \\ *-* ~*.:.. *.*_.. -~-.. * : > ~* :'Z:2.\\.*.:.:*-:** -*.. ~:.other° s*y~tem Interactio~s-," *. . *. *: :; :;.-,)~;;a:~~-~~-~_:_::f:\\_:_*._.*:2~2.-:;*.~\\--~El~c~cal l:a~ing ~n-the plant Eme;~ency ~-~es~l Generators (EDGs) ~t.' :> -~ ***-. , : ?:'.)~'*~*/-':~;~*;>:/fF*;.'abov~ rated ECCS puinp flows w_ere evaluat_ed to ensure sufficient-AC electricai.,.-*,. * : *:. **

• .;i;;;id~;~~~l'.~';;~f ~;i~f'.ftOrJs ~tlable to *~~:-o~ the require~*;~ ~~~~*-* i :,.... *.. *... **... '..

• ~ _:1.. ~;.~:.. :~~*-~;;:~~;.~:>1¥:~:.. ~.. ~*:::~:~*~ft:::)*;.'~.~2~~.2-.~-.*~otor cOOling _Wilter temperatures*.wer~-eval~ted.tO_e~ure tha~*lh.ey_ do_:*_*

. :_*; __ ~:<;;._~- *_: :,,._~:~:""'.*. ::; ~:}* ~-."iiot'*exceed environmental -q~alification liinits for the.motors....-

• . ~

_J;L~£~:~i;~~~i-~~,:~;;{.{~0~i!>-:::. ;./_._.::;/;.:: _* __ --:::.. * -".;.. *. .-~--. *:. ~- ~.-,:..:<:' -~'. ~:.. *_. *:.. ":> ;*~

• ~....
• _. *:.-,,, :.,, _,

.,:-.::-:.. ~~'/~~: ~:~:.:~~f~.'~i:~;_*?~i;;~~~-.. ~~~~~::~~L-;>}~~'.*2.:2.3:.*-*~*\\ToruS attacheCtpipirig desjgn -temperatures.Were eValuated to ensufe.lthat-it ~... *~

• -*:~~?*f.-~:\\~;~~'.:t.";:.-:*::';_~~~~~-;reiµ~~s _qperable. for.the*re~~sed:thermal -l~_ading c*~ndition~. _:.. _ *....:. * *

. >*:~;_*_;~:~l'.;>.-:,;:'cf:L~;(:~*~:_~~i'.~;;~)~:;~.:.;.;,': ~.:-::*.:

• ***... \\*-.,,,.... :'

  c>;*;~*~J~;;;~'.>"~*,

.'*~*:* ;:.~.. *,'* :_:.. '*

• -.~-

.~ **;;.~:::t.<'i:':.i:_':!i:'::;:~'.:~t:**.'r~~.:::~3-():.d DESCRIPTION AND BASIS.OF THE CURRENT REQUIREMENTS. : -:*,., *-p-" '* __.,:t.*!,~~1r~l!~~~~}r~~£S~§g~~tP~m~~~~~~:;~~~1~§~:~* ***2*** *:*. ,.,_/.'..~-\\~~~~-:/\\'~Jh.:/;:,* **:. ~-- *.. Technical Specifications, specifies,theLirnitfo.g *conditions*for bperatiOn arici. * *. * ~--_-.-

-:*:*.*,._;~~:::-"~~\\~'

7 ~~!/::~:(,~t..,~~-.-~.Action requirements to ensure thafkey plant CHRS parameters are'corislstent."~th-* *,*,-., **..

~~~:~~*-~~:_;;

'-~.. ::.. *-:--.~}2:~.:;~.;~,~ *,>>

.~ :* L:eonfrols:* Se_ction3.LT.'of:this.repoit:_describes the 0License.Conditions-affected by*'*..

'~** * ~ _' ~~:(";;;.;;; >~: <?. :_., ~~: :~/'*:: Jhe prop~s~d ~hanges: 'Seetfon:3 :2, describes the phy.sical configmaticm of the*. * <.:-_. ~ .. <';~/(,_:-;,,:.... :\\ <*:: "'.-CHRS~. Section J.3 pi:ovidesa ;d~scription of the key *plan( operating parameters*.~-:.*. *:.*

~ >

. ~::: > '.affected by.the proposed licehse ameridnie1:it.  : ::*

~~--~:~~,10

'.:-/:\\Tc_(;lf&~-~{:'.*r<irt~:-::c,':;)/4:5.B_(shutdoWil'Conditions);*proVides*the reqtiirements:forEQCS. The*-Core.

~,~,~~11&~~i~~~iiti~~~~~i~tf l~~J~~l.'.!;';i;,.. ;

:~':*-~.:;.;£.~...:..::zarid

• for'*smaller breaks' following Clepressuriz.atiOn of the reactor by 'the* Automatic* <,. -::.~ >!:** :;.:~

..-.,:,.. !">~.... 'i..~;;~~~~-.. :

• .. *-r -~*or.,.~*-'*

4'~... _' ~.; ~ .. '~"""'

-_.., i-.

'-!.~ -.""*~*... -*l

.

: *-~~:%i::J~p_ressUrizatfon~Sxste#i :CAP~f::~T;h~~~L.P:CI ~yst~~ :W:i~*.a *rii;iiiittj~.of¢!e~ *._ *: ~-.._ *" ~.-- :** * ~:~.. ~ *-. :;:,~..

~~~~~~~3::~~:~Jk:f fil~lii!fllil~I;

... '*.:.=

• i I;
• ATTACHMENT* A*

' BACKGROUND AND SAFETY EV A.LUATION OF THE PROPOSED CHANGES ..* '........ '.'pumps wili provide adeqilate core flooding for break sizes up to and including the 't

_:.'./ double-ended reactor recirculation lirie break, andfor small breaks following..

/*-:*:' <.:*.\\,.:."*. *.:depressurizatio~ by the ADS.: Surveillance requirements provide assurance that

• ...... * :*:~::~:*<?fL-.* -:*::/::* :*:: >.*..,the* L,.PC.I: syste~ ~ll* be oper~ble if required:.Although active compoµents are* *

.,, -_.':,, >: :,,.; ~ ~:,'::-~;}.. ~*.:._: *,,!estable.and full_ fl9w.c~ ~be demonstrated by recirculation.through a test loop ~:;; i'/(i:~.-;:;r:~;,~J}:.;.~:,~ ;* :.auring* reactor operation,*.a: complete ;system 'functional test, requhes the reactor Jo..

:*.'.~*;.:;:*:::Z~~~~:sp:;~~:~~\\{j~}_:}~;'_~:,~be.'.iri_a.s~uttlown:condhion.:**,~e pump discharge_pi.ping is.maintained full to~.. ".*

~-:*;(i":;~.~~:f:'fj.:~:~;}.";'~*~.~.;)<))rev~nt ~~~~r*tiaprm~.r-~ipllage t<?*P~ping and tq,provi~e flow to the vessel at the

• :~..,:\\:_;~.~;;;~~'.z.;<:::~~~:~"'*f-*4:~.. /eai:liest moment>No changes to*these TS *sections.ha~e been identified which are*..

\\-~-. :; '-~... 7.... -:;{.:;,.*'*:.-.'.:.. "";.'"";;:..,'*.... *... 1

• ~*-

... ::._"-',~:,';:""::*::*:,,\\;_",,:/!.'fi.'~\\.s\\_,*; *.::-.nec*ess~*to* support.the reconstitution*efforts: *: * ** .;[~):~,:;;_""',~~i:~K~~~~~?i:};.~~:/ :;;;~.. '\\*~:.. ::,.:..... ~'.:~-;_<~~)~;c~~y:.. _-::':,:;~ ~~;- <.:.::<~.: *~ *,:*; --~:*~*~>>::*.>....... * * >:*.... :*..,:- --~. ~_.. ->. * , * :~.-::'1:::~<~}[<~~~~~;~:'.c;*~~i:;~~*,.,!~3,.4.:2.. *'.~-T echnicaL Specificati,on 3/4.6;f'._ provideir_the requirements*for operable:... :... ......... -'.."'*f**.-~;.~... ;--*!J;!~**-- _....,.A.**... **' ~ 0 O

~-..,

... ::;;r~,~:_,:~'1~~~~J~-;:c2~*~>*3~::} ::.:. 'relief valves arid.the maximum suppression* pool. temperature with an op.en relief _;_;;;f~~~~;~~¥f~~!~~:.~~\\,Yf.J.!itf*:**-. :*; val~e:.' The :~etief v~:V,es.provide -the method to.. depressurize the* re.actor t0 the... ~-:*:~~X~, '"° *;~~;;!t~fJ~~~~?~)~;g.;s~ppre,~sio~~:J}ilo1.:whcilUh~ r~actor-is in rui-.isolated,conCiition: ~.\\Yhen the reactor is .**~-'.* ~.-'.'-.** -~).::-~:c,!;;t.J,;**

• ~'1-

J

• l'

'.*.,..; '10r ~ ... ~..:

i:,,'::'.~¥,~

'\\j:;p.;~*~- * .::~~~-~d~pressuri~e~;,~e:loyv pressure ECCS pllinps*are capabl¢.of providing inventory -

• .-"."c~.-'*--~

~~... -... ., * "rt~*

• "'°'..

t r- ~- ~

,~i;

j,'.~~);1:;:~

'~"';.:

~~~'.bto.the'.vesseLtq assiire~adeqtiate corc;.. cooling

~ Nq,.changes':to'-tlleseTS sections'. "*...' ' '

_.,..;_.*"!:'~~.. ~.. ~~'=' ~ ~ ~ .. ~ i.. 'i.:_.>.-.,:,_.,.-~:.tr,: -, *

r * *.

J ~ * * -.5;:,~::::~.:~.;;.. ~.~u-::~h;,;"*,s>~"i.~*,have.. been-1de~tJfieq,which are necessary;to.support the reconstitution efforts.- : *-

• ~'-tf~r~

  ~~

-;;*. *" :.'~:.)::;/i_~\\;~:~~;~~z~>i}~~~~~>~!:~;.:)i.:~~;):.~~~.. k <*. :.:.;*~:\\;~_:*;;;<':::.:-:.:-*:.:~.,,." l __..... '~_;:;-:,.:;~, *~> r:!.<~ :; :.** *.

7

2'!~~~~ *----"

'-'*"-*~:~._i::S;',~3~~L'l:."' :Tecfulicat~Specificatiori,Sectiori 3/4:8."f\\:provicies the. r.equiremerits *for the.** J _... *:

.(.;.-ir;p,*,r.. **.;:_\\.~

i.;

r...,......;*.r,.-:i.t""' *

~ """::--.* -~*k.r. '*... 1.:.~1 ~--.,...*~* .~...... !'"'": .,)... <(;,""',_,_... ~:-.... r-*- *-*.,.. * ~* .... ~. ~ * -*~. ~~:'~~;i;~~CCSW:system7.:.The c()_itbiinmeiltcooliifg *seI"ViCe':.watei system, 'With.the Ultiniate....

\\

_.;~;:~-;..-;:;~I~~11:~~¥H~~~1-~ilikf~(t?fi<l~s-:*-~~Cieii!:-~,~olliig:*capacitffor'~~-~1itinued operatic>~ o(.tiie-t-".. ~. °'.**f.".:~\\":'1"~\\'i~l'.f.~--::..~"i:t!.t..'..-...**,.. ~....... -... -.~.' *- *.;::./..,S".*.r.*,_.,,,, **, ~ .....,..._--**-~- ,;-r!~***~ ,."" :~* *¥ -~

• <*:>*: :St*_,*f:>.,,~;~~;r~:;,=-f'rlf.~;:-'*;:.. ~~t:contain:nlent~~ooting 'systerii.arid:<,>ther -safety-relatea equipment:( e.g., *c;:csw~ ~~::' ::...,..

__ ::~*:*;:~.:.~;.~~~~;;;i~~1;~~~~!':i~;17:~~eep-fill;1ili~ bo~frol ;~66~.-efi:le~g~~cy,ven#lati~n sySteni~_refrigeratio.~* uiiits), *.. -~ *...... --~.. -~<,~*, r;*L~-~.. ;K;~>"~~~~*;~;~:.;\\: dtiririg~riormahind '.accideri.t c'onditions:'.)rhe redoodant' coolmg 'capaCity: of.the ~-... -~--~:::_:;-~;*~1~~~~~;t.:*!,~,::*;_,.:... ~:<~!;1ystem is:~apabfo'?o{~tllstanding'.a shtgle failure:.. It.'i~ consistent with th~ ~

• ~-*. i' ;-.. 1;-:.-.. 1,,":_,_:..,.-Jt~!... :-:r:.

';;:;:J1.*-"* '::~-"':;: .*.:...... **.!-:'.. :,,-(. -:.: ,.. :..~,,-\\::.... ~ .:_.. ~,::y/;2 :.::?~:r*,,:~:,,~;~~~,{,;.'.;;J:i.. ~.;;_assunipti6iis':used':iri* the~safet}i: aiiaty"sis*to -keep.tlie 'acCident' consequences within '. *. .J~*~.. ~:$.7-:,...-... }:;fu... _~.i*-~... "";~*-~~~*l~\\'!~"'"":"',*... -:,- t

• .:-**.*<::. t-*..i.i~.-:-

--.'?;:- <J-..:::.._,_ ~ .~. :>. ; .~ ~~':::t:-~::0~~::},fJ~~~~i'.£:5~:?~?*:.ac~eptableJJltjluL::,J)rily~two_:.(2),~f~e four (4)"CC$~-pumps are_reqwred.to- * "f<.*-~-"r:."~ ........ :-**.;;~--:~... ~.

• ,.'.::."::::',\\.:.\\;-.:-.:.,\\

i ..ti*":-.:: -

• -:.. *;*_... ':"'..,. *-*_.: __ -.~-;-*_*.

"I,*~... - ~~ ~ .... ~ ~::.;-~]~-~~:.~-~;~ -::t;:..:::,~~.::.* 'cX ::_,'~ *1 ~::.'.-:-prov1_~~';the:_nece_s~WY.. c~o ~µig *cap~c1ty:,::~N o, <?hange~ to.1:he~e TS sectiorn?. are. ~~~~~'.***.

• ,.~~~=~:~ ~

>:,J;~-~~~~-,~~:f;~1~t/f~~~~~G: ~-:-,~~ -~}~_1,:4~:~:~~~~¥.ic~is.~~~.~fi~Ap~1{S_e~~~~--~(4_:_7..J(:_Prqyi?7s-the r~q~e~_~nts ~or ~e.... *, .l.~~..;:~?~:<,:~.~;7~.~:.>:;._'. *~~.. ~... ~;:*:*.~,:;Supp~ess1on C~amber:: l:fte specifications o~ tlii~ section ensure that 'the pnmary _ -.. *,; '::-~. ,, ~""~The~BasesTofTS.'314:7:K.describes.conditions associated Witlf plant *bfowdo\\vn..-.: :.,-:-..._ ~-'

.. ~... :.f.

... *.. ~*..- ... ~ , *,.. _.' --.::i.. ' ~..

• • '*1

~*-r .,. ~" *:'. . *.~; *:~TTACHMENT A ... *~.. ~-....

• .~.* -.. -

. ~... -. ' ; -* ~.. _,. ;-. ** . >BACKGROUND AND SAFETY EVALUATION Of THE PROPOSED CHANGES. J*_ -...J. ...... "Und~r llii1:*pow~r-oper~t1ng con<lition~. blowdo~ &om an initia1 suppression * ' '... *:chamben~vafor temperafufe of 95 °F results in a water temperature of.*.. 0

~-*

:. :.

<.\\.. approximately* 14 5. F.. This peak temperature is low enough to provide complete .... *.:,.,_ <; \\~-" -.

': *:'c6nde~atio~ yi~ i ~quencher* d~viCeS.* However,' a* maximum average suppression

. * <::_>>.,';;~.**. *' .>Pq?l."t~mperatllf.e~of7~-~-~'.-alid ~pproximately}.ps(ofcoriWrime~t press~e is . -: :;. *~ °:,;;: *,~. ;:,!~-*t ~);* ;~,-'~~:.:reqllired t~ *ass_µfe-ad~quate" riet'positive sucti_on presslire for the ECCS pumps*

*-. :-<*:~::.<~:~*.::--:.~:*:{;... ~_:::.;during ihe-.fi~st ten.minute*s-folioWing certain analyzed.accidents~ No positive -

. J*: :~:"*;}::::~~:-~*-~ :.\\:~:-~*.;*~;-~.'l:C~npnrinl:ent.. pr~ssiirtiJs:r~qiiiied fo *assW-~:adequate ~et positiye.suction pressure

---

*i

.. -~ ::,.:*.~~"':~,;*'~Ff~;~:;.); ~Vi3Ar~?:~*;-$uppressm~*'-Chluil.ber~and.Di"yWelLSpray.~;Following a Design Basis Accident* ~-. \\ "'.-\\' *::*~*~.:~(:"~*\\:::-;-;}. r:;;,:~::"-:-;.;:-;?1*' -.;:.. *-:-*v*t*.:.:._:.'4'_.. _,,... _..:*¥::~1 -..

• ,,.;~~-~~ *..

~. ~* -<., **i . --;*"":.. !'~~-;~~;~(}:.~:~~:.. ~.. ":;~ -~~(DB)\\);~e:S\\lPPres.sion ;~haipber* spray. ~ctiori *of LPCl/containment'cooling * . -.".-:.. ~

• I

...... J, ** ,..., '*. *t.c_ - J ~;."'.... ~.....- 1 ~.\\.** *--,......!: - ~. ;- J -. --1 '/ \\

• 1

~:I'.

• * -* :... -* ': ~.-,'.)*;!:.:. ;{.~~;~9:'/i:.z:~;:<systemie~civ.~~ 'I:ieaf:fro~. the.su.ppressiOµ.cliaµiber_:-'vap_or -~pace anq condenses -.* ~ >>:"., * ) ~ :::**

~;..*... ~ .... :h,".......,*:-;~;;t**).i":"_.>:,1 ~.~.:-: y*k!.;;~***_.*.., ::'! _._

• t

~:**,~,

r.

• -.*:::..~..

";~:-:~~;~N :-<;..::, 3~~~~~)steani~;;J11e*:sµppres~1on:~hambens:,de.s1gned_to: abs¢rb*the_'suaaen mptlf of heat. -

• ..,, __ :;~:;*"'J*, **:::~~:~.~~:*;~~X;~,fr()m:the ~ifoitiary ;system.;from.a:bBA:or-a 'rapid :depres~{irization.of the. reacfor..

0 ... *... ~:. *~;~~;;~~~~i:;~~~~~f:i+/-~~~~t~,~~~~:~i~~~~t~<>~~~~@'~j)rjgrfi~i~~[.v~.~e~~i!lie,~~-~-<?~~.. wofo i~paci1*. ~: '.. * "::_. *-* <L~:~.. -. __ ;:_:'" .. ;';.'.;,:{ :~:)~f-~~?.-:~::~-:~~t;cmiJ~Thnierit~pn(f-headefinside"the::~~ppressioQ. chartibe~ :**;,'Periodic* operation *of 0 :*.:: *:;:*:.., *_,.. : ';,* _. -,..) .......,.f. _.'t,,,-\\-"':l'.**'"*-"1.,(".t.~*-.,,....y.. ~**~'1,*.. *..._* ~ * (....,........ _ ******'.... t-'*A' .J* o o, 0 .-.'.. i'~~ :.'.}~;:~i?-~;*~~;/3~~e~i:~§pp~~§~i~~:.. ~~~~~t~¥id ~~.1~ *sptays~may.. ~sO' be -1:1Se4* foll<?wii?-g -~ !?BA**>::;/:.\\~;_: *;:i*:.*, 1 ~ ""*

• -J

~ (_~ ** ' _,._..,._ 'i '>... }....,

• t

,,"i'*F,,..".,.,......-..._

• * " *""1

1.

r.! M ~ ., *.:........ ~: ;E ~-... ~f ;.... ~F<::-'::;-* ""-tcf~sis~-;th~-~mitiiraf.convectjon.aµa_:diffusion it_rixiiig :of 4ydi-ggen an~ oxygen :.. -,.:.;.~ --:*+,~*/~:f: "';.

• ,_~~---~"'-_..*;kj.* 'if*.-,._._,

._.c;

-.~*~*,-:-*-=:."". *:.:---**-*'

• . -**,..:.=:~"*-,*.-

-~.;...,.)_ --.~-, *-

• • • ~ -*

,_:,...., ~-~*-*

-'~ *;. :-.:;:-_ 5,, '.:::.":.-. :,:...:::;:. '::Wh~n _oQt~r*}~:f~.S.;nmmr~.m~nt~:.~e.,iper and.pxygen -~~ncentrat10µ. e~ceed~ 4 %.-" *. "-~~. :.::~~- * *.~.

• _::

'... ".>-~ < ~~.;.r-.~?.:~<:,:\\;::.b.f:iSin~e'=llie.spray :sy.stenj::is~a"*fi.µl~tign,oLtb.e')J~~l/co.ritairilnerit cooling system;:tlie 0 ,... - '_\\;. > .-~

• . ~.: *~;;-../< ::.~:~~~:~-)~'*)~~:-ii1~~ps'.~nGi<>i~.be ruign~d~f~;,_ilie.:sptayiu~dfori dunng:normal operatic>~; bui.- --~-* )*:*:.. "*:~*:'**>~;**:

=--, i-':*:... ~~j:,-~-,-~1:*;}!:.,.. :'i;::.;.;...::Z'.. ~~.... _,1..::.'::*~£:...:;.-:~.-- .-*~1'...,.*=~~"'J',:, .:.~".;..*::......:.--~1.~~-,;;.~.. -

",,..,_......,... ;",..

.".t* *.!

• ~;*':~',

-~\\_

"* :;!~*

1.,.~. ~; -~: >... ~ ~:.~:.:.f.,::.:~:!.?~.. :--:~.-~/~~~~<.>mponent$ r~qurr~d~~o-ope~~e.<fpi::proper,ahgrunent must be*OPERABLE:.Nq :--:;":.*.. *:: *..:"*'.".. -*

• <;;.I

,; ::...;,;.:,' }~*

• --'O:..,_:~'!,,,.; '-.*.:...* :f _
• *~** ~'*::;" >..../:*"-)'-

j.:-:i; -*~';'. ~""'...,* 1 J-.."i

• '*"~ -......... - * **,..,', '

r ,*-*. ~ i *' " '" "l, :;" * . >.:. ::*->-;:-;:"t::,... *~~;;";:-,:::{~-"~.~r:;1ch~ges..to:.~ese~1:S.'sections-hav~:.peen.1q~ntified which are:nec.essary to support'._~*>: ::-~.:c *.,*.. ~.. :*-i,

• • :-}.B!~gtr!4~~~1~~~~futl;l~~ *~.,~,,..,jl~:3r*

0 ~i%l~J~iltt~~~5r~i~,~*,;f (:~~;;.~ :.\\'.Llc"t: -.

• ,~ :*. ** ; *~' -.::-:<;!~.. :-:~~:~~;~~:~~ :.:}3) ~() :T:Te9liiµc

sp"ecmc~~on,.. ection".~/4~7..JVl~provides:*The; re'quirementsf or-:*t". *..* '.:~.., : '._: :

-. * ~,.. *:';>*:*~.~~:~r;::, t~,;:.. :-Supp;~;sfon~:P.ooi~e.()61mt(;F~if0Wfu.fah':a:c~i,deri~:ilie s~ppr~ssion p<.>ol cooiing

: ~:> * :-.':

• . -> :\\::~~-~~::}::,~1T~ _--...,~~!--*;:_fimciio~:O{ilie.i'.Pc116c>ntilhment:'~Sof~g:system*-re~oves.1leattliat ilie *0..

-~- ,,**'.- ~.* * :~ * .. ',-;_*:'"::'.'..;~~:~::~;~~f::~f:i:?~~::~~i)ir~PPPI~~~i~~~~p9t~li~oh{~9R?~~~~~~~~SYS!~~:*Ht~\\yd~~;and~:ifrthe ld~g* ---~_.. *,.... " , : -:-.:, ~... *::;.:~-~~f'.~.~-:;.:;-~~~<{~}f,/~:-~;,tenii;;'fr.om Ui:e'.,oec*ay1ij.eatj~enerate'd bY,~fueU.ri:the:reactor.. cor~. :.:'E~ch:of ~e~'... _: _ * *:; '* ~ --;-. ~- :* -. ~"*;::.:)~:"*-~;;~(ti ~*~~;*~~µpp;~~sio~~p9<>1*.c9.Mkg100p~-:t-6~~i~,'6(~;P.uin1(~<t~~a:t~ex6Iiange£.:.Foi19~ng ;".. _ *.. c~_.

,;. :, ~~:::~::.~~,1~~.-tftJ~~4:~f~!¥a~I<;ls~.'-~tco81~t~~cia~n(:~0eA);:ihtpianf operator~~&iin r~align*the. yruve~ *i~.:* -; -.:;.*< *-L-. * :_;}=~*

~(;.~~~*~f~~?-~~?fi}~:::q~-~~~Ji~;~~'§s~~~q~~~9P.IJ~:~~~~i~rifr~~~t!i~~~~~:Pr~~~i~~:p~rii;:2purii1>*it.*-o~~ ~~~{?:;:~~~~-:::0:;,,:.. :2_(": _.. /,;;:*(;"s~~~~:. ":.=::~~t::';t~shelFsiae_~of.ilieiexclianjers}1'.and 1iischarge)t;back<to*.tlie sU:ppressi9n pool Via the\\/.~,*1'~:,;.~:~~ *.,~ '\\*:. ~ *ii~f"*... :-*.. -.:.::-;:r

... _:;_J~~r~~-.. ~ r-:

-~..... * :'l* :;.. :... ~~-~-~l'~~']{~7ii*-..::$;',... ;:~ ?~~~.:;..~ ~"'...~~:;,_-;_.. ~~~~- ;,.. ~--~.....:'..,.;-Vr.:;-~*

"*.-J*;.:.:*"~-...,.._~r. *-:.*: ** * **....r.--:~

• *~.'

~*'!-::-;-- :... ~;..:r :.. :"".:."'"' !,~ .. "';,.*,,::_s ~:~:,;,.)'::,*

• ;!.'.l~,::'.;'::;°i..~i'.'fill16flow:,t~st'liiies~i!\\l*tl,ie'sam~:tln1~,~.. ~o~truwnent.coohpg service waterJCCS\\Yt.__* ~-.*,: c'- _-**:L

"">>"1.*.:..-..t.;*-~t--:'.="-.?;*: ~.*.,.:'--.u-~,:;.;...,.~:~:*~:-~::.~*-,._*,t::'--;lf"7;:,.:_'--::-2:,...*::'.~"t4. 1 *::~:i,.--.~,..,..,~-:r.:; ,: *~- ~~*0***~-.:~-- ~-: ~~f-.-

• , *._, ~

~~* ... ;~-- r,._,.*"... :{*r;_:-_..';:-:*-*~ '? _, ~-£=~~-,.._ -* ------ k* ~~H!isJpumpec\\':tbfQ\\j.gn"llie:;fube*-s1de;of:;:the*.excha.Qger~:t<Hransfer.'lieat to the external ~: :.r:~,>_.'. *:* },.. *. '":';.6*'1 ~~........ ~ -<t"+-.;;;*-.s'*-~!(*~.... ;.~...,.:p-;..-t;!_-T,-..... *o":"'/.. :.-...r......... *~-r:.!:'"'**.~~-"-P-* ~-... ":" *.;.,;-.. **- .... _, -..,,,,,.,OLf' ~ ~-'"* ~--.. -:--...*.... _..;; -.._:--*..... ~:~:'.

• • eats*** *

<:f~efuU1-ges\\ta~tlle's~~11s*::seetions:11ave*:been~idehiifiea:whlch~are-<:~~~;~::::~~*;ff~~:::~t.:.~~-,,i::~~

• 2:' *

'Cet~, ~t.rvrilir"JiiiIB'fih!!i~~~rts?- *"'" '"'~~~~!!f ;Ws' -,~

• r

-.... ~. ATTACHMENT A ...,-. ~"'-._ ',-. .~.-

• ~**

. *.:'.BACKGROuND AND SAFETY EVALUATION OF THE:PR()POSED CHANGES <*,*-:'.:r: :-:.;* ~-..

• '.~.

'*:~-/:-:,,\\?::~,,-"_;~*:~3:1.7 **,:Teduiic~l-Spe~ification Section 3/4.8.C provides the requirements.for the** .. ~.~~~-. '..;:... ~Fi::;;r~~>:,:'\\:;,~C;*:eJJlt~~te Heat Sink. _Th~ canWs proyide.ari ultii:nate heat 'sink with sufficient....

• ~* ~;i::jf,:~;:\\%K!.ii.~;;~\\~;f;:~~t~ooll~g capac~fy.fo ~ither:pro0d~ _n;ormai cooldoWll of.the ooits, or to mi~igate the

. ~...:.-~/.: ~~:Si~;;;~:;.~~~~~-~;~*'.~';~'j;~.*~ffe.C~S. of accidenfconditi!J.nS -witliiii_ acceptable limits for one unit while .. ::_.: >:.}f~:-~:~*:.:.:)t~~*.::~-~;.Q;,):~:~con*:hicting a'noi:nial cooldowo on the.other wiit..*.. ;... *.*

.--~~~

~*:iJ?,:;::*::*~J~~ttr:~:;(~:,:~~*::.*'~~.::~~<o."

0

• .-~/~~.~;.\\.~:-:... ::~*:*~--~-~'. ***.-,:**

__ -,: ~'-'*~

• :.. _:, -:~<.-....._,, * ;-*;

~~;?

• :~~~;-.;*_;z;~~J~~r$:~;~;J~~*;1_:_~./: ;L~c*e~se'-conditfon_s:-.*pcerise*Condit~ons 2:C(6) and 2.0 to _Facility. *

• .'~*:'°"~:;!.::~s;~'.f;.f:~~;~;~~:ff~,?;;X:-::~Qper~ting*~ice.nses DPR.:i9 ancLDPR-::25.Jor Dresden.Units 2 and 3, respectively,.
• **~-

~*,;:i:_ *** 'f'*~~..=::.'1.:-~~*;. -*~-t*-i:~.. p-*-i;:.-1.-~...... -~- '\\ '\\ ~

• • .:{;-_,:*~;~~~?;,~_*t:?-~i::;~:i.-"-.,* *

~;*e~:2<~C!.~.scrib~*-~ose _condition~, that..allqw *ir limited.@l!lo.unt of containriletjt *overpressure * *

• J.J.;.:J,;:~~f;~~~f~;:r:~"-"'~&".:~f)*,~>~?>*:co~peilsate-*fc_>r,a _slight ~ounf pf net pos_itiye. suction head (NPSH) deficiency.
• >;...:j_~ ****-:-... -"'--*<......

~* -*t.*.1... :r-_.,._.* -.. --.... ~. '*"*""< 1*

• • '"l.-

,t,~:TifF -* ;.;>,. -~?0

• ,c(iffring;fu.ejii:iit~al iinie.periqd.f<?llt>Wirig a'DBA :-iJhese~lice~e.conditioris *a11ow.

-~~--,::

• "'°!"*,...

.'.~*:'.:/;~.. -~~l;\\';;:,;;:._..,*...,,..:t":':ilie~licen5ee}to'changetbe'Updated ~Firiiil Safety:.Analysis Report to allow credit -;*~~~~~~tb; l\\~Ai;;:2~?.~~-,,,,Si~{i~~:~§i.g:~~~µtij~~~b.¥:'.~!~~s~~:t'?!:c?mpens~i~* ~~~-a sflght :iricr~~e*.~~-the~.. t *~

i:;f.\\:~f:~i:';:::

hmw~t,oJNP.Sl:L9efici~ticy,during the.fi,rst.:l O minutes following a' design ba5i~ * <-_ :* .. -1 ~-..:,.;. ~I~:tJ'.,'t1r '.;$~;~c~iCl~ri,i;(D..~~) ;~,~;7~i:~~1;}\\s~1~~~;~;;f:~~-;~~:J:i~: ;;':' )t;~**,, * * ~::.r..* *,*~-~-*~~r~, :\\~*;~ ~<:.... :/:: ~--.. ->,.. * '*

~'?~?-T[2

?s;\\:~;{GiIRS;:cc;rifigmatiori~;;TlitU~1Io\\yiiig' sectiq1f piov.ides.*a (les,crjption *pf.the::*....

• _,,....:~**.* *
  • 1Jilf iilf ii!t!~i~ii~~qz,~~:~,~";**

~~P.~.,~<l<c{>Ii~~n~,9:( ~iqstuigJ>.lAAt._system!) *ru-e:miJy ;phys~cally.affected~as a* result. *~.,~\\.'c* : *

~,:.:o:::

...,.~*,,.......... :('.'.::r.-.~~... r'r*,.\\*.r;~.. :;_,._.*...,... ~.. -..,.:,.,1.*;.'. -;.:~v..:-,.. ~,,*.~t,,;":~*"*~***... t-'

• ..t~'-*.11

.. ~.. "'*-** 'hJ..... -*' **. *.**.-~

• • • ,,.~.

~(;ijie'~qfufi~atiofrpr9.OJe(i)o:Initiga~e*tll.~(concems rfils~d lJY.'~E:[l:96:;0J;.,th~j'.:/" ~*:: ~t:.;.* *..

.::-,_~;;:"f.'-"~;,.:*::;*-*:*.. :..*:-.,G:.-.~-*:"*... _1/.* P

.. :.':.-*~,.-*- :--*:*'......,~-- ~-..... ";*:;.-*-.... :.-* __ -.,.-**1**:.. J~(eop.fjg'µfatioiiW~:,reyi~w~<r@q. ¢xaljiiried'to :ensure.. their.b~i.s remains* V '~- * ~**..:-.. -~~::-r,...~.;-~_,.-*-,.*-r-.....,.. ~-~-:;.:*-... ;- ,~... -.,.. -;"';'*-* !*l*-:::**..!'*.* -""""'-:... *

---** - *1*-*

.*i.. -:::~ *_..,.!., **,_ \\:.*..... * ----.

• .~:~-I"**::.

unclianged~o(See'.F1g(Jre*J~O.below:)~**::t;:.~,<--"';**;:_;.:..,.* 0*-,.. ~. :*::,:.. :,.:, :;.;;... :,. *

-'-'".:' :.~.:

AITACBMENT A .-BACKGROUND AND SAFETY EVALUATION OF THE PROPOSED CHANGES -,J_

: ~..

f!GURE J 0 _ \\_:_ r ~* "*. FIGURE 3.0 CHRS SYSTEM DESIGN ., -* :_*_. :>-'~:." 'The d~sigiibasis of the LPCI subsystem is to provide adequate core ' * *. :_ ::::cooling for various postulated LOCA' s for a rarige of failure sizes from those for which*the core is adequately cooled by the high pressure coolant injection syste~.. up to and 'incltiding the DBA. The :LPCI system provides reactor core cooling for *.

• "a* large spectrum ofloss-of-coolant accidents in conjunction With either core spray

< ;8ubsystem;:The LPCI system is provided with redundancy in critical components _

• -.***:_:'.L _-_-: ' __ :..- *-~--.::.- :-, ~tonieet;reliabilify"reqwremerits~ The LPCI syStem can be operated without

-~'-~:;_ -~ *:: * * * *

• • _, * :.: _:_reliance-.upo'n.offsite *sources _of electrical power.'The LPCl system is designed so *
• * *, -that each.ccnpponent can be tested and inspected periodically to demonstrate
• * ' availabilityofthe_~ubsystem~ In addition to its ECCS.design bases, the LPCI

-: : *,-.. system also provides the _capability to achieve cold shutdown from normal _-.operating conditions. The.containment cooling service water (CCSW) system and . :,.. ~--. - ... ;*._. pressure:relief system are used_ in conjunction with the LPCI subsystem to provide ~. ~ this capability.- A diagram of one train of the LPCI system is pr~sented in *figure ~<:~'. ~--).1 outlining the~systems' key components'. - :. ~--~~

• • *-*~

........ ~:* --~ -.\\-.;~;"'*~-~~- -~-'* ~. . --~

.'. ~ :.

.. -~. I r . *. :~ -~ :-

_ _i ** . r *. :.~*' AITACBMENT A BACKGROUND AND SAFETY EVALUATION OF THE PROPOSED CHANGES TORUS ECCS RING . HEADER TORUS DRYWELL TORUS SPRAY* SPRAY COOUNG Z8 ~TO OTHER LPCI SUBSYSTEMS HX-ccsw ccsw RIVER .. DISCHARGE.

• FIGURE :5. 1

. FIGURE 3~1 - LPCI SYSTEM DESIGN. The CCSW.system is an open loop cooling water system consisting of four

.. ~. ~.ccsw pumps and associated valves,- piping, controls~ and instrumentation.

• • .., * *Schematic.diagrams' of the CCSW systems'for UnitS 2*and 3 are shown in UFSAR

.... ". **.* ~-~gures 9.2~1.and9.2.;2, *respectively.*:*.~~*

~ ~.-. :*. < *.*

• -* *...._*,. *;. *:._;.The.. CCS.W system provides cooln;g water. for the LPCI heat exchangers during

.:'?.~b~~;:{ * .:.. *.*.*'.*/:.. ~'-* ;*ooth acCident.and non~accident conditions,*as*aescribed in UFSAR:Section 6.2.i.

• • .::_.-~t.7 /*- ~ * * '.'.~~:... ;: <~ystem *pipiilg *is ~ged to f omi,two separate, two.pump, flow.networks (loops).

. -'* *:-"l -.

~- :_;

J. :'1--.. -\\-.

~... - -~::.

• -*~:
• AITACBMENT A BACKGROUND AND SAFETY EVALUATION OF THE PROPOSED CHANGES Each pair of CCSW pumps takes a suction from the ultimate heat sink via separate supply piping. Two (2) CCSW pumps discharge into a common header which routes the cooling wafor to that loop's associated heat exchap.ger. At the heat exchanger, heat is transferred from the low pressure coolant injection (LPCI)
• subsystem to the CCSW system, and subsequently to the river. During normal
• plant operation, the CCSW system is not operating. Following an 11ccident or.

other plant evolution which requires containment heat removal, the CCSW system is manually started. Each CCSW pump motor is rated at 500 hp. The CCSW pumps are powered by normal AC or diesel generator AC power. Additional CCSW pump.information is provided in UFSAR Table 9 :2.,.1. The ccsw pumps develop sufficient he~d to maintain ccsw pressure greater than the LPCI presslire in the LPCI heat exchanger. The differential pressure is _. maintained by partially throttling the CCSW flow at the outlet of the LPCI heat. * *

• exchanger. Maintaining this pressure differential prev~nts reactor water leakage

. into ccsw and thereby into the river. The four cc;sw pumps are located in the turbine building. Two of the four CCSW pumps (pumps Band C) are located.in a

• single, cominon watertight vault for flood.protection. To prevent the CCSW pump motors from.overheating; the varilt has two vault coolers.
• A continuous fill of the CCSW ~yStem is provided by the service water system or, in the case of a loss of power to the service water pumps, the diesel generator cooling water
• system may be aligned to provide the continuous fill: This eliminates the potential for water hammer \\lpon ccsw system* startup. The diesel generator cooling water system is.discussed in UFSAR Section 9.5.7.. The Unit 2 CCSW loops also provide a safety-related source of service water to the control room air conditioning refrigeration condensers (see UFSAR Sections 6.4 and 9.4.1 for a description ofthe control room ventilation system). A diagram of the CCSW

.system is presented befow, oiitliriing the systems~ key components. . ~.. . -~:?; ~ :.:.. ~. -* -:..... ~.. _'-. -'* *. -. -*~-. ~- *.-. .~,*.

.I'*-;-

-* :

• t~ -....... *

. ~. *-

• -:~ --~' ':..:: *-

! *.,.~ :.:. '

ATIACBMENT A. BACKGROUND AND SAFETY EVALUATION OF THE PROPOSED CHANGES 2A LPCI HX OP CDOl.J.[R LPCI ccsw HX LPCI FLOW ccsw RIVER DISCHARGE CCSW PUMP VAULT TO CONTROL ROOM EMERGENCY VENTILATION SYSTEM . (UNIT 2 ONLY) FJGURE 3.2 0.. ~ 0.. ~ u u ID ~. ~.*

• t
• FIGURE 3.2 - c~sw SYSTEM DESIGN

, * *

• The *Primary Containment is defined as the Drywell and the Pressure Suppression

... Chamber (also referred to.as the Torus), and a vent system connecting.the drywell* to the Torus. The dryweB comprises a steel pressure vessel, consisting of a

• spherical section (66 ft. diameter) and a cylindrical section (37 ft. diameter), an9 having an overall height of 113 ft. The design internal pressure 'is 62 psig at 281-

. * °F. The design eXternal pressure i_s 2 psig. The drywell*is enclosed in reinforced . concrete to provide shielding. _..*.. :_* ~ ' . ' --~ ---. .. The pressure suppression cruunber compri~es. a steel pressure vessel, which. encircles the ~ell at its base. The design internal pressure is 62 psig at 281 °F.

• . *The design external pressure is one (1) psig._ The*suppressionpoolcontains a large volume of water, which acts as a condenser to condense ste~ in the event

ofa LOCA in the drywell or to depressurize the reactor via the relief valves. This

• volume of water 81.lows for a maximum 50 °F rise in-the temperature during the*

  • initial short term injection phase.of a LOCA. This water volume also acts a5.a

. : :.. **.*., :- source of water for the Low Pressure. Coolant Injection (LPCI), Core Spray,.and High P~essure Coolant Injection (HPCI) Systems. Cooling for the suppression

• -:. pool is accomplished us~g the LPCI heat exchangers.

":'~~ ~!:i:~Z';;;;y~~:~;~f~~:J!:;: <.*;.. ;Eigbt.81 inch diameter vent_pipes ~e-provi_ded:t~ vent the dryw~ll to the *. _* *....

-,..~

.---~_:;*.~. ~:-~*:."/~ 0

• >:;_ ',::,~'\\ :suppre_s.sion poo. l. -Ei~t vent pipe~ exha~ into. a single ~8 inch diameter ring...

."""*.__;~;<*'~* ::* :*.. ;:*~*:header m the.suppression-pool. Nmety-six downcomer pipes extend from the nng : '.\\~~t.f !~i~f f ~~~~~1~,,~'.~,~;~~iiJJ1i~L¥~"~c~>,;;~.**** ;

• • . ** './_::~: ~**** **~-******** :;.:,~;;_.**. ~.*
• _.. -~. ~.... ; ~~.
• ~'. '.

~-* f - :\\. ~--:::::- '. ;* '. ~- '._ ~. _..,..,.:: ;_:;._ --.* \\. - ... ~. ATTACHMENT A BACKGROUND AND SAFETY EVALUATION OF THE PROPOSED CHANGES header into the suppression pool, entering the pool 4 feet below the water surface. Full condensation of the* steam exhausted into the suppression pool from the drywell will occur ifthe exhaust is 4 feet below the surface of the water. The inlets to the vent pipes are protected by jet deflectors so as to prevent damage to

• the vent pipes from missiles and jet forces in the drywell..

The Containment System supports operation of the LPCI, Core Spray, and HPCI Systems*by providing a source of water for pump operation and

• maintaining suppression pool water above the minimum level to assure adequate NPSH available to the* LPClpumps during LPCI, Suppression Pool Cooling and Containment/Suppression Pool Spray modes of operation~*.

,,~ "."". ~ ~- _, REACTOR VESSEL: .ORYWELL DRYWELLSPRAY . HEADER (TYP. Of 2) ..--~_,_ ____________ .::.~:- *;*I._*_.. _**----,--* _r_oR_u_s_R_IN_G_H_EAD_E_R_, ____ __,.I .. :~ FIGURE'* 3.3

• 3.3 - SUPPRESSION POOL SYSTEM DESIGN.FIGURE
• Post accident cool~g.is provided bytwo.modes of~PCI operation: 1) *
• * -:containment(drywell and suppression.pool) Sp~y mode; and.2) Suppressiqn. * * *

-PoOI :Cori ling mode~;.*:-. -* ___.:- *,.. ~ w: ..-~.... - . : *=.. , ~ *. *. !~ ** . :... r.:...,** - ~~' . ~.. ...... ~

. ~._ :*.'.

** _ ** ATIACHMENT A :

. *:*- :.:: :eACKGROUN~,AND SAFETY EVALUATION OF T~IK.PROPQSED CHANGES

• . ConUilruiient Spr_ay Mode-
• . '.1_'

~.

.. ~ *. - ~--' : ~ y\\.--~::~'<-~'::.:*,:*The* C.ort~enf Spray mode i~ designed to_'cooi.hot non-condensable" *_..

• ...... -~*- "'°\\ ~.,, *
• -. ~ *..* ' *-.

~- ~::'..: .:' :--~-.*-*\\:':*_~:'.)g8=ses inthe clcywell and_pressuie*suppressiori pool,_and_to condense steam _irt the :.

• -.-,_* -~--,,*_* *,~._.,_::~_:.. :,

"~... :,:"

• c~ell followmg a*:LqCA in order to reduce the.temperature ~d presstire in

.

• _*: ;** ~~:~/.::*:;~~~:j\\,i~j!**;;~:~~- *:these *are~.-. :]ne;QcyWell -~pray.flow path p~ses ~ough the Drywell Spray -- '* **_ ' * :,_; * *.
• _:.:-* * ~ --:~_~(: );:--:~.:*:<S~;~~;,~~:: !*~~:yalve!i"to-=one--oft\\Vo':efght(8}inch spray* ririg headers inside tiie*n~elE _Th_e_*

-~*': "'- *.*:*- * * '* ~ o o*' -.;y--.*:,,~,. *;,"'(... '.. ~----~. .* ,~,,. '.,,. ~ **-: \\.. oo o ~ '/ ", '*,*',~ o A 0 o 0 oo 0 ~.. . : /-'.: r;*;*-:.:.~::. :::~~:*:::<~.':_/;>S,;:-!~~-f: Srippressior(PootSpray 'flO~'.path.passes _ilirough the*torils spray',valves to one_. ".. *~-. -.,. ~'\\.. _.. _ ~~

• ,! -~:*-"..; ** **.:::..-*-~-***,:'-:r."* J,.;,t-;

-~- ~ .* {-:: -:.~".:*~--::.. ;:,<).;-:;".::::;~<<:~-;.=t'~-r:jfoµr*(~) inch.spr~y#n.g**heaa~ratthe:top of the tqrus:- *:'.._,.

-_.- :** *.. <,-___ _:... ~, :.*....,_.

-~ :;.': ~~.-~::~~;.~:.~:~~f {~~:*:,i?2:1;~;*s;:~_::~>,_~- '.~ '< ~j ~-~~~ ;_,,~_,_-"'* ;-:~~--~~~'.~:\\:~-~--.. i> ~ *\\ -~, ~.:1~:- ~:'.r,=:/ -:: *.__ ~~ ~y:... ~:.- "Y >- :,,. :** :... )-....... > ---:<"*_-__ *:~:,_ ~, :_; ::. ~:_ 1 _ _..-.'._'.-_~.'.ef~~~~~~)~~~~~::~,;;:&"ffe~~if;,:* ~~7(;Thl_S:~Od<:?.'iS *assume~ ~o;be rp.aniiall}"~ipitiat<:?d te~. (1 ~)'niinutes after* a-."_*.._ '.,, ;

• c*.:._' _:

""t~ .,*.*j 1 (, t"_f.,.7.J **.,.

• ,'rJ..,... *..-

1 *** ! .,~ * , '/. ~

• l

~

• *...*. :.. ~ ~-~*':1§0 ;,/ -~-:!*':';'.'.°f:'?'::.;:~~~:'.:LOG-A ~wheri,tlie" d.iY\\Yell *pressure -is. gr* eater than :the'.permissi ve* pressure.(one {1)..

.;, : * "... ", ~ -."

• ~* *,*...

'::~ "\\;1.* ,~,_"::f.::.;:.-'~..,;~... ~',~.. :;:-:-.,J~~--~... *~

• ,, v*_;,.,,,..*

h. -

"\\.,...... ~~... ~,..-_

':.. -.;;.f.'*, _::;_~,:~*si:~~

'};:'.f:>>psigr: ~The* manual. initiation,: i~Micconiplishea 'by usirig* the'Containment initiation*... *-.. ". =...... ~-.. '-1.*r~*~..::.. ~~--*:-..:.1:)... ~.;:~

_;,.... ~... ~"':c.;:\\* -::..** -.*,,.*.--,._*'..'"' :'

• ~--

  • ...* *, -*.*. ~

~-* * * -*:->* ',-+ ~ 1 _,,.. :_._-.f/;_'..__.~{,~~f~*;, , "'.-:::r:F{~~~ :~~-~Ry~p,d.ec'.~ey!~c~* switches.:* In-thi~_.manual~Y: c?ntrqlled_ mode, one or~~-*,1:**::.. _ *.. "-

-. *: "f.,-~,:f*~~-f:1~f1H:f/1

-~~~twq\\pf the' two:p~ps in~eithei"of.the *LPCI Sy Stem division8 *is:required to-* pump* ** *.>>:_;,,-_.. _, *.,;-. * * ~ .. h,- ci:f~ ~~i p *. r *., ~-)- .., ~. _. ~,~.. ~., ~* *.,,__.. -~.* *

• ;: r.: * * ":" >~,~~~_,:<;:.'.:-t~~ *:;'A ---~"'~}suppressfoif.P,ool-wa'.te1Jhiough*the *heat..exchanger; where~it is cooled-by :the<<-.. :_.,.':::<~}-, > *? -: ' : :

.*' -""...,~' "°.;.-:-{-'* 1~.;:;t.:t.::.).".{.')\\,~... f:'i*-!.'::!:l."l 't., ~-*;:-'--t_._*-~'t*,..l.:,*°.',.*'-.. ** :.:'~_:"'. :,...... "!" *** ~'

• ~ ~

~ '*.L ** *,-:'..,. \\ '. ~'".,.**~ .-*~. ~- *. ._.".~, .- :~-:--*::::-::..:~~"~~~;::S-:;e.if-;,.*~ '*:;:;~s-w.~system~~an.d!'ftien:d1scha,rged-into.the: drywetnmdlo.r.~the~pr~ss\\µ'e,-:: _.: -~ -~~*~'~,.:; ::~_.:::*~:<<-- * . ~ ~- ...__;.;,..!~:;;;.-;,~-.. --~j..,!:~~:1~.;_~~::;:?1~~~- .. ~{:~.. ~-;.-:.. ::.~.'.t*-.::~;.,, ~ ~;..,,h. ;-,.':?'b*~.l ~~ ~=-:- --oa.. ~ ~-.", -;*- **;~;::.. :-~ \\*..,...,_*.. ~~ i=*t~ :1*::-:...,_.*. ..;-~ *~- -"1i¥~* -,... ~~-- : ;*,.,-. ~-~.:; ;,... /'.". ~t~~... ;. ~:::* :: -: -~- :-.~::.. /*. .,,.* "*'-"*'<.,-"',:P::r*,c.-.1-.,,._.,.:t:';;;suppresston.c am erspray.sparger.~"*"--,*----*---- -.*;**',~*,,...,-.,.-;-.. ;-..-*.*.,.~*,.,.-.; --....,. _,..... i:.;:.:~:~Jil:~l~i~~f~f~~~~~i~~ 1 f~~;~~~i~f~f~li~;~~~~:f;,~\\:;,. . ; ~,~;.:51~i:~"::'T:f~-:~~_;;-,;-~g-_:;~?f I)µrin,g~e¢e~ge~cy *operatJ.o!};:*tlie'Suppre_ss~on _Pool 4_Coohng* (S:p(;) mode,~-:*::-:;~<:\\:~"' \\",'.. 1 *.**. r* ~ "':. fn~~~~~.... +5-~..:~"'-' ;~*= &.~,,."'"2- =-*~11:*.. - ... *"*"'7 ** " ~ ~"....-\\.; ~:c. -.,*;,.t.~ .-:.~...Y:...........,,,_"'" * ~ *-"***;-.. .\\- t-.._~.~-:-i~ :.*,. :*"* v... 'i,, 7- * ~.~*::* *

• ~

1 ~..- *.!_._-1~: * .,, : *.;)-'.(~_--;;;;.r-~;-'::~\\-:;:.;:_*_;:t~ ~..:<'-::of.llie*~EP.Cl-system-,1s.. des1giied;.tcr'remove'reactor. core' dec*ay,heafarid sens1ble':~;i*-=, ~I"~<~*.-*:*;: *..

• ~";.!,.~\\.

  ':i-.;.;:..:::*j~*t~;;-:;:~~;,.:-:.:.... ~..............;*, ____.,:r,..

'**~""'.. ',,: ** **:.:c:;::.-:;; *. ;.. *}'..... -;\\........ ~ ~_.::... ~:::;. ,:*i:- .... *-~.- -.-..,,*****"'*,*'.:.i..,**~t-:*~,":.._,:**

• .. * -.-> > ~;:~~:,~,~~;.,:;;.~~:-L\\:<-~nieaffrom*$~_*s4pp~e~~1o~~po_ol.~fqllo~g *a:I~Ocw:-::Dufmg~aLQCA, the*decay* '">:*~:t~; >_:....

'. *_ *. '*:'>**:~*~~t::i"!'.~,:/~~~r.?--~:;t;~ ana:~~ilslble.h~atin:j}ie~'(6~j()f ste~,aild *~ater'.from. the -primrufteactor-'system"'

..

~~s~-. ~--.-..:. -:

• , ---

  • .:.. :_ :;: 8

-:!~ ~;'.'.::~~~~~-~tf ~;~~~~:'~~~-;j~~-~n~~~~~~~~~rk~1?-~'.i~-~~--~~£~i~~~-~9ij;~?~~~:,:t~---~~tatri ad_e_q~te ', -~-:,-,} =~-- -~~:* ~ -:-~*:-.~:: _*. . ~ -~*--' \\' ~~ *' ~:_:::"::;:;~ *i:\\;.:':;-?,~~--t~t~f,cor({cooliilg:. llie;discharged --watei)s :then:piimpeq froin:the suppiessi_oii'pool by._".';.. ~-:<-...:_~ : :: :-..- ~;:-,x ... :;.f)/~::..~~.!.. 7'"'!*~ -~----:, t~J*"*: -. 17**~.-,...,._*~.... * --~**7'-...:~"-*";.. ~\\,.... :..-:::::-:1. ~:1.~... :-..!

• ~.

_'.-~**,_-::.~;t/;:~~!~2:.,~~:~t;,~~~--~Y~~EC,C~~P1:i:m. i>:s~15ack~to'.the~i;-eactot-;:y~sse[~, In-thi~~µiq~e; *-one-j>f th~_-two=u~cr loops}_"> ~::<.-*.. *:* _ ~'**-.**.-.............,...... _.,.._,..yl'o~ _)........... ~ --***-t--"'*~-..;-

• -?~*,

~.: ;. :~:*::7~~"}_:~~-;<-~:;?~f:;;5%f~lt'"~l~a.fe.!aii~~4l9~P~P;~upp~~$,siq~~-i>'~ol *w~!~~~tfu~~gn-tlie:heat.-e?':diange~s~ wlie& t ~X--~.,~:~- '_.. : < :_~. "'1'...... j,*_'~*'"(j.'\\"'--.,_-* '1 *.f'i*;"~t°!,... ". ;--.,,"~,(."';:~".;:;... 1 *** f~.,.~,:i-\\*:><...,..~' ~lol-**1.,.,-' .* ~1-*... ,~_: -*.;," I

<: *.. _.:,..':~-~S\\~t~~".:'~~:vf;>~.-"'{:~~Jt~e,~~ate_i;1sfcoq1c~-a;Q)'*~the;,qc~W:-~ySf:e1Ii*and tlie~ -,r~turne_d-to.the_:s.uppression *::~* :~. /<-~*~;:: _.'.~, *

• -..,:;.a.}i,~"k*,\\,_'!":\\
• *..,rr; **

--~-'. '1..,:1*

• • .,._r.f'Y, _

_,,.,J >>~,,....,.. ~....... -.,::;-,:.. ~.. -. .,f.- -*~*=r. - p-. ~-..,~_.:...,:;.~>.::.-.:~-'C:~;.p"-:;,~~K~P.:~~:c~-.p' 06hma/ofieacfof.vesseF--'-:LBoth'p"*umns ilithe.'loop*. may'"*be used~fo:maxiinize'the>-~: -----,-:.-.- "* *' ~... :'2-~.,f:~~~-~=.f::~::Tu::__~:.;}"'~-.!...~~~~;. ~.:-*~-:*.. _c_*-~"'*~::i?>*:~

.~r:>.. ::-*J,.-'w.:*.~:.-,~::4~... :* * * -!S,. ;*,..*

~ -__ ; "~>.. * - ~ - ---**.-~-~-.. -~.*:**..-_*... _~~~ -

• "' _... ~-. ~ -:,:: :~J*'~'"'-> \\:*~ ~ ;

1;~*r:'c,,pootcoolmg;_Jihis*mode.~1s:m;m~ly.:.imt1ated ten ( 1.0) ~utes, afteqi'LOCA:'r*.- -~,,::,-:.::.".;-, '. : ~ *

• \\.*--';.Ir-,_.~:-:;:!

~,_-.,:_:.>; - ~. .: ~ _': :~., ~ ~;~.:~~'!'* ** -. 1 ~

• t'"{:*,***-,...,.t\\-

./ ;;': V-'"*** ~ * ~",.. .*. :*-:-~--~~-~:: ~-~-~:$'.":::t~<:::*v~JC:~f:when*.the mtwell:pressure is.gt.eater than the.permissive *pressure* (one. ( 1 }psig)::.,~._ * * :-_:.. *. : ~ \\,. ~- Jl.,_"" r' "\\ ~-*" ... if ,.I ,J t' 1, J_, , ~*

• l

\\ t\\

• .-.-.::";;_::it~~s~/:'Pi~_;<.,,-..:~-.::Tue.ma.iiuaLillliiatl9il'i~riccomplislied*.by \\lsing',tlie*contaillinenfimtiation Manwil :-.>."-

~* * ** -.~.. *1.. *.J.J~;"-~~~:... ::*11:~~: .~~~* -1.* "*-i!.**.:-.:~l.~*-=.)::';'".;:>.t.*.-*_;,j~~~:*{.*"~;jl;; __ ~-;... --~7-r.~. ---*:*'.F*,:_.-".,--:*"*:.... :~

• '::,-... ~-\\ ~. _.. ___.,,

.* ~.* l,,* *. *

• : ::~ *_,~:~::~~*:q~i~~',F.;i'.~;~;'"t.;{~q_i,P;Yegia~~k~r_l~S~.s~~c~~s~;:~~ qi~~lY:*C?,~~~Jle~ ~~~~:~s_;!,~qwred_:~~.~f ~~'.;:. :".~ ;:" _.: *=-~ -~

~-- *:*... /*;:~;,(:j_c:_:~~~-?t11f;;::?J.:.:-;;::d.llitiatea:Jol10Wfug-a$I:;OOAifo~liiiiirco1itairuneiit:pressuie *a:nd*teiriperattire 'to.*:-*. --~-..,-_ -* **

~~~~ti~1~:;~tl~~~~~;~~~t;~t~l~~~1:~S:f~i;~~2~~~~;s,. /~-;:;},;:'.~ ~;-.,;:--~*-* -~p~p,1a~.;~~.()QQ~gpm*~~thAlie*,W~~t~:heat.siril{Xaiid -~,~PJ'~~~sion_'po~~ ~temperafufe..,:~*; -:-,*_~: :~:. -~:..,. \\'-' ~ 'j'>.

• I"

-J,.;*

• _,,*._.....,.... '¥*,-
• ,.,<i._

0 ~ ...... /"f-*"'*.. *~ I

• • -..*~ :J.,,......,-*

1

• ' _.lj o<::.*. -

F __ :J.:**, :.**..... tr 't;J-7-S-:~_'.and:tw9Ri1x~c~w-.p~P.~3ats6oo *gi;111-_: :-D~sign 'ba5is:heat -removal Js -.~:- :~* ':~;'.~~t:i: ->" *.. * .;0 !:~'71::.*:d'i;;,a;,;:;;;.~t~-:r1~n*'~.;:'F='-':~\\:Y--'~*ttftli* ";.~::.;:.-R**"'c"*1'*'"li-""';:'."',~t~~r,.;,,;L";:~=~~~...,:2*~a'"~;-.::!'**...1** "'---~:r.. a",.;.t:~*:}~lli--.,-:,:;,~;,.-:,;;',-,,,_,1- ~:*?" !_ci';J_h,,: ~ aseumm OLCU>: OWiuuOu~~ e;.u _,,

• ea :.excua.u er.an *:is;1nue en en °01-,

e.-~*;>.;r;':'.;;*,~Tst;"_.'<:::.,.;.,. . ~:

}~{

c"-"7;~~1 "*'"'-'~~~~-..,~,:_-.~,~,.--J?~f.~

.~. . ~*. . :. ~-~... ~ "*f::~.-,...*: -ATTACHMENT :A BACKGROUND AND SAFETY EVALUATION OF THE PROPOSED CHANGES

• A diagram of the S_µppression Chamber ~s presented below, outlirung the*

~-.systems' key components._. '~ .._..,.;~:.::* :,, ~.... ~:...:.....

• • .~:.*-~:::~~~~ ~~.... *.. ~:.,.\\.... ~*

~* :S', .. -~*. t'* ._/--*

• -~

.\\

~- ~ :.\\.

,:0

~:_.. 11

• • -~:

.. _. ;:': *i.* *.. 1; r ~~- 't..*. : *- -:_:_-. ~~-/:. ~.**:. *. *.. **..,. .~. :. :; _*.,,.. -~ _:*':~2~~;.~,Jtf

• f~ffJ"!:-'lf,~-- ~::r,.FI,G~-~-*~* ~:SUP:rl:IBSSI~~.-CHAMBER DESIGN**.. _,... __.:. '*' * ~

~~'.-1j:~\\f;~{~_"";-~:~~~t.~:~?2;§:;f'.{.~~-,:;.~-~-;,~J:/~!:*;~:.::f~?-'~~i:~-.~~(:~~~{<.-.1:c:~:.~.:-_.. <

• > *--~- **.. -. ___ -: "'-_-< ~-

• .*;~-.. *._

-~*.* --~;_,'.*

• -/~:.. ;,:~_f:,::.:::'j:z,r.>>,-,.*-***::.::*-"~~::a.'::::>:,,/.':: >>:_;::"..;:J)ie eleva:t:J.on. of:Ui~£or~_ Spray and LPCI pump cent~rhpe.ts 4 78.1 feet. *

,.,_t~..,...- *

',~-l'l

)7 .,,~-;..- !'°-,~ ~, **- *-* **} ~ "* * ~* 'J I _;_;; --~'0,;;,:';;:J.7.'fr -~;-~'>(..:-:.: :The:"ritiniinum ~uppres:;;ion po'ol level *elevation, assuniing a.maximum.draw-down -- .~...... !... **- ~-- .l-....... ~,..... -- ~'

• • ~~~~.1~;~.:~7?~':-

~,,;.~*~~:of:2::T.feefis'49.E4'feet:for shoruerni.NPSH*caicUlation:-<<A:ara:w down recovery':- : *:: - -:_ ~ - .= 0."':~.:~t~~g-~ ~;.>~{-~'..:i:~...-()i;1j;feef.f~*;~redited~t~siiltin.g.'iJi:a net *drawdoWri of 1>>foot' (492" feet) for the-long*-.:::*.*-: I

~-... :,

- ~. ' ' ... :~... -...

• • .i.'. -

.ATTACHMENT A .. 'BACKGROUND AND SAFETY.EVALUATION OF THEPRO:i;>OSED CHANGES - . -. **3.3

• .CHRS Parameters -The following section provides a summar)r of

• .:the.key Co~tainment _Heat Re~ovarSystem Parameters presented in Table 3.1, *
• _. '~Description of Current Requirements.". The scope and content of existing plant

.:. '.. \\ ~*pai_ameters are aff~cted ~.aresult of the reconstitution.efforts directed to resolve .. ' *;existing' concerns With the understanding and demonstration of the system design,.. 1 '** ~;, ::, ;f .:)*~.~--:;,'._'and Jicensing 6a51s. *These P¥ameters need to be examined to ensure plant sefety * * . '.. **~

• • ,;'~'ii :*\\*:\\,~.:-+**:::'.:.J;~>*:i.:-.::::.':.::4~.:;and requires. the highestEGCS flows over.. the long term... Smaller break sizes are ;...

I~~~~\\~#;}.~F;l~&:i~~.~~itJ~:J%i~J~.~:r:::;!::+/- 1 ~:i:!~~!'";;e~;.ttl~s~~~e, *. * ** **. -_ ~*::'}~;(,?:;~;~>>;'.:-?:~:~;L.:)~... ;-: './DBAcas~* (see UPS.AR F.lgm~s 6.2-33;:6:2-34,-i>'.2:-36, 6.2-38 and Quad _Cities.* *.. -.*._ ... *~. **. *

1~~;.. ~: *'~~~;::.;~;:::~~: ~fj:.((:~"~i~?:*,,=tJF,~AR;*Figur~'.6:2.: 18):;'..2)':Non-c~~densable. trfilisference occills rapidly* in the :~: * * ~ * ** * * *.

~:,~--:;?*,t!01~~~{-~Y-;.::'.:.:~;.:'/:~:*<1*~~ffiai1est',break*si~s:-~-wlii.cl1*e~siires *containlnerit overpressrire~is' avai1~b1~*roi n~t -~ ;, -*~~-~?~~~2;J~~~~~:~,i.~:~;~):,*~;~~*~;:rf9'S~.t~y~*.. ~uctig~J1~~~{~J,;Y~s.sel bl~wd_o_~1rtime:increases.:With de.creasing b~eak - _ * ~ * 'f::.*::i.<.* ~:?::,~:~,._*:: :."...-.";:~:::~~.,,,-~S-~:;~:size;<1ijtµtirig<<the'.tinie,,a(which ruriout conditions could occur, particularly in *the. * * "_.~~:., :'.

,_~_

J!S~ :iff;~~;:~'.Zi/:::~;Z~ifil.1Y:~i:>l1asi~:9f tjie:*e~i~~;~ruid _~) s~at(br~~s'Wiil experience~ refili and

~--, 0 . -~ *. ~-.* : : :* ~~ .::';J°:_'.L~!:~~~iz~;;:~,_,;:.;~~~ pr~~~Ud:l.ation~bf the~vesset *precludirlg iuriout conditions ror* the core.spray*. *..-. :.. -:

• -~I;1s:~f ~1~~Jf :W'~'.i~:r~!~~ii1~i~~~~~~~t:~;r1vi;E~::j;:s: ~:;:~]! ).**..* *
  • • .*~" :;;:*:'::.*::::~*:.>:,-:_-::":~;;:?*::_\\;:5;:Erhergeri~~'Diesd:Ge~er_atorJ~Jirriitl.ng in.t~Qlls.ofNPSH ~ue to the limitat~on5:.*

~:~*.~~j

~ ~ *-~:.~ ~'.. *~~- -* ::'.. ~* * -

i

:~-,'j,,_p,y;.;;:;),::. ~\\c.'i,:;-~"'f;,:_,:t:.~~-::;:_;;$'-:?.: ;,?3 :3~f.*;:Dijfe.re!'lt1al Rrf!ssure.Jor BPGUC,CSW is 20 ps1d, - When CCSW is __.

• ,....-V,:lr.* *.;.;..-- ****...,.,
• .:j!*-.,,n~**

~'->~\\::...;-t *** -:... ~ ,.-...~. *'-l'"**..,, .;,*-\\,..** ** "~*:...**1':* .,,J~-.-- \\. ?::.~./~ *~~tr.-;:;L**:t~?~~~t/:~:-:+/-.:-floWirigAhe_pressrite=oi{ilie.. hibe.side of ~e* he~t exchariger.is maintained 20 psid \\ "i"'* ,;.l'".. f*

t:.

_.,.r~

• ~-_,

/J.,. >C .,t ). -~ >r

• 1.---*

~I (I~-: --:-? ~:l;}i_~:~( ~:~~~~: :) ~.d??~ ~~b"ove ~e J)i~ss~e _pn ~~.:Slietr_sioe,10* pre~ent :shell *side.water. lea!cage* into *the. *.: * -:~!.~:;~~~;~_*:*:;;~~;:.. :~:*~';_:;~:~>7~~:~':rs£~~~~a~~~seci~eii(~s~~~ge*:tq.. the*~~~r_ by* tfu:?hling the.cc.sw ~scharge.:.

• ~;.'._;;~}:~~;~~ ~i/-:~::* ~:r:-;~~./:;,~~:'.::valyeJocated 9~ th~.<>4tlefof the LP~l heat ~xchanger. Instrumentation i~... *,

.;.*(~*iY::.-~.. ~~i-~~-\\~-:~;~~~<~-~~~~pro~ideift~)moruto.f*tiie.:Af> beMeen:the~LPCI heat exchanger nibe side and shell. ~:; *. v ___ :.. :~7... '1:'.:.-:-~:.:.:'.. -: 1 *~::.~~'f.. a:..~.. r~*~**.~~-.. ** *.. -----:~*:'*r:*.';_*.~~: :..~*::-....... ~*..:,. :*,... - *>**. {"~--.:.* .. ~l-*....

?> ;~:~~t:i:'.:i~f*~~;>;:~~~~z.: ;;:~ ~>:;s~de. :~Additi~p~al:EP~the~t ~}{chap.ger ~es1gti inf ormatlo.n _1s prov1d~d *m.µESAJl.. *:

i~~!~~;~&~:i:~~f:i1~~~i~;;~~~~~f;~~4f,;Y~fa,::~?,/'.< ;,b~'.) *.* *, ;. ~.*. *.. * ~-;:;~~-"~~:-~::'l.Y:'.i'*::~=:-;*:*:-:

1l';__;Lt's'.

:1z:.::-~:-~-;-~.;;,qq_sW:§u~~~te"':

1F1ow--.-Nom1'f!_al r56QQ gprri},,..A*nommal two '(2). :.

• ~.... -..,.,-!-='l*'f*~£-:---.; **.,,K"... ~***.i-~

~-t"",V""**- -~..... ::.::*_-*....,, ---1-::-- .~-*-., r -~t'::z.:-,:,~;;~;::;3.'*t::.:~~~:::_.~._,0d*fc":::\\GP~-:W;R~P*:(IQW~Q(?6QO_ gpm_ attllt_~ate heat 0sirik and _suppressmn pool-:\\'_:.-:-_. _ _ :P;&l,,~~~~~t;.~3:;:~~~:~f.i;*::}'~<:ii:emperafuies::0(i5~1s~til~ea '.irillie. ~~~ni.-Hcefisilig b~is:,.The iecoilstituted -~:" t."-*-r_.,. ~rr** ':;:,f#'*;'**~.r'*.~...:~* s:-i-.-;

• -4'.. >\\;:
• .-*--:~*---*.!...,,,;*,<

1 ' o~-- "'.il'k*';-. _;o. .. ~~1:i¢:9f-}6<!Q1fil>!ll.'.for.,~~Ji~p~i~.:_rie~~~safy. to *~~tain t_!ie required pressure.

. -'",*'" ~= *.:. AITACBMENT A BACKGROUND AND SAFETY EVALUATION OF THE PROPOSED CHANGES . 3.3.4 ECCS pump flow requirements (CS 4500 gpm - nominal)- Core Spray rated flow of 4500 gprri is based on UFSAR 6.3.2.1.3.1. Based on UFSAR 6.3.2.2.3.1, this is greater than the flow rate necessary to maintain water level

• above 2/3 core height - long term. A Core Spray minimum flow rate of 5276 gpm per pump for the first 200 seconds, and 4SOO gpm per pump after 700 seconds is

~utilized as the basis for the current 10 CFR 50, Appendix K analysis. 3.3.5 *ECCS pump flow requirements (LPCI 5000 gpm - nominal)-The total LPCI flow rate of 5000 gpm is required in order to achieve the required LPCI heat exchanger heat removal rate. This flow may be split between the

• drywell spray and pressure suppression chamber. However, the containment heat

.,removal is only dependent on the total flow rate and is independent of.the flow split.. A LPCI flow rate of 9000 gpm ( 4500 gpin per pump) is utilized as the basis for the current 10 CFR 50, Appendix K analysis for Loop/LOCA and loss of an EDG single failure scenario. J.3.6 Instrument uncertainties (not inCluded) - In accordance with the Instrument.Setpoint Control Program, uncertainties are not accounted for in the design basis of the long-term* pressure and temperature response of the CHRS: '3.3. 7. LPCI *:neat Exchanger lerformance - The original rated duty of the LPCI. heat exchanger was 105 x 10 *BtU/hr at rated conditions. As the result of an effort to reconstitute the basis for this duty, in the absence of the original ba5es, a value

• of 98.6 x.106 Btuthr was established (Reference 26)~ The reconstituted duty has
• been utiliZed in the operability evaluations and previous License Amendment Evaluations (Refere~ces (18), (21), (22) and (23))... The heat exchanger rated duty includes a 6% design plugging margin. Additionally, some of the original 70-30 CuNi tubes have been replaced. by AL-6XN tubes which have a reduced thermal conductivity. To ensurethat*other design basis evaluations are not invalidated by
• replacement of these tubes, the number of tubes plugged or replaced in each heat
• exchanger will.be lirllited such that the total reduction in heat transfer capability will not exceed that which would result from plugging 6% of the 70-30 CuNi
• tubes. *This is discussed in UFSAR Section 6.2.2.2 and Figure 6.2-42. (See Section 5:2.7 for further details)

J.3.8 Service water inlet temperature is less than or equal to 75 °F-Technical *

Specification (TS). Section 3~4.8.C provides the requirements for.the Ultimate

. Heat Sink. TS Section 3/4.8.C specifies a limiting condition-for operation that ... ~ ~. - service water inlet.temperatureis_required to.be less than or equal to 75 °F: This -.::~*.:-:-.. ::, :.*.... *.. limitation.ensures that the input assumptions and initial conditions for the plant ..' :'*. ;.. : safefy analyses.are maintained during normal plant operational conditions. The .. '"'.. - - :~~--:: * *:

. currently operating Technical ~pecification limit which requires that the.

~... ---~

~!.1!.t!.. ~_~_-... -.i.*. r_i... f_~:-.;.***-~.-.~-*-{1£_J1~~Q[*,~.. '!t*"i.* :.*::.. ~7

?[*.'.:_--.-_ *. * **.. :. :>£j~~* C~-" c~. ** * * -~ - : .~;..... ~-

~/~-;~i~:-_:*:~r*:i.;,:.'~,:;-><*<*\\<~

• 4. -

ATIACBMENT A BACKGROUND AND SAFETY EVALUATION OF THE PROPOSED CHANGES temperature he less than or equal to 75 °F while the plant is in operation was proposed for approval and subsequently approved by the NRC staff in References ( 18), (21 ), (22) and (23 ), respectively. 3.3.9 Maximum average suppression pool water temperature limit is less than or equal to 75 °F-TS Section 3/4.7.K provides the requirem~nts for the Suppression Chamber. TS Section 3/4.7.K specifies a limiting condition for operation that suppression pool.average temperature is required to be less than or equal to 75.°F. This limitation ensures that the input assumptions and initial conditions for the plant safety analyses are maintained during normal plant operational conditions. The currently operating Technical Specification limit which reqUires that the.temperature be less than or equal to 75 °F while the plant is in operation was proposed for approval and subsequently approved by the NRC

• staff in References (18), (21), (22)and (23), r~spectively.

3.~.10. Peak Suppres~i~n pool Temp ~s < 160 ~.F This lumt was confirmed for .NPSHpurposes as.discussed below. The basis for peak suppression pool temperature-post-LOCA is not explicitly provided in Dresden's FSAR for any LPCiiCCSW pump combmations. In reconstructing the peak suppression pool temperature that would have been used at the tinle, a value of l70°F was .* estiniate_d for the* 1-LPCl/2.C_CSW pump case based on the following: Quad Cities h~ smular. ECCS flows, heat exchanger capacities and heat loads to Dresden; therefore*, Quad Cities post-LOCA r.esults can be employed to provide a reasonable estimate of the. Dresden peak pool temperature. (Figure 6.2-18 of the . *Quad Cities.FSAR provides a Case (d), which yields a suppressio~ pool. inaximum temperature qf 1.68°F for a 1 RHR/2 RHRSW pump scenario. This scenario is comparable io the Dresden UFSAR Figure 6.3-80 c~e. Since this case was* based *on an initial pool temperafure of 90°F, and there is mention of a 95.°F -initial pool temperature iri the Dresden Tech Spec bases 3. 7 A, an adder of 2°F is used 'resulting in a Dresden peak suppression pool temp.erature estimate of 1709F. The 2°F adder is conser\\1ative and supported by subsequent GE calcul~tions which show.a sensitivity *of approximately l°F for a 5°F change in ~tial pool temperature._ *

• The Dresden FSAR, *states the followirig: "'The maximum suppression pool
• temperature for a design basis accident woUld reachabout 170°F.
• -The Dresden FSAR,. page 6.2-'.l 7 includes a discussion regarding LPCI heat exchanger sizing: -u *states "that in the event of the loss of coolant accident the
• terriiffiai s~ppressi~n-pool temperature would not exceed 170°F.".

~-:*~:.~.- _.;*~- ... ::**~;-~-~--,.. *.... -.*:**,-.:**~. *'*... --:. _:_. __ --~ -.. ~:~>.-.. *~ ~--:~:~*_.:;:~; __ ;_,:,. ~--....-. ~..... ~:. ':*.. ;' :..... . **... _;.~.. j*;.:._~-:~.---... ; ~~---*~--;!_.~_~:*:*

• ._:~..

~*-*

• -==~

.. ~.::;~,_:J--:~

. *~ .~.....

• * *Jo*

.. ~ AITACHMENI A . BACKGROUND AND SAFETY EVALUATION OF THE PROPOSED CHANGES After discovery of the increased ECCS suction strainer head loss as discussed in Section 3.3.19, the peak suppression pool temperature was limited to 160°F by limiting both the maximum suppression pool water temperature and Ultimate Heat Sink inlet temperature to 75°F (References (18), (21), (22) and (23)); 3.3.11 Equipment Qualification (EQ) limits -The Equipment .*Qualification parameters are discussed in UFSAR Section 3.11. The. following zones in the Reactor Buildmg Basement and ground floors are potentially .,impacted by higher long--term suppression pool water tempe"ratur~s. Zone Existing Post-Zone Description LOCA Temperature 2 135 Torus Area 3 114 RBEDT Rank Room 4* .185 LPCl/CS Corner Room 5 185 LPCI/CS Corner Room .. *10 104 Reactor Building Ground Floor JI 104 Reactor Building Ground Floor 12 104 Reactor Building Ground Floor * .13 104 Reactor Building Ground Floor 14 104 Reactor Building Ground Floor 15 104 Reactor Building Ground Floor ' 16 104 Reactor Building Ground Floor .. 17 104 Reactor Building Ground Floor 18 104 Reactor Building Ground Floor

• 3.3.12 Maximum Containment Pres;ure -Long-Term -The maximum
• containment pressure for the long-term post-:LOCA conditions are* currently
• presented in the UFSAR for-a limiting DBA.

. Pressure*: Scenario UFSAR Section

• UFSAR Figure Drywell/Suppression

.Pool .DBA 6.2.1.3.3 6.2-19 1011 psig @ 600 sec, 8 psig secondary peak ~- * *.

• f -......
  • ,.For hm1tmg DBA case there 1.s no d1stmgu1shmg between Drywell and Suppression Pool
• *Pressure.*
• .: ~ *:* :. -'> ""'.,;:;\\.0 :: ~-. <.,>.~;_:... _.:~'

.*.. *~ ~ *_;~.';.~_ - ,~ _, __.......:...r..:...~ ** -

~.*.

• *1

~*........

I-, A'ITACHMENT A BACKGROUND AND SAFETY EVALUATION OF THE PROPOSED CHANGES 3.3.13 Maximum Containment Pressure - Short-Term -The maximum suppression pool pressure for the short term is currently presented in the UFSAR for the limiting DBA. Scenario UFSAR Section -UFSAR Figure Value Limiting 6.2.1.3.2 6.2-19 48 psig - drywell DBA Approx. 27 psig* wetwell * -* Calculated during original design: J.3.14 Minimum Containment Pressure -Long-Term - Minimum long-term containment pressures were calculated for use in the LPCI and core spray pump NPSH evaluation. 'These pressure are shown iif.UFSAR Figure 6.3-80 and - described inUFSAR Section 6.3.3A.3. .3.3.15 Mi,iim~m Containment Pressure - Short-Term -A single curve of -containment short term pressure is documented in UFSAR Figure 6.2-19 for the limiting DBA-LOCA., No representative containment short term minimum _pressure was documented in the UFSAR~ 1.3.3.16.Credited Containment Overpressure (2 psig-Short-Term; 0 psig Long -

• Termj ~ As described in References ( 18), (21 ), (22) and (23 ), credit for 2 psig of

.containment overpressure is taken-in the short term(~ 600 se~onds) and no credit -for containnient overpressure is taken in the long term (> 600 seconds). As discussed in Section *3.3.10,*limiting initial suppression pool water temperature and CCSW inlet water temperature to 75 °F, respectively, is necessary to preclude. -.the need to credit overpressure for the 19ng term. -Afte~ the higher ECCS suction strainer head IOss was discovered, both the - -maximum initial suppression pool and maximum CCSW inlet temperature were limited by the Technical Specifications to ensure:that no long term credit for - -* contalliment overpressure was needed. In-the.short term it was determined that 2 - - psig of overpressure is needed to demonstrate adequate pump NPSH at flows

• necessary to meet 10CFRSO Appendix K requirements (References (18), (21),

(22) and (23)). * -~- .. 3.3.17.NPSH M~gin -i.ong-Te~* - "UF'SAR Section 6.3.3.4.3 and Figure 6.3-80 _

.~: ~-~-' *.. -,. :>.

--. d~monstnite that~-with containment pressure at 0.0 psig, sufficient NPSH is ..

• _ iJ -.
• ..aval.lable for the LPCI and Core-Spray pumps at-rated flow with no credit for

_*. -.,,?::~~-~-}.::. "-~'* * *: * : __,-,' :;containment,overpressure.. With the increase *in head loss across the ECCS --. ":: -T+:~::_:,:~.: ~; '._:-~:' :_. -.. :' -s~er suffiCient NPSH.is a~~iable long-term provided that the.operator. ,~.

. ATIACBMENT A BACKGROUND AND SAFETY EVALUATION OF THE PROPOSED CHANGES throttles the pumps and the initial suppression pool water temperatures and CCSW inlet (ultimate heat sink) temperatures.are limited to 75 °F. Operators have been trained to recognize cavitation conditions and to protect their equipment by.throttling flow if evidence. of cavitation due to inadequate NPSH would occur. The control room has indication of both discharge pressure and* flow on each division of Core Spray and LPCI. The Emergency Operating .

• Procedures (EOP' s} pro~de guidance to maintain adequate NPSH for the Core

. *

• Spray and LPCI pumps. The NPSH curves proyided in the EOP's utilize

. suppression pool bulk temperature and suppression pooi bottom pressure to allow the operatorto determine maxinium pump or system flow with adequate NPSH. These curves are utilized.as long as the core is adequately covered. The ability of

• .*the pump to withstand at least one hot.ir of cavitation Without damage is discussed in.3.3.1 Rbelow..

33.18 NPSHMargin -Short,;Ter.m - NPSH margin for Cor~ Spray in the short '.term is* in the. clirrent UFSAR. It c~ be inferred from Figure 6.3.-:-80 that . adequate NPSH is available for rated flows. The* inaximum suppression pool*. water temperature and consequently, minimum~NPSH available, occurs during

• ~. '_':.. '.: :long-tenn conditio.ns; *...... *.

.. *. ~.. ... * *' In the.' analysis ofLPCI anci Core Spray pump p'erformance at above rated flows, >:.. ** including>.th~ iilcreased ECCS suction strainer head loss, it was determined that a _minimwp of 2.0 psig containment overpressure and maXimum ~tippres~ion pool water temperature of75°F,was necessary*to ensure ad~quate NPSH to allow* pump flows riecessary to* meet JPCFR50 Appendix K analysis reqllirements .. during tlie.shortterm contfilnmenfinjection phase.. ~.. ~ '*:~ _'"::., *~,; ~ A*o

: ' :Even W<lni6-eclit forthe 2.o psig, so~e cavitation wiil occur in the short term:. *.

. * *-. '. This cavitation-is considered acceptable based on testillg conduc~ed by the pump' vendor as described below _and analyses which demonstrate that the *core *Spray ... *. and LPCI pumps will.provide sllfficient flow to meet their ECCS functions.

• * * *As part of the' orlginai design of the plant, the pump vendor perfonlied a

... cavitation test on :the.LPCI pumps (a Quad Cities RHR pump was actually used). . * *. The Cavitation-Test Report for Bingham 12xl4xl4xl/2'CVDS pump . - '. :demonstrated no. evi~ence of any daniage.to the pump comp<)nents from.

.... cavitation with at least one hour of operation at the cavitating condition.:

. -.. *-_... ".'.,... _. '*.*' _ *. This analysis was* reviewed witli respect to the Core Spray pump *a.na the resUlts .......... -~:-:.-,: '.. ' ~ *..

• detemiln~d to b~ applicabl~::Jbe ratio~e for this dete~tion is:
• ,*~~~: __

~.-:~*:=*. ~'.;

ATI'ACHMENT A BACKGROUND AND SAFETY EVALUATION OF THE PROPOSED CHANGES LPCI and <:ore Spray utilize the same impeller pattern and therefore, same overall characteristics. All LPCI and Core Spray pumps have tested NPSHR curves that are essentially identical (within 1 %). The NRC in their SER dated January 4, 1977, found NPSHA deficiency to be acceptable based on an analysis and test data in the above report which

• . demonstrates that LPCI pump damage would not occur. A subsequent review of this analysis and.test data was performed by the NRC as documented, "Issuance of Amendments to Resolve an Unreviewed Safety Question Related to Emergency Core Cooling System Suction Strainer Pressure Drop" (TAC No M97696) dated

  January 28, 1997. (Reference 23)

'. : *3.3.19 ECCS Strainer Head Loss-The UFSAR and original installation drawings ~ ... *. *. * * * * *.: * ~-.* *_* :*: * * 'identify a one (1) foot head loss across the strainers. The one foot head loss . across the ECCS suction strainers at 10000 gpm clean is documented in UFSAR ,.'.Sectipn 6:223:2. *:_ComEd recently discovered a calculation that had been. * * * > performed bya vendor. This calctilation was identified during design reviews in' support ofthe installation of new ECCS Suction Strainers (resulting from actions '* * < * * :_.' *.:, *.' -~"

• -which are befog taken in response to IEB 96-03) after the calculation was

~.~- ;: *, :*:.. **-< ~ * '. ', identified as a reference in another design document. The 1983 calculation was.

• • ~ :._ :'.. ~-.. ;.: : *prepared.to assess the structural adequacy of the strainers as part of the Mark I :
• . ; * *, ~ * *. *. containment prog!am: The calculation detemlined an actual 5.8 foot head loss at

._*. * -. *. *' 10,000 gpm across the clean ECCS Suction.Strainers. The reconstituted head loss ., ** *. '*resulted in the*reevfiluation ofNPSH as discwsed in Sections 3.3.16, 3.3.17, '~;.....,, : 3.3J8, and References (18),:(21),.(22) and (23).

• ., :-, *: *:~. '~'-:::.. : -~ :**: '": :~ '. T~.;dc~un~-fo~.stramer plugging, the current.licensing basis for Dresden assumes

• *:'.. ':::*~. /.':,_:, *:-one.of the four ECCS strameiShdOO%~blocked while the remainiiig three.

.. :*.,, ~::>~,*-.- :" *:_.: _:.,*:<strainers assumed to be clean: The 'strainer assumed to be blocked was chosen for ~ ~*. *~~.. **. *:*. - * : --. * ** : rli8ximum eff~cf on both LPCi ~d Core Spray head losses for all pump ~-

• -*~-*

combinations.. < **:'.r7..,.

• ~-- 3.3.20 *May-Witt Decay Model - As noted in Dresde"xi UFSAR Table 6.2-6,

.. *>.>.,_-*:-*~--:~,-.. *.. . : ' ':S~ary of Dresden Umt 2 and 3 P()ol Te~perature Response to SRV

• ~ ** ** *.. ~/-..:* *:-.. : *' *.. *,. Transi~nts; the.containment heat removal analyses.utilize the May~ Witt decay. *

• • • . _;' 0.-:_:*:

~-::::-_ *.::~-~::.:: heat curves~- The original design ~alculations and corresponding input

• ._. *: * :* : ** _' ** _,".*:~s~pti~nS.for the CHRS at Dresden Station are not readily available: However,

• • -: ':-,:: :,:~*~~:~'*:-.:~~ :: :,,*_.: ::

~--*~ fo(plants' of a similar vintage to Dresden Station~ the May-Witt decay heat. . ~... -~:- ';:**/_ -~~~7-;t.~:,;,.. :z.:,-.~: ':.c~esw~e-.wed as the model for:deterinining adequate containment heat.. .. :-... : ~ =*.i'~~~--;7'c..;{~._~::*;:.>::- ?~., )emoval.characteristics. *The M~y-Witt model provides a conservative '7~*~:~_:.... -~:-~- ?f~~*.:~-::<<' *t~:.::.. representiition of the fuel de~y heat following accident conditions. ~.. : '. -~ - '.

ATI'ACHMENT A BACKGROUND AND SAFETY EVALUATION OF THE PROPOSED CHANGES

• 3.3.21 Condensation stability criteria - Dresden is equipped with safety relief

. valves (SRVs) to protect the reactor from overpressurization during operating transients. When the SRVs open, steam released from the reactor vessel is routed through SRV discharge lines to the suppression pool where it is condensed. _Extended steam.blowdown into the suppression pool, however, can create temperature conditions near the discharge location that can lead to instability of the condensation process. These instabilities can,.in turn, lead to severe vibratory foadmg on containment structures. This effect is termed condensation oscillation (CO). This is mitigated at Dresden Station by the usage of quenchers at the end of the SRV discharge lines, as well as restrictions on the allowable bulk suppression .. pool water temperature, in order to ensure that the local pool temperature stays

withiti acceptable ranges. Technical Specification Section 3/4.7.K provides Limiting Conditions for Operation and Action requirements, regarding the suppression 'chamber temperature.

As noted in the Dresden:UFSAR, a plant-specific analysis was previowly

• performed to determine the suppression pool temperature limit for Dresden.

. *uFSAR Figure 6:2~3? shows the resulting local pool temperature limit 'for*'

• Dresden Units 2 and 3 as a function of reactor pressure. UFSAR Figure 6.2-39 shows that for plant transients involving SRV operation during which the steam 2

.flux.through the T-quencher perforations exceeds 94 lbm/ft -sec, the suppression .'pool local temperature liniifis200 °F. For plant transients involvirig SRV

• operation5 during which the steam fl~ through the T-quencher perforations is.

2 ~less than 42 lbm/ft -sec, the suppression pool local temperature limit ensures 20 °F subcooling'.

• '* >:.-:.. ':. _: --. : *. The Dresden: T-queii~h~1i are. submerged in 9.17 feet of water corresponding to

-

... * "-* -: * -- *. *- 18.53.psia:-'The saturation temperature at 18.53 psia is 224 °F. Thus, to achieve

• • .. * *.. *:... *. * *. -'.. 20 °F subcoolmg the local temperature. lllnit'with a steam flux ofless than 42 lbm/ft:2-sec is 204 °F. :* * ' -.. *<..._ :

.To demC>iistrate-that the l~cal suppression pool temperature limit is satisfied,

• seven limiting transients involving SRV discharges were previously analyzed.

_.. Dresden UFSAR Table 6.2-6 presents a summary oft,he.transients Bnalyzed and .... -~ ~ '.. _. -. ' '...... :... *the corresponding pooltemperature results. Three of the.transients conservatively . assumed the failure of one CHRS loop, in addition to the single equipment ... *<.malfunction oroi}erator error which initiated the event. This conservative ... '.:.. ::.*-.* *~ ::'.. ~-'*":::>:',' :assumption exceeds the-current licensing' basis for anticipated operational

• ~*.... -*~*:> -.:*..

-.~':=~--~-:~**_transients*.*.

--:~J-

---~- *.*- ~.... '.. -. -_*.. .... ;.. -~. ~-...... *-...

r -~--:.. *.: ~ *... ;_ AITACBMENT A BACKGROUND AND SAFETY EVALUATION OF THE PROPOSED CHANGES The notes to UFSAR Table 6.2-6 list other initial conditions and assumptions included in these analyses.* The analyses ofUFSAR Table 6.2-6, Case 2C, normal depressurization at isolated hot shutdown, shows a maximum local pool temperature of 153 °F. This demonstrates that with no system failures anti in the

• event of a nonmechanistic scram, depressurization of the reactor pressure vessel via* SRV s. at 100 °F /hr results in local pool temperatures well below the condensation stability limit shown iri UFSAR Figure 6.2-39.

UFSAR Table 6.2-6, Case 3A, a SBA with one CHRS loop available, results in a maximum local pool temperature of 180 °F, which is below the condensation

• stability limit of 204 °F. The local to bulk temperature difference at the time of

. maximum local temperature is "26 °F. The maximum loccµ pool temperature of

• other cases also remains below the condensation stability limit throughout the
• transient To ensure adequate monitoring of the suppression pool temperature, the Suppression Pool Temperature Monitoring System (SPTMS) was installed to monitor bulk pool temperature. The SPTMS is described in UFSAR Section

. *6.2.1.2.8... By letter dated March21, 1995,the BWR Owners' Group (BWROG) requested the NRC staff.review and approv~ GEreport, NED0-30832 entitled, "Elimination ofLirillt on BWR Suppression Pool Temperature." NED0-30832 presented a

• discilssion.oftest data and analysis that supports deletion of the requirement to maintain the local suppression pool temperature 20 °F *below the saturation
• temperature c>fthe pool during SRV disc~arge.*.

33.22 Operator response time is credited at 10 minutes following LOCA -*The

• .current CHRS accident analysis scenario iricludes the assumption that.manual

. control room operator action is necessary at less Uian or equal to ten (10) minutes

• f9l10Wing initi~tion of the design basis accident. * *.

. Table 3.l: DESCRIPTION OF CURRENT OPERATING PARAMETERs

• PARAMETER DESCRIPTION 3.3.l Assumed Limiting Accident 3.3.2 LPCl/CCSW AP 3.3.3 CCSW Subsystem Flow - Nominal
• 3.3.4 ECCS Flow - Core Spray (CS) - Nom~al..

PARAMETER Large Break LOCA 20 psid 7000 gpm for NPSH, *5600 gpm.to

• maintain LPCl/CCSW pressure differential 5276 gpm for first 200 seconds 4500 gpm after 200 seconds 3.3.S.ECCS Flow - LPCI -Nominal 5000 gpm

. :.{~-:-:"tic~::~~If _: * '33.6 ECCS (LPCl/CS) Flow Instrumentation Uncertainties Not explicitly accounted for -~~ *.. 3.3:7*LPCI Heat' Exchanger Perfonnance 98.6 xlOUBtu/hr@ 10,700 gpm LPCI -"!...:." - < :* ~- ~._ - _.. ~~,. flow and 7000 gpm CCSW flow "If~! !~':i 3 -2~g~j~*~~~i'~~#i~:.~;1~{~;;:;,";::: *. : : ~~;~,.;.. :::,~ ~,.,.. * * * * * ~*-.

AITACllMENT A BACKGROUND AND SAFETY EVALUATION OF THE PROPOSED CHANGES 3.3.8 Maximum Service Water Inlet Temperature 75 °F 3.3.9 Maximum Normal Suppression pool Temperature 75 °F 3.3.10 Peak Suppression pool Temperature 160°F 3.3.11 Maximum Equipment Design Temperature Per UFSARSection 3.2.11 3.3.12 Maximum Containment Pressure - Long Term 10-11 psig @ 600 seconds ( >600 seconds) 8 psig second peak 3.3.13 Maximum Containment Pressure - Short Term 48 psig ( ~600 seconds) 3.3.14 Minimum Containment Pressure-.Long Term 2 - 3 psig 3.3.15.Minimum Containment Pressure -.Short Term

• Not addressed 3.3.16 Credited Containment Overpressuri.zation at Time of 2 psig in the first 600 seconds *and 0

' ',r Maximuin Suppression Pool Temperature psig after 600 seconds I 3.3.17 NPSH.M~giri-Long Term Approximately -1 foot ~. .. i,._. _; ~*~..... * ~- ~- 3.3.18 NPSH Margin - Short Term * -4 feet cavitation accepted 3.3.J 9 ECCS Inlet Strainer Head Loss 5;8 feet @ 10,000 gpm 3.3.20 Decay Heat Model May-Witt methodology 3.3.21 Condensation Stability Criteria.* 20 "F below saturation during SR V r discharge.* 3.3.22 Assumed Station Operator Response Time IO minutes*. .. :DESCRIPTION OF THE PROPOSED REOUIREMENTS .Section 4 provide~ a 4e~c~ptl~~ of th~ pr~p~sed changes ~dressed in this License Ariiendffient..:Tlie revised Te.chnicai *Specifications. and plant License Conditions*

• • • are 'also described in'Section 4 of this evaluation.* Section 4 also provides a

. description ofthe-prop0sed changes to the.key Co~tainment Heat Removal System configurations for the LPCI system~ CCSW system, the uitimate heat sink and the suppression pt)OL * * * * *

• 4.1 Descripiion of tlle Prqposed Revisions.to the Technical Specifications

.Ba5ed upon the reswtS ofComEd's revised ~atyses, changes are proposed to be .incorporated Into theteclµrical Spec.ifications and'Tedutlcal Specification Ba5es. __..Ades_cription of the proposed_changes are provided in Attachment Cto this ~..

• -report. ;Only.changes.to:.Technical Specification Sectioi:t 3/4. 7.K, "Suppression

~* : *.:".. -.* _JChaIDber/' and:Sectioil 3/4~8:~, Ultinlate Heat Sink; are necessitated by the -~,-. _:_:.:."~--~~; :*.. f.. ;** . "**.... ~ *. :-...,,..

ATI'ACHMENT A BACKGROUND AND SAFETY EVALUATION OF THE PROPOSED CHANGES ComEd proposes to revise License Conditions 2.C(6) and 3.0 of Facility Operating Licenses DPR-19 and DPR-25, respectively, as follows: Current License Conditions 2.C(6) and 3.0 specify the following: "By Amendment No. 1521147 [note: 152 is for Unit 2 and 147 is for Unit 3], the

• license is amended to allow the licensee to change the Updated Final Safety
• . *. Analysis Report to allow credit for two psig containment pressure to compensate for a slight increase in the amount of Net Positive Suction Head (NPSH) deficiency during the first 10 minutes following a design basis accident (DBA)."

.. *comEd proposes to delete License Conditions 2.C(6) and 3.0 of Facility

• Operating Licenses DPR-19 and DPR-25, respectively, in their entirety.

ComEd proposes to revise TS LCO 3.8.C.as follo~s: CurrentTS.LCO 3.8.C.2 requires-a maximum average ultimate heat sink water

• .temperature ofs 75°F. The proposed TS LC0-3.8.C.2 revises the limit of

. maximum average ultimate heat sink water temperature to ~ 95°F.

• :  : -r.,.

Co,mE., The Fe~meat re~ an e:Ktemal ¥ist:tal eKamiBatiea feile*.ving BftY . ~.. e*/eftt wkeFe JJ0teatially Bigk leadiags 0ealEI 000\\if JJFe;*iEles ass\\if8B0e that Be * -

• *. signifi0aat damage *wi85 en0eWlteFeEI. Parti0HlBF atteatiea fe0\\:1Sea ea -

Elis0eatimiities in the *1i0inity ef the f-elief ¥al'/e eiS0BBFge Stn0e these BFe eKJJe0teQ .. -,:.**. :t0 l.=Je th~ JJeiBtS effti~est stFess'.".

• ,r;i.,

. _ *: *- - -~- ~:-:*** {;-'... -,. ~-. ComEd proposes to replaee thesix and seve~th paragraphs to the Bases of _* _. ><<-:.-~.. " - : _ > _ * * *Technical Specification 3/4;7.K,.in their entirety, with the following: * -*

~:.--:~.... :... ~.\\**

.... ~ -. :*

. ~**.... * :..: .,_'7 -~**. -:-,~;:*:;:t:': *:.*:'.)-.... -, " ',:"A limitation of the suppre~~ion po91 average temperature is required to ensiire. *

\\~;,t,'i;i~fir:t~Rf;';.~,,,:::::r:o~r=:~= :=z::=:; :=~:~.. *...

-~-~~'.:;:~,,:~~i}i~-~}:;~":i* -- :-.. ~emperature~;ao.not~xceed maXllnum.ajlowable val\\l~s*during a postulated p_BA'.. : ~,* __ _.

A'ITACBMENT A BACKGROUND AND SAFETY EVALUATION OF THE PROPOSED CHANGES or any transient resulting in heatup of the suppression pool. The postlilated DBA against which the primary containment performance is evaluated is the entire spectrum of postulated pipe breaks within the primary containment. Input to the safet}' analyses iriclude initial suppression pool water volume and suppression . pool temperature. An initial pool temperatme of95 °Fis assumed for these

• analyses. Reactor shutdown at n 0 °F and vessel depre_ssuriz.ation at a pool

. temperature of 120 °Fare also ~sunied for these analyses. The suppression pool is also designed to.quench the energy from safety/relief vaive discharges.. Thus, the safety aruuyses related to the suppression pool must

.... consider acci4ent scenanos that involve safety/relief valve actuations. The* limit

• .* * **
• for the suppression pool average temperature is set low enough to preclude local
  • boiling due to.safety/relief valve discharge via the T-quencher devices. In accordance with.GE NED0-30832, local suppression poohemperature limits are.

not required because the emergency core cooling systein pump inlets are located . *below the elevation of the quenchers. ., -.... -~ . ".'. - ~ .. - -.. *The.a~aifable net J>ositive suction head is less_than that required by the emergency.

• ' *.. *.. - * * *core cooling.system pUmps, thus there may be dependency on containment

~--: overpre-SS1:1fedtµing tht:; accident injecti~n phaSe.'~ -:~ >'* -...,,.. *' ..- No other ch8nges. to theT~chiiical Specifications are necessitated by the system* des~gn' basi~ recollstitiltion efforts. ' ~- !,:*.::.

\\..

• -~--

f-. __., -~ __.. ;. \\ ....... '.. ~ i..

• j". ;._*
• .1-

A'ITACBMENT A BACKGROUND AND SAFETY EVALUATION OF THE PROPOSED CHANGES 4.2 Description of the Revised CHRS Operating Parameters 4.2.i Limiting Accident (DBA) - Same ascurrent licensing basis (See Sec. 3.3.1) 4.2.2 Differential Pressure. for LPCUCCSW is 20 psid ~ The proposed requirement for Af> does not change from current requirement:S. The Containment Cooling Service Water (CCSW) system water within the LPCI Heat Exchanger is required to be ata higher pressure than the Low Pressure Coolant Injection (LPCI) system Water within the heat exchanger. This assures that potentially radioactive water from the suppressfon pool would not be forced into the containment cooling service water as out-leakage and hence released to the environment... To ~sure that this requirement is *met, the pressure between the two flows.is measured at the containment cooling service water (CCSW) and

• ' suppression pool water outlets (LPCI) of the heat exchanger and maintained by

...... the operator at greater than 20 psid. This current requirement is specified in the

• . :*:*.:,.current plant safety analysis and controlled within the plant Inservice Testing.

__...., :* ~ ~.. *.. *,.. _*,. *-Program (IST) and remains unchanged. In support of this proposed license

• * * * *::*'-amendment request, the adequacy of20 psid, as measured; to assure no out-

.. / leakage; was quantitatively evaluated. It was found 20 psid will preclude out- ~:;.... * ;*.... '.-.*.;

* ~ ~ _.Jeakage.and can be maintained during design basis loss of coolant accidents as

• ., : : * :. <.
• well as during nonnal suppression pool coOling operation. *

..

• 4:2.3 * -CCSW system Flow-Mi~imum (5000 gpm) - In order to maintain the 20

...-. psid differential press,ure between the CCSW and LPCI flows during a design

• *. _:basis *accident (DBA), CCSW flow is *manually throttled. With a minimum flow
• ,.at _5000 gpm, heat ~fer is a~eqtiate under accident scenarios. *
• _; * *:. 0*:

>~;_,'"./* '. _4:2.4* __ ECCS pump flow requirements (CS 565014500 gpm) - The t~tal c~re spray. ..'. ',"*/ : ':.. >. *_'.* :

• flowrate assumed in the 10 CFR50.46 analysis is changed from 10552 gpm.
• .:;:. -~ -~~--.
• ~;* ":(5276 gpm per pump)to 11,300 gpm (5650 gpm per pump)°to restore marginS in

... -~-... ... ** '.Peak.CladTemperature (PCT).. -(Reference 28, 29) After the most liqtiting-peak ... *.. : -Clad temperature of 2030°F at approximately 165 seconds, a total ECCS flow of

• >*.approximately 9500 gpm is necessary to restore core height to 2/3 core. Then

......:_. *approximately 2000 gpm total flow is necessary to maintain the core coverage at ... *. *f *

_-: ;::._'::: *.**.> 2/Jcore height and remove decay heat (reference 30).

• '.:<:* * ** * < *:,**; : ~~cA':i.5. * 'ECCS pump flow requirements (LPCI 5000 gpm) - Same as current * :_ :.
• .*.. ::_ licensing basis (See Section3.3.5):

~ . '-~-. -.:/*_p-:~,~~~:i:_:.,.:T :;4.2.. 6:: 1ristr-ume~t un~~;tai~ii~si-1nstrument uncertainties m-e not accolinted for

• * * ;~: 'i*:-0._~:..,}';_;£;~2: ;i;':.~,:-~:.~f':<~.. )..11.-tlu~.Pr~pos~d-license amendment. Rather, they are being accounted for in fue *

~ -. ~.. ;_,,.. _*-~

• .~ ~**..

..i;, ~

~ :.- i ~ ~-. .- '~--. *y .\\ ~* :- . ATIACllMENT A BACKGROUND AND SAFETY EVALUATION OF THE PROPOSED CHANGES 4.2. 7 LPCI Heat Exchanger performance - The proposed heat transfer duty of the heat e:?{changer is reduced from the reconstituted duty discussed in Section 3.2.7. *Specifically, the limiting duty is 71 MBtu/hr with the LPCI and CCSW . flows described in Sections 4.2.3 and 4.2;5, respectively (see Reference 6 and Attachnient F). This duty is based on a CCSW inlet temperature of 95 °F and a suppression pool (LPCI inlet) temperature of 165 °F. The amount of heat transfer surface and the design tube and shell side fouling resistances used to determine

• the limiting duty as well as the 6% tube plugging limit are not changed from the current licensing basis. Actual heat exchanger heat transfer duty will differ from
• 71 Mbtu/hr as CCSW inlet temperature, suppression pool temperature and fouling resistance differ from the values described above.

4.2.8.Seniice water inlet temperature is less than or equal to 95°F-: Same a.S '.'*original licensing basis, with a Technical Specification change to TS 3.8.C°LCO, - revised from 75 °F to 9~ °F. *. - . : 4.2.9 Maximum Normal Suppression pool tempera.ture limit is less than 9r equal

• :to 9S°F-Bame as original licensing basis, with a Technical Specification change

. - to' Ts '.3.7.K LCO, revised from 75 °F to 95 °F. ~

. 42.10.PeakSuppres~ionpool Temperature: <_172.1°Ffor NPSHcalculations *

. *.. *. ~hen coupled.with minimum containment pressure - case 2al (Reference (4 and.

• . ***14)); <.j76 °F for other purposes such as EQ evaluations - case 5.a.l (Reference

- (6)); -. The proposed license amendment request proposes to permit a maximum*

• .. pool t~mperature ofl 76 °F after the.vapor suppression function has been*

accomplished (i.e.~ the. reactor is clepressurized). The purpose of the _increased _. :allowanc*e for maximum-suppression pool temperature is to re_concile. *

• ,. -*:*/ *iriconsistendes iii the Ba5es of the piant Technical Specifications, supporting

.:.. :.

• design bases, an~ technical information discovered during recollstitution of

... -. associated.plant -system design bases. -Key issues identified are the effects of *.. _; meeting the Af> requirement$ (see 'Section 4.~.3) and the reduced heat exchanger

• • _>>heat transfer capability determined during ComEd's reconstitution efforts. Other k~y issues related to revisions to the µiaximum suppression pool temperature are
• .
• summarized befow: *.*.

". -* :ihe effect -~i the evaluati~ns on the M> requirements are to reduce ccsw

• flo~,.recluce *suppn~ssion pool cooling and hence increase*suppression pool

~,.. " maXimum te_inperatures.post-'.accident.for DBA's. ~,.-.i ..... :'"~.-*; ~~ *. v):~!f:.:): ~~'.:-.:.,~.. :.'-;. -.

• ~:*:~-.:~_The" effe~~ on local suppression pool temperature were considered and it was

"*'.: *.. * *;:;_::: *;.. :_.. ;~,-_- ;

__ : ;= --, --~~::*_:found that "this local limit can be deleted. * (See the discussion on Condensation .. *:~.

~:.,_........ - ~... ". ATTACHMENT A .. '(. ~ ....-~

• .BACKGROuND AND SAFETY EVALUATION OF THE:*PROPOSED CHANGES

~ . ~.,..

• .. Sirriil&rly, the effects on other components and structures such as piping,

<.. *.,.\\:pipmg mounted comp~rients; and the torus were evaluated and found to be

• ~~: acceptable.(See Section 5.5.3)-. * <:"*

• ~*,_.: ~.-:*:-;:_: :*~.:.....*. : "

h*.. \\ ' :!t -. The effects of higher suppression pool temperatur~s on proces~.related"

./'.>.~*:.~,:. :,

"'... *(..... ~*vanables'such as:LPCI Heat Exchanger performance, Nef Pos_itive Suction Head

-* 's:.

1

• .;:~f:\\":*: :~(>:.;*,,to'.th~ emergency core coolmg pUmps and containment pressure were calculated

...:-/.; ::-; ~~{;,"( -,~:~~;. \\~.. ~~_:):~*.. <;n~ f~e ~y case basis,to-coiifirm' acceptable results:... f :$~i;~~~f +/-~~~~~~if!~~~~1Ef:1;v~~~r~~c:;~~EJ;~~:~;... -~*~{,~~~~f..~,;..~f;{;~~:.-< ;*.r~:-;\\;,0-:(..~NPSH available: condit~ons. Tht'. m~~ suppre~sion pq,ol water temper~ture. *. '.

• .-(;*;~-*\\t,*.1)i.::~:)';~~:**:*~.. ;.\\.':.~>was calcwated to-be 176 °F::This 'occurs"' in.case Sal (Reference' (6)),-at ii.. ~....
• ,.,::?-.:'.*'\\t~:-....,.... *_~:;.l'~~*.. ~;;..i.':'..;-.... :;.*~/11'-*:*.*1.*".'";1,.

.--~* .* :.-("", ~--

r'.

• ~.

~ *" '._::*,: 1.~"-~;~;7:-;.:;~*;>:.~t::*;:~-:~:.; *f./ 1: sripj:>res~~on* chamb~r air *space.pressure of 3 :5 'P.sig: *The.Wfiter vapo.i :p~essure of..:.... * -':~,~;,.-:.;;:.~.~,:'.:~;!:.::::-*:s:.. ;;;... (~-~~:r:t":.. 'T76.~E:waterjs 6.9 psia: The*vapor presslire at.172..J. '.~ is-6.3-psia.. The lower

• \\,_,_

< -i~: '.}~ )ik~~~*g~';;.::~:::.-:-.:~?:'.~~:::~~ori~~rit ~pre~sure' of 2-.9 *psig. vs*:3 ?5-psi{*m~re than compensates for-the*.:~" -.c*.. < -~-. :~;~~~~~.:~~_.:*;=:-~x;-X~~l:\\t~/~;{(.~if(f'.f~~c~: ~. yapo~. pres_~ure_ 6.? *P.si~*~c,t :6... 9. p~~a: ;~See Sectio~ *4*.~.14* for furtlte~... : ~*.*.. : * *

• • -~;:.

• • • --\\.

-~.~,. *.. --.. -:; **:~-~

".... ~.. -*

~--

'~-

0 ) 1.3

• ~-~....,... ;*:"

~.... -~*. : -. : ' ., __... **,:,* ':('~_.... __ ;.,_.:,.'-.",:~:<<-*.!:..., *. '...., J'he suppression poql temperature.ana_suppressmn chamber pressure versus. _ *. ~t~~~~}~~~i:~~;~~.* ~ :~i~~~:~~~~~~~:-_ -~*:/.:,~:,~~~?;~~{;~;::;~;~{~::~-;?ff)i;*:'~.4!2'.:fl;:iq~tpm~~t;'fiii~/{j;~{jd(!~: (iQfzftriits* :.~Tll~.e.ffects on the. enviro~eritaf : -. *.... ?":',"-".*:.,.--...t.,-*....,..,,l.!*-;::'r.-..:.:::.. ~t.',*-'L"_:'.t_:_*-.:..:.~-.**l.:;.;;?'v~}: ... ~*-... *...... -- ..... ~*.-.:~v'<:* ** >-\\:..*._~ ~ ** I, .:~:~'~,;!~:;r.!,~}~:-{.:.-f, ~{ ;-~);. -i~l~q~~nc,at~~~.~~.. eq~p~~p.(l~:~oemg. ccms1d~r~d., 'Ip.e~~ffects_;ar~ e~pected to be::.,

• - :'*~:,~ ::::.~::;:'~~::.'.".-:: :* *.;.. ~~~~:/.*(** ~:*.acceptabfo:_~{SetfSectfon:53:11.and Sectio~:S:5.2)... *,

.. -,- t. *.*. {~~~~~~~~~.* "*:-~~~*. '.,:::.'('.":",f :;* <":/: *.:;-.C :;.,: /seconds)inaXini\\ml'*pressufe "is:at the 600 second mark(i.e. 'just.prior.to :.:.\\*. *.. r~~ 1 ~tyf ~~ql~~1~~r~it~t1i~~~~{~r~~~~~~~~~*~~~ 1 ~~:'.;**::,**.*.*.,... . '.. :*::::::~i-£~;..;*,...;:>.-;,~*=*},,,:,,* 1; \\:~~-:tp4.2~13 ~;Maximziiri"Contiiinmeni:Pressufe.:.;,~Short Tenf(-The.maximum dry:Well -., : :::**. **-: f ~~:,i~~1ifl~~~~it~~IJ~~~~~~~~!~J~~0s~:~J:~~-.;~;,.~t,.:.:... *. ~~~ ~~:. ..~t~~~&ii!Y.~~(~\\lP~I~~-s~§~~~~ o~rj~r~~~~~"~~~(~I[~~~:is'-~~c_iµ~1~~~!? -~-~ ~tl'<?,~: *!?~~-"(~~)~:h:;*.. .-.:~~~~- ~f'

~1~);:Ji.i~-~X( 'od~~H!9vjdes~tp(m9-ael_,'ot:9,c>J:iJ?i.Wri~*-*t p~$~~;~-q !~mpeic!trir.~ pqst ~~*~:,"A 1

:;:\\ '.:*.:. :: )*_.**

ATIACHMENT A BACKGROUND AND SAFETY EVALUATION OF THE PROPOSED CHANGES DBA-LOCA. However, maximum peak short term pressure post-DBA LOCA is . deperident on vent clearing dynamics which occurs in the first 30 seconds post I DBA-LOCA. The SHEX code does not accurately model this phenomena and other codes must be used to calculate the short term peak containment pressure. . Therefore, the design basis short term peak containment pressure and temperature as described in UFSAR Section 6.2.1.3.2, and Figures 6.2-19 and 6.2-20 is not changed. Additionally, UFSAR Section 6.2.1.3.4 which describes the calculations used to calculate the MARK I hydrodynamic load conditions is not changed. _ 4.2. t'4 Minimum Containment Pressure - Long Term Various combinations of * . Core Spray, LPCI, and CCSW flows were-combined With varying assumptions regarding thermal mixing efficiency and heat sinks to establish the minimum suppression chamber air space pressure conditions post DBA-LOCA. See Sections 4.2.17 and 5.2.17. Because suppression chamber pressure and water . temperature are coupled, the most conservative concurrent condition for NPSH was conservatively utilized.. The most conservative condition for long term NPSH was 2.9 psig with l72J °F water temperature case 2al in Reference ( 4)..

• *This combination is the bounding condition with respect to NPSH available for
• .Jong term past accident respon5e. *The-suppression chamber pressure v~rsus time is provided in*tabular form in ~efererice 14 for case 2al.

. The minimWn suppression chamber irirspace pressure foll~wing* initiation of containment spray was calculated to be 1.7 psig. However, this occurs in case*3

• inReference(4) at approximately.152 °F ~uppression pool temperature. The vapor pressme of152 °F water is 3.91 psia. The vapor pressure of 172.1 °F water

. jg 6:3 psia. The lower v~por pressure.at 152 °F more than compensates for lower suppression ~~amber air space pressure.: Suppression Pool Condition* *. ' Net A vail~ble Pressure for NPSH ' 1.7 psig@ 152 "F 12.S psia

• 2.9 psig @ 172.1 -F
• 11.3 psia 4.2.15. Minimum Containment Pressure-Short Term...

Various combinations of Core Spray, LPCI, and CCSW flows were combined with varymg assumptions regarding thermal mixing efficiency and heat sinks to esta~lish the minimum suppression air space chamber pressure conditions post DBA-LOCA. See.Sections 4.2.18 and 5.2.18. The minimum short term suppression chamber pressure and maximum . suppressfon pool water temperiiture occurs at the point of initiation of . containment c~oling and entrance into long-term cooiing~ "The minimum .. ; -.. suppression: chamber.pressure is-'2.9_psig at 533 seconds.. This value, together

~

. :.. * *: ~- =~-~ *J 4~~~--~~~-~~I>~~~s~i~~-P,~ol~~~perature: is_~~~.~ the NPSH calcwation ~or_-.. ~ -~-~.

~,.. AITACBMENT A BACKGROUND AND SAFETY EVALUATION OF THE PROPOSED CHANGES

• minimum short term NPSH, as calculated in case 6a2 of Reference (19). Case 6a2 assumes that 4 LPCI and 2 Core Spray pumps are operating and that the thermal mixing efficiency is 60%. This corresponds to a single failure of the LPCI loop select logic resulting in LPCI flow escaping through the broken loop without entering the vessel (See section 4.2.18). Case 2al with 100% thermal mixing
• provides minimum results for NPSH for a single failure of a diesel generator. The

. suppression chamber pressure versus time is provided in tabular form in Reference 14 for case 6a2 and 2al, 20% mixing. Reference 22 contains case 2al, 100% mixing. 4.2.16 Credited Containment Overpressure - See Sections 4.2.14 and 4.2.15.. The. minimum calculated containment pressure and corresponding containment pressure necessary to meet Net Positive 'Suction Head Required* (NPSHR) for. LPCland Core Spray are shown on Figure 4.2.16. As discussed in Sections 4.2.10, 4.2.14 and 4.2.15, these curves*incorporate the minimum coupled points for Net Positive Suction Head Available (NPSHA). The containment pressure. curve is ~combination of case 6a2 ( 4'LPCl/2 Core Spray

Pump Combination) of Reference (19) with 60% thermal mixing for the first 600

'*.. seconds and case 2al (1 LPCI/1 Core Spray/2 CCSW Pilmp Combination) with.

• 2Q% thermal mixing after 600 seconds until termination of the scenario. *
• ... 4.2.17. NPSH Marg_in - Long Term (600 seconds until a_ccident termination) -

The containment analysis review~d multiple combinations of core spray, low pressure coolant injection and containment cooling*service water pumps. These analyses are presented in the calculation results (References 4 and 6). . *The NPSH Margin is-affected by two variable pa.nm.ieters, containment pressure

• and suppression pool temperature, which are' components of the containment...

. analysis. The containment pressure following a Design Basis LOCA, rapidly rises. This pressure then remains relatively constant and is only affected by the presence of heat sinks ( drywell shell, vent system and torus shell). Post LOCA, the operator takes action to spray the drywell and initiate containment cooling which is credited at' 10 miii.utes after the accident. The suppression pool temperature at initiation of the accident is at 95 °F, rapidly. . increases to approximately. ISO~ and peaks at 176 °F'. Suppression pool* temperature peaks at about 5 hours after the accident.

• At this time, containmerit

~ . cooling is able to remove more heat than is.being gene~ted. Operator action is ":* -*... * *.... credited at 10 minutes to place the Containment Cooling Service Water pumps

• ~ : and LPCI h~at exchangers (in conjunction with the LPClpuinps) in operation to

':.. /. _-.-.' : :.: -~. -~-*:fe~~ve.heat fro~. c~n~ent~.

J~j~~!1".;"* 0 ~~E~~~)[~-2-1T ;,-'.":_:. :.-.*.. ~. :. ~

t*** '. I* . II . '\\

• .\\

. ~ * * ! * . }. Minimum Required Contelriment Prelaure-ror NPBH Conalderatlona Only

• (Arter 10 mlnutu: ca_ g nomln81 flow; LPCI throttled to IOOO gpmiHx)

i'**... ***,

2 t' 0 5 _.i....:::......:....:.._..:,_.....,.--'.:..:....__. ___,;_.....;;..+-.:-...;:*.:.:.***~\\-'--4--~l--_;_,;_.J.-_;___:_.J.------'"---=-==P=o=o=l=P=r=*=*:;11=u=r*=A=v~*=ll=a=b=l*======----I -Pool Pressure Required. Cora Spray _._Pool Pressure Required

• LPCI

.10 -I----'---'---'----'---'--'-----'-_--'--+\\_. ---+---'---+---*

. ------------+-----'------'--------t "* \\ ~-

• j j"*,

-~. 0 -5 to * ---~~~--*-~-~~.. ~,; too Paak PCT (°<200 iac) tOOO Time (Hcl to minutes Raflood (<300 HC) tOOOO DRESDEN STATION UNITS 2 & 3 tooooo MINIMuM CONTAINMENT PRESSURE AVAILABLE AND CONTAINMENT PRESSURE REQUIRED FOR PUMP NPSH FIGURE 4.2.16 (Figure 6.3*80 of Proposed UFSAR Change)

~.. ~ -.*.. .,1 ( . **(;.- _.,._. ,J.:. . ~A:TTACHMENTA - ". ' BACKGROUND AND SAFETY EVALUATION OF THE PROPOSED CHANGES

• . ' ' ~ -

.. ~"'... .* r.

• ~:. -.

~**::*: '.:L6hg t~~is ~biisi~,er~~ ilie ~im~ period from *10 inin~t~s. post ~~cide.nt until. .. _ '. *:.. *.-*.'.: ~.terrilination of the acddent. *operator action to spray the.containment initially ~; ".*- ::.:*:<,*,._-_> ~-:~e.sUI~ ~-con~~~~t pf~ssui~: b~ing reduce.a to a.minim~: *Stibsequen.tly,_.

• ....:, ;',,:.. '. _;:. >*.;;,;,:.'.-.. coiltiiinment pres.sure s,lowly incr~ases until the containineilt heat being earned.:

.... f;:;~%fo'./t,~~!~-~~~~ti;t:.:i;tdL!f J~e;e:~~=~::.~~~:~;;::!~~~lin~:~:::*. -~-_.,*~-.,:*;:~i:<<~~<<./.'!~{}peri()djs approxiinately,:'5:.hours*.~;*Thtciugh review* of all puinp combiilations, ' ~:~~- , ~ ."> ;* _:- :_.;-:;;?""':*.'. ;,;:~)~/._:.,_z;4/~~:*:-:coi:tjbinatio~;-.. the?LPCl:purnps have :a margi~ <<:>f -4 :8 to..3. 8 feet and the Core r--*",.

• ~*

~. ~ -:"'!........ :.....,i.:..-** :..,"I.. "~-

',\\*~*-.!**

~. ~ ~- _..,.*-:c_~r,~-.-'F5'tS~'£,i.:;~;;~;5:i_;;)Sp~y~puµips*hav~"a.miirg~:_of-1.0*to 8.5 feeCCalculation DRE-97-0010, :

*/> _;::¢.1 >+;;/;~;r~<1t1:~<';:~f~;(Reference.'l ). ~valliates th~ *41i. and 3/i PUil1P ca5es~Jo :ensure adequate *flow is.

~....... -** **;,... *~:-;:.*_....:*.;,;;.. -.;-*":~:,... :.::.~~-~ *,.,:; ~*l *:- .; *.-., *,t-".'_*.

• • • .... _J

,( ~ .. ::.:~:~.. :1:;~*;~:;:*u.~~~~~t~:ihl(~*:;(ayaila]ileJotcore aricl.containment.cooling from the-.Core Spray.. and LPCI pumps. .... /.-t*--,~,:**~~;+**'t.:>'... -*.,....:"r;:-~i--..,1;*.x '.' ;?.'~.-1:.; _-:-*. ~ :*?,*. :. "; -~ -... :~<~"~i~~:~;.~~~~;~~~~.~~;~~~~ '.~~~}.e_~~~~ -~ ~~e::~~~J~ble: ~.~I:I:lo~.:~e-~~.C~*1p_um~s_-_1s._a~~oun~~~ :f ~r 1_n. th~,.-:.- .. _ ~- -:. *.-.-:~:;,,:~.~~ -~:r,... "~:~:* *-.-_~(:.~~'),,ca:I~Wati~.n-.by~takll)g -operiit9r.action to Jhrott~~ the pumps. Operato_rs are tramed" * * * * "~ ~~: r~

• *,". _*_<J*,'*~f;~.;-~,~?.;,;:~_. -;;::~~~::J~ffl.~,l:I~~~g11_1SJor:cJ~di~l;Jle:pUil1P.*co~bmations* f.µ'~.-summanzed.belo\\V from,".....':. *. * -

ATIACBMENT A BACKGROUND AND SAFETY EV ALUA'rION OF THE-PROPOSED CHANGES LPCl/CS Pumps @ Minimum LPCI Margin Minimum CS Margin I)

2)

3)

4)

Throttled LPCI Flows (1) 4/2 (2) 3/2 (3) 2/2 (2) . 112 (4) Feet 10.6 2.0 12.4 3.8 . All core spray flow rates are at 4500 gpm per pump LPCI flow rates at 2500 gpm per pump Two LPCI punips at 2500 gpm and one pump at 5000 gpm LPCI flow.rate of 5000 gpm per pump 6.6 6.6 8.6 8.5 Feet -.. ~.. *. *:*.: -~ -::..._ ;,:** _.. '".. . As shown above, for ECCS pump combinations, the LPCI and Core Spray pumps * ..,.. can* be _throttled to ensure pump protection and adequate containment cooling.

• Y *.*,. *The 'long term minimuin flow requirement for total LPCI.flow is 5000 gpm.

.. (. ~ _ ': (:': :: : :.::o * "::_,::: :In.sWlunary, selecting,inputs to minimize NPSH margin, it was detenriined that ..*.... * >;:_;.~\\_(-

~_* -C:*<:-~**idequate NPSH _eXists-to meet Core Spray pump requirements and performance.

':-: :y> '. *<;' :* __ : *. *. f~r ~l p~p combina!ions. However; the potential e~sts for the LPCI pilmps t~ -,_ '. -ca".1tate at rated flow m the 4/2 and 3/2 pump. scenanos: For these cases, throttlmg . * *~ :- -. '. '. -~ **-below rated flows of the LPCI pumps is required.to ensure NPSH requirements

• - * *.- are met. Jn_ every case~ minimum total flows of 9000 gpm Core Spray and 5000
• gpm LPCI are maintained. Specific cases involving throttled LPCI pumps were

-. *.evaluated to establish the ability of the operator to throttle the pumps to an

acceptable condition. Under post-LOCA pump combinations, positive NPSH

<:.c:;;*_ :- ::* _- :.: ~ *.. margin along with.the requisite.flowcould be obtained by throttling the' available * ~- -.::_: -t::-.:> ~,~ ~~-, : ~-_. -~pc1_ p~ps~; _-_ ; _ -,* *.** - -_* ~

• 4.'2.1.8 NPSH.Margin :...Short Term Short Term i~ considered the time period

;._ > '-* ":*from initiation of the Design Ba8is.LOCA untiJ-10 minutes post accident when

.* operator action is credited. In this time period (depending upon th~ accident

• • ,**_,*,-,:~>"':-~-. >> *

.. scenario),* the containment pressure peaks and pressure starts to decrease. The -.>: _--.... _:~- **_::: most.lllriiting single*failure scenarios encompassing the various LPCI/CS pump <*::?-.:,\\'.--: :-_-.: __ ~----. conibinati.on for ECCS r~sponse to PCT and 2/3 core refloodcapability_were* **

• * '~'..,c* :..~:\\~: *: evaluated. ::Th~ NPSHmargin is calculated in reference2.

',: :,.:..:.. t-~~~- :,~-=*~... - '. _.,:). ~--.. - :* *---:-.'*,?'-_:+£j,~~~:;<-:i::.. _ _.-.-The ~ost"illniting failures relating.to Peak Clad Temperature (PCn were* -~::.~e~J~~z:1w:¥:~*Lkt~,~~=: t, *.. i-: : - -. .. *{*,:;fi#}T~ 2 '!), Sf:-:IJ'c:J= ~1,llll:_of 8 LPClll\\i~!!D Ylllve J

AITACHMENT A BACKGROUND AND SAFETYEV ALUATION OF THE PROPOSED CHANGES _. This case results in two (2) Core Spray pumps injecting at maximum flow with four (4) LPCI pumps running op. minimum flow on recirculation to the suppression pool.

• 2) SF-DG: Loss ofa Diesel Generator This case results in two (2) LPCI pumps and one (1) Core Spray pump injecting at maximum flow.

The most limitin~ single failure with regards to LPCI/CS pump NPSH, however, is failure of the LPCI Loop Select Logic (LPCl-LSL). This scenario involves the

• LPCI pumps injecting into a broken reactor recirculation loop and is discussed in detail in GE SIL 151. From a PCT perspective, this case is identical to the SF-

.LPCI case since*the net result of each scenario is two Core Spray pumps injecting into the coi:e'~th no contribution from the LPCI pumps. SF-LSL is the NPSH .* :.... ~. ' :limiting scenario due to the LPCl/CS pumps operating at ~e highest ~chievable

• *flow rates, resulting in.the qiaximum pump suction losses and NPSH

~' -.. - * :.:**: requirements. Both the.SF-LSL and SF-DG.single failure cases were evaluated.. * . -. :The SF.:.LPCI case-is bounded by the SF-LSL case arid is not included. ~** -1. LJ>CIICS pump.flow reqtiirements are a5 follows:. f.or.the-SF-LSL *and SF~LPCI cases~ a two-pump C~re Spray. flow of~ ll,300 --. :.* _*. *~" : ..... gpffi up fo the'200 second inark reswts in a PCT *of.::5 2030°F.. - For the SF~DG c~e, a tWo~pump LPCI flow of at least 9000 gpm and a single Core-Spray pump flow of at lea.st-4500 gpril are required for PCT considerations. _ _ " >:: * * *... :~. : ; : :Qruy :a co~t-total p~p flow of 9500:gpm is reqclred to achieve 2/3 core {- ;~ * :*:_<* reflood in less than five minutes. After core reflood.a nommat flow of 2000 gpm . -. is necessar}' to remove decay heat ~d mairitain core* height. Therefore With the higheSt pmnp fl~w rates~ md most limiting single failures, the ECCS will still. . perform* its 'function.in the short term with no credit for operator action. (See

• *secti~n 6.0) *
• ~:. JTh~:mminnici suppre~sion pool pressure reqUired to meet LPCl/CS pillnp NPSH

-. -. *~requirements was detenn1ned for both the SF-LSLand *SF-bG single failure

• -**'*cases.* The minizD.uinpool pressure required was compared to the minimum pool*

_:~.-_., *-_pressure availabie post~LOCA for both cases: Case 6a2 with 60% mixing is used -~ }j_ :: ' :'.~~_-:._ ~-::*~-,: '~:: __ ;': *<for SF,:LSL ccint&runent conditions. *case 2al with 100% thermal mixing is used -~-;. -* :, ~-:~~/~. * ->:-:, -~.-_ : ::::< _'.;f~r the.SF-DG.contaillment conditions. If the pLressure available is gteaterthan. -.{~~~;:/~)2:~~;~'.,;::~:;J~=;=~* ~:.-~;'.~;~:~,::-~.-~~pr~sslJ!e.reqwred, th~n ~equate __ NPSH existS. If the.avrulable pressure is less . -'.:, ;'."-:'-'7::~'*:~ ::';.!i:-~*::;;1/ :*,~:~' ;~. .-: ~.ithail"the 'pressilre required then the potential exists for the pumps to.cavitate r:~. ,~:. :':*; -*.-. .... *~... .i

• . \\.

... ~*. :: :. :... :

• AITACBMENI A BACKGROUND AND.SAFETY EVALUATION OF THE PROPOSED CHANGES For the SF-LSL case, no cavitation is expected to occur for the first 290 seconds post-LOCA. During this time, the CS pumps will deliver maximum flow of 5800 gpm. Since PCT occurs at less than 200 seconds, the CS pumps will deliver
• adequate flow to ensure no impact on PCT. After 290 seconds, the LPCI and CS
• pumps may cavitate, resulting in reduced flows. The CS pump NPSH deficit reaches a worst case 10.0 feet at 533 seconds; Under this scenario for NPSH, Core Spray pump flow will reduce from 5800 gpm at 290 seconds to about5100.

gpm at 533 seconds post~LOCA. For the SF-DO case, adequate s1.,1ppression pool pressure is available *to satisfy LPCl/CS pump NPSH requirements for the-entire 10 minute period. That is,* no. * .LPCI/CS pump cavitation will occur, nor will any flow reduction take place from. -'. 5800 gpm for Core Spray and 11,600 gpm for LPCI (5800 gpm per pump). 4.2.19 ECCS Inlet Strainer Head Loss (5.8/eet)- Same as_current licensing basis . describe~ in References (18), (21 ), (22) and (23). Note* that new strainers:-will be installed to mitigate the concerns raised in*IEB 96-03..These new strainers will

• .. *have ~ smaller clean pressure drop than the cl.Jrrent strainers.
• ... -4.2.20 Decay Heat Model--ANS 5.1-1979-Branch Technical Position ASB 9-2, *.
• ~Residual Decay Energy for Light-Water Reactors for Long-Term Cooling,"

specifies the assumptions*and formulations that may be used to calculate the .resid~ decay energy release rate for light-water-cooled reactors for long-term cooling of the reactor facility. As noted in ASB*9-2, the decay heat generation due to the.heavy elements U-239 and Np-239 may be calculated according to the expressions discussed in ANSSJ-1979; "Decay.Energy Release Rates Following Shutdown of Uranium-Fueled Thermal*R.eactors. The model represented by ANS 5.1-1979 provides a conservative representation of the fuel decay heat following accident conditions. ~s.decay heat model was chosen since it is the current model approved by the American National Standards lnstitµte and both the 'industry and the NRC staff have acknowledged that the ANS 5.1-1979 standard is . a more realistic model than previoUs models.. Although the ANS 5.1-1979 decay heat model is more realistic than that used for the origin.3.l Dresden FSAR . analysis, cons~rvative results fo.r the Dresden containment beatup analysis.were assured by u5e of conservatism in the input and analysis assumptions. This standard includes significant techni,cal,advantages over the older standards in that ...it deals m*gre~t detail With the.physics involved and has a significant data base.

• .. The decay heat clirves d~~eioped by GE, which are based on the ANS 5~1-1979

.,* ~-,,..':;.'.**... :-.;. *.:.. *,.*.. *_decay hea~ model, iilclude_fission product decayheat.and other major_ contributors <-*~-:;,'..:~ *... **-~._. * :: *, -'.to post-LOCA heat* generation. The other contributors mclude decay of actinides, .-:.~~-~~*J>;>{:,;.:~-~;-*:*:<* : ~e~_~y~.o~ a~~::~:~ p~od~c~'_ ~d *~ss_~~:.he~t _due.to ~-elayed neutr~~* ~e model

~t-*

~.~*;:;~:~~*-*. ~*. ~~~~.-... ..~.* -~~ '.. ~*

ATTACHMENT A BACKGRO~ AND SAFETY EVALUATION OF THE PROPOSED CHANGES is not sensitive to fuel vendor, and therefore is applicable to plants with Siemens fuel like Dresden. Based on the above inform~tion, ComEd has determined that the ANS 5.1-1979 decay heat model provides a more accurate representation of the decay heat

• during a LOCA than previous models and thus was used for this analysis.

4.2.21 Condensation stability-Dresden Station is equipped with safety/ relief valves (SRVs) to protect the reactor from overpressuriz.ation during operating

• transients. When the SRVs open;* steam released from the reactor vessel is routed through SRV discharge lines to the suppression pool where it is condensed.

Extended steam blowdown into the suppression pool, however, can create .. temperature conditions near the discharge location that can lead to instability of the condensation process. These instabilities can, in turn, lead to severe vibratory loading on containment structures. This effect is termed condensation oscillation. * . This is mitigated at Dresden Station by the usage of quenchers at the end of the

• SRVdischarge lines, as well as restrictions on the allowable bulk suppression.

pool water.temperature, in order to *en8ure that the local pool temperature stays within acceptable ranges. Techriical Specification SectionJ/4.7:K provides . Limiting Conditions for operation and Action requirements, regarding the suppression ~hamber pool temperature.": The NRC:~ appro~ed (SER dated.A~gliSt*29~ 1994 via letter G. Holahan to R. Pinelli) the BWR O\\vners' Group (BWROG) GE report, NED0-30832, dated .March.21,.:1995, entitled, "Elimination of Limit on BWR Suppression Pool

• • Temperatiire, Reference 8. NED0-30832 presented a discussion oftest data and analysis.that suppqits deletion of the requirement to maintain the local.

• .suppression pool temperature.20 °F below the saturation temperature of the poql

• during.SRV discharg_e;,.*. ** *.: * * '*

4.2.22 Oper~tor. r~sponse is ~redi,ed at 10 mi~utesfollowing LOCA - Same as Current Licensmg *Basis (See Section 3.3.22). Table 4.1 provides a table of the

aforeme~~oned parameters.* *

• ... -~

-~. ;...

• • .... '.~

_; r. ?' ~t.. ' ** '; * ~,.._. ._-~- ~-- _+,-.. -~--.... - '.. *.. : *.. ;.... :t".,- -~: ~- *: ':"'

~. f ATIACUMENT A BACKGROUND AND SAFETY EVALUATION OF THE PROPOSED CHANGES Table 4.1: DESCRIPTION OF PROPOSED OPERA TING PARAMETERS PARAMETER DESCRIPTION 4.2.1 Assumed Limiting Accident 4.2.2 LPCl/CCSW ti.P 4.2.3 CCSW Subsystem Flow - Nominal 4.2.4 ECCS Flow - Core Spray (CS) - Nominal 4.2.5.ECCS Flow - LPCI - Nominal 4.2.6 ECCS (LPCl/CS) Flow Instrumentation Uncertainties 4.2.'7 LPCI Heat Exchanger Perfonnance 4.2.8 Maximum Service Water Inlet Temperature ~4.2.9 Maximum NonnarSuppressi~Jl pool Temperature 4:2.10 Peak-Suppression pool Temperature. 4.2.11 Maximum Equipment_Design Temperature. 4.2.12Max,imum Containment Pressure-Long Tenn (>.600 seconds) 4.2.13 Maximum Containment Pressure-_ Short Tenn~ 600 seconds 4:2.14 Minimum Containment Pr~ssure - Long Term 4.2.15 Minimum Containment Pressure-Short Term 4.2.16 Credited Containment Overpressuri7.ation (Long term at time of peak Suppression Pool temperafure) 4.2.17 NPSH Margin-Long Tenn. 4.2.18 NPSH Margin - Short Term .. 4.2.l 9 ECCS Inlet Strainer Head Loss . 4.2.20 Decay Heat Model. 4.2.21 Condensation Stability Criteria

.4.2.22 Assumed Station Operator Response Time PARAMETER Large Break LOCA 20 psid 5000 gpm for heat removal 5650 gpm for first 200 seconds 4500 gpm after 200 seconds 5000 gpm Instrument Setpoint Control Program 71 x 10° Btu/hr @ 5000 gpm LPCI flow and 5000 gpm CCSW flow 95 "F 95-f.

172. l "F for NPSH when coupled with minimum containment pressure

• 176 °F for o!Qer purposes See Section 5.3. 11 16.5 psig at 600 seconds approximately 8 psig 'secondary peak 48 psig, current licensing basis retained 2.9 psig for NPSH Considerations; 1.7 psig when coupled with max temperature

.2.9 psig See figure 4.2.16 See Figure 4.2.16. See Figure 4.2.16. -5.8 foot (New strainers will be lower) ANS 5.l'."1979 methodology None - NED0-30832 IO minutes. ,.. :. *... ~ r, * *. ** ** **** ~ -.

. ATTACHMENT A I .,_ : BACKGROUND AND SAFETY EV ALUATIQN OF THE PROPOSED.CHANGES

• ' *.,*. -:=5.'""'-0--=B=A=S=I=-S-=O=F--=T=-=H=E=-=-PR=O-=-P-=O-=S=E=D-=RE.=.>Q"-'U=-=I=RE=* =M=E=N-'-'T=-=S *
• ... '/'. :<<" *. *.
• _Section 5 provides. the basis for acceptability of the*.proposed changes

  *.. :_:.,., :.::~ : *. *~*-

"t --:. i&ddressed in this *License Amendment request. Seetion:.5 also provides-Our ."-..--.~*.*-:,> .. ev~uation supporting the.acceptability of the prop~sed changes to the.l<.ey. .. '.. *;~: ~:~.;~;~~~:-~i.//.:*.. ':/ :":://*~~ *::r:copt~e~f I:Ie~t:Re.moyal :S.ystem par~ete.rs fi~r *th~* Low Pressllr.e Coola11t' ** '..

• ' -~ -_'}::'.':i(~;~'.J/'.:" '::".i"J: :"* :; Jiijection (LPCI) system~ _Containment C.ooling Service- ~ater* (CCSW) system_,:--.* **....

}'.'J~~~~~~:;;},t;)!t~~i;ate~t*illic~~thOS~pp~\\io~.pooL > **,., r., ; ~.... ~.,~~"--i.X;:<£~'~:,-.:;,~ : ;;::::_-;;_*. _

_:;.~5.~:l._~ :Discussion.of Revised Technical Specifications /License Conditions">...

'-* *~ ::"..;>.. ...-~~~::~/{r~;!~~~~i:<~~~~.. ~~;>;~~-~~~'.~.~(~:}~~.::~~:-~:*::;~,*;* >~:--::'.-.~~.:::.~.. *... >~;~_,~.~ : ...-.:.... :/*\\-':.. ":*~ :-':'..: _:.. ~ -:. ~:... *.... : .... :--. **:*:~...... *, :;.:.

• <<<*~,

-,>~":.i'.f:"~,*~:.,~<'7?,;~~'.'_'.:i'.f!'-:;::.:.. "'As previou~!y.. discussed,-ba8ed upon the.tesults.ofComEd~s revised analyses,:...,.. ~...'-.::',, ---:1....,i._.,...... _ .. -:..*.:-.!*~_.;:._-_:\\':t<;-'°'.;.._;,.,*.,.,::.:**.,.-,

• C*

~~~r,:~*lt:~-rf£~2,~-',;ft~~~{?~'- :~ ~;:'~~~*,.:,: ~J;ianges:are _pr,opcjsed_ to be_:mco,rporated mtctthe T~~~ca1_;Spec1ficattons and_*.*.. - :,. *: _. *

D~(~~~~~:~~2f:,:*Q;~f;~{-~if e~.hiiita1 Specification Bases;: Orily changes to*_Techirical Specification Sectio~* _:_ *,.. ~'.

.:-~.:~'fq:. -'?=;:~ ~~*:.:.24~2* .::**-~*.:::.:.'"! ~:,_ ~ ~ I~... v.~ ~ S. --~-...., 'i. ~

• h r

-..,..,~~~?~:'i:;!~~t~~-~< 0'"-':*'i"~*.-,;~_:JJ~. 4.7;.~~,_ uppr~ss~on.C ~ber; *,and.Section 3/~.8.C; Ultimate Heat S1~,. *are;~>.-...... :..,:-.:--.. -*~.;..-h~......,..,... h,.\\-~ ** ~,t--*-.:.::]t.**.. :.;.--~.. -* ~ --. .~- --~ t l .;;~' :~~i#-'!:~-....... *, ',.:,,~~.:,t./U~~:,ii~9essitated,by the -~e_consti~tion. efforts:.;_Th~* folfo~g summarizes the purpose.*"*.'.- : _*. ;'."--- '* '~,~},~:;~. ~.,:,;~~~!1~t~~;,~;-&rt0~~~~;~;~i~'~,~~~f;:~;?~'t$},*: :;iA:,ts;c;~ ~<:L. ., * *.* **. \\t,:".:,~-.~.;:~::;~{~=-i>,:~:,;~ 1'.'*~+.::,;*,,1.:.* ~CoiriE{:l propos*es*1o;deleteJ.:iCense Conditions'2.C(6)*and.3:'0.of:facility... *.: "*.; ~*.,**.-.-:.=.-:.. ~-c '" -~~~¥1:'.Jl~f~:f ;: -~~B~1~~:~9P'~r~~ip~~IifS,~~.~j~p~ll4~. ¥1~.P~~~~?.. ~*~~~~-ect~v;~~Y ~:~:-~ei.~~1~~~--:* :'Y~~fr.:.: '., "\\~~.~: :~:.;:. ".. * /.\\)~~J.~,,.,*;.. ::'~~-$f~d1{-c~~Br?"'~~.:~f~~~p~~~~sed}1~~!1~~ ~ell:~en~.r~q~~~!;:~~-~~ F~c~~e _c<?~~1~?~ -~... _*: ;_: ~. ~;::* , ;t S~~.,~~:'.~<<:'.'.;~:;;;::*:;_~~; ar.e_.reoundaµt:to: the_plant;;!:echnical _Specifications and UFSAR;~which.prqvtde.- ",y*",_" ; - ~f."t_ ,.. t;,,.... "'-i:.._*:"'.:f' -. ** ~*-~*~".-, .**.J ,J;:-*..,_*--*! *. 1... *£:i*"*(',__, '.'1

• ~

r.o ';_.;A.,._.; ** *". *1:!"00

• 1*
• .L

'.*;~" *:,*,~*.~:f:Jc*:-L;::,~~it-~;:{ti'.-': *;,;.~-:.~- stiffici~nt'controls* fot:.tlie. plant:licen8ing ba5is:~-::A:s'-srich;>tlie *provisions of-10":.... ';:*-:-.,,:.,:.. *.. * " -* *.... -:;.:~ c;_-~;~~~~!.. ~;;.~;~23~;*!i£-'~~~;~<i(¥ "$p;.s~:~pr~'?<le~~~;cie~!~f~.Ci_uire~~~-~,X~ --~~~~:,_an~:-,~~b~~Ci~e?~ -~11.in~ef ic>> ~ _:.. ; __ :*,::::" ~, :-. ":<Y ~:C~}::.".:.:';t~:~*:s,:::':.~*~,:;~,.}_~*;*:~e plan~ithaqp.volve"anUnrev1e~ed;~afety Questtop. receive NRG staffrey!eW.'::>""':.-~-.._... "* - f ~iili~~~it~St~*~~~WJ~t~~~!~;~~~~i~~j~~~;[~"c',~,/,....

{~~"~::~::*;~:~:~~~~:;~r~~~~~~<!;t:do~s_:~of~~ftplari(,~pe_~ti<?_n.~!.. ant:plan~:P¥affi~fors -~sociate.d -With.the.CHRS_. :*. *:.'-.:. :~::.. :. *

~~

1~t~~WJ!~&~~\\~~~;~~~~~~~~t~~1f ~1i*t:.f5§~5ji£~~ff~f~fR~f,:d*~;;J._;.~ 1 t****,* __ *

.'":-.~.*..:*~-~~*"::"'"t(:0_,_.*~7'.*,<'.::;:~~~*.:> :QoiriEd prop9ses to-r~vtse.~TS~LC0,:*3.8*:C as:follows:.-:-- * *_.<*: <*::-~:.~ '.,-:* **

• *:. -:--~*".. * -~

'~j~::~~~~{:~.ic~~t~~~;;~~~;:.>~::~~+~::,:~1r* ;.~~~~:'.~:: i~:~:}~;@1~ ~~%~1:¥:\\; \\~~~~~ \\~~~:~~~::t:-~-~-~~~:}~<t~~.~ ~.~,~~:: ** :;~<,~~.., :,

~-: ; ~....... -.. * : *: : '..:,

1;.;*~_,,.;,..~,~ir'~:~;_:-:;*z.;:~,,?~~:.::: :* i<:.::,. !Gµtrent"fS ;LCO -~.8~C,2 *regwres*a *maxmi\\Jm average ultimate"heak sink water. * :.--

{~::~{t.~~;.r~~)Jt;;~;_:.:~~{/::~ti~fuR~~tltr.~)>t~-~~~~~tii~jfoJ;6s~~r.js_1;_¢9 :1:'8~~:rre~i.s~s\\~e.#niit' of\\' _

~, * ** -* * :.:.. ~~~~~~~- : ~i/ :_';'~~ .~iZ~r,:2~TI1~ie\\iJ~&1s~rR~_<;f~ ~s!p;2;Qc~:9:5.'W ~1Jr6Vi9~l~' Hriiiiatfon-on ilie ¥lti~~te *heat;:~*~>> :-: :. ~- : : -~~.~~~~~~~~~~~I~i~t~~~~ffii@jz~t~s~#f~~}~~~,1.~~-:~'aiji~-~;f!je.c~j)a~i1~!?'io*~§sip.a!~~;i:**;~;:.::~~*:~::,*((.~: '~*-.;"

"'.~-res1duaHheaLaftef(reacfot;shutdown'aftil-.'des1~. ba.S1s

acc1denC' The mcrease:of.. ::-:*,\\ "'" :-::.>: "> ~., -- ".

~

• • -.S"'

I<. ATTACHMENT A.

• ~ *'

'"t..:!',* *** : ~.. J ... '. BACKGROUND AND'SAFETYEV ALUATION OF THE PROPOSED CHANGES '. .*a;siuned for the revised. safety analy,ses requirements are "maintained, the proposed > *change is ~cceptablefor.usageat'Dresden.'Station.- '<-~:-.. ~~----*:{*: :,.~J-.>,*,." "--.~ :.*-*. -_*.-_.*-:.-..:;,, c~~d prop~ses'to revi~e*isLC0*3~7.K as foilows:. -~-:::.:. "'._.:~_,,*,_ '.~~{:.!JL "-:~->.;*_,_c';;.:::*:: *'..-._, .~.--...,,*' _, :'. -..... __.: _:_::./.. *

**-~.: 0,:>;/L./~~'iCurieµtT~"LG0.'3.7.K2i:equires aniaxirriuin average suppression pool' -.. **

~~

~*

• ~

,::'.,~'.'k'.t;::~~-::'t~?;,;;,:~testirig-whl,~lfadds:h~atto*)th~ _suppression pool;-current TSLCQ 3:7:K:2:b :...... . _. :->~; ';: -~ ~-< :1-{f ~~,(:':?::specifies ai{µicre~e 't0.~".100°1'. With *therl)iat 'power ~ 1 % of r~ted therinat *power;*... -. ' ~- .,~*--*.,*r* ,,.._-*::~***-....-~.:: t:."-rh*-i__. ** ~..... ~ "j.* / ~., -". ' :***}~-,-1:-:~~~.-!~":~>:}:::_'.f:;i-~urren(T~_LCO 3_,7.K.2:¢'specifies' an'.increase*.~o-~ H0°F with the-main steam.' - -*. ~ ** :-:'. ;""*,..*1!'.'- ..... ~*"'*~-..,,. ~ ~"*" ~*

• ~*1..,_

,I

* '.- -: <- *:.-::Yf/:*~>-.*~~\\\\., ~h~0isolatiori valves dosed following*a reactor scram... * *. ---.,_.,. *' ;._:--:. --_-.:

~ :;~~'::.. '.}~-:~~~~i-{'.;d~{~~f>:;~h:~;t:f:t~!f[~~~: -:~}-~::!... :*.:::f;:t~-.:_:~:.~ 1 t<i~~-.:*:<,.. ;_::* ;\\;;_>~<~:~.-~*~?:~~:-:~!~,:~.. : __. *.. * '-::' *_:.>>~: ;* _* *. *;~-~-: .*-: <~."-~; ~-::.\\!*}:,_}'-.. ~f~~~::r;iSfhe;:proposed:T~ *EG0-3:7-.K.2-'revises' the limit of maxiniUni :average-*srippression _s I - ** ~-.: 0 _:*:*~-:: --~<t?.{x}:~~:)f.t,)::*;p~bl ~tempe~fui-~}g ~.. 9~~~:)~ additi;>>n, prdp~sed'TS Lco *3. 7~K.2.~* 3. 7.:K.2:b *.. : . " *.:/:_:*~~;._:~f~~t~;~~~~~~t~~-3-;i~'.,2,.c:;?f~"~~~l.~~g:fui*follo~s_::.prqpo'sed-.J'~ L.C0~3*_.7'.K:2.a spe~ifi~s an_--0 ** *.- -_":... ~::'.. ',

• *.. : -\\~ ~~::~f:}::~:;~~t~~~{'<1~-l!.m~i'~ase,to;~ }os~.::cluring-testfoir:,Which.adds -heat::t:~*~!he--suppression~p~ol; *,.* *::
• _.' :_ :~..

-.,_* ~

;C*--:.. ::~:;,;~~~:;;:{:~1~~,:~i~:i>roposed'i:ts,r;c~~?;7~~~2:h1spec.ifie~. ari).iicr~ase. to'~ H.o~.. With:thennhl.Po'":'er-* :*_ ~ - -.--*. ":- :

~... "- -(. -~.:-. ~~*,*,~.. ~-. *.. (!_:.<l,.J ~ -~* ~ *7... ~ ' t I i L > +....'..._... ~

• *":.*.. :,~:*:~~-r.:*.:::~"'.<:.::~\\,.~~>.S:l%~ofrated*thermalpower;**proposed TS LC03.7~K:2:c:specifies an:mcrease.to :_
• _ :; -. *,. :~, "*

;.,~.,.,J

• -,_,*:_.~*~*-,*':*-::.~*,.~.... :~~-*; ****,*~*-:,-.-,._.;.,,'-:_;-~~;,,,..-'..'*-r-.'l.',.. *(*.::**.*

,~,.._._ ':,~ '-$:-* -:.:*~'-" 1 -,,,_I

• ~

_.*..-~.

,.,_.*;..~t*.'....,

_

• T., {z-~s~;:'~~,:t*'\\'I**

1 ,::;-{ <5;:12021'.'.~with '.th~ *main steam* isolation. vcilve*s* clo~ed:fonowmg.j{reactor *scram,:*:.,:

• ~;-... '. ::_ *.

<~-:., :~:;~~~:~¥; 0 f~~~~i.?~;J;J~~I;t~~;~;<~tii2~211~~~-~"t1-ii~~:i~~\\~~l!-}::.. *i,;.; {:_::~o:;; i'.'.~;,:~f~I~:~~-~?i~_,:::~~,-~t~~;~\\ -~~}~~~~:~~:*>~:;;,:::_;.~-:-,;~: _. * *. "~-:~ - -. *. ~_.* *..re; ~t/:-*;:)r}.~r5 :Tu.~*:revfsed'~Ts'iuc*0~1;1.I(~i-'of.~:95<>f. *i:>r<lVl<les a'1llriitaifoil"oii:tf:i~ ;suppression~~=-~:.-":;!;_ ':.: :: * -:. .._.. ;."*'"....,.~ -:*1~* :.'.:;.::-~~......... *,,. **-,.,,.,*....,* r:'~"- __ !..""':.,.

• -*~:/'"_....,..... *.....

r .. ~"-~d~:;~;~\\:{,,:~~-;::*;;,pool'.~v~i:a~~-;te~pera~7_1}lat.~iis~~s the._contiii~~?~ c<?ri~~~iq~.~sumed foi.the ,.,,'_ *-->~ 5~5\\7~* }~~~~-\\)revised.safety~ arifilyses are -met<This famtation,ens\\Ires* that.peak priffiary -,A'~... "".. _,, :..,;,.

• 1*

1... ~** "'n?'j('.~-:-*~~~~ t.'.J~~..... *'-:'"C-*'*"*_.

• • *..... *: ~ -:*{,

-.~ T"'t. -:~ * .:,_l .~ '::*",\\ *.,. .-..~-r _: *-:.,,*':--~:.. ~*/:-.r;:::-~~~-L'.:1..::.:.:.con~~~t:pressµfe~:-~d"teIIJ.J>e~arur.~s:do-~ot ex~ee~.'~axjmum. allo~abl~._..- - - '"t~..:;~S.-,.:t-,~... ;*. 4.... -"'""~- -~.. ;.. .. ?*".... ~* .~- :*:: *.:. ::~;;-::;;*:z:z~- -~~",k;,:;~ijl'!:l~~:qurffi.g:a.po~atea:pBA,or*any:trarisient restilting-in"hea~p ofthe----.:--~ '.

• /*.::'. :. -

~~t,~*c'~""J..*";- _i;

• ~J.

I

• ..,c:;.,-.* *j.f'.

J'- '<,Ji ~-:~-~:-:*~ ~ ~~~~2. .';,;'.~~~'{*; I~':f::'~uppressiop~pooL;Th~~iricfe~ *of.-2Q°Kis.~onsisterit..with '*'respecno.. the reviseCl_.. * ,, -i'-r '_ ~.*::c;*,- - ~ 'i:;-:..*-.:~.-"="*,

• ~::..--.:.*.r*.~:*-:*1.

~*\\*'J... -*~.~...... ;,-*.,...;.. *---;. .. __. ~-...:-*:*:~**,_._... ~;;'.:-..1'::....__;-:f:'_**~~* -*-. *----*->.- .1*.*

• _. ~, * '.. ~::<~f~~~-.>:::~i;::?J5~\\S:J'_~_is_a,f,efy.~~ajys~s-~~-dt~e>.ntiri~f'.~,~Qi~~\\ir~*,adeqiiat~* F;_G_CSi.pump~ne~~p~sitive _suction.*:" * : :~ :-- -' <,

_.--..

• _._.\\*,~~.~~~;.::,:~:~;~~~;;'~:!:i0'\\ieafi';i-~t~valf~b~"e,~~~~~a~~~bi!,v~s-~:~~~t9p'.3):f~2:*co~tfuii~s-tO:.~~.~ej,1aii(: _

.. ~::*- 1

{::,-- :~-~;:-:< --

.. - "--*_:.-.-.' _!:i:l'.',~,-;:;~:~ :_f':'.z..::::_: 1lliitiat-'coriditioll$: a5slliiied~for-tlie;ievised.'safefy'aiiruyses.reqirire'inerits are;/*. *t ~-*:: _ - -*~ .. t .';..-.-.l~ * ~.... -'17.::;;~-.,~;--,.*r-. ~ ',,

~..-

....,_~...,..... -.* ~**."-~ :~ ~;'f. l ... *. *-:.:,,-;:~_.~;,~.'iiL,~;:*::{:;*.:.":°.7'.~*~,---ril~tained~~tb~*:pioposea c1¥lnge.'i~:,therefore acceptable for ilsage.. at Dresden, ----_. _.-:-,:*._. *_.'.. -.... . *., z:~{~ij jf~~t~~~~:~ti~it~S1~r~j;f~~~~t1;s~t~*~;:.;~~t5:~*~f ?~f :*Fs:'/...~, *

• .. '. \\<.
• '.-~~---~::*:;~~'.:,_~~.:.:... _':,-.;;~~-:-.'~<[lie.rev1sed_,TS,LC0;3.7_;K:2.a QC$\\lQ5~_proV1des*a-hIIl_ltatton on~the* -:* ?,;-.'-:: :--< :-, :-' * * << -, *

• . :'. _:_:. :-_,,"C(-~ ~(L::*~:;0,~.~-.* :~:i-~~ s~ppti~siOi:(J)~oJ :. ay~rage',teri'tpeiitut~,th~t.e~stire*s~ th~--plant Ji~ '.testing tie~ibij1ty*-_ :.. _

.. ::.~-~--:- *~;{~~~:~?'~i~t)%~"'.f~~anci proVides>matghfbelo~:~tlie?f'evisecLts J~C~Q.. '3.::7.. K.2. b>limit1<'.>{ '5J 1 O~F' at.-:, '_-::.. :... ::,:' :~"*_,_::' '~*

.-*~_.. ::~:~~/t:~!}1g-~({.}f~32t~~~~i'1i?~~~~jtJ}~~~~tJ~f -~~E:e-:~~u~~,q~-~~~~e.n:#.~Je~~g:!~::!ci~~~ted~~:.i~~2.*;~~.. ::~~z~- .. '-'"->>'*: ;,;7c'°""""f.<<:>. ~ r::*::.~*:-;"'.'i:tP;e.T.S 15CC:J~3_.f{.~;2J1rµitJ$"Q~,-~),m~.be-.r~stor~d..:'Y!thin 24 hc;mr~.. The.tune,....,~ -:.~,,,.. ;,_,_.;.

~<

~ -~-:.~-:*,.:;,;-~ 1

• "::~... *~'.::..'-_"'*

  ** ;"";"':J:i.-..... 'l.." 1"""

~~

.*~-*-:,'::::::;.lc-i-_'::L;:,;::..r~::-'""*.;~:!* :::.....,,.._.*.:**-;;> *.~1~ f***... _.. !.

..... :-:~ :*: *-.*-=-:-*-~*--:f:'1.-**. *:-.** --~ :*'.,;:_.::,~;:, ~._.._-.. ...... ""*~penod:lliaHhe.. temperature,1s_,aboye:95:'.P.1s.hnuted,such'iliat*plant-nsk-1s. _*... '..., -~--'.,, :-:*

• _.;,.~.- :.. *.. *

'~~"':... ..~.. '"'-'4-.~ ..: ""'".* :,.j~**-::. **~ J_ ..... ~.I"-.;!.,,,..... \\-~-..,,._....:.,:;: ** :*", "*.... * *..i

• -.*Y"*.. ~-*

.. *.. >;;--~ ~:..o":t~/1-t::'. ~'! ~~i!t::~diThe~:fuci~~e~ ol--2Q/F*j~,con$Jste.. n!;.\\Vith'resj>ecf to_Jhe_ 'r~yise'd. safety.::..--.-,.~-~--,:--,.,; '('.- ._':::,* ;;!:1..-:1=C, ......; -~+/-.,~. **~:~~;:,_~"!.,-~:-,.._:,;-.f:;::;.;;;'!:-, ~; ~;.!:i '":~:~~.. "':>>~ -;..7~ :::t, --i ;*~ _...:_!.~., 3-!.a:;:. I ' :;;~:*" * :, ' *:~..... ~ -:. :--~~* *,.....,,\\*-;. -:_-:-::~ * * ~* *..;~. ~~*.,* -u:,*:-~.'.,.:;,*,,~:*):~1.-?J-;:-: /; _.

..;:!;:1--"i~.

,-~,'..Y.§~.~;~g,~~Qnjili,.ue_s~tc?.~.ens.~;~~uate~QC_~-*P!lil!PJl~t-Po~1tivf'.:suction h~ad -:--:~~ :;:;, : !:: ;":. ~'~K "'"'"~"* fatii~l~~s~~:P.*..,, ~~l<';;l;P!i~~~J,'.~:n,)d*~~4~11~~11

• .*'.1 ATTACHMENT A

. -:."'BACKGRO,UND AND"SAFETY EVALUATION OF THE PROPOSEDCHANGES

• continues to ensilre plant. initial conditions ass~ed for the revised safety analyses

. *-requirements are maintained;* therefore the proposed change is conservative and.

.,-.f.. _

• _ ' acceptable for tisage atDresden Station. *

*.. --.-. =*~:.::.. -~

..., }:.<,~-~.~~.. -.~:.. :*:*

• -:*-'~*,:~~

• .:';~****:-~':.'.,:.: **. *.. _:.

~- -~ ~:.. *;,--; ~... ... ~~... ': 0..' "-~-. : :. y.T:~c*. " ?>t"'-<

• f-'. ;;:The :i"eviseq '(:~ LGQ-:3:7 :K.2. b of* ~l l 0 f.provides a limitation ond1e.. *.. *

  :.' :.:*;:*,*;:. **: ~:.-~~* :\\,r~~:;:;,fi~~'.~imppre'ssion pool averageteniperattire that ensures the plant "win be shutdoWn

. : '* *.. : *'"; *::-:: -~*~:-:' -;~<'. ~':.:**~;/?\\_:pnor~tc>.exceeding a temperature outside~oI design limits.* The suppres_s.ion pool is ....' :/*~~.:. ~:::~ *y;:~;:;~,;~*. *.~:1-)desigtied,,tc>' absorb decay.heat *_and sensible heat bu~ could"be.heated beyond tt~~lll11i~tf S!~~d~~~~~;1??J~~~f~i~kI~1;e * ~°-*.. :-=*: -lfa,.-'./~~-~:e~:._*:::~r:. :*a5sumed for the revised safecy analyses requirements are maintained, the.proposed :. '.*. :' . *.. : *~ "Vrft::.:::~,.;~/> 1 '*:\\:?":~?f5:'.* '.'-~,::chang~js therefore acceptable.for ~sage at Dresden Station.. *_._.-'.. : ; '. : -. '

~:-~.<~t;~:~~:;~~~f;t~£;:~~:~0~~~}~~-~i~~:~::~~{~:~ *<:;~*~.. :*~-~_.. : >*_-<f~:-.**-.>*-~--..

>-.-.---<,-.,_**..

.0****_.-.. ~_*:*.

,.~-.. : *~~.~--~:5*'::_-'l;,-.:>;,./.;1:.. 2 *,;_:~;:. 1~'..;_ ")fhe'*r~Y,ised,TS *LeO 3: 7.K.2~c *of ~

• 120~ proyides a limitation on the ---.

:: ~*_

. --. -~ ~--:*--..;i~~............,_.;..,;.ef*"';;*r-;*..

• • ...... ~..... *

.{_ ~.,. ~- ~:

-:_:*:. ':f:.f

.-:::::.~~~r-:;;r~~~(*~?--:!.i~:Uppi:<?ssion."pool _average.teiljperature -t4at ensures the. plant "is depressunzed pri<?~*.. ;-~* ;,.~~ :' ; '. -

.:*.;; _~*i:;~;,µ-.<£o,v:.,~f.:~'*t>!~:7*51}~~~*,~~~&the~planiexceeding*:aesign;basis mruomum.allowable *Values for.priiiiar}' -:.:*. -. *.' ~ : : * *:.-.... ~;2*:t~-::.;.i,1~--*.-.:~'I-'"-'*." ":'t>.

\\l;**:"'~J.*.,...._:;~::. f)-'--':,,

• F

-u /. ~ -i

• . */::**'*!:.-{#::;q;:*:::7Ji*.::~,:-::,.:-'.£:~:<.;*.*;containmenftemperafure or:pressiire. *1f plant-blowaown*were*to occur.with the.. ~~.. --. *

,:*.,;',::::*,};../:fii:~~:_;r.;!?.J:'~W.:*~-~~::-.;::-.::.";;' '.- -~_(

• J~_'*!r..,"","*

--.l _,.,~ t L .,-J - *~~-.i...,.. ):;;::.i?.~.~~ -* _

-,~---- -))~ay~rage*-st,ippression,j>o.PHemperature.greater than IS LCQ.3.7 ;J<.. 2.c, maximum::.-.:.'.:_.- :

• t-1

--;.-,~---~~"' ....-~.**""i--*-'-*-(:~ ....... '"v'. '.- ~ ~ ~* *.. * >i*-*

• --*~~~~~:..~-"-~:Nf~~-~~~~?.~~b~~~s4ppr~~~i.?~~ P~?:L !~.ip~e~atll!es.c<?~l~: ~~ ~~~c~e-~e~. ve~;f~p~d~~.. : Th~:':,)'(,~:~*.*"". ~,, ~-'.'* *-.

-i;;;"'-

*":'.;"'l-fJ.:~r-** --£~;_".(1,:;.;~mcr~ase'of'!l O~F.:is consistent 'With "respect-to--the revised safety analyses and* -

~~?f\\t~z~~~J~:~~~;;.~;t,f1*~~ffe?:~~~~~~(9}~s*~;~cieq~~~.. ~E9c~--~~i>n~~-~?shi:~:s~c~~o~:.~e~d.. *_~~~ca~se._/~.. ~'.1~~~~~:-.-~-:~*:_*-_.__ -~ "'~i ',_.;_;~-,.:*fh~!(~"*;J.:~::~;f~'.?g~_~r.~yts~d_,TS.~L_GO..~,.Z~K*4:~ _ ~o~~~es. !~ ~n~ur~,p!ant}mtl~ c~~ch~?ns ~s~ed :fo! * -*.,;. :. > * ** . ~.--~::, ~:... !. ;S<;.7-f. ?t-~\\~ &.",-~~:-r~: *;:;the reVi&ed *safety ariruyses *requirements are maintained,* the prop9sed change, is'-_-.-.. - _.:;..,:).,~".~1~_.:,~~.::.~:.~--*.. :.~::1-.. _.:-l"..:<;~-.';iZ\\... _-;...* -- '. - ~- ': *.* / t,......... *

• **:*.~...

-~.-

• • ~ -~~...

~.... -'...... * .~: '.<~*'.*..:,,.~>'::.'.*:_._::.~,'?*~ i~~,::;;~f<.;~:;;*,..

• therefore.acceptable.for..usage at'Dresoen.Statlon~',; -.,, :::, :- _.. ' *, *... *-

._;~t-i~~i£~q%ik+~;~:t Yj1f~~-:~~i1:~?~J~;f6~~~f:t;~v~;~}~~2-~~E:~'~:::L~;~/:~-~<<~*}.~;,--:.,:*~~7~:,~:_:;~-~~:t.:~-~~:~;,~~~ 5 -__.... ;.. /*:*>:*'.~:<-~~;(~.'..<~.. ~;:~~r °'*~;:-~~~::.;;- ~~~,:~.. ~:~;;.;.. 'f-'{~:Ieoii1Edproposes\\fotevise'TS:3~7:K Actions as.follows:*:*;.. t,-; *. _.. ~,-.-:; ****.. -.:*.-:~-... ;.. _ :,-::

• i~~~~i;~~~~~1!~;~t[ff

~i~fi~1~~3!fi~-:~~~~~g;~~~;;;;:~~.t~!~~~:~1~;R~~~~ ~;f:~~~<~~>*:: :::; ::~~t--~;~2,:?~:1\\:;,t, ~'-~':.-~~-:_..

• -~--_ :

... ;- :_ ~~; ~~*~~ ~~~'.:~;;~ ~;-,~;~. ~~_:*'~: ; ~~*'f ~Tt-~;;.~t~~~~-7$yj~~*f;.z/~-~~~~§:r~~!~~~~-2~~:~J~.Ac~~9#::_{~9~~mei:ifa.;*: ~~~ures,.th~* suppiess~~n po~tis_ rest?r7.~:-.r~::~.. ~ *?~,::,_ ~~::;: * ~~<~~:0:\\~:~~~-:~.~s--:*:*~-r~_,fet~:Hf:-)o~operable~condi#oriS~in 'a~tiriiely~~aruier wheri-:Potentially adverse system:. -~*--'::' -:.:. ---~.:_,**Y\\ *.-,:.'" ~-.~.._A*::.t..*).,:..";t~~.. :;-~2:.:;;!£:~:.*~ :, !-.::1-t.....:.~~-~,---~ / t~.- l --~

• n
• ~.).

>~ *: ') ~ -.:-.";:'. r* ** ~ '.s~:-:~;~:;~~~;z*.:.:,~i;:i'.~:#~;,~.JL~-~ _;;~,;conditip~:~e ~~~~nt~ ~µrrent.TS,~/4:7_:1<, Actions*i, 3; 4 ~d 5 are proposed to*:.. '*_.}-:-*.-:-~:--.-:-. {:;: :'. -~--~->~~{;~~,:;_~*~f-~S~E~;;~~:~~*:if~be.revised ~o~amtam :consi'Stency With the proposed changes to TS:LC0*3 //.K.2:. ->-f-.".-*. '. ~-*~*~~~-;.:~* ~-~'~i':~::~.. ~---~~/.. ~-.~..Sift~S..~.~~..... *:-:*-..*::;.. ;i,-;:;-~~<. **::**

.-.,

;. f-*

• ~ *. -** --,.

~.;:~*':-:fi#.?~~~~~'.~;,~~~{~1~~~5~*-~B~~~~e- !e".~~.e51* ~~tlon ~e,qwremen~~_q9ntll!u~ to. ~~U!e plant imbal cond~tions

• _ :... :
• _c.

. r. -** *-*-**~,....., r -**., y*~""""""'~'* *""*Po/.-......,."" *'&. *,th.. * * * *' --,,:.-s:-- _,

• ... * * -* -.- *
• d *th* -
  • -d* * * '""....

.--".. ~*~*':_;.:~;~:1};:;.~~"'0>'if.:*.-:::.~"\\';:f;.**Jf~-::a5surhed~1or. e:revised*scuecy:*analyses*reqinrements.are mamtame ;* e propose -: ,... <*:{*,. -:r.~.z";~:--~.i:?i*:"'!!"*"':,';,.:::l*:-.,.~~-:*.*;,;""-T*'~~;,_*'..... *.r:.*-*~'..... * *. ..-7,,,-,l",.-~t~-*.:-*~:...._,_.,_.~......_ ... *. -. ~ *-..... : _.,~,<A-*~* .~

• ~'

-~ \\* **

~;5/~~,-~.~..---.-

-<r~~~:-.;~~~~,...

hatj.g~s * ~¢* tlier#*ore_ acceptable for* usage*atpresden Station.. f'~ . :.-= :, *. ~.. ":.. ~--.

'9-'K"2* ~~;z-~'2 ___,_;-~f7, K72'lV~rTK'2'b(lf4'J=K2 b(2).. a~rTK'2 *. r.;

• ----,.-~., -*7....;,- _,"]**.-!;.'.;;:.. *.

.. _.*.r*.. ~*

• . : *. *-.:: '!.~1<.*..,._ :... :.***.. ~ -~ ' '

~-... :* ~- ~ ~ . -**"I ATTACHMENT A. .l ~ *: -~ . '.... ~ ..... **BACKGROUND ANri SAFETY *Ev ALUATION o:F THE PROPOSED CHANGES ~ - *,,. __ i:: ... -'..proposed to be revised. Because revised SR continue t~ ensure.plant conditio~s . *- assumed for the revised safety analyses requirements are maintained,. the proposed ..,:.. *.. ; changes are conservative and. therefore acceptabJe for usage at Dresden.Statiqn. 'l

.. ~:*->*\\*...:;:' *.

1..... -* *- . c'*.:.

~,_. ','.

.\\.. ~. ~c-~.The proposed revisim.i of.the second p~agr~ph to the Bases 'c;>fTechnical..

.. ***.... *:*>>.. :.** *,; ~:.:-~f}.'..L_;:~ '.:*;~ '.i$i:>ecification'_3/4. 7.K* clarifies ambi~ity.regarding illitiai'analyfical assumptions _ :* :..,:.'.yZ~'.;):~;*;j:'.:*:~z(:"?~~l;S:'/.-,{Le.~:--dOOO.psig) and the pill-pose of the.system (absorb heat from safety/relief

• • ,~,-:J;~~~~i1:i:;~_'.t\\ll~if ;tt~t~~;i:"'~~l :e:.~~~:::;~!~~~:~~~;~;r:J!:.th[1~:i~ ~~ed:* *

. _*. ;' ::~.. :-~*::'-; :* '..'~2.,_:;X\\.\\. ~;\\: ~* ~::;)The.pfoposed.changesto the Tec~cal' ~peCi_fication_ Bases.for Sectioil,3/4. 7.K. *

• .}~;"f lti~~~~~~~1~~~*~~~::~~~ti:o, OoJ;}\\tpl;t.~e~ 7t.*.~*~~t?or

".;~'.":-..:::-'i:'::*":?:.~?-;ci:cn,,~;:~;,:;_:;*:c1<.:;:*:<'b~'ffhe *proposed ~rev1s1on.to'the*fifth paragraph to.the Bases-of Technical ' (:~~~i~~~~If~i~!~~~~i.~+/-df ~$P_~~~fi~atjori*,~14~ t~ .. cl~.fi~~--~bigµous language *1:egarding the frequency of the -f.=~*~_;,:'!?f>_\\,\\;#;,?-.::;:~/':f;:~:j~plruit smveillance*reguiiements: '.The proposed changes from daily* to.every 24 "

• -**t~:.: ~-;;.~:."--~--~~--.;._..;;~:'fl~:.. ;',...{*~~.'~~

~~,..., 'j***<..,.._. "*,j-

• ~. :*.*-...

~:.

,..

;::::-,9t:;,:;:;;:,~:".;*~~0t~,~~:.~~'i.~hours.. are-eqwvalentanij* admlinstrative m *nature, such that plant safety analytical

.. r.,, '"'"}- ~"'.°..::..<.~7--:( *.*'*,t;t_1.............. _.. __ . :- !?:.~')~.'.~:;.-{'.~"1~:,:-;~::~::~:~ti:'.;'7:*; ~::~~~l,llllp~ioll.s~:.rii,argins,9fr~sii:ltS 'art'. *Wiaff ected;' )be p~oposed ael~tion. of _* :..

< "~::*)~\\:i.*:~ii)\\~.\\~r~~i:;'.~;"!;2~:*~,:fefe'renc'e'1o ext¢mahi'.isuat 'examination following specified events relocates " I

--<":'.*::--,,.j:;:f:":.!*"*"r!"~,','::.::-~::--*":.~*::'_*,".~... --**-**~*-.. *-*.

• -~.. **

\\ \\,*;_z-~;-t;;L*j;.,~;::;:::1~:-;-~;::;~;.;::Wom.i~!.i6n tl_iat)s: not ~appliCable to any.Technical *specificati9n -limiting..'.. :* - *,. . ~...

• "'~:.v

~ "'*~~.-.... -*.-~..:..... ~ .,...,...;;... -;,°:t:*-:~**.'1"7-.~~.1.,.,_. __

• .~.

~-. r --~ -........... ~* ~

c*~*.. -

~~~;-:~t::~::~f~:~ ~'\\~~0~.~.. _c~n9itiO~;f~~:~perat1on, ~actiOn *s~tement 9i;* sllrVeillance requiremerit: The

~... *... _ -.*-. "..... _ _-.}~\\ .. rfiAt!~~~~-~. ~ ~-i~I~~i;t~f~f~h~~c(~~~i.l!~c~~~k~~~~~~~n~ desc~ptfon_w~ielocate<l fo_ the~_plant _UFSAR-.'.:* .~,;:-,::\\ >::~ :<.*{:.~S~-~\\'~~~~~~~,,~)~s~}~-~g*'1ie'u~gra~e:t~_ ilie ~~c~c~--Spec!fication*upgiade ~rogr~_(TS{.!P) and :. -~<.-.1~:.<*~~<<~ ~:~:"~:'"':'.?:*,.:;~~*::":::;~a(lyert~rttjy]e~ *in the ~ases.c*-.~ *such, *coniEd *proposes to relocate refere,:ic:e to -;~-/~f~ ~~~::j'.fi~~+/-;~;:~-~*~:*;~f~'.'*:::~Y:.. *~;ftJiese,.req~ireme~t5Jo.the piant_lIBSAR. ***The* proposed changes to,the* Technical

• • .

    (~:-;:D;ti~,~.:-~~~~'A~:{~ ;, /:-.::.-:~specificatio~; B.ciSe*s for secnoiiJl43.Kare administrative *in nature *and do not. * -

• ~*.;..->*~::-;-.~.0";"!.*t.~*.;....=--.t;,'-.~-,,::-,i~~.:f*~.. --..

-?.. 'f*'*+/-;,,*.:*

• ~* *.* -.:pi:.:::*.--*;:..,_.. __

I 0 ~0.,~:*.:~::'~*.;*...:::.\\._¥~V~;:*~~;.,,',~0oi0\\;2adver8ely.affect plant safety.arta.Iyses.. assumptions *or results.. * " . :.*\\~~-~:J;t~§i\\.~~;:1~~;5~~~}{.}~:i~~/;,f:::~; ;i:{..;~j~~~~47~*~'. if~ii*:~J~ ~:~"::f:2,; !: :_~ :'.. ->~~ ; .. *:.. --. :--:. ;*.:* ~*~:\\ : ... ":.. ;._, :~,:- ;._: '. *_;*...,...

>~~

,."<:;;.[:~ S'.:{~~~~~'.~~E?.thipropoieCi"'¥~isidrl t<{Tu~--~i~:~a '.~~~enth*p~ar~iraphs.to the Base~* of.,..:*~; <........,.:*.:-;*

• -::':-1_*_..:..;

';-f,.."'.,fli-'~.:-$,~-'f..:,..-.""--:; **. - *.:._. _..:-*r.~.-::--1;_0"~*',_..'...:..:,.;*,.~-

.'*'":-*<'~

.-:.._r,'.*- -r":.*. ~- .:~"'.~. ':." t~L~ ': }',<~'::4~:~ffecl@.~al.$pe~_i_fic~tioif3/.~"~1'.K;'U:poate:s"the. l~guage* withiri *the Bases as.a result.' - -*.-\\. * ('i~~:/~... ~~(. ::;~ ::;.s:I~6~~~6nile.<lesfgl{ ])tlsifreco~tiiuHoii~etroitS:~:~Tlie.:proposea *changes ~-clarify tilat GE'-* *. : -* * * *

• ~*--:..;.;i,:-.*u.<,..,. ~, **-.l::t*,-;;;.,r-.. *--~*~ *..:;,. -*

-. r.., '

• ')

'*~/!/:~~;_<::~~>;:.:~:,:,:.;i~::./:L:n:::r:: ~pq;:3,0832'.i{applfec;I 'for*:thrp1aiii *_safety apalyses and.eliminates"local. * * * -

.i_.,~_=t;?~*-:~:::i{~~:~*\\:'~~:>~f~}'suppres~ion *p~ol~b-oi,ifug]mutatioris.)n addition,~the reliance 'on containnient "., :.. ;.

---- * - 1,, ~.-!..,.

:-..':>-

i=.. 1-i..J_..,.. __ I:'." i.. i,'>',',.:-L.. ,.._.. ---=., *..1 . {, * ~.<:' -" " *-

}*'.=:-:*2;~:.. ~~t;:;*~~~f2~"-~ <j *;./ ::q:~~rpr~#irre.fo __ m.aiptair(a_gequat~ riefpositive suction head for the emergency r.t*

-**f*~* _,t:>-..~!.lo....... £-1,.,.. ¥... ""~-~, r-r.---:.l~.... '~* -~.... r.:"* -* :-_* '1'"';'"._.* ~ (~:S;f.:i~~;,4'°!-t;:;:::~;::~~:,: ;~!o:.:-t:.-:\\*cpre* coolirig 'syst~rif p\\imps~js: expliCitly described. The proposed 'language '. *, *:;. ". ii*~~~-~:'(;~;t~~~~~*it~~)~~-~*-~eMlirm~ *ilia!.-ilie.piir1ios~" of Jechni~hl *sp~cificaiio~.314 :1 :K.. ls :to _ensure th.at" . ~ ..... -:.-.. -!"'*:._:~:;i:i,-!..;.e-;;'"'-.:~_*,;_;.:-:-:;--.:;:.,~:... -.""';t,:.J.".:~,::.....:*;:.* ::i..:,. :--:"'-.* -

.. :._..;.. ~ ;"1.'

~. ,~* ,..?:~~~:~{;~::7:::::+/-r~--":='.sc~?.;-:-!'~c:ontainn;ientcond14pn$"assumed m th~ plant-safety:analys_es are mamtained: Th~". i*... '/!!~1!;_,i.J.!;'\\lf~'.!-'1:f-* "*<.'l:'::!~#*11';:~*~;'.<-*'*'I*'"':"*;.,~-*,,,.;!-*~'*~.- ,*_*-\\~ <.~*.... -.:.~;;!.-<< ~-.--- ~~* ..., ~ 'l: ;* '""*"*" ~"*"'"'" ~"f:$*~:{~t; *:§pr6posed~chailges*1to*~fue.~Ted1iiicaI,SpeCificatioriBa5es f~r-se.ctiori *3/4::7~J(.are:* -*

ATTACHMENT A,. *

• .. BACKGROUND AND SAFE.TY EVALUATION OF THE PROPOSED CHANGES
• '5.2_
• Bases of the Revised CHRS Operating Parameters...

5.2.1

• Limiting Accident (DEA/~ No change from <;:urrent
  • :.: iicens1ng* ba5is. See
• Sectio~ J.3.1 * * **

.*. -~* *:~~-*:;;~.\\/:~; *_: -~r....

• = ~-

.~*..... ~*.*. ~~- '*~. ' .. ",.;_- r< :,~ _, ::*. ':, * *:: :., *. -*~.2.2. Proposed.differ.enttal pressure for LPCl/CCSW-._ 20 psid - In support of .. ~>:>-' '. ~ ;~~\\. -,~-: *:.-:* ::<:-:: :. *.*. :the -licensing ani~ndment; the differential pressure~has been evruuated to assure no ., :~*~'};:l<::*<r*:. >*.;:'. ~.. ~<leakage irito the *_ccsw system will-occur." An analysis of th~*pressure losses and .-. -,;,:~{::~:~{~'~l*;.;~;~c~:;:.,, * * ** :~::~:._*.their ~i~~buti<?n 'iil tlie _li~at: e~chang~rs ha~e been _ma?e to *supp~_rt iliis : *

• '* ** _*;;:. ::c.-:.:.lc-.'**". *
• . *evaluation.* The analysts ts m agreement with the-pressure drops shown on.the *

-~..

• -.. \\::;;;._~:{~:*"-:\\-.~<:.~':..' /:*~ :_-~ <* * *.* ;The'.. quantitative-relationship between the mllµnium pressure difference *in * -

.. ~~.;~-;~~~-f~i\\~\\~-;:'*\\~,~-:--;*:~_:i"~-')iu~.l:PCI_ 4eat exchang~r.. ahd_ the.pr~s~ure-.difference,-at-the point o(mea5urement... **. * * *... *' .:~.:~:/:]?'f~f3r?~3-;ft;.t<<::-~~0~-'::~c~the :~#t.i>i#ing~~f the heat'_ e~changer ~as thel{d~te~~d?Jhis c~Iisis~ed: of_: '.,'.. *. :.* :.... ;*:* _:_". *:. ~/-/:'~i; "'::1t{/.:_*:~?:,;-:t._,; >** ~ "'"applying'Bemoulli'-s.-equation from the point:of rnitiimllin: pressure.difference to_ _. :_" * -

~~/t:S~f{:;.~:~~1li:&};;:!:/:~,::~~,~;,~.}:\\::tb..~;e~fr'.pipiilg~~:V~fug tli~'.*veridor daUi:giv~ii:~bov~;a-:me~ured pressure~:-

.,, -... : *. *- * '.. ~: *.:-* * *

'.~t1ir~~~~ 0J\\~t~~~;1~t~~:~t~~&~:;~~;;~~~~;~;~~d:.rr~'_::ri:,~~:w.. -***<:t '"._.-* .'/* \\--**. '. :-~~c.::;; f'~-~--;.. '": :-:.. std~ pressw::e-t<raccount*for. the-po~s1b1hcy_that the l~alcpath is 'at:a flow *stagnat10~ -._..._... -~~-*~~_:\\'.~:';~._*:;~?:.<-':.. .. _; ;pqiri~ of~e sh~ll si.de_fJo_w:~_.:using.the rilcilcimlim veJocit)r~*tlie.stagiiation.pressure.. *.. --~.J-~~it~~~;~c;1,:~~~1~;;.~~i~~~~f~~i;~ffi~r:~;!~=~~~P :~:>~: *** *i***** - -~"<";.~~;;*:~\\*:."-~~--'<i:::::~*::-,.~-7:.i:**:'*,-. ::;:_::.'-.. *'-For zero])ressfue.ciifference.iri'-tli(dteafexchanger 13 l9 psi* --, * -... .*._ ( *.. ~~:~jf {~~~~~~*:;*,:~;.. ~~:~:;~-.~~~: f ~ ;_'.:.:~:~~z.~;f ~!.:~ta.:.,~~ti~#-~rf(ef~i~~ 1 J~;;f ~:;:~*>\\ f :: ;*::<.-:,~.\\i*<~*.>* \\ * -:> : -_ :_:i _ * -* -........ ~ L *: *. *,;:._. -"*'"""-~.-.....,.......,,. * **... *.;.,,.. *. *.. * ~- --Calcwatic:inuncertainty'".. ".,..,.7~2*2s*psi,,.... ~._ :*

• • ,-;.. -. ~. ~'.

• -
• I'

~* . -~.:.".

• ATTACHMENT A

. *. BACKGROUND AND SAFETY EVALUATION OF THE PROPOSED CHANGES 5.2.3, CCSW Subsystem Flow -Minimum (5000gpm) -In the case ~here* . two CCSW pumps in one loop are running, CCSW flow is throttled to maintain . the*pressure differential discussed above. A calculation (Reference (3)) was * . performed to det~rmine th,e required ccsw flow and corresponding pump.

• .... *
• discharge.pressure needed to maintrun a 20 psid differential pressure between the. **

..*. : LPCI :arid ccsw sides of the heat exchanger.. The following inputs were

• * :* *

• conseriratively utiiized: * * :.. -'.* '. *

. '. ---=-- ~.. - : '

• ~*!..

. I \\ .~ _.,_ :... *~_-*.-.(I) '. The conUunment overpress~~ WaS set an 7.psig.* As described in Section -4:2.12, the.maximum catculated-value was '16.~. psig.. , - *: * >>_:(2).. : The*CCSW:pump curVe"was adjusted downward by 1.5 psi based on

'

:_: : '> *~_:*_; ;:.'.:."*.. :

,~-. "~ ~ '.):' : .<survei_il~ce test da~. of the pump With theJow~_st developed head...

• \\.;.

  • • • *.: "-'.... -**

  • ~::-::... /0) :.*

>~einaximum:LPCI puiiip.devetope.dhe.~d:ba5ed on surveillance datiiwas**

• :~
• '.. **.**;:z i;~u. *

'.'.':e~. ~:*.*: ">.:'.,-~~,*:*t*~;~*+\\2~a, ;.. >C } * ..,.. -:~~-.~** : /:~;~~'..: :.' :~ *5.2~~f '.ECCS pi/11Jpfldli1 *,~ijiiirements:-(CS.565014500 gpm..: nominal) -- For the

~::,. *. <:~-:~}~.:*:~*<<:;:~;* *::.. :~:i\\-~.*\\,.;*sjnglefailui-e,.:;upe1*J~oop:.se\\eCi::Cog~c*an.d:s11ig1e Ffiilure_LPCi'injection;atwo~.*.*

• * *.'::; /'.'/~:/'L.. ~JtiJJ:*~~,:pUinp.~or~'~pray;'fl~W~~idi;3oo~*gpm i-esitlt;.lli:a 'PCT: of:S2030°F at I 65.4. *. *.. *
• '. * > */_:~.:
• ~. *.' 's~conds.(reforeii~e128}'.i~'tlie:.~10;cER 5,Q.

.46.:anaiysi~*;* *-*- .. *~* :.. :': * * ...,,~ *. \\~:.. - .. '. '.. "; ".:?~'.~~;:~~~-::).:?:{'~~~:,{~t:lD&~.;~~'.J:~{:.~:*;~~~0:\\fi '~L:i~-;{r. >F<'~\\;:'._, ~.. **...... * ;* *:. :*. ,, **>:}<.

• .. ".,

  :*M_aintaining*~ :wa.t~r~leyer~i~tWolhfrds*,cqre:height}s suJlicient to maintain..,* *

.**.*:** _:**..,:.. _{:.-.*.~.-.. ::: **.'~*:**.

• ~';: ~-cooliiig:f9119)Vmg'.ii°'~LO.CA;:;~(i:~ference~i.:3o~31). **Tuiscor~:level_was reached in

\\' *:::i.e~s.thrui'5 ~ute~:Wltidi'.*~6ns~rvati~eiy.,asswned..,~~nstarit"ECcs flow at 9000. .. ;*:;.: :.gpminciuci4}g:a);~ag~*:of53.S_:gpmi,Beyo~(L5,iriumt~s; an ECCS flow rate of .. * !*~*:.. **.. :.*.*>\\'\\;/*) */*1500_gpin.~~~{determirltidto,:be'sufficienfto iri:alntfilri water level at2/3.. core ~:-/~~~ ~:*.. ** * :.'. ~* \\:** ;, *:* :>-. :*lieigii_t: :.:~t:;:t0:9f;.R~~oA6-_anitlys.~~ wai~evise(to

• incC>rjJorate a.leakage of 948
• ~~,8~~}~~~00
• ~:- *,~_*:-..:-.:*.-c?

_.<:.-._ \\ _:_-') *>*: ~ ::. ;.*,::.c_overag~.:.. at 2/J~core _hfagh.f~d~rerno:Ve.."decay*-lie.at after.co.r~ reflood. ** _c.

• '.:*,~, :-~L~:.~~?.

~~'* ~:_;.\\'3:\\::.:< ~~ *.*:::_~:~~~i:~~~c$:~3~.. E~t;~~~z?t~,~1;5~h~~~i~~~f :~~~:.::f t:~~'ti:~i;)~~:')~:-~\\>>l.. *: = *.. >-.--: -~.'.>*:;. : :"*. * * :, * *.*

:* :_..:.. :'~: * ;:~._ *:.5,.2:S._::_':~C.QSp}1"ifif2Jlqw'fequlrements;'(LPCL5QOp.gpnf-.. nominal)-:- :No change

.*.** ;"*5.;.. :J i,r~~~*c~~W~~'g'~~*;:~t.~~~¥~:2,{s;' ;:;~L: :~.. * <*;*: -~ **.*~ * * *.. ':.5:2~6.*:~~->>:.'F_io.W.'tn;fru'Ti1'e.ntatiorruncertiiiniies (n0t'inCiuded).:*1ristrument '.~~1';~f~~:'....;*.., * * ** :'~>_,., **. . - * *,. '"'*-~ :'°"-l*:...-~'\\".._.. '-1'~'_,.:.

• • ~
• .-'- ;. f" ~.. :i_ r J,* *'
• I~ *

~* ". "':* * *.-,, '"-:_* ** c . *;.. ' *:: -.~:.., ~'. ..* \\;'; '. ' .~.unc~rt¥nties -~~~~ot~9~9~~~~rf oy:irr s:*pr9p~st:.d._li~_~nse :~en~eil~.- ;~Rather, -_* -'they are'l>emg.acco~ted**for.in the'Dre.sden Station"Setpoint Control"Prograrp..

• ::.. i_.::i:;/~'.*::~<:*.... *-* ~- :~~-..-~ ~.-.:*~~;:-.*:_)~'~:-~Js.2:?:;:~(L..e..'Q1(1f~di~iixciz;;ng~r.'P~rJormance,.:. The perfoi:mance *~f the heat

~~~ 1t*~~' '*. ... :._-.-,_,.,,,,..,.-,~*.... *:':-.

..*,;~

~~',:. **_"::f.:;-".,,~;;~:P...::.;;:'..::-;~**\\:EPGI,!DffilIIl~--flow,.?QOO.gpm (See.~ection 4.~.. 5) *.

z.:<2.~;.f~:-.'.:::-~-:~~;;... :s**.-.~~:&i:.::/ ~£1";~~,::~.;;:,;~~:a~~ccs_w,c.illuiliiiUffi:t1c>w;~~ooo.gi>m: csee'Sectioii 4.2.3),. ,.,. ~. "..... -..

.. ATTACHMENT A BACKGROuNn AND SAFETY EVALUATION OF THE PROPOSED CHANGES

• .. Maximum tUbe side* fouling resistance, 0.002 °F-ft2hr/Btu Maximum shell side:fouling reistance, 0.0005 °F*ft2hr/Btu Number of tubes per heat exchanger, 2512 (6% of tubes are assumed
  • .. * *.<<.*:"plugged)
• (.*

. '** -*. ~.. -*; *.:.~-. : ::... ~/;._-:r. ':'. -~ 2 -,i,,_ ;;;~~;,;~~ ~~~~Y';,~,

~eat-tr::~\\:::::::::::::: :::tfttransfe; cap~bilitY-of71 xl06 - - ---

z::;((;:X::}A;(,,:;~~;~:./~;~S:: ;:,.. :~... :* i:.::Btullir. and a. vai.ue of_K~. u~ed. in ~e containµie~t: analysis of 2s.1.7 Btuf~ec\\. *.,

-: :)~ ;:.*,:Lr(*,:,.K*1:::*, *.. \\..:.:... :, -~,., :... * ,.:*:~~ ~?.F : :The methodology *and ca1culations *u~ed to deriveithese values ar~.. ___ -'::r?f il~~~~i~feJi :~-f i~it::;;~is:us*:2~AZ;JE~~L-;n1e1 LpZami;,;,:-9s,°F-.L... -- '.~.:_*--~;-_:. __ -~-:-_ ; -:;,:.* *~i~::.**~~~ ;~~r::.:: * .. ~:.~[ :~:,:~::.~-..;f:::.. : ;. >.'<< :~rlgincll lice~sing 'basis;*with a Techµical Sp~~ification "change td TS* 3.~. C ;* >*.. ~, .,... ~- ;::.*.;:,. -** ~-i'"-~.-.::~F~-;,.\\. 1-fi-.,:'*.,;,...;~c,:.. ~.~:t;::""'**,~.... *-:_ 0 0

'."~ :-*,;:t..... ";]'*_;"~~-z:a*~:'-... :-"::*~ *,:.... *.-:.*:-.*,_"-:~ <<-LCO, revised fronf75.. F to 95 E: The JUsttficatton supportmg the * "..

~ s;;;~:~~:i~~f ~;~/ ~~-::};:.:{ t::"~"~' ~~-~~.~~~~~epuibility o(th~si-propqsed changes are prest'.nted ~* Se¢tion 4,.1,of this.. _ : ".. -". ".. -<. -J~~¥1i[~£~:{.i~-J-tL/;=t: ~ *~ ;*_ -:. ~*- ~::*-'-~:.( '.;' : _ ~* -.. >'{.- -. ;,,L ~ _-: : 2 <_ ~-- * ~<--. --~:~*~~~~.. r*'.::..:~~('.:1::~;:;".i-;:.?S.<=*:-'.'-:.::,,.,'?~.. :.*-*-.;_.. * ---.: * * *5.2.9 ->:Maximum Normal Suppresslcin poo/.temper.ature lim'it is'< ~:._ '<<,, ".

,_)\\~&'.~::~:2,;/~~t'\\~(:.,:":X;j;f~:ri~.;~2.'.~ :.95.°F*- Sanie :as orlgirial licensiiig basis~ 'with Te'Clillicai Specification.: *;*

~ -,

... ;;'.~{;i'.~~itt.~:L",*;:*;~:3~:~~-~~c:*:~~ ch~g~- to_ TS-.3~7::K-LCO,.ie~i~ed from*7~:llf'.toJ5-~." ;Tu:e justificatjq~.>'..~;:: :*:-.._/::.*:-~... -..:*::.... _,c ~}?ki?,*;?471~~~;/H.:)~7.:~;~~~~*:_: *Supporting ~e acceptitoilitr oftiiese i>r<?pos¢d.. c_iui~g~s-_is.i>resentea.in:\\:~.. >:z;-.:. *:\\'.~::~-.. :.*:.~::.:. ~\\; :*_.;~~!~f 0¥.i~~t~}0~;!(:'.~'~::~ ~-c of ~=!~p~:- _* -: ~,:;;.' ****:~:;\\-;f (-' :c:;:>;.: "~" lt:;~?:J:i,~: :',[.~ ~-":<,:-"~!{.~';~~-::.~"'~*:~:,~:.; ~.:->;:-* _<< *: * '.-.. - ~~*.. * * *-::.-.5.2; 10."Pe'jlk Suppressio'}pool Temp -'<,,J 72. J -~~:fo~ NPSJ:I - case. *.. -.-,.,. --': *_, ~ ._,,~ ---- ~* .~.--~~,...:">). ~-- "'l,. ~ 4 ~* . -.. :,.:_:._:-:~/.,./.:~~!s;;:~_-.-~::*:t~"} ;.:..<,J-:..~: << *:* 2a.1-in Reference (4) when coupled with minimum ccintaitiment pressure;. : ::*:.' * . :~.. :,>>'f~::~ii1[~H~~:~;:r~~~-'fo:~.;~;~,;-;>.. :-.,o:.:'*<<* -5; i 76'°F- 'case* Sal':iri Reference (6) for.oihe~ p{rrposes such~ EQ.'..The:.,._..,~: :".<<.. "..: ~~~ffi~~j\\~ ".~. -;.:~-:~;::}_ -~\\3::2 :*~ :'.*'<<'-,._-~:j':'..".:-: ~* _

<<validated m comormanc~* with. the reqtµrements of ~e GE Engmeenng

~)-'-*~*

.o;.:t'!::";;":'*i.4'~'........ <..... *~-*..... ~>:,?'o

• ~

,-~ f.~~.t't::~};~:*,~%:<<~:~; :';~=>~--;_:<_;~:{ __ -:.. ~":..'-.;Operating *~roc~CIW:es.: In *additioti,, the-attached calciila~ion, *GENE-63}:-.' :.-.. ~- *:,; >-* <<* .- ~*--:*:.~:-**/*'\\*~\\*\\0*--~:;:<~*:.. ~~-*,.~~~ ::.-*.. ~ *> * -'.Ofl201193, '.'Dresdel1NuC1ear.Power' scition~--unit5*2.and*3*~:containinent **~".:* ,.~.:.*: . :;.. -~tB~t.?:&rJ~l{f~~:.;:?:i~~*~-;.. r:r,*~*~*::. '.*::;Ana!Y!?~S of.the~~~~;~99A t~ Up~~t<th~:~D~sig11:::~a5is 'for the *:.:.. ~,~/":* _- ....,::*-.--I. -.. -.-..-.:,,,_,.~,/.'.;{:_ * .'::/~":. f '-:!;~_:.*~:.::.. *, <<LPCl/Contamment<<;::oolmgSystem,.dated February, 1994, Reference l l, * *. :*. ",::~_' :<<<~-7..?-.:,~~?r:.\\}~~.,.:; :**:: *_ -_... _*p~pvided a benc~ark '~alysis to validate the code" for application to.=... :._,..*. '. ' -.. _,, J~~~~1J~~~:{-_::_:j,; ).:Dre~":~~tio~~-f t~tY{:/~;-~_ ->:~j' ;:;,}::,*:~- '.<.-, '\\*co'*:* F*-, :;\\,;:.. - -

~,:~,~ "";:*~(-:_;~~Efi::i..~?-~i<2',:.~:.;'-i;:- ~~*~..:;;~,~, :-::* SHEX_\\ises:a *coupled reactor. pressure vessel' an~Lcontaimhent model,.. <<

... *.-... ::r--~~):}';,-::~p.*~~~:".:-"~':.-~!~--;:,~.;~:*..:c.. -.....,:.~.'*--.;..~--;:-,~.,:... r -1..l*

• _:..,___' __ J.,,_..-::. -

~ -*~- ",' - ~::;-;,:~~~~:0i~~~'.~i~*~~:-:s~:;k-~:.~*~~~~i~~~;~~e~:-o~.~<>d~l.~*~~~,s~~t~~-~ *NEB0-1_~3.2~,~~.'Th.e G~-~re .. ssure_, ~: ::_*~=:":~-.*~*....

. -~~~-:;.;~:-:}*~C:

1i~...,_;~:~_~r.~*~~;{~T:~'-l1TI'7), J::'.'~~~ppres~~on,Con~ent_ System An~yticru-.M()del,;_.-*date4 Mar<'.h,_197L:*.. <~*~.:>-*,. .-:<<~

• -.-*!~l:.r::...~---*..,.,~*

'-.r...r-*-,****-*.. (';~'j_;t-** ... ~ ** -....... ~;;..,~S,::o-:~~~~-

• -*-*:i:-:~d},8;;;.:..::::~~~::,.~:t":*': ".':.-and NED0-20533;.~~The:Generhl Electric**Mark III.Pressure Suppression*-.*:"*,>-.~~'-

-..,.*,,.-*=- -::::** ~..,.. -+-.;.... ;..:,,,,;.r '-!:" * - "f.: * ""~... ~ *

• .*.L r

"-.!~ ~. - -. ~'~r~'.\\~~~~~,~~:_p9tj:Wrinienf~Y.st~iriA!:ialyti9~.. ~,9<!eh.'dated ~une;*1_9/4,<<R~fer_en~e l_D.:.:... ~:- :-,.. ::,.. - ~~~~*~...,. e~:~~~~~~~~~~~?d.~1~~~ye_:~~~~i!J~§.~~r.~*x:~\\f~e~e~:~~-:c:wc:_uiat~~tiie.,,tt~fe_~1;::; i*;:.~:.::;~;;Ii:<~:~:*:, .. ~:,F _,..,,. ~1~~;.respqri~e,..~f. ~e.c~ritainmep(<lliritjg'.the,LO.CA:. iQri.s. ni9d¢1: peif orm_s..:flui<L~::~~~~~.;~: :~:=~~*.

ATTACHMENT A BACKGROUND AND SAFETY EVALUATION OF THE PROPOSED. CHANGES *

~. ..-,... ~- '. ATTACHMENT A: .**,'.. t*.

• _'.BACKGROirND AND SAFETY, EV -0,UATION OF THE PROPOSED CHANGES

• c **~ **: '

ATTACHMENT A '* L~ *' . '. *- ~_:**..

,<BACKGROUND AND SAFETY.EVALUATION OF THE PROPOSED CHANGES

. *_-1,*' .*, -~*

<)..

-~ATTACHMENT A .BACKGROUND AND SAFETY EVALUATION OF THE.PROPOSED CHANGES \\ ... (4)). .5.2.15 Minimu'm Containment Pressure - Short Term The short >.:.:.:.. *~_.'* * * :*.:.... :_**term.*(< 600 secs) minimum suppression chamber air space pressure as _a ... ::*~~~::-:~*:,~_-' */ ....*-\\, *.:. Jurict_io~,oftime is.calcula~ed using the model discussed in Section 5.2.10. . -'~.,._. _ "~. ~<.~,~*.,.'.:~,.->< *' :." :.The* s~enano iesulting ill the conditions that mimmized NPSH was .' :'-:*.~.->'..?_>:~//-'.*i~~:~.->~}:-':;*.*, _';:* *=.setected*(case'6a2: With 60%.thermal rnixfug) a5 descnbed in Reference*

• • '*;,;,~;~!f J'.J~:'t~l~~~~~#;~,~(l~),;}];J~;:b:n1:1n2~nJ~~;preSs~ri: See.~ecti~P 4:2:.i 6... * ***

Tj~llWll.li!tf 1~11J~f~~~~:~~~~~£~:~~:fi~a~~~1~~:r .:, ~.,:~;:; t~:.:~~;.~~,_;~.~-/:1,:;-1:_4/\\*'r-;--, }:,_: ~:~--:.(~:.: -=Branch.~Techiiical:Positioir* CSB 6"." 1-for applicability to the* system. design -..:.."'~ :~.',: 5:::.+/- ti:~}_-~f~~+/-~::~;~~~~~~-~:~:~ :'.-basis:1-~~3~st1tuti~n* efforts>:Tlie' anitlys~~ used. in.corrilld' s reconstitution~~ .. ~

• --1'!-'i~.,,.._

')<\\~.,_ ~-L ";.,-" -,.<o*.t:*~ ,..r 'h ~~ ~ '"* :J:

• -'.'.-:';~>~{~:~~\\::;~~*i..:.:~~~S7~,::::*;:~.~1"~-~-- ~,y:_~ffo~!t~" ey~!llltt:'.'NPSH ~e ~onseryative.as~umptions,which.niinirniz~. *

-.----~.,~,---.,<<**...,;;..~-.*,._ *. ".;.*:::;.,;*-:-;;.,"'-*""**-th:" :..:1 *~* 1 **' d--.*... -.... -.,. -. _,Th, "*: "d ~: :;.?~,-'t-'::~~-,o:-:-'2'r"t'::~.*-<:'5:0-.::-0.. ;,:;'::'.*.'. :*:_.;,7~*;~ e,ci:llcwate.. containment*pressute~ *, ese.assumptions provi e ari 1::' l'*r* *.,,.,,.., "'('.,<f. *., -,.. -.... ;:;-;;.<"";:.*~~!'.....;;,_..,~* .~*

• .> *_;.;.~~-s:;_;,,{~;~>:::::;;.~,::~:;,;.. {t'.:*0:~:,:~:~f>eqtii.valent.degiee otcbnseivatism-when.compared fo those listed in the. * :

~~->~:;::~~f~~7t~~*~~~E~~"f#h#f:i!-~~~~1~i~)~~~c:_1@-0$!atign Notice~~6:55"and Nilccon:~~nt $ystems_ Branch 6-* * * * ~.. ;.... ~ !\\ .. :t...:}L.ff~ *.,~..........c,.-.c T..::.-Y!:;.... ;:.-~~~,;;.*.;./,:*... ~~ *"'*... ~ ~=*;**-.,... "\\:.:,.,, ,:-,.~......... 'l

• -:..,'.,::;S:----~-:~*

~ 7 "t'.;;',i.::::::.:~ -}:.;:.;;;:_-:-;:-tmodel 1as!:)umpt1onsJor. a:PWR. The. assumptions* used to lllllllmize the ,_ ~:'. }-/t~~.i~~;--:~;:::2*t:1::- -~i~uµfiat :noli;co~den8able :-gru,*~coiiie~t ahd _th¢refore; rninilriize- ~onthlnnient\\ ""'**::i_. J-'"0;:,'i*::f~{\\._-.;-:i~-:--*-......;.:~.:;-.c:.:.r;;.r_ r; ri-... ~**-~--n*~'\\..:;. ~r. ~.:.. *~.. ~. '.*. "1*:* **

• =-

i --~*.;...:~*:;_*,~:~i->.,.

"":*~:;.;-"~*<,~:/~ ?f;.,~,:~"-~:.~_~S":'.:;t;-,,.:;:,...:,;:::pressur~.dw:mg*:~e J;;OC::A mclude the followmg_issues:

• ___ ".,-* -..
• _-_ -:...-.

__ ;~~~~~--f~~t~~~t~~;;~~~;~::~~t~;~{!:l~fJ;~~~~t'.~j~~~~~~::~7~~-'.~:~),':f/~~,~~t'>~.;:-.L:> ".*:_:*. 7

_*-~, ~.

,:.. :*:*

_-. :e-. "-... ~....,... _, _ _,,,"'**** _._.;....,.,", '*"... "'._:,,~ -**. *,"".~::,..Jmtifil-dty\\v.ell tepiperature of 150 <>.f. ... _. ~ *_;.-

• ,*\\'.,,, 'J;.,.
• .-,.i~(;;:*:-r.;-:~°!~o*:*i;

~

..:_~.. -*,*\\:;;/.;,-:..;*:\\'~r-.,1.--'I'~,.>- .J,T~;*... )~*).'7~ .:--,~*... ',' :* e *' '* "*.'\\. .;,.::*;J,ti<.;.-~*.z*3",;.*-.~ '<-:.*:.?'~.:.-~.,_.:>~~.. ~;.* _.'i:.:.~;:_-:~_Jmtuil:suppression.chamber temperature is set equal to maximum. *

• .\\,~ -:_, *.~*.;.. ;* :,*-i::;~-.;:...:....:.

~. ~... 1-.., J_-:- ],..,-..... ';'; ~'>;:... r:-.~; '* ~~.:- ~""!.... t\\..r-;~;~.\\.."' -.. < '....~-.. ' .~.. -*. ~ *~ ':. ~* -1'" -~ ..... '. '::/"

• Or :

_;:*."'-:.\\~:~;ifi~~::..=.::.~':.<'.~;~_~-:.~jI;;-.~~: :_;t-,. '~;*-:~,-~~;*i-:-'QP~t:~~g ~.:temperature _for me suppression_ po*ot.(95-r ). : __.... -:.: _ :..:.:. ~;-::.._-,.lk~*-:..........,~:.-_.,J;,.....,...'t~O._,,-J,<.*...:;......-*,.,,,..c.~

• • • -'-~.i_:.~-...,;J;.,~:--:,.~,.,~,l*.,..'-.."A;.C....

~,- ~I -;.-:~,,;*:-.-.... --*. -~,--.. :,1\\--~--_::~:-'~ -~*,~~,.;~.:-:;_:;_, ;~,~:.~~.:,.,:::::.E;:JriitiaJ.~rl..t.mrell -and wetwell -relative hUmidity. of 100% *'. -- -~ '.. --

• :;-/-~

t~:f~*r.-::.*.!-..:.X.;,_.. 1:-:-::.*.J:;;;: :......:-).'"~-::;.*:zJ,.,../::..,-v_:.'!--~*+/-:::~.~... /. r .. --;~*1*~:~..

• ,=~/~i.:.:~1'~:,,~i"*,~+/-F;:~.:J~':;*~;;§,;;;; ;~~f~1':~-;~~?1f:ImtiaLary~en;prissme\\set at miriimuin *expected. values* o!' 1. o *- *_ -.

~~~~~" ~~;~~~z~i~*~~~~:=~~~0.:::.:~Y;:t1;~~~;~;i~~?~~-f-~~£~i~:;?i1~{~~:-~--~-:~>~:*:.'.\\*=~~.i:.. c::.. -* -*::*: -*,-.:~:* -*: > ~- :-"~~* :-. *._ *: _*_ -. ~- *-*:*:*. -~:.*....,.. *-::.' \\ ::=* '::*;~::::,~~-~-',-_*~~.: :-:-:-*f;._*;;\\:*:.:=~*~::-;:*~;:.--,-;*,!'.":;::.~~~ -!~t~aI ~uppre.~swn pool volume,is at the lllllllmum operating val*ue.:-*

• *:.: _c~* ~1~.:~,,c;!Y/;_.. ;0*::,*.!:.:L.S*i~'::~,:;~;.,,~T}i.is'a5suniptibn_maxiriiizes the initial suppression chamber *air* volume,

-~* -.\\: ~ _-(-Sfi*

i~~g,~';~f;{

F~.

~~-~~95;~d ~~~~}~~_osp?~~~-:,J_OO~ ~~-20%: ; * *_--. _..,-,:_-~-*- ;_-*;*-*,-:_::.,.

~

;

~~

.

;:,:..\\,-*.-~ **-

~--~-.,, ~--

-~-;,.. ~~~rnO.%'-ijiixing

efficiency'oi :break:flow liquia with the drywell.-~:,:*..... **

~. *.. \\,... \\. . '~

• ATTACHMENT A'

. -BACKGROUND AND SAFETY EVALUATION OF THE PROPOSED CHANGES .containment.pr~-ss~e since prior to *containment spray initiation,. the break . -flowtemperature 'is 19wer than the drywell temperature;.

• . *... _20% mixing efficiency of break flow liquid with the diywell

~ *-. atmosphere after initiation of sprays. Using a reduced mixing efficiency

.. _,~.-- -,:_ :

• =<.::

.~-'.:

~after.imtiation *ofcontaininent

sprays minimizes ~ontaiJ1Illent pres.sure.. :. *

'.. "... /*

.sine~ ~eiemperanii:e ofthe break-flow liquid.following irut.iatioii of.,..

• ._:*::.:~->i::*'

_'.~:~.. ~:::

_;,,:.\\"::':.->_:.**~.. sprays is higher than tlie.dfyWell temperature.~_Prevfolis GE analyses have*

~~i,~iiii1":::~ii!~~::r~f ~I~~t~~~~~~i¥~~§i~**........ *

• :'~:*::::**-*. *:::.;';.. ::oi*:.~**.:;\\;,..,~,.. -:-;..*,,,,s,,,...: ~-:::best*matchestest data With respecttCf"dryWell pressure* Higher.values**** _.- * *.

~~*~~;=~

• ~:::...;;;:;::~;.;;,~{*:*_:;;..,<:.--.. : *. ;,:..~ ",-~:.. -~-~:-*. ~-" *:....... * 'For Cases la, 2a,'.2al **3a,'of Reference 4* 4a, 4al of-Reference 5*-' * * -

_;;i.~:_~.. ;.. ;i.:r~:~*~-*.,.L\\t°*"i.;\\~\\'.'.:;~~:~~:::.~-.~~-~--~;~*~:--;'-\\.*-~/~:_

~-~*~.. ~ ~ ,... ~*-*., *.*,*, --~:*:,_,::~;~".~:.:~:'.~-:~:'_~~,;o-'~.,:-~~~~":."::..:.;-.;:::,~.,;:~::, ;*5a;*,Sal,ofReference6;.and 6al.and 6a.2.ofRefetenceT9,-the maximum...,. ,, {.*.:*--,~.. ~-*~-...,'f

~* -~*-

~ *;-

~::.r..~*-=r..<~::--.'":lj *.

• I

_. ~." .=, *.. : 1 : _:;.. ;_:*_..2~0~--:~1'.. ~:* -;;,i-;-/,.~_\\f;;;."::"., *:;,~'.*t~ \\.;operating value of.the _dryWell temp~ratlir~ pf.15_0 *°F.and a relative :*. ; '*: -~.. '*.. * /. -:... -'"'-... ""~>4*.'"!".'!-.1'.r.:'***-**.... ~.,.. -f**t*;*~*.. r~~£:-:,...._**~ 1

• -*-~*"*-~--
• __ * *-.:~:,_<;~;':;t:;':"::._::.'_::c;*_;_, __ :;":,,:{.. :':.-"'f"~:-:::~humidity of 100%.. are used-to*mi.Iiimize.the* initial~non:-condensible gas..

~.-;-~~:~,~

<-:¢:.(:~~-r~:.. ~*r.... =-~.. :";".;::;;::~"-:.-::~~~.. :.ii.~::~."...:!.-~:-;_,

yJ*--*~-' ;;;.:.~* :. :*-... "*-~-*. ,l ...... ~.... ~ * ~"

~ :

. -~: *. ~ ""~~i'.I~~f *?;.~;;'f::*::*J'>~J:);::~;.;;*::~m~s-~~ m,~m!ll1ze.. th~*1?~g:te~-~~p.~ent,pres~ur~'-for th~.l'fP_S~ "_.. ;-, *.(/:.,_.

• • . ~* *.

,~J;,~., ,~t!~:~5J:$d}i~~f l~~f £~t~~~1~~~j;~~ic~::,;;:!'}f ;~7,~:;T,{'i?;:E,;_,@',:~; :": /~;~::~:~... * * *.*.*... . ~.,c:.;,_~;.;. :::,, ~-,.-,_-:.... >;c_-'.-~.. ~~ --:.'.: * -~.:.:;.;: ":'"-. _,.,.~-:-.:.,..,.,,,Eor <Zases la, 12a,,2al,-3a and 3al *of.Reference 4;.4a,;4al of * "'*,* -.1 ;c "* _,.'r~*t::;.. _~*..;::.... *~.:-.... *,.:...:.::._--;-r-~-~t:;.c.:.~* .,_!.!.................... ~-~~

• • • ~,:

~, ............. ~ ** *.-*,~-

• • ~*
  • -~*

.'.'.?:-.\\~::_..:. ;'}:.~ :~)'.':.. ;_:,. *>-::'--"~.'r:-~_'.:t?[.':J/... Reference,5_;*5a;:5.a1;:9fReference*6; and 6al -and 6a2 of Reference 19 the ,-",::*::;- ~.' ':>~~'.>'--~:--7-",-,,.-:_.,,;'-_ _.~_.::"~~:.~*:cf.~'.';~;.: fuitfal ~ell and*suppressi~li' 6hamber pressure" are at the mini~~.... " '.. -.. ~ -~~~~- ~.0~:1~*~.... ::1&,tr~~:~ -;:*.~:: ;~,:.. :*:,~:.! ~ ;; ** :i{.... * .'~~ *.. -~. '.-.*.. '.-..-- },..... " -* ;'... **~ '"i~

• • : -~. -~

':- ~ -~" ~, -

• '?.~.:::!. :::~*:.~- ~- ~' '.:**,,~.. :::-0,- -;;... :-'\\ -,~,/~.* *.; ""* expected :operatmg values to -nurum.1ze the.contamment pressure.~ ~, * ~, -* * ** * --

-~. * .1 -~Zf~~~~~:;+:(;~~:fR'~t~~~l~~~~iff~~~1~~1~~:i~~Jis~~2~~~~do~OF;; c. *.*.. *

• i:...,.:~;.:~-;~~;;;1'"~(:'):*_:~ ~~:-.-"A": :*;::z_~f,_~=o::-_:-~::jj~tf{-~ih"ifua \\vithbtt' ttiI~tiori~of he~t siilks, Heat sinks may increase '_*,.--.. *:, * * * * :_.

~~!J~~i~fi1;:~~Y~;S(.::Cf~YY~-)~~z:~~~~'JJ1~bt~:~~~ *~¥c;-~ear~~~~bs6~~ ~~ _porti~~* of the'.e~ergy ~ischarg~ci ~ __ :. -

• _,~ : -
• :-~?':Z~.2;;,t*]~:~~~-.:_-~ :~-. \\. :-:* ~~*. /~~-:-: ::~-'ff<?iil:ihe '.vessel,: thµ5 :rediicirig. suppression :pool temperature.-* Heat sinks

.,,,.;,_=~--~;*';' ::;;,._,.~:;;~~ _,_,.:. ::,-,~.. *.;!-f'"".;"~"":~:,,J1i~:refore heat siiiks are mc}uded,m t)l,e.moelel for. the loJ!g ierm: NPSH * -..., >.,.,,, -_-:;:..,, **..

, ATTACHMENT A. BACKGROUND AND SAFETY EVALUATION OF THE PROPOSED CHANGES ,

• Af>**considerations. *.(See Section 4.2.2).. The higher suppression chamber

.. air space pressure for this 5000 gpm condition results in a hig}i.NPSH

• .. _.available everi when coupled with the higher temperature (176°F)..

,:/~*.:J)ro e~s_ure that~no.long te~cavitation.occurs~ th~~ Core Spray and LPCI ._y.. :.:*: pumpsmust be throttled::--As mentioned in Se~tion.3 :3. l7, the.operators .**.. ' fr:;

• _.: **::. ~.. ;'have beentraitied to recogrii~e cavitation conditio;s*and protect theif

..., '.:~*: ;: :: ~; ~.-..

-

;... equipment.by: throttling flow ifevidence ofcavitation sho~ld occur..

<_.,_,;;;~~:::,<>.. '.*~*.< )_ :,*_:;:~"-;::., :*~, ~.... ~"~:.:\\.~*._::.~:;~,,~~;:._::~.,~-;>.. :*. *> '*;.:.. _*~,, ::_-.:,."_*: <,_. : ".,'._..

• -,..._~~... : ~.* :... ::._:_:.:,_,~. ~;~*.. :

__.~*'. *:::~<> ;;f~:Actlifil:ioiig tenrt'.~sH*margins are identi.fied.'in_.Section* 4:2.17.

i'~~8;r~cE~f ;. ;r

~~f f

~~~~~:cy:~;~t~it:~,!e::~r;~s;~on;~::ong;~~~sH: *. *

"'.*,:~~;.;~-.:,,\\*'-'**._.*;~.0 -_.~ '-::.:' :*.-:*:.- ~~..;;>-':*.:.:_c:".~:>-~":;~5.f.:18:.NPSHMargm -§ho,r_t TeI;m :.*The same ~sumpt1ons as m.. t~:w~~it:iJ[£~::;~t!;~:!t?I'~t~~?i~ 2~~~:i~!r1t::t:t.:i==::::~:1°:g th~ *.. * * * * **

;;-:*;_,:_ :_: *:*:;;:;>~:.* <-~--~-~~:r. ~-::"21'-Y* ~z*-=~ffi~ieqcy~of:br~fil(,flow)iquid\\vith -~en *atmosphere before initiation

,. '*,-,.,.... *r\\, "~** 1 !",...,.. i_*-...,. ~ ,.,.,,-~

~;c-- :_:~-.~l;~~-"~,,~.. ;;,,,,*~*,":~~ '-,* ;_ -'..--:~::-~?1: *fuS:Qf~spiay~( shorrterffij.'.:+/-fo*lowing';llie.irlltial *vessei ietiood, the break liquid

1~;,;~=~~;3:~~~tfft/5E,~:~~\\~;:;::~:~~-:}~ff~:;~~~J~:tfp#~!fyis~~f!~'~~~r-thaP,*~~~*:*-~l_l:*!~~pera~~: '.Therer~re; a

• .. : :.*-':~'.~:._.,7:.. ':,;~~.:- *.*:'-.: :< -:-.~ )*:~p....:~higherm1~g-~efficJency::m the.:sho~;;ten,n*reduces _the,~ell-... : *
• ~\\

~****:*... ;*.';.:-:..*. *;..:.. 4*;_:.:_,

• -**::..*-;:~""'.°";.!~'.1.J,.:'".'.72.*".:

,.....,j .*-~: -~ .1.* -:* ***,,._..... _.-.... ~

• < '., 1.:::/!~2/L'.~8¥~. -~. -~.. :; ::..~ :;: ~-<~

1

~-~5{ -*'.hteµtpe~ature,,-~eILpressure ind *siippr~ssion chamber pressw:e:,.This is *.

J' ***~~*-:'.5.

• ~--.:.... -~*\\*y; *:_~ i:'/-'~: *, _.: :_:'....--~:;~*~*,~:;i;{The,:CavitatiotfTest*Report 'discusseff iii: Section J.2:18 provides assurance

.**:~*::~\\~I~'.~;~31~t';,'::,~~~~~~t:f i~k~i~~:,~:it~~%;t~Y~J~;J*~~ur ~~out.drunage:

• . :~.:*<*-**_-'(':.*-}*;:;_-.. *:::,,..::,_*: ~:..:?.:i'.~--~~tiiaj,~P,o_cy,,~e_rm:~.SI:I margms.. are.sP:P'Yll'lil Section 4:2.18.

~.~1Jt~l~~~~i!~ 2 tf !f~jfifllflt~f~~~~ft1~IC:H~=nt

...' _ *. * ":.*,-,;,:.. *x-: ~: 'c-~*-:*~,:- -.-> ---.;~~* :'l:"~:~.:--:hcensmg'.bas1s.per-References*(l8) 1 "(21) --.(22) and.(23).: :*.,..,_.

)-_*;_::~::~:r;:2;-.~:,~~/:~i~~~ *---~~~~\\~~~~t~~:;~~§;c-~~~?:~=~~}~i~~~%t:;~;~{~.:tl~\\:~:.-:~:'.~.:::_;~.. :>:-:_."<-.* *.- * -- ,. * -~. :,,,,_*.:*- *. *. *.. -*:*:-. "... -"~; ~-.:""_':-'**~*J:::.-":l:;.,**:V;.. ~5.:2,20<Decqy,Heat Mode/.::. ANS 5:-1.--:.1979-.-.. Branch Technical -.~I~j~f j~t~!! 1Jil\\l!f i11!~!i11!~¥f i¥~1F;~~r. ~-.. *, :'* ~~;¥:~:~~---~ "-;./_. * ;'.; *::.--.-..J.- ;:_;..:";,.::~-¢{:.i:-ift.ote<l.).Il*4$J~\\9,;4~,th!f~ec~y.'"hear ge,i;iera~ort-._due,'~q tlJ.e hC?ayy ~lements U- *,

• ~~-

J...... ~- ** <...... .. _.,.... '......... --*--.;:;:::-;-, *..... *----') \\-'*.."~-- <.~ *** --.,.. -1 ... 't!!.. *t -<,.,-,......,.._... <: i:;:"/* if§f:'..~~~;)~:.-.1.~ /"'-~C<;;~--~5.~~"'t,.J.-;s.,,J.7?..9. :i~1id.:;Np;~39:,m~r~be;~~cUJate4.;a~~9.!~g:to~~e -e~pres~ions discussed

• '.~

~......

r*. ',/:...

• ~* --~..,. :... ~>>.'

~-~:..... :-. _.:..1 :- t.~.:.. ATTACHMENT A. ~

• • .BACKGROUND AND SAFETY EVALUATION OF THE PROPOSED Cfu.\\NGES.
• section 5.2:10 conditions (Heat Exchanger performance) of this report.

,.. The core heat includes decay. heat(ANS -S.1-1979), metal-water reaction. energy, fission power and fuel relaxation energy. A C()mparison of the * *

• • proposed dec~y heat model (ANS 5.1-1979) as-compared to the current J:)resden decay.heat model (May-Witt) is sho"(l below:*

i'*: Cooling Time(s): Comparison of ANS s:1-1979 vs. May-Witt

• .-~:: :"

~,..

• ):001.1n9 rfm_e(s>*~ secon,c:l~~*::§:.?--:-..c* * ~-:*...:-;-

~. '* ~...

• _/"*;~

I""_":;*,

• • .*,:*;*~,:-*-*,*

,-:*-".~~'-~.__:~*

.;.._--May-Witt *.

• . ~ :,. ~

.;..;A~S 5:1*. ..**.,.-;;;o>Y.: ~:..;*... :. 1*,,.,.. *":*'!".,. Although the ;o_NS. 5...1 197~ decay.heaf.nwdel.1s.more.re'.'11stlc.as * ::, ;..., *. *;....,....

• • ._;:::/_-,.:i'.i.~:;:;'c~~:~.\\.'.'~:::.~<~*~-.-'.~.. f.:*:.comparedt~*the*M~y~Witt*decay heat c~e, lhe results *are*$till

,*:~.' *--~_-r:_;.*/ *.:,*<<*.-.-*,'. * ~. <r:*~~*':.... ~... '." 1.. ...: -~:.... ~f :: * ~- ~.. -

• -~._.... ~..... s**~.
• 1,. *:

... ~.. . :~-~~~...

• ~-

.,._~--- ...'**i.

• • ~ *

~* * .I *

* ~

• • :~:-.*.

', :1:~:~.~;::!f1~~~:i~~::;~;:~f::~~~-~-}?:'~;:25 --f ~~d~~ter. fiow_jritq *the:vessel c6ntinue-s until aJ.fthe feedwater which _, "'$-'"'.*>*-.... ~ ~~--.. ".., ** *...-- I ~-- :: 0 --~~'.;:;t+~:~,jJ~;;;?.;-:;-:~l~.Jzf '.:~*<<< ~;",:wiJI:incre;ise* _the _suppression*p*ool_ temperat_lite 'is': injected *into*~e vesse~.

7

,...;,:,...q,t *...,,,.!..:...,i-.. ;;,i.;;~~-*-;:i*.. < ..... :~~--......;::{' *~2~~.~;::.. :.. -*.:...... ;1... adi~. * - : * * * --- * * .~. * *ai- -...... 1. * * : fth *--- *

• • th**c. d
• -*.i -

~-<~~-.: 7 .~~"f¥?.i:--:~~&'~~;;J.:;.:. ~"'*;'.';;/.*:,; ~;~),_:;;_ ;*~*' n ~ ti on,'. a conse:ryat,ve <'. cw~t101)..o. e en~rgy 11?-. e *,i,ee water.:;::.. -<*.:'_::**.*.-::-~ ___ ;.

• .:***.::..:.::.... :_...,..,:._,-/:,*-~*=::.~;,..,I...... :,....,~: ~1:,::1.;.;....1~.:*-**"':-'*,..._~*.... ""-:-""':.. *
• ~

':\\. - '}* ~.~.,,.-.. __:;..*~~'°":,::;:,.. ~,:*'i'.',°t:.*~~.::::~-,~~.-:~c.'.-::,_.-:,:.~.;;,:p1pmg1s added-to.the~RPV/contamment system.. :::.. ':'.* *.. :. : ~... ""-*.,__.. -,.

ATTACHMENT A.

• BACKGROUND.AND.SAFETY EVALUATION OF THE PROPOSED CHANGES

... ' ~.. ATTACHMENT.A

BACKGROUND AND SAFETY EVALUATION OF THE *PROPOSED CHANGES 5.2.21

., _... : ~ '

.:\\ ATTACHMENT A.. .. BACKGROUND AND SAFETY EVALUATION OF THE PROPOSED CHANGES .Table 5.1: COMPARISON OF CURRENT VS. PROPOSED OPERATING PARAMETERS

• PARAMETER DESCRIPTION
  • ~.-.~;..
• 5.2.1 Assumed Limiting Accident 5.22 LPCl/CCSW Af>
• 5.2.3 CCSW Subsysti:~ Flow - Nominal *

.5:2:4 ECCS.Flow - Gore Spray*(CS) -

• .~,~;,.*:.*.

~

~ CURRENT PARAMETER Large Break LOCA

• \\
• 2()_psid

7000 gpm, 560Q gpm to maintain

• * : LPCl/CCSW pressure differential

.* 5276 gpm forfirst 200 ~econds* . 4500 gpm after2PO seconds.: 5000 gpm * .~. Not explicitely accounted Jot, ..~

• 98:6 x 10 Btu/hr @ 10, 700 LPCI flow

. and 7000 gpmCCSW flow** .'.... *..-.'*~:'~~{~.':-:.. :.">'.,,.":;:,*.:::*-~.~.;, -.: :*5.2:8 Maximum Service' Water Inlet * *** .75.*. -~ ~*./ . *,:r; . ~ "'.

• ,_

  '--!~~~::~. :~

PROPOSED PARAMETER Large Break LOCA 20 psid. . 5000 gpm for heat rem.oval 5650 gpm for first 200 seconds

• .* 4500 gpm after 200 seconds.

Not accounted for. 71 x 10 B.tu/hr @ 5000 gpm LPCI flow and 5000_gpm CCSW flow * * *

• 95 for 1'/P~H. when.coupled with cniinimum containment pressure; 176

."F for other purposes .See Section.5.3.J 1 -.. -..

• • .:~~~,..*,,-..Y+i :~~-i.'1\\- '.5!2J2.Maximum Containment Pressure'-...,.10-1l;psig@600 seconds; 8 psig *

'16.~ psig' at 600*s_econds *

• ~--

--~~~ts~~;!t~~z!- --L~ng Tenn -~>.600 seco~dsf~.".',~~,.~- *:.:.::**:;_: s~o~.d peak c~ : 1 _< ~ _ -. *i* :*. *,-; . "'*.".-.,:,,-:_*~:-;-'~>>:;;*t_;'.!;.:.*.;~"-: ** --*.,',

• 5.2.;13-Maxtmum Co_ntainment Pressu.re:~ *.; :- -48 ps1g. -:,*.* ~<.. ~
• <\\f ~i~~f~f~ ;;~~r~;~;~~~i~81\\~ 6~{*:,* ~:*:*:..

.. :..,,.* ~-,~~0r*:~.. ".-::::1::;,.'",-:{.,.;:~~':J!.; 5,2.*l ~.Mm1mum ~ontainment Pressure~: " *not-addressed" '

:.. :.'. s;r?,:~ v~/!:~::

i*;;~~~~\\.. :~1~~~ ~Short Terln.:t ~::~i~{i~~:~d!:: **~:. _:t.:~~ ~~.. *~~~~:\\:-: ~-;

4

• "* *;r~. *

~ ~: ;~ ~}'~:i-~~¥;5_.,2' -~~~~~-'-';f)'_i;~:.:s.p 6 Crt:!fite~ ContD:inment _Overiiressurizatipn,;. : 2 psig _in short term,:O psig !ong tenn _ _,,

• .-~~=J~(l

.~.. -} 2.9 psig.- 'NPSH Considerations; -.*

wh*en coupled withmax*tempenitu~'=

• 1'.7 psig

c

. V).:psig. * '* *.;

• ~**.. ""*

~. :-": -.. ~ .~1~; ,..i**. ..SeeFig_ure 4})6.. ~~':..~. :..- 5.8 feet (New strainers:will be.,. -iower) -'*. :.>--: '.:'*,.-.,** -.,,:_ ANS s:t-1979 methodology. . *.,*.. ; *-*.- ;-*. _;..: -:......::**.. **--~ .: *-~. . *... /

-~**' *. ATTACHMENTA* BACKGROUND AND SAFETY EVALUATION OF THE PROPOSED CHANGES '5.3 Comparison to SRP Critena 5.3.1

• Single Failure -Analyses ofthe consequences of single.

.... :comp~nent malfunctions. None of the proposed changes a5sociated with

• ~ * '.

0

• the design ba5is reconstitution efforts affects the redundancy of the CHRS.

0

• • . _-i;.'. *:.' ~ __ * *Two ~epru:ate and, independent LPC! ~containinent cooling subsy~tems are

~;.)*::"'~-:**.. :.'* ::**.*. :. *~<.*._*\\provided to remove heat from_ the containment, reduce:containment ,. ::~--~\\\\* ?-:~:~/~~::).;_~~.---1.;pre~sille ~d resto!e suppressiori_pool.temperature following a postulated .. * *.. * *...,..:~:.. :,.*,:f.. :,<"?~>~:;',\\LOCA~-..*Each contairurient.cooling* subsystem consists of two (2) LPCI.' *

• ~**(i~,...,... ;;..,:.-:
• ~:..

.~.-.,. ;,,;.-:.. *;:.. -. ;:.. -... ~~ *:*. ~. ~ >>-... ;_ -:* *..,-~.~*:,.: _..,":... r.:./':\\: :,.. ;::. *..';plµllps,_oile coritainmentco_oling*heat exchanger, one drywell l)pray, *.

• .:{5):.:y y2~+t:\\:}~~--.:fi~-~::G:]~:f~*~<>_header.,*.~~-~ ~~pai:ate.~pra~_linetern~i~atin~ at a common suppres.sio~.-

--.*:::~~.:~~*;~';;-'*'.~/.::*:~;;*:;:,:_ -,~;

_,;.;.*.:+Y':*.t~~:: :chambernng header,..Coohng water is prov1d.ed by.two (2) *contmnment'.... . :~}(.\\~_,:-~:J;_:4;~~t'::*::~"2/~.-::;:':~t~~~:i;;1.:.:}JC6ol41g Service Water (C~SW)'punips jn each containment cooling. -:. **. *. ':::*... ~~ ~-.. :c~'+,:~'.: ~~~?~t!):::*~*',:***{~~,;:;?\\~'subsystem. *.the contallullenf cooling subsystem utilizes the same major** :. 'r'('.-*,..,;;;'2'."*i.;-r---:.~ *.i........,:... -*:.';:.>*-:. ~ ::;_:;;.;.:*--*

• .:.~~.~~:* ~: :0:'j-__-~:;:.~*:'.~,::l~... "f.S~-~-;:~~~;~'i-).~,?~"- :comp~n_en~~-~-the LP~I.sub~ystem,.p~us additional_piping and valves to. * *:.*..
• . *_/;:.<.i.;_;~ * ;:*:._.. '~~.. -. ~-:(\\~_:/?::~:. :_-r-~.. :'direc! coo.ling* ~atei to' the'containment. Each subsystem *is capable of *

~~>_.,:::-.*,:;_:~::.-~.. ~-~s;.~;*~;:.,,:~~;~~~ ~~::;.;::.. ~,_-*'*removirig decay. neat and'-the eriergy °from any credible metal-water ~ ::::- ~ -i:-, : .,,.,., r: * *, ;"I..- ~ '-~... '. -if...... t'""

-

~* *... '

~ ~

• '*.. ~-~":* \\. :.::. F:;.:.*'~' "'..:,._., :.:,:.C'~~.. *:-~"/;**-<-".!:.reaction af a rate which 'Will prevent containment presslires and i,._ ~....

-~ i, _:;.:~.* ::~.-.:, ~.::* *):*~_;_):::~:\\)"-:~(,t_!:~.'*'~(;~~,.*~-~tempe~atures::fr,~iji *exc~eciiO:g their. design *values °{see UFSARSection. * ~/:~y~~~~~:~~f {*n~1~1~~:::~;~;~~~;I:lL~- <rf ;J*t '7> {-; : * *., * * --, -.* * * ** ~ -* *.. ** )', -

.-;--., :- *L::.::~,~:,:..;.,;;<'~..{::f:°:.:~:\\*:.Vanous* ~ys~em~ mte:r:act1ons and 'f~lure.*modes of the LPCIIC9SW

!:::::-... :/'-~ 1-">::_.'"'\\:*::-c:~;_:J;~-_::~!:;;:J:~-z=:->sy~tem:as rel~ted.tc)contairunent coolmg-have'been identified and.*,.. '*".*.. ;.*. ; _,.;,_._:.;~~. *~*;~*\\:~::-~*~:-~.*-rr*f:'r':-;~:/~;.:,:~..'*\\r'.~':-; 1 .*~"....... : * -*.'1..

• .':~.,~.; '..~-,.,~"'~.:=."*; ;::::":*-'*:=;;:,.;,i "-~~\\/~":~:evaluated as documented m the"UFSAR.:* They are unchanged by*this

~ -. r-::-==~--:-....,,----'-:---:--~---..,...------'l'------..,..,....----..;....."'----------'-....,-.-'----..... . (. *- * :;-:- ' ':.

• UFSAR *
• 6~2.2.2.... :....,.

~. -. ~: -: ' .- :; *\\ . ~-:.--"::.... --:.* '.

• ~. *..... '*

9.2.'l---.. ~. __.

.ATTACHMENT A .... '*:**. BACKGROUND AND SAFETY EVALUATION OF THE PROPOSED CHANGES .Notes: *

• ~
• (1)

See Section 5.3.11.of tliis amendment for a discussion of EQ of the

• . CHRS

. '(2) . Se~ s'ection 5:5.2 of this am~ndment (Motor Bearmg*Cooling Water T~mperature) ** - .*.. (3) . *.See* Section 5. 5.1 of this amendment (ElectricaI Loading).

• (4)
• See* Section.5.3.2 of.this ~endnient (Availa1'ie NPSH.to.CHRS)

(5).

Se~.Section.5.5:3 o{thisamendment' (Torus Attached Piping.:*.*** . *. *** ~.. ~Tem~er~tiir~si'.* * *,::.'.* *_,:.. *.. _*. <-~**:.*. *.. " -.~; * ** ..... *~;:.~ -.~

,~*--'"'."

.:.,.~

,':_:*.. -,,.._.. *_.. ~--** . ~.. " ~.... :.-....

• -~-.......

)~ rj,~>;~:.c:.:._:.;0;~<*t:::i;:i;}~>~-

7 -:'** ;'.:.. : Vari.O!!S_pump combinations wer~~reviewed to deteriiifue\\vhether or riot-.*.. '.~'. :*. _. _-.';.- *,~::;.~~~t!~!~~-~;;:;;~. ?,:'.*~.. :.=~~~;:-':~.:~*:.. :~\\adequate NPSH *was.'available*. ::The puinp~c.~mh~ations. are identified m : '. ~.. -.

• ~..
• ,';:*:i*::;~,.,.*~*.:;.. \\"':.:'..:.~l;:,2,':'.*:':":::"": :. '::.::.:-"c*.~ ~S... *

,. **4* 2 17*

• d"4**2 **18 'f*thi"' ** '* **.elm* * : .:.:_*., :'..,..>... :.*: * * * * *,;
• -**. -*.. **<<*~;,.:,..,....,,,<<... ~:...-: *;~,... ~ ;.~ -;.. -,

.e<;t1o~s._....an o. ~amen ent._.. 7 >-..*.~~j:,~:-~~.~~3?1~~f~;e:~~~E:-~~~~;~;*~:>~:}*~~f:*~~~;:~.<::~!:*~'"?"*'.:{-*. ~-.. -~:, 1?:*., \\. _.i. ~>,,<*.. ~.;:--;;~ o <..-. -~ ;'f:_-:--.~:=~'/~:_?:;';_ \\:= ~*:.::'. -_*:. *_.:--.: ~ *-*:... ** -.~.; , 7;~:.~... ~~~:.~~\\~.~~'.<~~,;:.:~:;~())::*~*'}Jnteractfo_~*be~e~n ~e,LP¢fand co'i-~ spr~y sucti'on pipfug i~ ad~essed iii. *- *~* -~*.. * .:-~-... ~.---... t.... -...* ~_':"""-l"f*"'.".*i*;'I............... _ _,._

• .:******-.~

.~*

• • 1*."""..

,...,.-~

,s.--,::.:r-£'-"-:.'"*':::.~ *-*

~*"* *.-::~,,*:** '"°""*?thffNPSH:caJ.cufations'sho:Wn in Sectfons4 2 17 and 4 '2 18 of this:* * '* *,. ,:~:if li\\ill~~,;,5f }f!~J~K~~;!~(&~~lS~i~~§~~~~Sd~i~d... *;. *.* *'* . :;1;~~~;_}~}-;~:;: '..:,;.~/~(*;';'.~"'~~~:. '~f:* ~: *J: :'*:accommodate* a sirigle**active~failure.. ~The Dre.sden *CHRS is capable of * -~~.,.,:::;:-!~... *~~-t:.~.[-t::~=""\\;:.~~;* *: ~*. _* './' ~ ""***~ *. ... *:..... :.. ~¥*.-~:. -~.-... ** ~ . \\ *-.... "' .. -~* - *,. ~* *' . ~*--.:.

• • .. ~.'

.:..:*. -.~.-:71---:::J;id:~;;*_-..;~ ~if':;~,c. --:**:;-~:: :".. ~* ::--?~*: *:;w.1thstan41I!g a ~mgle.f~Ilurt:'. -~tliout.tqss.of_funct1on.. _ Therefore, ComEd -**.-. *. -t ..... l..... ~. 4*<>-"'l*-*-**-~-. *~~-- "\\..... ~-.... *.,,,,_ ~ --~-

• -*~

.~ -:~ :*~.;&~~*,:::*::<,~ti~~;~~*,;:;~~~t1f':..,~~-*... -:: : -- :. *. :.J.\\has *concluded:that Dresden-Station satisfies tlie *single failure criteria'.- *... f"~'tW~!F~:"'~t?H<f\\,~~ii~~i~~ 0*,~~~~~~~r~~s< s;**:'i~}. * ,_..:-*~,- Z.-.::***"-j;:::-~:-:.'.**...,'° ~:.*... :.. "**.,.:1":-:-._r.,;" *,.~

• 532*. Available NPSH to.ECCS*.- Analyses' of the available net L~;,~111~~~t".'f +{,{~"~t~f JJ~~~t~1ii~~~~~;$:~1;:~. ***.*..

?.:.~.;;;,0,::-:*.c;,,.. *.'-;::,.:i:;~. i.*,:~::.::,'..*.. '-~* ~; ";'<.. ~_:??.:** :~( ~6QO seccn1ds) : an<;l long-.term (~ 600 seconds) is, discussed *m Sections ;,......... _,.

ATTACHMENT A BACKGROUND AND SAFETYEVALUATION OF THE PROPOSED CHANGES pressure conditions. Based on that analysis, ComEd has concluded that -Dresden Station satisfies the. NPSH criteria specified for the CHRS in . NUREG-0800. 5.3.3. 'Heat Removal 'Capab,ility of Spray System - Analyses of the heat removal capability of the spray water system.. The LPCI Heat. Exchanger~performance was conservatively evaluated as discussed in. *. .S~ction 52.7. The analysis ofcontaininent pres~ure and-temperature * .,.. -. *" response 'cori~ed additfonal.. co~seivatism ru;' discussed in.Seetion S.2.10. ,~ -: '"".~>Ba!ied upon.the evaluations presented'in:Sections~5.2.7*~d 5.2.lO, ComEd.

~*~.>*~ :->*: ;. ' ". ', ~ ~ ::.. :: has"<:lemopstrated that the heat removal capabilility of the spray' system is

-.:~~--;. *:*. ':_*-_.... '.a:cc*eptable*:::_~.. **-:.. .~-.. -.. *.. *.* .... *-'::c~??~~;;~:~*.~.-_, >-

• . *

  ~. *-:~:3~.. :~-~~~:~~~~o:~~--c~;~bilitY:-~iFan-~~o-ler He~t Exchangers~**

• _.. *~::/ 5** >f-" ~-;

~-':.:*-... *.: * :-. *-.: -. Artajyses. of the~ heat remov~L capability of fan cooler heat _exchangers -

I

• ~ :; <: -*. * -.

~:. -.. ::_.. - * ~... *:* * >}The' Dresderi equivalentto _the* fan cooler$ mentioned in NUREG-0800 are .* -_.:;.. ~ \\:. _,. _:**.1>.: ': -~"<2; ::;:* ~:: :;';~ ":*.:.:~~the.D~d(Coolers'. :.The-:D_~e.H -Goofors ;operate_;c~ntiimously 'dUring --. .. -~.. -.. _

• _ ;:*<?": :>-* *~\\'?ff: :::i:i6hriai-operatioJ;.*to*'infilntainiilie.~equn'.ed drywell operating-temp~ratilres.'

._..-: * :.::~ ~~ <* -..- ' --., :-, '.._::" ~-:~':*;_:*;.~The.D~~ll.C~qle~s trip ~n *a* LOCA--_siglial. Therefore,-rio credit is taken .. ;.,;~~,-~::;;.,.___,_ >::_~::~-~~d:the*r~q4irem_e~~ qf~G-(l800 are:*not relevant regarding.the.heat .', ; 5r',L *: :'.'..-.,*,,:*~::~~~J~~~~~X;~,~0~~~~l; 0 ~(~;, 1 $f ~:r 0 v~~Y*~~..

• . :.. --- : ~-;. __

~ *" >- .... _....-.,~: ~~":::.:~s<S-.3,?.~_;P_otential'for'Swface Fowing and its Effects-*-The potential ,..,-.,:... -*,- :*fo~_:sWfaceJouiing.of fan.cpolei:;*r~ch-~ufatio~, and.containrllent cooling >~:.)e~.1.ce)y_~te_~:eXchangers',;~d-the effeCi:on.heat-t~xchanger perforinance. .....,, *~.; __ - * - * .. _'_;_,~- -:~.. /' ::,(:~J'hj:de~igi} ~~is*~-:~P*O~. HeafExclianger heatremoval rate: is based.on a - - -~-.

'-~:-~~f;;~~sheil :~icie'"C(deriilllefaliZed*waterj foµimgfac~Of of 0.0005.arid'a tUbe' side

_, -~:-.~..

"; *:';'- -. :*:.*:z.. :_:::l(ii;verw~teHI<?wuigJaCior.ofO.oQ2;*":Th~s~ vajtiescar~ consistent With the

• . __ '*::. ~:_:.::~!~~_,;::Y\\tjil}tii~i£i6hajigerJv1ap.uf~chirei~';A:~socia~i~n (TEMA) guidance for the
• . :-~~-:-~,~~.--r~--~*-:;~:C 1

'.'~':1ieat~x~li~gei~ c)petati_~g~:W14e~~coriditions*similar.io:the LPCI heat * - -. _ ".*; ;.-:.:**:~*7;.t.:-.}L\\eX~hfil.igef: ~~-s~*sho\\\\ln on -the plant systein _heat.exchanger data sheet, the .-. -_ >:.V.. s~ell ~ide desi_~_veloCity~ls:5.Q_ft/sec-ai1~,~00-gp1:11 and the. tube side -~ _,.._ --_- ~---*:_ "-~~:-,aesigtl ~efoc_it)r-i~*5_. fft!se.c at.7000 gpm".

• Con5idering a plimp_ _

'.;_. _':~~::~:-"~,,:,~~.<- :_ ~.-.*.:*,-- *;: : __ ;*~~~;::~:_:-~-'.i{ctjinpm~ti~~16(~~~-;(lJ/L.P:c;(J>~iJ-:~d*~9:Frcc~v;.P~P withsooo. :*

."* * *.~:,.,-_ "*<. **.. ***

,.. *,~-.;:.~~ ::.','gpm,onthe.. s}\\ell side and Wi,th;5000-gpm oii the tube side, these veIOcities

• , '* ':. *~"'-"*' ~ ~.. ~

• T

' : ~..

-

:* *.-**.f*. :- ', *,_

")~:;.*:!:.*:,_.,:*,:** *,,_*. A>.*.,.*:, t.: '**,, '*~-.*..,,.~* :~. -..:-.-- ~-:*'*'U;:~.:::,\\:- 0

h, :.*.. -.: -. :.:.': :.,- -~--:-;;

_:-.~'.l?'/tjia:nge~t9~~;.34*;ft/~ec on-:the shell side*and. 4.07 ft/sec on the tube side.. As. ~;~~~;~ Ji-~.,_{ 2~0~~:-~-. .;~_.~:.-;;. * :-:: : -~.~.-. :~.':':.':l')~ ~.z;:;Ph~~sh~U :side ~water i$.suppr~~sion pool/reactor water* ciicUlated *by the

• e... *--"i:C 1:,.t:~7*~.!..!.,.. <'ll"....... ~ *.,.!:.q~""'* *-::;-;*.*').*......,-.... ~!.;;'""'1'-fi:::-:..c:"'~--

r/:-fr~... ;"°'" -~~::"-:_.-... -,,......,,-~*""~"":"":-.,,*:CA,*.:.., *, *.."1.;.J'!:.*. _..,,,.. --.;?

• ~

l*~{:~"~~==~:::~'\\.:::c~\\ *.- \\. ~*;;~-~:;:~,;~~,:..~~:-0,J;f P,GI"i?iimp-s::;;;The;fube'_side"'waier:'is-'iiver"water. m_ a* orice through-cyde,-.. :.-:*:,... - .. -."**i*~-

---

¢.l.:-!L.::._..,,

_,,,~.;.~... 'lt~;...,.-r-;=*Ji"-;;.. *-;:,..,-uiJ,.o-..... ~.. -r*-*

~.

..:"*"".. * *--*1..:;_...

_;-<>,.3'.::!:.i..--==_.-.. _

• ~ *-;*=

.~:i

~

• 's~;:;;~z?:';,:* ~?~-~-::-~~,,---- *-*-

r.'::'@.Y£~JJiy~tlie~cc~.~-ii~Psf.ml!~iQ:9.09~,fohl~gfa£~or -~~-~~_risi_st~~~.~th -. -*:..

\\* -*.* ~.. ATTACHMENT A

• *.~

~ ~ BACKGROUND AND SAFETY EVALUATION OF THE PROPOSED CHANGES

• _ TEMA guidance for.condensate in a* closed cycie at all water.veloCities.

The 0.002 fouling factor is consistent with !EMA "guidance for muddy or .. - silty water conditions at a velocity of greater than 3.0 ft/sec. *

• ,\\ "'

Tube and shell*side fouling factors are maintained beJow*design-values by

~-. *.a* program of insp~ction and_ Cleaning during planned*plant refueling * *:

-outages. * ... The* containment cooling s~rvi~e \\Vater"is treatedwith:biocide ~o control .~::.,,;: O'I . microfolliirig and ~lam shell macrofouling.,The LP¢lheat e~changer is a

• -~,--- ~:-;_:.~;-~'_? )... *: :. -__

.. wertical heat exchanger~ Therefore, the~silt will not tend to settle:in the*

• ., *_.*.. ~*;;_.. *:*(\\.'(1J.~~:'"~;:.",_~.:.. ~"- ~~_\\!->. *heat exch~ge~ tubes. Operabilify tests for ECCS require tl)at water.be nin

".**.,..*.:._.,..~-b.),*(;.*.~;.,.-:......* - . " _..... :\\;,,,**:-~_;,~_-",'-_--:".:.'.')>_>_,, -~ *.'.' _.** _:*. !hrough the heat_exchanger periodically during_plant operati.on.. This.. * -* ~"*~: -~*... :;. :~.-*~*1:.. F>:-*::./~.~{~-:_. __ . *_prevents long period~ of stagnation fr9m occurrillg. Tues~ design and.:.

• i~~£~~;~w~~f ~$~~.~c<

0 ;71'.°:~g.factors will mininllZ£ ~e poten~aifor fouJ.ing;.

• --~ :., ::-~-> \\'.:C~,~:.-.. j ;'*!:~:**~- *:":'.*'.*'. "/*~*-' * * *Therefore; ComEd has conduded that Dresden Station satisfies the* surface* -: *.. :., *
• ~--:'->':~~'*Y.V?'i~+*-.~ri:..:_::;:.:_*.?,:.;*-*:_.*

fi l".... :*. " 'fi a* fi.:th. CHR.. S"... NURE--- ... G"0-800.. *:.. "'. -:.--_ . - '-.*;**< :*..:-*--'"'-' 7'f-.*:*i*;;,*>:::-. :, :': _

• . ou ing -cntena speci e or e _ _. in

• .,_... :.....-:,
• _. :;o

-~~~~-.. ~2~~-.:~

• :.:.':;;:._,.:.,,*'-::~<'>?*:::*:~:;.*. ~ :!,*',:;".. penodic mservice mspection and operabi_hty test1:11g _of each system or *.:..... _._....,,,_.... ::,

~.

.::.~_;::+:~~~:~~i~_:::-.:>-C:;.. ~.--"-~"'". -,*component These s_ystems* are part of the station ap.provedISI Progr' am:>:. :.,. ::-..*_..

,_,.~..,-.--,~ .. t;_,.: - >: ~ , *._,,. :*\\*_::f;~:-,-;:':~:*Y:;:~'.'t *~*:.:: ::*~.::-:*:- *:eeriodic testing o(CC~~,"LPCI, and Coie Spray system pumps-and..... _. .... : *j,::i.':J.~.. ;~:f~T{.~;;:r:>O:. :.< ~:i:

. selected -valves *is perfo~ed~t.o :demonstrate. system operabilitY_:. Pillnp~:* _*> ;~~ *. :, :_:.

~~/?:':_!:~)'./'~~--~~:_;;~::~:: '.~::'~*:*::. ~.. :-.::..... testing includes :demonstrating delivery of rated flo:w at.a spec;ific.pressure; :_......

.-*.:_t<:::*),;,(f:D~~:";7~:::~::.-*.~

• Piping and heat exchangei"infestation by Corbicula (Asiatic dams) has * * * ~. *...

~*....,.--.... ~.:£-:.*-.--:-.*~"'.. '~*.-~.... ;~-:"t':ic*-:,":~\\~;~.,.~ :,:-..\\.\\

,.:~~: :/;<..';.:.\\~~?(\\:i:I:{;.;* ('..:.:. '..;~ :... been identified as a problem to the Dresden.safety-related.seI"Vice. water _. *:-.

• ~*.c,\\;l~1~1~i*~~f

~i2t.:.'~s1e;;ie!1::~ 0 l~:';:~~~d::*,:t:s:~~!~i:r;::*~~~~r~.. * '.** **** * -~, _*i.; ~*_,:{-/ :~e:::~:~*:;:~::;:~;.;*:*:;.~':.:::r ~--' :* ~~occur ill safety:.'related systems.Using river watei:**the program includes:...

":_ **--.?.~*-:,_/~? :_:::-,.-;.-~~:~:::.. :.-. -:...... - -_ Periodic. inspection* and"cle.aning of the intitlce.bays;,Perlodic:biocide* _:. -_,

• ~_:*': ~: ',:;::;::*/~;&~';:,\\;'//?'}:/~':::.:~: _,, ::*.
• mjection into the:iiitake\\bay or service w;iter distributjon:header;*PetfodiC.*.. *

""</\\:-_*::;:,,~..,:<:' *, ;', :*~*'....... *. "flushing o,f.infrequentiy uSed or stagnant li11.es in safety-related service. : - . '. >-~~":0;.*.";.,~::>*L,~".\\':~~:=~-. ~.:. __,. -~ater systems; Annuru water and substrate sampling; Periddic testing,-,'.

~~~};~f Z!~~~~t3~

*~~~, *. _:;:~~;:~~~.:~~~:i:~:~;~;\\:fe~;~:~::c!~~t~. * **_*.... :

.::~",;?:+'0~::::., *.<f.:,*:.~**:?iJ.T i-""*: r*:c;... *, erosion, siltmg,. ~Cl..biofotilmg.,_. These.mspect10n.and testmg programs are. *........ _. .. ; **~

~.-.. T* j . ATTACHMENT A

• .BACKGROUND AND SAFETY EVALUATION OF THE PROPOSED.CHANGES

. ; r. ~eriiains at equal to greater than 20 psid at greater than or equal *sooo gpm.. flow rates for both LPCI and CCSW appropriate ISTacceptance limits \\lave been established (see Reference (3)). *Therefore, Com.Ed has... ., :. *::<. _- *.. :~... ~ __ ~o~Cluded that satisfies the*ISl/IST criteri~ specified in NUREG-0800. .,{_:' ~.*>*:*~~~-*~c~:*,_ ~-:::.-'::/.\\<:.. -,:*~~:- *:_*.. --~. :~-..

• i-~S.3.7.Debris Effect~~* S~reen Blockage and Pump Seal Failtire *-

-"~}.~(-~~J~t~-.-:::'~:::*. :.::::<,::-:;*:":*The 'design ()f sump~* and \\Yater sources*f~!:emergericy core cooling and'.

• i,.,,* ~;~:.:.< d::.. ~-~:.. ;:rr *;~,.;.... :~.=::\\->:._\\containment spr~}'. systems, including an ~sessment for potential 19ss of"- * *.

_; ;°';:;-:~-~i;X~:;~_~._':~>0 ~~ .:.:.~:_::~-.. <<;tong-term cooling capa~ility due to LOCA generated debris effects such as. . -.*~:.,*X.~:~~~::.-!::::~~t::.~i:;.. ;.;.~~::_:i" _:-:**debris screen blockage and pump seal ffillure."-The current design basis for.-'.-'-*...

-;~:~t~'.;.~~)t5::~/_:'_~:::;.,~\\:t~~:*:-~~~*-.::~(- /.:~the. d~sign ~f-sillnps and.water sources-or:tl_ie ECCS and co~tainment spray.-.

.'~~~*'t:,;.;,!4;},,.-_*;_,',--::,L~'.,.*(-""'*'-*~'-~'._,F*-..'<*t--*~

• (<,

,':'.i.*' .. *;_..,,,_.*,*:*~_.~~:;,::.,.-~;::_-~,? y,,~*--..~-.,.;_,\\'.-:"_/ *syste*J;11S-1s prov1ded_-mUFSAR Sectl~n 6.2.~.3_.2. The:affected.UFSAR.-. -

• ~- _--:l~.~/~.~~:i::::t>>:, ~>;.}: ~- **':::: '*.'..::;,.*~,.::.. C.::'.:'.:~edipns.have been.revis~d-t~ re.fleet 'the reconsti~t~d strainefhead 'loss as __

.~,;,;:'.,;f '.S~~~~,~l~f~~:-~:~*:,i\\\\::'.~:'.-: '.".-.~-,;-o: :d~scribe_d in-Re'rerenc~s-(1'8), (21);(22):and.(23)..(<, *_, :...,.. * .. ~-::':(8-ftf~f¥,~~r:~;-~~:;/.,~-~%/;<~<><*~::.- ;_;,;... _~* :-~~ ~-:j~~~:.: _ :.:* :_:.. : :'"" *-..- -_::,~._=:-:::-.<~~\\.. -'-~... >-~ *:} *_ -*. <.. -_'.:,~J;,.-;.~t>?-::~~~3,--,~.:.:/.>i;~:*: :... ';_._:~~;<~-':.The* design basis-NPSH caJ.culatiop assumes-complete blockage ofthe*one * * ',"::>;~-....,~.,,- !. *.,:j,<;:<J-.. ~....... }~.-*-~*~=--.....:_,,..,..,.(::,.: ~* - -.. ~... ~ -":.. ; '.*:~ :;--:.-<~,~~i-7; ~-.-;;;,::-;?-.r:--':-:..~:-_ ~".::'~.: ::*: * :.c~*t.. '.~of four:suction strainers in -the most adverse* location. _.Dresden is currently.. *.. * * -. * )~;;.:.':f-~_::}~'.~f~f;J~~;~~~~:-~-~-:}<~:~*~1~-;~;~1'f.*;:rpi~hift~-~i~W~ii_e~ -~trainer:~.~ The~~ ~~e~s

ar~.ilie* larg~st 'tha~ can'bt{

~-~--~,,'. ;,.:.,~\\>:-~.-:~*.-~.-~":::_*:~\\'. -:.::::~*~.. ~.:;:*.~ *_: ::physicallimoved.into-and ins~led in the suppres.sion pool, and have.a.-" - -.. *. --* 't,.;' --.;*.-.,) ;'..,._ ~.t.--:- "~*~* 1!.. ~_*,.-*..,

• r.,

..-, ~~, * *{ , ~ :,"1_..,..;r ~

• ~ * ** -

"/-* I * --Co 1 ---~~:*:.::,:::::.{:'.:}:-t,*:.~~0-i~:,.:~:;, ::,;.;-;*,~-::'./-. '- *.;~~-.J._*c_teap~pres_sur~ dJ:op \\\\:'hich)s much le~ restrictive than the presentlY. :- :. .. ' : ': '\\ *f"'" "~;'>'**-

• • ~*~1~;1-.*-;-_ {'*

""';!: r. * .r.: *. \\.~*.' ~ '*'*~*. JI'.,. L ~* : ~-, -""-:2~'."':~~>,,_*"'~t.7:-~~:'*:~;: _';:,-,~.~\\~'°"~~--,.:;;installe9:* strainers.* *Therefore,:..CoriiEd *has conduded _that Dresden Station. ~ t J{*~;:~ ci.~~(~t.'};:~=t~~~:f.--;~:-;~~atisfies:*the',tl~bri~ efte~is~2 'sct~en block~g({~d pump s~at faililre criteria.. " ~* *' ),,~"_;..j'~;~*;:-';'.r'j._-;:.:'*: >,;~., C, !"~~.:.~,~-4{:..";_::_.:./., ~ * ;-w** 1 t ;*:: r A,_ "* ~ o .. "'"';-~ j~-

• ~*.

~**, .~ ** * * .::..:.-,.-~,_.,.. _,_.. _ --._.. - --. specified for the CHRS m NUREG-0800 * --:.; *,,., "'

• ~, -** : --

-~~~;~E:--\\~).. i;t?~:~l~::f.:~~~~: ~,'~- 0:~i{)~-~~;1r~t;L:*.. :;_;'.5-~~-**.. :~:->~'~!.:~::--:

~_;*._:<.r-~ -*:?.:.<.. ::~:-.*<>~~:::(<-: * * -~ :... : ;~ ~- ~:-_.. - :_~*'..:: __ : ~-;. ~,--. --~ ~~ :* ~

.-, -:.-"i :,: -:~-:~~~ <.;.,.':.':;;:.,_.,~--,-~~"* :~ -~.\\.>"<->.-.*.->.,, ;~*.. *.: :: *, -5.3.8 *:.,Debns -Effects - Thermal Insulation on Recrrculatmg *.,

• ** ;<°. -

":.;:t-!,

• -::'.~,,_.:1:'*..... ~ *...,,...........

-~*:*;_,.c:'*

• ..!.\\

.~ ~

.-_.-:-\\~::;_~.:.~:f~3,;::~:i'.'~.,;~~,:~-.--~."-~)~,:- :_:*\\' ':::Sy~t~rri ~ *;The~~ffe~ts _of debris.such as:~~rmal irn~ulatio1ion recir~ul.at~ng... *.* :*.

r.::.fE~-'Fi:1~:j(;:r'. ::=?~~--~-:.:~<-~>L*----~ =~fluid-systems~..: see'discussion iii' sections3*. 7 arid.:5.3 :i 2.- 4 ~:}:~~1-~!:~~t-~~~~~(J~::~;~;:l ;~t:T::~:-~};<~:~~~(~*~--~}~*<f:'.~:~~&\\.:?.~-:-~i=~:~z~:_&::~*;:"-~~:_,.;'~;).~;::*:/:~:~~-:-~~-:-:';':-t '.="** ~~-*:**/:.;_ ~--:_. _*_. -:_ * ':_:> ~- -~::;:~::~4..:,.;~:;~~l~~:~;:::_;:.~...._._~:..,;':->i:::;-::::;:-:::~:;_,.t,*':~::;.-.:~_:_~d;9.: *'.S~c~m~-Co.~lmg*Syste~~ --~review.of the secqndary--.:

• _...

ji!i~i~~~f ~!~,;~f ili~~F~li!?~~f~~~fil1f~='.

~**....*,

.. :--;, -: >. ),~.:;;~:_~>-",*~~-,;;. ~<<-;-~~{~~* _- :~~:::.-.- -~:*.: suppo:rting !}iis *_amendment.: Based: on the results of those analyses, i;,.::.!::-~t -~"::~-};"':.:.'I'.-_::_.,.. *. ~(>:..* *, ,~.J'r., -.:;. - .,.;J

• -*~";._

~. .:;~~~~;;::~~~l~ti~~L-~_~:fi~;~ ~: :~ ~:~:co~~A:~ ~p~~1~a;a., iliat pr~sden :S~t~<?n__satisfies the *~~~on,~ coolin~,,.* :*._.* -~::~':"'~::_::_~:*~~~-~-:~:;:;;:,~~:,-::::*>*:*~ :*: * -~--:,;,;.\\ -'--'-~~system*cntena*spec1fied-for the~CHRS m NUREG-:.0800>_' *::: :*'; * :.. * -'- ~ :"- '...,. ~=~~~di~~~ J;- ._.5;.,:i +/-~~{;~.:n~i:~;.-;~nsmg.and~aatiatfoir*mstium°diitatlori pr<Nided Jot..tlie contairunent heat'. ;=:-".-. - - l-~ ~- :::-.-.,..;,:,y.:.,:.. :~.-~----- -'-.~.;-_,_.............-! .~:_..... 1~*~.:....... - l;:--*=~~J --)* ~

• ~...:

~*' , :,.1":-~_;:.\\7~3:/;;:-~-~~::removaI.s}'.stems*':.:: ~The-CHRS. is a *mariuiilliinitiated system afDresden* --* *. - . -:".!;.*.......:---:..:;k.;* <.r..":'-...:.. .~ **....,. ~> '

*** ***--..

L.....o.**

~ ., ~ ~ .r Y 1

• ~--"'.o::-~-,'

~'<l'~:~S~qQ.Ji;,;,:J\\.~{;Ji~teJ:i:.ifrRres~enJJFSAR* Secti~n 6:2. i.. ~~8,:a suppression*. ~-." * -.-:,., _., -~**...... -~.. u-.-**:i;:;C,,[-r,-.......,,.. __... r..... ~*~-:-r~~-f.******"'* ""; *..t.,-........ -- ** -,.-.....,..z.. -.. - J.. ~ J r ~"' :1~p~of'.teinP,'erafiife~moruioritig>systeni:is ~iristal1ea.fo:.provide:averageinct ;~\\-o::~.'.-~:-:'J:~': :>~:1,i *:- ~-:-. r.-..::*.. ~- 7,"'"r""':.~.y.. :~.J:.~#;........ :z....._;,;.t-.-....... ~*~ ** : -r-*** *,.. -~"'.. :.r:-,*......l._,--\\* [ ~...

• ~.

-~.-** ~... ~ ** -'--".;.,..

• • .-:';";~10cfil-:' onem erafure':iriOicatiori.EriioJilarin:s~m~the :coiitrol-room.:*c'SiXteen.". /:.-.J"":. *.: '";~,-

~=:- *. ~-.. .. ~.. *.. ~...... - **. *:.. ~. ~ ) ~. ATTACHMENT A. ~.. -

• • • .BACKGROUND AND SAFETY EVALUATION OF. THE PROPOSED CHANGES.

.. the~oco~ple~ are ~nstalled aroUlld the s~ppression pool, one in each bay'..

• with a' set of eight thermowells on the. inner Circ~ference, and another. set..

.~

' :,* *.; :".*. *'. -. of eight thermowells cm the outer circumference,Jormmg two.independent

• * -~
• *.-' ~, ' - **.:*,. channels. :niey *a.re placed below normal water leve-1, near the normal

** ;:;<'J-:,. :.,:ce~ter.. ofgravify-of the water mass and horizontally.equidistant. *The

• \\ ~/ ::

\\(/: ::,;:>mctividucil.sensors for each chaniiel are continuously recorded iri the.. - ~;.'.:

• * -~:.coiltroltomn>The-.coiitainment *pressure and suppressi.on pool water level

~,*.,~,-

,'::~~'::.:' ;*fz//'"*:,:_.: jnstnllnents meetthe require~ents ofNUREG-0578~ Section 2.1.9 arid.

. ;:,*., /;:-. --_{ *:_):~.'. f: f;J_'~* :*:,_-:;'.~t~~: :*~.. ptevide :~ Wider rang~. of.indicatioJ;lS;:.Both ins~t!nts provide indication.., -;il:!Iiil,~111~f iii~~i~~~~~i!£¥i;:1¥I:e **.****. . < *_::_ ;:~.:*:->*:.~.i-~:j/.,_:~£!:'-~~~:":;t:_~_-;*~-~~:'._}--; *;i~#iperatill:e-e'ffects"~n enviio.nmentally*qualified (EQ)'equipmenHoca~ed_ ~ ".*. ~.~-:*:... **~.~* ~~:-.~:-:'"'::--*-;.\\r.~.;..._.\\*ft:,.r;**~"*~'..r.:~~:;.2:.._..-_~-;-::-~*:**.\\":.;.:;-:-**

• _;~... **

~ -1:.:;.:*.. ....':-. ;--;L:: ~.:~~;<_:~'f*;'.:*:c::i~;;iC'.,'.; _,~:-~\\':~m~tJi~ Clrywell can be-deternuned*(se~ UFSAR-Sect1on-3.l_-for a descnpt1on*,..

• • • • ,*~:-::~1~~~tJJ~~1~w:~~~~~~r~t$~~~~:;:~;=~~::~~ciLJ:~;::;.*'...*.... *

., * :;;-". -:'..;~;-! 1 .:.'~l~t*--*.:~r.t': ~~.:_;,:,;:_:.,,:iR."G.:1:97 Program).. Therefore, GomEd.has conduded that-Dresden"._. ~ .... :;* **:-( ,,:~.<;** ~*:.: '.)..~:~-;.-.\\~:**:l:_!:;. ""'""-~.. /.._ ::)~*.~1*-:-M,.. -::::..:-:.* *..:; -~- :~*.,..

• .:* "\\ *--..
• _1

~ *:..,..

• 1

~

_.:;:*--~;~~;.='?-;,.~YJ;_~*-'f~ ~ ~'~::*;":=;.:~tatl<?,g)~t1sfies th~_sensmg and actuat1~Ii mstrumentatl~n cntena -.-.:., -: >...

,.;,/::.::*~--:;.:-i;.':-'~;'....;::;~-:(",f~-~:"::.:-<.... ~.:-"

• -*fi a' -c. "th -CHR.. s-* 'NURE.

'". G 0800 ~.......,.. *:',..,. --... :.-.-.*-- --:--~. *:~.:- ".::-.., _. *..,; ---~_c.:":*iq *':-:-c:j'"',,,. -:~*"'"' ; spec1 _ e -..J.O.r

e.

. m .,..,.. * *,-... ~ *::*:.,.- :,:. *:._, -c..,--,. -

• _ -.. ~, i}.~~?~~;~~:;m~!t{~;~:)~::tf;,:_/\\:~:~:i:.~~J:~~'..~ ~~~:~~}~::- -~_::'.' ~*:;~.-:f y:-.:<'.c*:"-:*:,\\. ~,.~i}/-~.. ~z :* _.: *:_*:<;:.-.7.--_,?- *:t.,

. :.. '*, -,~.,,..~ -;-'<'<::.:,'.. ;... *,-_ /):s*-;~;.~:-:~>>:_-:_:, ~-.-~'.(:.:5.3JT~:EQ.cff the*CHRS.:-,The effects-on Equipment Quruification. ">"'* -..

• Y* *........ ~: "r *

~:~..,~;.--.;*t;'~\\: ~;;:;._~:. *:~*;.r- ,',~*,W

• - ':" l..e--,.,. \\~...,,;,.fV~

r ~ ~ . *: ;...-~ :_::_.... ;-_:_:_';.:~~*::£-~!~~-,~-~~.~-; __ "e::-.;:\\-:_,'.~(EQ).r~garding.the:qualification tes~ program for the.active.components *of.'"- .. ~:.;.

~. ': :~;:;;~-~~,<t~~:.. ;;:;:::::::,_~_f;ef,,':< -.ihe~LP,Cli'CCS\\\\(fan cool~r :system, arid the sensing and actuation :. * " -'* :.

. *:.. _ -~--~-,~~/f9~~£~:.;~t~~;~{~fkr5:;~~.:~4i~~¢n~ti5n.ri~~~-~-~n~~n.t,~e_a~ r~~o~~-~ ~~ :~es~~~~q_in"_.'.;. *::: ~:. ' __... :....... _" . -- * * -_ ::.. :~_, -: _::;,.~;r *:':::;'z.'. ;.~,..- *ir'."-="=:~~;,;7,;:;.Presden_:UJ'.$.AR Sectio.n 3:1, the.envrronmenful-*quahficatJ.on (EQ) of* *

• ~*-

....-"<-'(*";~*-.--'- ,_,,,,,_.*,._,..... r. ~ ~*,.'

• ~

- ---.* ~-,:c:<~~,~~~:i}P"'~~~-~::'*_,;0~~:~; --~electrlcal_,eqµipnieiif(ot,Diesden'Sfution:ls'peifoirtled per'the.gtiidelines or-.: ..=' ....... **::,_"t:*:._.,_.-",;~*.:-;~!l"~*;;c-~-.:*.. *;_:..... ;~~::..:;;"!.::~*-*' .. ;.... ~,- "~ "'/...... .:.*... --~.. : *>::!:'.,*::;."\\_;--;c::"*:'t:r.*,_.~._,,,~#:J<<.~NRCJE)~lUletm\\79-QlB. and the:requrremen~*of-.10,~FR 50.49. ~After.the -. . *-_:*'>>= ;r\\-~~:'-:i~\\~.0~-}¥3:~t::i.:;~~\\i~swmc~~-ot~iE:Bwfoim*19:ois;~coihEd.suB~tted a::'response*fo th~**NRc, _ -;--;":;~... ~-.:¥....... -'t'"-,,::,.:;-::...,.,.., -~~--.* ~.

--.~

.,.._.*,,*~~*

• 1*,--:;_,.,.. -

.i' '~-* __ -,,--,._ : ~ --*~:_._ ~;j*.-~~":._ -~:-" ___ ::;~*:.'(~*/~[~:;;in ~liicli-the* coriipliance.methodo_logy w:as deli~~ated and* a-Ii.st o~... -- *

• ._ *~ _. *

... ~;r*~-~;.-~:-.-;~~~~-~:t~;-~~:~~:*~~">*:~~\\*~-~t-~.. ~-bo:.niPOneiltS*.io*be quat{fied was encloSed. "In Jllne of I98I~~the.NRC. ' \\ _:

• .****.*.. ~,tI~~~~~~~}~~~Ji~ti;~~~iS~;a~t&~!~:;:~tlon ***. ... *.*.*;*******.

  .,.,-" _ *. _,,: :*".,;;1,_."_.,;>*:.,,..,~,.;._,...,~,*-~*{***.";,;,.C_offiEd,filong.~jh.a,;fechnic;al Evalua~1011 Report_ (T.E~}l)l.D~cemb.~r;

,*~.*-.-.. _,,,,,. - r*.*

. " ~... I. ' ATTACHMENT A

• .. BACKGROUND AND SAFETY EVALUATION OF THE PROPOSED CHANGES.

2 and 3, except for replacement equipment, may be qualified to :the criteria sp~Cified in *either the Division of Operating Reactors (DOR) Guidelines . or NUREG-0588. *Replacement equipment installed subsequent to

• .** *:_ :'*'.,~~-"*'... *-!

~February 22, J 983,*.mustbe q~alified in accordance with the provisions of * .... ~:.~*....,...

• • *.* ~lO.CFR 50.49;'iusi~g the guidance-of Regulatory Guid~ 1.89, unless

".-.. \\otherWise justified. Per the requfrements of t'O CFRS0.49, each licen~ee . **-:*~:~L:<.~::~~>-:}~.;*'.:-.. '.*.';~**>.-~u~t e$tilblish*a.program to environmentally qti~lify-electrical equipment..

*: -~,:.:._*'.::,::.**;_..;!;:. ~'.-1'X.* ~.-;* "7~.>><~ ~:~.~~"*.,:.Co_~ *has ~valuated the. revised analys~s ~d its affect upon long-term * :.. *

• .. *:..: ;::*~~:{).=?;;~~:~; ;~~-:~{.~;{'::,~;~*:;::. }*f::::~co'n:fuinment. pressures arid containment parameter temperatures. Existing*.'

.~: :~~-:'~,~~~:' *~~~.J.,.'.f;~: '.t~~::-~f-ff~t~)f:;;:,-;:~i~-,:~:~~~~P; larit,CHRS"and low.p* *ressur~ ~EC Cs pump *0-peration*.regarding the affects* ~

.t\\*~.;\\*.*'I';::'

">~*'

• v.... *

~::.....-:=*i,~\\""'- ~'"T ';' ;*-. ~.- ~ '* ~ +-,,, - I .*. ~ -. :.. ~ >-'~>, *;~~~~::,:.*~~:.~~~.:z~~~~~F-~t\\~;:.((~~~:~;).9n\\plant-equipmen~ qualification (EQ), hav~ been shown not to*be . :.:.~r:i/~~~{?~r~~'~t;~::;;_~~f~:t~"J~:t\\II~:~~J~fi:~~yetse1~* ~~c.!e~ ~y tli~ propo~ed ~hanges*in analytical ~ethods and:.'..., *.- *.* '.>*,:: --;;~-_.. ::~~,~~~f::~:,tf:;:g.~f:£?.;;9~~~;:;;ye~illts,-:ev"eii-illough"the new ancilyses result in a *higher peak suppression

• ~.-'

.,Tij~ff;,~&?J,if"~!)~:~:.~~j;~}~'.'~;p601* temper~hire.~* The affec~ed illstnniientation ~ema1ns bounded by * :'_ :- . ~:~-~ _.;~t~... :..::;.... /.. :,,.~.-:°1:"':f... i:.::':.:~... ~:.-*::o.&-'i...;-;i:**~*-~.*1*'-. -~... : *.,......

.,-,...

:::t:~f~~).~-*~::~:.::z.;.--i";}."-~:t*-'P*:.'.'.~~:.i~'.:;~xistmg*quahfication;Clata. ::The equipment required to operate to*support,. *

• ,..,..; <" >::....... -:.--~:-.;:...~:,:*~~-.:~~-:;:.. ~ ~~ *-':.t~-~t:.-i..-";'.- ~"... **.-:.~

t >-':.'.......- --:'~.;.)~~*:/*'.::;r..:::"'C.-.~-:-,.*-z.,~'.-':::>--. ~... ~.CHRS and"low_pressur~ ECCS pump operation after an accident is .~""":'.-~'-..... ~l.-:*~~...... _,,.._,,-<:C.. I,:-- .,~-1-r.;,,..,.1~f.. *. °'='"'""t ~,..,":',. * '~ . ;_.. ;'...r.: ~~~r.:~ 0~1;~..,_~~.;~.;;':::;?{::::'."::.~::.::~:::. i~~~:giialified to_these:higher temperatures~-- As such, containment heat removal**. *

• ~-, -._,~.. :--- ---~"'.*~:*~,.. -.::l.;'1-.',.~.-., ""s~*-"~.-:.

. b**1*.-

....th. -th ECC-.S,. b*1*

. d.

.. r"~*r..;~.. ~

1 *5:z*/~,}iJ;,:.,.~-~~"~.:~:~:;,:!~;;~~:;-;~r..:c~pa} ~ty~~:conJunction wi . e. capa i 1ty is.not compromise. * ~, .,.:.,~;-:;~:-:*~t{:.,F::'.':,.t~-~--;:~~'}~:)?;"'.*~-~:~:~:r~\\Se~~Sectioli 5:*5.2 for a discussion* of the effectS on. the LPCI and Core - *.>.. "" " ~~y~:~~*-;J-f1i~.-;f.~.~~~;:{_~~:*~~-:~*.r-.. ~£?f:.::::*::~!...~ -:_-:"=*'*~ -;.;.*... -;f ~,..-.~*-~: .;~ * * :--.:...... *.:r~-';-.t~ ,,. ~ ~7 ~. ~~.. * *- ~-

• 'i.c**~.;-.. *~-

.. ~---"**:,*.:.*""**t-......,,.. ??Spray-pumpmotorbeanngs.,.. *:..., {9.f.~~~~~i~~ ~~$~!~~£~~~~~*~J.~~f=1;~*{t;~ir~:f~-!t}?jt~*~*;,~ __ *,;=-~... -~::-!:~;t;:~~.'~:~~:,:,.. ~._.~:~~-:> *.; : :: ;; ~. ._ --~..... :-* *~ . _;'::~'. :}~;<~J\\:~...;:-<:t;:;:*.. ~; :1,:~:?.:p.;.. ~;:;.;Therefore~:GonIBffluis-conCluded that Dresden~ Station satisfies the --.

• ~**=::,*:::.~~~:f... :;:.~~~~.;~.::?!:~,;;s;..:;"':::.?[-,::,:i-'i:.~:i-~.. ~;-S\\*~ '"-t

--~.**,.-.,.!_:~-"';<.,. -.~ * ~ 'j'".1-~ I,,*

2 -.. :..-'-~ '*';

• -:-_, --;1 '.".. :\\f

~*:: ;.~. ~;;-.~.'.*.': ~::'_'.:",'.":~':,i':~:-:.'!'_::.1£µ".'rronm~~@:Quahfi~ation cntena spec1fied:for the CHRS m NUREG-. j{~~~!li~~~£~~1*~~~f~:!;s~r1Z3~!~ri~.prun, ~:~*EvllJ~~ -~e*q~ticy ~* ***. ***;*_. *.~.~-. *. '.t:,'::~"f;~:::~~~(~}~~;~?ifC~:I~;;)';\\l~""2~~~~q~ified-p~t.. fu~t can potentiatly reach"the"erriergency*sump(s) unde~ _, *.. *

• .,.*,..f-'... \\-'~-

  -:~*:;:. ?J.,-:;:.::;:_,..;,-~.=:::,-::

~;~' *-._-: ~_:--r,:~:;;t!fl:'-,_ ,..,. -* r--* -*1 ~.- ~ -** *'- .,~ **:: -

• ~
• r

s

' *~~'{~~~:~.~~~*:;~*;~~-~*~;:~r;t }i:.--:£";-,'..{.~;,~;.\\>aesigii:ba5is*pij)e-break accidentS::. The_ evaluation of coating Within the... '.'

-:,ti.--...:~*;..-... _:.-.. -.---..~... --.. ---~-.-*,-..... ~_......;-*.:*,... ...... ~-., t*

• c'.~?}~_i~:\\,::i~*

-~};f~l;E~~;~;f,;~_Qfe~~en~D~C?ll~anq suppression ~haniJ:>e~ i_s contain~d in UFS~ ~ection...... -~* \\.. -

~1}~~"'~?~~~~

...

.i".-~;Y2~-f~-:t;::"~~;6:*1:2:~th:e'i)filniih'isystems;-both ill the *aryweiLancr iri-the:toru5,-are * *.. "... :... : '"- ~ ~---**~ ~

• ~ cf ethefWith~peiidaic1iiispection.-~dfoamteriance;*!niake tlfe possibilicy* of* '.:.- *

~*,-*.

ATTACHMENT A

_,,.~ *, ). -.

• "':~* *.'..

. ~. *.*.. -. ,:::BACKGROuND AND SAFETY EVALUATION OF THE PROPOSED CHANGES ~... ___, __ ~--- _ :'-* -:-::*- -: ECCS strairier clogging due to coating failure after an accident, remote. "~ -- - --~; ':> ": _ * - -_ <' :: Therefore, ComEd h~ concluded that Dresden Station satisfies the

• r :.*, _. *.

unqualified paint quandtY criteria specifie4.for the CHRS in NUREG- _:>_:~~::<::.~.-:v~-.:.0800_:--,., -*~~>~.~-~~;*.. ~:~;~---~>.:~*;-..... ~,~~,**;".:!:..,~:~--,~~~.... _, -*... '<-. -*.J_-:*_.. ~**.* ~

• ~,

_~2;_:;*;:;,'.;<!';}i*::;~:~:::~:-~~->'~:-,;,~:~.. ; _,,,,., ; * -S3.13 *fis~io_n Product_ Control Features of the CHRS - The fission

• T~*:_;;,::+~'y_~-"::~-:~_2:::;"1i~(:/i;:~/.}::

• _-producfcontrol *feaiures-ofilie containnient heat removal system._ No '

'-:; -:.. :.:~::_:*~r~~-~~-~,~~~;-:;~:.~;~i;,JJf::"-~:::-.credifis' ~en*in the acddent*an~yses for the-contai~ent spray fission ._* :..,.,.~

• -

  :,... -** ~

~.. "J ,- i)(..,...., *' r - *.- -_--:-;."'..:-~:-.*>---:.*.'.~:~ --,:~~_:(.,-~, -:._ ~-:-;,:__'.;r_ ( -* *.product,iemoval.cap'abilitY. -~However, the requirement to* maintain the 20 ~: ?~/.'.!.~-,~ :;~;.j<:;) *~:.-~:r--~:;\\ :<~t::_, ~ ::.-:_p~id _p!ess~e d~~ereniial: ~rep~~sent~ _a *fission product control f~ature ~f the_

.;-'~,~--r.<~-'{

~::;_:~lt::~::>~~;:*/:\\\\i<... ;:::CHRS.-~~This requirement is µnchangedfrom the original and current- _ - *

,l<:.,,."r..,~,:_~_:..::**:=-t:7:.~.}::-~~.... *... *r,t.: -',,~-;*~-~- *-- *; ' --. ~~. - .~.* ~ ~* _ _, -,_: ::_,:;-:. ~::;.._: '~.*:_::;;;.:/-:_.";- h,~::-~:::::~~-~~--;Jicerµnng basis for the_plan~. Therefore,.ComEd has concluded that - -_ * '\\: *~,jz!_(~~/{~;~~;;.;~;~.?~~~!.ff~:~::;:_,~1~::; }'niesden':Station s~ti~fie's the fission' product control criteria specified for' ..._.,*-, -*.,\\-:- -~ [ ; ~.(\\g1_<< ~-:~~......;i,;~...... t..~~:"";.. < ~y~ - ~-.-. ~~. ,, -'------~---~--- 0 *-~*"'-'*"---,-.~----** --~-'*'"'"--the*-cHRS m*NUREG 0800, * - --~*~;:3~~~~~t¥J~jf7t~~~ti~~r?~~:~~~~~j~:~:ji~-::;>~<:::-f, __ :*::... /~~*~:~~-+/--;*:*~~::::-.::~:~"-. *: : -_ :':~ _ * /:-- ~--- :_-_ :_._-_

• __ --- -.-: _

-~.- ~ :.. ~ -- --, :..,.~.:,,*i_,~,,-~;~~- -,~ ;,,;'.:--,-. -:t-;'~-!;;,.::~2:1'\\~. _-i~:<; :; ~--_: __ ;* ~'-~S-3 :l 4 *_System Seisrtjic Design and Quality Group Classification -

• ?!'?'-~J'l!'*_..~

  :*.~,...-,.,,

':::.'-J'-\\'... ~~,:'-.,,::".~ *...l.- -i~,.!

• ~
• ~*,
• .~... r t

'--__*,-;:--: :~::-~>::_-c: :\\:;_;:i:::~t_;_.:.~_;:t~-:-:.~~~-::I;::~.;;:i>;::The:system~ seismi~,design and _qµality group _classification.: Bo~*the. : 1..,,.,_,_,..-;'I;

• .-'-.,,*,M,'t.';:?:~.!-,_*,,._-!:*.~J.. ~~:--..-\\fo';.<:>.:!,1..*'~1,L1-""°

~* *

• 1 '

• • *"-~* *;.*.'/

~ --~ __.:~-::--~:*,-t;~,::*,_-;:,.v*~:.::~;~z '.~:.::\\*-~-' -:-;"'::*::--*,~-;:-,,;LPCI-and-~ccs:W sy* stems. are:safety* -related, seisffilc category -L systems * ~ - t ~. l "'"t* ~.......

---

~~ c-\\!~2';_~,~;.;:sf*~ <~{-~ t~~}r,f.,~~'.t'.~;:~f~-:*:{::\\(see:*tiFsAR.:~3.2.2).. _Both-:redundant loops of LPCI/CCSW are powered - -

~.. L .':..~J'1 ..,J"'*l,,J ~~::.c.*..,1~'1,---..">"*-.*t' ~* ~ f>'

'~* -~:,r=;.\\_.-}.:.;/i:'-ii ;/:S'.>':'*!.*~-'-"isif.~~:~;:?';:

• 0b'y'.~*eparafo-,safety-. -related electrlcal divisions each fed by its *own. --

~~: -I.. ~:~--J-~~~~-4""--:*.. -~:.-';;--::-:>.;-~-.'.,:~* ~~q:.:-~""-ft;-.:.:.* ~. 7

\\. -.

~ -_:;* r* -~~:~~~~:~i.~~r,---~- 7 -r ---~<!::~;-~\\?:"'J;:ajergeiic~fDie.seJ;Geri~r~tor~(sefU.fSAR.8.3):- For ASME-Secifon XI __ *.:*-. -__ :**, ~. ~;i .::~~;:,ft;:~;,~~--- ~~;~'"'.: - *- :-~;~pi.ll]J'ose!?.;*:LP~:H~i~-considerea _a;Cfas~'2_system 'to"tlie 'outboard reactor-: -. ~.,.~: _ -" --.... - --

...

..;.._.,!~-

,._::.~~-=.:... ~...., ;':.~zr::-= -."-.~~ *-:"' -..::

-. --: :#~ *--.-,,, --. -. *- *.-~*.. -.

~. ~ ~

• *- -.. *, *~,

  .j __ ::.~i37':??-:;;:~~-

1-:l:**~;};ft~,;;;..~:;.y-,i._.~, :~;:,_o;:}:';)vess~l isolation,valv~;-.":LPCI is considered.a Class 1-system from the

e-

;..-.*:-"'-*-t.:!'i;:.::_'.~*~....... :-:;-.,..,':..

• r

'~- "**1"*"'=~*~;~_,_...,.

• • ~*-.*...,I,--..
  • -' -~' -...,,*

~.-,...

• - - *:~.:-;.;-.. ',r*,,*;::-;: __ :.::~:-:-;2/::-~:]';~:,~.~-~'->}';") '.:-~-:outboard isolationvruve.fo the reactor-vessel. *Tue CCSW system is * -.

-. ~.:.:.. ~::.-~.. : :: -.. ~: ', ~.... ~~- -~:.. :--,:;t --:,*,;;*~;_.-....... ~;,:*-.st.. J: *,}-"": -* ":~..... _ '. ~; :* \\..... :~ '..... *.. -; _.... '. ' -. ~ -~*;/~-,;*i-i::t~~--,~:,~~;:::<\\£'z-r;,_~~:,£_**:-~~-'.,.'.c_onsider~d.to:be_a,Cl~s) system_(see UfSAR'Figures 6.3-7A;6.3-7B,--

• ~~;:.>.*

I,!;*" ).. - ..;.,'"**-~*j*"**.* 'f***7: '.l-

• ,,~l L

~- 1* ~ I**

• ~- *,;f~7~i'~-f ;~:=:~::);",;~- :-i~'_;;p::-,:,?:*f:~**f~0;_ 9*~2~1 ~an~ ~9.2.::~) :~Therefore; because* th~ LPG! and CCS W-systems are. -

• .::!.......,..................... _,,_....,'f".;.......... -r,1~-t,."i ~:~::.--::--..-~.....,~.. 11.;,..

,.. ~.. ~*"' -1 1 ':*1~*'*:*-./..;.~l*;, ***7.,......... _. j:*!t~':~-';:~"~'J;~:~'::;!.,;,;,%~;,:'f~-':;:,'.;~)-,---.~'.}';;;;;:~::,safety-,.i¢lated*seismic-eategory [systems and meet the appropriate quality -- -

• • ,-*>>::~;-~*;-:;**,:i~!i"---.-c~-t-*.:-~1*:**-.~;,x.-~*.:},:;f-7;.""\\.*~.:*....:-.*-~~-<.. ~*--..*-,_

.. :*... -*.!:~~.-1 -.-'l-.... *J..~ --~-~:~_-... :..

• .. ~

_:*':t~:~~~"~*-j:}~~::~;S;:~~~~-**:r'~"'-:~~~-~;:;i~G,group:cJas~ifjca~.o~_ieqUJre~ents.ofASME Sect10~*XI; ComEd:has_ -. - _.._*: :.. t~.,1-*.. '"'-'* 0 ":.;i.)~ -..\\.-............1.**'*-q,t-"*-'--~-.:l':***':;,-""' ,J -----*-**t..---*** l w~~N~~F ~~2;:¥"'~-ir;;¥,~j;::.:-:~1?:~- . -,;:-"con_~luae~'tha~;pr, _e-~den S~tion's~tisfies the system sei~mi~ ~esign an __ d :" -*,_--_.. ~,.._~r,, 1~ W-.ti~..,.}:f;*-~f'.:i;;*-:>i0-"'>:' 'Y-'!*_ ~:-,.*:,~.G:-~ :;-.:;:-.-*%-_,:*..!'~£1'..ci*" .!-~:;~.:...-~.. ~;-~* *. ',,..,.,,, 7 I* ':ic!;::}}:~ {~,{~:~i~~),~'.f-t~t'.~.,"-,~-r;~,i".19\\@~t¥_,~9up-_~!ass!~ca_!l~W cn_~e~-~ specifie~:f9r.the*C;HRS.m'NUREG- -:-.:, -. /:.:i1,~;,~~~:::_: 3~~;___~:.~;_:_;;,-f.. ~2~f :~~,.:.::X:.:_:~~\\i~*i;requiremeiit~dor~ an engineered safety feature as if can accommodate.a ~

• _,

~-~~.-5:.t...::-~:)~*~~:~~~\\J~~::~-=;i-l:~-.~~~~~::~.:.:.:--,,};.. \\:;E?.\\~....... *,.. :.~.;-.;*~;.. _1)-

• ... ~--...;*~-~
  • ~*-*

~ *. ~: ~-;;,'i:~~f'iC.°"7!i:f-5;;._~iJ1~7'~:£~:_.>~ ";. ~fy;/-,s~gl~.-a~tiv~Jailurf'..~,;pie.:D~e_sden CHRS_is capable~ofw,i~dmg ~-- --~~~fi~~~~~ 1 ~? ~~?~: *-;

SE~,~~~{!if}~~~;~~~~iit'.1,~~'.~.'~ftu.~~ii.~~; ;'.f?er~for,e,--~§tallse *t.h~--~~-~s_:can:) ~---.- ':-:_:':_.: _

... ;,z*<ir+c;:* {_:;.;: _"'""'"-S;;.i:ac_c<?mn19d,1:1t~~~"~µig!~*activt:::f~lur~,-pomJ~cl:h~.~concluded.that Dres<J~n _, ;,/.. -. __ -.;_-__, __.,, -7J:.r~~-~~"':'"i __.r.:~.....,,... ~ *. ~~..... *.:*-'._:_,:-:=~*t.z"**-.-.-;.~.-:-.*-::*,.:.** ;*;:-*-,...... ~ *r**.*-.-" ~""-.*.,..~**. ***': -,,_ . I'*.;* ~ ~ -_,_ -- - Sµitiqn_satt~fie$'.'.th~~smgk-fa_!Jufe:cntena for the*Cffi,lS;_specifiea'mJ O,.,_'_ 1

• • '_ ~---_.,

• ~ *.:-*..
• !. ~..

~. -~.. \\ *.

• ATTACHMENT A

. BACKGROUND AND SAFETY EVALUATION OF THE PROPOSED CHANGES 5.-4.2.Pump Cavitation - An NPSH analysis was performed for

• the LPCI/CS pumps under the long term and short terin conditions

. *.outlined in Sections 4.2.17, 4.2.18, 5.2.17and 5.2.18. Inputs were..

-*. selected to minimize NPSH inargin. *

~

> >, -. * ->. :**:: *'.GomEd's supporting analysis shows thatthat the a~ailable NJ>SH is *

~-:.:: : ** greater thrui'the required NPSHwhen: c.ontainment pressu:re is properly

~~--~_<~*~.:\\'~

.. - **** '. takeii'into account (See Section 5.4.3). Therefore, ComEd has concluded

~ ~~,

,\\o~*~*}.;.{'~~:* '**

. __.*.'tfo1t:Diesden:$.tati~ri.satl.sfies the.pllinp cavitation criteria for the CHRS, . ;*,.,,:-.*~_,;~--,:::;,~j:'.~: . :. _:*<.<speCifiecfin 1'0 CFR so*,~Appendix A, Ctjteric>n' 38..,,.

• .:.***-:**-,).*-~-,:
  • *.,*.*.*.*~---~~.*.**.* ***

.~ *** :.:._,**~:*:.:**,.:

• ~

~ ~*. ~,:* * * ~

• - *:* *~ '

r.. 1 4 ~ f ~

• .'*'.-',:.<_-::,,/~~r*~.'.. **

~

• '.5.4.3.Reliance on, Containment OVerpressurization - Conilid's
• '; 'F* :- * -

 ?','.~-.-"*-:'.J.:NJ>SH analysis, does not satisfy-:the guidruice provided !nRegul_atory * ~'.:,:;_ 1 _:~.;~t_*_::.*_;}_f_tt*i *,.JXY:~=~!; 1

• i%:J~~~i~m::i~~.~;~1:m~=.~~::~~~~:mr!:*. *

.:~.'.*: *:*. *Regulatorf'Guide f.t*is in* accordance with ihe CHRS and ECCS design_* ~:_}::>~~ ;{ :>::f *.. '_;~,*: * >:_i;~: *~-~~>:))>~is~at p~es~~~ -*Station.. ~1)i¥:'.NJ'SH_ and cpntai1~rrit~nt_.conditions were _,':* ~... ;,. "' . :-.,-. -, ~'-~'-. 7~ ::-<,\\:,:-:- !'.< *;.~:~,:c9nseI"Yatiydy~calculate~:.5he.refore; Coi:nE<fhas conCluded that Dresden?.. --. - }~:_:.('J~f.. _.*'..::**.-.*:: __ --_,:_,,*.-.*::*_:~.,.;~_::::*:*~----.-_i_*,'.... ' \\ ::.f.?;*~f~~;bi:~{6't1;it~~~=_:~i:iV:6;~t,:~~ frit~~fo;lh* ~HR~.. ) -~ r- -~~:~~~~~~~~~aJ*~~J~.-.~ ~-;:

t;*;!9;~~!~~

!' :; C(\\ ::t;;1~:/t!~1°::~~::~==i=:~::*;t~~;::0~0~~s:f *.... *.

• .-*...co~cluded*that-Ores'den:Sta#Ori satisfiesthe'.1'fPSH.c_riteria for the.CHRS, *:.. '*
• '-"-./<**:*:/i~~:~~L.~'.:~::::-:-.* :i-.~:*~*::.:_~-,_,_--.. >specified w)O_ GFR_-so;.jl\\ppendix* *. (.Criterion.38/.:...:'. : _.--... _.-' *.

,"~~ H-:_;;i~~~~~*:\\>;.:\\~-~~; ~.. :~~::\\~ ---:~... -.. *

./;~~) ;\\.:~: ;~ -5 ~rs* ~j;:2i~i~;~s~;/~i~~~~i~:~6~~~~t ~~~H~~ 'c~p~biHty~ii _:.. : : ~.*: ~:

(~:~-:f'i.;~:~~5/;-,~/~,::-:~f~-.'./ <:~ ::;* ;~-)-;'.;:;.. ~)lepenaentoxi"the.:LPCI"flqw rates _through,.theLPCI.°Heat Exchanger and: :, : :.....

-~;;~

.~'.::.",~:.~i;.:':~;<~"-~... -_::--: :_* "<';:_:*.; **: '-'-~'..>:.. not ihe; spray:~o~erige*.-~- Mixing* efficiencie~I of the* contilirunent sprays *-:- ". * -..

,;.. :.:.. ;.).,:."~--:;;>.:.:.-.~.~-,.{~.. -~*\\,.'::;.~-.. ~- .~.;~-.-~":..-~~::... :',.-,-.'--:.:*.. **- _,!. -... ~*.:'*,: ,,--..* r*- .:-.* 1.,*~ *. **

~.

. -~~:_:. ;~-6Y~ * ;::/;_~: * *i

:: : ;:... : ;*'::-,~<:::have '.been. used m~the analysis to produce*conservat1ve -restilts relat1ve..to..---. * *

,.;f-".'. ~.rt,.

;!f.:~;;.:,.::£'.~:-~:~ "f:,J:.-;~,_:;;;;.:*:,._:;:'~:'LO.CA ~_ignaJ.,_'fhe.. refore~_no.credit;is *4tken for their* heat removal

• • ,:,,...::-~~.,.;:,.,--.* ~;*.:.._....'f/._.,,,t *.,..
• ~:

~I~: -*~**""' **_,~ -...-~' ... ~

• ~'

ft~~> '~\\:.'--:_:!2~;-;j.;;_~:;:, ".-*:-~~~-i~:Jf~,:.~-:"C?-~P~q~li:ti~~ipa~f.of_tb-~-{:9~~~1_1t.~e~(R~m1:rv~.Sys_!em (CHRS):' ;. : _.-

c. __ *.: "

ATTACHMENT A B.ACKGROUND AND SAFETY. EVALUATION OF THE PROPOSED CHANGES 5.4.7.. Surface Fouling Potential - In.evaluating the heat removal*. capability of the containment heat removal system, Dresden Station has

• accounted for the potential of surface. fouling. of the secondary* sides of the

. :* fari.coole,r,' reCirculation, and LPCiheat exchangers, by the cooling water,

• : over :the iifeofthe pl~t. The effect of surface fouling on the heat removal.

capacity of the heat exchangers has been analyzed and the i;esults have .. -~,'_<_,*:.. *. been*pteviously discussed m*;section 5_3.5 of this.report. hi.addition,.. * .. ; '.:: >. : :'. :,.. -. '.. *. surface fowing'has been accqilnted for.in establishing the heat removal. -::.-... _;}:::: ~ ~~:;.*:_:o*;.. ' ". *.* <cap~~ilitY oftl,ie-~e~t e~ch~gers.. Th~refore, ConlEd has concluded that. ... ::~'.. *.~

• ....,, *.** * *--.:~
• . : Dresden*. StatiOn satiSfies the. stitface fouling criteria for the CHRS, *.
• >u~/~/**....: *.. _ -<-::.* :... *,~pecified ffi*10_CFR 5Q;Append~x A,.<;:rlt~rion 38.. *,

' '*:,..~ ~'.'. ~ -...... ".:.:'C : *>_;;:"":: ~ ';-.::.~~-~::,.\\,:':*:",..::~;::;.,./,;~.::~. >

• '.~.*>:::::;~..-.

~:-:* '.-:~ *... *;...., '.. : :. --**.

• .' * *.:~:

. ~'.. *. '**. *::-*: ** .... '< ;':?.4,R::*'Containm~nt.Eme~gency.Surrzps (Suppressi9_n Pool)-..

• ~.

,\\.*; . _.: <-1.

• ,. ~ ". *{

~* .. ~ :. ATTACHMENT A . BACKGROUND AND$AFETY EVALUATION OF THE PROPOSED CHANGES

• . b~esden Station, an approved periqdic Testing (IST) Program for the
• '.CHRS system components that ensures the.. appropriate CHRS design.
• . provisions ~e maintained~ ln addition, th~*approved IST programs.ensure*
  • *. :; the*continued operabilitytesting of each system or component. Ther~fore, *

.ComEd has concluded that Dresden Stati.on satisfiesJST criteria specified in'J.0 CFR 50, Appendix A, Criterion 39 and40, respectively'.'..: . i f*:.'.

• .r t ;'.:

. ~ ,... *: :.*.*-.*;<*,-S.4:1L CHRS,lristrumentation ~*As dis~us~ed*in Section 53.10 of

• • . :~-::_~'.it*(c{:}: ~~~:~.. ~.:>*** _
• " :*. -.:this*report, the CHRS is a manually'initiated S,ysteni ~t Dresqeri Station.* _*

~J s _.*~ :"~ :~0._-.;:.*':,:**~\\ '* '.';

-:*:.._, **.mstrunient5'meet the reqwrenients of.Section* 2.L9 ofNUREG~0578,...

• • -*-*.I:.*... :.. ~.. *** *.._*,..,

.~.:. *.*. ~ ~( -.. -;:~;_.,:,~::~~;:Xi;;:'::~/." v<-:;::*<>--~ :Both.instrwrient&pro\\iide indication in the coritrol-room.The*system *::....c.*..

• 1 *

<~~

ff,f~;~;,~:t~[~~J]f*;~~~fI.f~TfY~~*. -*morn~a.~g.. irig~e11tcition 'is e:n~_i~on.menta}iy.ci#}ifie~ :(EQ) and *s~ti~fies :..' :;.

• . : '-:;.,.,,-...,.',-;.;-;<<_.;,>o::.:"'*,0-__ -**
  • ,. the requirements ofRegulatoryGwde 1.97. Therefore, ComEd has. : '_

~* ~:~~*:2:N~~~tf~'~'/E:*~:.:".:. ;*: ***~'.,co~~Jiicie~-tha_t Dresden ~ta!f,<>n~at~s~.~s.. ~e:c~s-i!}s~~ntatlon crite!ia -** -:.*, ---~*-'- ~.;-".. *.,_ "spec1fied-m-10-CFR-50--Append1xA Cntenon38" *>.. - - -*-~* --~.*.'.*

• • • • ~**

~ ~ ~- *s.s

• -.* '-1:.

~.. ;. . \\* .).. ~.

• ,:* **-*."='

...' ~ -. ~*. : .....,o:..;:c.,.*.. :L~;:rc,;0;~:.. ;t,:=;-:~~-'-:,),... ::.. : *c. -..-,. 4000to 6000 gal/mm.. )t.i~.thus.concluded that.no overload will occur for.. -.~~3,:;:,{~:(.6Jg,.:";;-g~;::-~~\\{ t;~/f; :~.. -* '.f*-'e}ther the*:LPCl-or ;fo~.the emergency :diesel. generator_po~ering them jJi

• _'.. :* :;:.. : ~ **:..

~ *._:_".?::::~:;,1~~;~:;;/.:~~=rt;~--;.':'_:::<..

~ **the event qf a lqss* of offsite power~~~.. The*impacfofhigher than ~ated -~ ":.* _ *: '__. .. "*:_-.'.~ :.J~~;~:-~::,~.,i~~::.-::*:-'.{.\\;::~~"'-~ *:'.~: * --.* p~p flow.on tlie b~e hors~iio~er requirements for-the'.motors ha5 been.-.. *.,* *;.~- * -~ "*.'.-~-~-.-",>:."'-.... '_?.... l.\\1?;.. '":-7'-:*..-1*, :A:-**;:.. :.~* *',\\.. .::,** *~ .1 ~.* .~ -~' -.,_, __ -.:t.:.~~~~~-~'"'i*~;."::_:'.-::/J~--::-.,_ :~:-.:.;-.""':reviewed and th~ ~onclus1on,in-the:UFSAR.1s*not.changed:-_':*.--'.. -._: * *: :*.-* ... *: \\. 0

• ~~~/

  i

  ~~:}:,*;~t:~

1 .. '.>_:'-:...,* ". 2. :'~. :.* *. ~. ':'. _ ,* *.. *.: : *;*"..,*:~_;-:};;'::~)\\,.' *;;e<~,.':;*~~;.. *:*:-.""::--:.:,:-.~-,;*:~*-:<:<.*;_<~::. -*:.. ~')~.~*:>~. :*,**. :. '.,:'.'. '.. * **, * -::.. ;:~* :::: ~;

.. "~ -.';;'~';~!\\'\\"

;:';:'.\\~--::_::.~._

-~. " -* .1Jie horsepower teqtµrements dµi:mg cavitating conditions are roughly = _,:._::n *_..'::\\:\\'.;i:/-.:'.; -" ::-- .*:. *.* *:.=constant for a spedfied flow. rate. Hors¢power chang~s.obsery~d in*: . > 2:..~*,if-<i~/._<\\~:( ~.,'.:~._:<.. " * :-.*. -~Cavitation :rest Report(SectioliJ.3_.ISfwere generally slightly in the. ~-,. ~~~~.~'.::;-, "* *; :::.. * ;"~'-f:.*~::~-i\\~-~~~,::*-"~ *'*" ":; ~.- ., *-~.---:~-' :::.*:::.*"-5"5:2"'-':Moior JJiiaFiiig.Coo"/ing"Wafei-'-Temperaiure ;**The original... -. "- -..: ~*:-:'.**~-~:~~:.;:*'2'~--"Yj'::~*;,--\\._l:~-: -~-~.. **~* ~--!,*~.;.~t.--~. '. ~*- ~.....,.. '-*-~*.....,. -,,- ~ i* ~ ( .1 - .. ?

• • \\* *
• _ :.. ?;;~_:::-,=:~"'=:-;;\\".5-*t*';-'.,;.*: ;;-..!:P:"_*: ~--~.. ~,-.-:~*,.-": * ;. * -~FS:AR analysis :of post-accident-suppression *pool temperarure.*determined..

--~ 1*~:;~;~}.t~'f~-~'.,_*~:~J;f~~:.;)~;~~~~~~:I:./~~Y.\\.a ~~~-!Jo91' ieiiiP,erahir~-of _l!pproxinlatel)<1 ~?-.°F~ ~we~ ~~ovide~.:" --.\\ -~ -~~::.-~~. ~.--.*

.~~;j!f;,~

~.:.-;->;..:-,;.~-~~":\\. {.{~~~;:;.2 ~_oq~i.Q.g-_~~t~i t9~ihe~c6~~ling.. ~9ils,.:.-.Re~ent: te-:~filysi's 'deterµllned.a :. -.

*~...-: _.. _--;~t.- :";

• .ATTACHMENT A
• ,- *.~BACKGROUND AND. SAFETY EVALUATION OF THE PROPOSED CHANGES

. teftiperature to the upper motor bearing oil cooler of 165 °F at 4 gpm. The increased.coolingwater temperature affects the cooling performance of the upper bt;:aring assembly.*

ATTACHMENT A .. \\

BACKGROUND AND SAFETY EVALUATION OF THE PROPOSED CHANGES

°F (~inus 70 °F) i.sL.16: which.is 1.6% increase from the existi~g analysis. Jhis is less than.the 40%*.design marg_in~ . Th~ p~pe support load combi~ation' for tonis long term heat up is not the ' -~ "'" '* - ~- '.*,controlled load coinbinatioh (hydfodynalnic.loads dominate). This is ., ~~-.., *_-.:: . '" _' : *l:>ecaU3eJhe pip.e' support loads qualified* to ASME servic~ -lev~l D are far ~ :~---,~~:

_ *_. ~.~greater than* the thermal loads.generated by a long term heat up of the torus*

~-.T.' ~\\::~-:.,~ *.

* * -/~~*->: *: pipillg;_:*;Therefore, *these-_supports *remfiln *qualified to UFSAR limits.

,_(~J-:;::~;;~1-~~~1:::... :~'-~.:~*~_-*.~i~~f:~;;i~~;:_~uppp~~~-~~~J~; ~~icH:hyi~~i~ami61o~ds,.~'. 2~%.-~ipe load~*. '... ' :'.;.~* *.. / ::.. ~!;/.. _.;~: :~.' ~:.. ;.~;<.\\*:*;increase' which: bounds the :ma'ximrim.(i 6%) 'theinial load increase ls-'.*...

• .*.**.* **~'.')~~i:~~f t.%(~,f t~~~~~e£.~0::;i~~Jjir;q:;;:~a\\:;:s;:;:~:-**

..,, -':~-:-.*;::~*.::-~: * --:--~-~->- ~~-,;. :.*::-r.**_-.=*,-*-*:dead weight, ~ermaI load.(at'l65.,~) and-Mark-I-hydrodynam1c loads. ~ *-; I', - ~

• ,A -{... :-)** 'o ~ *

~~-

Of--...::J' ~ * ~ - o o )

• ~

~ .... :. ';,::.::.:.,:" ;-~;.::'.~----=?.-**-.~-:..:~::.:-.,;Therefor~, the eXistil),g,torus_penetrations have adequate stress margill'to \\~* ':!',' \\, 'i. ~- .. 1..,......

• ...,~

~. ~ . :,""_.,.;;"?<-'~*-~-.,-:;: __ '.*-::.{';*,-'::*~-~- :*,.:*:~.:accommodate.the.post~LOCA thermal load ~which does nofinClude ~

• _._ '~:".-<)~~: _.:~~~-* *::-~~?* ~y;~~~~~;::~.. {C~<loffimatt(g :hydr~dyn~ic]o'ading.:: -in *'s~aD;;~the pipin'.g -syste~s are ----:

" "***r '~.. 4 ! ~ ~., ~. " \\

• ~- '-~-:::" *. :.~:*-~- ~.. *._ ~::*:.. *,;_:f:,.,;:.. :;;:d-~Withill*UFSAR allowables* fox: a postulated torus loq.g term *post~LOCA - * :.

0 - ~-.:'~~:::*?-:--;~.,~:~_.:':'~h~'.;_~'.~){*~~b,~~t.µpJ~-~180_.~f;*~*::'Pie 'maXlitui~ *caicwated'post~DBA suppressionr pool* ~ *.. * *.. f*;.

ATTACHMENT A*

BACKQROUND AND SAFETY*EVllUATiON OF.THE PROPOSED CHANGES

. Time 30 170 sec 290 sec .sec Highest..Core* P,CT:

• Spray
• . ~...

Pump.* Cavitati(in ..... ~.

• -*.~
  • .~*.

'.(..

• • • !*:'*I**.. <... *.*,.*.'*..

-*.:: *4' "'; ~-~~:'".*.* ** :~:.;~-~.~.'- ::.*:~.-.~~ : .._.... ~

• -**~~:..::*.):~

  ~~-~-

.650.. - .*9030. 51200 ~.,: _,;..;: 300 sec >600 sec Re flood .Manual 2/3 Core Action~ Heig~t Cont. cooling.* ~:., ":S;l200

S;l200

~5000. .10,000' ~1500 . 60 minutes

• S;l200

5000.-.. *.

.10,000 .I. ~1500 ,9000. -** -300 minutes Peak suppress -ion

• • -p-ool Temp.

,:S;l200 ~5000 ~)500** -* -~. .9000 Ref. Ref.28 Ref. 6 * -~~f,* 1,2

• Ref..2, 28!30 Re( 1,2

~... . *Ref< 14,_* * .J.2:-.;:,* .**~,*-* ..:.. ~:

.ATTACHMENT A .BACKGROUND AND SAFETY EVALUATION OF THE PROJ;>OSED CHANGES " *short.Term is considered the time period from initiation of the Design Basis LOCA unti~ 10 Il_linutes post accident when operator aetion is

• .credited..Jn this time.period (depending upon the accident scenario), the

-.. *containment pressure peaks ~d pressure starts to decrease. ~.. ' .-1:~1: .~-,:~~1.r*-.--.~,.,.. _~-*~.:-.-._. .:...::*~~.' .:....,.,... *..,.-,.. ~*..,'.::.""-*,:.;.'.Long term is considered the time period fromtO minutes post accident ... )rc;~-':**tS>**!

• .-:.,~,~-,.*. :.::*,.. until termhiation oft_he accident.** In thi~ time period, operator action to.. *

.. : <.. -.;.; ::<.'" i; ' *.:..... ~. ..'.;:;,<\\~spray the. containment results in containment pressure *being reduced to a' ..)... . -'* :~f::., >::':.... '\\ '..:;.. ~-. < :.: *;~:~.:.. :.~ iminimum.:: *Subseqiie.ntly, containment pre~rire_* slowly increases until the ....,'~:;.:} :~!:~:.~~---*: <::*.'. :.,.~*. ;;; *~i. ;{?~~riiaizmle~t~~at be~ng cci¢_ed _away through *use*'of tliiLPCI heat . '.-.. :>i ;~ ~ -~:-~***}; -~*: <::;- ~**t~)~~* :.*.. 7>,:;.. exchangers and;Contii.inment Cooling Service Water system equals and

• • *.*-. >---t-.:.;.-*,\\;.... ~.*':.1...... _:.-

  ..--*.,, ~*-~

~-* ~ ~ * '/**,~ ~-': 0 1;:'.~~::~. ~"~~~.. ;~ <~.: <-*: -~.. \\:*:*_.y.~-~ :then is greater.than the heat being generated. This time period is ~,!~~~,11~~J~~~['~;~~~;i~1~~:£0':~ Mi~is::,~~~~i~mj;~::: *** *. **..

• • ':.q:~-.. _.*::-,~f=T-*~;,.::~::::::-,;:-:,.. _
• ':*:~::.* <*,:.. :,:.,: "-~:**.-:*.>_:;!;':.,h*.:, __ ~ :*(95 DEG F Initial Torus and UHS Temperature

-.:- Y.- '~..c~*. ~. ~,., ~ ~.. ~ : \\_' ~,. ~-.. -* -~d.--_;.; **, ,.[. i.*. ~- j

• • ~

f ~,' ~~.: ATTACHMENT A BACKGROUND AND SAFETY EVALUATION OF THE PROPOSED CHANGES '.:.-.[... -

*-~

. r containffient*pressure of 2.9 psig arid a suppression pool temperature of i 7-2.l°F

... -. -c

ao.ur.A~oo Pool Tatpnlu'e Fe;flaee

. (BEeet ~ 95 CEG F lritial &4Pessioo Pool Terqsaiie) <:ID,,.----~------.-~-~-.,.---.----,------.,-------.--,---,---,--,-----,

• . \\... *

... - -~ :m*+-----,---,...,--,-------,--+-----~---..~---r-----,--:--------,i~--------,----;

• 1. ~ :

~7* ~:,~

• ~.*.'

(!) aD-1---~---' ____

,_**-l---"---,

... --,--_-_'*~,*~-~*~::+-'---t---'------'---*_**_*_*-+-'"'----'----.,--,,-------'l

• W-*

~c.

.: i . ;.. ~: -.. '~- "':,.. . *~' ~ -~.. -i. *** .. ~:::--- ~* i'.,' ~/ '.-.. *,*:. '":*:~Hn'+_-__..,-,----~~-----r-~-~~ .. "'°'----t--t-----~---'._.-._---+------,-,---,.--~-; ?*

.1cnm

ATTACHMENT A .. BACKGROUND AND SAJ!ETY EVALUATION OF THE PROPOSED CHANGES .

• Peak Clad Temperature: 2030°F vs. *2200°F acceptand~ criteria *.

Suppression pool Water Temperature: approximately l40°F water temperature vs.'* 170°F water temper.atlire. ~. Mainta1ning a water *i~vehit rn:.o thirds core height. is* sufficient fo iriai~tain * ':.. ~..,*,' cooling *folloWing a:tocA. '.This' core level "was reached in less than 5.. ... *.. *._* :~* './.. * ~~minutes with a conservatively ~~urned constant ECCS flow at 9000.gpm .::,~*,::::-..-:-.* * ......,.. *:;;: ':(4SQOgp.m,p~t-pirinp).'*Beyorid:S.ininµtes,.~~CCSflowrate~f15QO, *,. "1:~(1;~'~;;>\\,.::*.. i:.;.:**;~7~4~~~~:1It;z:~~~i::L~L1::~*.. P,~Sure.Of... **.*. .. :.?--:~:::'r,:.*:'.,c;< :.::' :t.'.. * :'~::. "\\.21:4 psia'(6.(*ps1g) andJ42J. pat290seconds, and.J9.8 psia (5_.l,ps1g) *.

0:1*~f r.~;*~Gt* :~,e *

,~, :,.,*~~:~ 4 ~:~~~i*~?x.r~~j) ?*}*.. *:.:'.'*:\\.. *

• .* ~- ****
• 1

~~~~::.;~,;,{:?;:::_*.. :;:':~.\\'\\."*.,.,,*.-'.:J~;i;::;c.!:A.~-~~ppro~iin~t_elY::29.9.. ~e,q~nds, :the.c9~taininent o~erpressure require~ for

-<.::* *::;-:..:~-*::*:. :: :* *.. ~'.<.-. :>.. :.*.: ::.-. ;:*'.:*.~?Core *Spray *NPSH Wilh~ach'6:7-:psig. and the**Qore.Spray *pumps will start --~~ :*;::;'--~<*~~-','~~.... <-, *: -::.. _'..:.:*:::;.. '-;~~... :itQ, cavitate; )ifhe calcuiated.minimum Core Sp~ay.floW*betWeen*290.

• f ~l']~~\\i,~,,,****,;;,~:;~~~1r~~~;f~

6~~~~t~~ii~*l~;'~~'~tmanuru. * '*:-_-;.;~2::;_::. -..- *,~~ _. * *._. <<':-**~.Th~'following;*Gor~~Spta:fflown1argms*for c9i:.e.reflooa are*therefore. ~~~ ~l~O '... '._.:*~-.-.-._-+':::;_;.~:.-.\\.::*.~*MmrinumJO~~OO gpm.. vs>1500_pgm for greater than 300 seconds

• • >..~~-:~\\~)!}{.:<--<~* -5

.:~_ '.~~{:.{.-}~I2~~t:~:~tib~~\\£.$}t~i~~h:f~~/*?:i~~~:-zil.?~=~---.. ~ _ .. _:~. .-:*.-:~;-.. :'-.>:::- ~-. ---... *- ,~ ;... "-.:~;"~~ ':f * *-;::.::,:.:,'.. --: -: _:*_ :--;:::~*~t":~.:~r::b.~g)e~*~{gr~:~te~*-ili:~:*690;$~cond5);: idequate 'NPSH.eXists to meet Co~e 1 I

• . 1--

-:-.*,**-"*' ~.:,;:;:

• • :,.. i:... '*( ** :*"A***-*-._

~ 1

• I

\\ **: '-~*, :*::~... *<'.- ...... *:: *--'."'>_,- t.*... "'$pray:p1nnpjeq)*eni~nts:art4 peiformaric~ for all pump combinations. ,: : ~ :.;, ~:::, :~::*~-:.

*.* : *.. *.. : :,.-... ~-.,,,;t,':;;~~~}ji6~~\\/~i/tliefa)ot~htjaj..eil~~fortlie: L~Ci *p~ps

-~o.; c~vltate in the 4. . *'..<\\~: *' '. ~: *-:-, :*T:?/~:~~-;/):;J>(:'.I/~~.Coie*$praf,~d~3~:ri>cu2~core Spray pump scenarios at rated <~ :.g,~:~~<-~.. c.,:_;;>:~:: ~. -:_..-:* '. >.:: _:,~~{~~;t;~'.P§b.;~~:;~,~~~~'~#:_~~~s2:@6f:!iin~~'f.:~eLy.?~ p~P.s t6 _bdo~ rated flows

* :*t*,,_:..**~'.':":'7:' ";' ~:-:,:. :*.. *. _.. ~"; ~:.-c,;~Y J;may~Qe reqwre!;l to~ e~ure.W:SHr¢qmr,~ments ¥e *met*,. Specdic cases

• i!.~~*~t~~~~ci,:'. *,;f~'~~i~~i~~~~~~f

~~~lgff &!:~~;b~l-. .:~;, ~::: *?-~;;'"::*~,~--::.'~ *,.. * -~-<~~::L.. '51~~n:ilirottimg'llie;~vit11ab1e~Lf>_ci i)uinps*;-.~:J\\.,m:iillinurrfof 9000 gpni:c4soo.. _

• '.!"~... :\\*---;-~;::_-*...,.-:... -1;;--~-:;..-.,:-- -*

-:~!*"'_-~~:_:"':.~.:.(.!~;""~.~~'~~~7*.~~,.-.::~;.*..* -;.::~,--:~;.lo*:;.:~?'::~*--.--~_k-~ ~: ,-..:...:*-:-~~--;,;'*\\......,.-:, - "~ ~ :-.:. 3.. - ~-;:;.f~t:*':':,<-~-;:.,~. :;..- *

• .:,~.~:. '~c{.?;(;r~.:.:: gp~);pe_rpiµlipi~Qrt:i $pray,flow,~s lli!swy.ed_-v~rsu~ 150,0 :gp1:11 neces_sary to

.. ~~. '.

• .:.r ATTACHMENT A'

':BACKGROUND AND SAFETY EVALUATION OF THE PROPOSED CHANGES -Other Margins. Other margins inherent in both the ECCS.perforrnance relative to PCT and

- 2/3 core.reflood: -

t r:,. .,., _.:~.,,.* 3. , __ (_:* : __ ;. _: The LPCI flowdfappn)ximateiy 20,000 gp~*is:directedtothe"*: **

• *' ';~,. ~-- * :*:: _.containment through the *break (i.e. *the unbroken loop inJectionvalve fails-: -

,~;:.:~:,. ~*:i: __ ):'.~5:.,-:_ ' <-:-to open and the brokefi. loop injection valve opens). - 'This results in.. ',, ; ::~_:*~.,"'_\\>-:; 2 .. ::\\/" !~' -/._';,:.additiOnal cooling (i.e.-lower 'coritairiinent pressure) which-would not ' ' ...:; \\ *:;*:.: -*~,,,- ::: -"*'.> ;:.-: * ~-.. *<occur for the more likely: single faihire '(Le. :the selected injectfori valve.-'_**:*> ~~- ... ; [ '\\o{'Ji~~~t';ir.~;'~~*;f +/-~;~~fai.ls 1: ~pen~ res~t~g (rt. no fl:t~the ~~ssel ~r ~~ coriminJnent.. *;.*-. ** _ **. * * ."-: -~; *.* :*:*:-.:.. -~:... :~\\;:;:*.:':;~-~'~::.~:~'::-~*o::,,.*.,'*. ~hould'the-LPCI mJe~tlon_valve fru.l to open, the flow loss m the _

• ~._.

._,_;-~~-~->-t:::: "':'. .-:J*l~-'i'~~-"-~\\~;::\\;-~_,is~ction strainers and the ring.header 'would be much loweta.e:*LPCI' --* --....

~-,;-~>J~;~~;<~?~:~~,;~-!\\)~\\;~:~t}:>_<;,:_.~~~:::~";ffiin4ll~*now-i.Il tlierange-of2ooo'io--4ooo fu,m ~8... 20,600 gpin):~: :Thi~**_,.*.-__--*

• _-:

1 ~~- .::~::c*~--~.--.. -7i:~::.o:*~-.~-~:./:;,:._'~_--::~ __ :*-~:*:'~"\\vould ~esult.ill no Core-Spray c~~itati~ri.. Additionally, higher":."

• ":~:J:t :-Of'£~;¥~¥:-:~~~;~\\::;~:~ ~J>nrainment J>'.~Ss'.i°S w~uid *~. a:~la~l°:~ * ':: '

'. * ',0--. \\.*..* \\ : ~; ;F *.**. "

• , _:_;-: *,":-;,:::;.. ::-~* :~'":~:_,_.<.:. **>-'.."**:*.:_.::-::I*......, :

.. Should the LPCI function as designed* the flow. rate to*the core:**~ 'r:**,e..:.*':-,*~:.;"*;-::~:.;'.:"~~-[L~.::=c~*,-.*....... -:** ~~ ** ~~:* ..,~*

.':.~*.'<~-~~-!'.~.;~:-y:~L... ;""_,~_.:,.~..i:.-.:.'i,*'.*:..>_ could be on* the order of 31;000.gpm; which would.re~ult in much lower._.:_~ '<< - * *

. ;~ ;:._ ' .. l: .-f" f-...c

• ..,._.:._.* j _.\\
• ,o,*-;::~~"i-'.

-.- -~

o-:~..... -, *.. ;2500 '"I

• ~**/*

--: **,'\\**:*,:.._*:-.'- ."r*. -~*..., ~,,_ £,2000 '*::::i-

'1!,1500 +. -..,.,.,:::-':'.-'1~::-:"--':'-.'+-'--,----:-+-----,---:lo..,,..=---.,.-t:-:--0,,.,-,----"--+-:-~-:--:-~:-'-.,...---i", \\... ".... *.:

• ~ -:-..

1-1'000 '.-1--

::.:,,:-.:,-;c:.r5-"7.::..-,-f-'::;;;;..,,,.~+.C:..,:--:----:-:=t-'-"--'--'-'-'+-+-::-'-C'-'-""'~-'-,-'--""-':~-j,--..-,--,--J

._.. :-::'._\\:*\\_,:{..,.*.

• *'*.~.:.

-~- 0-500 µ~~_,_.:.,::__;_-+_:__;__;:_,...l-,----""-_::,_:-+:----,~-+~--;..,:;:-:-+___,.:.,...:..___--',-+::-_;__:__,,,_:_j .. ~2 *_::'i~--

• ~.

,.. :.--.__-_*: -..*~ ; ' 0 --*r :~--,-.. -. * .<,.. o *.:--,*i:{_2~*.. :~,~-;~,;-;=-~~0':*:~:~:7;s:-.:,;*:..-1-90'.'~:-i._,:125_:-"*;_

• 2~~'.-

t;."~~-~t!.<

1. a:::;;{.&,::~*~'J:-l~;-;:.The:LpCI--heatexchanger.vendor~iliitasheetcurrently*hsts a.heat.~:,. ':.~--.* "~;:---;.'..'_,,..:. '-:~*-', --.

~ ...f,:;.*-;j.~* . :i::.J:f~"".:_,.....-,.rl.f-:-.*.,:. ~*""-*- ~ 6 ~ - ....... :::=.-_.... * ** *f- ** _.. -** -~.:- ---~ . °':"">--* *...

Z~:~'i_~:.:~'::? "transfer. rate of 105.::x"J 0.;BtU/hdn the *plant safecy analysis *for-a::2 'LPCI > -,, ' -.-.=:.. ' "-:-:-: ;:_ :~*

£~ ~~:~,;~~~~( i6;ioo;gpm)74::ccs~( oooo::gpm)i)wnp*conibination."--*:Rev:ised ancilys~s -'!.._.-_::,:*;\\~~:~~ ~~~ * -

ATTACHMENT A >BACKGROUND AND SAFETY EVALUATION OF THE PROPOSED CHANGES .. at these flow cpnditions have shown that a more appropriate heat transfer -* 6 rate is 98.6 x 1 O Btu/hr.

• .:.:~.....

.,1 *. ~ '. ATIACBME:1S'f A. BACKGROUND AND SAFETY EVALUATION OF THE PROPOSED CHANGES LIST OF REFERENCES I. DRE-97-00IODresden LPCl/Core Spray NPSH Analysis post-DBA LOCA - Long Tenn-Design Basis, Rev 0.. The purpose of this calculation is to determine if sufficient Net Positive

• Suction Head (NPSH) is ava_ilable to the Dresden LPCI and Core Spray (CS) pumps
• following a DBA-LOCA... This calculation examines NPSH condition, long.term (> 600 seconds) following the accident.

Selecting imputes to minimize NPSH margin, it was determined that adequate * .' NPSH exiSts to meet Core Spray pump requirements and performance for all pump ... combinations. However, the potential exists for the LPCI pumps to cavitate in the 412 . ;and.312 pump scenarios. For these cases; throttling of the LPCI pumps may be required

• .to ensure NPSH requirements are met. Specific cases involving throttled LPCI pumps
• : '
• were evaluated to establish the ability of the operator to throttle ihe pumps to an

. acceptable condition. Under post-LOCA pump combinations, positive NPSH margin --.. *.could be obia,inerl by throttling_ the available LPCI pumps.. *

2.

-DRE97-0012 Dresden LPCl/Core Spray NPSH Analysis Post DBA-LOCA:

Short Tenn-Design Basis/GESIL.151, Rev o..

The purpose. ofihis calculation is.to determine if ~ufficient Net Positive

• • .~*.. '. -Suction Head (NPSHf is available _to the Dresden* LPCI and Core Spray (CS) pumps
• * - * - -~-- following a DBA-LOCA.
• This calculations is limited in scope to the first 600 seco~

0

• ':followif!g* the accident, during which no credit is taken/or operator action. The LPCI.
• *and Core spray pumps will automatically inject into their respecthie unthrottled systems *

.. *-and oper~te:abovi their rated flow conditions of 5000 gpm and 4500 gpm, respectively. >:. :..' -3.* ' -*._. riRE96~0214 'Miniin~ Av~ilable CCSW Flow to MaintaiD a 20 psi 'Differential Between LPCI _and CCSW, Rev I.* *

:r~*purpose oi~his ~al~lati~n is to d~iermin~ i~ minimum av~ilable ccsw

.. : ;... Jlqw _while maintainirrg a 20 psid differentialpressure between the LPCI and CCSW sides

• ;_ :;:. /:,_of the LPCJ:*heai exchanger... *~. -"
  • For i~ DBA c~e (i.e., suppression pool o~e.;.p~essure ~et equal to 17 psigi; *

. * * ***wing.~ CCSW pump curve degraded by 15 psid (based on surveillance tes! data) results ~ *=in a 'CCSW pump flow of gpm required to maintain 20 p.sid between the LPCI and CCSW in the LPCI heat. exchanger. A CCSWpump flow of 5000 gpm provides an additional 4%

• . margin/or future surveillances..

. 4.

• GE - NE -T23000740-l Dresden Nuclear Power Station Units 2 and 3

, *'Containment Analyses-of the DBA~LOCA Based on long-term LPCl/containment ' "...., Cooling *System Configuration of Orie LPCl/Containment Cooling Pump and 2 ccsw*.. ...... * ~ *~* :J>umps.,,, *:

- -*':~ : : ".>f-' : :'The suppression po~l.tempefaiure and, ~uppression cki-;,,ber pressure '..

. *. *:* *,,.<.. ~*~-**':.'::':-~~~\\,:-;:;*'responses io the DBA-LOCA 'tire analyzed assuming the following ECCS and '. -~ ~-............., -.. -.. -". . -~ '

-~ - :

• . --...... :-~-

-... =}-* ATIACBMENT A BACKGROUND AND SAFETY EVALUATION OF THE*PROPOSED CHANGES LIST OF REFERENCES 2 LPCJ/Containment Cooling Pump and 1 core spray (CS) pump for vessel makeup, and no containment cooling up to 600 seconds following the DBA-LOCA. 1 CS pump for vessel makeup, and 1 LPCJ/Containment Cool Pump, 2 CCSW pumps for containment cooling after 600 seconds. 2 CCSW pump flow of 7000 gpm. This report also provides ihe LPCJ heat exchanger heat transfer rates, which were used in the containment cooling analyses.

A description of the containment analysis cases is provided below.

• ,*~: -.

'~.,, /* Case 1 - Nominal pump flow rate - Nominal containment initial*conditions Case 'JA - Nominal pump flow rate -.Containment initial conditions to . minimize containment pressure.

• .
• Case 2.-Above nominal flow rate for LPCI/containment cooling pump and CS

. for first 10 minutes and nominal pump flow rate after 10 minutes - nominal containment _. *~/ **': ;:-

• .*.... ~'..--'* -:
• ~- *-
• initial conditions. *

~-...... ~~-*. -- ~: ,. :~*<*

• Ca5e 2a -Above nominal pump flow rate for LPCI containment cooling pump

.;~:- ' *_,.... *..... o.,mJ* CS for first. 1 O.minutes and nominai pump flow rate after 10 minutes - containment

~*:. _t initialconditions'to minimize containment Case'2al -Above nominal pump flow rate for LPCI/Containment Cooling . Pump" and CS/or first 10 minutes and nominal pump flow rate after.10 minutes - .: containment:initial conditions to minimize containment pressure, drywell and torus shell hat*sinks modeled.. * ~-

• ~,< ~;. *-
• . '.
• _**. :o*Case 3:,. Abo1'e nominal pump flow rate - nominal containment initial

>*~ * -" _.;.--.. ~- *>*.".conlii1ion5:. * ::

-~*.:. *. ;.

• -;7*:..:

..~

~ *.;-'* **\\*-*~'-

• *:....... J--:.f.! *

~-

• • ' -.: ~-~.. *: * *:.,~ **

~* * '::i;<,, ** < . Case~ 3cr-Ab~e nominal pump flow rate - containment initial conditions to -~.:.minimize containment.pressure. .;:*..... <-~ . ~

* *.** -., l 0

• Case 3al -Above nominal pump flow rat~ - containment initia/conditioru to.

.... *. minimize containm.ent pressure, drywell and torus shell heat sinks motJeled. '~ I 0 ". "5;~ . *.: GE Letter, Dresden Containment Analyses for Limiting DBA-LOCA, dated

• • • ,;;~t~*1t~~z~l:2,1is.;*.. **~*. "t~~~\\!:~~~~,:s~~~~~.~~~~=~

~: 5400 ...... -',.:;.:..,... ::<:!,:~.::-,!". -,.-;,.. _ -.-. * ;_;, * *.:.. :.. *...' *., Th,e~suppressionpool temperature and suppression chamber pressure "'*,.. ',;~l;.C.:':::*~~;~;:t;;~c:;:. ~";'~/~?'. -:.. :\\:.responses tdt he DBA;.LOCA assuming thefollo;.,ing ECCS and containment cooling. r* AttaclunentA. ListofRd'~enc:es L.,,

---t ATTACHMENT A BACKGROUND AND SAFETY EVALUATION OF THE PROPOSED CHANGES LIST OF REFERENCES ~. '.. :" ~ 2 LPCJ/Containm~nt Cooling Pump and I core spray-(CS) pump up to 600 seconds following the DBA-LOCA. 1 LPCUContainment Cooling Pump, 2 CCSW pumps and 1 CS pump after 600 seconds. 2 CCSW.pump flow rate of 5400. A description of the containment analysis cases isprovidetJ.below. .Case 4 -Above nominal flow rate for LPCUContainment Cooling.Pump and .CS for first JO minutes and Nominal Pump Flow Rate after 10 minutes - Nominal

• Containment. Initial Conditions.
• . (). *

.. *

• GE Letter, Dresden Containment Analyses for Limiting DBA-LOCA, dated Pecember 26, 1996, DRF-T23-00740, Attachritent A Containment Pressure and
• . * : *: *TemPerature Analysis for Dresden NPSH Evaluations - 2 CCSW Pump Flow of 5000
  • . *** gpm.

.\\. ** .. _."2 LPCUContainment Cooling Pump a~d I core spray (CS) pu"1p up to -600 ~-:.

• ., :-. *,.. *' ;.seconds following theDBA-LOCA. *

~ <'...:.-::.-

** -~-:\\.:~*:'-:-, -. :

• __.;*.. ~.. :

-~

~ _/. -

. *

.-~*:* :*<.*,,: **.. *.... ) LPCUC~ntainment Cooling Pump, 2 CCSWpumps and I CS pump after. . : >".'.,~; '*600 sec~nds.. :.'.*.:. ~-..

• • • .::~

':~:~.*... ~~-----*~ ~

. :.~~~-~**:-:*..-

... *~: : ~-- *.... *':itcsw pump flow rate of 5000. -. -~-~... . A description of ihe containment analysis cases is provided below.

• .,(

~ *-.. Case'S-Above nominal flow rate for LPCUContainment Cooling Pump and . - CS for first JO.minutes and Nominal Pump Flow Rate.after JO minutes-.Nominal .Containment Initial Conditions.

• • ,;;~ ;

'*._._.:(_\\~~; :"; ::D: :. 'C~~- S~* -Abcive nomi~I pumpflow rate for LPCUContainment Cooling. '.. '.. *.'. *',.,_:. ~-:.::.-::.:,Pump* and CS/or ft~st JO minutes and Nominal Pump Flow Rate after JO minutes - r** ~~.. :. ~2L::

~.\\ -,

..... '- -<~ ":...

• ** *.*,*.:'?:':Containment Initial Conditions to Minimize Containment Pressure.

~-"**..'.. -**

• ~*

~ ~* ~~-~*"" Anachment A: Lisi oflleferenca -. ... ~* 0

.,r . -~.* ~ - ..L. ,_*';""',.,__.I.. *-*,/ . :... : (... '-~~. *.. ***.....

• \\..

~ ,}..

~ -~..

AITACUMENT A BACKGROUND AND SAFETY EVALUATION OF THE PROPOSED CHANGES LIST OF REFERENCES

7. -

"Cavitation Test Report for Bingham 12 x 14 x 14 x 1/2 CVDS Pump, Bmgham Pump Company, May22, 1969." Provides results of pump cavitation test. No pump damage was observed after testing.

8.

NED0-30832 - Elimination of Limit on-BWR Suppression Pool Temperature for SRV Discharge with Quenchers dated December 1984. (proprietary); NED0-30832A May 1995 (proprietary) NED0-30832 presented a discussion oftest data and analysis that supports -deletion of the requiremeni to maintain the local suppression pool temperature 20" F _be/Ow the saturation temperature ofthepool during SRV discharge. -

9.

"NEDO~l0320 -The GE Pressure Suppression Containment System Analytical - -

Model dated April 1971. (proprietary); NED0-10320 supplement 1May1971.

(proprietary); NED(}:l0320 supplement 2-January 1973. (proprietary) - Provides a description of a coupled reactor pr"essure vessel and containmeni

• -- -model wed in SHEX -

IO: _ - NED0-20533 - The General Electric Mark III Pressure Suppression Containment-System Analytieal Model chlted June 1974. (proprietary); NED0-20533 - ~upplement I.September 1995. (proprietary) _

• _ -Pravides a description* of a coupled reactor pressure vessel and containment_

model u.Sed in 'SHEX -

11. :

-GENE-637-042-1193 - Dresden Nuclear Power Station Units 2 and:3 *

• containme~t Analyses of the DBA-LOCA to Update the Design Basis for the LPCl/Containment Cooling System FebTUID)' 1994. _

.-1 .This reporl p;~id~ a b~nchmark analysis to validate the SHEXfor app~ication to.Dresden Station: -- --

12.

_NED0-2105i-Maximum Discharge Rate of Liquid-Vapor Mixtures from Vessels date September 1975. (proprietary); NED0-21052 supplement:A May 1979. -(proprietary) _ .. Describes.GE co;,,p_uter Model SHEX-04.

• .-*7 13.-.

GENE-770-26-1 o9i-Dresden Nuclear Power Station Units 2 and 3 ._LPCl/Contalruneiii Cooling System Evaluation dated November 1992. _ 14. -~- Letter S. Mintz(GE) to J. Nash (GE) DRF-1'23-00740, Dresden' Containment ,.,___:~:~f\\~?j-_::-~t:* -::--.~ :-~ ~: * - '-.:.::: __ :.:._,Analyses for _ComEd NPSH Evaluations Transmittal of Digitized Suppression Pool ,_,c,~:_~:\\:,;**-*.~/-~*'?:_)::,:;*,_: - - _ ,_'/Tem~~~~-*aildSuppress_ion ShamberJ>ressur~ Time Hi~tofies: -.-- -_.-._- ~ ** .,_,....,;.*.;.._..::.;~*:..,..*7~:..... ~"~ *. ~. .* --*.:* \\ ;.-,-*... *._*., . :*:~~.:,'*,~:;:*:.I

• ::-1

. ~-- '}..

A'ITACBMENT A BACKGROUND AND SAFETY EVALUATION OF THE PROPOSED CHANGES LIST OF REFERENCES Provides time histories In tabular form for Case 2al - 20% mixing (Reference

4) and Case 6a2 - 60% mixing (Reference 19).

15.

NEDE-30911 - SHEX User Manual dated August 1985. (proprietary); NEDE-30911-1June1994. (proprietary) Provides benchmark analysis to validate the SHEX code for application to Dresden.

16.

• Deleted.

17.

Deleted~ 18." J. Stephen Perry letter to US, NRC, dated January 13, 1997. Dresden Nuclear Power Station Units 2 and. 3, Emergency Application for Amendment to Facility . Operating Licenses DPR-19 and DPR-25, Amendment to Resolve Issues Related to ECCS Suction Strainer Pressure Drop. Emergency License Amendment Request Technical Specification changes to

• lower initia( :

.. suppression pool temperature and CCSW.inlet water temperature and take credit for.2 psig over *pressure.

19...,.

• GE Letter, Dresden Containment Analyses for L~iting Short Term LOCA Event, datedianuary 28,'1997-TRF-123-00740, Attachment A, Containment Pressure and Temperature Analysis for Dresden NPSH Evaluations.'
• The short terin (600 seconds) suppression pool temperature and suppression
• chamber pressure responses to the DBA-LOCA are provided assuming the following.

ECCS and containment cooling configuration:. 4 LPCUContainment Cooling pump flow of 5 I 50 gpm per pump. 2 CS pump flow of 5800_gpm per pump. *

• A.description of the containment analysis case is provided below:

.., * * :,:_~. Case 601 - above nominal flow rates and JOO% thermal mixing

• _Case 6a2.-:-.above nomin0/flow rates and60% thermal mixing
• 20.:
• .GE-NE~TS2300740.:.2, lliesden Nuclear Power Station Units 2 and 3
• containment Analysjs ofDBA-LOCA Based on Long-Term LPCl/Containment Cooling
• system Configuration of One LPCl/Containment Cooling System Pumps and 2 CCSW Punlps - Additioniil. Sensitivity Analysis.

. Various ~ensitivity cases were analysed/or different l~ng-term pump

• "flow conjig,Jrations. The pump flow configurations during the short term (up to 600
  • seconds) is the same in all cases -2.LPCUContainment Cooling Pumps (10600 gpm) and

. Jcotesprdy_pump (5800.gpm). ~ .,{'LPCUContainment Cooling Pump (5000 gpm},. 2 CCSW pumps (looo gpm) and I CS

• -~.* _:-. _.pump (45D_O gpm} after JO mi~tes. 0% "thermal mixing efficiency of break liquid
• . ;.--_.2,* ='=-Containment cooling initiated at 10 minuies. * -.,. *.:
• _

~~~:.. ::.. ~*.*.. '::;~.. ~<-......... .t:~*-:.

• .~ :.**.::,\\. :..- ; ~~**,_**
• _' :., : * ~ttachment A:" Lisq>f References **

.:.. **.i*

ATTf"CBMENT A BACKGROUND AND SAFETY EVALUATION OF THE PROPOSED CHANGES .. ~:. 't_,*' LIST OF REFERENCES 1 LPCJ!Containment Cooling Pump (5000 gpm), 2 CCSWpumps (5400 gpm) and 1 CS pump (4500 gpm) after JO minutes. 0% thermal mixing efficiency of break liquid Containment cooling initiated a.t 10 minutes. CaseS-3a 1 LPCUContainment Cooling Pump (5000 gpm), 2 CCSW pumps (7000 gpmO and 1 CS pump (4500 gpm) after 30 minutes. 20% thermal mixing efficiency of break liquid. Containment cooling initiated at 30 minutes. CaseS-3b 1 LPCUContainment Cooling Pump (5000 gpm}, 2 CCSW pumps (7000 gpm) ~nd 1 CS. pump (4500 gpmO {ifter 30 minutes. JOO% thermal mixing efficiency of break liquid Containment cooling initiated at 30 minutes. CaseS-4a 1 LPCUContainmentCooling Pump (4611 gpm), 2 CCSW pumps (5400 gpm) and 1 CS pump (4500 gpm) after JO minutes. 20% thermal mixing efficiency of break liquid.. . Containment cooling initiated at 10 minutes. ' CaseS-4b 1 LPCJ/Containment Cooling Pump (4611 gpm), 2 CCSW pumps (5400 gpm) and I CS pump after 30 minutes.. 20% thermal mixing efficiency of break liquid Containment

• cooling initiated at 30 minutes.

CaseS-5.* J.LPCUConiainment Cooling Pump (5000 gpm); 2 CCSW pumps (5400 gpm) and 1 CS.

• pump ( 4500 gpm) after 30 minutes. -.io% thermal mixing efficiency of break liquid*

Containment cooling initiated at 30 minutes.. CaseS-6 1 LPCUCoTJtainment Cooling Pump (5000 gpm), 2 CCSW pumps (5400 gpm) and 1 CS .pump after JO minutes. 20% thermal mixing efficiency of break liquid Containment cooling initiated at 10 minutes. ANS 5. 1-1979 decay heat will be used with a I.1.. multiplier on decay*heat. Appendix B to this document describes the methodo/Ogy utiliZed to calculate heat exchan_ger performance parameter Kin Reference 4,

• 5, 6, 19, and 20.

21.

J. Stephen Perry letter to U.S. NRC,.dated January 17, 1997; Additional - *Information Regarding ~endment to Resolve Issues Related to ECCS Suction Strainer . Press\\ire Drop. * ' ~.. 1~~~~111~~~~~0~,;&.,d~~:;:,;.~,~,~;'.,~~'~ ~~* .~* . *-~_::-,. ~.. ~ --. *~. ~..

• • ~,*

ATIACHMENT A BACKGROUND AND SAFETY EVALUATION OF THE PROPOSEQ CHANGES ~ LIST OF REFERENCES Provided to the NRC the NPSH calculations to support the Emergency License Amendment (Reference 18) and response to NRC questions.

22.

J. Stephen Perry letter to U.S. NRC, dated January 22, 1997; Supplemental Information Regarding Amendment to Resolve Issues Related to ECCS Suction Strainer Pressure Drop.

23.

J. Stang (U.S. NRC) letter to I. Johnson (ComEd), dated January 28; 1997; NRC

• Staff Safety Evaluation Report (SER) Approving CoinEd's Proposed License Amendment as Doctimented in References ( 18), (21) and (22).

NRC Safety Evaluation Report accepting Technical Specification changes and design bases changes in Reference 18, 21, and 22.

24.

• J. Nash (GE) letter to R. Freeman (ComEd), dated January 27, 1997; GE Nuclear

Energy (GENE) Use of"SHEX" Computer Code.

. Provides a discussion of the application of the SHEX code to perform

• * *
• conti:linmeni pressure and temperature response following a Loss of Coolant Accident. *

25.

• . -GE Docliment 384HA497, Heat'Exchanger (RHR), Heat Transfer Calculation

... Computer Program." Oct. 1979. (proprietary) -

• • 26~.

.'Letter, S.'Mintz to S.L.Eldridge/B.M. Vlehl; "Dresde~*LPCl/Containment ,: Cooling System:. Comparison of Heat Exchanger Heat Transfer Rates," Dec; 28, 1992. * . Pro~ides notific~tion to ComEd, of the reconstituted heat transfer rate of 98. 6 x _- uf Mbtulhr . 21: "Deleted. 28.. - ".NFS:BSA:96-l38,.AcceptanceReview of Supplement 4 to ANF-88-191,' 'Acceptance Review of S\\lpplement 4 to ANF-88-191. .:* ANF-8B-191 Suppl~ment4 calc~i~tedaPeak Clad Temperatu~e (PCT) of . 203,0°F:with a Core Spray flow of 11,300 gpm (5650 per pump) with increased Cote Spray water temperature and leakage. *

29. *:, NFS:BSA:97-009, Acceptance Review of Supplement 5 to ANF-88-191, January 22, 19.97.

• .. **. *:. * :, ANF-88-191,. Supplement 5, calculated a Peak Clad Temperature (PCT) of. *
• 2163°F with a reduced Core Spray runoutjlo..;_, of 10,552 gpm (5276 gpm per pump).

.. ::~

'f- ~ r* AITACBMENT A. BACKGROUND AND SAFETY EVALUATION OF THE PROPOSED CHANGES ~ I LIST OF REFERENCES b) With an assumed constant Core Spray of9000 gpm.a time to rejlood to 213 core height was calculated to be less thanfrve minutes. c) Beyond frve minutes an ECCS flow rate of 1500 gpm is sufficient to remove decay heat and maintain 213 of the core height. .31. Letter R. Muralidharan (GE) to K. Ramsden (ComEd), Long Term Cooling of

• Reactor Cores of the Dresden and Quad Cities Nuclear Plants following Postulated

. Design Basis Accidents (OBA), February 12, 1993. This /etterprovides GEassessment that the Dresden core wil/ stay cooled over the long term, following a postU/ated DBA, as long as the reactor pressure vessel level is _ maintained at least as high as two-thirds core height which would be the case for either core spray or coolant injection.

32.

• Letter S. Mintz to J. Nash, revi~w ofNRC Information Notice 96~39 February 7, J997;*.

.Adequcity of decaypo-.i.ier values used in the Dresden containment evaluation in

. support of an update-to the Dreiden UFSAR containment ana.lysis b'asis is addressed in ,*respome to NRC Information Notice 96-39. 'The GENE decaypower values used the the . ~Dresden containmentevaluatio~are based.on a nominal applicaiton of the 1979 ANS * .5._l decay heat stanc/Ord. -'.~ <: -. *** -'33*. ' *:Letter, S. Mintz to J. Nash, "Dresden Containment Analyses for.ComEd NPSH

• * * *"* - Evaiuatlons; Transmittal of Digitized Suppression Pool Temperature and Suppression

'~ ' Chamber Pressure Tinle Histories," February.5, 1997.. * . * -. -': Provid~ digitized time histories of ~uppression pool. temperature and suppression cha"!_berpressurejor C:a.se 2a,l with 100% thermal mixing in Reference 4. ~ -~ - . -. ~-:. -

• ~ *:**-. _--

~, _... ~ .*.i-,' .. _,_-~. ' :.

.~..:. ~ I AUACUMENT'B * '. .*y;'.

• NO SIGNIFICANT IIAzARDS EVALUATION
• . *,_.-* The' C~Iluniss*i*on haS provided standards for determining whether a no significant haz.ards

-. * :. *:*consideration exists as stated in 1 OCFRS0.92( c )... A proposed amendment' to an operating *

• . *.... :< -:..., '*... Iicen8e' involves*. no sigriific~t.hawds consideration if operation of the facility in
• .. ::;.:<~:\\ :. -~:;:./.accordaiice ~th tile pi::oposedamendnleiit W:ollld not:. (1) involve a significant increase in
• . *,'.}o:_.~:\\.~h~;':.~-'>~~:?the.:pro~abilitY or c~iiSeque.nces ~fan a~cident prevfou5ly evaluated; or (2) create the *.

~*...*

• <~:<:;c;;~ ~.:.;:;:: :: *possibilitY-ofa.liew or different kiiid pf acCideiit from any.;accident.previo'usly,.eyaluated;.

~t'~~:;;~;t~i.;t~;~~j~;;ir~;.*i.~~°jt~~~t 0 ~.*nm:~ :r.~~:, * ********* * *

• .: "~::.*----<;:::-~,~.~~:i:<"~; ~ConiEQ.pr~P,Oses to*8:ffie~.a)*acilify -Operating* Licen5es. DPR..:19. and DPR-25, AppeJ;iqix.

I

• . ~~: ~~:.: -~~~-:;:.fl~j/=;_;;~;*~;.J.e~_!micaJ.: ~peClfication5;"f~r Dr~~µen Units '2*.and 3... ;rhe~ proposed amendment * *.., ~--. *
• - :~:7>iF.7~~.Jiiif;S:;:;~~Tr~qu~~i~hangeS.-'.{echllicaI:Spec_ificatfons*(TS) t7J( "Suppr~ssioQ. Chlunber," and ts*:.*. ~-. *

~**~:~~~}~;~J~§f/~J~~t~{)S~-~q:;;:~~~~at~}i~~~is~t:*~d.~e:.!e~bni¢at.. spe~ill~atio~B~es,*~o-ieflect ~evis~d * :***~*--:. *. * --.,~*-* --~

. *. :::::*,;~; :_:, ".'.~;::li6t~:~:f0":!.3nijYses ~~- suppo,_rt;effofti; to. ~ec<?ns!ifute. f.!ie design :~asis* of OreS!deri' s co.ntainment~ *.. *. * ~.

~;#t

~-~<=-;:~S~~f~~~*'*~heat:rellioval:systeili_(CHRS)~'l~lant operating_parameters *aie*being'revised fo reflect the

~,:* *

-'. <f~~ Y:..rn~~:,~:';~~Ji~fe~fu&.~icoiriEd ~~~ ~fl~rts':.t() ~~constitUte.'the design' basis of t);le. CHRS for Dresden-._.:.,,*... :....... ; :.~! ~~;~~~,~tt1~;f j:~&1s:f ~~i~~;~~?~k';;;a~:~t,:~_: ~> :~,;~_,:-.. ;::;,,;:~ : > ;.

• 0 >~: ;~~~~~1~~~~\\;v_tQi~p~qp9~6a-iic~~e1arneh¥.~~i:a~es ~~~i' reflect"a-~h~ge*to iliJ physi(!ru design,, or' the"

~-. _* :. :.:.** ;*.::~... ~~. } ]~ii~~~~i*'1~~~~}1~t~t~1~i~31ci~fi~,~~f~i*.~'.~f,;~;:~:,~- i':~:,~; ; ; ;: :* *,_:'.: ': :_ ';:.;. ;.;,:0*.:. -~r* .,~~:::~.~~.:~:& ~~'9fihe'ke~~el~m~n~qf.:fue'.pf9posed lic~~e:ajiien~e~t-req~e.st*~e as*~,:._;.**.. *;........ :*:~*, '* *-~,-*,~... ;-_ f~,~1r;f1f~fl~~~T6ltl'\\Wfi~if~}~~~~~7@j~~~;1;t;X$~c~~~~~~:~:~,;;~:~'<';S~"ftJ'~ _.;;;;,;;.*.-.o...;:,'.f."~'""'*r.~* ;..0?-J;!;;';.;.s 0 .. *,.12.:AS:a result.of. the des1g~1*.bas15*reconstitution efforts. for~the.CHRS, to mamtaui *,,. *.

5'1!i{°{?~f£~[{~~~1~~~~~~~!~Je~~~

~w:.~~-~:~'.#~~.~y~~~;in~ ~t~ ~e_st9f~~~~~~pa~~l~fy-..t6' operate:~e) ':~;.. * --~ \\-i-:,**~\\l j> *.'.

'~'.;..:.':*fi~~.£--i~~{:~.. ~tf"i'::-~0~4~*..;Ja~iJ.tty:dl.,lllilg Jh~ :~armer_µi~ntl\\S. o_f tlie *year,.*th_e iµ~upi-allo~~ble_ Technical*.t*... _.., 1 * ~-*. '.~~~:1~t~'.~~~~~wi:t;;;;.'~'.'~~]?~si)edt1~iilin \\ya,.tefij~D!P.~fcit1lfes,(qftl1e*.ccsw'µnet (Ultima~e--iieat*sllik). and the.:-.~-~ -_:-".:.-. *

~*,~;* :.::.

,~~1,; ~~~itl!~~~~~t.f

~t~t~~~;r~~;p~f§~~~~:;~;;q~*i:.:~'~;:,,,*

[Jf~~W~;ff ~!~~.. _ ~i~tli'.¥.:~r1;~7;s~;~H!~~t~i~~1.~i*~.~~;~ii~i@~g~:~-~#~n~§~ ~6-t.:.~~~~~ol\\"~~9)~-:;.~~ti,0~?*~ ~.:.,.:_~ -~.::*. * !:*.':\\:,:~ ;>.&... :_ ,~::_:;~;;;:;':~~:_;~:'SJ:@~~,~.,;j~};'C:~;:ahd:~µr,ve1llanqe'Reqwremeil~ *(Sl_l).'ate *effecteq;..,.;Clianges.jo the: Llc~nse Conditions

• ~ *.:.

~:.~4-;....;~!:'-... !:.:.~.:-~~;,.:_~*... ":,;..*~:::::;.:r... ;T.>:.._1-.":.:*;-;-._;:.:~.*.i-1':~x.

..-! *.-**.:.::;* -:1.:..r.. ~--.:*..,,:;... :.;,:.-2.,'~t... ~';:' *

• ~*... - 1.*. *.

.. :':.*--*~ ;-*.-.. __ :.. ~----

--~ .>-*;r.~_,- f:."*O"i.c~~"*'-i:~<"'.;'.'.£".::';j~,;.;;i;;\\,~J;C,...present*uifaCillfy:'.QP.eratmg Llcen5es*'DPR-'J9.and DPR-25*'Llcense Conditions:~* ; ~-:Z_-~~~~.;*;;*~~~:-}:?~:~~*~~~~-t~~::~:.~~!-~~ -:;~: *:... : ~* *' :;:.

~:1-.*;. ;~.:7::::; :,.' :~.-; *. ::-.:*... ~'.-.. :';:...:-~... <* -<... ~*.:*. -*~*.;.. **~

", '.. _.,. - ~:': __ ~~:~*

f \\ ~- ~-::. :.'*~-~ /_: / ,,:.;*>> :.:;;/.. :;;,~c~.'1~t-:,:j*- ;-.:~ :;.--;..;>.... 2':C(6) and-3; 0; respecti.y~ly~.. are :also proposed Jo support the r~v1sed analytical~..-** , -:.,_ *<:.. ~. *. <'- *.

~1

:~.~~~>-,,*"

,'if *., ~~:-;JiP.Q~!,LOQ:A**:c9_~pi,tJ.~ns;as* 1}y~ll, as I~d.uce4:IJ_HS~~,4 Supp~~s.s1~~ Pool average wat~r :;,.. '.*~.. 0

• ., *.~~"':*'- ~**'.;.*

,..~.

• \\. ;_

. :AITACBMENT*B .. :. ~--<.; _:-: ** J ~ _;,.' *. - : ~. *. ._.. ~ 'NO_ SIGNIFICANT HAZARDS EV..U,UATION;_ ~:. ,..... '~...si>e~ificatioiis: and require acceptance of11ew analysis methods to support these . -. _. determinations, the revised determ~ations resul~ in an Urireviewed Safety Question.. .... : :;.. *'.: <* .i:'.~.:~:~lg~~r :~c~at~~f~e~ suppr~s~fci~ pobl tem~er~tures, due t~ ~eduction~ ill' th~ : "*~-:... *

• (,-c ;;;

  *::::.;~CCSW flow rates and LPCl/CCSW heat exchanger perforffiance, are anotherresult of*

~, :.*.. :*:.:;~*~:~~(:~~;.'I~:i'f:;~:}:ih~;reco~ti~ted ~esigr1~b~~~Ior ilie*ccsw sy~em._, _Ne~ _design.basis vaiues 'for *..

• .. ;**;:'~-c:~:r*:::::'.~-._.-~:t'/:.~:'.*\\cCSW*flow*:ratesand.fortheLPCl/CCSWheat*exchanger*areestablishedwhich*are*

~~;~;i.,f.;*'*};j/i.. ~~~~\\::,)~:;;;{t~~~+~~~:terijperatures,support,the"basis for:.~erechriica1 Specifications for: those systems, the.-::..,.. i~~~J?~~¥~f 3ii:~~~~~;~S~.~,~~~3~,~~ecy ~~~~~:,,.... *.*, > *: *. ~,>' *... '.. *... :.. * . ~~*:;~:":"~:~;iii~~':I;~.i~;:,~.:Qq~~~!i~:ev~uate~*the'pr~posed_~~<?ense ?\\m_en~ent arid determine4 that ba5ed on.*.:-........

,~~_::{~~:.,-!;;~~.t3<~~:;~{::~!Iie.-:~tjt~#~.'for *:~~~g a_ ~igruti~aiit'iiai.atds... co~i~ex:aiiol}-esti~lis~ed-:i_n* 10. 9f<R.-?0:9.2,: - :-~:"::.*

• ~

'*~....,._~"'""'.... *::!>*.. l'**~--~ "'".! ~ ~.........

• --*~~--> *'1;

_,\\.'. -?i;~:)'.}~~rt;:,,J9peratioif, of. D.fes4~irU~ts :2* and.'3 ;*in* a~cordance. With the _pr9pose<i; ?ffi~ndnient will.not:.. -* :_ --~~"- .. J::.~1(f}t~~=1:~i~t~~Th'.~~~~~~r.:;~~;~~~~i~~~;~t:~~~~~;Wi~;~1~:;~~;:~:~:'-;~';_1-'.:~<<~1~-:,~::;;-\\:.:_..,.~, _ >:-: ~ :::_.-.-.'::::*;;;~: :~.:;:;:::i*~.::_:-.,J; "

-,~=-': ~~;:~':-!.. ~::~-~-i\\.~;:~:-kl)~i'.:~~.t"IP.v.~lv.~ ~)iID1ificanf increase~m the pro~abilify_ or cons~quences of an :* *-:_., ;-<--.:-,.,-

4 ,4.~ ~-*\\;.-- ~ .- ~ r:) ' * *- -.J '.... ~

• 1

-~-"'~:_..._:1.{::;:;;-:>1"\\.;: -~~;~~-*~~~'"'.{::_accident previousl.Y eyahiated because of the following:.. 1%~~1~,~~~~!lWi~'.filf~r~1~ftt'~ti~~;*ti~ii'~i:.,~-~:;~-!l~se~~~¥~~ ** ***

*+~:~~:;:~r:*:~;~'.~2~!:1:du:::-peifqm;i~Q )!Sing-:r:eVi~e~. valu.¢5.fof ¢ertail{ system. and-eqUipmerit penormaric_e parameters *'

'-,.. *-t -*.

• -~"

...... !~'(..>..'!' ' '.'.f,.j{- °'-?- ...,°';._ ( *,_ 1 ~ * -l..1-I~-' ~

i\\~~f:.~~'.:i.It~L~'.~;,t;~~~)hat#i~re*~~c~teiy!eflect:.the-:Dre~qei1:.Sui~on design.~The.changes restore opeiCJ.ting_....

}~~~~~;~i~£1:~X~1~\\;}i:!ii~tii~~~, ~(lJlt~~i~:~~-ar§pi~(~~ ;:S.~ppr.ess1~n:~~~~ -~v~~~ge. wate!~ temperature*_._. _ -::~ * :. ~

~;:,~~?:~~~Y:.J.~~~.. f~t;:::*~~O.ris!ste_ritwith':thej(desigiiarid'~liiclf.Will_.perri:µt operatiqn* o~ ~eJacilicy diirillg th~. '*._. -...,.....

1*~-:*5"_.:.:.""'--:.';::r-.=-=*-~:::i..-

.

::.::'"'...:.~-.

.~-~.-,.. __ -~:* ""."':""}*:.,~-Ho *..,....-!,.""!..

_:..,_.~ ~... :oi.. _*',}::\\:;,Jf.:.-~. -":"...

• .,' ~

h...

.~'°!*_:*:~~;~~~::.-,"~ *:-:,~L~!..~~warnier~ontlis*:~f.the y~_ar.:7J:h~ pro1>9s~q.ch~ges-directly effect the nµtial conditions:<-.:~ *... * *

~~;*~~,.f~~Jf.;:J~~~/~: >~~:~s;:~asS-4fileCi;ll!;th~*ii{f et)'. a.i!~Y'~e{f~i tlie'.l>l~t~,howe*ve~. riew alla1yses aeffionstniie that. the ; * * -~;.:~~1~~\\;*:~?:~f.;::':}>:;i~ility\\\\'.ilt~o~~ue-:tc>>.resp~n~~.in.,a;m~~ic~~istent witli the eXisti~g safecy-~yses. * :-:---. *: _ *-. S};~?i~;J;~;~;1*~;?~* };;:)~e~~!h91i~~.f gr:<ielrtoii~tratiiig ~e .. aae&Wi~f <?(the-existin_g ~esigii' are pr6posed.for . _ -... c. -~: r*-"'~*,.t.'J... *.r,:l:.**~..... ":."',**-.-~<.;,..,~ ,._***.. ;,*1 ** *";.<.:-"\\-"'*f~.i., .. ;j.--::f:,t'c*~'"-l.'"*-"*--.-...*-*._,.,,

• ~-~'>

-.>\\,,,l.~ \\ <l l

.~~-

:.*-¥,-;;:.;-'1.

0*~~{ ::.::;;:1~~:::-;Jcfuiilge.:and'the amendriient aetails~the bas1s:'for acceptance of.the new:methods*and.'.. '..

• t~~~~f~);'f P~j"~~~~~i~l~~~~j~~f~,~:~~'J ~ti~;,'...',i,.. :~*.:;y< *** * *

~ :c ":...*. *. **.. * >.. ** ~'i~'.~~~~-*>o"':;:~J ~:f~£7-~;;5~... -o_;~~l?.,¥.ti-Y.~:.physi~~~;~lia:rfges"~io'.itie,"faciI.~tY-:ar~:pfqposed. -~-The. plant _Will c~ntinue fo.' '*:.:*::. -~ { ::.

~ ~

.:.:

,*. L I. ~- / _ ATIACBMENT B *

• NO SiGNIFICANT HAZARDS EVALUATION-.

. *_ * *. *... *.Tue proposed c~anges do not effect systems which ~e contribufors to hutiating eventS for .,... i; : *-previously eyaluated accidents and therefore, the probability 'of any ~ccident previously

• • *. **. :*-', _:. :. : *eval~ie~ is not increased by the_ proposed amendment. *. *. : :,.

. _.:*:,. __.*....... _--:~:.~.:*.'.;~~:.*:;:..,... ~ . -~--... *. .. **:.~****.

• -*-~*-*'.... -,.:**..,.

.. :,**::: *'ly.-.. :*c~~~1te-the possibility of.a new: or different hlnd of accident from.any*,, /:_~: ~ :\\/.. _. (.. ;.. -: ***~ccident previously ~valuated hecause.:

• _ * : * *.. ~
• _.-.,.,

~... _ :**, *. .... :-;.;*::*:<~*~<'.:. ~:/-~ -<~--: :~*: :-- ~-.... *.: *" <:*:_~;*>r---*:.:--... :**.. * *,._.. **,.i, _ _",*::: ~- --~- -..:-.. ::, ;~;' 1/.;'_-:::-.';.::-*The pr:opc:ised Hc~1,1Se amendmenffor Dresden-Station does not create' the*possibilify of a

• ;}.T<~~;~~:>?~'.-~/~'.:>!iew;or:different kind-ofaccideiit.thanprevioilsly.eva!uated_.forJ)fes~en Station, The **.. * -- *. **

-~* ::*~~E:.1~:};\\d>.:i?.. proposed *changes merely-present-'anci mcorporale-the results of rie~ anatyses which:.'.**.. J21tQ.~~ii~~"-~:::.,,u::~~;~:~iif:~ff t~~i.di~:";~~:~\\Z~ut6::iiy":~::d~ 0 of < *... -* * -~~ ';":~_.7{~; 1

..~::c~:_..~'~\\qperation_have.been'identified or are intr~d~ced_'bytlie:prop'c)sed changes...The.~hanges

~ _*...

• ~ -*'

$......,.~ ' _.:*:~~:Z/:-.:.~;::i~,~~~:-,.;~,::::to*plant*procequies whi~h 'ate reqlliied t~ sqpport the*proposed_ change_are _con~istent with -*~. ... ~ ~

• .\\

~ r * ~ * ~ '.. *.. : ~ ~ *... ~-** '."*~;:.,. ~* *. ~ - ,:-:'.**w* _:r*,:*_:. ):*;~:;:~;i;;:~;~... ~;i:::**~'..'-dete~ation_QfJl~~*pr~s~urtf(~hich would'~e*expected, ~well* as the use of,,*, *:.*_ ~

-..~..

_~,:~-~:;>~:;~~~>-;i~~~--~-:hiiprov~~.~flo.:W.and'heat transfer mooets'forrd~te~g1ieat 'femovai rates:* An"... -,~~~:"'S-E~f:?.:~:~~~t--:~~-* improved *rep~~~eniitiioll* 9f'~~tlialpo~~sb.uia6~--~eacfor decay 1i~a{is~*aiso ~incorporat~d. _ ~- -'. :_-_ *: -~ * :;* ~~~t~ fi.~~;;;: 1

• * * * ~\\:si)ecific~tiollii:~~ifllie:m.-01-e:t~*atistlc'ie})re'senta:tion:~ofsystem'i)filameters, Dresden.:,;::.:._... _;-;.-~:--.*>~_;.. " -:*: -i_,..
• .. ~f.~*;,_

~-~~~t~t~~;~~~A~Jr~n1_'.()p~J:~~~~ii;~a.'.#l~~r:~a@i~t~pii~~~~e~~-r~0~~Jy~e~~ti.Il~,sai~tyanajys~~'._:::~:::<:.?;_--:~.:~::;<*:-,,..~ .;~Th~j>iopo~~q~c~g_es,~o:ili~:~~m{~yr~lj!9!J..tli~J:ac~!)' Js.. ~o~~le~;pi:qyid~:~~d~!!o~fil ~ *-_

• _-,-_

_.. -.:,. '_:;".. -~::-; :i.{'.*. *._ --.

• • ~-,.

~---.,_,

• • .u,(~*i!'.,il'.t...-

-.l~'"".... ~ ~-~..J.~-:..... -.,~ ***..... ~

• r

~'"°",....

• -~

J I ,.* -*).1"1* ~margin ~With~regard"tO'~soirie_.:ke¥poSt;;accident'patametera;:such *ru;. posfulated,Peak Clad*.;";*l'*--: ~:-,~_~>:~~;; ?-'-*-~,..

• ATTACHMENT. B..

'/ NO SIGNIFICANT HAZARDS EVALUATION . *sa8ed on opeiatio~ of the facility-consistent with its'histori~al lunits, consiSlent With-the

• -limits ofth~ 'existing safety analyses results, the.impro~ed re'alism.and rriore

- ~-.- :***:.representative models of.actual postitlated'plant condltibns, and the re~ultirig

• , '.. *: :* unpro~ements in key post-accident silf"ety limitS~- this change does_not s'igniflc~tly effect

....,:* *.the margi1io(Safefy.:*.

.

.)-;:r** -*.-:....... --:....

.***.. -,~,;*i. \\,~dmiceooS~Pro\\iid~'.*in :~~.~1~i~S~~:~~0Signifi~t * * *. i\\:: * *: -*" _, *: "*:.~_.~;_ *.,: ': *:Haz.ards. Considerations,;,. Final Rtile,-5J ;f.R7744, *for the application of standards-to.. *.

.; :,:*_~\\*.::*:r<i"~ :..*~ --liceiis~ 'change'request~for dete-munatioii-of.the"e~stence'o:f sigllific~t'hazards.:*:". *... :: '

_-"::: :'};;/{~~:-~:/~-:::;-;f coiisidecltions:i.Tlli~*do.cuinent'.provided ex~ples ~f amendments which are and are.not

• 0

. ' *;if~[.:Jt,j~* ~t~~~~J~~'.f,~*~~~ 1r~:~~f %*~~~~C'.~j;~t~::*'* *. :*~:. C..* *.-**** :**. __ : -..'. --~ '~ ~-~ '.?~r--::-::*-~Based**on 'ilie*.abdve; this proposed licen8e amendment -tloes not "involve any.irreversible -~ :. * -:i{;;i~JijVKt~gv~c:~~~-~;:!~,-~f~~~!~~1rui_~ti.on_~o.r,ili2~~11~~~-:~~4~i~~-~s!Abii~hsaf~tY. l~~*;:a.significant:_. .. ~ :~: :.:_;_;\\~*;-);,:: '. '~~') }~~'rel~atiori: of the '_basesforJh(lirillting' ~af~fy: ~y*steni-settirigs 'or :a.sigiiificanfrelaxa:tion of..

• • '.... ~, ~

~*.

• J

. l -~, -~::,~:~ ~~)J~~'f{;\\::::;_ip~;_b'a5e~)'.-~~~-:µi~J,ipi_\\im,g~*c~~~~9ns; ~~~9pe~ii~ij.S::_-~1}l~r~fo~e;*;based o~ the 'gUiClanc_e.

,

,,;:.?.i~*>_~;* :~,;.:'.*: ~\\>-.-;~*~proVided in ~lliePederfil ~Register :aiid:'.the ciitena ~s.tabli~hed iI(l 0 ~GFR *50;92(c),~ the :,, *

• ..,1*

~.*,,,..~-......,. **,. 1

• i*~*.,-.

~** -... *..

• r-

~

~:> ~P-::~;;~~~,"S~~-,-.:~'.~;:-: --,-p~qp~sed'p~?flg~cdtjes n<:>( 99n8~_itut~: ~-. sigitlfi~arti'_liaZ.ards.consideration:* '->. -.:...,.

~ ;.. *. "f'.: -

_, ~. -{ --~:** -AITACBMENT B NO SIGNIFICANT HAZARDS EVALUATION .ENVIRONMENTAL ASSESSMENT

• -:..... *r=~-1

,:..._.-~:~::'.. .:~..... ~:.

• 1

-:.:

• f" :-*~>...... :.. : -:..
• -:t'*:*-"*~ t*:,_* ***::

f-.. -~.. :-.-*** ....... 'i~*-~..... - *-'. :-.. / c *. . ). . ~

• • • =-*
• 1

..:\\'

• ,.-~"

.*:.~~..... :,.. . *-~.' .-.~:,_. -

-~ r***... *-i_

*"

~~**:.~...

--.-~:-.c... *~-'_!._

..... ~.*:::' -

-~

- :~.~" '::.. _** ::::_**-:-~; ~- - -.,.-.. :.~. -~: ' (.,. / ~ *

• • j'

.:-~:::"... l . '~ ...... ' ":;* = - . ~.: ~.}}