ML20086R747

Forwards Addl Info to 831230 Submittal Re NUREG-0737,Item III.D.1.1, Primary Coolant Outside Containment. Rev Identifies Portions of Sys Not to Be Tested & Responds to NRC Comments.Info Should Close SER Confirmatory Issue 28

ML20086R747
Person / Time
Site:	Byron, Braidwood, 05000000
Issue date:	02/22/1984
From:	Tramm T COMMONWEALTH EDISON CO.
To:	Harold Denton Office of Nuclear Reactor Regulation
References
RTR-NUREG-0737, RTR-NUREG-737, TASK-3.D.1.1, TASK-TM 8177N, NUDOCS 8403010120
Download: ML20086R747 (8)

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' ((?]})- one First Nttional Pitra. Chicago, Illinois

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C J. Address & ply to: Post Offica Box 767 r

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Chicago, lilinois 60090 -

. February 22, 1984 J

z JMr. Harold R. Denton, Director 4 0fficatof Nuclear Reactor Ragulation 2U.S. Nuclear Regulatory-C%nission Washington,: DC -.20555 :

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' Subj ec t : -- Byron Generating Station Units 1 and 2

'.Braidwood Generating Station Units 1 and 2 System-Leakage Monitoring NRC Docnet Nos. 50-454, 50-455, 50-456 and 50-457

Reference:

(a) December 30, 1983 letter from T. R. Tramm tu H.

R. Denton

Dear'Mr.-Denton:

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sThis is to provide additional information regarding the monitoring of. leakage from' systems outside of the containment which could be used to

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R transport-highly radioactive fluid.and gases is a post-accident' condition.

NRC' review of this information should close Confirm & tory Issue 28 (a) of ithe1 Byron SER.

Reference--(a)-provided a description of leakage monitoring l

programs to be implemented at Byron and'Braidwood Stations to satisfy the Attachment A to this Econcern identified in NUREG-0737, item.III.D.l.l..

letter.is a revised description which addresses NRC comments and a

suggestions on'the' previous submittal.- Specific portions of systems which

- willinot; be' tested are iidentified in. this revision.

These pages will be

incorporated

.into the Bryon/Braidwood FSAR at the earliest opportunity.

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AttachmentL B to this letter coni.ains a list of systems which hrue

- been; excluded from this program.

Pleas'e address' questions'regarding this matter to this office.

10ne.. signed original and fiftean copies of this letter are--

<provided:for NRC review.-

Very truly yours, M

T. R.

Tramm i-Nuclear ~ Licensing' Administrator

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' Attachment f00sfl

-18177N 8403010120 *840222* AM.

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Attachment A FSAR Revisions E.77' Primary = Coolant Sources Outside Containment (III.D.l.1)

Integrated Leak Testing Per Technical Specification 6.6.4, integrated leak tests will be performed at refueling cycle intervals 1or less on each system or portions of systems, which could potentially contain highly radioactive fluids or gases.

Station surveillances and procedures will be used to:

i a)

Monitor the leak testing of piping so that the appropriate lines are examined at the required intervals.

b). Direct leak test examinations such that systems are tested at approximate-operating pressures or higher.

c)

Align systems-such that all piping tested is properly pressurized.

d)

Identify lines which contain gases that require pressure decay,-and/or metered ~make-up testing.

e) -Quantify results of-leakage examinations.

f)

Initiate corrective action.

Leakage observed during the performance of inservice tests will

'be documented and a work request generated to repair leakage.

Work

requests of this type will be-assigned a high priority and designated as an ALARA concern to

initiate a revf..ew for possible modification to reduce leakage initheefuture.

Systems to-Be Tested The following piping systems outside containment would or could contain highly radioactive fluids and gases during or following a serious transient or accident.

Portions of systems which will not' be included in

.the integrated leak-tests are identified.

-a) -Chemical and Voluma Control (CV)

-The chemical mixing tank and associated piping are not included because'this portion'af the system is protected by check valves and normally closed. valves.

'The boric' acid addition portion of.the system is not included

'because it'is' protected by check valves and normally closed valves which prevent back~ leakage into this portion of the system.

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2-The1 resin"fillLtank-and associated piping is not included because

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• 1this: portion oflthe-system isinormally valved out-and would not be

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- c-required.to. operate..during.an accident.

i;: 3J d b): ;ContainmentiSprayc(CS) x, m

The_ spray: additive. tank and its associated piping are: excluded 4;

because this" portion of.the system only supplies 1 uncontaminated NaOH

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~toi.the' spray-eductors.

When all NaOH has been supplied to.the

eductors,. check valves prevent leakage from the CS system into this portionjof.the system.-

The 6Linch recirculation line which goes to the refueling water-i i

storage tank:has'not-been included because it is normally~-isolated

-from the. system.and is only.used to test the CS pumps in the i

recirculaticq mode.

c) :Ra'dioactive Waste Gas (GW).

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The drain. lines from the gas decay tanks have not been included

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'becausecthey.are normally isolated from the; system during plant

operation".

If any-drain line.were to be cpen, the inlet valve on that tank would also be closed, preventing any highly radioactive gases from entering this portion:of.the system.

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-The relief:-31nes from the gas decay tanks have been excluded

-because:these linesEvent directly to.the plant vent.

The relief-valves areiset.at 150Lpsi-whilefthe automatic system will divert gas-itoJthe: standby.. tank at 110 psi.

It is unlikely these lines would-An

become highly. radioactive.

4 IThe"UnitI2 tie-ins will be excluded until'such time as these s

lines comeJinto service..

. 'd ). Offgas System (OG);

-The calibration gas'_ lines to the. hydrogen analyzer are not

-included:becauseitheseglines~ carry clean bottled gas to the analyzer

forfcalibration purposes.-

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.The?p~ortionfortthe offgas? system _ associated with the steam system

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has'been excluded'because-it is highly unlikely that theisecondary.

4 teamsystemLwil10become: highly: radioactive even during a. serious

transient-or1 accident.

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-The Unit *2' tie-ins will'be excluded until such time as these slines'comeLinto service.

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Safety Injection _(SI)

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1The'~ refueling water storageLtank and its associated piping is not

- :inclu'ded because;it provides relatively clean.2000 ppm borated water

to the safety injectionipumps,. containment spray pumps, and residual

heatiremoval' pumps during an-accident.. When the level in the tank reaches:its' low ~ level, suction is transferred to the recirculation

! sump and the RWST-becomes isolated fromLthe system which prevents n

highly;contamir.ated water from entering it.

.fThe accumulator fill linet are excluded because they are used to

_ -fillt the! accumulators and would not be in use during a serious accident =and could not become contaminated with highly. radioactive water; The leako'ff lines from the recirculation line isolation valve cans'have~not beenlincluded because there is little potential for

'these lines to become highly radioactive.

LIntegrated Test LeakJAcceptance Criteria Aft'er Unit ~1 reaches full' power. operation, Edison will submit a (reportJof-all; recorded leakage and all preventive maintenance performed as

_the; direct' result of the evaluation of this leakage.

The report will also identify? general leakage criteria to De applied during the first fuel L

= cycle ~ as ;the : basis for: instituting corrective action in the form of

' preventive' maintenance.- Through'this. program's. commitment to generate

.workurequests for.all practically repairable leakage problems, levels of i

leakage will be'kept as low as-practicable. -Because. leakage problems

' presenting'ALARALconcerns will be-reviewed, the leakage criteria can be

refine;11over1 time as-more-19 formation ~ is accumulated-through testing.

-Thus,:the' criteria can.be revised;to' incorporate-new modifications and

techniques-designed to keep leakage as~10w as practicable.

In other

.words, the leakagescriteria:will be-designed such that it excludes all

practically! preventable leakage,.-based upon current. design, repair, and

. operating > techniques.

Prior to,the' start:of the second fuel' cycle, the generalEcriteriaowill.be: revised based on the experience gained during the ifirst operatingicycle on' unit 1.

These revised criteria will be used as

the basisifor the?longiterm leakage Monitoring program ~on Units 1 and 2.

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EThefinitial'; system oleakJ monitoring s data will 'be.taken af ter f uel Lload,-durin'g'thefstartupitesting.. Leakage rates observed during this n:

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period' provide a1better: baseline than those taken prior to fuel' loading.

-Leak rates observed durin~g.preoperational testingiare not necessarily

representative of operating leak rates

because of continuing adjustments

toivalve packing'and: seals, valve seatilapping, and the opening and iclosingoof:various mechanical joints.

Implementation of the program

-described above1willLassure that: initial leak monitoring will accurately iindicate' leak rates under. actual. operating conditions.

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- g-l0theritsak Testing

.. In: addition to thisfintegrated. leak test _ program, all Class 1, 2 icnd 3tsystems~will--be leak' tested at prescribed intervals,'in accordance s

feithetheErequirements 'of7Section'XI~of the-ASME Boiler and Pressure iVessel Code,E" Rules-for; Inservice-Inspection of Nuclear Power Plant-JComponents,":1980 Edition, with_addendt:through the Winter of 1981 Addenda, as described in Byron Station's " Inservice Inspection.and Testing Program Plan."'.Therefore, Class 1, 2 and 3 portions of systems excluded

.from_this leakage program, will be leak tested through.the ISI Program.

The piping and. components which make up the containment penetrations'are tested every outage as part of the 10CFR50, Appendix J

. leakage-testing program for--Type A and' Type B testing, (Type C testing is

in-accordance.with the Technical Specifications).

. -Prior to. fuel load, :all systems 'cnc portions of systems

-canstructed:in accordance with.ASME Section III'are hydrostatically tested

-to 125%;of the system's design pressure.

In the case of gaseous systems, a pneumatic type pressure decay test at :125% of system's design. pressure Jis performed.- All systems in'this~ program are tested prior to initial jj

plant;startup via the Pre-Operational Test Program.

During these tests,

system walkdowns are conducted.by the System Test Engineer and deficiencies ~arecgenerated for leaking and defective-components.

In additionLto the' individual system tests, integrated ~ type tests such as t.

cIntegrated Hot. Functional and Emergency Core: Cooling Full Flow Tests are conducted. -DuringLthese. integrated' tests,Jadditional system walkdowns are r

. conducted for vibrational testing and inspection of piping thermal

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~~ expansion.. Deficiencies are generated during these walkdowns also.

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~ Attachment B

. Systems _Exclu'ed.From d

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TIntegrated Leak Test Program 1There areiotherLplant systemsLoutside containment which are ci designed?to contain'. radioactive ~processifluids and are excluded from the aq J1eakageitestingLprogram. 'These systems _are listed below with a

" justification:for~ exclusion:

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-c Boric" Acid: Processing (AB) - The boric acid processing system is

-designed to collect borated effluent and separate it into primary

? grade.nater and 4(weight percent boric acid.

Letdown from the RCS

- would~befisolated during anLaccident and would reduce the potential for. highly _ radioactive contamination of this system.

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- Boror-Thermal Regeneration-(BR) - This system is designed to change the boron concentration of the reactor coolant system during normal operations.- _The1BR system has been_ excluded from this program because

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itais;not1 required Eco. mitigate the consequences of an accident and it Lis.readily'isolatable.

In an accident boron concentration would be controlled by_the CV systemiwhich-is included.in the leak test: program.

-FuekPoolLCool'ing(FC)-JThe

fuelpoolcooling.andcleanupsystemis

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designad to cool and-purify.the spent fuel pit water.

In addition, f

's thensystemican'be.used,to purify the water.in the fuel transfer 3 $ fcanalsp refuelin' caviti'es,Jandnthe rePueling water storage tanks.

• TJ;The system conta nsMfiltersVand'demineralizers which are designed to l provide;adequateTpurification to permit' unrest'ricted' access for' plant

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personnelsto.the'

spent fuel storage area.

Since this system has no direct" connection : to ' the: RCS, contamination caused by a serious

transient:or accidentTis4unlikely..

. Process Radiation Monitoring (PR)

The process radiation monitoring system is a " sampling" type system,1not.a process system,_and as such

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4 iutilizessvery small flow rates. - Liquid monitors are expected to creceivefa-maximum-flow rateJof;5 gpm and a. normal flowfof.approximately 3: gpm,lwhile 'gaseousimonitors are expected :to be in the 3 to 15 cfm range.1 Since;the-flows are so-'small',Jmajor leakge could not occur without diverting a significant percentage of the total' flow.. In 7 addition;1some monitors'are'used only intermittantly_and others are

-isolated,toritheiriprocess streams are.. isolated,.on-an_ESF or high radiation ~ signal.:'All. monitors can be manually isolated should the

'need.arise. ?This system lis designed'to> respond to abnormal' conditions (andoas:such,'its9 featuresfreduce:the'. likelihood of highlynradioactive

leakage from1the, systemL - For example, the containment ~ monitoring

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systemLfor theJequipment-hatch'is. totally enclosed withinlthe- ~

(equipment 1 hatch? and;.iss normally. valved out.

Some penetrati'ons.into

? containment are normally op'en but would isolate on an ESF' signal.

Therefore,< uncontrolled leakage'of highly radioactive effluent ~from lthe"PR system-is unlikely.

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' Process' Sampling (PS) -~The process sampling system interfaces with

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. ~variousxindividual systems and thus could also be discussed on a case by case-basis.s v However, there iare-generic aspects of the system which

lllustrate'thefjustification for not including PS in this program.

NearlvJall'of;the PS system-is normally_ isolated.

None of the

monitors-can beJautomatically activated.

At this time only one monitor is designed.for continuous operation (containment sampling)

?and itLis? automatically isolated on a high radiation signal.

Maximum' flow in-this system is expected to be 1900 ml/ min. or

.approximately;1/2 gpm. - It is clear that the potential for major 11eakage1is low.

For example,1a 25% loss of the fluid flow from the system would represent a maximum of 1/8:gpm.

Since1the System is-Efrequently1 operated by the Rcdiation Chemistry Department during

. normal;plantfoperation, it;would be unlikely that afloss of' flow would gofundetected.

While in use, Rad-Chem monitors the radiation levels

'arcund the'equipmentifor personnel safety and would therefore detect Lincreasesrin radiation levels" caused:by leakage.

-AsEstated above,--tnis-system is normally isolated and sampling-is.

intermittent.

All of~the piping is ofjsmall diameter:' most is in the 3/8;to'3/4Linch. range.DPiping lengths;are; minimized for sampling considerations.x: Plating-out, radioactive decay, and other effects

-could result-in inaccurate samples if-piping lengths were not kept to

'a minimum. - In addition, the' sample panels, where the greatest probability forgleaksge extists,'are.kept at a negative pressure by theyfiltered1 ventilation. system.:

ReactorJBuilding Equipment Drains (RE)

The reactor building

~ equipment drain system, except for & line which extends'from the

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1 reactor coolant _ drain ~ tank to the waste gas compressor, was excluded

,because thefdischarge valve on the pumps is'nornally closed during plant 4 operation and. receives and ESF signal.

Therefore, it would not become highly' radioactive even during an accident.

Reactor Building Floor Drains (RF) - The reactor building floor drain system.was--not included because this system'would become isolated from Lthe auxiliary bulding during an accident through an ESF signal.

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' isolating, contaminated" water would remain in containment and be

. recirculated by the RH, CS, CV,-and/or.SI systems, all of which will l be < monitored -in this prograrn.

Primary Containment' Purge-(VQ)

The primaryL containment purge system

.was excluded because its isolation valves are normally closed al'd itheir.usesis governed-by the" Technical-Specifications.

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Auxiliary Building-Equipment Drains (WE) and Auxillapy Buil. ding Floor These sy9tms were not included because they would not

-Drains (WF)

L contain.highlyLradioactive fluids.- By-controlling the leakage.from

.those systems whichJmay contain. highly radioactive fluids during a

~ serious transient ~or accident, it is unlikely that the drain systems L

- lwill' experience uncontrolled increases in radioactivity.

In addition, 4most drain system.! piping is not pressurized and the majority of-the s

. piping connections are welded, as such, the likelihood for' uncontrolled leakage:is-low.

Solid Radwaste Disposal-(WX) and Chemical Radwaste Disposal (WZ) - The radwaste systems a' e designed to process radioactive waste produced by r

the plant'. LThese systems do not connect directly to the primary systems'-and therefore it is'unlikely they would-experience an uncontrolled increase.in radioactivity.

Their use during an accident would require operator actions which would allow for the implementation of-special precautions Lppropriate to the particular situation.

In additon,-theffrequent visual inspection of radwaste systems would have

a -highly negative impact on the station's ALARA program.

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