ML20198R216

Forwards RAI Associated W/Review of AP600 TSs SER Shutdown Conditions

ML20198R216
Person / Time
Site:	05200003
Issue date:	01/16/1998
From:	Quay T NRC (Affiliation Not Assigned)
To:	Liparulo N WESTINGHOUSE ELECTRIC COMPANY, DIV OF CBS CORP.
References
NUDOCS 9801230249
Download: ML20198R216 (9)

Text

_ _ _ _ __ ___

c ,

f January 16, 1996 -

t  ;

g y ;r # 3-t  ; ,

y

l

. 7 Nir, Nicholas J. Liparulo, Manager Nuclear Safety and Regulatory Analysis

'[ ,

!t > Nuclear and Advanced Technology Division

/

- , (- \$estinghouse Electric Corporation ,

~ P.O. Box 355

. Pittsburgh, PA 15230 .

SUBJECT:

REQUEST FOR ADDITIONAL INFORMATION (RAI) ASSOCIATED V6Y) THE *

, REVIEW OF THE AP600 SHUTDOWN RELATED TECHNICAL SPEClht.4TIONS (TSs) t

Dear Mr. Liparulo:

The Containment Systems and Severe Accident Branch has requested additional inic,mation to complete its input for AP600 TSs SER related to shutdown conditions. The RAls are attached as an enclosure to this letter.

if you have any questions regarding this matter, you may contact me at (301) 415-1118.

Sincerely, original signed by:

Theodore R. Quay, Director Standardization Project Directorate Division of Reactor Program Management Office of Nuclear Reactor Regulation Docket No.52-003

Enclosure:

As stated ggggggr cc w/ encl: See next page 4 .

. DlSTRIBUTION:

f, Docket File - PDST R/F TQuay

• b s- - PUBLIC -TKenyon WHuffman JSebrosky DScaletti JNWilson ACRS (11)

JMonninger .

WDean,0-5 E23 JKudrick,0-8 H7-JMoore,0-15 B18 CBerlinger,0-8 H7

% b. )- '

4

?

^

+ 'SNewberry,0-8 E2 GHolahan,0-8 E2 JLyons, 0-8 D1

'[- i AChu,0-13 H15 ,

's

• py [e , e

• y, MReinhart,0-13 3 H15- .

I DOCUMENTNAME: A:TS-6-Ol.SER - a+"

l l ' TO Mve a copy of this document, indicata in the box: "C"

• Copy witnout attachment /en' closure. "E",= Copy a with attachment / enclosure "N" = No copy vin 6th ,

,,1 D; POST:DRPM ] l 1, OFFICE - PM:PDST:DRPM I BC:SQSB:QSSA D;DSSA f u) ,

ef QATE WCHuffmitrC NAME' CBerlihgerin GHolahph h4 TRQuay4D4 l s .,

01/)1/98 - JW 01/lv/98

01/13/98 01/14/98 -- l ' -

/'u -/-

9901230249 990116

' '( OFFIC 7

RECORD COPY-i s

PDR ADOCK 05200003 \ 'l h. h, ilcll.

E PDR  ! .

t P . . _ _ . _ .-, .-

Mr. Nicholas J. Liparulo Docket No.52-003 Westinghouse Electric Corporation AP600 cc: Mr. B. A. McIntyre Mr. Russ Bell Advanced Plant Safety & Ucensing Senior Project Manager, Programs Westinghouse Electric Corporation Neclear Energy Institute Energy Systems Business Unit 17761 Street, NW P.O. Dox 355 Suite 300 Pittsburgh, PA 15230 Washington, DC 20006 3706 Ms. Cindy L. Hasa Ms. Lynn Connor Advanced Plant Safety & Licensing Doc Search Associates Westinghouse Electric Corporation Post Ofnce Box 34 Energy Systems Business Unit Cabin John, MD 20818 Box 355 Pittsburgh, PA 15230 Dr. Craig D. Sawyer, Manager Advanced Reactor Programs Mr. Sterling Franks GE Nuclear Energy U.S. Department of Energy 175 Curtner Avenue, MC 754 NE 50 San Jose, CA 95125 19901 Germantown Road Germantown, MD 20874 Mr. Robert H. Buchholz GE Nuclear Energy

. Mr. Frenk A. Ross 175 Curtner Avenue, MC-781 U.S. Department of Energy, NE-42 San Jose, CA 95125 Office of LWR Safety and Technology 19901 Germantown Road Barton Z. Cowan, Esq.

Germantown, MD 20874 Eckert Seamans Cherin & Mellott 600 Grant Street 42nd Floor Mr. Charles Thompson, Nuclear Engineer Pittsburgh, PA 15219 AP600 Certification NE 50 Mr. Ed Rodwell, Manager 19901 Germaritown Road PWR Design Certification Germantown, MD 20874 Electric Power Research Institute 3412 Hillview Avenue Mr. Robert Malers, P.E. Palo Alto, CA 94303 Pennsylvania Department of Environmental Protection Bu eau of Radiation Protection Rachel Carson State Office Building P.O. Box 8469 Harrisburg, PA 17105-8469 l

SCU RAls Related to / P600 Shutdown Technical Specifications 480.1117F Table 3.3.21, Function 19, " Containment Air Filtration System isolation" receives an isolation signal based on Containment Radioactivity High 1. This function should be operable in modes 1-4 (similar to containment isolation and containm.at cooling) and during core alterations and movement of irradiated fuel, consistent with Westinghouse standard sechnical specifica-tions, in addition, Westinghouse should explain why the reference trip setpoint is set at 2 R/ hour as compared to the standard technical specifications reference value of 2 times background?

480.1118F What is the basis for the Cr,atainment Pressure - High 2 trip setpolot of <8.0 psig, Table 3.3.21, functions 1,4, and 12. For the safeguards actuat!on, function 1, the setpoint appears to be significantly higher than that specified in SRP criteria (2 psig) or the value in standard tech specs (3.6 psig)? In addition, SSAR Chapter 7.2 Logic Diagrams and Table 7.31, indicated that this actuation occurs on a High 1 setpoint in lieu of High 2. Westinghouse should resolve this discrepancy and explain what function the High 1 r!gnal performs.

480.1119F TS Table 3.3.21, function 13 (e) on CMT actuation should be structured like function 13 (d). Why are the applicable modes listed? The applicable modes for PRHR actuation on a CMT actuation should be the same as function 2. Note that the applicable modes for PRHR actuation on ADS actuation are not listed for function 13 (d).

480.1120F The main control roem isolation and air supply initiation of Table 3.3.21, function 20.a. based on control room air supply radiation - high 2, should be operable during core alterations, not just for movement of irradiated fuel assemblies (See Note h of funct'. n 20).

480.1121F TS 3.3.2 specifies that the ESFAS instrumentativn for the patsive containment cooling system (function 12) shall be operable with the reactor shut down less than 100 hours0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br />. TS 3.6.7 specifies that the passive containment cooling system shall be operable wt.en ine calculated reactor decay heat is greater than 6.0 MWt. These two specifications should be consistent. A specificatior. 'or time is likely to be easier to verify than one based on decay heat levels if the decay heat criteria .. utilized, then the basis should discuss what standard is used and the corresponding input assumptions, if decay heat levelis retained in the applicability of TS 3.6.7, it shoold be corrected to state 6 MWt not 6 MWA.

480.1122F TS 3.3.2 on manualinitiation of contairment isolation, function 3, is not applicable in mode 6 for valve isolation functions whose associated flow path is isciated. Why isn't this exception also cited for mode 5?

480.1123F TS 3.3.2 on the manual initiation of IRWST injection line valve actuation, function 22.a. should be operable in modes 5 and 6, as discussed in the TS basis.

Enclosure 1

.. . 2-480.1124F . .

TS 3.3.2 on the safeguards actuation of the IRWST recirculation valve actuation, function 23, should discuss the required coincidence with IRWST level low 3 as discussed in the toch spec basis.

480.1125F A number of AP600 technical spoolfication refer to a condition invoMng *... MODE 6 with upper intsmals in place and cavity level less than full.' The staff believes these should be corrected to refer to MODE 6 with upper intomats in place er cavity level less than full (Examples: TS 3.3.2 Conditions W, X, and Y, Footnote g of Table 3.3.21,3.4.14,3.6.8,3.6.7) . In addition, the basis for these TSs should also be corrected. For example, TS 3.3.2 actions X.2 and Y.2 spec 6fles actions to be in Mode 6 with the upper internals removed and the savity full, whereas, the basis for this toch spec, spoolnes being in Mode 6 with the upper internals in pleos and the refueling envity level less than full. TS 3.6.7 uses and/or rather than just or.

Westinghouse should also clarify that cavity refers to refueling cavity and specify what consti-tutes a full cavity level (e.g.,23 foot above the reactor vessel flange). This comment is also applicable to the investment protection procedures 1.2,2.2 2,2.3,2.4,2.8 and 3.2 in SSAR Chapter _16.3.

480.1126F-

. Westinghouse should explain why the remote shutdown workstation technical specification (TS 3.3.4) is only required in modes 137 The basis for TS 3.3.4 discusses use of the remote shutdown workstation to place and maintain the plant in MODE 4 How can the plant be maintained in MODE 4 from the remote shutdown workstation, when the RMS is not required to be operable in MODE 47 480.1127F ~

A number of technical specifications have required actions to establish a visible level in the presserizer (Examples: TS 3.3.2 Conditions U, V, W, X, Y. 3.4.13, 3.4.14, 3.5.3, 3.5.7). The basis for these technical specification should be expanded to explain what is meant by " visible" levelin the pressurizer.

480.1128F How would technical specification with conflicting required actions be dealt with? For example, assume that during Mode 5 the automatic depressurization system requirements of TS 3.4.13 or

. 3.4.14 were not met and the operators were instructed to open the RCS in conjunction with the action statements in addition, assume that containment closure could not be achieved in accordance w4h TS 3.6.8 and the operators were instructed to close the RCS in conjunction with the action statements. Are there other cases like this in the AP600 technical specifications?

~ 480.1129F Required Actions statements E.1 associated with TS 3.5.7 has the operators initiate action to be in Mode 5 with the RCS intact. However, the basis for TS 3.5.7, required action E.1, states that

\be operator should place the plant in Mode 5 with the RCS open. Westinghouse should correct :

this conflict, c

1 .. . .,

I '. '

. 3--

480.1130F The shutdown operability requiremords for the core makeup tanks does not cover reduced inventory conditions. ";- " ";, the operability requirements for the core makeup tanks when in mode 5 with the RCS pressure boundary intact and nt, visible level in the pressurizer need to be addressed (See T8 3.5.3).

460,1131F Why is the format of the surveillance requirements for TS 3.5.8 different from that for TS 3.5.77 480.1132F There are several inconsistencies between the *1RW8T Shutdown, RC8 Reduced inventory" T.8. 3.5.8 and its BA818. TS 3.5.8 is applicable at all times during mode 6 per the applicability statement. However, the basis discussion on apphcability states that this LCO is only applicable in mode 6 when the upper intomals are in place and the cavity level is less than full. In addition, tne LCO description states that it is not applicable during filling or draining of the refueling cavity.

Condition C of TS 3.5.8 seems to cover all states of filling or draining of the refueling cavity such that as leng as the combined volume of the IRWST and refueling cavity is within 3 percent of the IRWST nominal volume, conditions comply with the TS. If the T8 does not apply to filling or draining of the refueling cavity or other conditions within MODE 6, Westinghouse should address how those conditions are covered.

480.1133F The discussion of the Containment TS 3.6.1 applicability in the BASES states thct *Except in Mode 5 with the loops not full, the time to boiling and core uncovery is significantly reduced due to reduced Reactor Coolant System inventory". This statement does not make sense and should be corrected or explained.

480.1134F The Applicability discussion in the BASES for TS 3.6.3 states that , in addition to the pressure and temperature limitations of these modes, there is a large inventory of coolant during Modes 5 and 6 and, therefore, the containment isolation valve specifications are not required during these Modes; The inventory of coolant is no greater during Modes 5 and 6 than during operational  ;

Modes 14 and is, in some instances, less during reduced inventory and mid-loop operations. 1 This statement does not appear to be accurate and the BASES should be corrected to support the applicability discussions.

480.1135F Containment isolation Valve TS surveillance requirement SR 3.6.3.4 verifies the isolation time of each automatic containment isolation valve. The TS BASES for SR 3.6.3.4 states that the isolation times are provided in SSAR 6.2.3. SSAR 6.2.3 references SSAR Table 6.2.3-1 which has specific isolation times for a few of the containment isolation valves. However, the majority

' of the valves are listed as having a closure time which is " Industry standard for the valve type."

The statement on industry standards does not provide any upper limit for the closure times.

SSAR section 6.2.3 should clearty state that all contairi,nont isolation valves which have automatic closure have a closure time which conforms with ANS 56.21976 and are less than 60 seconds as specified in the NRC standard review plan. This is consistent with the wording in :

SMR Section 6.2.3.4.1.

' 480.1136F SSAR Section g.4.7.2.1 states that the containment air filtration system supply and exhaust air.

lines penetrations are 36 inches in diameter with 16 inch branch lines containing containment isolation valves. SSAR Section 6.2.1.5.3 states that two 10-inch diameter flow paths were

, modeled in the minimum containment pressure analyses to simulate containment purge lines, 1

__ ______m_____2-____._ mm_._____

(..

4 Westinghouse should explain why the analyses did not model the actual plant design and why g l this analysis is consercive.

9

_ 480.1137F Tim Applicab!e Safety Analyses discussion in the BASES for TE 3.6.4 states that'the extemal pressure load from inadvertent containment spray system actuation was evaluated. It is the -

Matts understanding that inadvertent containment spray was not a credible event for AP600.

Please provide an explanation of this stateinant.

,480.1138F The Applicable Safety Analyses discussion in the BASES for TS 3.6.5 states that such things as

- worst single failures of Residual Heat Removal and the Containment Spray System were ,

considered in the postulated DBAs. This discussion is clearty net applicable to AP600 and should be corrected.

480.1139F The required actions for technical specifications that have mode 5 as the end state should be

- consistent. For example, required action C.2 of TS 3.6.6, "PCS - Operating," should be 'evised to state "Be in MODE 5 with the RCS intact and visible level in pressurizer". If the PCS in not -

operable in MODES 1-4, TS 3.6 6 eventually directs the operator to be in MODE 5. However, when the plant reaches MODE 5, the PCS would sth! bs inoperable ud the operator would enter

.TS 3.6.7 action statement which requires operators immediately initiate action to be in MODE 5

- with the RCS intact and visible level in the pressurizer.

• iew should be performed to ensure that the end state of required actions in MODP , i p' ace the plant in an action Statement for MODES 5-6 that require imme etc -

T so, the end states for the TS in

=

MODES 14 should be consi .s with tha+ t 480.1140F The Applicable Safety Analyses discussion in the BASES for TS 3.6.6 states: "The analyses and eva'uations assume a unit specific power level of 1933 MWt, one passive enntainment conditions of 120 F and 1.0 psig? This statement does not make sense as written and should be corrected.

480.1141F -

The applicability of TS 3.6.7 can be interpreted 2 ways (either Mode 5 at all times and Mode 6 with deca / heat > 6.0 MW or Mode 5 with decay heat > 6.0 MW and Mode C with decay heat >

6.0MW). This should be clarified. In addition, TS 3.3.2. function 12(s), should be consistent V with TS 3.6.7 TS 3.3.2 requires the ESFAS instrumentation for the PCS to be operable at all time in Mode 5 and only within~100 hours of shutdown in Mode 6.

1480.1142F

- Tha words "with the reactor shutdown"in the applicability statement of TS 3.6.7 and its BASES

are urasessary and should be deleted.

- 460.1143F -

TS 3.f J and its corresponding BASES should be consistent. The TS references water storage tanis volume. whomas. the BASES discusses IRWST level. The correct terminology should match the display of the instrumentation used in the control room.

- 480.1144F -

The be. it %r TS 3.6.7 discusses DBAs'during shutdown. What are they and how were the

DBAs 2.$.olished?J Q

_ .m - - _ _ -_.2._ 22. _ -__ _ - - _

. 480.1145F The Passive System Shutdown Mode Matrix Table on technical specification BASES page B 3.0-5 is mislead;ng when compared to the actual toch specs and should be corrected. For example, the table implies containment cooling consisting of 2 water flow paths is required at all times in MODE 6 when the reactor intemals are in place. However, TS 3.6.7 and 3.3.2 indicate that the containment cooling water paths are only available when decay heat is greater than 6 -

MW.

480.1146F BASES Figure B 3.6.61 of TS 3.6.8 should be incorporated into the TS and not just the bases, since it establishes the required completion time to achieve containme it closur J.

480.1147F The LCO conaitions for TS 3.6.8 state that a number of actions must be completed before

, "rteaming into the containment *. The initial conditions uneter which this time period is determined needs to be clarified. Specifically, what initial RCS volumes and temperatures are assumed in the calculations. What dec3y heat correlations are applied? How is steaming into containment detined for cases were the RCS is initially bottled up and then depressurized through ADti, ie.,

is it the time to heat-up to 212 F or the time to actual steam release *hrough ADS stage 47).

480.1148F in generating BASES Figure B 3.6.8-1 of TS 3.6.8, how were loss of inventory events factored into calculation the time available prior in RCS boiling? The time available to achieve contain-ment closure can be dramatically reduced for a lots of inventory event during shutdown operations compared tu a loss of residual heat removal event. Loss of inventory events are recognized as a potentialin the AP600 PRA t" ihr 54). Because the actual shutdown event that requires containment closure cennot be pivected, the time available to achievs containment closure should be based on events with the shortest time to steaming to the containment. The figure provides the time to achieve contair went closure for specific plant configurations. Unless the configurations are bounding, a discust on should be provided for determining the time to ,

containment cloure for other configurations, e.g., the RCS, IRWST, or cavity water is at a higher ~

( temperature than assumed for the Figure curves.

480.1149F g TE 3.6.8, LCO (d) st.culd be expanded to include all non-essential penetrations. For example, it should state "All non-essential penetrations or penetrations providing direct access from the containment atmosphere to the outside atmosphere". The contahnent isolation instrumentation is required for all penetrations in modes 5 and 6, as discussed in TS 3.3.2, except if the flow path is isolated. TS 3.3.2 is not limited to the penetretions discussed in TS 3.6.8.

480.1150F TS 3.6.8, LCOs (a) and (b), should have similar wordig v.e.,3.6.8b snould read: One door in each air lock close:1 or, if open, the containment air loJ..s shall be clear of obstructions such that an air lock door can be closed prior to steaming into the containment).

480.1151F TS 3.6.8 EAGES should be expanded to discuss the need to close containment to limit the release of fission products following an event during shutdown operefons. The BASES Background statement "... accident analyses have shown that containment c40sure capability is

< D91 required to meet offsite dose requirements"is inconsistent with the level 2 shutdown PRA which takes substantial credit for containment closure to ensure a mitigated release.

~

p .~ ,' ._

480.1152F in generating BASES Figure B 3.6.81 of TS 3.6.8, why is there a difference in the slope of ths ,

top two curves verses the k,wer two curves? The time offsat is appears to be due to the .

dmorences in inventoy but all four curves should have a similar shape based on decreasing

- decay heat. Provide the assumptions used in development of the four curves. For the curve 1

during Mode 5 with the RCS Intact, what body of water (RCS or IRWST) is assumed to host up to 212 F and steam the containment?

480.1153F

' in TS 3.6.8 BASES dismssions, provide a desenption of the self-contained power source used to close the equipment hatch.

460.1154F -

The Background discussion in the BA8ES of TS 3.6.8 make a cistinction betwcen containment

" closure prior to steaming into the containment" and " closure prior to reaching boiling conditions

' within the tuactor coolant inventory." What are the differences between these two states and how do these differences relate to containment closure toch spec actions?

- 480.1355F :

The TS 3.6.8 BASES should discuss that any temporary penetration covers used for containment closure should be capable of meeting 45 psig design pressure as stated in the rhetdom  ;

evaluation report, WCAP-14837.

430.1156F The LCO 3.6.8 BASES should be revised to indicate how the number of bolts needed for

- equipment hatch closure during shutdown conditions will be determined. Westinghouse should uiscuss what engineering analysas or testing needs to be performed to confirm that a sufficient number of bolts for equipment hatch closure has been specified. Westinghouse should also provide the specific design basis criteria at is using for defining containment closure during shutdown Moues 5 and 6.

480.1157F TS surveillance requir6mnt 3.6.8.3 should be expandea to include all the requirements discussed in its corresponding BASES discussion 480.1158F TS 3.7.6 should be revised to be applicable during any core alterations consistent with the way core alterations are defined in TS 3.9.4 and in standard tochnical specification. - In addition, other

- areas of the technical specific <on should be reviewed to refer to core alterations instead of fuel movement (e.g., TS 3.3.2).

480.1159F~

A technical specificati<. .) equivalent to standard technical specification STS 3.9.4 specifying the status of containmens penetration requirements during core alterations and movnmem of irradiated fuel ass 6mblies within containment should be provided (similar to current AP600 -

1TS 3.6.8 with applicability during core alteratioas). '

480.1160F A safe enditate condition for a number of technical specification is Mcde 5 with the RCS Intact and visible level in the pressurizer. Discussions in various APS00 technical specification BASES

.g'  : impl43 that RCS intact means that the RCS & assure boundary is closed. Discuss the use of

.nozate dams.and the implications of requiring tae removal of nozzle dams to re-establisti a i closed RCS pressure boundary and the time requirements to remove the nozzle dams. Discuss N

a.we.g.t. ____m - - - - - - -----:- -- =--

, the RCS pressure resulting from a loss of RHR event reqalring the RCS to be closed up. >

WCAP-14837 indicates that the nozzle dam design pressure is 40 psia and that the maximum pressure following a loss of shutdown cooling in Mode 5 with the RCS pressure boundary open is lest than 32 psia. What adions would be taken to achieve an intact RCS in accordance with toch spec 3.6.7, if the passive containment cooling system becomes inoperable with the nozzle dams instc,Iled?

[

440.1161F The discussion of the LCO selection criteria on TS introduction page 16.1 1 states that AP600

{ structures, systems, and components selected in accordant.e with the fourth criterion and included in the TSs are those which have been found to be necessary to meet the NRC core -

melt frequency (emphasis added). This should be cerrected to state it.at items selected under criterion 4 include those CSCs important for meeting the Commission's Safety Goals and Severe Accident Policies, which is consistent with the policy statement. This would include the large early release frequency and conultional containment failure probability.

\

E c.

8-480.1162F The terms and conditions referred to in AP6CC technical specification during Modes 5 and 6 appear to be excessive and essentially establish multiple sub modes. If possible the Modes should be simpi;fied and made consistent between the various specifications.

Mode 5 (all head bolts tensionedi Mode 6 (1 or more head bolts not tensioned)

Mode 5 (all times) Mode 6 (all times)

- SL 2.1.2, TS 3.1.1, 3.1.9, 3.3.2, 3.4.3, 3.4.9 - TS 3.4.3,3.5.8 RTBs open Reactor vessel head is on

- TS 3.3.1 Note (g) - TS 3.4.15 Whenever the RTBs are closed Upper intemals in place and cavity level less

- TS 3.4.5 than full l - TS 3.3.2, e.g. Required action X.2 RTBs closed and PCS capable of rod with- Upper intemsts in place and refueling cavity drawal levelless than full

- TS 3.3.1Nc'.e (j) - 3.4.14, TS 3.3.2 Note (g)

RCS pressure boundary intact Upper intemals removed and the cavity full

- TS 3.3.2 Note (i), 3.4.13, 3.5.5, 3.5.7 - TS 3.3.2, e.g. Reguired action X.2 RCS pressure boundary intact and a visible Reactor shut down less than 100 hours0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br /> levelin the pressurizer - TS 3.3.2 Ivote (e)

- TS 3.5.3 RCS intact and visible level in pressurizer

- TS 3.3.2, e.g Required Action Y.1 RCS pressu' ' bnundary open

- TS 3.4.14 RCS open and visible levelin pressurizer

- TS 3.3.2,e.g Required Action X.1, 3.4.13,3.5.7 RCS open and level not visible in pressurizer

- TS 3.3.2, e.g Required Action ~.;.".

3.5.8 Above the P-12 interlock

- TS 3.3.2 Note (c)

During movement of irradiated fuel assem- During movement of irradiated fuel assem-blies blies

- TS 3.3.2 Note (h) - TS 3.3.2 Note (h)

RNS aligned and open to the RCS and RCS temperature < 350 F

- TS '3.4.15

f,

.g. .

480.1163F _

+

Table 16.31 should be corrected to indecate two AC power source 1 [2(1)) for reduced inventory conditions.

480.1164F '

SSAR Logic Diagram 7.2-1, Sheet 20, indicates that DAS has a containment isolation and PCS initiations feature which actuates on containment temperature, it is the staffs understanding that the setpoint for this DAS actuation is 200 F(although this value cannot be verified in the SSAR) Provide information on the basis and analysis supporting this 200 F containment temperature actuation by DAS. The shutdown PRA assumes containment isolation is accom- ,

plished prior to temperature reaching 145 F. Discuss what is meant by

• selected containment isolation actuation" and how that relates to the isolation of containment penetrations required by tect;nical specifications, including all non essential penetrations.

480.116bF ,

The technical specification course of action for the following condition needs to be explained, if the IRWST exceeds the water ten;perature limits established by TS 3.5.7, the ac ion statem;vis associated with TS 3.5.7 would require the operators to close the RCS. However, the basis for TS 3.5.7 (i.e., if IRWST temperature is not _within limits, the PRHR heat transfer assumed in safety analysis may not be available) may lead the operators to question the operability of the  ;

passive residual heat removal heat exchanger discussed in TS 3.5.6. TS 3.5.5 would eventually instruct operators to open the RCS if the PRHR HX was not operable.

4 2

/

l 8

4 q

N

,-.. . , ,_ , .. , . . _ . . - ._ - .-