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{{#Wiki_filter:- f g. l DISTRIBUTION: t Docket File MM 4 UI Reading MRushbrook ( Docket No. STN 50-561 (MEMORANDUM FOR: Olan D. Parr, Chief, Light Water Reactors Branch No. 3. Division of Project Management FRG1: Thomas H. Cox, Project Manager, Light Water Reactors L l b' . - - Branch No. 3, Division of Project Management I x d ,7,1. BSAR-205 SER DRAFT INPUT FRCH I&C BRANCH, .z 7 8 = 7
SUBJECT:
c ' / CONCERNING RPS-II "'r' . 2. MANAGEMENT OF REVIEW OF B&W TOPICAL REPORT S {,.3 ' g.. ~.2.N0..BAW 10085P" REACTOR PROTECTION SYSTEM" . ;,n, :, .u . ; ay ;- f .x w.t [,',. report submitted September 1973) and the RPS-II reactor trip s i
- isubject of the report) has been referenced in Bellefonte, Greenwood.
i d DWHP-1, 4, Pebble Springs,' BSAR-205 and.Greene County applications. .y TER's issued on these projects, without exception, state that it is the .etaff's intent to complete the review of the RPS-II topical report prior l h, to the submittal of the FSAR on.that docket.' Examples are included as '/ Enclosures 1,.2and3. ,C l . &., p l We expect the Bellefonte FSAR to be submitted in December this year. The i 4s BSAR-205 (standard 205 plant NSSS) PDA decision will probably take place t before that time, and is currently scheduled for September. It seems entirely appropriate and warranted that a PDA for the standardized 205 { M system should require a more specific approval of the RPS-II than the i prior custom review SER statements which stated only that the design was <"under review" and that we intended for the review "to be completed prior . jto.FSAR sutenittal". Specifically, I believe that we should be able to state
- i i.in the-BSAR-205 Report to the ACRS that the RPS-II design is acceptable
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' ", topical report is planned to be completed by September 1977. 5 JNow, a brief look at the current technical review status regarding RPS-II. From discussions with Walter Pike (LPM, Bellefonte) and Jim Thomas (LPM, B&W topicals) who have both recently discussed the progress of the RPS-II topical with Ron Naventi (IEC Branch reviewer), it appears that a completed safety evaluation on the RPS-II topical is planned for about September 1977. Further, the safety evaluation will probably impose some plant specific a 8201120227 810403 PDR FOIA MADDEN 80-515 PDR
? W,Y 4 Ull Olan D. Parr.. 4 -AN requirements on the use of the RPS-II design that will necessitate review e.4. of additional applicant submittals.regarding RPS-II during individual g OL reviews. T E, So it would appear that the RPS-II topical report review will be completed q?,just prior to the Bellefonte FSAR submittal.that the FSAR is already complete and in t TVA told the Bellefonte LPf.i on 04/20/77 The' BSAR-205 report to ACRS and, ultimately, SER, must be issued well ptior M g to the probably completion of the RPS-II review as currently planned. [ik"Cr.. Since we are within 5.1/2 months of the topical review completion, almost .v ?. 3 years since starting the review, I believe we should now be able to T .r : make an explicit preliminary design. approval statement regarding RPS-II in. @pc' the BSAR-205 report to.the ACRS., '.., '.,- 'c g ;. '.4',3' By copy of this memo, I am requesting (you to' authorize a modification to ' ; g the SER input submitted for BSAR-205 February 28, 1977, R. Tedesco to - ' g D. B. Vassallo) as it concerns the RPS-II. shows the current ' g.6,., RPS-II position, and Enclosure 51.s 'the-suggested modified statement. The ~.. Epl modified position statement shows that there has been progress in the 6(review of RPS-II'(which should be-necessary to a PDA issuance on BSAR-205) that we expect to' require further review work, and that we have reasonable ,,,..tv assurance that any'further. requirements,that we develop will be resolved
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. ' f., J ~a..(6 Further, 'I believe that'we should exert additional effort at this time, ~ .. a J' in both DSS and DPM, to ensure that the RPS-II review is concluded by i'.!(;i, September 19771. Extra effort now should ensure that we enter the OL ,.6; review stage of a number of custom reviews with at least a preliminary ..? j-j. design approval of the RPS-II. A useful step in this direction would be j ;,g>R Topical Report Program Manager) concerning the priority of effort wewa brie w,4Z should place on the,RPS-II review. f.. g, t
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Enclosures:
J. 7 ' 7,, As Stated . i. F,M ~ ., cc:: D. B. Vassallo >P,. : I.R. C. DeYoung ~ ~ T. Ippolito S. Varna LWRf3: LPM TCox:ca N ...,5/of/77_. _
SCloSdfC ,,], .Ccca.:.c: 2 -4]} Q ~ 431 7-3 );"*gm [E*Q cp 77/C $El_LgFoM NW(J:WK PLst7 ?' ~ ,} hr est 3 We have reviewed these changes and have concluded that g., [p".,, these design changes provide an equivalent or better degree of i safety than that of the Rancho Seco plant and are in conformance p .su to IEEE Std 279-1971, and therefore find them acceptable for the [... 4 h(, construction permit review stage. However, in view of the unique v {p{6 design features and hardware utilized (i.e., use of integrated solid hd state logic and mini-computer technology in the calculating module), pp ish the total system acceptability is conditional pending our generic re-3'., h'V' = m view of the new B&W RPS-II design. This design is described in B&W l,j L[w Topical Report BAN 10057 (Reactor Protection System, September,1973) U' and will be reviewed by the Staff prior to the operating license stage. The applicant has replaced the high reactor building pressure l30 trip with a low pressuri:er level trip in the new RPS-II design. h.. (The new design retains the diverse low reactor coolant pressure !f* r tl trip. ) The Staff's position is that since the analysis of the h,' effectiveness of the ECCS performance assumes a reactor trip at g 3,, ECCS actuation, we requite that diverse signals be ised to trip 1 g,. rp the reactor. At this point in our review there is insufficient !* ' ~ information to evaluate the acceptability of the low pressurizer f.k, level trip as a diverse reactor trip for this purpose. Therefore, }:v. we may require that the Bellefonte RPS design be revised to provide .l':1.';. a reactor trip on high building pressure for this diversity as is the citee on plants previously reviewed and approved. f,. P {,
..-.me ~ EUc4.osdLe G ) ' ' -i. gg y /2rft., 7ME' M8T IM$5 MM MC kp-f.f T 7.0 !NSTRL*ENTATION AND CONTR0t.S l.hd 7.1 !ntroduction [1, '(4. The applicant has identiffed the safety-related instrumentation and control systems NI and the apolicable safety criteria. PGE has documented its intent to design and implement these systems in accordance with the criteria. It is concluded that imple-mentation of these systems in accordance with the criteria provides assursnce that t the plant will perform as designed in formal operation, anticipated operational transients, and postulated accident conditions, and meets the applicable requirements -( 44 of General Design Criterion 1. .". !J 7.2 Peactor Protection System (RPS) ~ . J,I
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- The RPS design, designated RPS-II, is a relatively new concept using a mini-computer
,' f or " cal aiating module" in each RPS channel to perform various calculations that -p provida the following trips: axial power offset, reactor coolant pump status, low ..4 i w DN3)., and tower /a7 startus. This design is identical to that proposed for Bellefonte, Units 1 and 2 and WPPSS. Units I and 4 I" s-RPS-!!, described in B&W Topical Report BAW-10085, is under generic review. RPS-II uses oigital computer modules in each of the four RPS channels. e i We hcve determined that an applicant comitment to a generic resolution of RPS-II is ', 1, acceptable. In the event the RPS-II design has not been approved by the time of FSAR e 4 is sub.ittal, an RPS design must be provided such that it will achieve a degree of ' safety .( adequate for the design of this plant. 6
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n 7.2.1 Protection System pesponse Time Testino .j The aoplicant has agreed to test response times from sensor input to final actuation device output. This comitment is consistent with Standard Technical Specifications i recuirementi and provides sufficient assurance that the applicant will include the recessary t.esign into the system 50 as to make response time tests practical upon j ccmpletion of plant construction. We find this comitment acceptable. g .,e 7.2.2 Ni e Containment Pressure Reactor Trip
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As has been t>e casa for recent B&W reactor designs, the RPS design has a primary trip- .U on Iow *eactor coolant systen pressure art back-up diverse trip on low pressurizer level. On the other hand, the ECCS desig*, which is also actuated by a low raactor -]'. coolant system pressure signal as a primary trip, uses high containment pressure as [ the diverse back-uo trio. I 7-1
E d Ct.o Sd M ~~2 D cm--A).s. 53-AGO 30 -5/] Jfm' $gfk op: ry}G~ &$t{tNGDA) YUCllDfL NY 'E 7.0 INSTRL' MENTATION AND CONTROLS i ' 7.1 General l i The Commission's General Design Criteria (GDC). IEEE Standards i including IEEE Criteria for Protection Systems for Nuclear Power I Generating Stations (IEEE Std 279-1971), and applicable Regulatory Guides fo-Power Reactors served as the bases for evaluating the j' I P adequacy of the protection and control systems. .f The review of protection and control systems was accomplished i by comparing the designs with those of the previously approved North Anna 3 & 4 and Bellefonte 1 & 2 facilities. l[ Our review concentrated on those areas'of design which are t 'l unique to the WNP-1, 4 for which new informatiot has been received,'
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. I, : er which have remained as continuir.g areas of concern during L. ^ this and prior reviews of similarly designed plants. --. . 9, l Re_ actor Prctection System (RPS) 7.2 i-e The WNP-1, 4 RPS design, designated as RPS-II, is a B&W 17 design now under review by the etaff..A minicomputer or "calcu-lating module" in each RPS channel is used to calculate a power If = 3'! h ! rip envelop)e. t It is the same design proposed in the Bellefonte ?; 1 application represents a basic departure from the North Anna 3 & 4 design, designated as RPS-I. RPS-II is described in B&W topical ,Q 44 report BAW-10085. and represents a new approach to RPS design in ,,h $1 that digital computer modules are used in each of the four RPS ,g ch mols. Total system acceptability is conditional pending .
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N'Y ~ /> h $5A $5 - 4!oc BJCfoSuf 5 o -57 3 3 A P ( 4 completion of our review of this system, which completion is. planned prior to the time of FSAR submittal on this application. I in the event The applicant has made the commitment that 1! '- f that we do not app. rove RPS-II by the time of the FSAR submittal, )- an RPS design will be provided such that it will achieve at least g'; the same degree of safety that is provided by the previously l 4 ;. 'f,.l reviewed and accepted RPS-I design. We consider this commitment 4, " acceptable at the construction permit stage of our review. i c I The RPS-11 design provides for reactor trip on pressur.zer level as well as a diverse reactor trip on low reactor coolant 4 The ECCS, on the other hand, is actuated by low pressure. reactor coolant pressure and high containment pressure signals, I s The staff's position has been that since a reactor trip is 'l l assumed in tht: analysis of DBA performance of the ECCS, the The same signals actuating the ECCS should trip the reactor. t applicant maintains that a low pressurizer level trip in RPS-ll, h, in lieu of a high containment pressure trip will provide an o equivalent degree of assurance that the reactor will trip prior .r to, or concident with, the time assumed in the accident analysis A / to be performed at the FSAR stage of review. The applicant has requested approval to retain the option to modify the reactor protection system design to include a high containment pressure-signal to trip the reactor, if it cannot be demonstrated at 4 i the FSAR stage of the review that the pressurizer water level s l l l
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~ E~lJCl.05tJW $ i a-L 4- [ We require that the successful completion and documentation of the remainder of the testing be a prerequisite to the awarding of a We further Construction Pennit to any applicant referencing B-SAR-205. require that an explicit interface requirement be added to B-SAR-205 indicating the above requirements must be satisifed in the applicant's l PSAR. 7.2 Reactor Trio System (RTS)_ The B-SAR-205 RTS design, designated RPS-II, is a new concept utilizing a minicomputer or calculating module in each RTS channel for calculatin RPS-II is presently under generic review by the a power trip envelope. staff in conjunction with the review of B&W topical report BAW-10085. It represents an entirely new approach to RTS design by virtue of intro digital computer modales in each of the four RTS channels and remains outstanding item for B-SAR-205 pending the evaluation of topical report BAW-10085. We have reviewed the RTS design as presented in section 7.2 of B-SAR and have found the associated interface requirements to be acceptable for the design as presented. This, however, is subject to change We shall require, pending the evaluation of topical report BAW-10085. consistent witn similar reviews, that should the RPS-II review fail to reach a timely conclusion (i.e. prior to FDA docketing) or should the design be found to be unacceptable, a proven design with similar functional capabilities must be substituted in order to prevent delay in Based upon the above, we do not feel that the PDA should ? the FDA review.
ENM uasi. 'f a op z. 5- ,/ 7 y be withheld pending final resolution of the generic review. We shall I include the results of our completed review in a supplement to this J report. 73 Engineered Safety Features Actuation System (ESFAS) j The ESFAS is the portion of the plant protection system that initiates s action of various ESF devices to mitigate the consequences of design basis 3 events. The system initiates the following functions: 1. Emergency core cooling injection, secondary system isolation and y cooling (ECCI), and phase A containment isolation. ? N 2. Feed only good generator (F0GG). 71, l I j 3. Phase B containment isolation and cooling (CIC). A J 9 4. Containment spray (CS). j .h The B-SAR-205 scope of the ESFAS includes all sensors, electronics, 3 signal processing equipment, and cabling from the system sensors to ~ the input terminals of the final actuating devices, e.g, motor controllers, l l 'lq For ECCI initiation, the ESFAS monitors reactor coolant and containment ,4 { pressure to detect loss of integrity of the RCS boundary. In addition, 'j it monitors the steam line pressure of,both steam generators to detect 1 ! loss of secondary system integrity. Upon detection of out-of-limit I j conditions of these variables, the ECCI initiates high-and low-pressure injection, isolation of main steam and main feedwater lines, the start 1 i of auxiliary feedwater pumps, and phase A containment isolation. 'J
tm.LUSURE o PRO?CEED BEAR-205 SER MATE 9!AL 7.2 Reactor Trip System The BSAR-205 Reactor Trip System design, designated RPS-II, uses a mini-computer or calculating module in each RTS channel for calculating five of the eleven diverse trip functions. B&W submitted topical report BAW-10085 4 " Reactor Protection System", June 1974, on the RPS-II. That report was superseded by a revision in March 1975. The system represents a new approach, using digital computer modules in each of the four trip system channels. We have reviewed the design as presented in Section 7.2 of BSAR-205 anJ have found the associated interface requirements to be acceptable for the design as presented. \\ We expect that any necessary changes in interface requirements that we might identify at the completion of our review of the RPS-II topical report (expected by September 1977) will be of a detailed design type which can be resolved during review of the first operating license application to reference the current BSAR-205 document. Our review of the RPS-II system as presented in the Babcock and Wilcox topical reports, and the commitments by B&W in response to our questions and positions, have progressed to the point where we consider that the design of the RPS-II meets our preliminary design requirements for the BSAR-205 review. We have concluded that there is reasonable assurance that further requirements which might evolve from completion of our review of the B&W topical report description of RPS-II, and from our review of
. - page 2 individual applicants' utilization of the system, can and will be effectively resolved on a generic basis with Babcock and Wilcox and in the review of individual operating license applications. ( 1 l l
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