ML20004E415
| ML20004E415 | |
| Person / Time | |
|---|---|
| Site: | Midland |
| Issue date: | 04/29/1981 |
| From: | BECHTEL GROUP, INC. |
| To: | |
| Shared Package | |
| ML20004E411 | List: |
| References | |
| NUDOCS 8106120155 | |
| Download: ML20004E415 (166) | |
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3 4 i . 5 . 6 7 r 8 9 PRESENTATION TO THE UTILITY DESIGN AND REVIEW BOARD 10 DESIGN TO ACHIEVE AND. MAINTAIN COLD SHUTDOWN 11 WEDNESDAY, APRIL 29, 1981 12 HELD AT: BECHTEL POWER CORPORATION OFFICE ANN ARBOR, MICHIGAN, 8:30 A.M. .. 13 14 , VOLUME I 15 r 16 17 18 19 20 i 21 22 23 24 i - ;iURON REPORTING SERVICE 4 - 761532s glo(ol _Ol5 [ 2
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I l 1 Ann Arbor, Michigan i 2 Wednesday, April 29, 1981 l i . 3 At or about 8 :30 A.M. - 4 5 MR. COOK: ft's my under-6 standing that everyone who should be here or wanted to 7 be here is here and that being the case, I think we . g Will Convene this session and get the proceedings under-9 way. My name is James Cook. I am the Vice President for Projects Engineering and Construction for Consumers Power Company. N-I'd like to welcome you all to the First Design Review Board Meeting for the Midland Project, the subject of which is to review the Midland 14 Project design on cold shutdown. I think it's appro-15 priate, before we begin into the detai?.s of the design 16 review, to have a few introductory and welcoming re-17 marks. I think the first thing I would note is that 18 i we do have a recorder with us this morning and we will 19 be making a transcript of this proceeding. Therefore, 20 I would ask everyone of this large group that's going 21 to participate, when you speak, please identify your-22 self to assist the recorder in making the best 23 24 i HURON REPORTING SERVICE 761 5328
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r I transcript possible. 2 The second item of introduction, I 3 would like to introduce the Design Review Board, 4 welcome our colleagues from the Nuclear Regulatory 5 m mission and ask them to introduce themselves, and
-6 then I will also ask Ed Hughes, who is the chief 7 spokesman for the group presenting the design to the -
8 Board, to introduce those that will be talking during 9 the course of the day. 10 I have just introduced myself. I am 11 serving as the company's chief representative on the 12 Midland Project as the Chairman of this Review Board. 13 Serving with me today and around the U-shaped table,
.14 starting at that end, I see Dick Loos, who is the 15 Bechtel Chief Nuclear Engineer; next to him, Eugene Van Hoof, who is Consumers Power Director of Nuclear 16 ,
17 Juel but is a long-time participant in the Midland g Project and prior to that in the Navy Nuclear Program. Next to Gene we have Jerry Slade, who is the Plant 19 Superintendent of the Midland Nuclear Plant and is 20 g currently at work on the site on the myriad of activities required to prepare the plant staff for operation of the plant when it is completed. 24 HURON REPORTING SERVICE 76b5328
I Next to Jerry is Ron Bauman, who is 2 serving as the Design Production Manager on the Nuclesq 3 Project directly involved in the Consumers Power 4 Engineering effort for the Midland Nuclear Plant and 5 one of the veterans of the design of the Midland 6 Project. Next to Ron is John Garrick, Principal of 7l P ickard , Lowe and Garrick, one of the leading con-8 sulting firms in the nuclear industry, who is working 9 as a consultant to the Midland Project nd one of his 10i principal duties is working with our engineers to 11 1 develop a probabilistic risk assessment for the 12 Midland design. 13 Next to John is Jim Taylor, Manager 14 of Licensing for Babcock and Wilcox, the supplier of 15 NSSS for the Midland plant. Next is Lou Gibson, 16 who is one of the principals in our Safety and 17 Licensing Engineering Operation for the Midland 18 Project. On my right is Terry Sullivan, the Manager 19 of the Safety and Licensing Department for the Midland 20 Project, and if I look over my list, that is all of 21 the Design Review Board Members who are present. We 22 are missing one other member who, due to an unfortunata 23 accident and incapacitation because of an injured foot, 24 ! i I. l HURON REPORTING SERVICE 7615328
1 can't be with us this morning. That is Russ Dewitt, > 2 who is Vice President of Nuclear Operations for 3 Consumers Power Company. He sends his regrets to the 4 Board and hopes that any further participation on this
.c issue he'll be able to directly contribute. That is 6 the constitution of the Board.
7 Darl, as the NRC Project Manager 8 for the Midland Projects, I would like to ask you, g please, to introduce your colleagues with us today. 10 MR. HOOD: Thank you, Jim. I 11 My name is Darl Hood. I am the Project Manager , l 12 assigned to'the Midland Project for the Nuclear 13 Regulatory Staff and I have four members from the Nuclear Regulatory Commission present today and I'd , 14 15 like to ask each of them in turn to introduce them-selves and name the branch organization of which 16 they're a part. 37 I MR. SULLIVAN: My name is j g Ted Sullivan and I'm with the Auxiliary Systems j ; 39 i Branch. i 20 MR. ANAND: My name is Raj Anand and I'm with the Chemical Engineering Branch. 23 _5_ 24 i HURON REPORTING SERVICE 7615328 i l
l MR. JENSEN: My name is 2 Walter Jensen and I'm with the Reactor Systems Branch.
.i 3 MR. MAZETIS: My name is 4 Gerry Mazetis and I'm with Reactor Systems.
5 MR. COOK: Thank you. I 6 would now like ti ask Ed Hughes, Assistant Project 7 Engineer on the Midland Project Team at Bechtel, to 8 please introduce the participants in hic group that 9 will present the design to us today. 10 MR. HUGHES: All right. 11 Thank you, Jim. I'm going to go through a little 12 brief introduction and then getanwith the . introduction 13 of my people here. As I believe you're all aware, the 14 purpose of this presentation is to provide a means for 15 expediting the licensing review of the Midland Project 16 by reducing the number of MRC questions produced during 17 the docket review; in addition, to demonstrate a 18 ! critical evaluation on the present design by this 19 Review Board. One of the ground rules for this 20 presentation is that, it being transcripted as Jim i I 21 said, we ask that anybody who is asking questions or 22 respond'ng to questions, please itentify yourself first 23 and if you're referring to figures or tables, to give I 24j 1 0 1 i i
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1 the numbers of the figures or tables. 2 In the format of this presentation,
. l 3 we are going to go through setting the stage of the 4 past and the present design and then getting into con- (
l 5 formance to regulatory positions and deal with 6 accident analyses and demonstrate the capability for 7 cold shutdown. Now, as part of our presentation, John 8 Gunning, whose licensing presentation on the history of 9 the plant and will also get into accident analysis, 10 and John is sitting over here. Mike Gerding will 11 address the control systems aspects of the accident 12 analysis. Tom Ballweg and Mike Pratt will address the 13 -- cover Section IV, which is the cold -- again, the 14 cold shutdown design of the systems. Bob Schomaker P 15 from B & W will address the accident analyses or 16 Chapter 15 events. 17 Now, as part of the ground rules for this, we do request that as we go through this agenda 18 jg -- John, will you put the agenda up -- that you hold . y ur questions until the end of part four, at which 20 g time we will have set the stage of what the preceding design and the present design is. Thereafter, 22 questions as you see fit. 23 24l , HURON REPORTING SERVICE 761 5328 m~
1 We have two people who will be record-2 ing any open actions ar.d at the end of this presenta-3 tion and question section, we will resolve and summarize 4 a list of the open items. 5 Now, just for history, for anyone who 6 isn't fully familiar, Midland is a project that started 7 over twelve years ago. A construction permit was 8 issued in Decenber of '72. The FSAR was submitted in 9 February of '77 and we've had two rounds of questions. 10 Essentially NRC review terminated after the Three Mile Island occurrence and since thi.c time we've had ex-12 tensive efforts underway on the project and with both g 37 B & W and Consumers to take the Midland design and con-g duct an internal review based on the lessons learned. 15
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three Company nuclear safety task force for which a g number of recommendations for design enhancements or improvements were determined and extensive on project g efforts using the industry-wide efforts of the Three Mile Island analy.3es. Now, we h7.ve updated the FSAR
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in October 1980 to include the responses to the 22 various Three Mile Island issues and events and any , i i i 4ssues identified prior to Three Mile Island. 23l 2 , HURON REPORTING SERVICE 7615328
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1 Now, a najor topic, the one for 2 discussion today, is the topic of cold shutdown and 3 this is discussed in the Midland FSAR text and the 4 responses to the various NRC requests. 5 At this time we'll start the presenta-6 tion. John Gunning, Bechtel engineer, will present
*i 7 the history and the preceding design, parts two and 8 three.
9 MR. COOK: Ed, excuse me. I 10 just wanted you to take care of the introductions. 11 MR. HUGHES: All right. , 12 MR. COOK: I had a couple of 13 other remarks to make before we got into the detail 14 presentations. 15 Ed has done a little bit of the 16 intr ductory remarks that I wanted to put on the record j7 and put before the group before we went forward, so I 18j will n t repeat some of the remarks that I had planned ' jgl that are similar to whathehad justdiscussed. I do think 20 it's w rth, though, to mention for all of the group g here and for the record that we are proceeding with 22 this Design Review Board basically as an experiment in 23 a me hanism to improve and to augment the licensing l 24j . . , HURON REPORTING SERVICE 7615328
r r 1 process. This idea was suggested to Consumers Power i 2 Company during a meeting last summer with Harold Denton 3 and other NRC staff management concerning the status of e 4 the Midland review and ways which we might explore to ( try to expedite that review in light of the constraints 5 6 fac d by tha NEC Ccmmission and its staff and also the f 7 problems being experienced by the applicant in trying to, you know, execute the job. 8 I think Mr. Denton made that suygestion ; 9 t for a number of reasons which he stated, but one of I t which I thought should be discussed at this juncture. ; I think it was his opinion as stated to us at that meeting that he had a concern that all utility appli-cants could profitably utilize this procedure to become 14 - more involved with their individual design. I think 15 i , one of the difficulties we have had in constituting 16 this Review Board was to find people who could be 17 sufficiently removed from the work that is being pre-18 sented to us here today to, you know, constitute an 19 : l independent look at that design. And I don't think that, ! 20' because of the nature of the involvement of everybody ; 21 l i i in this room in the Midland Project, that we have been 22 totally successful in being able to fulfill that i 23 24 , 9 HURON REPORTING SERVICE 7615328
1 particular philosophical attribute of a Design Review 2 Board.
/ -3 Be that as it may, I think we can 4 definitely proceed with this activity and make it
. 5 beneficial, but my general comment for the record was 6 that although it has been an evolutionary process 7 because of the long duration of this job, it is my -
8 firm opinion, and I think the opinion of all of those 9 who are part of this job with me, including the Chief 10 Engineer of my company, happens to be the President,
- 3) and the Chief Executive Officer, that all of us are 2
deeply involved in the completion of this project and 13 I think, although we will not burden the record with the 4 detailed discussion of how that has occurred over the y ars, it is there for those who are interested to pur-5 16 sue and to demonstrate to their own satisfaction that we at Consumers Power are fully involved in the job and will be in that role for the duration of the plant design and construction and for the, obviously, the 19 operation of the plant as it proceeds through its operating lifetime. < 21 l With regard to the format of this l 22 l meeting, we discussed the idea of constituting a 23 24 HURON REPORTING SERVICE 7615328
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1 Design Review Board, you know, with the staff after the 2 suggestion that we might find it useful. It was made to us by Mr. Denton. The culmination of that discuss:. )n ; 3 4 was transmitted to the staff in my letter to Mr. Denton f January 21, 1981, and that letter sets out basically 5 the protocol, you know, for the operation of this Review 6 Board and I might just touch on one or two points in 7 , that protocol as we start the meeting. 8 g I think the most important thing to touch on was the fact that we are pleased to have with O us today and participating in the discussions, although , not directly, members of the Design Review Board, the NRC staff members, you know, who are here. We welcome their presence and we encourage their comments and discussion, and we sincerely hope that their participa-15 tion and our detailed preparation of material for this 16 design review will be beneficial to the staff in 17 developing the detailed review that they need to do to 18 complete their review of the Midland FSAR. And as Ed 19 alluded to, we will caucus at the end of this meeting. 20 We will ask for staff, you know, comments on the 21 materials that they have heard and we will also develop 22 a specific list of things that we will follow up on 23
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i l 1 as part of the design review process in completing the 2 particular review of cold shutdown here today. 3 I think one other thing in terms of 4 introduction that we should touch on as we go by, I am 5 pleared that the staff was able to visit the Midland 6 plant site yesterday and that we also have another 7 meeting on another topic, although there is some inter-8 action between the two topics, scheduled for tomorrow. 9 However, in terms of trying to condttet a specific 10 review on cold shutdown, I will ask all of us to try 11 to focus our remarks today on the specific scope of 2 inquiry on cold shutdown, mainly because we have a 13 great deal of information to cover and if we start to range into other topics that are too far afield, I'm 14 n erned that we will be unable to complete our total . 15 agen a day. 16 g Obviously we will try to address, some time in the course of our activities, either in g this week or in future days, all of the concerns that g any of the staff members here today may have, but I will try to keep us focused specifically on cold : 21 shutdown today in order that we may try to get through our total presentation and question period. 24 . HURON REPORTING SERVICE , 761 5328 m -w - - ==
1 There have been advance materials sent 2 to both the staff members and all of the Review Board 3 Members discussing the materials to be presented today. 4 In addition, there is, I am told, considerable detailed 5 engineering doeunentation regarding all of the subject 6 under discussion today here in the room with us, so if , 7 you do not see enough detailed information, either 8 board members or staff members, to satisfy your ques-9 tions, we can make that available to you on short notice 10 during the proceedings here today. 11 Now, I believe that's everything I wanted to introduce as part of the introductions. Ed,
. 2 13 I'd like to turn it back to you, please, to start the 14 presentations.
15 MR. HUGHES: Thank you, Jim. For the first presentation, John Gunning, Bechtel 16 17 engineer, will present part two, the history, and part three, the preceding design for Midland plant. 18
!!R. GGNNING: Thank you, Ed. ;
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20 g consideration of plant design. However, the design l requirements for what is considered to be a safe shut- 1 22 down condition have evolved over the years. Emphasis 24 HURON REPORTING SERVICE 7615328 i
1 has traditionally been placed on the reactor condition 2 following a loss-of-coolant accident or LOCA. This 3 accident requires the use of emergency core cooling ! 4 system equipment. This presentation will not address 5 the LOCA to a great extent. However, equipment may be 6 used that's also used for emergency core cooling. 7 For non-LOCA events, then, the reactor ' 8 coolant system integrity is maintained. Achieving a 9 safe shutdown condition while the' reactor coolant 10 system integrity is maintained will be the primary 11 focus of this presentation. Following this type of 12 event, the stable condition to be maintained has been 13 hot standby. Hot standby.is a condition, safe, stable 14 e ndition that can be maintained for a period of time 15 without offsite power. Subsequently emphasis was
, 16 placed on insuring that all necessary equipment to 37 achieve this condition is safety grade.
18 :4 re recently, a similar emphasis was 39 placed on insuring that systema necessary to go to 20 e ld shutdown are safety grade. This emphasis, then, g on grade of equipment that is used in achieving cold shutdown has evolved from the change in the safe shut-down condition from being hot standby to one that is 24 ' i l HURON REPORTING SERVICE 761 5328
I cold shutdown. 2 Since we'll be using the terms hot 3 standby and cold shutdown extensively throughout this 4 presentation, I'll find it useful to define these terms 5 at the beginning. Slide III-1, this slide III-1 is a I 6 figure that correlates with this presentation the 7 various shutdown conditions with reactor temperature. - 8 Hot standby is a condition from reactor trip down 9 to the reactor coolant system temperature when the 10 decay heat removal system can be initiated. 11 After a reactor trip, the temperature 12 is at the high end of this range and will stay above 13 the hot zero power temperature. Hot shutdown, then, is 14 from the decay heat removal cut-in temperature and down 15 to a reactor coolant temperature of 200* Fahrenheit 16 and cold shutdown condition is from 200* Fahrenheit 17 and below. 18 Associated with this is the reactivity, i 39 where the reactor is at least one percent Delta k/k subcritical. The event useful for evaluating the 20l l 21 plant shutdown capability is the safe shutdown earth-22 quake coincident with loss of offsite power. Other 23 events will be addressed in Section V. 24l l HURON REPORTING SERVICE 7615328
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'l From a historical. p.rspective, after 2 Three Mile Island occurred, a nuclear safety task force' 3 was formed and recommendations issued. Most of the 4 design upgrades concerning cold shutdown that have beer 5 incorporated into the Midland design have evolved from 6 this effort of the nuclear safety task force.
7 In conclusion to the section on 8 history, present Midland design basis is that hot 9 standby is a safe shutdown condition. This design 10 basis is appropriate because hot standby is a safe, 11 stable condition that can be maintained for an extended 12 Leriod of time with a minimal amount of operator action . 13 Therefore, it provides additional time to further B 14 evaluate the condition of the rea: tor. In addition, 15 it frequently is preferable to me.intain the reactor in 16 this hot, stable condition for extended periods of time 17 rather than subjecting the plant to an immediate cool-18' e u ren dland design provides for 19
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- 20 means, the hot standby condition following an SSE or safe shutdown earthquake c> incident with loss of off-site r. 4 c. Although it's not a design basis, present 24 l i
l i HURON REPORTING SERVICE 7615328 l
1 Midland design incorporates the ability to take into 2 cold shutdown condition using only safety grade equip-ment, assuming only onsite or offsite power is avail- : 3 4 able and considering a single failure. 5 In addition, the present Midland l 6 plant design can achieve and maintain cold shutdown 7 following a tornado by using equipment that's protected . from the effects of the tornado. This is conclusion of 8 g Section II. I jg p Progressing now to the preceding design, it's appropriate to briefly review the Midland 33 nu lear steam supply system. I'm sure some of you got a 12 chance to see the hardware of that on your plant review yesterday. Slide III-2 is a pictorial' review of the Midland reactor coolant system. It's a B & W nuclear steam supply system. Could you focus that perhaps a little? The reactor vessel, the two steam generators, the pressurizer, four reactor coolant pumps, two hot legs and four cold legs. This is figure II;-2 or slide III-2. 20 Slide III-3 is a schematic from the 21 same system. It shows the two steam generators, the - 22 two hot legs, four cold legs, four reactor coolant 23
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1 pumps, and slide III-4 is a view of the steam 2 i generator. Thank you. 3 The remainder of this presentation 4 will provide an explanation of the preceding design 5 and is intended to facilitate an understanding of the g I design upgrades that have been made. It's been pre-7 viously stated the Midland design basis has been the , 8 ability to achieve hot standby using safety grade g systems. It's previously shown, in figure III-1, hot standby is a range but normally after a reactor trip, 10 the reactor coolant temperature will stay at the 3 upper end of this range. This condition can be main-2 tained using safety grade equipment with sufficient time to re-establish offsite power and then use safety grade and non-safety grade systems to maintain hot standby and to proceed to cold shutdown. In order to insure this stable con-17 dition is maintained, certain essential functions nust 18 be performed. These essential functions are reactivity 19 control / inventory control grouped.together as one, 20 pressure control and heat rejection. These functions 21 are performed by particular systems and consequently 22 necessary systems will be addressed on the appropriate 23
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1 function that the system performs. 2 Slide III-5 will address reactivity 3 control / inventory control. Control rods: Control rods . 4 are -designed to bring the reactor to at least one 5 percent Delta k/k subcritical upon reactor scram. 6 Allowance in the design is made for the highest worth
/ control rod assembly sticking out of the core as well 8 as for the temperature effects from hot full power, 9 579, to hot zero power, 532. ,
10 Boration of the reactor, boration 11 concentration in the reactor coolant system is normally 12 increased by using a makeup system, makeup pump,to 13 inject boric acid from the chemical addition system. , 14 In the event chemical addition system 15 is unavailable, boric acid from the safety grade 16 borated water storage tank may be injected into the 17 reactor coolant system. Regarding inventory control, the makeup system normally controls the reactor coolant 18 system inventory. Obviously we here see the obvious 39 l interrelationship between inventory and boration con-20 g trol. Portions of the makeup system are 22 safety grade and used for high pressure injection to 23! 24 , HURON REPORTING SERVICE 7615328
I assure adequate core cooling and appropriate boron l i : 2i concentrations. Makeup water is again available from 3 the safety grade borated water storage tank. 4 Pressure control, slide III-6: III 6, 5 pressurizer safety valves, this is a pressurized steam I 6' generator,ree: tor vessel, the reactor coolant pumps and 7l the safety valves. Pressuri=er safety valve prevent i 8 over-pressurization. In the event of loss of offsite 9 power, the thermal inertia of the pressurizer maintains 10, the reactor coolant system pressure sufficiently until 11 the pressurizer heaters can be re-energized. 12 Slide III-7, heat rejection, the hot 13 standby condition: Heat removal is accomplished 14 using the steam generators, the main steam isolation 15 valves and main feedwater isclation valves, main feed-16 water not being shown, main steam isolation 17 ralves. These valves may be closed to limit secondary 33 side heat removal. In addition, the main steam isola-39 tion valves and main feedwater isolation valves close 20 automatically on low steam pressure or after receiving 21 an emergency core cooling actuation system. These 22 valves limit secondary side heat removal if required. Auxiliary feedwater enters here. A motor driven and a 23 241 ! I i l H' IRON REPORTING SERVICE 7st5328 , 1
I turbine driven auxiliary feedwater pump are supplied 2 with cross connects on the discharge so that either 3 pump can feed either or both steam generators. 4 Normal auxiliary feedwater is from 5 condensate ' storage tank. However, emergency backup 6 is provided by the safety grade service water system. 7 Main steam relief valves: Heat re-8 moval rates to maintain the hot standby condition can 9 be maintained by cycling the main steam relief valves. 10 Steam removal without cycling these relief valves could 11 be performed by mpening the non-safety grade modulating i2 atmospheric dump valve. This valve has since been re-13 located and will be discussed in the present design section 14 The one other concern in heat removal 15 addressed is natural circulation. This is to insure 16 that if heat removal was being removed from the 17 secondary side, that adequate core cooling is also being 18 maintained. Midland plant can provide adequate core jg cooling without operation of the reactor coolant pumps. 20 Characteristics of this natural circulation cooling have been calculated by Babcock and Wilcox with con-21 l 22 servative values for their resistance and form loss f ac to L's . 24 l l HURON REPORTING SERVICE 7615328
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i 1 i With this I conclude my section on I f i ! ' 2 i the preceding design and I turn it to Mike Pratt who ' i
- 3 I will now address the beginning of Midland present 4 design capability. 1 i ,
5 MR. PRATT: Good morning. My; ! 6 name is Mike Pratt and I will address several important 7 aspects of the present design capability for cold shut-8 down. First a few general comments; the Midland design 9 provides for the ability to achieve and maintain hot , 10 standby following a safe shutdown earthquake with loss 11 of offsite power. Although not a design basis, the 12 Midland design incorporates the ability to be taken to 13 the cold shutdown condition assuming only onsite or 14 ffsite power is availab'e and considering a single 15 failure. Could I get the first overhead? This 16 was touched upon briefly in John's discussion. Re-17
- g. activity and inventory Control, pressure control and heat rejection are the essential functions that must 39 be considered. I will address reactivity / inventory 20 and pressure control, the first two items, and Tom Ballweg will then address heat rejection.
22 Figure IV-1B shows the operational 23 24 HURON REPORTING SERVICE 761 5328
I temperature ranges for reactivity arxi inventory control 2 systems. Shutdown functions and systems are shown on 3 the left and the operability of those systems over a 4 given temperature range is depicted by horizontal bands 5 or whichever is appropriate for the given system in 6 question. Specifically for reactivity and inventory 7 control, control rod operation is shown, operability 8 range of the emergency boration system is shown and 9 operability ranges for reactor coolant makeup from the 10 BWST and from the chemical addition system are shown. 11 There are three aspects of reactivity 12 in inventory control; control rods, boration and RCS 13 makeup. Control rods were discussed.previously and
- 14 no design changes have been made in this area for cold 15 shutdown so I'll move onto the second item of boration.
16 For normal shutdown reactivity control, the design of i
! the Midland plant includes two sources of borated 17 i
18 water: First, the borated water storage tank or BWST 19 and, second, the chemical addition system or CAS. 20 With let down available, either the BWST or the 21 chemical addition system is capable of maintaining 22 the reactor to one percent subcritical. This can be during hot shutdown or transition to cold shutdown at 23. l 24 i HURON REPORTING SERVICE 7615328 l i
I any time in core life for the most limiting normal , 2 fuel cycle. This is assuming xenon free conditions 3 and the maxi.num worth rods stuck out of the core. 4 The use of only safety grade equipment . 5 to maintain the reactor suberitical at hot standby and l 6 the transition to a cold shutdown condition requires 7 the use of the emergency boration system or EBS, and 8 the overlay shows the addition of the emergency boration g system providing a suction source to the u' ::eup pump. ( 10 The EBS is a safety grade system 33 designed to provide a six weight percent boric acid 12 solution to the RCS by the makeup and purification 13 system. The EBS in conjunction with the other con-14 traction volume sources is designed to insure the ability to maintain a one percent subcritical margin 15 l during hot standby and during the transition to cold 16 I g shutdown. Adequate shutdown margin is maintained dur-P ing the transition to cold shutdown by using the 8 g borated water from rhe BWST or chemical addition ; system. The next overlay shows that suction source i 20 capability. f These sources provide adequate com-pensation for reactivity changes that result from the 24 i L HURON REPORTING SERVICE 7615328 l
1 change in moderator temperature. Following any event 2 which results in loss of letdown and a stuck rod, the 3 six weight percent boric acid solution from the EBS 4 storage tank can be transferred to the RCS via the 5 makeup and purification system. One of the three 6 makeup pumps is used to inject this solution into the 7 RCS. - 8 What I'll do now is go onto the third 9 aspect of reactivity / inventory control, specifically 10 inventory control. As the RCS cools, it is necessary 11 to keep the volume of water in the RCS approximately ! 12 constant. Therefore, additional water is injected via 13 the makeup system. The safety grade source of makeu'p 14 water is the BWST or borated water storage tank. This 15 tank contains at least 300,000 gallons of 1.3 weight percent boric acid solution. In addition, three boric acid 16 , addition tanks per unit, which are part of the non-17 g safety grade Chemical addition system, are al3o avail-3g able for makeup. These tanks can provide the required RCS contraction volume in conjunction with other avail-20 , g able water sources. The boric acid addition tanks are - tornado protected and can be made available following ! a tornado and a loss of offsite power. 24 1 i b HURON REPORTING SERVICE 76b5328
1 emergency DER system cut-in temperature and is intended 2 for use only during emergency cold shutdown. The 3 auxiliary spray system flow is provided by a makeup 4 pump. Suction for the makeup pump is normally taken 5 from the BWST. The boric acid addition tanks via the 6 makeup tank. serves as an alternative suction source. 4 7 The spray line discharges to the auxiliary DHR 8 pressurizer spray upstream of parallel motor-operated 9 globe valves so we have the auxiliary spray connection being 10 made at tbis point tying into the normal auxiliary 11 spray line. And by the way, this is figure IV-3 of 12 the controlled shutdown document. I 13 The spray system requires local align-j4 ment prior to initiation but is remotely initiated and 15 controlled from the control room. Once initiated, the 16 spray will be operator-controlled to provide the 37 desired depressurization rate that is determined by ; the cooldown rate and plant status, 18 jg The design enhancements for pressure control, which I touched on briefly a minute ago, are 20 g shown on figure IV-3. This includes the addition of the auxiliary spray capability from the makeup pump and 22 also includes the addition of a second PORV block valve. i 24 , HURCN REPORTING SERVICE 761-5328
1 That concludes my discussion of re-2 activity and inventory control and Ton Ballweg will 3 now discuss heat rejection. 4 MR. SULLIVAN: Mike, can we 5 ask some questions on reactivity and inventory while i I 6 you're still up there or do you want to wait? 7 MR. HUGHES: Terry, I'd - 8 really prefer to finish with Tom, if that's all right, 9 and then we'll go into questions on that, unless it's 10 a matter of clarification for the upcoming -- 11 MR. SULLIVAN: I can wait. MR. BALLWEG: My name is Tom Ballweg. I will be talking here today about the 13 heat rejection part of the cold shutdown. Thus far, Mike Pratt has discussed reactivity and inventory control systems and pressure control. In this portion, I will talk briefly about the specific Midland plant features and systems used for heat rejection and to maintain control of the reactor coolant system tempera-ture. In the first transparency, our first transparency, which is figure IV-lc of your pack, basically covers the material that I will be talking about here today. 22 In heat rejection, the steam generator 23 24 l l l l
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1 HURON REPORTING SERVICE i 761 5328
1 is initially the primary path for release of energy. 2 The necessary operational parts of the system are the 3 main steam isolation valves and the main feedwater 4 isolation valves to establish the pressure boundary on 5 the steam generators. The auxiliary feedwater system 6 is operational through the entire range of hot standby 7 down to the hot shutdown condition. The main steam 8 relief valves provide capability for heat rejection 9 initially on hot shutdown -- or achieve, excuse me, 10 hot standby and are operable by cycling above those 11 temperatures. The power-operated atmospheric vent 12 valves are used to reject heat from the normal hot 13 standby condition on down to the hot shutdown condition, 14 The decay heat removal system is used after the reactor 15 e lant system has been cooled to either 325* , or in the 16 case of an emergency cooldown, or to 280' normally. 17 ti w I'll go into a little more in-depth 18 discussion of the heat rejection using the steam 3g generator. The next slide is figure IV-5. Basically to reject heat Via steam generator, it is necessary to g provide a source of feedwater, source of water, the ; l aaxiliary feedwater system and the steam vent path. The steam is vented either via the power-operated 24 i HURON REPORTING SERVICE 761 5328 ~
I I atmospheric vent valves or the safety valves or the 2 mcdulating atmospheric dump valves. The features which 3 are in red here are enhancements or modifications made 4 specifically to handle or to facilitate the cold shut- , 5 down. , 6 The main steam relief valves are il 7 spring-loaded valves and cycled to relieve steam 8 enabling the reactor to be maintained in a hot standby l 9' condition. The power-operated atmospheric vent valves, 10 there are actually two, although we're only showing one 11 per steam line, provide a path so that steam can be 12 relieved to maintain the reactor in a hot standby con-13 dition without cycling the main steam relief valves. 14 Steam can also be relieved to cool the reactor to the 15 temperature where the decay heat removal system can be 16 cut in. 17 The power-operated atmospheric vent 18 valves are safety grade, motor-operated control valves , 19 1 cated, as shown on the figure, upscream of the main j 20 steam isolation valves. , 21 POAV's are sized so that an inadvertent stuck open valve will not result in unacceptable con-2i sequen es to the reactor core. The PCAV's are sized 23
! 24it i HURON REPORTING SERVICE 7615328
l I to permit the reactor coolant system to be cooled to 2 the emergency decay heat removal system cut-in tempera-3 ture of 325' within thirty-six hours, assuming one 'l; 4 operational POAV per steam generator. The 325* cut-in ; i 5 on the DHR system I'll talk about a little bit later. 6 Each POAV can be manually -- can be i
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7 jog-controlled from a switch in the main control room j 8 or from a switch at the auxiliary shutdown control 9 panel. Th'.s operator will position the POAV's until an ! 10 acceptable temperature is maintained or an acceptable , l 11 cooldown rate is established. 12 Steam relief.- can also be accomplished 13 by dumping steam to the condenser or opening the 14 redulating atmospheric dump valves. These valves are 15 located downstream of the main steam isolation valves 16 and would be used preferentially in a cooldown, in a 17 normal cooldown over the POAV's. However, to insure 18 that cold shutdown can be achieved using only onsite 19 emergency power and safccy grade systems, credit is 20 only taken for the components upst e x of the main
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21 steam isolation valves. Figure N-7 shows the discharge of 22 the auxiliary feedwater system. The auxiliary feed-23 water is automatically supplied to the reactor coolant j 24i l 1 l l l HURON REPORTING SERVICE 761 5328 ~
f I i 1 to the steam generators at a controlled rate by re-2 dundant one hundred percent capacity pumps. One of the , pumps is a motor-driven pump. The iother pump, the f 3 4 B pump, isasteamturbine-drivenkump. Power and 5 controls to both pumps are safety grade and Class lE. I I 6 The next slide, which is figure IV-7, 7 shows the suction side of the auxiliary feedwater 8 system. The normal alignment of the auxiliary feed-g water system is to the condensate storage tank and through two normally open motor-operated valves which 10 allow suction to both main feedwater -- excuse me, ! both auxiliary feedwater pumps. Safety grade source of auxiliary feedwater is provided from a service water system independently for each auxiliary feedwater pump. Because of the concern for the quality of steam generator feedwater, automatic transfer to 16 service water is provided only upon coincident AFW actuation signal and low auxiliary feed pump suction pressure. Now I've completed the discussion 20 that I will about the auxiliary feedwater system and the heat rejection using the steam generators. What 22 I'll talk about now is the decay heat removal system. 23 24 HURON REPORTING SERVICE 7615328 :
t I l , After the decay, after the reactor- ! 2 coolant system pressure and reactor coolant system hot 3 leg temperature have been reduced to approximately , 4 300' and 280' Fahrenheit, or 325' Fahrenheit under , l 5 emergency conditions, the DHR system operation can be-l l i 6 gin. 7 The previous design-directed that until ' . 8 i the DH -- that the DHR system would not - s operated 9 until the reactor coolant system hot leg temperature 10 was decreased below 280 Fahrenheit. The DHR system 11 has been analyzed to evaluate operation at 325' and 12 found acceptable. The higher DHR system cut-in tempera - 13 ture permits operation of the DHR system within thirty-14 six hours, assuming operation of one POAV frcm each 15 steam generator. 16 J hn could I have the second slide back on, SC? One of the enhancements to assure 17 a hievement of cold shutdown is the addition of a 18 jg parallel bypass motor-operated valve inside the con-tainment on the DHR letdown line. Though not shown 20 g here,, there are actually two valves in series where ne is shown. These were installed so that a single 22 failure of the valve to open will not inhibit the 24 HURON REPORTING SERVICE 7615328
I flow path for DHR cooling. 2 The next part of this presentation i 3 will deal with reactor coolant system natural circula-4 tion. The Midland plant has been analyzed to insure 5 that natural circulation will occur during a cool two 6 loop reactor coolant system cooldown without using 7 forced circulation. ; 8 In addition, a natural circulation l 9 cooldown test will be referenced if a similar test has ! l 10j not been conducted on a plant similar to Midland. If , 11 such a test is not available, a test will be conducted l 12 to verify that operation of the POAV valves,and under 13 natural circulation will satisfactorily remove heat 14 from the reactor to cool down the plant. The test 15 will cool the reactor coolant system approximately 50* under- natural circule. tion conditions. The data will 16 37 be used to verify adequacy of prior analytical *esults., p, Another modification that was made to g in part enhance natural circulation was the auxiliary , feedwater level Control. The auxiliary feedwater system g and, in particular, the auxiliary feedwater level con-trol will be the subject of a discussion to be held
, tomorrow. The details of that system are not addressed l
24 l j HURON REPORTING SERVICE 761 5328
t I here. However, the system will include safety grade ! 2 automatic control of steam generator water level. i
-t ~
3 Steam generator water level is normally maintained at 4 a constant level of about two feet when there is forced l 5, circulation in the reactor coolant system. If zero or ;
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6 one reactor coolant pump is operating, the auxiliary j 7 feedwater level control system and level rate control 8 system will ramp the feed, auxiliary or steam generator g level at a rate of about, currently, around four inches 10 per minute from the two foot set point up to the twenty ij foot level set point that's desired for natural cir-12 culation. The automatic transition from the lower 13 water level to the higher water level in the steam 14 generator provides an orderly transitior and reduces 15 the probability of overcooling of the primary loop. Now, that's the end of my remarks. 16 Back to you, Ed. 37
)g i MR. HUGHES: All right. ;g Thank you, Tom, and onpartof the members of the Review ;
Board, thank you for your patience in listening to these !
,0 4
formal presentations, but the purpose of this was to create for the record, and to provide a basis for a l review, the history of the plant, the preceding design 24 l HURON REPORTING SERVICE 761 5328
I as we've characterized it and the enhancements to 2 achieve cold shutdown that we've added to the Midland ,. 3 plant for the consideration of the requirement that 4 cold shutdown with safety grade means must be provided ; 5 for Midland. 6 With that formality out of the way, 7 I will go ahead and entertain any questions that you ; 8 desire relative to the presentations. I would ask you g to recall that we do plan further presentations in the 10 course of this on cold shutdown versus Chapter 15 type 11 events and cold shutdown versus fire and a comparison 12 f the present design with applicable regulatory guides , 13 so those presents.tions will be given after this series . 14 f questions and appropriate questions on those are 15 perhaps delayed until after you hear the presentation. M . IBSON: Just a couple of 16 points of clarification. Figure IV-2, there's referenc e - 37 g to chem addition tank. Am I correct that we don't have jg -- we have a chem addition systen but we do not have chem addition tank? We have boric acid addition tanks? MR. PRATT: That's correct, 21 Lou. 22 MR. HUGHES: That is correct. 24 HURON REPORTING SERVICE 761 5328
~ :: : : . - . . . - - , - , - - --,
1 MR. GIBSON: Okay. Also, just 2 for reference, on some of the slides and drawings that C we've seen, there are a number of valves shown as whau 4 I call plain gate valves, just a straight cross. Is it 5 true that not in all cases are those manual or was 6 there an attempt to make every one of those accurate - ; 7 or was it only to highlight the valves that were im- - 8 portant to the discussion, because it seems to me, if g we wanted to go back and get a real, true picture from 10 these slides, we'd have to go to the P&ID, am I - 11 MR. HUGHES: I believe that is correct, that these are strictly pictorial for the 2 purp ses of discussion and do not attempt to include 13 all valves or the mode of operation of each valve or 14 15 the type in any particular case. The P&ID's which ave een shtted are de detailed documents as to 16 g valve type and we can get any discussion that you care
# ' 8" # # E * *" "~
18 tions for function. MR. GIBSON: Thank you. MR. TAYLOR: On a couple of 21l figures, the operating range for suction from the BWST 22 or the chemical addition system is shown to end at 24 l l HURON REPORTING SERVICE 761 5328
1 280. Why does that not go on down to lower temperature? MR. HUGHES: Basically I 2 3 believe the 280 is strictly a nominal cut-in temperatur e,- 4 required cut-in temperature for tha decay heat removal 5 system and this really wasn't intended to show the l 6 ccmplete range of system operation. Mike Pratt, do you have anything . 7 8 further to add to that? MR. PRATT: Yes. I think 9 10 y u're referring to figure IV-1B -- MR. TAYLOR: Correct. 11 MR. PRATT: -- which shows 12 the makeup from BWST and chemical addition system g extending to the normal decay heat removal cut-in temperature of 280. I guess that was only an extension of that point for purposes of illustration. Makeup, makeup is certainly possible. MR. TAYLOR: On down? 18 MR. PRATT: On down. 19. MR. TAYLOR: One other point 20 of clarification. On one of the slides that you 21 showed, the connection between the new auxiliary spray 22 line and the existing spray line from the reactor l 23 24 HURON REPORTING SERVICE 7615328
1 coolant pumps, those valves were shown as manual valves. , 2 Are they really manual valves? 3 There's a line in the existing spray 4 line, I think it was on figure IV-3. The makeup - 5 the line coming up fror the reactor coolant pump into l
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6! the pressurizer, is that truly a manual valve there? 7 fir. PRATT: There is a manual 8 valve in the line but there are also parallel sole-9 noid operated valves. I do have another overhead that 10 shows the detailed design, but there is not just a i 11 single manual valve in that line. 12 MR. TAYLOR: There is no 13 need, then, to go inside the containment to realign g any valves if you go into the auxiliary spray mode? ! MR. PRATT: No.
!G. HUGHES: That is correct.
gl MR. GIBSON: Could we see 18 i g tiR. COOK: It's in the packet. Figure number IV-4 I think is the one you're alluding to. MR. CIDSON: Oh, okay. i 22 ' MR. PRATT: Would you like to 24 ! l' I l HURON REPORTING SERVICE 76b5328
1 see that up on the - 2 MR. COOK: Why don't you go 3 ahead and do it. 4 MR. PRATT: Up on the screen 5 and walk through it? 6 MR. TAYLOR: Okay. So IV 7 is just a very simplified version, then, of IV-47 . 8 MR. PRATT: That's correct. l g MR. HUGHES: That's correct. 10 MR. PRATT: We have the
;j normal RCP discharge going in through the spray valves 12 into the pressurizer. We have the existing or pre- l 13 existing decay heat removal auxiliary spray capability 14 f r cooldown mode and then the design feature that was 15 added was the supply from makeup pump discharge into the existing line with the addition of motor-operated 16 gl be valvas for throttling during the depressurization 17 sequence going on into pressurl=er spray. 1 18
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19 20 MR. HUGHES: It's depicted there just as the L's. MR. TAYLOR: Could you point 24l l l HURON REPORTING SERVICE 761 5328 l l 1
1 on figure III-2, which is the physical arrangement . 2 showing the spray line, where that connection is betwee'n i y 3 -- or where it is likely to be between the new line and 4 the existing spray? 5 MR. PRATT: Dc you have that 6 in John's package? Now, could you repeat the question?' 7 MR. TAYLOR: Where is the 8 new connection from the auxiliary spray going to tie i g into that large two-and-a-half inch line, the spray line? 101 11 MR. PRATT: All right. That would not be shown on this drawing because that Connection is outside the containment. MR. SLADE: It has to tie 14 into the spray line. MR. HUGHES: The question is where, physically -- MR. SLADE: But where does 18 auxiliary spray tie into the pressurizer? g MR. HUGHES: With the spray line coming off the loop. MR. PRATT: We have the 22 existing spray line coming off the reactor coolant 23 24 ... HURON REPORTING SERVICE 761 5328
l pump discharge and coming into the pressurizer. 2 MR. TAYLOR: Yes. Now, the i 3 auxiliary spray line connects into that line somewhere. t 4 MR. PRATT: Yes. 5 liR. TAYLOR: And I'm in-6 terested in knowing where it is. Is it right close to 7 the pressurizer or down close to the reactor coolant l 8 system or just where? 9 MR. PRATT: Well, that I am 10 afraid I can't answer. We can get the isometrics and 11 take a look at those, but I'm not sure exactly where it 12 ties in. 13 MR. HUGHES: Jim, we can get 14 you that information in the course of this review, but 15 right now we can't provide it to you exactly. 16 MR. TAYLOR: Okay. 17 liR. HUGHES: You're talking 18 about the piping isemetric location to tap into the 19 auxiliary spray, I believe? 20l MR. TAYLOR: On a broader 21 basis, what I was really getting to is what kind of g - this auxiliary spray was an addition to the plan 23 and I'm interested in the kind of review that was i 24 ! HURON REPORTING SERVICE 7615328
I conducted on the existing system as a result of that 2 addition because this is a much lower temperature than 3 normally is seen by that line. 4 , MR. HUGHES: Are you talking, 5 for instance, the stress analyses, the thermal , 6 cycling? 7 MR. TAYLOR: Right. ' 8 MR. HUGHES: Mike, you can 9 address that, I believe. 10 MR. PRATT: Okay. Yes, we 11 were using the existing line from the decay heat re-t 12 moval system and the complete stress analysis has not
. 13 been completed. It's in progress at the current time, 14 but that kind of design concern has been taken into 15 account in that we're subjecting a pre-existing section 16 of the piping to a different set of flow / temperature 17 conditions, pressure as well.
18 MR. VANHOOF: Didn't the ; I 19 auxiliary spray line from the decay heat removal systed 20 exist before and that the makeup, the line from the 21 makeup system was the one that was added? 22 MR. PRATT: Right, it was 23 added. 24
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. j i HURON REPORTING SERVICE 761 5328 1 i
1 MR. VANHOOP: So wasn't that 2 analyzed and reviewed prior to this change? 3 MR. PRATT: It was analyzed 4 for the decay' heat removal function. 5 MR. VANHOOF: And that's the 6 temperature you're concerned about, is it not, Jim? 7 MR. TAYOR: I'm sorry. I 8 didn't hear the last part of that question. 9 MR. VANHOOF: The decay heat rem val spray line existed before. The only change 10 that was made was a discharge from the makeup pump 33 system into the spray line to give you that capability. 12 S the temperature analysis, I think, was done prior 13 g to this. MR. PRATT: It was done prior 15 i to that for decay heat removal operating conditions, MR. SULLIVAN: Yes, the g suction would make a difference in the temperature, though, of the spray because you're taking it from the g BWST or whatever rather than returning it from decay 20 heat removal system, so it's not necessarily the same ! temperatures. , 22 l MR. VANHOOF: But you could 23 24 ! I HURON REPORTING SERVICE ' 76b5320
I take a suction from the borated water storage tank with 2 the decay heat removal pumps as well? 3 MR. SULLIVAN: Yes. . 4 MR. VANHOOF: So I would thint 5 that the temperature for that situation would also be 6 analyzed. . s 7 MR. HUGHES: Well, the pre- , 8 existing condition was analyzed and we are in the , 9 process of analyzing the operating conditions for this 10 condition. 33 MR. COOK: Can we simply have 12 a discussion of the criteria that you're using for that jg analysis and where your temperature interfaces are? l 14 MR. HUGHES: I believe so. f ,3 MR. FRATT: Okay. Let's go ; back to the previous figure. Yes, that's the one. , 16 g That's the one, okay. I, to go back to a point you . 18 I BWST or chemical addition system was a design basis , 19 1 for the decay heat removal auxiliary spray. I think [ 20 i F that operating condition is decay heat removal once it's -- I believe once it's gone through the cooler. . 22 ' I'm trying to remember where the connection is, but I t 23 24 ~47- \ l I HURON REPORTING SERVICE [ 7615328
1 don't believe that that operating mode would be taking 2 suction from the BWST for chemical addition. 3 MR. SLADE: I think, just a 4 point of clarification that may help here is that 5 Previously when we were talking suction from the decay [ 4 6 heat removal system and using the decay heat pumps to 7 forward spray to the pressurizer, by the time we could - l 8 cut-in decay heat removal, we were down to very low g temperatures in the pressurizer, so you didn't have the 10 thermal problem that you now have when you're trying i 11 to provide that same cool water at normal operating pressures in the reactor coolant system. 13 - 11R . PRATT: Right, that's g correct. Now, as fitr as the design conditions, the normal reactor Coolant pump discharge to the pressurize c spray would be analyzed for cold leg temperature 6 g pressure conditions. MR. TAYLOR: As an action item, I would like to see the before and after design g conditions for that portion of the line which is affected by this change. MR. PRATT: Okay. Let me try to clarify that; temperature, pressure, number of 24 HURON REPORTING SERVICE l 761 5328
. . - - ._ ~ . . _ . . --.. .. - - - . -
1 cycles? , 2 MR. TAYLOR: Right. 1 3 MR. PRATT: Okay. The first .. 4 two -- MR. HUGHES: We'll go ahead 5 6 and take that as an open item to provide that information. I 7 MR. GIBSON: As long as we're on this topic, I had a question concerning the 8 g use of the makeup pump when you're trying to run water , through the auxiliary spray. It seems to me that that 10 3 jj would be a very low flow rate compared to the minimum 2 requirements that that pump can put out and that brings 13 up a question of what are you doing with the recirc and are there any assumptions that you have to make g relative to loss of any recirc Capability under those Conditions? What do you postulate as the worst case, conditions that the makeup pump may have to have g relative to its recirc back to the makeup valve? Is 19 MR. PRATT: Okay. Well, there were a number of questions -- MR. GIBSON: I know. 22 MR. PRATT: -- included in 23 what you stated. I believe the first one was how do HURON REPORTING SERVICE 761 5328
1 we handle the makeup pump minimum flow requirement, 2 which is 100 gpm and that is handled by a recirculation i 3 path to the borated water storage tank in the event 4 that we're taking suction from the borated water storage tank and the recirculation path would be to the 5 makeup tank in the event that we were taking suction 6 7 from a boric acid addition tank. a MR. GIBSON: Is that < 8 manually aligned to the BWST? 9 I MR. PRATT: Yes, it is.
,JI MR. GIBSON: So using the j) auxiliary spray, you would use either one of those I paths that was available, is that correct?
MR. PRATT: That's right. 14 MR. LOOS: With respect to 15 the recirculation flow back to the makeup tank, how 16 is that aligned and what is the valve configuration? 17 MR. PRATT: Well, the normal 18 recirculation flow path during makeup operations is 19 to the makeup tank, so the same piping and valve 20 alignment and configuration is used for that that is
- 21 used for normal makeup.
22 MR. LOOS: And what is that 23 24 4 HURON REPORTING SERVICE 761 5328-
1 valve alignment? 2 MR. PRATT: That would involve 3 opening two solenoid operated valves in the recircula- -; i 4 tion line. 5 MR. LOOS: In series or i 6 parallel? 7 MR. PRATT: In series and 8 depending on which makeup pump you were using, you'd 9 need to tie the makeup pump discharge into the common 10 recirculation header. 11 MR. VANHOOF: I've got a couple of questions for you, Mike. On the PORV, what 12 ,. 13 kind of indications do we have off those valves now? What is it, a positive type indication or a passive? - 14 15 MR. PRATT: Indication of
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16 E*" j7 MR. VANHOOF: Position.
)g MR. PRATT: Position?
I
)g! MR. VANHOOF: Yes.
MR. PRATT: tee me -- 2g MR. HUGHES: Mike Gerding 21 w id probably be a better one to ar.swer that. This 22 is really in our area of control systems and the 23 24 HURON REPORTING SERVICE 7015318
1 provisions we are making in the PORV. 2 MR. GERDING: The indications 3 that would have a positive, we have Class lE limit l 4 switches on the solenoid valve which is seen in 5 figure IV-4 and in addition from tdun discharge of thst l 6 valve, there is an acoustic monitor which is also 7 safety grade which monitors flow in that discharge - -{ 8 line. , 9 MR. VANHOOF: Said you have 10 very brief switches -- [ gj MR. GERDING: Yes. MR. VANHOOF: -- which are 2 dependent upon valve movement in order to actuate? 13 MR. GERDING: That's correct.
)4 MR. VANHOOF: So that would 5
be a positive, in addition to the acoustic line? g MR. GERDING: That's correct. MR. VANHOOF: Okay. I have another question, Mike. MR. GIBSON: Can I follow 20 that up? MR. VANHOOF: Oh, fine. 22 MR. GIBSON: Mike, does that 23 241 l I HURON REPORTING SERVICE 7615328 l 1
1 mean that when you get a stem movement that you see 2 with those switches, that that valve has to be moving
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3 or can that be a pilot or something else that's moving? i MR. GERDING: It's actually 4 the valve, itself. There's a stem inside tha valta 5 i which moves and is detected by -- it's, I believe, it's 6' 7i a magnetic type reed switch in the valve, itself. . t1R. GIBSON: But is it , 8 g possible for that to move and the valve to stay closed r f r the valve to. stay open and that move back closed? 10 MR. GERDING: No. 33 MR. HUGHES: Mike, I believe the question is, is it a direct connection to the 13 valve disk, itself?
. : s not 15 exactly a direct Connection. As I mentioned, it's operated magnetically in this particular valve design.
MR. GIBSON: Thanks. 18 MR. SULLIVAN: While we're 19 in that area, though, you had, on figure IV-1A, the ,o s set points. Can you explain a little bit the logic on block valve isolation and the set point there? 22 It says the block valve will close automatically on 24 HURON REPORTnNG SERVICE 761 5328 i
1 coincident indication,the PORV not shut and 2100 psig. 2 First of all, what's the pressure that the FORV should 3 close automatically? 4 MR. PRATT: You mean open? 5 MR. SULLIVAN: No, should l i 6 close. I assume it's opened aircady. You've reached 7 the 2260. Now you're coming down in pressure. 8 MR. PRATT: Okay. 9 MR. SULLIVAN: In other words , i 10 how far below the point at which the PORV should have jj closed automatically is that 2100 psig? 12 MR. PRATT: Mike, do you -- 13 MR. GERDING: Okay. The , 14 reset set point for the valve when the pressure 15 decreases after the valve is open is currently 2235 16 p unds per square inch. 97 MR. SULLIVAN: Okay. So y u've g ne through a transie..it. You've hit the high 18 g pressure crip set point and, if not, something else. Th reactor has tripped. If the PORV opened, you're O coming back down, you pass through the -- what did you say, 2235? liR . GERDING: That's correct. 23 24 1 i HURON REPORTING SERVICE 7615323
I MR. SULLIVAN: The PORV, for 2 some reason, stuck open and you reached 2100 psig. Now 3 you've got one part of your signal that the PORV is 4 stuck open. What other indication, then, are you 5 using, which of the two indications or both are you 6 using as an indication that the PORV is not shut, 7 besides the pressure indication? , 8 MR. PRATT: Valve position f 9 indication. 10 MR. SULLIVAN: Okay, and the 11 acoustic monitor, then, is strictly a backup for the 12 operator's information? 13 MR. PRATT: That's right. 14 MR. GERDING: The valve 15 limit switch, the PORV valve limit switch is used to 16 close one of the block valves coincident with the 2100 17 pound decreasing signal and the acoustic monitor is 18 used coincident with the 2100 pound signal to close 19 the other block talve. MR. SULLIVAU: Okay. So 20l 21 you've got sort of a combination of diversity and redundancy there? 22 MR. GERDING: Yes, that's 23 correct. 24! l 1 l i HURON REPORTING SERVICE 761 5328 l o _ . . _ . _
I
; MR. GIBSON: Mike, acoustie m nitor, sometimes acoustic monitors are flow monitors 2
and sometimes they're just microphones. I guess 3 they're all microphones but is this -- would you 4 haracterize this as a flow monitor? 5 M . : an say that ; 6 it detects the flow. The actual mechanism I't. not 7 familiar with. I would have to investigate that further and get back to you. g MR. COOK: Does that matter 10 interest you? MR. GIBSON: No. 12 MR. VANHOOF: Mike, on the 13 pressurizer heater, you say there's two banks that are 14 lE. As I recall, the breakers for those pressurizer 15 heaters were located in the lower level of the turbine 16 buildings. Are they still there or have the lE breakers 17 been moved; my concern being that in the event of a 2 18 j break in circulating water, that you'd have a flooding 4 19 condition in that area and you might lose those l 20 breakers. Where are tiey located now? 21 MR. PRATT: That I can't l 22 answer. I think John -- l I 23 24 HURON REPORTING SERVICE 761 53"*8
1 MR. KOVACH: The upgrade 2 included utilizing new Class 1E breakers from the 3 switch gear located in the safety switch gear equip- ; 4 ment room. 5 MR. VANHOOF: So you've 6 moved it out of the lower level of the turbine building? l 7 MR. KOVACH: We did not 8 Ph ysically move the breakers. We utilized new breakers in the Class 1E distribution system. 9 MR. VANHOOF: So breakers 10 11 are in the same location? MR. KOVACH: No, we are not 2 using the non-Class lE breakers with the previous desic n. 13 We are using new breakers from a Class lE electrical distribution system. 5 MR. SLADE: Those breakers 6 are still in the basement of the turbine building g but now they're enclosed inside a water tight enclosure, 18 ! i is that correct? ! 19 MR. KOVACH: Thev're in the 20 safety-related equipment rooms, yes. MR. VANHOOF: Thank you. 22 MR. HUGHES: John, what he 23 just said is that the old breakers are enclosed in 24 HUP R4PORTfNG SERVICE 761 5320
1 water tight -- 2 MR. SLADE: No, no, new ones. 3 MR. HUGHES: Okay, the new 4 breakers -- 5 MR. COOK: But they're i 6 Ph ysically at the bottom elevation of the turbine 7 building still? MR. HUGHES: No, we must for-8 9 get about the old breaker because they were non-lE. The new breakers are in a safety grade structure, not 10 in the turbine building, and they are the lE power 11 supply distribution to the pressurizer heaters. 12 MR. VANHOOF: Not in the 13 turbine building? g MR. BAUMAN: Seismic category t 15 16 MR. HUGHES: Right. g MR. BAUMAN: Gene, they're g not in the turbine building anymore, the new breakers g being used, fully safety grade in the safety grade building, right? MR. KOVACH: Correct. 22 MR. TAYLOR: I don't know 23 24 HURON REPORTING SERVICE 7615328
1 whether the other designer board members got that 2 clear or not, but I didn't. 3 MR. HUGHES: Essentially 4 when we went to lE requirements for heater banks five 5 and six, the old non-lE breakers were essentially 6 neglected. New lE breakers were placed in a seismic 7 and lE location. - 8 MR. TAYLOR: Which 157 9 MR. HUGHES: Which is in the --
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10 what is it - the safety equipment - l1 MR. KOVACH: The switch gear 12 room is in the aux. building. 13 MR. HUGHES: In the auxiliary 14 buildinr , the switch gear. 15 MR. SLADE: Okay, adjacent U ~~ 16 37 MR. VANHOOF: Adjacent to the turbine building? 18 I MR. KOVACH: Right. j 19 i MR. TAYLOR: So the old 20 breakers are no longer in the picture anywhere? 21 MR. KOVACH: Right, that is 22 rrect. 23 20 l l l HURON REPORTING SERVICE 761 5328
1 MR. VANHOOF: As far as the ! 2 pressurizer heaters are concerned, they're still there, 3 usable,but not for the pressurizer. 4 MR. SULLIVAN: Mike, as long i 5 as we're on this subject, can you give us a feel for 6 the basis for selection of this heater capacity? You 7 know, it was stated that the pressure control could be ' 8 maintained during hot standby or the transition to g cold shutdown using one of the banks. , , 10 MR. PRATT: That's right, 11 one. 12 MR. SULLIVAN: How many 13 kilowatts and how is that determined? 14 MR. PRATT: I cannot answer 15 Mat gesdon. 16 MR. BAUMAN: That analysis 37 was done for us by B & W to set the capacity of the 18 ea er an s, H someMdy can answer eat. jg MR. HUGHES: Jim Agar from 20
' I" * *
- Y E* "# #* * ^ "
- heater bank sizing?
MR. AGAR: I can speak off the top of 'ty head but rather than do that, I would 24 l *' l HURON REPORTING SERVICE 7615328 l ._ . - _ _ _ - _ - - -
1 take that as an action item to feed back to the board 2 the results of the calculations. 3 MR. BAUMAN: I recall a - 4 significant amount of discussion back and forth on that, 5 Terry. There was several inter-relations so that we i 6 were convinced that the sizing was proper. I don't 7 recall the details but I know that it was a subject of . 8 discussion. 9 MR. COOK: The open item to 10 the board, then, is the basis for the sizing to docu-11 ment the question. MR. SULLIVAN: Yes, because 12 13 as I recall -- well, we had started this before the TMI accident occurred and some of the requirements 14 15 after TMI -- there were talks about a number of banks but there really wasn't a basis for the sizing. 16 i MR. SLADE: I quess I'd like 37 t ust expand that just a little bit further and 18 gg you're identifying two banks and I am making an assumption that each of those banks is powered from a 20 separate power supply, is that correct, so that if we 21 lose either power supply, a single bank of heaters is all that's available to control pre,ssure' and that's 24 , HURON REPORTING SERVICE 761 5328
1 what we're concerned about establishing, that the out-2 -put of that bank is sufficient to maintain pressure? 3 MR. HUGHES: That's the 4 statement that's made, that one bank of heaters will - 5 do it and that's the size and basis but we'll supply 6l the particulars of the criteria and selection for i 7 sizing. _ r MR. VANHOOF: I would like 8 9 some clarification or perhaps some broadening of the reason for installing the emergency boration system. 10 I As I recall, the shutdown with rods, you can attain a 33 ne percent Delta k shutdown capability with rods most , 2 worth -- the largest worth rod being stuck out. Why was the emergency boration system added? Is this because of xenon or what?
* ' Y 16 you touch on that briefly and then Jim Agar from B &W can supplement it.
MR. PRATT: Okay. You can, with a highest reactivity worth rod stuck, you can achieve cold shutdown. It can achieve a one percent 4 i 21 cuberitical margin with letdown but in the event that 22 letdown is not available, the use of the emergency 23 24 1 HURON REPORTING SERVICE 76b5328
e 1 boration system is required. 2 MR. BAUMAN: But didn't it 3 also have to do with the fact that the chemical , 4 addition system was not fully safety grade or am I' 5 Wr0D92 MR. PRATT: Not fully safety 6 7 grade and the boric acid concentration in the chemical . addition system is three-and-a-half weight percent 8 g whereas the determination was made that a six weight jg percent solution is required for the emergency boration system. 11 MR. SULLIVAN: So if you can't let down from the primary system, then, you need a 13 higher concentration boric acid because there's not 4 enough volume in contraction there, is that it? MR. PRATT: Yes. I think, you know, a lot of the criteria for this aspect of the design of the emergency boration system were provided g by B & W and perhaps it would be better for some of the follow-on kind of questions, maybe to clarify something that I may have misspoken, to defer to
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B & W. 22
- MR. HUGHES: Jim Agar, do -e 23 24 HURON REPORTING SERVICE 761 5328
1 ycu have anything further to add to that? Gene's 2 question really was the basis for the emergency boration 3 systems and the response of ours, really the decision ; 4 use merg=.ncy boration is keyed to de availamhy
,. of letdown and the criteria for cold shutdown using a
g strictly safety grade equipcant. 7 MR. AGAR: That's correct. MR. GIBSON: I'd like -- g MR. SULLIVAN: Let me follow 10 s MR. GIBSCN: I'd like to 11 follow up. MR. SULLIVAN: Well, what's 13 the approxirate worth? It seems to me that a most 14 reactive rod stuck out is the key assumption here. 15 What's the approximate worth, say, for the first 16 quarter of the most reactive rod? 17 MR. AGAR: The way _ under-18 stand it is it varies with the operating condition 19 but I wculd let Rich Lange from 3 & W address this 20 question and he's the one who did the calculations. 21 i MR. LANGE: The worth of the 22 stuck rod is covered bf the control rod design. The control 23 24 ' i HURON REPORTING SERVICE 761 5328
~ - ,y _- - . - .- y y ---- -w
3 rod design compensates for the stuck rod and com-pensates for the temperature deficits reactivity in-2 sertions down to 532' for the fuel and the moderator. The purpose of the chemical addition, the use of BWST and the emergency boration system is strictly xenon, the build-up and decay of xenon. Within approximately twenty-two hours or twenty-three hours after reactor i 7 trip, xenon life level will have peaked and returned to its equilibrium value and then will subsequently decay. 9 . l So it's to compensate the xenon decay that the 10 emergency boration system was evolved. 11 Now, as far as the concentrations go, 12 the reason for it being six weight percent as opposed 13 to a number such as five, which a lot of plants have, 14 is related to the amount of storage volume that's 15 available and in order to design a new system and 16 accommodate the tanks, there was a limited spacing 17 available and so it was decided to go with six weight 18 percent. Originally it was thought to go with twelve 19 weight percent but it was felt that six would be better 20 if you can squeeze in a larger tank, and that was 21 subsequently the route that was taken. 22 MR. COOK: Let me tag along 23 24 ' I HURCN REPORTING SERVICE i 7615320 ;
I
- 1. on this. In terms of the interface between the 2 nuclear engineering requirements coming out of B & W 3 and the mechanical engineering requirements and syetem ,
4 4 design from Bechtel, do we have a design criteria that 5 is specified in terms of boron concentrations of the 6 primary system as a function of the various operating 7 conditions you have to deal with for this particular 8 application that has been transmitted to Bechtel to 9 e mpare y ur mechanical designs to -- how has that interface been covered?
);
MR. HUGHES: Mike, would you care to answer that? The question is ppm boron and who has told us. 3 MR. PRATT: The criteria for 14 a six weight percent boric acid solution, minimum 1800 gallons, was provided by B & W. MR. COOK: In just that basic set of criteria? 18 MR. PRATT: Well, there were other discussions. 20 MR. HUGHES: There have been 21 a series of meetings and discussions with B & W on the 22 sizing of the system and on our difficulties in space 23 24 i l l HURON REPORTING SERVICE 761 5328 I t
i 1 to come up with a suitable objective of parts per 2 million boron given the tank sizing, so we iterated 3 between the percentage and the gallons available to i 4 meet the B & W requirements of so much boron in there ! at a given time and volume of available -- 5 MR. COOK: Let me restate my 6 question, then. Where do we have.a performance 7 analysis of the system as it is currently designed for 8 g all the possible operating conditions that you might 10 exper ence a s e mpared t B & W's nuclear re W re-ments? 3) MR. HUGHES: Right. The-performance analysis is essentially one of B & W. Ours is a performance of a flow delivery. In the Bechtel calculations, we would analyze the flow rate, time, pressure, the performance of a mechanical 16
' system and it would be married to B & W analyses that with that performance and that concentration, that 18 much boron in the reactor provides a given reactivity 19 or reactivity margin.
20 MR. CCOK: I'd just like to 21 see the process, the system that says that, you know, 22 the engineering system that says that the performance 23 24, 1 l l
! HURON REPORTING SERVICE 7615328 1
1
/
P 1 of that system to carry out its design function has 2 been analyzed by the appropriate party in whichever 3 organization it has to be and that we have verified, 4 to the satisfaction of both organizations, that we 5 have met the intended function. i l l 6- MR. HUGHES: Let me take it 7 in a two-step, if you will, then, and Rich, would you 8 go ahead and give him a brief rundown on your design g analyses and then the providing of criteria to Bechtel? 10 MR. LANGE: The way we -- 11 MR. HUGHES: Excuse me, Rich. 12 You can come forward a bit to allow the reporter to 13 hear you. 14 MR. TAYLOR: While you're 15 g ing up front, Rich, one of the corollary questions to one of the questions Mr. Cook asked is are the g design criteria for the EBS documented in a specifica-8 tion which has been transmitted to Bechtel and are the g bases for that specification documented? MR. LANGE: Yes. They are documented in eighty-six internal documents that were sent to project management. Functionally, the way the system was designed was that we took the criteria of 24 HURON REPORTING SERVICE 7615328
i 1 compensating for xenon and based the design around the 2 ability to increase the boron concentration enough to 3 compensate for the burnout of equilibrium xenon. Okay, 4 that, as far as the particular mechanism, was then, as far as when you really need the boric acid to go in, 5 is based on a consideration of trips from equilibrium 6 conditions as well as double reactor trips. 7 g MR. GIBSON: I've been going
! over this, even before the board meeting today. One g
thing that strikes my mind that we should know is if we O have a normal reactor trip from, say, full xenon, we level out at 532, we haven't started the cooldown; do we need that EBS even without letdown? I don't 13 see why we need the letdown under those conditions yet
- anyway, frankly, but --
MR. LANGE: The control rod 16 design in compensating for the deficit size specified earlier is based on equilibrium xenon, so you will 18 have, under limiting conditions, you will have only one percent shutdown margin after xenon has peaked and 20 returned to equilibrium. If xenon continues to decay, 21 you will eat into the one percent shutdown margin. 22 MR. GIBSON: So you don't ) 1
. 23 24 HURON REPORTING SERVICE 7615328 l t _ - _
1 have to use that EBS until you're back to equilibrium 2 xenon? , 3 MR. LANGE: Yes, that's true. 4 MR. GIBSON: And that is with 1 5 one rod out? 6 MR. LANGE: With the most 7 worthy stuck rod out and in a most limiting fuel cycle with respect to shutdown modules. 8l 9 MR. SLADE: Let me go on just 10 a little bit farther from Lou's scenario there where ; I've tripped the reactor from equilibrium xenon and r 11 n w I've appr ached my peak and I'm ready to put the 2 unit back on line. Do I have a limitation at peak 13 xenon for need of that emergency boration system? Will g I still have adequate shutdown margin available to ne as I'm putting the unit on line? MR. LANGE: If you could 37 , 18 xenon, you're not in a limiting situation with regard g to shutdown margin provided by control rods. You didn't have any reactivity to insert in order to get the unit back up. This is predicated on not starting up prior to returning to equilibrium xenon because in 24 HURON REPORTING SERVICE 761 5328
1 a limitating situation, I don't think you can 2 physically do it. 3 MR. SLADE: I can't bring 4 my unit back on a peak xenon?
, aR. LAUGE: not if you re - l , xR. sLADE: certainly I can.
7 MR. LANGE: I don' t think if y u're in a limiting situation with respect to control 8 9 r d shutdown -- 10 that you have a rod out, stuck out, identified as stuck out and cuestionable. 12 MR. SLADE: No, no. Let me trace it again. I don't think we're assuming the same things. We're at equilibrium xenon, have a reactor trip. Everything is fine. I'm ready to start the unit back up again. Pull the unit critical by diluting the boron concentration, okay, so that at peak xenon, I now have rods out. I now have diluted the xenon 19 I and I'm starting -- or diluted the boron and I'm now l starting the reactor up. 21 Okay. Now, I have a trip as a result 22 of the safe shutdown earthquake or whatever, okay? Am 23' 24 I i l I l HURON REPORTING SEHVICE 761 5329
l I I ready? Do I have sufficient margin, and I think 2 what you're telling me is that I don't have the power 3 deficit to be concerned about and that that makes up 4 the difference, is that correct? 5 MR. LANGE: Well, what you 6 could not have done is dilute the system because if you! 7 were at a limiting situation with respect to shutdown 8 margin where you only had the one percent and -- I 9 MR. SLADE: I didn't have a 10 stuck rod yet. I didn't have a stuck rod until the
-11 second trip. i
- i 12 MR. LANGE: I understand, but '
13 in order to start the reactor up, a limiting situation : 14 is based on 17 ppm in the core and you simply couldn't 15 dilute enough to get back up to power under those 16 circums tances . So you couldn't have returned to power 17 by dilution. , 18 MR. SLADE: What you're tell-19 ing me, then, is the limiting situation is end of core 20 lif*? 21 MR. LANGE: Yes, with respect to -- 22 MR. SLADE: And under those
. 23 24 ll HURON REPORTING SERVICE 761 5328
1, circumstances, I couldn' t start the - 2 MR. LANGE: Yes. 1 3 MR. SLADE: - unit back up 4 again because I couldn't dilute the negative boron? 5 MR. LANGE: That's right. 6 MR. SLADE: How about earlier in ( 7 core life? - 8 MR. LANGE: Yes, you could l 9 dilute to start back up. - 10 MR. VANHOFF: Same situation jj and he trips that. ; 12 MR. LANGE: But he doesn't 13 . have a one percent. He's got more than one percent on 14 the control rods now. 15 MR. VAlmOFF: With one controd. r d sWck out? 16 51R. LANGE: Yes. 37 ; r 18, MR. SLADE: So what you're l i ! jg telling me is that as long as I can meet my tech spec rg emen s n n r w awa at de power ; 20 g level at which I am at, that I'm going to have : I sufficient margin? 22 1 MR. LANGE: Yes. 24 HURON REPORTING SERVICE 761 5328
1 MR. SIADE: Regardless of 2 what the xenon concentration may be? 3 MR. IANGE: Yes. 4 MR. SLADE: Okay. Now, in 5 conjunction with that, we were talking earlier about , 6 how much baron I have to add to the system or how l 7 quickly I can add the boron to the system in the event . 8 of this incident, okay, based on inventory control. 9 If I'm at peak xenon and I am losing reactivity or l 10 gaining reactivity as a result of that loss of xenon, 11 is there sufficient volume available in the RCS to inject the boron under those conditions? 2 13 MR. IANGE: I may have lost the precise conditions regarding your question in that 14 last paragraph, but what we based it on is being able 15 to utilize volume in the pressurizer and Cooldown g volume between 579' and 532' -- actually that's 542' -- 18 , g able to get enough boron in to reach the required conditions so it's -- the analysis we did is based on really available volume. MR. SLADE: But available . 22 volume based on equilibrium xenon conditions, not 24 ~74~ l l HURON REPORTING SERVICE 761 5320
1 based on peak xenon conditions? 2 MR. COOK: Let me break in 3 for just a second. I think we've gotten off on a vary 4 detailed line of questioning that's going to be difficuit 5 to resolve in this particular forum. If I can try to 6 come back and summarize where I think this line of 7 questioning has gone, first of all we were interested - 8 in making sure that we understood that the detail re-
<2 quirements from the nuclear engineering aspect, the 10 B & W side of the house, were fully documented 11 through the project process to the architect engineer 12 and that there was a full interface review to make 13 sure that all the conditions that we're required to 14 make were specified and understood by the designers 15 and that there was some check that that had been verified. I think beyond that you've gone into some 16 additional thoughts on the operating possibilities of 37 3g that system that you're interested in, and rightly so, from an operating point of view. )
39 i wu suggest that by pulling out ' 20 g of the system the documentation, you know, that specifies all the conditions that were utili=ed in sp ifying that system and in designing it, you and 23 i 24 HURON REPORTING SERVICE 7615328 w---, , ,-- ,--,-w
1 your operating people should review that very carefully 2 to make sure your questions have been answered in 3 terms of, you know, your considerations on plant 4 operation. Is that a fair statement in the way we 5 ought to proceed to try to move on? l 6 MR. SLADE: Okay. I guess I 7 need to have more data on the background, the assump- - 8 tions that were used in calculations so that we can 9 do that review. 10 MR. LANGE: I might add one 11 point. I.think the thrust, I think I've gotten the 12 thrust of your question. It is based on equilibrium 13 xenon, not greater than equilibrium xenon; the reason 14 being, in a limiting situation, not being able to 15 start up before you get back to equilibrium xenon, so 16 that in a nutshell is the philosophy that we've used. 37 MR. BAUMAN: What we need is gl a set of criteri: in design assumptions that B & W gg used in your analysis so we can make sure that all 20 plant operating conditions have been factored into your analysis. We need the input to your analysis, the basis of your analysis for our review. 22 , I don't think we have that now. All 24 HURON REPORTING SERVICE 7615328
1 we have is the numbers that B & W gave to Bechtel as ' 2 far as the percent boron and the volume, but what were 3 the assumptions that went into that analysis? That, ' 4 I think, we need and I don't think we have that, do we? I 5 J1" A98#2 l l 3> MR. AGAR: We have formally _ 7 transmitted a document around to Consumers and Bechtel , L 8 that give thebases and backgrounds and the calculations i g that Rich Lange has completed. You should have that , 10 document and perhaps that's the one you can review to 33 get at least a good start in response to that question. _ r 12 MR. SULLIVAN: I guess where , 3 we're at, though, now is Jerry, you need certain data 1 in order to develop your normal operating procedures and emergency procedures? i 16 MR. SULLIVAN: And what you would usually do is take that document, review it and , see if there is enough information there for you to develop your procedures. If not, then you would ask j for additional analysis or whatever .d I guess the question would be, are you at that point already where 22 , you are developing t. lose procedures or is that some 3 HURON REPORTING SERVICE l 761 5328 I
1 point in the future and are we jumping ahead of our-2 selves? 3 MR. SLADE: The answer to 4 your question is we're beyond the point. The procedures 5 are already developed and what I need to know is , 6 whether I need to change the basis on which those 7 procedures were developed. Is there going to be a 8 revision to the operating spec as a result of this g B & W document and the bases, have they changed the assumptions that were in the original operating specs 10l that were provided to Consumers. 33 MR. HUGHES: Jim, the original 2 Perating specs provided to Consumer did not envision 13 the emergency boration system at the time. MR. AGAR: That is correct, 5 ves.
^
16 MR. HUGHES: Therefore, yes, there will eventually be further information and con- ! sideration. , 19 MR. AJAR: This would also 20 be a consideration of an emergency procedure and the use of the emergency boration systems will have to be, 22 I assume, written up. To my knowledge, you haven't 23 --
~7E' 24 HURON REPORTING SERVICE 7615328 -
, = ..
I 1 written that emergency procedure, is that correct? 2 MR. S LTSDE : No. Our pro-1, 3 cedures do not yet include consideration of the 4 emergency boration system. 3 MR. AGAR: That's the word 6 that I got back yesterday and I understand that from
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7 Mr. Ivan Green, Dr. Ivan Green, who is on the 8 committee for reviewing these operating procedures, g and we'll get into that chain of review at that time, 10 I would guess. 11 MR. HUGHES: Jim, the origina l 12 question -- 13 MR. COOK: Excuse me, Jerry. 14 Go ahead. 15 MR. HUGHES: -- was the basic design process and we had gone through Mr. Lange to 16 identify the B & W analyses that went into it. Should 37 4 We go on further for the board to where the architect r 1g engineer comes in? Do you have an answer to your question as you originally posed it? MR. COOK: I have an action item but I didn't have an answer. 22 MR. HUGHES: That's correct. 23 24 HURON REPORTING SERVICE 761 5328
1 MR. COOK: With your under-2 standing of what the action item is, we can go on with 3 it. 4 MR. HUGHES: We have received 5 from B & W documentation as to the requirements for 6 this system and as the architect engineer we have 7 designed a system we believe meets that requirement 8- for delivery of a volume of borated water to the g reactor under given conditions and we have reviewed those with Consumers Power and with B & W, a series of 10 11 meetings, and are now presenting this in this form for
-- as a new system which has been added to achieve cold 2
shutdown under given conditions; namely, without let-13 14 down. MR. COOK: Where is the 15 heck that says B & W certifies that the system you 16 have designed meets all the requirements that they 17 have established for this sytem? Is that in the 18 record already?
)g
* ^ * * ""
20 reached that point of complete confirmation. We have some calculations thac are ongoing. Apparently there's-
. 22 some stress calculations within Bechtel that are still 23 24 HURON REPORTING SERVICE 761 5328
.s_, _ _ _ _ _
No 1 ongoing and I would guess that in the very near future i
- 2 we should have full agreement between the architect 3 engineer and the NSS supplier with regard to the EBS, 4 the emergency boration system.
5 MR. COOK: I think, with the i 6 condition that everybody is sure that all of the 7 operating situations that have to be looked at have -f 8 been looked at as far as establishing the criteria, 9 that would satisfy my original question. I think the . r 10 other half of the discussion that we went onto was the , 11 operating side of Consumers Power Company is interested 12 in making sure they understanding all those operating i 13 conditions and can review their procedures and require-14 ments and what they have to do to get ready to operate
- 15 the plant to make sure they understand it and have it 16 totally integrated into their work.
17 MR. SLADE: Yes. Jim, I'd 18 like to go one step beyond that and asrure that we are 19 g ing t receive operating specificatior.: for the , emergen y boration system and the affects on the other
- 20 t
21 perating specifications which we have already received .. MR. BAUMAN: Jim, it goes 22 f farther than that. In the total cold shutdown package, ; 23 24 , l HURON REPCRTING SERVICE 761 5328
I 1 there are a lot of interfaces with the operators and I l 2 would suggest that we consider strongly an operating l
.r 3 guide and an emergency spec for the entire cold shut- !
l 4 down package. You just talked the one system here but j l 5 as you go through the B & W analysis and the Bechtel i 6 analysis, you'll see where there are a lot of areas !
'L 7 that will require close operator attention and I think, 8 as a total package, we need to develop an operating spec 9 and an emergency spec.
10 MR. GIBSON: One final point, 11 I have observed, looking at the EBS, since it is a i 12 manually aligned system, I think B & W should be very 13 careful on just telling us how soon it's needed. I > 14 say that because I envision a lot of the loss of let-15 down events as being temporary. There are a lot of j things that can kick that off and then you can restore 16 it, and I think if you have an accurate picture of how 37 soon you need that EBS, you may find the prudent 18 jg course of action is to have that letdown system back so you don't just arbitrarily have that thrown in right 20 g away and assume that the letdown is going to be re-turned. 22
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MR. HUGHEIS: ,Again, the EBS 22 24 . HURON REPORTING SERVICE 7615328
t 1 is a system provided for given circumstances as a ! 2 -- let me scy an emergency procedure, and the whole r i
.L 3 question of emergency procedures is handled in the ,
I l 4 course of getting the plant on line and, yes, the ! 5 design information we provided in whatever form, the 1 i l 6 utility operating department requires it, but for the - l i 7 course of this presentation, this really isn't a - i L presentation on procedures except as it explains the g 9 peration of the system and the designer's intent for [ r capabilities, so I believe offline from this forum, 10 gj we can provide this information as it's needed. Is I r that satisfactory to the board? We have normal 2 i procedures in effect for doing this, in the course of ( 13 exchange of information with B & W and with Consumer engineering and do involve Consumers' operation in 5 this, I believe. MR. LANGE: Ed, just to address that last point, that was a consideration in , the design, which is basically why it's manual as opposed to automatic, and the time requirement is that the system is not required before two hours, so we did
~. 21 try to take that into account.
22 MR. HOOD: Could I ask 23 24 HURON REPORTING SERVICE 761 5328
1 Mr. Slade, if he would, to identify the document from 2 B & W to which he earlier referred? ! 3 MR. SLADE: I'm just trying I 4 to get the right number on it. I guess it's identified L 5 as Consumers cold safe shutdown and the number on it ! 1 6 is 86-1123863-00 and it's dated February 11, 1981. l 7 MR. GARRICK: I would like to 8 make a comment and then ask a couple of questions. : On the same sub-9 MR. COOK: 10 ject or a new one, John? i MR. GARRICK: Well, it in-11 { -- 3 volves -- it will come to this same subject but it's 12 13 more general and then I was going to converge on a couple of specific items. l 14 MR. COOK: Okay. Why don't { 15 ! we p int it towards convergence. j 16 I MR. GARRICK: All right. 17 Okay, well. let me talk, then, specifically about the 18 39 emergency boration system because as I hear you talk, ; 20 it sounds like -- that there has been an attempt here f I 21 to get considerable credit for this system and as it's t presently designed, it, of course, requires local, 22 manual peration. I wanted to ask -- and, therefore, 23 24 l HURON REPORTING SERVICE 761 5328
- - - ~ _ - _ - . . _, _ _ _ . . _ _ . . _ . _ _ ,
1 it's a slow-acting system, at least relatively speaking. , 2 I wanted to ask if the specification for the system 3 does talk to the time constant for the use and effective-4 ness of this system. How slow acting is this system? 5 MR. HUGHES: Well, as stated, 6 the system is not required for, by calculations, for 7 two hours. Therefore, we believe that the manual r e alignment of the system is appropriate for a system 8 f 9 whose need is in that time frame. MR. GARRICK: Was there any 10 consideration given to itr. utility if it were available s er than two hours? 2 MR. HUGHES: For the design, 3 1 it being an add-on system, it was answering a need 14 rather than looking as an integrated package as to all possible functions it might perform. It was rather a -- what basic need does it require and what is required to provide that need. Therefore, no, it was not examined 18 as far as other potential where we were starting from an earlier phase. 20 MR. GARRICK: So I take it 21; from that that the isolation valves, consideration of 22 motor operated isolation valves and control from the 23 HURON REPORTING SERVICE 7615328
1 control room was not something ya21ooked at? 2 !iR. HUGHES: We looked at it 3 originally in the system as to whether it was required 4 and when it was determined it wasn't required, then a i 5 decision was made that we would not provide them. , l ' 6 Based on the stage of design of the project, any
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7 additions to control room are additional design 8 problems relative to cabling switches, space available 9 and so, no, the decision, examination was that manual 10 valves would suffice, then there was no decision to 33 enhance it by making it motor-operated. e 12 MR. SULLIVAN: Can you 13 elaborate, Ed, on the criteria for the manual valve? 14 I mean, y u said you made a determination that the . 15 manual valve would suffice. I assume that the ; Consumers people were involved. What were some of the 16 g -- what did you consider? MR. HUGHES: Well, essential-18 g ly Consumer, B & W and Bechtel people were involved in a review of this entire system and based on the loca-tion of the valves and their accessibility and the ! 21 ' time duration that was required for the system, and the availability and the purchase of valves, it was 24 HURON REPORTING SERVICE 7615328 i
t i I decided that it was sufficient to provide manual valves 2 and that an operator had sufficient information, 3 direction to go open the valves or so align the valves, 4 that there was no need for electric operation. Now, that is principally a time con-5 sideration and a location and availability of the 6 valves consideration, but that was extensively reviewed 7 and is documented in various meeting notes over the 8 9 course of, I guess, the past year. MR. GARRICK: Well, the 10 only question I was getting to is whether or not the 33
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intent here was really a mitigating system and if in-j deed that was the intent, then the time constants 13 could become important. g MR. HUGHES: I guess I need 5 a further definition of the mitigating system because
, it is a reactivity control system. It is designed to mitigate or to insure that you are in fact one percent shutdown for the conditions postulated. My interpreta-l 19 tion of mitigating, yes, it mitigates against a con-i dition that you would be less than one percent shut-down, but as far as a rapid response similar to the 22 emergency core cooling systems, no, it's not in that I
l 24 l I i HURON REPORTING SERVICE 761 5328-
i ( 1 category. , 2 Fm. GARRICK: Okay. So, well ,
-(
3 what I was thinking as far as short term was maybe less '{ 4 than an hour or half an hour and a system that would e l 5 enable you to perform boron injection or inventory , l 6 makeup and I guess what you're saying is that it was , 7 not intended to do that in the short term? g e g MR. HUGHES: No, it's not in 9 the short term. 10 MR. GARRICK: And the short i I term might be an hour or less? 2 11 MR. HUGHES: Well, our 12 13 design basis for the plant for the short term for < l y, emergency action is ten minutes and that's the basic ( 15 criteria. j L MR. GARRICK: Well, that's [ j 16 t i what's bothering me. There seems to be a substantial j 17 difference between that kind of short term and what you j gg jg said earlier about a coupi2 hours. l MR. HUGHES: Well, the two t 20 , I hours is a figure unique to the analysis of this g system. ! 22 ; MR. GARRICK: My closing ! 23 : i' 24 , i HURON REPORTING SERVICE 7615328
I 1 comment on this is that I'm having a little trouble . 2 seeing the real utility of this system. r 3 MR. HUGHES: Jim Agar, see if 4 y u can shed a little more light for Mr. Garrick on l this. l 5 l MR. AGAR: Well, for the - 6 record, I would like to add a document titled -- a - 7 8 number that has been transmitted to Consumer and to l t Bechtel that discusses in some detail the analysis and 9 Calculations. The title is Xenon Dynamics and Shut-down Margin. The document mmoet is 86-1123880-00. ; 11 , This document will shed quite a bit of light on the 4 12 e time aspect of utilization of the emergency boration i system. ; MR. SULLIVAN: I think the 15 primary -- just a comment on the utility, John, is the 16 primary concern really came out of -- there had been a lot of concentration before TMI about cettinc to a ' ' 18 certain condition and in our opinion after TMI and 19 some of the problems they had where they were afraid 20 for awhile of losing letdown, for instance, and other 21 limiting conditions. When you really look at the 22 limiting assumptions, you can talk about getting to a
- 23 24 i
HURON REPORTING SERVICE 7615328
. . - - _ _ - . . _ , - ~ . . _ . . _
6 h f 1 safe condition but if for some reason you don't want to 2 go somewhere from that -- in other words, you want to 3 stay at hot standby or even, in the long term, a 4 transition to cold shutdown -- the plant designs were 5 not always such that under the limiting assumptions, . 6 most reactive rod struck out, loss of letdown -- under [ 7 most limiting conditions, one rod stuck out, loss of .j 8 letdown, seismic events and so forth. You couldn't , 9 demonstrate that you could maintain those types of j [ 10 conditions wherever it was you wanted to be for an , P 11 extended period of time and so the emergency boration i system rationale was not a quick response system like ! 12 [ [ in a BWR, for instance, but the idea was can we main- ! 13 a g tain a safe condition for an extended period of time l l and that's why the time limits are on the order of j 15 urs rather than what you normally see. l 16 MR. HUGHES: John, again, 1 37 think, getting more to the thrust of your question, 8
'** Y "" "*#" " "** ' * #* " Y* Y "# "* '
19 f i high boron concentration system whereas other avail-20 ; t able sources of borated water were of a lower con-21 t
- i centration, and there's only a certain amount of space 22 available in the reactor coolant system, so we needed 23 ;
i 24 90- l l i HURON REPORTING SERVICE 7615328 , I 4
, , , - - - - - - a . - - . . - - . , - ---e e
h l I 1 a system that could pack in more boron with less l 2 _ volume than we otherwise had available. ! 3 MR. SULLIVAN: The low boron - 4 system ret 11y, as I remember early in the design, were i 5 selected based on the desire for normal operating
- I conditions to avoid large runs of pipe with heat tracing 6
7 and so forth and the attendant problems of reliability, . 8 maintainability and so forth. So it's effectively a L 1 l
, 9 compromise between the normal operating and the 10 2mergency conditions.
11 MR. TAYLOR: Let me see if I understand what you've just said, Terry. The emergency 12 l 13 boron system was to deal with the situation where, by 34 the time you got back to equilibrium xenon and started j to decay below that point, which is fifteen, eighteen 15 hours, I don't know -- it's way out there in time -- 16 37 and you made the assumption that you still had nc let-I 18 down capability and were not able to do anything aboutj the stuck rod, at that time frame, way out in several l 19 hours, that's when this system would be required to 20 start adding or it would have had to add negative 21 reactivity by that time, is that correct? 22 MR. SULLIVAN: That's correce , 23 4 24 HURON REPORTING SERVICE 7615328 g- -r-- m p r-9 yy 9 y-ay-g7.- 9+,imm.w - -p,.- -
, w cw& .wc r
1 as I understand it, and as the B & W gentleman said, 2 after xenon decays, you start slowly'to eat into your 3 margin and if you don't have maneuvering capability at 4 that point, say two hours and beyond, then this system gives you the safety grade capability to maintain a 5 safe condition. 6 7 MR. TAYLOR: When you say eat g into your margin, you mean reduce the one percent sub-
# " **#9 "
9 MR. SULLIVAN: Yes, under the most limiting conditions. MR. TAYLOR: I had a -- I'm sorry, John. MR. COOK: John are you getting.your questions answered? MR. TAYLOR: Do you have another one? 17 MR. GARRICK: Well, I had a
! 18 similar kind of anxiety on the HPI auxiliary spray and 19 as I recall, it must be aligned through a local manual 20 valve operation before it's available, available for 21 pressure reduction and, of course, during this period, 22 the PORV can cycle several times and could even fail 23 24 l
HURON REPORTING SERVICE 761 5328
l l to open and could stick open on any of the cycles. So 2 I was looking at the auxiliary spray system as a pres-3 sure reduction mechanism in, again, in the interest of 4 trying to implement the cold shutdown under the con-5 ditions that are specified, the thirty-six hour period, 6 et cetera, and again, it's the same kind of problem.
'i With the manual alignment and the possible time that's -
8 involved, maybe we're not taking advantage of this 9 system as much as we certainly could as a reduction, 10 pressure reduction device. 11 On the other hand, I am assured by i 12 operations people that this particular system, from an 13 operations standpoint, is very valuable and very 14 functional, but again, as a risk analyst, I'm looking 15 at it from the standpoint of what it provides to en-hance safety where for the moment we're talking about 16 j7 cold shutdown as an enhancement of safety. MR. GIBSON: John, I would 18 like to challenge your question in one area. There is 19 n t a tradeoff, as I understand it, between the 20 i auxiliary spray and PORV operation in that the 21 auxiliary spray is a cooldown and if you didn't have 22 23 it, you would not be challenging the PORV. You just 24 HURON REPORTING SERVICE 761 5328
1 wouldn't be cooling the pressurizer. The only 2 mechanism to challenge the PORV under those conditions 3 would be more a function of imbalance and heat removal 4 causing pressurizer insurges, I believe. 5 MR. GARRICK: So it's not so 6 deep, is what you're saying, as far as impacting the 7
-- or it's something you'd like to have available in 8
advance of cycling the PORV? , MR. GIBSON: I'm going to 9 back off and yield to Bechtel and the designers. 10
);
MR. BAUMAN: I think we need to have somebody summarize, like you did for the 2 emergen y ra n sys em, what the purpose is for 13 that auxiliary spray, why it's there and what the timing is. MR. HUGHES: Mike Pratt, 16 would you please give them a brief summary? MR. PRATT: Should the 18 operator determine that it is desirable to go to a j 19 l cold shutdown condition, the auxiliary spray system would provide the capability to do that, but the fact I that alignment of the system requires local, manual 22 actions is not a detriment to the overall safe con-23 dition of the plant. There's adequate time to 24 HURON REPORTING SERVICE 761 5328
-1 provide that manual alignment prior to the starting 2 of the depressurization and the cooldown sequence. '3 MR. BAUMAN: In other words,
- 4 the thirty-six hour time we have to achieve cold shut-5 down, you can maintain hot suutdown without the spray, 6 right?
7 MR. PRATT: That's correct. . .
-8 MR. BAUMAN: So the only g reason you need this auxiliary spray is when you opt 10 to go to cold shutdown and you have adequate time in the 11 criteria to allow for an operator action?
2 MR. PRATT: Right. 13 MR. GARRICK: I guess my g real question, then, would the availability of the spray within a short time period following a transient, i 15 say less than a half an hour, be desirable from the 6 g standpoint of limiting pressurizer PORV demand cycles.
. . A , m ust 18 g
comment briefly. We have not yet covered a section that B & W will present on recovery of plant from accident, transient scenarios, so I think some of your questions related to that may be answered when we get i to that part of the presentation. ;- l 24 4 HURON REPORTING SERVICE 7615328 i I
1 MR. HOOD: Mike, can I ask, 2 would that presentation get into the use of the 3 emergency boration system after certain transients? 4 MR. SCHOMAKER: No. 5 MR. HOOD: Basically my 6 question is I'm wondering if Mr. Garrick's questions 7 about the manual actuation of that system will come 8 into play again after the transient. 9 MR. PRATT: For the emergency 10 boration system or the auxiliary spray? 11 MR. HOOD: I'm referring now 12 to the emergency boration system. l 13 MR. PRATT: Okay. 14 MR. HUGHES: Darl, I can 15 answer that. No, we aren't going into that. We can i 16 expl re any questions that the review board wants to 37 go into but the actual presentation won't go into that. 18 MR. SULLIVAN: Well, again -- 19 MR. HUGHES: Transients and 20 accidents are really getting to a stable and safe plant ndition and the later decision to go to cold shut-21 down is, in fact, viewed as a later decision and not 22 ne f the inmediate actions. Therefore, the emergency , 23-24 : I I l HURON REPORTING SERVICE l 7ei.sa2e
1 boration system with the rods stuck out or the auxiliary spray, which is reactor coolant system controlled de-2 pressuri stion, are really later events, not immediate , 3 responses. 4 MR. SULLIVAN: Except that John's line of questioning will be answered in the sense that you have to address the immediate response of the plant to get to a stable condition and if in the presentation, whenever it takes place, you show g that you do that without needing the spray or in the i emergency boration system, then at least indirectly his questions are addressed, right? 12 MR. HUGHES : This is correct. 13 By process of eltnination, it has not been determined 14 to be needed; therefore, it is not needed in the short 15 term. 16 MR. BUDZIK: I'd like to 17 make a suggestion here. I know Rich has the slides 18 that he needs in that and we've talked around and 19 around the emergency boration system and I don't see 20 any sense to it because I think we have all the informa-21 tion that you need to understand where the criteria 22 and what the basis of the two hours were and the si=ing 23 ; l 24 HURON REPORTING SERVICE 7615328
I P 1 of the system and so forth. It is all based on xenon 2 curves for worse case conditions and I think Rich could 3 run through that in five minutes and give people an 4 understanding of how we got to that point and summarize 5 the report that B & W has given Consumers and Bechtel 6 f r their review and concurrence. l 7 Rich, why don't you go ahead. MR. HUGHES: If that's of 8 9 interest to the board.
. OOK: Excuse me. Let 10 me ask the board if it is their sense that they would 33 like to hear additional information on the' design basis g
f r the emergency boration system? I think we had 3 identified that it had been done by the work groups d I was going to have you certify to us as part of 5 the follow-up. My question is, do we want to spend more time now on the detailed backcround of the - 17 . emergency boration system? i MR. TAYLOR: Well, is that , document that Agar referred to going to be made i 20 ; available to all the board members? 21 MR. BUDZIK: It can be. It's 22 i right here. Certainly is going to be at least by
.23 . ,
I
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HURON REPORTING SERVICE r 7615328 l
l 1 reference and then if you wanted to, we could make it -- 2 it can be made available. We have it right here in 3 ur hands. I can run Xeroxes in a half hour. 4 MR. COOK: I think the sense f the board that I have is that we'll take that by 5 g reference and then if the individual members want to pursue it further by reviewing the actual referent:e 7 umen s, we'll do that, 8 g MR. BUDZIK: Fine. O MR. COOK: Or if we have additional time later on and it makes sense, we may come back to it. 12 MR. SLADE: I have a couple idler questions. MR. HUGHES: Could we go off the record for a minute in that we need to change the paper for purposes of the transcript. (Short break.) 18 MR. COOK: We're back in 19 session. 20 MR. HUGHES: Jim, if I might 21 take a minute, I believe that Mr. Lange has one comment 22 relative to the c=orgency boration system criteria 23 24 HURON REPORTING SERVICE 7615320 e
l 1 that may be useful for the record and further explain 7 l - 2,; actkn ta sone people as far as criteria. ' 3 MR. LANGE: Just a couple ! 4 words about the timing aspect. The most probable con- l 1 5 dition is operation from one hundred percent power. i 6' In that case, the actuation requirement is going to be 7' about twenty-four hours. It is a very long term - l 8 operation. The two-hour criteria is based on a . t 9 double reactor trip where the second reactor trip is 10 the one where the rod sticks out. There are some 11 calculations made regarding the reactivity insertion 12 rates at that type of situation where you theoretically 13 got back up to hot full power temperature but really i 14l didn't disturb the decay profile of the xenon. That l 15' was where the two hours came from. , 16 So, the two hours is under worse case 17 situations as opposed to most probable. 18 MR. HUGHES: Okay. With that, , 19 the board's questions? 20 MR. COOK: I believe we're 21 at the point at where it's profitable to go ahead. I ; 22 think where we came in that entire extended discussion , 23 was; one, questions on the design basis and interface 24 -100-l HURCN REPORTING SERVICE 7615328
1 in the design process, the documentation requirement 2 and ability to analyze multiple operating conditions 3 with regard to the operating and emergency procedures 4 and, three, the observation by Mr. Garrick that his 5, sense as a risk analyst in hearing some of the system 6 descriptions and design bases is there might l e 7 cpportunities for additional enhancement of the safety ' 8 of the plant based on his experience in risk analysis, 9 which he is doing right now for the Midland plant. I 10, think, therefore, we should, not this Design Review l1 Board but rather the ongoing risk analysis of the 12 Midland plant, should take advantage of the potential 13 he sees and evaluate as part of the ongoing program 14 and I'd refer that really back to Dr. Sullivan and 15 Mr. Garrick to take that as an action item in their 16 ng ing work. 37 I don't think the design board was 18 constituted to try to, you know, attack that question gg and clearly not to try to look at it, and much less 20 resolve, potential design changes, you know, ongoing 21 unless we find a deficiency,, so I think we would simply i I 22 refer that potential which I think we ought to explore t the ongoing PRA work. 23 24
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1 MR, SULLIVAN: Okay. I'm 2 sorry. I didn't realize we were missing Darl Hood 3 when we went back on the record. Does anybody -- 4 MR. MAZETIS: He went to 5 make a phone call. l 6- MR. HUGUES: Would you prefer 7 to wait or would you prefer to proceed? - 8 HR. COOK: Do you gentlemen ' 9 'have any sense of whether we should -- 10 R. MAZETIS: Let's go on. j) MR. PRATT: Ed, I've just got one point that I would like to make. Mr. Taylor had asked a question previously about the design basis 13 information for auxiliary spray and we had an open action item to provide to the Design Review Board the details of that design criteria. We're assembling some 6 information now and, time permitting today, we'd like to provide that within the presentation rather than at a later date, if that's acceptable. MR. COOK: Well, I think the 20 procedure we were going to follow was that the board is going to reserve time to caucus as we get towards the 22 23 -102-24 HURON REPORTING SERVICE 761-5328
1 end of the overall meeting and at that point I would 2 ask us all to reconsider exactly what we thought we 3 needed to pursue and then we'll come back and specify 4 it and discuss it with the, you know, with the present-5 ing organization to make sure we all understand where 6 we go from here. , 7 MR. HUGUES: All right. If . 8 there are no more questions on information to date - 9 MR. BAUMAN: I've got ques-ti na on some other aspects. Can we do those at this 10, jg time? MR. COOK: Yes. The 'loor is 2 still .,, pen for design board questions on the material 13 g that's just been presented to us.
" *
- U" #" "" 9 "
15 a new topic, can we Clarify the action item associated with the operating specs?
* ' Y'
- 18 19 MR. SLADE: All right.
MR. BAUMAN: This may not be the appropriate time, and someone tell me if we are going to address this later on, but I think we need to 24 -103- l
! I i
l 1 l HURON REPORTING SERVICE 7615320
i 1 get into the natural circulation cooldown report steam 2 generator and the fact that there is still an analysis 3 to be completed on that. Is this the appropriate time 4 or will that come out of a later part of the presenta-5 tion? ! 6 MR. HUGHES: I believe that ! I the statement really is that natural circulation cool-7 ( 8 down and one steam generator has not yet been fully l 9 analyzed and I really can't say anything further about [
. 10 it at this time. !
j) MR. BAUMAN: Well, I would like to know when the analysis is going tc be complete 2 g and what the schedule is. Do you have any other g references where you've done similar analyses on other i plants and so forth? Do you care to discuss it at all? 15 What I would like to have is feedback on discussion. 6 MR. HUGHES: Jim Agar, would 7 I you care to address that? 8 MR. AGAR: Ron, the best I t can do right now in responding to that question is to say that the natural code is being revised at this time to include the ability to be able to analyze the cooldown, natural circulation condition with the use ; 24 HURON REPORTING SERVICE 761 5328
1 of one steam generator. The schedule for completien 2 of this model is being developed and I would guess that 3 within the next two or three weeks that we should have , 4 a schedule when we can complete such calculations. M. A : n at analys s, 5 are you also considering two-phase recirculation, ! 6 7 circulation? , MR. AGAR: I would assume e 8 i g that they are, yes. MR. GARRICK: Okay. It seems O that I remember somewhere in some of the material that
)
such a study was going on and I guess I'm asking.
* ^^ * *11' "*'#" "D i 13 contemplating --
MR. COOK: Through the board or some other external material? 16 MR. GARRICK: Well, I'm not 17 sure. 18 MR. AGAR: We're not con-19 templating really a two-phase mixture. To my knowledge! , 20 there's no special study being done, at least to my knowledge, within B & W for a two-phase recirculation. 22 The code, like I say, was used for the -- two steam
- 23
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- 761 5320 l
l 4
1 generator cooldown is being revised to be able to 2 just look at one steam generator. 3 MR. TAYLOR: I could clarify that a little bit, John. There is, not in connection 4 with this cold shutdown issue but in connection with the , 5
! small break._ issue, two-phase circulation on the pri.-
6 mary side and the effect of non-condensables and so on. 7 L g , That is used, being given a lot of attention in connec- , lj , g, tion with a NUREG. document 0565, but two-phase cir-I culation is, to my understanding, this particular , 101 issue is not being addressed. MR. COOK: In response to the (
,2 comment, the material handed to the board on top of page 17, I think, is clearly an open item and we'll ,
take that as such from B & W. 15 MR. AGAR: That's true, it 16 l. is. 17 MR. COOK: Mr. Jensen? 18 , MR. JENSEN: I was wonderinc ~ 19 ' if the consideration of reverse flow in the non-20
, operating reactor coolant loop will be concerned in 211 the natural code? Will that possibility be allowed for:?
22 MR. AGAR: Iwouldimaginesol, l 23, I l yes. i 24!
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l
1 MR. COOK: Can we specify 2 with certainty or does that have to be followed up on? 3 MR. AGAR: Until the details 4 of the code modifications are known, you know, it would 5 be very difficult to answer that question. g MR. COOK: So we'll consider 7 the response to be uncertain, to be confirmed? - 8 MR. AGAR: The issue is still , 9 open until we can confirm that, right. 10 MR. BAUMAN: Okay, so that 11 will be an action item, then, to complete that analysis 12 and continue to evaluate it.
. 13 MR. TAYLOR: I have a 14 specific question which I think may relate to the 15 question that Mr. Jensen just made or just asked and that is in connection with single loop cooldown. Is g it correct that the emergency boration system connects f
g into one loop? It is not -- this schematic is correct n a system coming in kom -- is only connected 19 into one reactor Coolant loop? If you pttt the high concentration boron in with one makeup pump, is that going to be separated so that it only goes into the high pressure 24 -107-HURON REPORTING SERVICE 7615320
1 injection nozzle; the background for the question being, 2 could you end up with all of the concentrated boron in 3 a dead loop and not in the reactor? 4 MR. PRATT: The specific 5 injection path needed by way of makeup or the HPI line f 6, has not yet been determined. 7 MR. TAYLOR: It would then 8 seem that that's an issue that ought to be pursued in g connection with the overall emergency boration system 10 design evaluation, including the provision for sampling 33 during operation to not only make sure that the con-12 centrated boron is going into the core but that the 13 Sampling pisions fbr measuring that are really repre-g sentative of what's in the core. 15 f4R. PRATT: Yes. There may g be some additional clarification that B & W Would like g to make on that. This subject came up early on in the 18 3g getting the horic acid where you want it. MR. TAYIDR: The only thought is here an eighteen hundred gallon tank is not very big compared to the loop volume and so if that happened , to be -- if you're putting the boron only into one
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I loop and that loop happened to be the idle loop, would 2 want to have assurance that it was being distributed 3 into the core. 4 MR. SLADE: There would still be some flow in the idle loop. It's just a question 5 6 of what the time concept would be for getting to the , l 7 core. MR. GIBSON: Mr. Taylor's 8 , g question really is appropriate. Whether you're using the EBS or BWST, you are under natural circulation or 10
;; non-forced load conditions. Should be concerned that the way you inject the increased boron, whatever the 2
source, that it be appropriate. 13 MR. TAYLOR: Could somebody 14 describe the sampling provisions when you would be in ; 15 e the mode of using the emergency boron system? It's 6 . Y my understanding from reading the material that the g sampling li is e ted to the letdown line but one l 8 of the things that requires the use of the emergency g boron system is the inability to .ise the letdown line so what reviews have been made or what assurances can be provided that the sampling you get out of that line, which is not in use, is really representative? ;
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HURON REPORTING SERVICE 761-5328
I
!! i 1 MR. BAUMAN: I would like to ,
2 just add to that question, and Lou just mentioned it, 3 too, that the boron mixing in the reactor coolant - 4 system during natural circulation cooldown, I'd lixe 5 to hear a discussion from the appropriate -- 6 MR. COOK: Can we give the 7 design team a chance to answer these, you know, one at I 8 a time as they come up? 9 MR. BAUMAN: Well, they're r It's more than just, one, the loop. 10 related. It's jj whether you've got forced circu*ation or unforced circulation, the whole big question about boron mixing. 12 l 13 MR. EUGHES: I believe that + 14 we will cover the boron mixing and go on into those 15 questions in better form af ter we've had the presenta-t g tion of Chapter VI, which is the comparison to l g ; applicable regulatory guidos, and I believe that's i in fact addressed in the material there briefly. ! MR. COOK: Take. that as a 19l j comeback item, fine. We'll defer to when you want to 20l1 address it. 21
! MR. MAZETIS: Has the i 22l analytical medel referred to earlier been submitted to 24 -110-HURON REPORTING SERVICE 7615328
1 the NRC staff?- I believe B & W referred to it. MR. HUGHES: Gerry, this is 2 3 the question of the natural code and the modifications tnac Agar referred to? 4 MR. MAZETIS: No, the dis-5 ussion referred to an analysis of one steam generator l 6 7 under natural circulation. MR. HUGHES: Okay. That was 8 9 referred to as the natural code. Mr. Agar, would you care to answer that? MR. AGAR: To my knowledge, 11 Gerry, that code is not completely certified yet at this stage. I don't know. Perhaps Mr. Taylor could help me out here in the licensing area, but I don't believe that there has been discussions with the staff 15 on the natural code yet, is that right, John? 16 MR. TAYLOR: As far as I 17 know, they are not. 18 MR. AGAR: It is not a 19 certified code yet. They are still working on the 20 certification of the code. 21 MR. MAZETIS: Are there plans 22 to submit it to NRC? 23
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1 MR. TAYLOR: Not that I know 2 of, no. In terms of topical reports or that sort of 3 thing, I don't think so. In terms of topical reports, ;. 4 I believe not. I believe there is not a plan for that 5 code to be described in the topical report. 6 MR. GIBSON: As long as we're 7 talking about the natural circulation considerations,
- I had a question. It's probably twofold. One, it has 8
9 to do with the DHR cut-in. We've alluded to an elevation of the DHR cut-in temperature in the primary 10 11 system and, first, I would like to know what kind of cycle limitations there are. I assume that they change j2
- 13 as you elevate a temperature on a system that was de-14 signed for a lower one; and secondly, if you're into natural circulation, it seems to me that one of the 15 16 prime reasons that you might be would be a loss of i ffsite power and, therefore, you would need that 17 elevated temperature and I would think that maybe the 8 -
jg hot leg temperature would start the diversion with Cold leg. You'd be in a problem. MR. HUGHES: Tom Ballweg? MR. BALLWEG: Regarding the 22 number of cycles, I don't know that number. Do you? 24
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j MR. PRATT: Well, we have assumed, obviously, not a normal situation. It's de-2 fined as an emergency condition and I believe we're 3< , designing to one cycle per year, forty cycles during the plant life. MR. BALLWEG: The second part of the question, yes, the hot leg and cold leg tempera-7 ture are in fact much different under natural circula-8 tion conditions and we are talking about a hot lcg temperature of 325 for cut-in. I do not remember exactly what the cold leg temperature would be under those conditions. 12 Am I getting to your question, Lou, 13 , or not on that part? 14 MR. GIBSON: Well, I think it 15 is the hot leg temperature or the highest point that 16 you have to -- 17 MR. BALLWEG: Yes, it is the 18! hot leg temperature. 19
- iR. GIBSON: I think we'll 20 get into the rest of it in aux. feedwater, I imagine.
21 I'm concerned about whether we have any steam lef t to 22 drive the turbine drive. 23
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i 1 MR. TAYLOR: Do I understand 2 that the only basis for changing from 280 to 325 was in 3 order to meet the thirty-six hour requirement? 'i 4 MR. BALLWEG: Basically the 5 requirement is to enable -- falls out in order to get 6 enough steam venting capacity off the main steam lines, 7 off the steam generators and cool the reactor coolant
- 8 system down in a reasonable amount of time. The thirty-g six hour number comes from Reg. Guide 1.139.
10 MR. MAZETIS: Do you have a j) calculation of the amount of time it would take to get to the 2807 13 MR. BALLWEG: To 2807 MR. HUGHES: Gerry, you have )4 5 280, under what conditions are you asking, under norma.' cooldown? 16 MR. MAZETIS: Yes. 7
, MR. BALLWEG: Under a norr.al g cooldown, you're basically limited by the RCS spec, 100* per hour cooldown rate for most of the cooldown and then at the very tail end where you were dumping to the condenser, you're limited by the valve capacity.
It takes less than six hours to cool down to 280 under 23 a normal plant cooldown. 24
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1 MR. MAZETIS: Okay. Using 2 the same assumptions utilized to derive the thirty-six 3 hours, how long would it take? 4 MR. BALLWEG: I don't under-5 stand the question. Could you expand a little? e MR. HUGHES: Are you relating 7 to using only Class lE equipment? g MR. MAZETIS: Yes, right. 9 MR. HUGHES: And a loss of 10 offsite power? jj MR. MAZETIS: Right, if they 12 were the assumptions. As I understood what you just 13 said, you said it would take thirty-six hours or'you
.g could do it within thirty-six hours, get to the 325' emergen y ut-in point. So my question was, using 15 the same assumptions, what would it take to get to the 6
200* cut-in point; forty-eight hours, seventy-two, 7 seventy-two hours? Do you have a feel for that? g MR. BALLWEG: I don't know that that's been analyzed out that far. I don't really know. MR. SULLIVAN: Without decay I
- 22 i
heat removal? . 23 l
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j
p-1 MR. MAZETIS: To get to the 2 cut-in point. 3 MR. HUGHES: Yes. The ques-4 tion is without offsite power and using the Class lE 5 components, how long would it take you to get to the 6 280? 7 MR. SLADE: In my review of 8 this previously, I recall looking at the saturation g pressure associated with 280 . I think the concern is that you don't have enough pressure to operate the 10 auxiliary feedwater tubine-driven pump and if your 11 2 single failure is the motor-driven pump, then'you don't have -- you need to cut in at a higher temperature so 13 that you still have feedwater at the point where you're 34 Cutting in auxiliary feedWater. MR. GIBSON: Can I ask for a 16 clarification? The thirty-six hours is the cold shutdown, am I correct, for the right guy? Tha t' s 200', not 280 or 325? g MR. GUNNING: May I clarify? 20 The thirty-six hour time period is the time to have your DHR system operational. MR. GIBSON: Okay. So it's 23 l
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I 1 not 200? Thank you. 2 MR. PRATT: And one other 3 point, correct me if I am wrong, some of the licensing 4 people, but I do not believe that the licensing position 5 on the Midland plant is that-attaining a 325 or 280* 6 decay heat cut-in temperature as a design basis for the 1 7 plant. It's a design objective in the plan. 8 MR. TAYLOR: You mean in 9 thirty-six hours? 101 MR. PRATT: Within thirty-six 11 hours. 12 MR. HUGHES: That is correct. 13 This is a new regulatory guide relative to the con-14 struction permit in the vintage of the Midland plant, 15 so this is an enhancement to demonstrate capability 16 and we will go into that when we get into Section VI, 17l I believe it is, on the comparison of the present U*81 9"* 18 i 19 MR. TAYLOR: I'd like to ask for a clarification as a follow-up action item 20 s to just exactly what the basis was for shifting i 21 fr m 280 to 325 Lecause it seems, if it was simply 22 mee .e r y-six hour requirement, which is an 23 24 -117-HURCN REPORTING SERVICE 7615328
i i 1 arbitrary requirement, it might be worthwhile to re-2 consider having to subject the system to that change. 3 Correct me if I am wrong. Is the thirty-six hours an 4 arbitrary requirement? 5 MR. MAZETIS: I agree, it's 6 an arbitrary. It's a number that in the past five, 7 six years has been utilized to focus on the term, 8 reasonable period of time. We've accepted values 9 greater than thirty-six hours; forty, forty-eight hours , particularly for near term p.L.'s. While I guess I 10 11 agree with Jim, the thrust of your comment, I would 2 presume that all they were trying to demonstrate was 13 the capability if needed to get to the RER system with- - g in that period of time. The actual need for doing that w uld be determined under the conditions of the re-15 a ra .e me s fast shutdown was required and 16 presumably for a normal shutdown, they would, you know, 37 they wouldn' t take advantage. 8
* " * " ** " "# Y 19 one thing. I don' t believe we stated that the thirty-six hours was the only reason we went to the 325.
Tom, would you go back to what you said about the steam venting and pressure? 24 -118-l HURON REPORTING SERVICE 761 5328
l 1 MR. BALLWEG: Basically, well, 2 the 325 does fall out not specifically from the thirty-3 six hours. It more falls out from the reasonable time j 4 assumption where you basically come at -- and I'm reflecting strictly on memory, something that I saw I 5 6 quite a long time ago -- that it took, to get to 280, 7 it took something in the range of three days, two to 8 three days to get there using one valve and with the 9 idea of meeting a single failure requirement to assure l 10 the -- we had a steam vent path for each steam generator 33 and providing a reasonable capacity and during a 12 reasonable time, the 325 kind of fell out in the wash 13 as being the number which was achievable from a DHR 14 system design and still compatible with a reasonable 15 down the. l It Was a Compromise number Considering 17 both the DHR system performance, equipment and limita-tions and capabilities, and the implementation of the 18 , g reasonable time concept.
- I Y " *'"
20 i is whether or not there are any significant adverse j 21 , effects on the decay heat system as a result of shift-ing 230 to 325.
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1 MR. BALLNEG: I think the 2 short answer to that is-the stresses, thermal stresses 3 are going to be higher. They have been analyzed and 4 determined to be acceptable as an emergency level stress. 5
-l MR. TAYLOR: Are those t;ade-6 offs worth whatever the basis for sh t icing really was?
7 MR. SLADE: Let me interject 8 g here, because I did have in my notes the numbers of the saturation pressures for those temperatures. At 10 280* Fahrenheit, the saturation pressure is fifty 33 pounds absolute. Okay. The required pressure for peration of the auxiliary feedwater turbine-driven 13 pump, I believe, is thirty pounds gauge, is that -- or, no, forty-five pounds gauge, which would be sixty pounds absolute and, therefore, you could not assure the pump volume necessary at the 280'. You had to go to some elevated temperature. Now, whether 325 is an appropriate basis or not, 325 happens to be ninety-seven pounds absolute and clearly is above the required pressure to el operate those pumps So someplace between 280 and 325 22 is necessary in order to assure that you can put 23
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24 HURON REPORTING SERVICE 7615328
1 ' auxiliary feedwater to the generators if you don' t t 2 have a motor-driven pump. I 3 MR. SULLIVAN: It is stated ' 1 l 4 as an emergency operating condition. It's not some-5 thing the operator would routinely do, Jim, so it's 6 not, you know, as I read it, you know, it's the option 7 of the operator when he gets there to make the judgment . 8 as to whether he needs to cooldown that quickly. 9 MR. TAYLOR: These numbers 10 have a habit of creeping into the operating procedures 11 and it would certainly be worthwhile to have that be 12 an option to the operator, let's say, to go to 280 if 13 you can. You don't have to actuate this sytem in these conditions unless you're without your motor-driven 14 15 E""P' MR. BAUMAN: This would have 16 to be the case of giving the operator an option because 37 they're, therefore, limited to 40 cycles. That's going 18
;g to be controlled and that will have to be identified somewhere as operating procedure.
MR. GIBSON: I think what Jerry alluded to and what Jim may be coming up on is 27 that when you get down to the point where you have to 24 -121-ll HURON REPORTING SERVICE 7615320
- I
1 utilise that 325, if you don't have conditions in your 2 primary system such as some kind of a major leak or
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3 something elce, in other words your conditions are 4 acceptable from a safety standpoint, then it's prudent 5 n t to exercise the emergency switchover. I agree with y u. I an see where the operators get down there and 6 7 they say, all right, the clock is cranking away. I'm - at thirty-two hours. What's my course of action. The 8 g smart course of action isn't necessarily to meet the thirty-six, is what you're saying. MR. SLADE: Lou, this gets 12 back again to the need for operating specification re-13 quirements as long as were identified the numr er of cycles 14 that are available that are in the operating specs. Thosle are control basis for our operating procedures and emergency procedures. We will factor that into the 16 operating procedures as limitations for the operator. I would propose that -- or I would not expect that we 18 19 would even give the operator the option of cutting in-to the decay heat removal system before 280' unless ! 20 we're in an emergency operating condition. The only 21 place where that limit would show up is in the emer-22 gency operating procedures, not in the normal operating 23l 24 -122-l t > HURCN REPORTING SERVICE 761 5328
1 procedures, and then only when the steam-driven auxil-2 iary feedwater is not available -- or, excuse me, when 3 the motor-driven auxiliary feedwater pump is not , 4 available. , 5 MR. COOK: Just one practical follow-up question, Ed. In terms of the original 6 7 7 thrust of that question, we're looking at really ,. 8 verification of the system to be able to do what we 9 said it could do; in this case, be able to cut in at I 325'. The changes have actually been made in the plant 10 i ' 11 design, have they not? MR. HUGHES: That is correct 2 13 and they have been analyzed and reviewed with B & W's and Bechtel's equipment and found to be on acceptable g i limits. They are code equipment and they have speci-5 16 MR. . vK: Okay. I think the g thrust of the comments of the board are, you know, 8 , g appropriate in terms of not doing anything you don't have to do that might be additional wear and tear on ' 20 the plant. MR. TAYLOR: I have some ;
; 22 r additional questions on emergency boration system.
s 23 24
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1 As I understood the way the conversation went earlier, 2 there were some specs prepared for the emergency bora-tion system and these specs were turned over to Bechtel ; 3 4 and they designed the system and that loop is being closed or will be closed to see that the requirements 5 6 that were set have been implemented. 7 Now, the third part of that question , 8 is, for those parts of the system which were physically g unaffected, has there been a review for compatibility 10 with the new functional requirements; for example, all t gj the things that are now going to see six weight percent. 12 boron, have they been looked at to see whether or not 13 they are really compatible with that higher concentra-tion, like the makeup pumps or whatever? Was that a 14 clear question? 15 MR. HUGHES: I believe you 16 just asked, have we reviewed, where we've changed the 17 system, that the existing equipment we're utilizing 18 jg is compatible with the new requirements. I believe the answer to that question is an unqualified yes. 20 MR. PRATT: Yes. 21 MR. TAYLOR: Is that review 22 documented anywhere? 23
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1 MR. PRATT: Not that I'm 2 aware of. 1 3 MR. HUGHES: Rather I believe 4 what you'll find is in the equipment specifications, 5 the requirements on the system and where a new imposi-6 tion does not take you out of that boundary of the 7 requirements, no further documentation is provided. ., 8 Should you require additional qualification informa-9 tion from your vendor or from the materials that we 10 have supplied, then that would show up in the records. 11 There is no formalized review procedure of this h2 particular aspect except as it's in the design descrip-13 tions and the licensing documents. MR. BAUMAN: Jim, I know in j 14 1 15 your case we actually funded an effort where you went 16 back to your heat exchange suppliers and had them analyzed for this type of condition and that will 17 bviously be documented. 18 gg MR. TAYLOR: You'll have tc
-- I'm not involved with that detail.
20 MR. BAUMAN: I know in the g as f y ur equipment it is documented. 22 MR. TAYLOR: So to get at
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I what you just said, and perhaps to reflect what Ed just 2 said, somewhere or another there's a piece of corres-3 pot.dence that says the high pressure injection pump 4 has been evaluated for compatibility with six weight l 5 percent boric acid and it's okay? 6 MR. HUGHES: No, that's not 7 what I said. ; g MR. COOK: No, that's not
^
9 what I heard either, that he's revised these design documents to make sure that those at the higher con-10 , 33 centration, that it might say due to the EBS is now ' included in the design documents. ; 12 MR. HUGHES: Where affected. 13
?
MR. COOK: And you'd have to 14 go back and audit the design documents to verify that it was done right. 6 MR. HUGHES: It's a reverse g procedure. The desirjn documents that specify the 8 requirements for the system when a change is made are g reviewed and if the equipment specification and equip-ment supplied are compatible, no further change is necessary. There is not a piece of paper saying a l review was conducted for this purpose and found to be 24
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1 acceptable. Rather the documentation for the equipment 2 specifies its conditions and if you look at the new
-3 conditions, you find them within the envelope. .
4 MR. TAYLOR: Well, then, to ' 5 put that in different terms, someone would have gone l 6 back and said, six weight percent is within the , t 7 envelope of these portions of the system which are 8 already designed and so, therefore, we don't have to 9 look any further? MR. HUGHES: That's correct. 10 11 MR. COOK: Okay. One follow-up, if you found cases where it did not fall in the 2 envel pe, then the design document would have to be 13 upgraded to include the new more limiting condition 14 and you would do something to either, you know, verify 15 I i that you could meet the new condition or make a modific'a i 6 g tion? MR. HUGHES: That is correct. t g g You'd either be back to the vendor for certification as-to additional capability or you would be into replace-ment of equipment and/or components. MR. COOK: Jim, my sense of what I heard was that the only way you could really 23
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1 verify your question or to successfully answer it would r 2 be to audit the design documents. , 3 MR. VANHOFF: If I might . + 4 interject, I think at one time we were looking at sever 5 percent boric acid for the addition system a long time 6 ago. ; 7 MR. HUGHES: That's correct. . t g MR. PRATT: Yes, the history. 9 MR. VANHOFF: So I would ' assume that the documentation for the pumps would have [
, 10 ,
included six and a half percent. l 11 . MR. SULLIVAN: And as I 12 mentioned before, I think we went to the lower concen-13 tration to avoid the heat tracing problem we had had at , Palisades and the operator inconvenience of trying to 5 maintain large piping runs and tanks with elevated f 16 t boron concentrations. MR. COOK: But from quality assurance aspects of Mr. Taylor's question, tSe claim g is that the design documents specify the requirements of the equipment. We'll have to see and it's reallv, you know, an auditing review function that would either prove or disprove that.
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l l MR. TAYLOR: Okay. What 2 temperature does the six weight percent crystalize at? 3 MR. HUGHES: Mike Pratt? 4 MR. PRATT: Yes, that 5 crystalizes at approximately 83 Fahrenheit and I have 6 the basis for that provided in a - 'that number is 7 from a B & W specification. 8 MR. TAYLOR: The follow on 9 to that is has the periodic testing that will be done-10 on the emergency boron system been determined yet? MR. HUGHE!i: Jim, what do you 11 2 mean by periodic testing? MR. TAYLOR: Well, to make . 13 f sure that the lines are free periodically when you need 14 15 it and so on. MR. HUGHES: Are you talking 16 once the plant is in operation? 37 MR. TAYLOR: Right, correct. 18 i MR. HUGHES: I believe that jg that has not been determined yet. I'm speaking for 20 the operations department in part and I guess I really 21 have to go back to Mr. Slade, but as far as I know, 22 that has not been determined yet. Periodic maintenance 23
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24 HURON REPORTING SERVICE
.7615328
1 and tests on the emergency boration system has not yet 2 been established by the consumers Operating Department. 3 MR. SLADE: We don't have the 4 system designed yet. MR. GIBSON: I recognize we'r a 5 6 seemingly hung up on EBS, and I guess I'll add to it. 7 The design considerations when ycu need that EBS after two or twenty-four hours, you want it into the primary, 8 g am I correct? Do you shut off the recirc to make sure it gets there or do you put a lot of it back into the 10 m keup tank? 11 MR. PRATT: You secure the 2 reCirC panel. MR. GIBSON: Okay. MR. PRATT: The reference for 5 the 83* temperature is B & W standard guide, specifica-tion number 2016, boric acid for nuclear plant applica-tion, figure 1, which is a solubility curve of boric I acid. 19 MR. GIBSCU: I would ask you 20 how you secured the recire, but I know the answer and that will be, developed in the operating procedures 22 so -- 23 I
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1 MR. TAYLOR: Well, at the 2 I risk of sticking on emergency boration systems for 3 awhile longer, I realize what you said, Jerry,was true, ., 4 that the periodic testing has not been set because the 5 system has not been designed completely yet, but these
. are not unrelated. It-could be that there are some 6
recirculation lines required for periodic testing which , 7 w uld have to be included in the design, and so I would 8 9 just ask that the need for periodic testing be given . some consideration or suggest the need for periodic 10 testing be given some consideration before the design 79 is absolutely finalized. If there are some special 2 reCirC lines to make sure that the boron has not crystalized in some low temperature spots or something , 14 like that where you're going to run a test once a month e or whatever, that that be a factor in the design, the l' 16 final design review. MR. COOK: Let's ask the 18!i question a little bit dif ferently. Can we have the 19 design team tell us what the operating conditions or 20 characteristics, considerations that have been put 21 into the design? 22 MR. HUGHES: Mike, why don't 23
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1 you go into the considerations in the design of the 2 EBS as far as prevention of crystalization. 3 MR. PRATT: Okay. I don't , believe I have an overhead on that. There is one 4 5 approximately twenty-three hundred gallon EBS tank per unit. There is a single approximately 15 gpm 6 re;irculating pump to recirculate the contents of the 7 EBS tank during normal plant operation, mix it. The 8 g tank contents are heated by way of immersion heaters. They are non-lE immers' ion heaters which maintain the 10 contents of the tank at approximately 160*, well above 11 the crystalization temperature. 2 There are capabilities for addition 13 of concentrated boric acid and for addition of de-14 mineralized water and there are also capabilities for periodic sampling so the operator would, by tapping into the recirculation loop, draw off a sample, take that to a lab for analysis of boric acid concentration 18 or for whitever ac determined by the operating pro- , 19 cedures, but those capabilities do exist in the design.I. 20 I think that pretty much describes the design of the
. 21 emergency boration system as far as its normal standby 22 mode when it's not being injected.
23
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1 MR. TAYLOR: So it is normall:7 2 in circulation, then? 3 MR. PRATT: That's right and - 4 that's done to keep it mixed, uniform temperature, 5 uniform concentration. 6 MR. HUGHES: Mike, in the ; 7 course of our design evolution of the EBS, has this , 8 system been discussed with both B & W and Consumers 9 operating Department? MR. PRATT: Well, we issued a 10 11 sysnem summary-description for the emergency boration h2 system and that was provided to B & W for comment and 13 to Consumers Power for comment. We have received those comments, finalized the system summary description, 34 finalized the design. 15 MR. HUGHES: Did we have a 16 meeting with Consumers operating at the job site? g MR. PRATT: Not specifically g on emergency boration. g
* "
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- 20 the design changes, we have had meetings at the Midland, 21 l job site with both Bechtel construction as far as effects on schedule and with Consumers operating 24
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I 1 people so that they're aware of and can plan for future 2 changes, and I presume that we will probably do this 3 for the EBS and other changes, an ongoing program. 4 MR. COOK: Do we have further 1 5 questions on the presentation we've heard so far? John? 6 MR. GARRICK: I wanted to 7 c mment a little bit about some of the systems; in - 8 particular, in reference to the earthquake and since g we're talking about evaluating cold shutdown in terms f the ability to do it in the presence of the safe 10 g shutdown earthquake and the loss of offsite power, the question of the ability of the equipment to all run effectively under these conditions is kind of inportant. I wanted to hear a little bit of discussion on some of 14 tha specific key systems and I guess, in particular, will the borated water storage tank in the cervice water piping survive the safe shutdown earthquake? Also, the layout of the plant is such that the borated water storace tank is located in the
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19 l back of the plant buildings and the service water 20 structure is a considerable distance from the aux. 21 building and so the issue of the interconnected timing 22 becomes kind of important and maybe rather than ask a 23l 1
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1 question of will it survive, maybe somebody can talk a 2 little bit to what the earthquake levels are or that 3 these have been designed to in terms of something like 4 ; equivalent peak background acceleration. 5 MR. HUGHES: Well,_ essentially 6 the design basis of the Midland plant is a .12g 7! horizontal ground deceleration and the seismic category 8 one structures, equipment components have all been 9 analyzed to withstand the decelerations associated with 10, a .12g earthquake and the stress levels have been 11 acceptable under. the industry standards. MR. COOK: To follow John -- 2 a little bit more completion than that in terms of the 13 . 14 damping values and the actual specter that's developed and so forth, you have to get a full feel for it. You 15 have to go through all of that. 16 MR. GARRICK: Well, also, g 18 it's my understanding that the chemical addition jg system is not seismically qualified. MR. HUGHES: That is correct. 20 MR. GARRICK: And if you try to track down the water sources, then I guess the question is, even though it's not seismically qualified,
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1 -because it enters into the water supply question, do we 2 know what its relationship -- do we know what its 1 3 resistance is, for example? - MR. HUGHES: No, we don't do 4 5 a -- what I call a back calculation in terms of what it will withstand. The chemical addition system is net > 6 7 required for any safety response to an earthquake con- . 8 dition. 9 MR. GARRICK: I guess if the borated water storage tank line fails, for example, 10 11 that there's a good chance that the high pressure and the low pressure pumps will fail due to loss of suc-
}2 .
tion, is that right? 13 i MR. HUGHES: I believe that's 14 correct. 1 15
. A : n a regard, 16 have you considered some type of low suction pressure 37 protection, particularly for the HPI and the DHR pumpsi 8
MR. HUGHES: The design basis
)g for the Midland plant does not include the passive ,
O failure of a seismic Class 1 line as part of the plant 1 design basis. 22 MR. GARRICK: Okay. Well, 23
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1 one of the reasons for the question is I know the desiga 2 basis is not, but coming from the point of view of a 3 risk analyst, we have to address the question of what - 4 the ability of these structures are and so part of the 5 question here is really what is the threat to these , 6 key components and interconnecting piping with respect i 7 to achieving cold shutdown during an emergency con- ! 8 dition, not concerned about a normal condition. In 9 that connection, speaking of being a risk analyst, 10 I'm -- MR. GIBSON: Could I inter- ! tj t ject for a second? , [2 MR. GARRICK: Yes. 13 MR. GIBSON: I heard some- , 14 thing that didn't seem correct. You said that if we 15 1 st the BWST, we would lose the HP and LP pumps or 16 their capability. 37 MR. GARRICK: Well, in the ' 18 bsenca of -- yes, I think so. We would lose the 19 apability. . 20 , MR. GIBSON: Okay. At first 21 I thought you were saying they'd destroy themselves 22 a d I'm thinking, well, that assumes that they're 23
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I running off the BWST, which is not a hundred percent 2 assumption. 3 MR. GARRICK: In that specific-r 4 part of the question of whether or not there is any 5 low Pressure protection. 6 MR. GIBSON: But they, in 7 fact, you would need to lose that tank and have a ECCS . 8 signal in order for that loss to occur. 9 MR. GARRICK: Weil, you'd 10 Probably get an E CS signal if you had a seismic event. 11 You'd probably get that safeguard actuation. MR. GIBSON: That's possible, 12 13 Possible. , MR. GARRICK: Possibic. Well, 14 it depends on the earthquake. 15 MR. GIBSON: We don't have a 16 seismic switch. Thank you. Go on, now. 17 18
" * ^ ' '* )"' #Y "9 d
to develop a feel for the extent of the analysis and 39 what the levels of these different systems are. In 20 evalua Lng the real threat to the systems, that kind of 21 I information becomes ir.portant, but what I was going to ' 22 Comment on is that the truth is I'm having trouble 24
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I getting over the first hurdle and the first hurdle is 2 what has cold shutdown under prescribed conditions got ! 3 to do with risk? I'm not convinced that it has much to 4 do with risk and I realize that's not what we're addressing here. What we're addressing is the adequacy 5 6 of the design to achieve cold shutdown, and I was , 7 encouraged by Jerry's comment. I think the context was 8 more of its capability than thou shalt achieve within g a period of time and under certain load conditions such as a safe shutdown earthquake, because those kind of 10 33 conditions are extremely arbitrary and, as a matter of fact, in a scenario sense and the frequency of occur-2 rence of scenarios, it may turn out that they don't 13 g add safety but could even conceivably add risk. We have to be prepared for that kind of an evaluation as 15 16 When you talk about safety grade g systems, again, that's kind of an arbitrary thing, 8 especially from a risk standpoint because experience g I is telling us that as far as risk is concerned, there ' 20 seems to be very little difference between seismic category one components and non-seismic category one. l
)
22 In other words, those differences do not seem to be 23 .
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HURON REPORTING SERVICE j 7615328 I l
1 visible in the fragility curves a.ad so the truth is, 2 when you're faced with wanting to cool down 'rou ought 3 to have everything at your disposal, available 4 to you to achieve that and to create the state of mind 5 that says that you've got to get there by way of 6, safety grade equipment may not only not be the best way, 7 to get there but could create an unsafe condition. 8 MR. MAZETIS: Just one piece i 9 of actually what you're talking about, John, it's my i 10 understanding that in the RHR suction, there is a valve i 11 outside containment that's motor-operated. My question 12 is, during normal shutdown cooling, isthepowertothalt 13 valve removed, and if not, the question is', is there a 14 1 w fl w alarm in the RHR system lines to alert the 15 perator to a condition where the valve was inadvertent-16 y sed? j7 MR. HUGHES: Gerry, you're talking about a valve outside containment? 18 jg MR. MAZETIS: Right, in the RHR suction, a common header with a single motor-20 g operated valve. MR. PRATT: The valve is 22 locked open. The operator will not be in place, okay, 24 -140-HURON REPORTING SERVICE 7615328
- 1. so functionally, I'd call it a vestigial organ much I
2 like an appendix. It's there because, from the stress 3 point of view, it was easier to leave the valve in 4 place than to take it out, but the valve is locked open. 5 And let me clarify, if the operator has not been re-6 moved or will not be removed, the pcwor supply will be 7 removed and that description of the design is shown on 8 the P&ID. I believe there's a note on the -- 9 MR. TAYLOR: Yes. The FSAR 10l drawing has a note for that system which says the motor 11 operator on this valve is not connected to any control 12 or power supply or power circuit. 13 MR. HUGHES: The original, 14 design had a motor-operated valve and the consideration s 15 of enhancement, rather than cut out the valve already 16 installed, it was merely disabled. I 37! MR. MAZETIS: Okay, and you don't have icw flew alarms in the RHR system? 18 gg , MR. HUGHES: Mike , can you anster that? 4 0 g MR. GERDING: Yes, we do havo l 1 w fl w alarms in our system. In fact, there is a low 22 flow interlock to the DHR pump which wall trip it in 24' -141-HURON REPORTING SERVICE 7615326
- c. . _ _ _ _
1 the event of a low flow. This equipment is there for 2 normal operation. It's not a safety grade function. 3 During the emergency core cooling 4 actuation, these systems are bypassed in the circuitry. 5 MR. GARRICK: I have just one 6 m re earthquake kind of question because I was trying 7 to work up a couple of scenarios. It's possible that 8 an earthquake will result in an extended loss of off-g site power. Can you tell me if the following itams are powered from the diesel generator buses; for example, 10 gj the instrument or control air compressors? No? i The diesel generator fuel oil transfer , 12 P mps? 13 MR. BALLWEG: Yes. 4 MR. HUGHES: Yes. 5 16 auxiliary feedwater, feed only one good generator logic. MR. BALLWEG: It's off the 18 DC. lE, DC preferred, AC preferred power system, yes. g, MR. GARRICK: Yes. 20 MR. BALLWEG: Batterv^ ' cack 21 and DC. 22 MR. GARRICK: The instru-23 mentation and control power providing pressure 24 l: i
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--r- -
1 interlocks on DHR cooldown isolation valves? 2 MR. BALLWEG: Yes, it's all 3 lE. 4 MR. GARRICK: DHR heat ex-5 changer cooldown bypass valves? 6 MR. GERDING: Let me -- 7 MR. HUGHES: John, can you - 8 wait a minute and let's take a check on that one. 9 MR. GERDING: Yes , let me 10 check that one and I'll get back to you. 11 MR. GIBSON: Could I ask a 12 question? Are you through with the list? I just want 13 to elaborate on one. If you lose the instrument air 14 e mpressor, is there a figure of merit or whatever for 15 how long you'll have the instrument air? 16 MR. BALLWEG: Nothing that 37 will be defensible. MR. HUGHES: We don't, Lou, 18 39 I believe it's true that we take no credit for the pera n. 20 MR. BALLWEG: That's right. 21 We take no credit for it. 22 MR. HUGHES: For the 23 24 -143-l '
! HURCN REPORTING SERVICE 7615329
r 1 instrument air system for safety requirements. 2 MR. GIBSON: So it's not 3 really used for any of the things that we talked about? 4 MR. COOK: -I think that gets 5 back to John's point about -- how about in terms of 6 what your real expectations are for that supply? ! 7 MR. HUGHES: Jim, we're , 8 really demonstrating a capability against a require- l i 9 ment using lE so that while there are a great number
?
10 of other features, the plant that we would hope and 11 expect to be available in the process of demonstrating I the capability, we take no credit for them. The 12 negative is not true, that, therefore, they are useless 13 , and not available. j 14 MR. BALLWEG: We have the 15 answer to that DHR bypass valve. They do, in fact, 16 get diesel power. 37
" ~ ^ * "Y 9" 18 , )g from the diesel buses? ;,
f ' MR. BAttwEG: Yes. ;
,g MR. TAYLOR: And the two are separate; I mean, one for each cooler? There's no way that they are common?
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j MR. BALLWEG: That's correct. 7 MR. SLADE: Are we ready to 50V8 "2 3 . MR. COOK: Okay. John, do you 4 want to follow? 5
. A RICK: No, I'm fine.
6 MR. COOK: Okay. 7 . MR. SLADE: I have a question 8 that's unrelated to what we've discussed so far, I g . think, but in reading the text in preparation for the meeting today, in the written presentation on page 9, there + w some discussion that the PORV will in fact 12 prevent a reactor trip from occurring. I thought that I had understood previously that we had changed the logic on those so that we would, in fact, get a re-actor trip before the PORV's came open and that in 16 addition -- no? I see a lot of heads nodding. Could we review the current design 18 state of what the order, the sequence is of power-19 operated relief valves, RPS trip and pressuriser 20 safeties? 21 MR. IIUGHES : Jim, is this 22 appropriate for you to answer? i 23
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k 4 1 MR. AGAR: Well, let's take 2 them one at a time. Would you ask your question one ; i 3 more time so we can make sure we got it? I MR. SLADE: Okay. I would I 4 i 5 like to know what the sequence of operation is for the ! 6 power-operated relief valve, the set point, the set , i r 7 point for the reactor protection system trip and the 8 set point for the safety valves on the reactor coolant [ 9 system. What is the sequence of operation? MR. AGAR: Bob, can you > 10 11 answer that, Bob Schomaker from B & W? , MR. SCHOMAKER: Yes. The
]2 .
13 n rmal operating pressure for Midland plant is twenty-two hundred pounds. If one was going through a rise in 14 15 pressure, one would first see a PORV open around i twenty-two sixty, which was shown in one of the previous 16 slides. The RPS trip set point is currently twenty-97
*** Y~ E" 9' 18 MR , SLADE: I'm sorry?
19 MR. SCHOMAKER: Twenty-three 20 g fifty-five psig and the pressurizer safety valves are set at twenty-five hundred psig and they'would open in that order. These are typical pre-TMI type set points. 23 I 24
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.-,-7 . -
cr ,__-.,7 ,,-y ,.,,r._7.-.v, -.97..,,-.4 p..-.r.r-- - < -- . * ,-
1 MR. SULLIVAN: Well, they're 2 also post-TMI set points. 3 MR. SCHOMAKER: For Midland, 4 that's correct. 5 MR. SULLIVAN: And for the 6 other, a similar t.hing for the other -- the 205, the 7 other backlog B .i W plant. 8 MR. SCHOMAKER: The 205 9 plants have a higher high pressure trip set point than 10 twenty-two fifty. 11 MR. SULLIVAN: Similar 12 sequence? 1 MR. SCHOMAKER: Similar i 13 sequence, that's correct. 4 14 MR. COOK: Jerry, do you j 15 have further pursuit of that issue? 16 MR. SLADE: No, that re-37 solves my questions. g This may not be appropriate at this 19 4 ' meeting -- if it's not, redirect it for tomorrow, I 20 guess, I 21 MR. COOK: Okay. i- 22 1 MR. SLADE: Again, on page 11 , 23 24 -147-HURON REPORTING SERVICE 7615328
1 they discussed the auxiliary feedwater suction switch-2 over and in some of the review materials, there was 3 reference to a four second time delay on the switch- -l 4 over of that service water supply after the AFWAS and ! t 5 low pressure, low suction pressure signal was available . I 6 I'd like to know what the basis for the four seconds [ 7 is, whether it's pump protection or whether the four . l-i 8 seconds is based on the need for the cooling water to ; i 9 the steam generators. \ 10 MR. HUGHES: Tom? 11 MR. BALLWEG: Four seconds is based on two considerations. The i- ;damental ' 2 consideration is to minimize the possibility of in- t 13 advertent actuation of service water that you might 14 . have during a pump start. You'll have a decrease in 15 suction pressure any time the pump starts. ! 16 i
, MR. SLADE: My concern is :
17 why not four hours instead of four seconds? Why not 18l 39 less than four seconds? MR. BALLWEG: The second is 20 the forty second requirement that B & W has imposed 21 t 22 f r establishment of aux. feedwater flow to the steam l generators after initiation of the demand signal. i r
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l 1 MR. SLADE: Forty second? 2 MR. BALLWEG: Forty seconds.
~
3 MR. SLADE: Again I'll ask 4 my question. Why do we have a four second time delay 5 instead of a forty second time delay? l! l 6 MR. BALLWEG: Because it 7 takes time, the auxiliary feedwater pump is sequenced 8 onto the diesel gener.cor. The combination of its 9 sequencing and twenty-five seconds plus ten seconds 10 for the diesel generator to start leaves you at thirty-11 five seconds. I would like to beat forty. That leaves 12 me five seconds, so I took four. 13 MR. SLADE: Okay. So it has 14 to do with the start sequence logic? MR. BALLWEG: That's correct. 15 MR. S LADE: And it is based 16 on flow to the steam generator, not on pump protection? 37
)g MR. BALLMEC: That's correct. )g MR. S LADE: Thank you.
MR. COOK: And I think we've 20 finished our preliminary questions now. 21 MR. TAYLOR: I have a couple 22
" #8' 23 I
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1 1 MR. COOK: Whoops, sorry. 2 MR. TAYLCR: I'd like to shift i 3 over to auxiliary spray again, shift back to it. In 4 the write-ups that we had, there was something about 5 the number of cycles that the auxiliary spray system 6 could be actuated and I heard, I think, Mike say that 7 this system is designed for forty cycles. 8 MR. PRATT: I believe I was [ 9 talking about the emergency -- t 10 MR. HUGHES: No, Mike was t 11 talking about the decay heat removal system analysis [ 12 for 325 based on one cycle per year. i 13 MR. TAYLOR: Where do we l 14 stand on the spray nozzle coming into the top of the 1 15 pressurizer and the rest of that in terms of number of cycles? ! 16 MR. FRATT: Well, I believe 17 18 B& W can best address that. My understanding is that 19 the analysis is ongoing. MR. HUGHES: It's in progress, 20 r at this time and I guess I'm going to ask Jim Agar to j 21 comment upon it. We have not received results yet. 22 MR. AGAR: The answer is as 23 r 24 -150-si HURON REPORTING SERVICE f 7615328 7 i L t __ ~ _ _ . _
1 given; the calculations are being done right now, Jim,
'2 in-house.
3 MR. TAYLOR: I'm a little bit 4 concerned about that line, that when we tie into that 5 big line which normally comes up from the reactor 6 coolant pumps and the flow coming from the auxiliary 7 spray line is going to be very low. The curve, I 8 think, one curve said five or ten gpm, something like that. I'd like to know, har the evaluation included 9 or does it have plans to look at the effects of that 101 jj very, very low velocity coming through that big line, and whether or not, just in the course of normal 2 13 peration, that spray line could be partially full such that if you have five gpm or so coming in and 14 running into the pressurizer spray line, could the 15 nozzle and + Se piping have a very potentially adverse circumferential temperature variant such that the g bottom half of the line micht be at 50* or a 100", 18 whatever, and the top be subjected to steam from the g 9*'# "* ***? l 20 . If that hasn't been looked at, I 21 would like to suggest that it be looked at and as a part of that, also, to find out whether or not the
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1 effectiveness of the spray, itself, where that line is 2 normally designed for, I don't know, fifty or a 3 hundred gpm, to have five or ten gpm coming into it, i 4 whether that will really effectively promote heat 5 transfer in the pressurizer between the subcooled L 6 vater and the steam space so that you get an effective ! 7 depressurization. So the first question is, does the 8 analysis that is ongoing for the number of cycles on g both the piping that Bechtel is doing and the surge line r the spray line nozzle in the pressurizer that 10 B & W is doing look at the possibility of a partially j 11 filled line; and the second one is, is the effective- ; 12 i ness of the st:ay water, that big nozzle, what con-13 fidence can we have that you will really have complete ; 34 heat transfer between the subcooled water and the 15 16 MR. AGAR: Well, I'll address g , the -- since I was talking about the B 5 W calculations, Jim. The only thing that we're going ta address is g the nozzle in the pressurizer, itself. To my knowledge , we're not considering partial flow through that nozzle. Is that right, Bob Griese? Do you concur with that? . t
. 22 The results of our calculations 23
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l 1 using the auxiliary spray system is confined in the - k 6 i 2 1092 spec and I don't believe there is any restriction 3 in there or any consideration being given to partial li 4 flow through the nozzle. I won't address the Bechtel ; f 5 Fart of the lines, where the lines connect. That's a r
'l 6 Bechtel consideration.
MR. TAYLOR: Well, I'd like , 7 8 to know why not because it seems like it's a real 9 possibility, particularly if the line is perfectly 10 level coming into the top of the pressurizer and then ( coming down. It seems like the possibility exists j 13' that the line could be partially filled with a very ; small flow to a fairly large line. 13 MR. AGAR: Well, let me try 14 15 something, Jim, before -- Bob Griese, could you address 16 that question now to get it on the record or should we 1 97 wait until later to address that?
.c MR. GRIESE: It would be 18 better if we addressed that later when we have at leas *e j 19 some drawings to demonstrate the configuration inside 20 i the pressurizer. The nozzle is not just a simple 21 elbow coming into the nozzle pressurizer, but I didn't 22
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l l 1 MR. AGAR: We cannot address 2 that now, then. We'll have to take that as an open 3 item, I guess. 4 MR. SULLIVAN: Well, I'm 5 relating that back to your first question which was 6 the first action item on this same subject. 7 MR. TAYLOR: It's an exten-8 sion, really, of that. One of the problems that could g come from that is that if the calculations assume that 10 the spraywater is completely mixed in the pressurizer 11 and it's not, then you could have to inject more 12 water than you had counted on and thereby use up more 13 of the available volume than you really counted on. 14 If you don't have the letdown flow, 15 y u might not accomplish the desired depressurization us ng de p rtion of the volume you had available. 16 MR. HUGHES: Tom Ballweg? 37 an I ask a 18 jg question to that or - if you've got steam over uater, you are going to have energy transport across that g interface and so the water temperature will be virtua'.ly instantaneously the same temperature as the steam above it, will it not? i 24' -154-i i l HURON REPORTING SERVICE 7615328
l 1 MR. TAYLOR: I don't know. 2 MR. BALLWEG: Well, in 3 general, it is. 1 4 MR. TAYLOR: If it's spray, 5 certainly, yes. 6 MR. 3ALLNEG: Well, even if ( 7 you're talking about a pipe with a half of an inch of .l 8 water in it and two inches of steam or even vice-versa 9 or maybe half-and-half, the energy transport across 10, that face, steam condensing onto the water is a very, 11 very rapid phenomenon and your question about requiring
- \
12 r e neern about requiring more water to depressurize [ i 13 rec gnizing the very high rates and very high heat ' 34 transfer rates across the steam water interface, direct 15 contact heating, I don't really understand the basis 16 g MR. TAYLOR: I'm concerned about two aspects of it. If you just had a cylinder g; and the bottom half of the cylinder was filled with l , Cold water and there was steam above it, the stresses would be very high on the top and there could be a lot of stress built in to make it look like a hotdog. How far back the piping you might have to go before you
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! HURON REPORTING SERVICE 7615328 !
l 1 say I've completely raised the water up to saturation 2 temperature, I don't know. It's a question, really, 3 and then if you -- however far back you have to go, 4 that ought to be considered in the design of the piping ' to see if it will meet the number of cycles that the 5 6 system is designed for, and the other part is whether 7 or not there is good heat transfer between the steam . [ 8 and the water, but whether it's good enough is the g question. It certainly is excellent as you break it 10 up into smaller and smaller drops. MR. BALLWEG: Yes, I agree 11 with, the first part of your concern I take no issue 12 with. The second part -- 13 MR. COOK: Okay. I think 14 we're g ing to have to go ahead to try to proceed. 15 Jim, do you have more questions you want to get on 16 the floor? 97 MR. TAYLOR: Is there a 8 flow meter in that line such that you can tell what
)g the auxiliary spray flow is or are you just relying on pressure reduction?
MR. PRATT: Okay. There is 22
- no flow instrumentation in that line, no_ .as it t :23
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_ ~ _ _ _ - . . . _ . . _ ~ . . _.. -
1 considered to be a design requirement. The operator 2 will monitor the cooling, the depressurization rate , 3 and then adjust the throttling valves to control that ; 4 depressurization rate, essentially by using a direct 5 variable rather than an indirect variable. l , I + 6 MR. S LADE: You say adjust , 7 the valve. Is that an adjustment in the control a center? e 9 MR. PRATT: Yes, yes, remote 10 manual throttling of a motor-operated globe valve. l 11 MR. HUGHES: And again your 12 assumption here is depressurization. 13 MR. 3 LADE: Pressure control. d j4 MR. HUGHES: So that you w uld be reading pressure. 15 i MR. LOOS: I've got about 16 l three questions. One, as I read the B & W cold shut-g . wn umen s, there is a concern about the core flood 18 r tank and the ability to isolate that in a safety grade 39 1 manner. With the current arrangement of the single valve, how are we going to establish we don't get g dilution by core flood, and then the next question -- 2 MR. HUGHES: Shall we answer 23 , f 24 -157- ; i I h l HURON RnPORTING SERVICE 7614328 ; l
I that first? 2 MR. LOOS: Yes, why don't we 3 answer them one at a time. 4 MR. PRATT: Yes, we've con-5 sidered the potential for a singic failure of the core 6 flood tank isolation valves, specifically the event i 7 that you could not get it closed and, therefore, when 8 you depressurized to 600 pounds, you'd have an insurge 9 of core flood tank contents, which B & W had told us 10 would not be acceptable in a cold shutdown scenario. 11 Therefore, we have added the design capability to vent 12 the core flood tank nitrogen gas in the event of that 13 single failure. 14 MR. LOOS: Okay. With respect 15 to the scenario where using the boric acid addition 16 tanks as a means of making contraction volume, you have 17 the three tanks, is there going to be a low level re-18 quirement on those tanks that will eventually end up 19 in a technical specification or something like that? MR. HUGHES: We can speak to1 20 21 the design. MR. PRATT: Yes. There will 22 be a need for a tech spec to maintain approximately 23l 24 -158-f i HURON REPORTING SERVICE 761 5328
1 sixteen thousand gallons per unit. There are three 2 boric acid addition tanks of ten thousand gallon 3 capacity each per unit. There will be a need to main-4 tain slightly over sixteen thousand gallons per unit, 5 so just less than two of the three tanks will have to 6 be available. MR. LOOS: Okay, and the other 7 8 one is that with respect to your makeup tank, that has g got a nitrogen or a hydrogen overpressure on it and 10 if y u 1 se the capability to provide the nitrogen or 33 hydrogen, is that going to affect any of your pumping capability? 2 MR. PRATT: We're going back 13 and looking at the NPSH calculations fo the makeup 14 pump to verify that we will have adequate NPSH in the 15 event that you are drawing from the makeup tank and 16 you've lost the nitrogen or hydrogen overpressure, and 97 I can't comment yet on the results. g MR. HUGHES: The results of g
~~
20 MR. PRATT: I believe we will 21 have adequate margin but that hasn't been documented Y 23
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1 MR. COOK Mr. Jensen? 2 MR. JENSENs Yes. In adding 3 the manual vent lines from the flood tanks, have you 4 looked at the possibility of inadvertent opening of the 5 vent during the LOCA? 6! MR. PRATT: Not specifically. 7 I guess the scenario you might consider is a jet 8 impingement on the vent line or something like that? I 9 MR. JENSEN: Well, the 10 operator just opens it, makes a mistake and opens the 11 valve. 12 MR. PRATT: Okay, during the 13 LOCA or --? 14 MR. JENSEN: During the LCCA. 15 MR. PRATT: Well -- 16 MR. COOK: Loss of original 17 primary safety function due to the new add-on. ' 18 MR. PRATT: Any isolation, jg any venting path that we provide will have two valves. 20' MR. JENSEN: So couldn't he open up both valves at once if he wanted to vent it, if he opened both the valves? 22 MR. PRATT: Not through a 23 i 24 -160-HURON REPORTING SERVICE 7 e t.53 2 8
i I single control. 2 MR. HUGHES: Mike, are you 3 saying that the vent path will have two valves and that i 4 each one will be individually controlled? ' r t 5 MR. PRATT: Yes. r MR. HUGHES: Okay, and we i 6 7 don't design for multiple operator errors. ! MR. PRATT: The operator can- ; 8 9 not just throw one switch and open both valves. He would have to deliberately this one and this one. , 10 , MR. SLADE: Just a point of j; clarification there. You're not concerned with having 12 ' i that tank vented normally until you're at a much lower 13 14 pressure. You're not going to be inserting those i tanks into the system until you're down to, what is it, 15 about 600 pounds? 16 MR. PRATT: Six hundred 37 p unds, right. 18 MR. SLADE: So that you have 19 a lot of time under normal Circumstances before you ever get jc that 600 pounds and the operator does it, 21 so it',s not the kind of thing that the operator is , going to immediately respond or have to make a quick
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h I 1 action to turn those valves? ? MR. .PRATT: Right. 2 MR. SLADE: I guess I'd like i 3 I , 4 to pursue that line of logic a little bit farther and l l ask whether those switches are key-operated switches or-5 whether they're just normal manual switches. Is it j 4 6 7 something that the operator has readily available to , him er is it something that has an administrative con-8 g trol associated with it? MR. HUGHES: I'll have to 10
- gj ask Mike Gerding for that and I don't know whether the l r
design has progressed to the point of the exact type of l l 2 switch, have we? g a MR. GERDING: The design has , 14 ! not been finalized. The choice of the switch has not 16 been made. The consideration for administrative con-16 trol, we have to go into that process of determination 7 of the switch. That's about all I can say about it. [ 18
' MR. JENSEN: I think it would: 1 19
) be important to have some positive indication to the j 20 operator whether or not the flood tank, the flood tank 21 was isolated by the single valve that does exist before 22 I he would take this additional step to vent the flood , 23 l tank. l 24 ;
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t i HURON REPORTING SERVICE , 7615328 t i i
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- .- - -_. ... - -. ..- . . . ~_ .- .
l 1 MR. HUGHES: Walter, are you
- 2 suggesting that we have a position indication on the 3 valve, is that the -- l i
4 MR. JENSEN: I would think it would be -- well, I was wondering, instead of having 5 the operator. as he goes down this, brings the plant I 6 f 7 down -- 1 g MR. HUGHES: Down to 600 t i 9 . pounds. ,
' t MR. JENSEN: In this >
10 i scenario of depressurizing the system, would he
. 11 ,
r utinely vent the flood tank or would he do it only {2 13 if he had some indication that the isolation valve that was in place was not closed? 14 MR. HUGHES: It is certainly j 15
! the designer's expectation that he would only vent the 16 g tank where he had indication that the valve was other than in its expected position.
l g MR. JENSEN: So, then, there 19 would be some indication, then, on this flood tank? MR. HUGHES: Now, the 21 specifics, Mike, do they have a position indication? MR. GERDING: Right. The 23 24
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. _ = _ . - . - - - _
Y t I core flood tank outlet valves have indication provided 2 toth from geared limit switches on the motor-operated 3 and stem model limit switches, both inside the control 4 4 room.
.o.
5 MR. S LADE: Also there's 6 indirect indication in that for a slow leak you would 7 see a reduction in the core flood tank level which , would cause another alarm to alert the operator to the 8 9 fact that he had a problem, correct? MR. PRATT: For a slow liquid 10 3; leak. MR. SLADE: Yes, as the level 12 f the tank went down, there's also another alarm to 13 the operator that identifies to him that he has a 14 i E# 1*"* 15 7
- MR. PRATT: Or low pressure.
16 MR. GIBSON: I think the j7 practice scenario, it is a cooldown scenario that ue're 8 g concerned about where that valve fails to close when you ask it to. It's one where you are deliberately causing the pressure to come down in the plant and those core flood tanks will start to bleed in. They won't blast in because your pressure differential is l 24
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l l 1 starting at zero and increasing, so I would envision, i 2 like Jerry says, if you started to see a lack of posi-3 tion by two sources, a level decrease followed by a low 4 level alarm, you would have indication that your tank 5 was starting into the system and that's when you'd start into this venting, I would think. I haven't done ; 6 7 it. 8 MR. SLADE: Normally during 9 a shutdown sequence, again we're talking several hours [ into the sequence, normally during the shutdown sequence, 10 by that time the operator -- the control center has j 11 [ quieted down from all of the alarms that flash on 12 immediately. He's pretty well resolved what his status
- 13 is at that time. l 14 MR. HUGHES: Jim, based on 15 a s gs, in a uple f inutes, that.
16 we do brr3F 'er tanc h . Are there some more questions 77 t we might -- , 18 MR. COOK: I had hoped that g w, y know, could resolve che questions on this area l 0 because we need to get onto the other presentations. l 21 ; I would like to ask the board if there are any burning i 22 questions they would like to get in as one last shot? , 24 -165- , . HURON REPORTING SERVICE 761 5328
~ ,v- - - - - - . - -%-, , , . _
1 MR. SLADE: I have one burning - 2 question and last shot. 3 MR. COOK: Burning? 4 MR. SLADE: That arose as a 5 result of another question and that is that if we are 6i 1
.equired to have sixteen thousand gallons per unit f 7 available, that was -- what did you say -- one, two 8 tanks?
9 MR. PRATT: Just less than 10 two tanks. MR. SLADE: Oh, it's less than
-11 l2 two tanks?
MR. PRATT: Right, of the 33 three. 14 MR. SLADE: All right. My 15 burning concern just went away. 16 MR. COOK: All right. How 37 much do we allow for lunch here, and I think we better 18 , s jg be brisk about it.
* ** Y
- 20 g
to get back here at 1:00 if we break right now, because we have a lot more to cover and would like to plan on, if there is no further questions on this section, we 24 -166-HURON REPORTING SERVICE 761-5328
i l 1 start on -- MR. COOK: Start right in. I 2 , I I MR. HUGHES: Fine. 3 l MR. COOK: One o' clock? 4 Thank you, gentlemen. 5 i I i 6 7 8 9 10t l 11 I 12 13 14 15 16 i 17 l l 18 f, 19! 20 21 22 23 . i 24 -167- i t HURON REPORTING SERVICE 7615320
1 2 CERTIFICATE OF NOTARY PUBLIC 3 4 I, Susan A. Simpson, of the firm of 5 i HURON REPORTING SERVICE, a Notary Public within and for the 6 t County of Wayne, State of Michigan, de hereby certify that I 7 reported stenographically the foregoing proceedings con-8 sisting of (167) typewritten pages and is a full and correct 9 transcript of my stenographic notes so taken. 10 11
~ '
< r -
12 - DATED:' OQ I' I '1 Y J Oe t 4 c. Ni . ,. - . (. Susan A. Simpsos~ l 13 ~ Certified Shorthand Reporter 14 15 16 17 18 19 20 i 21 22 23
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l HURON REPORTING SERVICE 761 5328 _ _ - . _ , . . . _ _ _ - _ . . _ . _ . . _ _ _ _ , _,,.}}