ML20106C191
| ML20106C191 | |
| Person / Time | |
|---|---|
| Site: | 05200003 |
| Issue date: | 06/15/1992 |
| From: | Schrock V CALIFORNIA, UNIV. OF, BERKELEY, CA |
| To: | Catton I Advisory Committee on Reactor Safeguards |
| References | |
| ACRS-CT-2028, NUDOCS 9210060082 | |
| Download: ML20106C191 (11) | |
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Dr. Ivan Catton, Chairman June 15,1992 Themul flydraulics Subcommittee Advisory Committee on Reactor Safeguards US Nuclear Regulatory Commission Washington, DC 20555 j
Re: NRC RES & NRR / INEL / JAERI Joint Meeting on AP 600 IFT, June 3&4,1992
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Dear Ivan,
The meeting was chaired by Dr. Brian Sheron. The parties were RES and their consultants Peter Griffith and Brent Boyak, NRC Contracts, INEL, JAERI, and Westinghouse. Obse. vers from ETEC, EPRI, and DOE ID as well as the three ACRS consultants were also present. (The attendance list is attached.) In opening the meeting.
Dr. Sheron noted that it was not an open meeting and that discussion / questions would be limited to those seated at the table (RES, INEL, Westinghouse, and JAERI). lie did, however, occasionally ask if observers had any questions or comments.
De purpose of the meeting was to review ROSA -IV design changes for the NRC AP - 600 IST pmgram and to reach agreement on instrumentation and the test matrix. In his opening remarks, Dr. Sheron explained that it was not the intent of the program to achieve full simulation of the AP - 600. The purpose of the ROSA -IV experiments is to obtain large scale test data, including the phenomena expected in AP -600, for use in code validation...He gave a brief historical review of the SEMISCALE and MIS ~l programs.
M. Ortiz, J. M. Cozzuol, J. E. Fisher and S. M. Sloan of INEL presented results of RELAP 5 MOD 2.5 calculations of responses of AP -600 and ROS A - IV in selected transients. MOD 2.5 was used because of problems with MOD 3, however they think MOD 3 problems have been resolved and are now to use it. Ortiz described an in house INEL PIRT study in the context of code assessment needs. B. Boyack was critical of the PIRT repon he had seen. Ortiz stated that it was only a draft and will be improved. Ortiz 9210060082 920615 rr.~ r n m a m.
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Page 2 pointed out that ROSA - IV is 1/48 scale of PWR and 1/30 (16%) of AP -600. ROS A has only one CMT compared with 2 in AP 600. Ortiz' slide # 18 summarized the " levels"(l st,2nd & 3rd) of ROS A. IV modifications. Sheron had already commented that the System modifications had already been pretty well decided in precursor meetings of the principal parties. Based on the draft PIRT and system study, representative transients wc chosen as follows:
- 3 inch break in cold leg
- I inch break in cold leg
- 3 inch break in Pressure Balance Line (PBL)
- SGTR - I tute
- STGR - 3 tubes
- MSL break Cozzuol presented the comparison calculations for the two cold breaks. He concluded that level one modifications would be sufficient for 3 inch break simulation (qualitative ) of AP - 600 for system response and passive safety feature behavior. For the 1 inch break, ROSA - IV and AP -600 would be different. lie suggested that modification of upper head flow paths and additior, of full length pressurizer would improve the situation. There was considerable discussion on both items. T'iere are obviously modelling problems related to the upper heads in these systems. In addition ROSA is much higher than AP-600 and there will be difficulty making the flow paths in ROSA typical. Dr. Shotkin argued that it is not necessary to change the pressurizer height because it does not change the phenomena involved. De obvious pmblem here is that the process being pursued assumes that RELAP 5 is capable of capturing the phenomena in both systems. An example of where this may be untrue is the mixing that could be caused by jetting of the steam into CMT with consequent rapid condensation. His potentially important phenomenon is not well modelled in RELAP 5, in my opinion. Suppose it is not seen in ROS A - IV. His would provide no assurance that it will not be important in AP -
600. The atypical tube wall thickness in ROS A - IV SG was also cited as a reason to modify the SG.
Fisher presented the comparisons for SGTRs. Collapsed liquid levels are quite different. The CMT drains faster in ROSA. Shemn is concerned about overfdl while l
Hochrciter says they never get overfill. Level one modifications will be sufficient to l
preserve the phencuna but results will be more typical if ECC lines are modified to give correct friction losses and the scaled pressurizer is added.
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Page 3 Sandra Sloan presented the PBL break results. Results look similar but she notes that this is fortuitous since the causes are different. Use of a single CMT causes atypical condensation in PBL. This looks like a major problem. Cold leg geometry differences also appear important. Core heatup is calculated for ROSA but not seen in AP 600. The second CMT is needed for this scenario, ne enlargement of upper head flow paths is needed for this scenario.
Cozzuol reviewed the comparison for the MSLB. Concludes that the level one modifications are adequate but the simulation would be improved with that addition of the full length SG.
Ortiz presented the overall INEL conclusions. A copy is appended to this report.
D. Bessett presented the proposed test matrix (copy attached). Phase I included 12 tests in four general categories. Phase 11 would consist of 6-12 tests to be identified as phase I results become available, ney might be repeat tests or investigate beyond DBA scenarios. During the discussion '. Griffith suggested using a scheme based t.pon void fraction. A. Levine said it would be dangemus to omit the single phase part of the transient because what happens in two phase depends on how you got there. lie also suggested a priority ranking and modification of the test matrix. I'm not clear on whether his suggestions were adopted. During this discussion JAERI indicated that they planned to put the steam from the ADS to drive a condensing jet pump. His has the potential capability to measure the ADS flowrate and enthalpy.
M. Modro presented the INEL recommendations on equipment modifications Basically they suggest level 1 plus 8 items (listed in the slide, enclosed).
D. Mecham presented the INEL assessment ofinstrument requirements. More information is needed from Westinghouse on how heated TCs work in actuating the ADS.
Impedance probes for filtn thickness bmught objections from Griffith and Ilochreiter.
Three beam gamma densitometers, drag disks, catch tanks, turbine meters, DP transducers all were suggested. De estimated cost was in the range of $2M, but a disclaimer was included indicating that it was not a commitment to provide.
JAERI presented some cost estimates for the modifications to ROS A - IV. The cost is estimated to exceed $6M, as I understand it, without complete elimination of the loop seal. Despite strong urging by Griffith, Hochreiter and others to eliminate the loop seal, Dr. Shemn said that he and Mr. Beckjord are not prepared to provide the necessary
$151.5M necessary for this modification. Westinghouse would have to present more persuasive arguments in favor of this expenditure.
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Page 4 Some action iterns were identified as follows:
- 1. Design scaled surge and pressurizer intemals (1 mo.)
- 2. Provide time to ADS valves to J AERI.
- 3. Identify why clirnination ofloop seal is so important. If they object to 0.4 m loop seal, give their reason 4.
- 4. Provide data on heated TC's in CMT, INEL
- 1. Analyze reduced loop seal-two cases.
- 2. ?
- 3. Find method for measuring ADS flows.
- 4. Finn up instrumentation recomnwndation, it remained unclear to tre what role RES has in mind for INEL. It is not clear that the Japanese can do what is needed without help from INEL or someone.
JAERI
- 1. Provide recommendation on Test Matrh.
- 2. Provide firm JAERI costs for items 1,2,4,5,&*. These werr said to be needed for Commission report and for contract.
The nreting was declared adjourned at the end of the noming on June 4. Dr.
Sheron said he would meet in closed session with key representatives of JAERI and INEL in the aftemoon to work further on instrumentation, cost estimates and test matrix questions. It appeared that he wanted to get an agreement signed with JAERI before departing Idaho.
My view of the situation was left somewhat 2ncertain. It appears that the RES plan to use ROSA IV will be pressed forward. I had a hard time understanding significant parts of the discussion and therefore feel that I need more information to comment fully on the program. On the other hand, I was not persuaded by this meeting that it is a good idea to use ROSA to meet the AP - 600 IST needs. My intuition tells me that NRC will later regret having gone this route, t
Sincerely yours, Uf m/
vdl E. Schrock
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Particiguiti P.oposed Modifications to the ROSA LSTF Facility for AP600 Safety Research Heeting, June 3rd, 1992 NAME AFFillATION pHQR[
Baxin, Joyce NRC/ Contracts (301 492 7182 Bessette, David NRC/RES (301 492 3572 Boucher, Tim INEL (208 526 9213 Boyack, Brc ' E.
LANL (505 667 2023 Cozzuol, Jim INEL (208 526 9901 Ohir, Vijay UCCA/ACRS (310 825 8507 Fisher, Jim INEL (208 526 0571 Griffith, Peter HIT (617 253 2248 Hanson, Duane J.
INEL (208 526 9751 Harvego, Ed INEL (208 526 9544 Hassell, Donald NRC (301 504-1550 Hoehreiter, Lawrenn E.
Westinghouse (412 324 5158 Kukita, Y.
JAERI 292 82 5263 Lake, James A.
INEL (208) 525 5518 Levin, Alan NRC/NRR (208)5269634 (301 504 2890 MacDonald, Philip E.
INEL (301))4924297 Mace, Mary NRC McDowell, Michael ETEC (818) 586 5256 Hecham, Del C.
INEL (208))5268756 Modro, S. Michael INEL (208 526-9402 Naff, Sem INEL 208) 526 6926 Ortiz, Marcus INEL 208) 526 9488 Piplica. Eugene J.
Wstinghouse 412 374 5310 Rettig, Walt INEL 208 526 0351 Schrock, Virgil UCB/ACRS Consultant 510 642 6431 Schultz, Richard INEL 208 526 9508 Sheldon, Rex 00E ID (20fs 526 5201 Sheron, Brian W.
NRC/RES 0 01 492 3500 Shotkin, Louis NRC/NES (301 492 3530 Sloan, Sandra H.
INEL (208 526-2796 Yedidia, Joe EPRI (415) 812 2825 Yonomoto, T.
JAERI 292 82 5320 Zuber, Novau AC5/ Consultant (301) 424 3585 i
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854 LEVELS OF ROSA-IV MODIFICATIONS EXAMINED IN THE COMPARISON
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HRSTI FVEL:
THE BASIC SET OF MODIHCATIONS:
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CMT PBLs (Proposed by mere inspection of the
REDUCED LOOP SEAL i'
ADDITIONAL BASIC MODIFICATION UPPER HEAD FLOWPATH (As a result of tie analyses)
ACCUMULATOR STAND PIPE TO GET RIGHT VOLUME.
y SECOND LEVEL PRESSURIZER AND SURGE LINE 1
PROPERLY SCALED HOT LEG THIRD LEVEL e
'IWO CMTS, SPLTT COLD LEG l
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CONCLUSIONS l
O AP600 UNIQUE SAFETh FEATURES BEHAVIOR IS BEYOND THE ASSESSED RANGE OF APPLICABILITY OF RELAP5. THE COMPLEX NATURE OF AP600 COMPONENT INTERACTIONS REQUIRES INTEGRAL TESTING FOR CODE ASSESSMENT.
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A MODIFIED ROSA, TO THE FIRST LEVEL.OF MODIFICATIONS (INCLUDING CHANGES IN THE UPPER hec D AND,THE i
ACCUMULATOR VOLUME). CAN CAPTURE MANY OF THE
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PHENOMENA EXPECTED 3 AP600 TRANSIENTS. IT WOULD BE REPRESENTATIVE OF THE 3-IN COLD LEG BREAK. IT WILL EXHIBIT THE PHENOMENA OF THE OTHER SYMMETRIC TRANSIENTS, ALTHOUGH MAGNITUDES AND TIMING MAY BE DIFFERENT.
O THE SECOND LEVEL OF MODIFICATIONS WILL ENHANCE ROSA'S ABILITY TO SIMULATE AP600 TRANSIENTS. IT EXPANDS ROSA'S ABILITY TO SIMUL / TE AP600 INVENTORY DISTRIBUTION DURING THE SLOWER TRANSIENTS (1-IN COLD LEG BREAK,1 TUBE SGTR, AND MSLB).
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[O THE THIRD LEVEL OF MODIFICATIONS, AS DEFINED, FAILS TO 7
CAPTURE THE NON-SYMMETRIC TRANSIENT (PBL BREAK) FOR i ;
WHICH IT WAS INTENDED. THE SPLIT COLD LEG CONFIGURATION INTRODUCES BEHAVIOR INTO THE
SIMULATION THAT IS NOT EXPECTED OF AP600. FURTHER
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MODIFICATIONS ARE REQUIRED TO ENABLE ROSA TO 2,
SIMULATE THE NON-SYMMETRIC BEHAVIOR OF AP600.
O A PBi_ BREAK IN ROSA, WITH FIRST AND SECOND LEVEL MODIFICATIONS, ALTHOUGH LACKING NON-SYMMETRIES j;
AND CMTS INTERACTIONS, CAN STILL PROVIDE DATA OF VALUE FOR CODE ASSESSMENT.
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- e as June 3,1992 MCO-24
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5 Recommendations for ROSA-IV i:
Hardware Modifications g
s e Based on performed analyses we recommend the
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i Level 1 modifications as providing the most effective means for code assessment
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e Considering the inherent limitations of scaled facilities and not complete representation of AP600 configuration, ROSA-IV with the first level of j
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modifications can provide reasonable simulation
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of most key phenomena expected during the selected AP600 transients
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- n Recommendations for ROSA-IV ij Hardware Modifications (cont'd) ij e Based on the analyses and new information about the ROSA-IV facility design we re>
- .ammend the
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following additional modifications i
- Vessel upper head flow paths to better represent AP600 2
- Corrected accumulator volumes jt:
- Second CMT
- Second DVI line i
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- Completely removed loop seal
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- DVI deflectors
- IRWST injection
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f Recommendations for ROSA-IV Hardware Modifications (cont'd) e Summary of proposed modifications
- Two CMTs with pressurizer and cold leg pressure balancing lines
- Two DVI lines and deflectors
- Four stages of ADS
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- Removed loop seal
- Upper head flow paths
- Accumulator volumes
- IRWST injections
- surge line and connections
- Pressurizer and surge line Ap Adct
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