ML19345B566
| ML19345B566 | |
| Person / Time | |
|---|---|
| Issue date: | 10/10/1980 |
| From: | Advisory Committee on Reactor Safeguards |
| To: | Advisory Committee on Reactor Safeguards |
| References | |
| ACRS-1776, NUDOCS 8012020072 | |
| Download: ML19345B566 (7) | |
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/7g ACRS REACTOR FUEL SUBCOMMITTEE MEETING MINIRES AUGUST 21, 1980 IDAHO FALLS, ID On August 21, 1980 the ACRS Reactor Fuel Subcomittee held a meeting in Idaho Falls', Idaho. The purpose of the meeting was to obtain infonnation on the NRC Fuel Behavior Research Branch (FBRB) in-pile test Programs at the PBF, NRU, and ESSOR facilities for the Committee's annual Reports te the Comission and Congress.
Principle attendees of the meeting are noted below:
ACRS NRC EG&G P. Shewman M. Picklesimer, RES P. MacDonald W. Mathis R. VanHouten, RES B. Buescher D. Okrent W. Johnston, NRR D. Osetek A. Solomon, Consultant M. Tokar, NRR A complete list of attendees is attached to the office copy of these minutes.
OVERVIEW OF THE FUEL BEHAVIOR RESEARCH BRANCH IN-PILE RESEARCH PROGRAMS -
M. PICKESIMER - FBRB Dr. M. Picklesimer presented an overview of the PBF test program. He noted that the original "40-test series" will be completed by next spring with the running of two LOCA tests. With the completion of the "40-test series", a new PBF test program will begin consisting of severe fuel damage (SFD) and operational transient (0PTRAN) tests. Dr. Picklesimer also noted that the severe core damage program (which includes PBF) will comprise 70% of the FBRB budget by 1984.
Dr. Okrent asked if the SFD program is being closely coordinated with other programs addressing core melt research. Dr. Picklesimer replied that the SFD work is coordinated with similar work underway both in the US and overseas.
Dr. Okrent recomended that NRC hire outside consultants to advise the Research Review Groups that oversee the SFD program and other research pro-grams. Dr. Shewmon agreed with this recomendation and suggested that this topic should be taken up by the full Comittee to detennine if the ACRS should make a recomendation in this area.
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August 21, 1980 Dr. Okrent also requested that for each research program discussed at the meeting, RES state specifically what information was sought and how the given program was expected to provide the desired data.
NRR USER'S SEED FOR IN-PILE TEST DATA - W. JOHNSTON, M. TOKAR - CORE PERFORMANCE BRANCH I
Drs. W. Johnston and M. Tokar discussed the NRC NRR User's need for in-pile research data. Dr. Johnston reviewed items labelled " upcoming licensing decisions" for the Core Performance Branch.
Items cited included extended burnup limits, clad rupture ballooning and blockage, and estimation of fuel damage in excess of design _ bases. In-pile programs at PBF, Halden, NRU, ESSOR, and Studsvik were cited as expecting to provide information to address the above items.
Dr. Tokar discussed the use of PBF test results for addressing licensing needs. He noted that two years ago the PBF RIA experiments were top priority due to identified deficiencies in licensing position. This concern has now abated with the receipt of Brookhaven' calculations showing that the 280 cal /gr.
fuel failure limit ~ will 'not be approached in a power reactor. The OPTRAN tests are expected to address the CPB concern with the pellet-cladding interaction (PCI) cladding failure mechanism.
Dr. Okrent questioned the need for PBF tests to address the PCI failure mechanism,especiallysincethePCIfailurerateissolow. He questioned whether NRC should establish an upper limit on fuel rod failure,'belcw which the Staff would accept any failures as inevitable. Dr. Tokar agreed' with this approach in principal, and he said he is attempting to draft a position on this item. Dr. Shewmon requested a copy of this position paper when it is available.
Dr. Tokar also noted that the Core Performance Branch is exploring the idea of requiring Licensees to insert a small amount of segmented test rods with.each reactor reload in order to build up an inventory of high-burnup test rods to be used in test reactor experiments. He requested Subconnittee comment on this proposal.
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August 21,1980
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PBF - 198D TEST StNMARY AND FUTURE TEST PLANS - P. MACDONALD - EG&G -
Mr. P. MacDonald (EG&G). detailed the results of the PCM, LOCA, and RIA tests in PBF and described the planned OPTRAN and SCD tests.
He noted that the PCM tests demonstrated that the concerns over rod failure from film boiling and DNB propagation appear to be unjustified. Also, no energetic fuel-coolant interactions were seen in any of the PCM tests. The key result from the RIA tests is that the mede and consequences of red failure are significantly affected by prior irradiation.
During discussion of the OPTRAN test program, Dr. Okrent questioned the usefulness of such tests as simulating a BWR turbine trip with bypass when this event occurs relatively frequently in power reactors.
At the behest. of Dr. Okrent, the Subcommittee requested that, by the end of the year, NRC provide a document detailing the justification for each in-pile-test program proposed by FBRS.
Dr. Shemwon in turn cited an EPRI
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report ("A Peview of the PBF Program as a Source of Data for Qualification for Fuel Behavior Codes" - EPRI NP-1202), that he felt contained a good example of a reasonably concise overview of a particular research program.
He urged NRC Research to attempt to develop a set of criteria for justifying the in-pile programs discussed at the meeting.
SEVERE CORE DAMAGE PROGRAM OVERVIEW - M. PICXLESIMER - FBRB Dr. Picklesimer presented an overview of the new FBRB Severe Core Damage (SCD) Program. The Program is still in the formulative stages and is being coordinated with C. Kelber's Severe Accident Phenomena and Mitigation program element in RSR. Study needs are under discussion with the technical comunity.
Future meetings are scheduled for October 1980 (during the NRC Water Reactor Safety Research Meeting to be held in October), and an Ad-Hoc Experimenter's Meeting is planned for November or December 1980.
Dr. Picklesimer also noted that SCD Program data is expected from PBF during FY-82-85, from TMI-2 in FY-83-84, from LOFT (if the tests are run) about FY-65, and from ESSOR from FY-84-86.
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August 21, 1980 Reactor Fuel Meet..3 Dr. Okrent said that the SCD Program experiments should be scoped to answer the questions of how this work will impact present and future plant design, and how it would influence NRC policy decisions and NRC actions during any future severe accidents.
SEVERE FUEL DAMAGE TESTS IN PBF - B. BUESCHER - EG&G Mr. B., Buescher (EG&G) discussed the planned PBF Severe Fuel Damage (SFD) test series. These tests are designed to address Class 9 issues involing core coolability. The planned' set of Phase I tests will reach temperatures of m3680 F (2300"K), and result in debris bed formations. A 32-rod bundle will be used in these tests. The first test is scheduled for late 1981.
In response to a question from Dr. Okrent, Mr. Buescher said the SFD test objective is to attempt to define core coolability beyond the WASH-1400 0
assumed 2200 F limit. Dr. Okrent questioned the usefulness of this Program; however, Dr. Shewmon said he felt there was some merit in exploring core
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0 coolability beyond the WASH-1400 assumption of core melt at 2200 F.
ESSOR-SUPER SARA TEST PROGRAM AND SCHEDULE - R. VANHOUTEN - FBRB Dr. R. VanHouten described the ESSOR Super Sara Severe Core Damage (SCD) s test Program. There are 18 SCD tests scheduled between 1983-86. Twelve of these tests will be TMI-2 small break LOCA tests. The NRC cost is
- $11M out of a total Program cost of $140M.
Dr. VanHouten noted that there is significant parallel between the ESSOR and P3F-SCD tests, and considerable constructive exchange has occurred in the areas of instrumentation and experimental design. With ESSOR, as in PBF, some of tests will go to rubble bed fomation. Dr. VanHouten also indicated that ESSOR test data would be helpful for the expected NRC rulemaking addressing Class 9 accidents.
Dr. Shewmon requested that NRC Research provide a detailed budget breakdown of the in-pile test Programs for use in developing the ACRS Report to Congress on the FY-1982 Research Budget. He noted that the Committee would need this information around November-December of this year.
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9o August 21, 1980 Reactor Fuel Meet t
During discussion of the ESSOR Program Dr. Okrent, citing the recent Browns Ferry partial failure to scram event, speculated whether this type of event calls into question the proper orientation of the entire NRC Research Program..
I NRU LOCA TEST PROGRAM AND SCHEDULE - R. VANHOUTEN The NRU LOCA Test Program was reviewed by Dr. VanHouten. The Program's objective is to develop a well-characterized data set for full-length multi-rod (6x6 w/o corner rods) bundles under LOCA heatup and reflood conditions. The first set of 18 thennal-hydraulics tests are scheduled to begin in October 1980. A set of 5 materials tests (cladding swell and rupture) are scheduled to begin in February 1981. The materials tests are expected to evaluate a number of parameters specified in 10 CFR 50.46 and Appendix K.
Dr. Okrent asked if the NRU reflood rate can be set at less than one inch /second.
Battelle PNL replied that this is very difficult given the experimental set-up.
[ Note: A recent memo from NRC Research indicates that an evaluation has been performed by the NRU experimentalists to show that reflood rates can be lowered to about 0.5 inches /second.
It now appears that some of the reflood tests.
will be run at rates below 1 inch /second.]
PBF FISSION PRODUCT DETECTION SYSTEM - D. OSETEK - EG&G The fission product (FP) detection system in use on PBF was described by Mr. Osetek. The system is used to provide test support to PBF and document FP behavior as well as build a data base in an attempt to estimate accident consequence estimates. Mr. Osetak also said a FP detection system similar to the one at PBF may be useful as a," fuel condition monitor" that,could Dr. Okrent provide on-line monitoring of fuel behavior at a power reactor.
observed that one must first evaluate the effects of the test flow loop to assute the generic usefulness of such a system.
SUBCOR4ITTEE DISCUSSION Dr. Shewman reviewed the requests for information made on behalf of the Subconsnittee or individual, members of the Subcomittee.
Items mentioned 1
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- b Reactor Fuel Meeting August 21, 1980
.9 by Dr. Shewmon included a detailed budget breakdown of the RES 'in-pile programs, the request by Dr. Okrent for specific NRC statements on the need for each in-pile experiment and what NRC expects to learn from j
these experiments, and finally the Subcommittee would like to see the results of NRR's attempt to define a fuel rod failure threshold criteria I
which would in effect ignore fuel rod failures below a certain percentage
'(e.g.
0.01 - 0.001%).
Note: Additional details of this meeting can be obtained from a transcript located in the NRC Public Document Room,1717 H
%rrept. N.W.. Washinaton, D.C.
A transcript can also be obtained, at cost, from Alder:on Reporting Company, Inc.,
400 Virginia Avenue, S.W., Washington, D.C. 20024, (202) 554-2345.
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- LIST OF DOCtMENTS MADE AVAILABLE AT AUGUST 21f 1980 SUBCOMITTEE MEETING 1.
Vu-Graphs:
NRU - 90 EG&G - 53
- 2. -Reports:
"LOCA Simulation in the NRC Reactor - Pacific Northwest Laboratory",
C. L. Mohr PNL and R. Van Houten, U.S. NRC.
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