ML20002D907
| ML20002D907 | |
| Person / Time | |
|---|---|
| Issue date: | 07/17/1980 |
| From: | Plesset M Advisory Committee on Reactor Safeguards |
| To: | Ahearne J NRC COMMISSION (OCM) |
| Shared Package | |
| ML19341B548 | List: |
| References | |
| REF-10CFR9.7 NUDOCS 8101230371 | |
| Download: ML20002D907 (10) | |
Text
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O ENCLOSURE 1 n aeog'o a
UNITED STATES
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E NUCLEAR REGULATORY COMMISSION g
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..r ADVlsORY COMMITTEE ON REACTOR SAFEGUARDS 0,
g WASHINGTON, D. C. 20555 1
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July 17, 19d0 Honorable John F Ahearna Chai rman U.S. Nuclear Regulatory Commission Washington, DC 20555
Dear Dr. Ahearne:
The Advisory Committee on Reactor Safeguards submits herewith its comments on the budget for FY 1982 of the Office of Nuclear Regulatory Research.
Only that portion of the budget relating to Program Support has been con-sidered.
The funding levels considered are those allocated by the EDO Staff in its preliminary markup of 2 July 1980 and those requested by RES in its reclama of 9 July 1980.
Comments on personnel requirements and allocations are included in a few instances where particularly appropriate.
Sincerely, Milton S. Plesset Chairman
Attachment:
NUREG-0699 81012 3 03Yf
ENCLOSURE 1 (continued) 2.
LOFT 2.1 Introduction The LOFT facility is the only integral f acility which models a PWR.
The shortcomings of the facility are well known and relate for the most part to deficiencies in vertical dimensions.
The nuclear core is slightly less than half the height of a PWR core.
This reduced height introduces some uncertainty in translating the early quench observed in the large LOCA test in LOFT to a full-size system.
Further, the height relation-ship between the core and the steam generators affects the interpretation of measurements of natural circulation heat transfer.
2.2 The LOFT Test Program LOFT tests were for some time directed toward a design basis accident involving the instantaneous double-ended cold leg break (DECLB).
Tests of this type have contributed to the unoerstanding of this kind of acci-dent and also have contributed. to code assessment.
In response to a strongly modified view of more immediate needs, the LOFT program was redirected in FY 1980 to the study of reactor transients which were the result of small breaks.
The current plans call for further tests of this kind in FY 1981.
Both the FY 1980 and the FY 1981 programs as now planned include other types of t ransients, including, particularly in FY 1981 tests concerned with anticipated transients without scram.
The signifi-cant test proposed for FY 1982 is a DECLB at the higher core power of 16 kw/ft.
No further small break tests are scheduled for FY 1982.
A test has been proposed for FY 1983 with pressurized fuel.
Although we believe that LOFT will essentially complete its NRC mission in FY 1982 with NRC funding phased out at the end of FY 1982, the LOFT System could still be a valuable tool for the nuclear power indust ry.
The LOFT installation could be offered to the nuclear industry to be operated with industry financial support as a facility wnich would en-hance operational capabilities of the nuclear industry.
2.3 Recommendations LOFT represents the largest single expenditure in the safety research budget so that its program must be considered with special care.
We recommend that the tests through FY 1982 be adequately funded and that following the 1982 tests the facility be decommissioned unless it is taken over by the nuclear industry.
The final tests to be run to the completion of the program should be carefully scrutinized and evaluated by RES to obtain the most useful final series.
We would also wish to contribute to the choice of these tests.
Efficient operation of the facility appears to require the requested level of support and therefore we endorse that level.
19
ENCLOSURE 2 MEMBERS AND CONSULTANTS OF TNE i
LOFT SPECIAL REVIEW GROUP MEMBERS AFFILIATION D. Ross (Chairman)
Office of Nuclear Reactor Regulation, NRC B. Sheron Office of Nuclear Reactor Regulation, NRC R. Bernero Office of Nuclear Regulatory Research, NRC R. Woodruff Office of Inspection & Enforcement, NRC R. Capra Office of Nuclear Reactor Regulation, NRC L. Jaffee National Aeronautics & Space Administration A. Pressesky Department of Energy CONSULTANTS H. Kouts Brookhaven Nations 1 Laboratory A. William Snyder Sandia Laboratories H. Isbin University of Minnesota R. Pack Institute of Nuclear Power Operations B. Sun Electric Power Research Institute F. Finlayson Aerospace Corporation P. Griffith Massachusetts Institute of Technology I. Catton University of California at Los Angeles /
ACRS Consultant I
1
ENCLOSURE 3 CHARTER OF THE LOFT SPECIAL REVIEW GROUP "This group is established for the purpose of reviewing the LOFT program and reporting on their findings to the NRC Commissioners.
The review shall be technical in nature, focusing on, but not limited to, the benefits expected from the program planned for the FY 1981 to FY 1983 period.
The primary purpose of the group is to consider whether LOFT should be decommis-sioned in FY 1983, as recommended by the ACRS.
The group would be expected to consider the LOFT progiam from the perspective of NRC's overall research program and in terms of the needs of reactor regulation.
To facilitate this work, NRC and the INEL, where LOFT is located, would provide presentations, reports, and tours and interviews.
Also, the group would be welcome to attend any tests performed in the LOFT reactor or related facilities.
The report would be intended to aid the Commissioners in their decision whether to continue NRC support of the LOFT project beyond FY 1982. The report should address specific regulatory needs and describe how the results of the LOFT pro-gram are expected to meet those needs.
Furthermore, based on the performance and responsiveness of the program to date, the report should indicate the likeli-hood that the planned program will provide the expected information and that it maintains reasonable flexibility to address changing regulatory issues.
A final report would be issued by February 3, 1981 and after follow-up discus-sions with the Commissioners, the group would be dissolved."
ENCLOSURE 4 PLANNED LOFT TEST SEQUENCE FOR DIFFERENT OPTIONS OPTION A: Run through FY-1982/Decomission FY-1983 OPTION B: Run through FY-1983/Decomission FY-1984 OPTION C: Run through FY-1985/Decomission FY-1986 The attached sheets show the planned tests and sequence should either Option A, B or C be selected by the Comission.
4
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SEPT 83 BEGIN CEANtP, POST-IRPADIATIG1 EXNTIATION #0 FINAL #!ALYSES, ECGHISSIGl #:D DISo0SE OF PIL DUPJilG P/19PA, 2
PLANNED LOFT TEST SEQUENCE
-0PTION C **
AND TARGET DATES
- AS OF SEPTEMBER 1980 i
SPECI AL LOFT REVIEW GROUP OPTIONS A & B INDICATED AS "A" AND "B"
- for each year, consnittment dates are roughly 2 inonths later INITIAL INITIAL TEST TARGET POWER CORE ID DATE LEVEL (MW)
AT *F COP 91ENTS L3-6 12-1-80 50 35 Small break (2.5%) intact loop cold leg --- pumps on.
Pumps tripped at end of experiment to measure water remaining.
L8-1 12-1-80 Add on to L3-6 Core uncovery without ECC at low decay heat level.
L9-1 3-4-81 50 35 Loss of all feedwater (multiple failures) with scram on high pressure; PPS setpoints representative of LPWR (PORV challenged.) tilld ATWS.
L3-3 4-8-81 6 "* 50 35 Small cold leg break (0.16%) HPIS flow approximately I
equal to break flow.
Dry steam generator secondary.
4 Determine the boundary between break heat removal and PORV heat removal. Needs further justification.
CV leak 6/81 Required test of containment leak integrity.
Test L6-7 7/81 50 65 LOFT typicality to Arkansas Nuclear One startup test.
L9-2 7/81 Add on to L6-7 Rapid cold water accident, upper plenum voiding.
LS-1 8/81 50 65 Intermediate size break (accunnlator line).
Determine if large break and small break nodels continue to predict intennediate break results. Also check out liquid level device.
L8-2 8/81 Add on to L5-1 Core uncovery at high decay heat level.
Reflood with degraded ECC capability. May be the same as LS-1.
- -NOTE: Option C includes all items listed, including those under Option A and B 4
PLANNED LOFT TEST SEQUENCE AND TARGET DATES AS OF SEPTEMBER 1980 (continued) 5 INITIAL INITIAL TEST TARGET POWER CORE 10 DATE LEVEL (MW)
AT "F COMMENTS Whole core 10/81 F1 center bundle at 350 psi (BOL). Large peaking Changeout factor if only CB changed.
L2-5 1/82 B
16 kw/ f t 65 Worst prototypic hydraulic conditions in core.
Investigate fuel behavior at BOL fuel pressure (no fuel damage expected).
Replaces CB 3/82 F2 will be pressurized to 700 psi.
F1 with F2 L2-6 5/82 A,B 16 kw/ft 65 Same as L2-5 with 700 psi fuel pressure (EOL). Fuel damage and fission product release expected.
Replaces :2 7/82 Only minimal fuel damage experiments can be done until with unpress F1 is examined for damages.
Al LS-2 9/82 13 16 kw/ft 65 Intermediate size break on hot leg.
Pressurizer surge line.
fleeds further justification based on LS-1.
L6-4 9/82 B
16 kw/ft 65 Uncontrolled rod withdrawal at power.
Investigate worst case moderate frequency accident.
L9-3 12/82 A,B 16 kw/ft 65 ATWS. Loss-of-Feedwater is initiating event.
(Multiple failures.)
L9-4 3/83 B
16 kw/ft 65 ATWS.
Loss of offsite power is initiating event.
(Multiple failures.)
Put Fl Bundle F1 inspection completed and fuel is assumed not damaged.
back in L8-3 8/83 16 kw/ft 65 Small break with slow core heat up (l'F/ min). Uniform clad swelling and blockage of flow channel.
Investigate potential initiating events.
(Candidate: Loss-of-Feedwater.)
Replace F1 with A3
PLANNED LOFT TEST SEQUENCE AND TARGET DATES AS OF SEPTEMBER 1980 (Ccntinued) 1 INITIAL INITIAL TEST TARGET POWER CORE ID DATE LEVEL (MW)
AT *F COMENTS L7-1 12/83 B
16 kw/ft 65 Large break with S.G. tube ruptures at start of reflood/ refill (>25 tubes ruptures). Provides upper bound of envelope on effect of ruptures). Critical number of tube ruptures resulting in extreme core temperatures expected to be between 10 and 25 based on Semiscale results.
L7-2 2/84 16 kw/ f t 65 Large break with S.G. tube ruptures at start of reflood/
refill (<10 tubes ruptu: < d).
Provides a lower bound of envelope on effect of ruptures. L7-3 should be inserted if possible which has critical number of ruptures.
L4-1 5/84 16 kw/ft 65 200% cold leg break. Accumulator injection into U.P.
Investigate topdown core quench. Applicability to Ulli plants.
L4-2 8/84 16 kw/ft 65 200% cold leg break.
U.P. LPIS injection.
Investigate W two loop plant phenomena.
Replace A3 12/d4 with press F3 L8-4 3/85 A,B 16 kw/ft 65 Severe core damage.
Investigate potential initiating events.
(Candidate: Loss of offsite power.)
Whole core-4/85 F4 Center bundle.
changeout L10-1 7/85 16 kw/ft 65 Override test. Override of L8-3 transient.
L10-2 9/85 16 kw/ft 65 Override test. Override of L8-4 transient.
L8-5 11/85 16 kw/ft 65 Severe core damage.
Investigate potential initiating events (Candidate: Steam line rupture).
Deconnission 12/86
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