ML20085F601
| ML20085F601 | |
| Person / Time | |
|---|---|
| Site: | Saxton File:GPU Nuclear icon.png |
| Issue date: | 03/04/1968 |
| From: | Neidig R SAXTON NUCLEAR EXPERIMENTAL CORP. |
| To: | |
| Shared Package | |
| ML20083L048 | List:
|
| References | |
| FOIA-91-17 NUDOCS 9110220241 | |
| Download: ML20085F601 (5) | |
Text
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SAXTJN NUCL: At E.{P.0lIl07h'al C0HPJHATION DOCl'i:T :.'O.
50 146 LICL.hE UPd-4 CHANGE RE2UEST NO. 31 1,
Applicant hereby submits Change Request No. 31 in compliance with paragraph 3B of licence DPR-4 for change of the Technical Specifications to be authorized by the Commission as provided in 10 CFR 50.59 SAlTON NUCLEAR EXPERIl! ENTAL CORPORATION By
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P. L. Heidig President
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9110220241 910424 POR FOIA DEKOK91-17 PDR 77c
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Docket No. 50-146 DP!(-4 Technical Specifications i
Change No. 31
, Page 1 of 2 Pages
- 1b 1.
Descrintion of Chance In Supplenent !;c. 1 to the Technical Specifications, add the following Test Fuel Assembly to Item F.2.
Test Fuel Assembly XXIII One 4 rod fully canned 2x2 subassembly containing:
1.
Two removable rods clad with Zircaloy-4 having a nominal thickness of 23 5 mils containing Pu0 UO2 pellets uniformly enriched to 2
6.6 w/o Puo,, and previously irradiated to peak burnup of about 18,000MRD/flTMatpeaklinearpowerdensitiesupto16kw/ft.
These rods will occupy one diagonal of the subasseably.
2.
One dummy rod of the same size and configuration as a standard Saxton fuel rod but containing no fuel.
This rod is orificed near the top and bottom end plugs to permit filling of the rod internal volume with primary coolant.
3 One instrument tube containing several thermocouples, a pitot tube, and a miniature ionization chamber.
The fully canned (no perforations in the enclosure walls) test subascembly will be located in the central core position (N-1) and is designed to operate at a maximum linear power density of 25 kw/f t.
2.
Purpose of Change The purpose of this change is to demonstrate the capability of prototypical fuel rods to operate at an actual peak linear Zircaloy-L clad Pu0 UO2 2
power density of 21.5 kw/ft. A design value of 25 kw/ft results in a 95%
confidence level that these rods will operate at 21 5 kw/ft.
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Docket No. 50-146 DPR-4 Technical Specifications Change Request No. 31 Page 2 of 2 Pages I
3 Safet; Considerations These test rods are standard Saxton Plutonium fuel rods which have previously ' cen irradiated in Saxton, Due to tne increased pitch in the o
2x2 subassembly these rods will lead the core, thus operating at a higher linear heat rating while the renainder of the core does not exceed the 35 Mit license linit of 191 ka</f t.
Although operating at high power densities, the subassembly has acceptable DNB ratios for steady state and 114% overpower conditions.
The subassembly instrumentation will provide measurenents of the actual operating conditions to assure that a linear power density of 25 kw/ft will not be exceeded.
The data will allow correlation of the reactor power level with the maximun specific power of the subassembly.
A procedure will be available and followed for evaluating the performance of this subassembly during operation.
The principal thermal and hydraulic parameters calculated for these fuel rods at 35 MWt reactor operation are summarized in Table I.
Center melting will not occur at 25 kw/ft.
At 28.5 kw/ft, some center melting may occur.
Experimental data reported in the literature indicates that there are no serious safety problems involved in this mode of operation, since the solid portion of the fuel will keep any molten fuel away from the clad, preventing any interaction between the two (fuel rods operating with limited center melting was previously approved in Change No. 20).
4.
Health and Safety It is our opinion that the health and safety of the public will not be endangered by this change.
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- TABIE I 5 -- - -
s a-4 THERMin. !JD HYDRAULIC PARAMETtHS inlet (35Mv) = h80 F - nominal T
Max. Thermal Output
= 25.0 kv/ft 2
Max. Surface Heat Flux = 833,000 BTU /Hr. ft Hot Channel Factors:
Fq - based on core avera6e Kv/ft h.23 F6H - based on core average Kv/ft 2:98 Minimum DNB ratios by W-3 correlation 2.62 100% Power 2200 psia
=
2.13 lik% Power 2050 psia
=
i Average clad temperature 100% Power Th3 F (Nominal) 11L% Power Th6 F (Nominal)
Clad stresses nominal 20,000 psi j
gcr.at case' 60,000 psi Clad strain nominal
-0.26%, range 0.58%
vorst case" 0.6 %, range 1%
Fuel Center Terperature 25 kv/ft M16,F 28.5 kv/ft h965 F Loss-of-Flow Accident (extended coastdown)
Initial Conditions Power 1.ogx35MWth Inlet temperature 485 F Primary Pressure 2150 psia Minimum DNBR 1.67 Maximum I.D. Clad Temperature 835 F
- Minimum Gap - Maximum Fuel Density
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- 3 The difficulty experienced with this rod was reviewed by the Saxton It was concluded that On-Sita Safety Ccnmittee and by the reactor manufacturer.
'probably a small piece of foreign material was lodged in the control rod drive mechania dashpot and that it was subsequently removed by the self-fluohing action of the dashpot during the rod drops.
Sincerely, fb r C. R. Montgomery General Manager cc:
G. F. Trowbridge, Esquiro O
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