ML20028G133
| ML20028G133 | |
| Person / Time | |
|---|---|
| Site: | Clinch River |
| Issue date: | 02/04/1983 |
| From: | Longenecker J ENERGY, DEPT. OF, CLINCH RIVER BREEDER REACTOR PLANT |
| To: | Grace J Office of Nuclear Reactor Regulation |
| References | |
| HQ:S:83:210, NUDOCS 8302070440 | |
| Download: ML20028G133 (3) | |
Text
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0() -S.3 7 Department of Energy Washington, D.C. 20545 Docket No. 50-537 IlQ:S:83:210 FEB 01 1983 Dr. J. Nelson Grace, Director CRBR Program Of fice Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission i
l Washington, D.C.
20555
Dear Dr. Grace:
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INFORMATION ON PRECAUTIONS TilAT PRECLUDE ASSEMBLY BLOCKAGES - CLINCll RIVER BREEDER REACTOR PLANT Enclosed is information requested by the Nuclear Regulatory Commission staff on fuel blanket, and removable radial shield assembly precautions 2
that preclude assembly blockages.
This information will be included in the next Preliminary Safety Analysis Report amendment.
If you have any questions, please call Wayne Pasko (FTS 626-6096) of the Project Office Oak Ridge staff.
Sincerely,
(
John R. Longenecker N-(
Acting Director, Office of Breeder Demonstration Projects Office of Nuclear Energy Enclosure cc: Service List Standard Distribution Licensing Distribution hO 8302070440 830204 PDR ADOCK 05000537 A
i ENCLOSURE The detailed formulation of the design criteria of Table 4.2-7 and the conditions for which they are applicable, are given in the CRBRP fuel assembly stress report, Reference 171.
4.2.1.1.2.3 Requirements for Design Features in addition to the preceding operational requirements, specific design features shall be incorporated into the fuel and blanket assembly designs to preclude the accident conditions discussed in Chapter 15.4 and any detrimental effects which could adversely affect the attainable design life.
1.
Sufficient constraint shall be applied to the fuel and blanket rods-to minimize fretting and wear at the support points.
2.
The fuel and blanket assembly materials shall be compatible with ad-joining materials and environmental conditions during their design lifetime. Where potential for excessive galling or self-welding exists, mating components shall be hard coated.
3.'
The relative location of the pellet column within the fuel and blanket rods shall be maintained during shipping to prevent damaging reactivity fluctuations during start-up by utilizing a properly designed axial spring support system.
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4.
The assembly axial support system shall maintain fuel and blanket assembly axial positions under all steady state and transient operating con-ditions, while providing for differential thermal expansion of the internalstructuresandtheirradiationinducedexpansionoftheassgmblies.
With the current CRBR baseline design, the limit is 2.5 inches at 70 f.
5.
The inlet nozzles for the assemblies, in conjunction with the reactor internals, shall be designed with sufficient aperture redundancy to preclude total inlet blockage and to provide for adequate cooling even Led //,,
af ter total blockage of one inlet passage.
To prevent loading of a fuel or blanket assembly into a position where 7.
it is undercooled, the following situations must be prevented by a properly designed discrimination system.
a.
Fuel assembly insertion into a position which it would be under-cooled, i.e., a position in which more coolant flow through the assembly is required for heat removal than can be admitted by the flow orifice in that assembly or receptacle.
b.
Fuel assembly insertion into positions in the core that are pro-vided for the control rod assemblies, blanket assemblies and re-movable shield assemblies, except for those positions where fuel 51 and inner blanket assemblies are intentionally interchangeable.
Amend. 51 4.2-17 Sept. 1979
i INSERT "A" E Adequate precautions are taken via project procedures to preclude fuel, blanket and removable radial shield assembly (RRSA) blockages after assembly at the fabricator and prior to reactor insertion.
These precautions include 1) an air flow test at the f abricator af ter component assembly, 2) controlled storage and shipment to the CRBRP site, and 3) visual inspection of inlet nozzles upon assembly receipt at the CRBRP site.
These precautions preclude the necessity for evaluations of blocked assemblies during and after refueling.
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