ML20195J557
| ML20195J557 | |
| Person / Time | |
|---|---|
| Site: | 07000036 |
| Issue date: | 06/16/1988 |
| From: | Rouse L NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| To: | |
| Shared Package | |
| ML20195J478 | List: |
| References | |
| NUDOCS 8806290153 | |
| Download: ML20195J557 (5) | |
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JUN 161988 IMUF:GHB DOCKET NO: 70-36 LICENSEE: Combustion Engineering, Inc. (CE)
Hematite, Missouri
SUBJECT:
SAFETY EVALUATION REPORT, REVISED LICENSE AMENDMENT APPLICATION DATED APRIL 29, 1988, AND SUPPLEMENT DATED JUNE 6, 1988, RE PROCESSING URANIUM CONTAINING UP TO 5 WEIGHT PERCENT U-235
Background
CE is currently licensed to possess and use uranium enriched up to 4.1 w/o U-235.
On December 28, 1987, CE submitted an application to increase the U-235 enrichment to 5 w/o. Following a site visit and discussions on April 14-15, 1988, by the reviewer, CE submitted the revised application. The submittal includes proposed new license conditions (Part I) and a revised safety demonstration (Part II). A supplement, dated June 6, 1986, was submitted following additional discussions by telephone.
Discussion CE has revised Part I of the application to change the maximum U-235 enrichment to 5 w/o and to revise certain technical requirements for nuclear criticality safety. For individual units which are spaced by the surface density method, CE has dual criteria, viz., a specified safety factor for optimumly moderated and fully reflected units and a maximum fraction of the optimumly moderated but unreflected spherical unit. CE has extended Table 4.2.4 to provide allowable sizes for units enriched up to 5 w/o U-235. This approach is acceptable, but it must be emphasized that the dual limits in Sections 4.2.3 and 4.2.5 must be satisfied.
In Section 4.2.3, CE has revised the k-effective limit for single units and for an array of units. CE proposed a k effective limit of <0.95 for all
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activities except for the UF -U0,6 conversion process in the oxide plant.
Because CE did not propose a k-effective limit for the oxide plant, the staff recommends the following license condition:
Notwithstanding the statement in Section 4.2.3 of the application, the k-effective of a unit or an array of units shall not exceed 0.95 unless specifically authorized by the license.
The licensee modified the section of the license containing assumptions and criteria for establishing safe individual units and arrays. Proposed criteria e806290153 880616 PDR ADOCK 07000036 C PDH
2 JUN 161993 were provided for moderation control units and for units with optimum moderation and full reflection. This has the potential for confusion in the safe application of criteria. To assure nuclear criticality safety, the staff recommends the following license condition:
Nuclear criticality safety evaluations performed by the licensee in accordance with Section 2.7, Part I of the application, shall be based on assumptions of optimum moderation and reflection of individual safe units and of arrays.
The staff notes that the license does not require an independent review of k-effective calculations by a qualified nuclear criticality specialist. To correct this oversight, the staff recommends the following license condition:
Nuclear criticality safety evaluations involvinq k-effective calculations performed by a Nuclear Criticality Specialist snall be independently reviewed and approved by an individual having, as a minimum, the qualifications of a Nuclear Criticality Specialist.
It should be noted that CE's practice has been consistent with this proposed license condition. The condition provides reasonable assurance that the practice will be continued.
The licensee failed to recognize that Section 8.1, Part II of the applica:. ion, is based on uranium enriched to 4.1%. This problem was identified in the April 8, 1988 letter to the licensee and was discussed during the site visit on April 14-15. The licensee was notifiea of this error again by telephone on May 27, 1988 and submitted revised pages on June 6, 1988. The safety demonstration now reflects use of 5 w/o enriched uranium.
In Section 8.1.6, Part II of the application, the licensee described the powder packaging process. A 10-mil poly bag will be used inside a stainless steel (SS) container to package the UO7 powder for storage pending shipment. In this section, the licensee descrTbed the moisture content as "typically" <0.05 w/o water. At this water levci, the moderating effect of the poly bag will not be significant and will be offset by the poison effect of the SS container.
The licensee maintains an option to process the powder into pellets for shipment rather than shipping the powder. The first steps in the pelletizing operation are agglomeration, drying, and granulation. The powder and binder are agglomerated in a 25.7-liter blender. The material is dropped onto a drying belt, and then into a 15-liter granulator and collected in 11"x13" metal containers. The agglomerator volume exceeds the 22-liter volume specified in Table 4.2.4, Part I of the application. The license also assumed moderation control, but proposed unquantified limits for hydrogenous material in the agglomeration hood. In addition, the licensee failed to provide a spacing demonstration for the agglomeration and granulation process.
Agglomerated powder is stored on the mezanine above the mod; ration control storage conveyors. The k-effective for the array was calculated assuming a mass limit of 41 kg U0, and a water limit of 2 w/o. These assumptions are not justified in Part II nur limited by license conditions in Part I.
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4 JUN 161988 Pressing is done by attaching a 5 gallon pail of powder to a 29-liter hopper on the pellet press. Pel'iets are collected in sintering trays with a maximum volume of 4' liters. The hopper exceeds the allowable volume limit' for an SIC in Table 4.2.4.
The bases for nuclear criticality. safety for agglomeration, storage, and pelletizing processes have not been provided. To allow the licensee some capability to process the higher errichment, the staff propose the following license condition: '
For uranium enriched to more than 4.1 w/o U-235, the licensee shall limit the agglomeration / granulation process, each agglomerated powder st.) rage location, and the pellet pressing operation to safe mass units as specified in Table 4.2.4, Part I of the application.
The remainina operations of dewaxing, sintering, grinding, inspection, and packaging are done using the safe slab limit specified in Table 4.2.4, Part I.
The centrifuge operr. tion for grinder coolant is volume limited in accordance with ;
Table 4.2.4.
The licensee has revised the nuclear safety analyses for several pr^ cess steps in scrap recovery. In Section 8.7.3, Part II of the application, the li.:ensee could not justify the dissolver as a reflected infinite cylinder, so the safety factor for full reflection in the license was applied to the bare cylinder. The dissolver is neither infinitely long nor a bare cylinder. The lirensee also violated the spacing criteria. Had the licensee performed a buckling conversion on the dissulver dimensions and considered the dissolver to be nominally -
(partially) reflected, the safety demonstration would have been acceptable. The staff's analysis demonstrated safety of the dsssoher.
In Section 8.7.5, the licensee made similar errors in the application of his criteria. In addition, dimensions of the precipitator are based on U0 - H0 mixtures rather than the UNH - U03 mixtures. Useofdimensionsforso$utio$s would not have required the licendee to violate his criteria.
The licensee conservatively calculated k-effective for the precipitate dryer.
The notable conservative assumption was neglecting structural steel in the calculation. Including the steel in the system would have reduced the
. k-effective below 0.92. The license limit for k-effective is 0.95.
l In Chapter 9, Part II of the app'lication, the licenseo has revised the detailed analysis of the UF - 00 conversion process. The conversion process takes placeinthree10-Inchd$ameterreactors. Each reactor has .- 12-inch diameter disengaging column on top of the 10-inch process column. The licensee's analysis of a worst-case situation yielded a k-effective of 0.95 for the reactor and a k-effective of C.47 for the array. The worst case assumed that the entire ,
reactor was filled with U0 and moderated with condensed steam. There are a l numberofcontrolsandalahmswhichmakethisworst-casesituationvery conservative.
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h 4 JUN 161988 Loss of power to the reactor would result in termination of steam flow and automatic-purging by nitrogen. An alarm would sound upon-loss of furnace heating. If an operator did.not respond to the alarm and the steam condensed, high pressure' conditions would cause termination of steam flow. If all of these controls failed, more than 8' hours-of steam flow wculd be required to fill the 10-inch reactor with condensed steam. The reactor is unloaded at 2-hour intervals softhat the water would be discharged through the powder valve system. The licensee has proposed a license condition which would require calibration of the high pressure switches every six months. This calibration, combined with the failsafe alarm features of the temperature controllers,.
provides reasonable assuran'ce that the worst-case scenario is not feasible.
Accordingly the high k-effective values can be accepted by the staff.
Conclusion / Recommendation The staff concludes that the licensee can safely process uranium enriched to 5 w/o U-235. Subject to the above recommended license conditions, approval of the application is recommended.
The Region III Principal Inspector has no objection to this action.
0%,lsped ey:
George H. Bidinger Uranium Fuel Section l Fuel Cycle Safety Branch Division of Industrial and Medical Nuclear Safety, HMSS J1JN 161988 pung Jerry J. Swift, Section Leader
- Uranium Fuel Section 4
- See orevious concurrence - 4 /
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.-IMUFiGL 316 MBB DOCKET N0.: ~70-36 LICENSEE: Combustion Engineering FACILITY: Hematite, Missouri
SUBJECT:
CATEGORICAL EXCLUSION FOR AMENDMENT OF LICENSE SNM-33 TO INCREASE THE-U-235 ENRICHMENT. LIMIT TO 5.0 PERCENT By letters dated December 28, 1987, April 29, 1988, and June 6, 1988, Combustion Engineering submitted for NRC review and_ approval an_ application for amendment of License No., SNM-33 tc increase the U-235 enrichment limit '
from 4.1 to,5.0 percent. There will be no quantitative change in effluent discharge and only a slight change in qualitative aspects of effluent discharge.
Therefore, no environmental compromises are involved. Criticality safety analyses by the licensee and NRC staff demonstrate that the present safety margin provided by limiting the k-effective of a unit or an array of units to
<0.95 will continue to be maintained for the-processing and storage of uranium
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enriched to 5.0 w/o. Thus, the increase in the uranium enrichment authorized for possession andfuse at the facility does not significantly increase the potential for a nuclear criticality accident. Accordingly, the staff has concluded that the ;following conditions have been met:
- 1. There is no significant change.in the types or significant increase in the amounts of any effluents that may be released offsite,
- 2. There is no significant increase in individual or cumulative occupational radiation exposure,
- 3. There is no significant construction impact, and
- 4. There is~ no significant increase in the potential for or consequences from radiological-accidents.
Therefore, in accordance with 10 CFR 51.22(c)(11), neither an Environmental Assessment nor an Environmental Impact Statement is warranted for this proposed action.
FOR THE NUCLEAR REGULATORY COMMISSION LC6@W.L mm 3Y:
Leland C. Rouse, Chief Fuel Cycle Safety Branch DISTRIBUTION: Division of Industrial and Docket No. 70-36 PDR NMSS R/F Medical Nuclear Safety, NMSS ,
IMUF R/F IMSB R/F VTharpe GBidinger (2) Region III GJackson, LFMB GFrance, RIII GMcCorkle, SGLB SHO NRC File Center ;
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.. f.... .:.THUF y NAME:GlaRoche: ht/mh/1g:VLT rpe :GH8idinger :JJSwift . CRo se DATE: 06M /88 :0 / 8 :06/1388 :06/ 19 88 :06/// /88 0FFICIAL RECORD COPY