ML20214Q475

Requests Exemption from Conversion from Use of Highly Enriched U,Per 10CFR50.64 & Listed Generic Ltr 86-12 Purposes.Justification Provided

ML20214Q475
Person / Time
Site:	05000054
Issue date:	09/18/1986
From:	Ruzicka W CINTICHEM, INC.
To:	Harold Denton Office of Nuclear Reactor Regulation
References
GL-86-12, NUDOCS 8609240371
Download: ML20214Q475 (7)

Text

r p.- 4 CINTICHEM, INC.

a wholly owned subsidier y of Medi-Physics, Inc. P.O. BOX 818. TUXEDO, NEW YORK 10987 [914] 351-2131 Sept ember 18, 1986 Mr. Harold R. Denton Director of the Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, DC 20555

Dear Mr. Denton:

The Nuclear Regulatory Commission's 10 CFR 50.64 Rule iImits the use of Highly Enriched Uranium in domestically licensed research reactors. This rule, though, provides for a " unique purpose" exemption from the requirement to convert from the use of HEU fuels if a licensee can justify an exemption to the NRC. This letter is Cintichem's request pursuant to 10 CFR 50.64 (c)(1) for this exemption and our reasoning why this exemption should be granted to us.

10 CFR 50.2 gives broad definitions for acceptable LEU unique purpose exemptions. The NRC's generic letter 86-12 dated July 3, 1986 gives more specific guidance when a licensee may qualify for an exemption. Two of the generic letter's qualifying purposes fit Cintichem's program welI. These

. purposes are:

1.) "A specific program or commercial activity (typically long term) that significantly serves the U.S. national interest and cannot be accomplished without the use of HEU fuel. This purpose is intended to rel9e to technical activities closely coupled to the national Interest, which might include preeminence in a specific field or assurance of a domestic supp,1y of some essential product o .eactor operation."

2) "A reseurch project based on neutron flux levels or spectra available only with HEU fuel. This purpose is intended to provide the opportunity to continue using HEU fuel if converting to available LEU fuel would ci ange neutron flux densities and spectra so that the fundamental reason for conducting the reactor based program would be compromised."

Listed below are six categories. Each category lists a separate topic relating to LEU at Cintichem and gives our reasoning why Cintichem should fit into the NRC's " unique purpose" exemption classification.

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Page 2 September 18, 1986 A. PURPOSE AND BENEFITS OF THE CINTICHEM FACILITY Cintichem's 5 W MTR research reactor and adjoining hot laboratory are used primarily for the production of medical radioisotopes. Target material is irradiated in the reactor core to produce the desired Isotopes. The radioactive targets are then transferred to the adjoining hot laberatory where the desired isotopes are chemically separated and packaged for shipment to hospitals and pharmaceutical firms throughout the world.

The Cintichem facility is the only commercial supplier ~of reactor-produced isotopes in the United States. It also produces a substantial share of the world's needs of these isotopes. One in every four patients in U.S.

hospitals benefits from a nuclear diagnostic procedure. Seventy percent of all nuclear diagnostic procedures are performed with reactor produced Isotopes, amounting to more than 60 milIlon diagnostic tests conducted yearly in the U.S.

Page one of this letter listed two purposes which would qualify a licensee to acquire an exemption. Purpose 1 relates to a program that a) serves the U.S. national Interest; b) involves preeminence in a specific field; and c) provides assurance of a domestic supply of an essential reactor product. Clearly, Cintichem's program f its into all three of these categories.

B. LOSS OF PRODUCT The NRC's Regulatory Analysis of its then proposed HEU rule expressed concerns about the societal cost from any loss of reactor capabilities.

It stated that for f acilitles above 1-2 W power, LEU conversion could have an impact un the source of neutrons necessary for production processes. Of most concern in the NRC's analysis was the capability to produce short-lived isotopes for medical research and diagnosis, which could be affected by temporary or permanent facility shutdowns or competitive market forces. The Regulatory Analysis stated, however, that the provisions of the rule are Intended to provide opportunity for minimizing any potential losses in f acility capabilities and availability.

We fully support.the NRC's concern for the societal cost of a reduction of the U.S.-produced radioisotope capacity. We also agree with the NRC's hope that the rule's provisions, notably the " unique purpose" exemption provision, can be used to minimize or eliminate this loss of domest!c reactor capabliItles.

SpactfIcally, Cintichem belleves that conversion of our reactor to Iow enriched fuel will have an adverse impact on the operating characteristics of the reactor for producing radioisotopes and other nuclear services.

The known reduction of thermal flux with LEU conversion is a major Concern.

The IAEA LEU Core Conversion Guidebook (IAEA-TECDOC-233 App. F-1 MTR Benchmark Calculations) concludes that a hardened neutron energy spectrum and an approximate 10% reduction in the thermal neutron flux can be expected af ter LEU conversion. This was confirmed in the Ford Reactor

Page 3~ September 18, 1986 B. LOSS OF PRODUCT (continued) conversion to LEU. Our reactor is basically a thermal neutron source for producing radioisotopes and performing nuclear Irradiation services. A 10% reduction in thermal neutron flux will result in a 10% reduction in product and productivity. The " harder" flux will also reduce the quality of our major service Irradiation work, neutron transmutation doping of electronics grade silicon.

The flux hardens with LEU conversion even while the power level of the core is maintained at 5 MW. Therefore, to produce the same number of thermal neutrons and correspondingly the same number of radioisotopes by thermal neutron !aduced nuclear reactions, the reactor power level would have to be increased by 10% _ The Cintichem reactor cannot easily be run

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at 5.5 MW. This is .due to the existing reactor plant's cooling capabilities and present power level licensing linits. . S imil arl y, radioisotope production could not be increased by increasing reactor operating time as we now operate at a greater than 95% duty cycle. The 5%

. down time is necessary for reacter maintenance and refueling. Other constraints dictated by product specifications, such as product half lives and induced long i Ived contaminates, also preclude the longer operating time as a solution to this problem. The neutron flux energy spectrum in

. LEU cores may also alter control rod worths, the ef fective delayed neutron

! fraction, and other important characteristics, all of which could change 1 operating margins. A reduction in rod worths could detrimentally ef fect l our duty cycle, requiring more refueling and reactor down time.

Page one of this letter Iisted purpose 2 as an accepted reason to achieve

, an exemption. It was intended to provide a lIcensee the opportunity to continue using HEU fuel if LEU conversion would change neutron flux

, density and spectrum so that the fundamental reason for a lIcensee's operation was compromised. As explained above, the 10% loss of product clearly compromises our program and this fact alone should justify granting Cintichem an exemption.

C. WASTE CLASSIFICATION Cintichem Irradiates uranium targets to produce fission product Isotopes.

Only a smalI portion of the fission product isotopes produced are marketable. The remaining isotopes are radioactive waste. This waste is presently classified via 10 CFR 61.55 as low level Class B radioactive waste. If LEU' fuel conversion at Cintichen is mandated, the hardened flux spectrum will change the waste characteristics and it could result in changing the ' waste category. This occurs because the hardened flux, t manifested by the reduction of thermal flux and the increase in epithermal

. flux, will increase Pu-239 production via the U-238 neutron-gamma reaction. This will, at a minimum, add a substantial cost to waste disposal, but at worst, could preclude our use of commercial Class B low level waste disposal areas.

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Page 4 September 18, 1986 D. REACTOR SAFETY The I AEA's LEU Core Conversion Guidebook (I AEA-TECDOC-233 Section 1.4.1) states that "the agreed criteria for LEU conversion is that safety margins and fuel reliability should not be lower than for current HEU designs".

Cintichem questions if this technical criteria for LEU conversion has been or can be achieved with the proposed LEU fuels. The presently used low density, high enriched fuels have been proven to be reliable over-approximately 30 years of normal operation in numerous reactors and also under accident conditions as demonstrated in the SPERT and BORAX tests.

Normal performance of the lower density LEU fuels has been modeled in computer codes and verified in operation, but performance under accident conditions has not been verified with experimental data. In the areas of safety and reliability the presently used aluminide and oxide HEU fuels are excellent. The new HEU fuel types, with dif ferent fuel densities and thermal conductivities, could alter the retention of the fission product source term and they should be fully understood under accident conditions before wholesale conversion to LEU is mandated.

We also anticipate numerous changes in core parameters with a changeover to an LEU core. Some of these parameters, notably the ef fective delayed neutron fraction and the control rod worths, could effect our safety margins and therefore require changes to our operating parameters, which could have a detrimental ef fect on our radioisotope program.

E. REQUALIFICATION OF PRODUCTS All the products and services provided by the Cintichem reactor were developed in an HEU core. If Cintichem's reactor were to convert to LEU, all these products and the product waste would have to be requalified.

Our major product is radlochemical grade Technetium-99m, a daughter of Molybdenum-99. This product would have to be requallfled for purity following LEU conversion. Our fission product waste is currently classified as Class B low level waste. LEU conversion would necessitate a reevaluation of the classification as transuranic isotopes in the waste would increase. Our predominant service irradiation is the neutron transmutation of electronics industry silicon. An LEU core, with its harder flux spectrum, would cause greater f ast neutron silicon crystal damage and would lower the quality of our Irradiation product. These are only three specific examples of product requalification concerns. Each of our products would have to be Individually analyzed and requallfled.

F. FINANCIAL & MARKET CONSIDERATIONS This section discusses the financial and radioisotope market consequences of Cintichem converting to LEU reactor f uel.

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Page 5 September 18, 1986 F. FINANCI AL & MARKET CONSIDERATIONS (continued)

A Cintichem LEU core resulting in a reduction of 10% in the flux / power ratio in the reactor core would result in a 10% overall reduction in the yield of a product for the same amount of work performed. This would increase the overall product cost proportionally by 10%. Our current assessment of the effect that converting to LEU reactor fuel will have on radioisotope costs includes other cost elements beside the reduction in thermal neutron flux. These changes are summarized in the following table.

Cost Factor Cost Factor / Total Cost Factor Estimated increase Total Cost increase Fuel Fabrication + 15% 4% < 1%

Flux / Power + 10% 100% 10%

Fuel Reprocessing + 20% 4% < 1%

Waste Disposal + 50% 12% 6%

Total 18%

The cost factors listed above are those which we can Identify at this time. Others will probably become evident as more experience is gained in f uel development and in reactor operation with LEU f uel.

The fuel fabrication estimate was provided by one manufacturer who has had minimum experience working with the relative higher density LEU loadings.

We believe our reactor will require the highest density fuel loading (greater than 4.5 gm U/cc) in order to maintain our present design metal / water ratio and f uel element burn up which is currently at > 50% of the fissionable material. This high density can only be achieved with silIcide fuel and, since fuel fabricators have had no ongoing production experience with this process, this estimate could be inaccurate.

The fuel reprocessing cost was developed by assuming that the DOE would continue this service and that the charges will continue to be based on the gross weight of the fuel processed. It is estimated that the LEU fuel will weigh about 20% more than the HEU fuel. If commercial fuel reprocessing is ever resumed, this number may change radically because it is assumed that DOE would defer to commerce in this function.

The waste disposal figure assumes that the transuranic content of our Isotope production waste will increase due to the hardened neutron flux in the core. The current effective production cross section for Pu, including the resonance integral, has been measured to be approximately 2/3 the maximum that is theoretically possible but a f actor of 2 above the thermal neutron capture cross section for this reaction. The difference is attributable to the resonance capture of epithermal neutrons. As the neutron flux spectrum hardens with LEU conversion, the Pu production increases. The amount by which it does has been conservatively estimated by applying the highest theoretical cross section. If the Pu content of the waste were deemed to exceed Part 61 limits, there is no practical method of estimating the added cost at this time because there is no t

current disposal method for such waste. This issue has the potential for terminating the business.

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Page 6 September 18, 1986 F. FINANCIAL & MARKET CONSIDERATIONS (continued)

These are the cost elements of radioisotope production that we now can predict will increase as a result of converting the reactor fuel to LEU.

The total estimated 18% increase applles to the routine, direct, ongoing expense of production. Since it is estimated that the conversion to LEU fuel cannot be accomplished until 1989 or 1990, other factors could develop that cannot be anticipated now. Not included in the above estimate are the costs that we can foresee that will be involved in the initial reactor conversion. There will be man-years of work in revising technical specifications, safety analyses, licenses, operating procedures, and training documents in addition to the work of the actual conversion.

Also of note here is that NRC's Regulation Analysis implied that the costs involved in an LEU conversion would only involve initial changeover costs.

As discussed above, this 18% Increase is an ongoing cost carried on Indefinitely after core conversion.

The above financial assessment just addresses the incremental ongoing radioisotope cost increase. Also a factor here is that an LEU conversion with. Its 10% less thermal flux could prevent us from meeting our customers' curie capacity requirements. We occasionally run at 100%

capacity and a 10% reduction in capacity could result in an isotope short fall, possibly resulting in our customers seeking alternate suppliers.

This loss of 10% capacity could not be casily accommodated by a 10%

increase in power level as cooling systems would have to be suppleinented.

Also, our present duty cycle of > 95% cannot be increased. This loss of capacity would damage us in the marketplace.

Other market considerations are that there are only a few major suppllers of reactor-produced radiochemicals in the world. We are the only commercial domestic supplier and we participate in a world market against competitors who are subsidized by their governments and who use HEU. We must emphasize that this business is conducted as a separate and distinct entity from the radiopharmaceutical Industry which it serves. The estimated cost increase wilI have to be fully absorbed wIthin this business and it will be very recognizable by the pharmaceutical manufacturers, who are our customers. If competing producers are not subject to the same cost pressures, we would be at a definite disadvantage. Since our competitors are not wholly commercial entities and they are not subject to the same regulations, we believe that we will be at a definite competitive disadvantage.

If Cintichem was forced out of the radioisotope business, it would be possible for other DOE operated reactors to fill the gap, but this could not be done immediately. A substantial lead-time would be required to Install irradiation and radiochemical processing f acilities to meet the production volume requirements. This became very evident when the General Electric Test Reactor (GETR) ceased operation in 1977. Fortunately, the Cintichem reactor had suf fIclent excess capacity at that time to fili a major part of the gap lef t by the GETR. The demand that we were not able to satisfy went to foreign suppliers. Our guess is that a DOE facility

Page 7 September 18, 1986 F. FINANCIAL & MARKET CONSIDERATIONS (continued) could not respond quickly enough to fill a future precipitous gap and therefore most of the demand would go to foreign sources. If current foreign suppliers could not fill the shortf all completely, there would be a shortage of supply for some indefinite period.

The exact gross sales that are generated from the sales of radioisotopes is considered by us to be business-confidential .information. We can say though that the sale of bulk radioisotopes is in the order-of-magnitude of 10's of millions of dollars. There are approximately 100 people directly involved in the production and distribution of bulk radioisotopes. It should be mentioned that the extension of the bulk radioisotope business into the manufacture of pharmaceuticals and research chemicals is an industry that employs thousands of people and ' generates a revenue of hundreds of millions of dollars.

Page one of this letter iIsted purpose 1 as being an acceptable reason for obtaining an LEU exemption. Cintichem feels that these financial and market considerations substantiate our bellef that we meet the objectives of purpose 1. Curtallment of our ability to produce and effectively market our products would not be in the national interest and would jeopardize a domestic supply of an essential reactor product.

CONCLUSION Cintichem submits that the use of our reactor fits into the 10 CFR 50.2 rule category of " unique purpose" for the above stated reasons and accordingly requests the exemption per 10 CFR 50.64. Cintichem has addressed this LEU issue in numerous earlier letters to the NRC and to the U.S. House of Representatives Committee on Science and Technology. If the Commission, in its review of this letter, requests more information or copies of our earlier letters, we will be happy to supply them.

Sincerely, W W ha y sL46~

Wlll1am G. Ruzicka Manager, Nuclear Operations WGR: mag Enclosures cc.: Mr. Herbert Berkow, NRC Mr. Hal Bernard, NRC

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