ML15112A984
| ML15112A984 | |
| Person / Time | |
|---|---|
| Site: | Oconee, Vermont Yankee  |
| Issue date: | 11/24/1980 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML15112A982 | List: |
| References | |
| NUDOCS 8101100471 | |
| Download: ML15112A984 (9) | |
Text
PARE~u UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON. D. C. 20555 ENVIRONMENTAL IMPACT APPRAISAL BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDMENT NO.90 TO FACILITY OPERATING LICENSE NO. DPR-38 AMENDMENT NO.90 TO FACILITY OPERATING LICENSE NO. DPR-47 AMENDMENT NO. 87 TO FACILITY OPERATING LICENSE NO. DPR-55 DUKE POWER COMPANY OCONEE NUCLEAR STATION, UNITS NO. 1, 2 AND 3 DOCKETS NOS. 50-269, 50-270 AND 50-287 1.0 Introduction and Discussion A Final iGeneric Environmental Impact Statement (FGEIS) on Handling and Storage of Spent Light Water Power Reactor Fuel (NUREG-0575, Volumes 1-3) was issued by the Nuclear Regulatory Commission (NRC) August 1979. The NRC staff evaluated and analyzed alternatives handling and storage of spent light water power reactor fuel with emphasis on long range policy.
Consistent with the long range.policy, the storage of spent fuel addressed in the FGEIS is considered to be interim storage to be used until the issue of permanent disposal is resolved and implemented.
One spent fuel storage alternative considered in detail in the FGEIS is the expansion of the onsite fuel storage capacity by modification of the existing spent fuel pools (SFPs).
On the date of issuance of the FGEIS (August 1979), 40 applications for SFP capacity expansions were approved with the finding in each case that the environmental impact of the proposed increased storage was negligible. However, since there are variations in storage pool designs and limitations caused by the spent fuel already stored in some of the pools, the FGEIS recommends that licensing reviews be done on a case-by-case basis to resolve plant specific concerns.
In addition to the alternative of increasing the storage capacity of the existing SFPs, other spent fuel storage alternatives are discussed in detail in the FGEIS. The finding of the FGEIS is that the environmental impact-costs of interim storage are essentially negli gible, regardless of where such spent fuel is stored. A comparison of the impact-costs of the various alternatives reflect the advantage of continued generation of nuclear power versus its replacement by coal fired power generation. In the bounding case considered in the FGEIS, where spent fuel generation is terminated, the cost of replacing nuclear stations before the end of their normal lifetime makes this alternative uneconomical.
-2 This Environmental Impact Appraisal (EIA) incorporates the appraisal of environmental concerns applicable to expansion of the Oconee Units 1 and 2 SFP.
For additional discussion of the alternatives to increasing the storage capacity of existing SFPs, refer to the FGEIS. This EIA consists of three major parts plus a summary and conclusion. The three parts are:
(1) descriptive material, (2) an appraisal of the environmental impacts of the proposed action, and (3) an appraisal of the environmental impact of postulated accidents.
1.1 Description of the Proposed Action By application dated July 25, 1980, as supported by letter dated July 1, August 7 and 14, October 15 and 31, November 3 and December
, 1980, Duke Power Company (the licensee) requested an amendment to Facility Operating Licenses Nos. DPR-38, DPR-47 and DPR-55 for the Oconee Nuclear Station, Units 1, 2 and 3. The proposed amendment would allow an increase in the storage capacity of the Oconee Units 1 and 2 common SFP from 750 to 1312 storage locations.
The environmental impacts of the ONS as designed, were considered in the Final Environmental Statement (FES) relative to the continuation of con struction and operation of ONS issued March 1972. The purpose of this EIA is to determine and evaluate any additional'environmental impacts which are attributable to the proposed increase in the SFP storage capacity of the Station.
1.2 Need for Increased Storage Capacity The ONS consists of three generating units with a licensed power of 2,568 MWt for each unit. Units 1 and 2 share a common SFP with a storage capacity of 750 storage locations.
Unit 3 has a pool with a.capacity of 474 storage locations. All three units have 177 fuel assemblies in each core.
The modifications evaluated in this EIA are the proposals by the licensee to increase the pool storage capacity from 750 to 1312 spaces in the Oconee Units 1 and 2 common SFP.
The proposed increase would be accomplished by replacing the existing fuel storage racks with new, more compact, neutron absorbing racks.
The proposed rack design uses a-nominal 10.65-inch center-to-center spacing in each direc tion. The old racks had a~nominal 13.75-inch center-to-center spacing in each direction. This modification would extend spent fuel storage capability past mid 1987 compared to early 1983 with the current capacity. The increase in capacity would extend the capability for a full core discharge from late 1982 to late 1986. This capability, while it is not needed-to protect the health and safety of the public, is desirable in the event of a need for a reactor.vessel inspection or repair. Such off-load capability would reduce occupational exposures to plant personnel.
-3 Currently, spent fuel is not being reprocessed on a commercial basis in the United States. The Nuclear Fuel Services (NFS) plant at West Valley, New York, was shutdown in 1972 for alterations and expansion; on Septaber 22, 1976, NFS informed the Commission that they were withdrawing from the nuclear fuel reprocessing business. The Allied General Nuclear Services (AGNS) proposed plant in Barnwell, South Carolina, is not licensed to operate.
The General Electric Company's (GE)
Morris Operation (MO) in Morris, Illinois, is in a decommissioned condition. Although no plants are licensed for repro cessing fuel, the storage pool at Morris, Illinois,and thestoragq pool at We.st Valley, New York (on land owned by the State of New York and leased to NIFS through 1980), are licensed to store spent fuel.
The storage pool at West Valley is not full but NFS is presently not accepting any additional Spent fuel for storage, even from those power generating facilities that had contractural arrangements with NFS. GE is also not accepting any addi tional spent fuel for storage at the MO.
Construction of the AGNS receiv ing and storage statioh has been completed. AGNS has applied for, but has
/ not been -granted, a license to receive and store irradiated fuel assemblies in the storage pool at Barnwell prior to a decision on the licensing action relating to the separation of facility.
1.3 Radioactive Wastes The station contains waste treatment systems designed to collect and pro cess the gaseous, liquid and solid waste that might contain radioactive material. The waste treatment systems are evaluated in the ONS FES dated March 1972. There will be no change in the waste treatment systems des cribed in Section V.0 and Appendix 111.3 of the FESlbecause of the proposed modirfication.
1.4 SFP Cseanup System The SFP cooling and cleanup system consists of two circulation pumps, two heat exchangers, two filters, an ion exchanger, and the required piping, valves and instrumentation. This equipment is in two separate loops.
The pumps draw water from the pool.
This flow is passed through the heat exchangers and then returned t o the pool.
Approximately 100 gpm in each loop is bypassed through the filter and ion exchanger to maintain the clarity and purity of the water.
Therefore, because we expect only a smiall increase in raditoactivity released to the pool water as a result of the proposed modifi cation as discussed in Section 22, we conclude the SFP cleanup system is adequate for the proposed modification and will keep the concentrations of radio activity in the pool water to acceptably low levels.
2.0 Environmental re te topolse Action 2.1 Nonradiological The environmental impacts of OilS, asndesigned, were considered in the FES.
Increasing the number of assemblies stored in the existing Units 1 and 2 common fuel pool will not cause any new environmental impacts.
The amounts of waste heat emitted by ONlS will increase slightly (less than one percent), resulting in no measurable increase in impacts upon the environment.
-4 2.2 Radiological 2.2.1 Introduction The potential offsite radiological environmental impacts associated with the expansion of the Units 1 and 2 common spent fuel storage capacity was evaluated and determined to be environmentally insigni ficant as addressed below.
The additional spent fuel which would be stored due to the expansion is the oldest fuel which has not been shipped and should have decayed at least six years. During the storage of the spent fuel under water, both volatile and nonvolatile radioactive nuclides may be released to the water from the surface of the assemblies or from defects in the; fuel cladding.
Most of the material released from the surface of the assemblies consists of activated corrosion products such as Co-58, Co-60, Fe-59 and Mn-54 which are not volatile. The radionuclides that might be released to the water through defects in the cladding, such as Cs-134, Cs-137, Sr-89 and Sr-90, are also predominantly nonvolatile.
The primary impact of such nonvolatile radioactive nuclides is their contribution of radiation levels to which workers in and near the SFP would be exposed. The volatile fission product nuclides cf most con cern that might be-released through defects in the fuel cladding are the noble gases (xenon and krypton), tritium and the iodine isotopes.
Experience indicates that there is little radionuclide leakage from spent fuel stored in pools after the fuel has cooled for several months.
The predominance of radionuclides in the 'SFP water appear to be radionuclides that were present in the reactor co6lant system prior to refueling (which becomes mixed with *water in the SFP dur ing refueling operations) or crud dislodged from the surface of the spent fuel during transfer from the reactor core to the SFP.
During and after refueling, the SFP purification system reduces the ra dioactivity concentrations considerably. It is theorized that most failed fuel contains small, pinhole-like perforations in the fuel clad ding at the reactor operating condition of approximately 8OF.
A few weeks after refueling, the spent fuel cools in the SFP so that the fuel clad temperature is relatively cool, approximately 180*F.
This substantial temperature reduction should reduce the rate 'of re lease of fission products from the fuel pellets and decrease the gas pressure in the gap between pellets and clad, thereby tending to retain the fission products within the gap. In addition, most of the gaseous fission products have short half-lives and decay to insignificant levels
ge
-5 within a few months. Based on the operational reports submitted by the licensees or discussions with the operators, there has not been any sig nificant leakage of fission products from spent light water reactor fuel Stored in the MO (formerly Midwest Recovery Plant) at Morris, Illinois, or at the NfS storage pool at West Vailoey, New York. Spnt fuel has been stored in these two pools which, while it was in a reactor, was determined to have significant leakage and was therefore removed from the core. After storage in the onsite SFP, this fuel was later shipped to either MO or NFS for extended storage. Although the fuel exhibited significant leakage at reactor operating conditions, there was no significant leakage from this fuelin the offsite storage facility.
2.2.2 Radioactive Material Released to Atmosphere With respect to gaseous releases, the only significant noble gas isotope attributable to storing additional assemDlies for a longer period of time would be Kryptofl-85.
As disc,.ssea previously, experience has demon strated that after spent fuel ha decayed 4 to 6 months there no Sig lonificant release of fission products from defective fuel. however, we have conservatively estimated that an a itioal So curies per year of Krypton-85 may be released when the modified pool is completely filled. This increase would result in an additional total body dose to an individual at the site boundary of less than.00008 mreml year. This dse is insinificant when compared to the approximately ou mrem/year that an individual receives from natural background radiation.
The additional total body dose to the estimated population withina 50 mile radius -of the plant is less than 0;003 man-rem/year.
This is less than the natural fluctuations in the dose teis population would receive from natural background radiation. Under our cosrvative assumptions, these expoapes represent an increase of less than 0.05% of the exposures from the station evaluated in the FES for the in~ivifual it the site bound ary and the population (Table VI.2).
Thus. we conclude that the proposed modification will not have any sianificant nor measurable impact on expo sures offsite.
Assuming that the spent fuel will be stored o nsite for several years, Iocifle-131 releases from spent fuel assemolies to the SFP waterwill not be significantly increased because of the expansion of the fuel storage capacity since the Iodine-131 inventory in the fuel will decay to negli gible levels between refuelings for each of the Oconee Units.,
Storino additional spent fuel assemblies is not expected to increase the bulk water temperature above the 150OF during normal rpfuelings used in the design analysis.
therefore, it is not expected that there will be any significant change in the annual release of tritium or iodine as a result of the proposed modification from that previously evaluated in the FES.
.1Most airborne releases from the station result from leakage,of realtor coolant which contains tritium and iodine in higher concentrations than the SFP.
Therefore, even if there were a higher evaporation rate from the SFP, -the increase in tritium and io-
-6 dine released from the station as a result of the increase in stored spent fuel would be small compared to the amount normally released from the station and that which was previously evaluated in the FES.
If it is desired to reduce levels of radioiodine, the air can be di verted to charcoal filters for the removal of radioiodine before release to the environment.
In addition, the station radiological effluent Technical Specifications which are not beinn changed by this action, limit the total releases of gaseous activity from ONS including the releases from both pools.
2.2.3 Solid Radioactive Wastes The concentration of radionuclides in the pool is controlled by the filters and ion exchanger and be decay of short-lived isotopes. The activity is highest during refueling operations while reactor coolant water is introduced into the pool, and decreases as the pool water is processed through a filter and ion exchanger. The increase of radio activity, if any, should be minor because the additional spent fuel to be stored is relatively cool, thermally, and radionuclides in the fuel will have decayed significantly.
While we believe that there should not be an increase in solid rad waste from the SFP operations due to the modification, as a conservative estimate we have assumed that the amount of solid radwaste may be in creased by 51 cubic feet of resin per year from the ion exchanger (an additional resin bed per year) and the filters (two additional filters per year). The estimated annual average amount of solid waste shipped from the ONS from 1973 to 1977 was about 37,000 cubic feet per year.
The annual average amount of solid waste shipped from Oconee Units 1 and 2 would be about 24,000 cubic feet per year. If the storage of addi tional spent fuel does increase the amount of solid waste from the SFP purification systems by about 51 cubic feet per year, the increase in total waste volume shipped would be less than 0.3% and would not have any significant environmental impact.
The present spent fuel racks to be removed from the SFP are contaminated and will be disposed of as low level waste.
The licensee has estimated that less than 11,540 cubic feet of racks will be removed from the SFP because of the proposed modification. The old racks will be shipped, uncompacted, to the Barnwell site in South Carolina. The licensee is able to do this as the Barnwell facility does not have restrictions on compaction for in-state facilities such as ONS. This enables the licensee to avoid incurring a 5 man-rem dose that compaction would incur.
The total waste shipped from the station will be increased by less than 0.5% per year when averaged over the lifetime of the station. This will not have a significant environmental impact, 2.2.4 Radioactivity Released to Receiving Waters There should not be a significant increase in the liquid release of radionuclides from the station as a result of the proposed modification.
The amount of radioactivity on the SFP filter and demineralizer might slightly increase due to the additional spent fuel in the pool, but this increase of radioactivity should not be released in liquid effluents from the station. The station radiological effluent Technical Specifi cations, which are not being changed by this action, restrict the total releases of liquid radioactivity from the station.
The cartridge filter removes insoluble radioactive matter from the SFP water.
This is periodically removed to the waste disposal area in a shielded cask and placed in a shipping container.
The insoluble matter will be -retained on the filter or remain in the SFP water.
The demineralizer resins are periodically flushed with water to the spent resin storage tank.
The water used to transfer the spent resin is decanted from the tank and returned to the liquid radwaste system for processing.
The soluble radioactivity will be retained on the resins. If any activity should be transferred from the spent resin to this flush water, it would be removed by the liquid radwaste system.
Leakage from the SFP is collected in the leak collection system which consists of stainless steel channels.imbedded in the concrete struc ture.
The leakage is transferred to one of the waste storage tanks ir the liquid radwaste system and is processed by the system before any.
water is discharged from the station.
Before the waste storage tank, the leakage flows through an open basin where the flow could be observed.
The basin is inspected periodically for signs of pool leakage. There have not been signs of leakage from the pool. Any leakage from the pool that could occur during the modification of the pool could also be detected through an increase in make-up water to the pool or an unusual increase n the level in a waste storage tank.
2.2.5 Occs We have reviewed the licensee's plan for the removal and disposal of the low Adensity racks and the installation of the high density racks~ with respecttro occupdtioflal radiation exposure. The licensee performed a similar pool modil fication in mid-1979 and bases the estimated exposures on observed exposures accumulated in the 1979 modification. The occupational exposure for the entire operation is estimated by the licensee to be about 23 man-rem. We consider this to be a reasonable estimate'because it is based on observed dose rates and occupancy factors for individuals performing a specific job during the modification. This operation is expected to be a small fraction of the total man-rem burden from occupational exposure.
We have estimated the increment in onsite occupational dose resulting from the proposed increase in stored fuel assemblies-on the basis of information supplied by the licensee for occupancy times and dose rates in the SFP area.
The spent fuel assemblies themselves will contribpte a negligible amount to dose rates in the pool area because of the depth of water shielding the fuel.
The occupational radiation exposure resulting from 'the proposed action repre sents a negligible burden. Based on preselit and' projected operations in the SFP area, we estimate that the proposed modification'should add less than one percent to the total annual occupational radiation.exposure burden at this facility.
Thus, we conclude that storing additional fuel in the SFP will not result in any significant increase in doses received by occupational workers.
-8 2.2.6 Impacts of other Pool Modifications As discussed above, the additional radiological environmental impacts in the vicinity of ONS resulting from the proposed modifications are very small fractions (less than 1%) of the impacts evaluated in the ONS FES.
These additional impacts are too small to be considered anything but local in character.
Based on the above, we conclude that a SFP modification at any other facility should not significantly contribute to the environmental impact of the ONS and that the ONS SFP modification should not contribute'signi ficantly to the environmental impact of any other facility.
3.0 Environmental Impacts of Postulated Accidents Although the new high density racks will accommodate a larger inven tory of spent fuel, we have determined that the installation and use of the racks will not change the radiological consequences of a postu lated fuel handling accident or spent fuel cask drop accident in the SFP area from those values reported in the FES for Oconee,Units 1 and 2 dated March 1972.
The environmental impact of a spent fuel shipping cask fallino into the Oconee Units 1 and 2 SFP or Oconee 3 SFP is given in the EIA dated Sept ember 10, 1976. These impacts are not changed because of the proposed modification of the Oconee Units 1 and 2 SFP.
Additionally, the NRC staff has underway a generic review of load handling operations in the vicinity of SFPs to determine the likelihood of a heavy load impacting fuel in the pool and, if necessary, the radiological con sequences of such an event. Because ONS will be required to prohibit loads greater than 3000 pounds (the normal weight of a fuel assembly, control rod and handling tool) to be transported over spent fuel in the SFP, we have concluded that the likelihood of any other heavy load handling accident is sufficiently small that the proposed modification is acceptable and no additional restrictions on load handling operations in the vicinity of the SFP are necessary while our review is underway.
4.0 Summary The FGEIS on Handling and Storage of Spent Light Water Power Reactor Fuel findings were that the environmental impact of interim storage of spent fuel was negligible and the cost of the various alternatives reflect the advantage of continued.generation of nuclear power with the accompanying spent fuel storage. Because of the differences in SFP designs the FGEIS recommended licensing SFP expansions on a case-by-case basis.
For ONS, expansion of the storage capacity of the SFP does not significantly change the radiulogical impact evaluated in the FES. As discussed in Section 2.2.2, the additional total body dose that might be received by an individual or the estimated pop ulation within a 50-mile radius is less than 0.00008 mrem/yr and 0.003 man rem/yr, respectively, and is less than the natural fluctuations in the dose this population would receive from background radiation. The occupational exposure for the modifications of the SFP is estimated by the licensee to be
-9 22.7 man-rem. Operation of the station with additional spent fuel in the SFP is not expected to increase the occupational radiation exposure by more than one percent of the total annual occupational exposure at the station.
5.0 Basis and Conclusion for Not Preparing an Environmental Impact Statement We have reviewed the proposed modifications relative to the requirements set forth in 10 CFR Part 51 and the Council of Environmental Quality's Guidelines, 40 CFR 1500.6. We have determined, based on this assessment, that the proposed license amendments will not significantly affect the quality of the human environment. Therefore, the Commission has determined that an environmental impact statement need not be prepared and that, pur suant to 10 CFR 51.5(c), the issuance of a negative declaration to this effect is appropriate.
Dated: December 24, 1980