ML20150F377

Forwards Comments on Draft Programmatic Eis,Suppl 3 Which Evaluates Util Proposed post-defueling Monitored Storage of TMI-2.All Identified Alternatives Are Safe & Present No Significant Effect to Offsite Public or Environ

ML20150F377
Person / Time
Site:	Three Mile Island
Issue date:	07/12/1988
From:	Standerfer F GENERAL PUBLIC UTILITIES CORP.
To:	Masnik M NRC
References
NUDOCS 8807180263
Download: ML20150F377 (20)

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GPU Nuclear Corporation f/

}y g gf Post Office Box 480 Route 441 South Middletown, Pennsylvania 17057-0191 717 944 7621 TELEX 84 2386 Writer's Direct Dial Nurnber; (717) 948-8461 July 12,1988 4410-88-L-0097/0400P Dr. Michael T. Masnik Senior Project Manager OWFN 13D16 US Nuclear Regulatory Comission Washington, DC 20555

Dear Dr. Masnik:

Three Mile Island Nuclear Station, Unit 2 (TMI-2)

Operating License No. DPR-73 Docket No. 50-320 Draft Programmatic Environmental Impact Statement, Supplement No. 3 This letter transmits comments concerning the draf t Programatic Environmental Impact Statement (PEIS), Supplement No. 3, which evaluates GPU Nuclear's proposed Post-Defueling Monitored Storage (PDMS) of Three Mile Island Unit 2 (TMI-2).

GPU Nuclear is pleased that the Staff has confinned that the PDMS configuration is environmentally safe and that the benefits of long-term storage of TMI-2 outweigh any potential effects. Further, we want to stress that the dominant issue inherent in a decision to pursue PDMS is reduced occupational radiation exposure to the TMI-2 workforce. Included in the attached comments are results of a recently completed GPU Nuclear study which estimated worker radiation exposure for the PDMS proposal and for the NRC identified alternative of additional decontamination activity. These estimates, which were not available when the Supplement No. 3 Draft was prepared, indicate a significantly larger benefit in reduced occupational radiation exposure than presented in the PEIS Draf t.

Based on the PEIS Draft Supplement No. 3 and our attached comments, GPU Nuclear concludes that there is every reason to identify the PDMS proposal as the preferred alternative. All of the identified alternatives are safe and present no significant effect to the off-site public or the environment. The PDMS proposal, consistent with the basic NRC principle for radiation exposure of "as-low-as-is-reasonably-achievable" (ALARA), additionally offers a significant reduction in the radiation exposure to the TMI-2 workforce. GPU Nuclear believes this makes it clearly preferrable to the other alternatives.

GPU Nuclear Corporation is a subsidiary of the General Public Utilities Corporation v 8807180263 880712 i g PDR ADOCK 05000320 m PNU

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' July 12 , . 1988

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- If you have any further Questions on these' comments, we-will be pleased to answer them.-

Sincerely,-

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F. R. S anderfer v

- Director, TMI-2 EDS/ emf'

. Attachment-cc: Senior Resident Inspector, TMI - R. J. Conte Regional Administrator, Region 1 W. T. Russell Director, Plant Directorate IV - J. F. Stolz Systems Engineer, TMI Site - L. H. Thonus -

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ATTACHMENT

, 4410-88-L-0097

GENERAL COMMENT

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1. eneral Comment No. 1 - Preparation for PDMS The discussion of "Preparations for PDMS," Page 3.6, Section-3.2.1.2, should be revised to include the prerequisites that GPU Nuclear has established for PDMS. These prerequisites are described in the December 1986 plan. Further, it should be stated that after THI-2 is initially placed in PDMS, some activities may continue until completed.

Activities which may be carried on subsequent to the implementation of PDMS include:

1. Water Processing - Due to the anticipated duration of the ongoing adjudicatory process on the disposal of Accident Generated Water (AGW),

it is expected that AGW disposal will be ongoing into PDMS. Because certain systems and facilities (e.g., the Processed Water Storage Tanks) are needed to support this activity, they will not be placed in a final storage configuration until after initial implementation of PDMS.

2. . Decontamination - During the initial stages of PDMS, removal or isolation of small sources of radioactivity or radioactive material may continue (e.g., actions needed to place AGW disposal support systems in a final PDMS condition).

3. Radioactive Waste - Completion of shipment of remaining wastes generated during the Cleanup Program will be accomplished. Thus, radioactive waste shipments will continue during PDMS until all packaged waste from THI-2 cleanup activities has been shipped off-site.

4. SNM Accountability - Activities to complete the transfer records for the fuel debris which was shipped to the Department of Energy will continue.

In summary, THI-2 will be prepared to enter PDMS upon completion of the ongoing Cleanup Program (see General Comment No. 2 below). While some activities may continue for a period following implementation of PDMS, these activities will not alter the NRC assessment of environmental impact.

General Comment No. 2 - Completion of the Cleanup Program GPU Nuclear's THI-2 "Cleanup Program" includes those actions necessary to recover from the accident and to place the plant in a safe and stable condition that poses no risk to the public health and safety. The key elements of this program will be accomplished as a prerequisite to implementing PDMS. The use by the NRC of the terms "immediate cleanup" and '

"delayed cleanup" do not make clear that extensive cleanup has been accomplished and that the planned "Cleanup Program," as defined in the various PDMS documents, will be completed prior to PDMS. More accurate terminology for NRC's two alternative cases would be "immediate additional decontamination" and "final decontamination as part of decommissioning."

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. 4410-88-L-0097' Additional near-term activities, while further reducing remaining radioactive contamination at TMI-2, are not necessary to ensure the public health and safety and are not consistent with the ALARA principle. These activities are not part of the "Cleanup Program" but rather will.be accomplished as an integral element of decommissioning. This distinction should be addressed in the PEIS since these additional activities, whenever accomplished, will require considerable occupational exposure with no measurable increase in the margin of safety afforded by PDMS.

General Comment No. 3 - Worker Radiation Exposure The NRC has included estimates of the occupational radiation exposure for the PDMS proposal and.the primary alternative action. GPU Nuclear has recently completed a task by task study of the occupational radiation exposure for these alternatives and these estimates are summarized in Table 1. These GPU Nuclear estimates indicate a significantly larger person-rem savings than is indicated in the Draft PEIS. Thus, there is a greater ALARA incentive to adopt the PDMS proposal over the primary alternative. Moreover, if, as GPU Nuclear has proposed, final disposition of THI-2 occurs at the time of THI-2 decommissioning, tt. person-rem savings could be even larger.

Consistent with the original PEIS TMI-2, NUREG-0683, 1981, GPU Nuclear views the occupational dose savings as the dominant consideration in evaluating the PDMS alternative. The PEIS should emphasize that the PDMS condition poses no risk to public health and safety; in fact, the potential releases from THI-2 during this period are expected to be much less than those analyzed in NUREG-Oll2, "The Final Environmental Impact Statement Related to the Operation of Three Mile Island Nuclear Station, Unit 2." On balance, the significant reduction in occupational exposure as a result of PDMS more than offsets even the maximum hypothetical environmental effect. Thus, a clear advantage for PDMS is demonstrated.

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ATTACHMENT

. 4410-88-L-0097 TABLE 1

SUMMARY

OF GPU NUCLEAR PERSON-REM ESTIMATES IMMEDIATE. POST-PDMS ADDITIONAL DECONTAMINATION ACTIVITIES (Person-Rem) (Person-Rem)

~ REACTOR BUILDING' Preparations / Support Activities Cnaracterization 30 - 60 10 - 30-Ventilation Control and Area Isol, .0 - 0 0- 0 Health Physics Support 1110 - 2450 370.- 820 Engineering Support 60 - 130 30 - -60 Basement General Cleanup 1340 - 2940 .530 - 1160 Basement Cubicle Cleanup 1290 - 2840 430 -950 Basement Block Mall Removal 180 - 400 100 - 210 D-Ring Dose Reduction 710 - 1550 180 - 390-D-Ring Final Decon 740 - 1630 280 - 610 Dome and Polar Crane Decon 20 - 40 0- 10 El. 347'-0" Decon/ Dose Reduction 70 - 160 20 - 40

.E1, 347'-0" Final Cleanup 370 - 820 90.- 210 E1. 305'-0" Decon/ Dose Reduction 120 - 260 30 -- 60 El. 305'-0" Final Cleanup 570-- 1260 140 310 '

System Decontamination .

e _Reacter Coolant System 10 - 20 0- 10 Non-RCS Systems 60 - 130 30 - 70 Subtotal (Reactor Building) 6680 - 14690 2240 - 4940 AUXILIARY'AND FUEL HANDLING BUILDINGS Preparations / Support Activities Characterization 10 - 10 0- 0 Health Physics Support 20 - 50 0- 10 Engineering Support 0- 0 0- 0 AFHB Decon/ Dose Reductior 100 - 220 20 - 40 Subtotal (AFHB) '130 - 280 20 - 50 RADHASTE MANAGEMENT 360 - 550 180 - 280-PDMS TASKS 0- 0 230 - 490 APPR0XIMATE RANGE OF PERSON-REM EXPOSURE 7200 - 15500 2700 - 5800

• APPROXIMATE SAVINGS INCURRED BY IMPLEMENTATION OF PDMS 4500 - 9800 0400P L_

ATTACHMENT 4410-88-L-0097 General Comment No. 4 - Practicality of Continued Near-Term Work As a practical matter, "immediate cleanup,' .vhile useful as a hypotHeally bounding case for assessing the environmental impact of t5e PDMS pi y ni, is not a viable alternative. To continue cleanup activities in the special case of THI-2, beyond those currently planned, would require a substantial plannlag and engineering effort as well as the development of new technology and tooling. It is likely that addltional work would require the use of destructive decontamination techniques. Therefore, such an undertaking would constitute, in effect, a new program comparable to decommissioning and would result in generation of significant quantities of abnormal waste which would require disposal. The current low-level waste disposal capacity and system of allocations are not adequate to accept an influx of the large volume of normal and abnormal wastes which would require disposal. The GPU Nuclear proposal is to enter PLMS and subsequently undertake further decontamination as part of plant decommissioning. In the interim, it is likely that the total volume of future radwaste could be reduced because of efficiencies gained in packaging and volume reduction as a result ef develeping technologies. Thus, from a radwaste disposal perspective, there is a clear advantage to placing the plant in PDMS.

As stated, in our December 1986 plan, PDMS assures a continued safe and stable TMI-2 plant condition until the time of decommissioning of THI-i, at which time bech units could be decommissioned simultaneously. Two clear advantages result.

1. The possibility of decommissioning activities at THI-2 affecting operations at THI-1 is eliminated.

2. By performing a common function for both facilities, the workforce can be utilized more efficiently.

The NRC's new decommissiong rule, 10 CFR 50.82(b)(111), specifically recognizes the presence of other nuclear facilities at the site to be a factor in datarmining the appropriate timeframe for completing a decommissioning safely.

Recognition of these issues and consideration of the associated advantages to be realized by placing TMI-2 in PDMS should be included in this PEIS.

G 1 neral Comment No. 5 - PEIS Summary Table S-1 Table S.1, which summarizes and compares the impacts from NRC's "delayed cleanup" and "immediate cleanup" alternatives does not compare the two alternative cases on a common timeframe. As a result, GPU Nuclear believes it does not present an accurate comparison of these alternative cases.

GPU Nuclear has developed a suggested revision to Table S.1 which portrays a comparison of like activities. He use a common timeframe and the NRC data, except for the occupational exposure estimates where we use the GPU Nuclear estimates from Table 1.

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. 4410-88-L-0097

-The three major chang 6s to Table S-1 are proposed by GPU Nuclear:

1. Compare the'two alternatives over the same time period (24 years) so that time dependent factors (e.g., cost, off-site radiation exposure) can be co ;;ted on_the same basis; 2 '. Compara radiological exposures due to these activities to natural backgiound radiation exposure to highlight'their relative insignificance;

-and ,

3. Divide Table S.l'into three separate parts so that similar impacts are more readily compared.

In addition, it is suggested that an appendix (or reference) addressing collective occupational person-rem estimates be-provided to facilitate an understanding of the bases of the PEIS estimates. This appendix should be based on the GPU Nuclear study summarized in Table 1. The GPU Nuclear ,

person-rem estimates are significantly higher than those presented in the PEIS. The principal contributors (i.e., 60%) are Reactor Building basement and D-Ring activities where personnel access currently is limited. Although PDMS envisions maximum use of advanced robotics, such application will be limited in some areas (e.g., D-Rings) and management of personnel exposure will be key. Therefore, the natural decay process during PDMS, which will result in a significant decrease in work area dose rates, will significantly decrease personnel exposure and, in some cases, the scope of work required. A detailed analysis of occupational person-rem costs, the results of which are summarized-above, is in the process of publication and will be forwarded as Appendix 1A of the Post-Defueling Monitored Storage Safety Analysis Report.

The resultant suggested revisions to the Draf t PEI'i Table S-1 are attached as:

1. Revised Table-S Radiation Dose Impacts

2. Revised Table S Potential Health Impacat

3. Revised Table S Other Impacts 0400P

REVISED TABLE S-1 -

.I RADIATION DOSE IMPACTSa NRC Immediate Naturalb NRC Post-PDMS Cleanup Alternative Background Cleanup Alternative Plus 20-yr Storage- Radiation (24 yr) (24 yr) (24 yr)

Impacts Occupational Dose 2670-5760 person-rem 7170-15520 person-rem N/A Sone Dose to the Off-site Population Maximally Exposed Individual 0.00ld to 0.03C rem 0.00ld to 0.009c rem 4.08 rem Total Population 9d to 20c person-rem 7C to 9d person-rem 9 million person-rem Total Body Dose to the Off-site Population Within a 50-M11e Radius of THI-2

• Maximally Exposed Individual 0.0005d to 0.004c rem 0.0005d to 0.001C rem 7.20 rem Total Population 2d to 11C person-rem 2d to 3C person-rem 16 million person-rem FOOTNOTES:

a Off-site doses include the contribution from the NRC's 4-year additional decontamination effort and the contribution from airborna .eleases only during a 20-year storage period.

! b Natural background radiation doses are based on NCRP-93 and are calculated based on individual doses of 0.17 remfyr

{ bone dose and 0.30 rem /yr total body dose. A population of 2.2 million was used to calculate the person-rem.

c These doses were calculated by the NRC and represent bounding conditions. There is.no significant difference in the alternatives based on environmental impact. All doses are well below 17. of ni ural background radiation. -

d. These doses were calculated for the GPU Nuclear PDMS storage proposal as presented in the Environmental Evaluation for PDMS. They are adjusted for a 24-year time period to coincide.with the NRC dose calculations. Doses were calculated using actual source terms. Based on actual experience and technical data for the period 1983-87, these data assume equivalent releases for periods of active decontamination and PDMS.

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REVISED TABI.E S-2 s

POTENTIAL HEALTH IMPACT NRC Immediate NRC Post-PDMS Cleanup Alternative Natural Cleanup Alternative Plus 20-yr Storage Incidence Projected Total No. of Cancer Deaths for:

Off-site Population 0.001a o,0004 352,000a Worker Population 0.4 to 0.8 1 to 2 160b Projected No. of Genetic DisordersC 0.2 to 0.4 0.5 to 1 1,100,000 (off-site population)

Individual Risks to Off-site Population Cancer Less than Less than 1/6c 1/2,000,000,000d 1/5,000,000,000 Genetic Disorder -Less than Less than 1/10 1/27,000,000 1/11,000,000 Explanation of Health Risk:

a This value implies that there is approximately 1 chance in 1000 that a single fatal cancer may occur among the 2.2 million person off-site population. Moreover, the natural cancer mortality rate among 2.2 million persons is about 352,000 cases.

b The natural incidence of cancer deaths for the worker population is 16% of the estimated workforce of 1000 required for the cleanup phase of either NRC alternative.

c Genetic disorders are calculated for the equilibrium condition which includes 5 generations for the 2.2 million persons for a total of 11 million individuals. Worker exposure dose almost exclusively accounts for genetic disorder values and is incorporated into the off-site population since future generations of radiation workers are the members of the public.

d The average individual cancer risk due to PDMS and additional NRC-defined decontamination activities would be 1 chance in 2 billion. For the average individual, the natural risk of dying from cancer is approximately 1 chance in 6.

ATTACHMENT

. -4410-88-L-0097-REVISED TABLE S-3 OTHER IMPACTS NRC Immediate NRC Post-POMS- Cleanup Alternative Cleanup Alternative Plus 20-yr Storage (24 yr) (24 yr)

Cost ($ Million) 200-320 240-320a Radioactive Haste Burial 33,000 to 32,000 to Ground Volume 74,000 ft3b 70,000 ft3 Estimate Number of Traffic 0.5 to Ic 1 to 3 Accidents.

Estimated Number of Traffic 0.3 to 0.6c 1 to 3 Injuries Estimated Number of Traffic 0.02 to 0.05c 0.1 to 0.2 Fata11tles

a. The cost is based on the NRC estimate of $170 to $240 million to perform "immediate cleaaup" plus the NRC estimate of $3.8 million per year for 20 years to maintain the plant in a stored condition. The cost estimates are used for purposes of comparing alternatives and do not reflect actual GPU Nuclear cost estimates. The initial GPU Nuclear estimate of the relative cost indicates the NRC's "immediate cleanup" alternative would be more costly.

b. Advances in waste reduction and packaging technology should result in a reduction in the overall waste volume for this alternative,

c. An assumed reduction in the distance travelled to the off-site burial site, coupled with anticipated waste volume reductions, should cause the degree to which the environmental assessment favors the NRC's "delayed cleanup" to increase.

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- 4410-88-L-0097 General Comment No. 6 - Residual Fuel The goal of the current defueling program is to remove greater than 99% of the fuel. The Reactor Vessel (RV) will be defueled to the extent that subcriticality can be ensured. We_ call to the Staff's 4ttention the information contained in Technical Specification Change Request No. 53, submitted via GPU Nuclear letter 4410-87-L-0042 dated April 23, 1987, and approved by License Amendment No. 30 dated May 27, 1988, which noted that.the quantity of residual fuel in the RV may exceed 70 kg. The final quantity of fuel remaining in the RV will be reported as part of the Defueling Completion Report in accordance with Technical Specification 1.3.

The source term available for environmental releases is relatively insensitive to the quantity of residual fuel in the Reactor Vessel as the fuel is contained and subcritical. Thus, the overall conclusions of the PEIS do not change because this fuel ~will be contained within the Reactor Vessel and cannot contribute to the Reactor Building atmospheric release source term.

Bounding calculations for purposes of total environmental assessment need not await the Defueling Completion Report. They can be performed now based on an assumed residual fuel inventory of 1% of the original core inventory.as indicated in the discussion of the comparison of NRC's cleanup alternatives in Section 3.0, page 3.1, of the PEIS.

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_. N SPECIFIC COMMENTS Summary and Nomenclatu're v/ Footnote .See General. Comment No. 6 concerning residual fuel in RV.

xxi/ALARA --Should'use definition from 13 CFR 20.1

.xxv1 - M1111 roentgen and mrem are not units of radioactivity. They are units:

for measuring radiation exposure either in-air (roentgens).or-in humans (rem).

_,xxvill/SDS - In addition to radioactive. cesium, the Submerged Demineralizer System was-designed to remove radioactive strontium and many other radioactive isotopes ~present in the radioactively contaminated water.it precesses.

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Section 1 Introduction Pages 1.1, 2.30, 2.31, 3.1 - GPU Nuclear currently estimates that at least.99%

of the originalsfuel inventory will;be removed prior.to entry into PDMS.

Thus, for purposes of this document, it should be assumed that 1% of.the original fuel inventory remains at THI-2. (See General Comment No. 6.) GPU Nuclear is unable to duplicate'the estimated 0.16 percent value' quoted.on Pages 2.30 and 2.31' based on the estimated residual fuel values provided by GPU Nuclear on Page 11 of the December 1986 report. 'i N

Pages 1.1, 2.16 - The extent of Reactor Coolant System decontamination activity is limited to fuel removal and draining of the Reactor Coolant System to the extent practical.

Page 1.1 - Treatment of radioactive liquids may not be completed prior;to entry into PDMS as it is likely that Accident-Generated Water processing and disposal will be underway. Treatment of Accident-Generated Hater.is analyzed separately in PEIS Supplement No. 2.

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• ATTACHMENT 4410-88-L-0097 Section 2 Background Information Affecting Cleanup Alternatives Page 2.4/Section 2.1.1 - (Second Paragraph) - At the end of 1987, the general area exposure rates at the 347' elevation were approximately 25 to 35 mR/hr, with less than 35 mR/hr for most well-travelled areas.

Page 2.9/Section 2.1.1 - (Second Paragraph) - The last sentence should read, "In addition, a layer of sludge was deposited on the basement floor."

Page 2.11/Section 2.1.1 - As stated in our General Comment No. 2, GPU Nuclear considers the "Cleanup Program" to be completed prior to entry into PDMS.

Page 2.ll/Section 2.1.1 - Depending on the radioactivity levels of the Reactor Building basement water, processing may be through SDS and EPICOR II or only through EPICOR II. This distinction should be acknowledged.

Page 2.11/Section 2.1.1 - Work being performed in the Reactor Building basement prior to entry into PDMS is primarily being performco in Quadrants 1 and 2.

Page 2.12/ Figure 2.7 - Tne data presented in this figure should be clarified.

The radiation exposure rates are not general area exposure rates but rather are exposure rates obtained by use of a shielded directional probe. Most of the data is derived from contact readings. Even the general area readings are highly directional and do not give an accurate representation of actual general area exposure rates. Thus, the actual general area exposure rates, taken with a non-directional probe, would be lower than the contact exposures rates but higher than the general area exposure rates identified on this figure.

Page 2.13/Section 2.1.2 - The latter stages of defueling will require cutting through the lower grid plates and flow distributor forging in the lower core support assembly.

Page 2.13/Section 2.1.2 - The final storage location of the Reactor Vessel components has not been selected; however, they will be stored in suitable locations to minimize the potential for migration of fuel or activity to uncontained areas of the Reactor Building. Suggested rewording of this sentence would be: "After defueling, reactor internals may be returned to the vessel or stored in other suitable locations in the Reactor Building such as under shielding in the refueling canal."

Page 2.13/Section 2.1.2 - The statement that "Defueling will continue until all the fuel accessible, throughout the reactor vessel, has been removed," may not be accurate. GPU Nuclear will remove as much fuel from the reactor vessel as can be achieved, based on technology, criticality concerns, and ALARA considerations. Some fuel which is accessible (e.g., thin films on Reactor Vessel componentO may not be practicable to remove.

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. 4410-88-L-0097 Page'2.16/ Table'2.1 - This table should be annotated to reflect that'the estimated core material distribution in the' Reactor Vessel is as of December 31, 1987, as stated in-the text on Page 2.13.

Page 2.28/Section 2.2.2.3 - The estimate for "somewhat soluble ~ fission products".was calculated based on the ratio of an estimated 21,000 curies of total cesium remaining to the original estimate-of 660,000 curies; 1.e.. 3.2%

'of the original' activity remaining in the Reactor Building. However, in deriving this estimate, approximately 15,000 curies of cesium' remaining in the "D"-Rings were not considered; thus, the estimate of the remaining "somewhat solubla fission products" increases to 5.5% of the original value.

Page 2.29/Section 2.2.2.3 - The Cs-137:Sr-90 ratio for the 3000 pst concrete slab wall is approximately 2:1 vice 24:1.

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v.  : . ATTACHMENT-4410-88-L-0097 Section 3 Proposed And Alternative Plans for Completion of THI-2 Cleanup Page 3.1/Section 3.0 - Based on-current status of the adjudicatory process for Accident-Generated Hater (AGH) disposal, there may be AGH in the Auxiliary and fuel' Handling Buildings when THI-2 enters PDMS, Specifically, the Fuel Pools may not yet be drained.

• Page 3.1/Section 3.0 - The scope of the GPU Nuclear proposal is limited to placing THI-2 in a PDMS condition. Additional activity and the final disposition of the plant subsequent to PDMS has not been studied nor is it now proposed.

Page 3.2/ Table 3.1 - The radiological goal of <35,000 mR/hr for the Reactor Building Basement general area exposure rate is based on the expected dose rates in the basement folicwing the planned scope of work. The actual conditions in the Reactor Building Basement, following the completion of the current scope of the cleanup activities, are expected to range from 1 R/hr to greater than 100 R/hr based on the success of those activities in the various areas of the Reactor Building 83asement. The limiting factors will be accessibility and ALARA conditions.

Page 3.4/Section 3.1.5 - The no action alternative should be evaluated on the basis that all preparation for PDMS has been completed and THI-2 has been placed in a safe, stable, and secure condition that represents no risk to public health and safety.

Page 3.6/ Section 3.2.1.1 - Presently the only items identifled to be preserved for future use following PDMS are the mechanical components of the Polar Crane.

Page 3.6/Section 3.2.1.1 - These sections imply that the current environmental Page 3.9/Section 3.2.1.3 monitoring program at THI will be maintained Page 4.12/Section 4.1.4 unchanged throughout PDMS. However, both GPU Nuclear's December 1986 Peport on PDMS and our March 1987 Environmental Evaluation state that the environmental monitoring program at THI undergoes continuous review and modification in response to changing site and plant conditions. This process is expected to continue during PDMS, However, an adequate and appropriate site environmental monitoring program will be maintained throughout PDMS to provide coverage for THI-I and TMI-2.

Page 3.7/Section 3._2.1.3 - The current plan for monitoring effluents during Page 3.13/Section 3.2.2.1 passive airflow conditions is to periodically (semi-annually) perform an assay of the HEPA filter. Based on a known filter efficiency, the total particulate release to the environment can be determined. Since filter deposition is cumulative, this method provides determinative monitoring of breather effluents on a continuous basis.

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. 4410-88-L-0097 Page 3.8/ Table 3.2 - Although not specifically defined in previous GPU Nuclear submittals, the continuous sump level monitoring referred to in Table 3.2 is via an alarm function. Remota level measuring devices are not planned.

Page 3.10/Section 3.2.1.4 - Principal post-PDMS activities required to restore the plant to a condition similar to a normal plant at end of Ilfe include decontamination of Reactor Coolant System and connecting systems and cleanup of the Reactor Building, especially the basement and inside the 0-Rings. PDMS is a logical "hold point" prior to decommissioning. The next step (i.e.,

accomplishment of these post-PDMS activities) logically is a part of decommissioning of the plant.

Page 3.14/Section 3.2.2.1 - Radionuclides specifically associated with the fuel debris are located in the Reactor Coolant System and connected piping systems.

Page 3.16/Section 3.2.2.1 - An assumption that 10'/. of activation products become airborne appears to be overly conservative since this activity is interstitially bound to the material it is contaminating.

Page 3.21/Section 3.2.2.2 - These accident analyses assume failure of both Page 3.36/Section 3.3.2.2 stages of a double-stage HEPA-filter at the "most critical time". This double failure event should be characterized as a very low probability event.

Page 3.23/Section 3.2.2.2 - GPU Nuclear plans to deactivate the SDS system upon completion of AGH disposal; thus, SDS would not be available for post-PDMS activities. A more appropriate assumption is that contaminated 11gulds would be prccessed by EPICOR II prior to storage in an outside storage tank pending subsequent disposal.

Page 3.26/Section 3.2.4 - Preparation for PDMS could generate some Class 8 waste due to the relatively high Sr-90 concentration in contamination at THI-2. Based on present experience, the estimated ratio of Class A to Class B waste would be approximately 20:1.

Page 3.26/Section 3.2.4 - Radioactive waste would not necessarily be shipped off-site as it is generat9d. Normal procedures call for waste to be staged on-site until a sufficier. volume is generated to make up a full shipment.

Page 3.26/ Table 3.14 - The amount of waste listed under "Preparations for PDMS" appear low. GPU Nuclear currently estimates that 38,000 cubic feet of waste will be generated in 1988 with another 9000-18,000 cubic feet estimated for 1989. Of this volume, approximately 4000-5000 cubic feet would be Class A waste directly related to preparation for PDMS.

Page 3.27/Section 3.2.4 - Most Class A waste does not require shipment in a Page F.1/F.1 licensed shipping cask in order to comply with the NRC and 00T regulations. Most of this Class A waste is shipped in unshielded containers of 98.5 ft3 or 1014 ft 3, 0400P

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Page 3.27/Section 3.2.4 -'The 142 ft3 casks licensed for shipment of Class C waste are also licensed for shipment of Class B wastes.

4 Page 3.27/Section 3.2.4 - The assumption that the regional disposal facility.

will be 500 miles from the TMI site appears to be overly conservative since the low-level radioactive waste disposal site will be located in Pennsylvania.

Page 3.27/Section 3.2.4 - In discussing the unique arrangement between GPU Page 3.40/Section 3.3.4 Nuclear and the U.S. Department of Energy (DOE) to dispose of waste classified as greater than Class C, it should be noted that the current GPU Nuc1bar contract with the DOE for this service expires December 31, 1989. Disposal of such waste after that time will require negotiation of a new contract.

Pace 3.34/Section 3.3.2.1 - The Submerged Demineralizer System (SDS) should not be assumed to be operable for purposes of analysis of the "immediate decontamination" alternative. GPU Nuclear plans to deactivate'the~SDS system upon completion of AGH disposal.

Page 3.40/ Table 3.23 - Table 3.23 should include the dose estimate for the 20-year storage. period after the so-called "immediate cleanup" alternative to provide a more valid comparison to "delayed cleanup." Based on Table 3.13, values of 3-20 person rem for this period would be appropriate.

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Comparison.of' Environmental Impact of Delayed and Immediate Cleanup l:f Page 5.3/Section 5.1 - This discussion refers to an assumed'. average background

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. dose rate of 87 mrem /yr. The recently revised value of 300 mrem /yr, as

. -' defined in NCRP Report No.~93, should be incorporated.

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' Appendix F

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Waste Volume Estimates and Haste fransportation Impacts Page F.3/ Table F. The. radionuclides Tc-99 (0.3 C1/m3) and.H-3 (700 r C1/mJ) should be adaed to_the list of isotopes present at TMI-2 in order to ensure the accuracy of Footnote-(a).

Page F.16/Section'F.2.4 - GPU-Nuclear experience indicates that shipping container-leases for type B casks-typically average $2000/ day.

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