ML20236H134
| ML20236H134 | |
| Person / Time | |
|---|---|
| Site: | Quad Cities  |
| Issue date: | 07/27/1987 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20236H096 | List: |
| References | |
| NUDOCS 8708050068 | |
| Download: ML20236H134 (20) | |
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WASHINGTON, D. C. 20555
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i SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATING TO ACCEPTANCE OF THE OFFSITE DOSE CALCULATION MANUAL (0DCM)
UPDATED THROUGH REVISION 11 COMMONWEALTH EDISON COMPANY I
QUAD CITIES NUCLEAR POWER STATION, UNITS NOS, 1 AND 2 DOCKET NOS. 50-254 AND 50-265
1.0 INTRODUCTION
On June 19, 1984 the staff issued Amendment Nos. 89 and 84 to Facility Operating License Nos. DPR-29 and DPR-30 for the Quad Cities Nuclear Power Station, Unit Nos. I and 2. The amendments incorporated Radiological Effluent Technical Specifications (RETS) into Quad Cities Technical Specifications ,
(TS). Section 6.8 of these TS references an Offsite Dose Calculation Manual (0DCM) and prescribes the methods for its change.
2.0 EVALUATION The submittal of a Quad Cities ODCM, Revision 10 dated September 1983, by Commonwealth Edison Company (CECO, the licensee) received NRC approval by letter dated June 19, 1984 from R.B. Bevan to the licensee. Several discrepancies found in the review of the submittal were, however, to be corrected in the next revision of the ODCM. In accordance with toad Cities Technical Specification 6.8 the licensee addressed these discrepancies in the Quad Cities Monthly Operating Report for July 1986 and submitted as Revision ll, a complete package of revised site specific pages for the Quad Cities ODCM.
8708050068 070727 DR ADOCK 050 4 L_
2-The Quad Cities ODCM, Revision 11, dated December 1985 has been reviewed for use by EG&G laaho Incorporated (EG&G), as part of a technical assistance contract program. The contractor's Technical Evaluation Report (TER), which is enclosed as Appendix D from EGG-PHY-7240, provides a detailed technical evaluation of the licensee's submittal using NRC criteria. The staff has reviewed thit; report, and agrees that Quad Cities ODCM, Revision 11, generally describes; documented and approved methods which are consistent with the methodology and guidelines in NUREG-0133.
In the next revision of this ODCM, CECO should address those " exceptions" listed in the . conclusions section of contractor's TER. Furthermore, the following special conments (listed below) by the staff regarding two l of the exceptions should also be addressed in the next ODCM revision. The licensee has previously addressed the deviation of the inhalation pathway calculation from NRC criteria, generically, in the ODCM Requirements Section submitted as Attachment A to the May 1985 Dresden Monthly Operating Repurt.
This response is acceptable to the staff for Quad Cities on the condition it isdocumentedasoutlinedinexception1),below.
- 1) The ODCM inhalation pathway calculation used dose rate for an infant rather than that for a child.
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It is the present staff understanding that the calculation of limiting gaseous effluent dose rate, corresponding to the inhalation pathway, be made with respect to the thyroid of a child instead of an infant. The basis for this is that the dose rate due to the combination of breathing N
rate and dose factor for a child is more restrictive than dose rate (due to the same combination) for an infant. On the other hand the licensee states they used the infant in their calculation because existing computer software was more readily changed to the infant parameter than to the child.
The staff will consider.this operational' deviation acceptable for Quad Cities, but on condition that the licensee incorporates the following items into in the next Quad Cities ODCM revision.
- a. A statement, simi~lar to the narrative above, explaining that the dose rate due to a child is more restrictive than to an infant, and is the dose rate to be used for TS 3.8.A.I.b.
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- b. A statement, similar to that in Attachment A of the May 1985 Dresden Monthly operating Report, as to why the licensee is using the dose rate for an infant.
- c. Incorporate a factor in the inhalation dose calculation to account l for lack of conservatism in the infant calculation.
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- 2) Dilution water flow rate used in ODCM calculation is much larger than the maximum of ?.0 X 10 3 cfs allowed in NUREG-0133 for a two unit plant site.
3 The licensee should change the ODCM to use a value of 2.0 X 10 cfs or provide (in the ODCM) an explanation as to why, when this higher value is used, the dose calculated is still to the maximum exposed member of the public.
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3.0 C3NCLUSIONS i, The Quad Cities ODCM, Revision 11, updated through April 30, 1987, is an acceptable reference for use witn' Quad Cities TS 6.8.- The changes
.s incorpdE.ted in Revision 11 are in compliance with Quad Cities TS 6.8.B.
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It shcold also be noted, that figur6'8.1 I w. 3$ :in6d ertently withheld from
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the contractor's' copy of the Quad Cities,00CM.' The staff has conf t(ned the ,
' i presence of this figure a*d f%r.d it to be an apprgpriato presentation of eff%ent pathways. '
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Enciasure: EGG Appendix D -\
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APPENDIX 0 1
Evaluation of Changes to the ODCM !
for the Quad Cities Nuclear Power Station l I
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D.1 EVALUATION OF CHANGES TO THE 00CM The Commonwealth Edison Company (CECO), the Licensee for the Quad f Cities Nuclear Power Station, prepared an Offsite Dose Calculation Manual (ODCM) consisting of a generic section common to all nuclear facilities operated by Ceco and site-specific sections (Sections 7.0 and 8.0) for each of the Utility's nuclear f acilities. The present version of the generic section is Revision 11 dated March 1985 suomitted to NRC with .
letter dated April 26,1985.[13 The present version of site-specific 1985 [2]
Section 8.0 for Quad Cities is Revision 11 dated December Changes to the 00CM are' containing changes reported by the Licensee.
required by the Licensee's Technical Specifications to be reported to NRC in the Monthly Operating Reports. The ODCM changes were submitted by NRC to EG&G Idaho for review.
These changes have been incorporated into the Licensee's existing ODCM and reviewed.as a whole. The result of the evaluation is intended to be a stand-alone document, and is given in Supplement 1 to Appendix 0.
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D.4 REFERENCES-
- 1. Letter from K. Licari (Ceco) to D. Eisenhut (NRC),
Subject:
Offsite Dose Calculation Manual, April 26, 1985.
. 2. Letter from Ceco to NRC,
Subject:
Revision 11 to "Offsite Dose Calculation Manual List of Tables for Quad-Cities Section 7.2.", December 1985.
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O SUPPLEMENT 1 to i
1 APPENDIX D i
EVALUATION OF CHANGES TO THE ODCM f 0
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INTRODUCTION purpose of Review The purpose of this document is to review and evaluate the changes made to the Offsite Dose Calculation Manual (00CM) by the Licensee of the The.00CM is a supplementary document Quad Cities Nuclear Power Station.
for implementing the Radiological Effluent Technical Specifications (RETS) in compliance with 10 CFR 50, Appendix I requirements.E13
- Scope of Review As specified in NUREG-0472E23 and NUREG-0473,E33 the 00CM is to be developed by the Licensee to document the methodology and approaches used to calculate offsite doses and maintain the operability of the radioactive effluent systems. As a minimum, the 00CM should provide equations and l methodology for the following topics:
o Alarm and trip setpoints on effluent instrumentation o Liquid effluent concentrations in unrestricted areas o Gaseous effluent dose rates at or beyond the site boundary o Liquid and gaseous effluent dose contributions l
o Li kuid and gaseous effluent dose projections.
1 In addition, the ODCM should contain flow diagrams, consistent with the systems being used at the station, defining the treatment paths and the components of the radioactive liquid, gaseous, and solid waste management systems. A description and the location of samples in support of the environmental monitoring program are also needed in the 00CM.
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plant-Scecific Backaround On behalf of Quad Cities Station, the Commonwealth Edison Company (CECO) submitten a change to the CECO 00CM[43 in a Monthly Operating Report issued by the Licensee.[5] The Licensee issued Revision 11 to site-specific Section of the generic 00CM.
The Licensee's changes to the 00CM were transmitted to an independent review team at the Idaho National Engineering Laboratory (INEL) for review. The 00CM review was conducted and the results and conclusions of '
the evaluation are presented in this supplement.
REVIEW CRITERIA Review criteria for the 00CM were provided by the NRC in three documents:
NUREG-0472, RETS for PWRs[2]
NUREG-0473, RETS for BWRsE33 NUREG-0133, Preparation of RETS for Nuclear Power Plants.[6]
In the 00CM review, the following NRC guidelines were also used:
" General Contents of the Offsite Dose Calculation Manual,"
Revision 1,E73 and Regulatory Guide 1.109.[8] The 00CM format is left to the Licensee and may be simplified by tables and grid printouts.
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EVALUATION The Licensee has followed tlx methodology of NUREG-0133[6] to ;
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I determine the alarm and trip 'setpoints for the liquid and gaseous effluent monitors, to provide reasonable assurance that the maximum permissible concentrations (MPCs), as specified in 10 CFR 20,E93 will not be exceeded by discharges from various liquid or gaseous release points. )
There are three radioactive liquid release pathways for the'two-unit site:
discharges from the radwaste treatment. system, discharges from the Unit 1 service water system, and discharges from the Unit 2 service water system. Revision 11 to the ODCM states that radwaste releases are currently monitored for radioactivity using grab samples and a composite sample and that installation of a continuous monitor for the radwaste discharge line is in progress. Additionally, each unit's main service water effluent header is monitored for radioactivity by analyzing grab samples for gross beta activity and that installation of a new continuous monitor for both service water headers is in progress. It is not clear when the monitors will be in service and it is assumed the Licensee remains in compliance with the Technical Specification for the radioactive liquid effluent instrumentation. Simplified flow diagrams for the liquid effluent system are shown in Figures 8.2-1 and 8.2-2 of the ODCM. The Licensee's setpoint calculational method for the liquid effluent monitors described in site-specific Section 8.0 of the ODCM is consistent with the guidelines of NUREG-0133.
There are two radioactive gaseous effluent release pathways for the i two-unit site: radioactive gases from each reactor building's ventilation system are collected in a common header before release at the reactor building ventilation stack and the two units share a common main chimney for the remainder of the gaseous releases. Noble gases from each reactor building's ventilation system are monitored prior to introduction to the ventilation stack. Offgas effluents from each unit's steam jet air ejector are monitored prior to introduction to the main chimney and the monitors are capable of isolating the offgas release pathway. The simplified flow diagram for the gaseous radwaste and gaseous effluent flow
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1 pathways referenced as Figure 8.1-1;in the ODCM is missing from the ODCM.
. The Licensee's setpoint calculational method for-the gaseous effluent monitors described in site-specific Section 8.0 of the ODCM is consistent with the guidelines of NUREG-0133.
The Licensee's ODCM contains the methods and calculational relation-ships that are used to compare the radioactivity concentrations in liquid effluents at the point of release to the 10 CFR Part 20 limits prior to the release and.after the release.
Noble gas discharges are assured to be within the NUREG-0473 dose. rate limits by correctly determining the setpoints for the noble gas monitors.
Section 2.1.2.2 of the generic 00CM states'that the maximum dose rate to any organ from all radionuclides, radioactive materials in' particulate form and radionuclides other than noble gases with half-lives greater than 8 days shall be limited to < 1500 mrem / year.' The text of the generic ODCM "
includes more radionuclides than are required by the gaseous effluent dose rate technical specifications for any of the plants within the CECO system. CECO prepared a generic ODCM with the intention of addressing the technical specification requirements for all plants within the Ceco 1 system. A difficulty arises in that not all plants within the Ceco system have their technical specifications patterned after the same version of NUREG-0472 for PWRs or NUREG-0473'for BWRs. Specifically, the Quad Cities Technical Specification 3.8 A 1.b states "For iodine-131, for iodine-133, and for all radionuclides in particulate form with half-lives greater than 8 days less than 1500 mrem / year." This list restricts the.nuclides to I-131, I-133, and to all particulate with half lives greater than 8 days and does not include tritium. Although tritium is not specifically identified in the technical specification it is inferred since it is a requirement of 10 CFR 20. The dose rate due to the release of I-131, I-133, tritium, and particulate with half-lives greater than eight days is assured to be within the NUREG-0473 limit of 1500 mrem per year by calculating the dose rate to any organ of an infant via the inhalation pathway due to the actual release using the highest calculated annual average relative concentration X/Q used for estimating dose to an D1-6 L
1 individual. However, Draft 7" of Revision 3 to NUREG-0473 Identifies inhalation as the most limiting pathway with the child's thyroid as the !
critical organ instead of any organ of an infant.
Doses to a member of the public due to radionuclides identified in liquid effluents are calculated monthly to show compliance with 10 CFR 50 A; pendix I. The Licensee identifies the fish and water consumption i pathways for the dose calculations assuming the adult as the maximum I exposed individual. The dilution water flow in Table 7.2-1 of the Quad ]
Citle's ODCM is 4.7x104 cfs which is larger than the maximum of 2.0x103 '
cfs allowed in NUREG-0133 for a two unit plant (a comparable situation ;
exists for the Dresden and LaSalle plant's). Consequently the dose is not to the maximum exposed member of the public because of the high dilution 1 flows. Additionally the bioaccumulation factor for P-32 in Table 7.1-12 of the ODCM should be 3x103 instead of 1x105 pCi/kg per pCi/ liter.
Doses resulting from the release of noble gases and radiolodines, tritium, and particulate with half lives greater than eight days are calculated monthly to show compliance with 10 CFR 50 Appendix 1. The I highest calculated annual average relative concentrations for X/Q are used to calculate the maximum air doses. The Licensee identifies the ingestion and inhalation pathways to calculate doses,for the maximum exposed member in the infant and adult age groups and the ground exposure pathway for all age groups. The dose calculation methodology in the ODCM due to radioactive gaseous effluents satisfies the relationships presented in NUREG-0133.
Methodology, based on dose projections, to determine required use of the liquid and gaseous radwaste treatment systems is described in the ODCM. The projections are based on the dose calculations due to radioactive effluents which sr.tisfy the relationships in NUREG-0133.
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The ODCM contains simplified flow diagrams illustrating the treatment paths and the components of the radioactive liquid, gaseous and solid waste management: systems. However, Figure 8.1-1 illustrating the gaseous radwaste and effluent flow diagram is missing from the submittal.
Methodology for demonstrating compliance to 40 CFR 190 is described in the 00CM. The Licensee's RETS and the ODCM state the time period is over (
l 12 consecutive months instead of over a calendar year which is permitted 1 l
by Draft 7" to Revision 3 of NUREG-0473. The Licensee's RETS and 00CM '
states that compliance to 40 CFR 190 will be demonstrated if the doses-exceed the quarterly or annual dose limits of the Technical
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Specifications. This is a conservative requirement since Draft 7" to I Revision 3 of NUREG-0473 requires compliance to be demonstrated when twice the quarterly or twice the annual dose limits are exceeded.
Specif'ic parameters of distance and the direction sector from the centerline of a reactor and additional information have been provided for each and every sample location in the RETS Environmental Monitoring Table 4.8-4, ODCM Table 8.4-1,and 00CM Figures 8.4-1, 8.4-2, and 8.4-3.
Table 7.2-7 of the 00CM identifies the relative D/Q value at the nearest milk cow and Table 8.4-1 identifies the milk sampling locations. It is not clear why milk sampling location Q-17 in the ENE sector identified in Table 8.4-1 was selected instead of a different location from Table 7.2-7 having the largest D/Q. Additionally, it would seem that a better location for the fish sample would be closer to the discharge pipe instead of location Q-24 which is 15 miles downstream as identified in i Table 8.4-1.
In summary, the Licensee's 00CM as revised uses documented and approved methods that are generally consistent with the methodology and {
guidance in NUREG-0133, and therefore is an acceptable reference.
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. . l CONCLUSIONS The Licensee's Revision 11 to', site specific Sections 7.0 and 8.0 in conjunction with Revision 11 to the generic ODCM for Ceco uses documented and approved methods and are consistent with the criteria of NUREG-0133 with the following exceptions:
o It is not clear when the liquid effluent radwaste and service water monitors will be installed and placed in service. In the interim, the ODCM states the Licensee is monitoring the releases by analyzing grab samples. !
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o The text of generic Section 2.1.2.2 includes more nuclides than are required by Quad Cities Technical Specification 3.8.A.1.b or by NUREG-0473 Technical Specification 3.11.2.1.
o As described in Section 2.1.2.2 the dose rate due to I-131,
! tritium, and particulate with greater than eight-day half lives is determined for any organ of an infant via the inhalation l l
' pathway. The dose rate calculation should be made for the thyroid of a child via the inhalation pathway to be in agreement with Draft 7" of Revision 3 to NUREG-0473.
4 o The dilution water factors in Table 7.2-1 are larger than the values recommended in NUREG-0133, o The bioaccumulation factor for P-32 in Table 7.1-12 should be 3x103 .instead of 1x10 5 pCi/kg per pCi/ liter.
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- o. It is not clear why milk sampling' location Q-17 in-the ENE sector.
-identified in Table 8.4-1 was. selected instead of a different location from Table 7.2-7 havinga. larger D/Q.
o It appears that a better location for the fish sample would be nearer to the liquid discharge point instead of 15 miles downstream at location Q-24.
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REFERENCES 4
- 1. Title 10, code of Federal Regulations, Part 50, Appendix I, " Numerical Guides for Design Objectives and Limiting Conditions for Operation to Meet the Criterion, "As low As Is Reasonably Achievable," for I Radioactive Material in Light-Water-Cooled Nuclear Power Reactor Effluents".
- 2. " Radiological Effluent Technical Specifications for Pressurized Water Reactors," Rev. 3, Draft 7", intended for contractor guidance in reviewing RETS proposals for operating reactors, NUREG-0472, September 1982.
- 3. " Radiological Effluent Technical Specifications for Boiling Water Reactors," Rev. 3. Draft 7", intended for contractor guidance in reviewing RETS proposals for operating reactors, NUREG-0473 September 1982.
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- 4. Letter from K. Licari (CECO) to D. Eisenhut (NRC),
Subject:
Dose Calculation Manual, April 26, 1985.
- 5. Letter from Ceco to NRC,
Subject:
Revision 11 to "Offsite Dose Calculation Manual List of Tables for Quad-Cities Section 7.2.", December 1985.
- 6. " Preparation of Radiological Effluent Technical Specifications for Nuclear Power Plants, A Guidance Manual for Users of Standard Technical Specifications," NUREG-0133, October 1978.
- 7. " General Contents of the Offsite Dose Calculation Manual," Revision 1 Branch Technical Position, Radiological Assessment Branch, NRC, February 8, 1979,
- 8. " Calculation of Annual Doses to Man from Routine Releases of Reactor Effluents for the Purpose of Evaluating Compliance with 10 CFR 50, Appendix I," Regulatory Guide 1.109, Rev. 1, October 1977.
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- 9. Title 10, Code of Federal Regulations, Part 20, " Standards for Protection Against Radiation."-
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