ML20198K263
| ML20198K263 | |
| Person / Time | |
|---|---|
| Site: | Nine Mile Point  |
| Issue date: | 12/18/1998 |
| From: | Mueller J NIAGARA MOHAWK POWER CORP. |
| To: | NRC |
| Shared Package | |
| ML20198K260 | List: |
| References | |
| NUDOCS 9812300392 | |
| Download: ML20198K263 (14) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION in the Matter of
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Niagara Mohawk Power Corporation
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Docket No. 50 220
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Nine Mile Point Unit 1
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APPLICATION FOR AMENDMENT TO OPERATING LICENSE Pursuant to Section 50.90 of the Regulations of the Nuclear Regulatory Commission, Niagara Mohawk Power Corporation (NMPC), holder of Facility Operatin0 License No. DPR-63 for Nine Mile Point Unit 1 (NMP1), hereby requests an amendment to the above-mentioned License.
4 The proposed change deletes license condition C(4) and license page 3B from the Operating License and deletes the requirement to maintain potassium iodide tablets at NMP1. NMPC committed to provide information demonstrating compliance with GDC-19 dose guidelines for the NMP1 Control Room in its letter dated May 23,1998 (NMP1L 1323). In a letter dated March 19,1984, NMPC provided its response to NUREG-0737, item lil.D.3.4, regarding NMP1 Control Room habitability. The 1984 submittal provides the base assumptions for the analyses and is the licensing basis for NMP1. Attachment E summarizes the assumptions and the results of updated analyses performed consistent with NMPC's 1984 response to NUREG-0737, item lli D.3.4. The analyses have been reperformed using a different computer code, which provided comparable results to that of the previous code. The results of the analyses demonstrate that the use of potassium iodide tablets is not required as a means to satisfy GDC-19 dose guidelines. Since the information requested by the license condition is included in Attachment E and is, therefore satisfied, this license condition is no longer required.
The proposed change will not authorize any change in the type of effluents or in the authorized power level of the facility in conjunction with this Application for License Amendment. The supporting information and analysis which demonstrate no significant hazards consideration pursuant to 10CFR50.92 are included as Attachment B.
WHEREFORE, Applicant respectfully requests that Facility Operating License No. DPR-63 be amended in the form attached hereto as Attachment A.
NIAGARA MOHAWK POWER CORPORATION By x
BEVERLY W. RIPKA n H. Muelfer-Notary Public Stateof New York Quu n o:* ego co. No. mW9 Senior Vice President and uy commisson Exp.
Chief Nuclear Officer Subscribed and Sworn to before me on this //
day of &m.4v1998.
eel.
A N0iARY PUBL'IC O
9812300392 981218 PDR ADOCK 050002 0 ;
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l ATTACHMENT A NIAGARA MOHAWK POWER CORPORATION LICENSE NO. DPR-63 DOCKET NO. 50-220 Proposed Channe to the Current Operatina License Delete existing page 3B of the operating license in its entirety.
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ATTACHMENT 8 NIAGARA MOHAWK POWER CORPORATION LICENSE NO. DPR-63 DOCKET NO. 50-220 Suncortina information and No Sinnificant Hazards Consideration Analysis INTRODUCTION This Application for Amendment to the Nine Mile Point Unit 1 (NMP1) Operating License deletes license condition C(4) and license page 3B from the Operating License and deletes the requirement to maintain potassium iodide (Kl) tablets at NMP1. Niagara Mohawk Power Corporation (NMPC) committed to provide information demonstrating compliance with GDC-19 dose guidelines for the NMP1 Control Room in its letter dated May 23,1998 (NMP1L 1323). The information requested is included in Attachment E.
By letter dated May 2,1998, as supplemented by letters dated May 21,1998 and May 23,1998 (three letters), NMPC proposed a license amendment to change the NMP1 Technical Specifications (TS). The proposed amendment was subsequently approved on May 23,1998 as Amendment No.161. The amendment changed TS 3/4.6.2, " Protective Instrumentation," to reflect modifications to the initiation instrumentation for the Control Room Air Treatment System. It also changed TS 3.2.4, " Reactor Coolant Activity," to revise the reactor coolant system radioactivity concentration limit.
Specifically, TS Tables 3.6.21 and 4.6.21, " Control Room Air Treatment System initiation,"
were changed to delete the high radiation signal and substituted other initiating signals from the Reactor Protection System. TS Table 3.6.21 was revised to specify the appropriate setpoints and instrument operability requirements. TS Table 4.6.21 was revised to state the appropriate surveillance requirements. Associated TS " Bases for 3.4.5 and 4.4.5 Control Room Air Treatment System" was also changed to update the system description consistent with the changes to the automatic initiation circuitry, and to reflect the system's manual start capability. TS 3.2.4a was revised to state that the reactor coolant system radioactivity concentration in water shall not exceed 9.47 (rather than 25) microcuries of totaliodine per gram of water. In a third letter dated May 23,1998, NMPC addressed the use of Kl tablets as a compensatory action and committed to submit new analyses and evaluations for meeting GDC-19 dose guidelines without reliance on Kl tablets.
Amendment No.161 also issued license condition C(4) on license page 38. The license condition states:
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"The licensee shall submit an application for license amendment, including supporting analyses and evaluations by December 18,1998. This amendment application shall contain the proposed methods for compliance with GDC 19 dose guidelines under accident conditions based upon system l
design and without reliance upon the use of potassium iodide."
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The information requested by the license condition is included in Attachment E.
Attachment E provides information regarding Control Room dose for the Loss of Coolant Accident (LOCA) and Main Steam Line Break (MSLB), consistent with the NMP1 Licensing Basis.
EVALUATION The assumptions and methods used to determine Control Room operator radiation exposure resulting from the LOCA or MSLB are discussed in Attachment E. As noted in Attachment E, the analyses determined anticipated Control Room operator radiation exposures from airbome radioactive material and direct radiation resulting from design basis accidents. For a design basis LOCA, sources of radiation included containment leakage, engineered safety feature leakage outside primary containment, and the lealcage through valves in lines that bypass the secondary containment. These sources of radiation contribute to airborne radioactivity levels in the Control Room and direct radiation in the form of shine from the overhead plume, secondary containment, and Control Room emergency ventilation filters.
The radiological consequences of a MSLB were similarly analyzed for airborne radioactivity levels in the Control Room.
in the case of the Control Room LOCA doses, the thyroid and whole body gamma dose results increased from those in 1984 based on the updated analyses. However, the
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Control Room doses still remain within the GDC-19 dose guidelines. The updated assumptions do not apply to the offsite doses.
In the' case of the Control Room MSLB doses, the thyroid dose results increased from those in 1984 based on the updated analyses. As noted in Table 1 of Attachment E, the updated analyses for the MSLB do not take credit for Control Room Air Treatment System filtration, whereas the previous analyses did. Even without filtration, the MSLB doses remain within the GDC-19 dose guidelines. Automatic actuation of the Control Room Air Treatment System would result from the MSLB initiation signals listed in TS Table 3.6.21, which would significantly reduce this value. The updated assumptions do not apply to the offsite doses.
CONCLUSION The information requested by license condition C(4)is provided in Attachment E. Even though some of the specific doses increased based on the updated analyses, the results of the study demonstrate adequate protection as it relates to GDC-19 dose guidelines under accident conditions without the use of KI tablets. Therefore, this license condition and the requirement to maintain KI tablets at NMP1 are no longer necessary and may be deleted.
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i Based on the above evaluation, it is concluded that there is reasonable assurance that the proposed change can be implemented without endangering the health and safety of the public.
NO SIGNIFICANT HAZARDS CONSIDERATION ANALYSIS According to 10CFR50.91, at the time a licensee requests an amendment to its operating license, the licensee must provide to the NRC its analysis using the standards in 10CFR50.92 concerning the issue of no significant hazards consideration. According to 10CFR50.92(c), a proposed amendment to an operating license involves no significant hazards considerations if operation of the facility in accordance with the proposed amendment would not:
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Involve a significant increase in the probability or consequences of an accident previously evaluated; or 2.
Create the possibility of a new or different kind of accident from any accident previously evaluated; or 3.
Involve a significant reduction in a margin of safety.
NMPC has evaluated this proposed amendment pursuant to 10CFR50.91 and has determined that it involves no significant hazards considerations.
The following analyses have been performed:
The operation of Nine Mile Point Unit 1. In accordance with the oronosed amendment will not involve a sinnificant increase in the probability or conseauences of an accident previousiv evaluated.
The information requested by license condition C(4)is provided in Attachment E. As previously noted, the Control Room LOCA doses to the thyroid and whole body increased from the previous analyses. However, the doses still remain within the GDC-19 dose guidelines. In the case of the Control Room MSLB doses, the thyroid dose also increased from the previous analyses. The updated MSLB analyses, however, assumed no credit for Control Room Air Treatment System filtration. The thyroid dose still remains within the GDC-19 dose guidelines. Automatic actuation of the Control Room Air Treatment System would result from the MSLB initiation signals listed in TS Table 3.6.21, which would significantly reduce this value. Therefore, the results of the analyses demonstrate adequate protection as it relates to GDC-19 dose guidelines under accident conditions without the use of Kl tablets. Deletion of the license condition and the requirement to maintain Ki tablets based on the updated analyses will not affect the ability of Control Room personnel to perform their function. No modifications or changes to any plant equipment are involved. Accident precursors or initiating events are not affected in any way as a result of the deletion. Therefore, the deletion will not involve a significant increase in the probability or consequences of an accident previously evaluated.
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l The operation of Nine Mile Point Unit 1. In accordance with the oronosed amendment, will not create the aa==Mtv of a new or different kind of accid =nt from any accident previousiv evaluated, The information requested by license condition C(4)is provided in Attachment E. The results of the analyses demonstrate adequate protection as it relates to GDC-19 dose guidelines under accident conditions without the use of Kl tablets. Deletion of the license condition and the requirement to maintain Kl tablets based on the updated analyses will not affect the ability of Control Room personnel to perform their function. No modifications or changes to any plant equipment are involved. Accident precursors or initiating events are not affected in any way as a result of the deletion. No requirements are changed which could affect plant equipment or operation such that new credible accidents are introduced.
Therefore, the deletion will not create the possibility of a new or different kind of accident from any accident previously evaluated.
The coeration of Nine Mile Point Unit 1. In accordance with the oronosed amendment, will not involve a sionificant reduction in a maroin of safety.
The information requested by license condition C(4)is provided in Attachment E. The results of the analyses demonstrate adequate protection as it relates to GDC-19 dose guidelines under accident conditions without the use of Kl tablets. Deletion of the license condition and the requirement to maintain Kl tablets based on the updated analyses will not affect the ability of Control Room personnel to perform their function. No modifications or changes to any plant equipment are involved. Accident precursors or initiating events are not affected in any way as a result of the deletion. The deletion does not affect any of the principle fission product barriers (i.e., fuel cladding, reactor coolant pressure boundary, or containment) or associated design margins. Therefore, the deletion will not involve a significant reduction in a margin of safety.
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l ATTACHMENT C l
NIAGARA MOHAWK POWER CORPORATION 1
LICENSE NO. DPR-63 DOCKET NO. 50 220 Eligibility for Catenorical Exclusion from Performina an Environmental Assessment 10CFR51.22 provides criteria for, and identification of, licensing and regulatory actions eligible for exclusion from performing an environmental assessment. As described in l
Attachment B, some of the individual doses increased as a result of the updated analyses.
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However, the doses remain within the GDC-19 dose guidelines and are, therefore, acceptable. Offsite releases were not affected. Niagara Mohawk Power Corporation (NMPC) has reviewed the proposed amendment and has determined that it does not involve a significant hazards consideration, there will be no significant change in the types or a significant increase in the amounts of any effluents that may be released offsite, nor will there be any significant increase in individual or cumulative occupational radiation l
exposure. Therefore, the proposed amendment meets the eligibility criteria for categorical l'
exclusion set forth in 10CFR51.22(c)(9) and, pursuant to 10CFR51.22(b), no environmental impact statement or environmental assessment is required to be prepared in connection with this license amendment application.
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ATTACHMENT D NIAGARA MOHAWK POWER CORPORATION LICENSE NO, DPR 63 DOCKET NO. 50 220 Marked-Un Cony of Pronosed Chance to the Current Oneratina License The current version of page 3B of the operating license has been hand marked-up to reflect the proposed change.
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3B-C(4). The licoru,e hall submit an applica ~
forlicense amendm t, including supporting dment application shall l
. analyses evaluations by Dece r 18,1998. This am reliance upon the use o -[
dose guidelines under l
contain proposed methods f compliance with GDC accid t conditions based u system design and po saiumiodide.
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kmendme No.161 WeiA pap
ATTACHMENT E NIAGARA MOHAWK POWER CORPORATION LICENSE NO. DPR-63 DOCKET NO. 50-220 This attachment summarizes the assumptions and results of updated analyses performed consistent with Niagara Mohawk Power Corporation's (NMPC's) March 19,1984 response to NUREG-0737, item Ill.D.3.4, regarding Control Room habitability. The analyses have been reperformed using a different computer code that provided comparable results to that of the previous code. The analyses determined anticipated Control Roam operator radiation exposures from airborne radioactive material and direct radiation resulting from design basis accidents. For a design basis loss of coolant accident, sources of radiation included containment leakage, engineered safety feature leakage outside primary containment, and the leakage through valves in lines that bypass the secondary containment. These sources of radiation contributc to airborne radioactivity levels in the Control Room and direct radiation in the form of shine from the overhead plume, secondary containment, and Control Room emergency ventilation filters. The radiological consequences of a main steam line break were similarly analyzed for airborne radioactivity levels in the Control Room.
The assumptions used to perform the Control Room dose assessment are summarized below.
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Source Terms:
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Loss of Coolant Accident -In accordance witn Regulatory Guide 1.3,100%
of the noble gas activity and 25% of the iodine activity are assumed to be released from the core to the containment atmosphere. 91% of the iodine activity is assumed to be elemental iodine, 5% of the iodine activity is in the form of particulate iodine, and 4% of the iodine activity is in the form of organic iodide. The containment atmosphere source term is used in determining the radiological effects of containment leakage and secondary containment bypass leakage. In accordance with NUREG-0737, item II.B.2, recirculated depressurized cooling water is assumed to contain 50% of the core halogen inventory. The cooling water source term is used in determining the radiological effects of engineered safety feature leakage to the secondary containment.
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Main Steam Line Break -In accordance with Regulatory Guide 1.5, the main steam line is assumed to break, with the reactor at full power, followed by a reactor scram. The main steam isolation valves are conservatively assumed to close in 11 seconds. The Technical Specification (TS) maximum operating time is 10 seconds. The total mass of coolant in the steam line at the time of the break, plus the amount that passes through the valve prior to closure, is assumed to be released. This amounts to 80,900 pounds of coolant water and 26,250 pounds of steam. Of the 80,900 pounds of coolant water, 1 of 3
39,350 pounds flashes to steam. Maximum fission product concentrations are assumed for the release, based on the Nine Mile Point Unit 1 (NMP1) TS l'imit of 9.47 microcuries of totaliodine per gram of water, which was conservatively rounded up to 10 microcuries per gram for the analyses. The i
results indicate that a total of 219 curies are released to the environment, which includes 11.9 curies of I-131,47.3 curies of I-133 and 48.8 curies of g
l noble gases.
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Release Assumptions:
a.
Loss of Coolant Accident - The primary containment leak rate is assumed to be 1.5 percent per day at 35 psig from all sources except miscellaneous valve leakage to the Turbine Building, which is considered separately. This is the TS maximum primary containment leak rate, including all valve leakage.
The Reactor Building smergency ventilation flow rate is 3,200 + 10% cubic feet per minute for 30 minutes, and is then reduced to 1600 + 10% cubic l
feet per minute for the remainder of the 30 days. A 10 second delay is
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assumed for the change over from Reactor Building normal ventilation to emergency ventilation. During this delay, the release is assumed to be l
unfiltered at 70.000 cubic feet per minute. The charcoal filter efficiency for the exhaust flow is conservatively assumed to be 90%. The emergency l
ventilation exhaust flow goes to the stack and is released to the l
environment.
l I-Engineered safety features which recirculate coolant outside the primary containment are very conservatively assumed to leak 750 gallons per hour of l
depressurized coolant into the secondary containment. 10% of the iodine in this leakage is assumed to flash to the secondary containment atmosphere.
l In addition, for conservatism, eight valves in the Turbine Building are assumed to leek primary containment atmosphere at a rate of one standard cubic foot per hour each for the duration of the accident. This release goes to the stack unfiltered. For additional conservatism, no credit is taken for the l
removal of iodine by suppression pool scrubbing, not by plateout or holdup in the piping.
b.
Main Steam Line Break - All noble gases released are included in a ground level cloud. The cloud contains only the iodine contained in the 39,350 pounds of coolant water that flashes to steam. The remaining water rains out in the pipe tunnel and the Turbine Building. The halogens contained in the original volume of steam are neglected since steam to water halogen 4
L concentration ratios are approximately 10. The activity in the ground level cloud is released through the Turbine Building blowout panel, which has an exhaust flow rate of 138 volumes per day. All of the activity is assumed to be released from the blowout panel to the atmosphere within two hours.
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Atmoschose Diffusion Estintatg3:
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Loss of Coolant Accident - The Reguistory Guide 1.145 model for stack j
releases was assumed. The fumigation condition equation was applied from 2 of 3
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i 0 to 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> using a wind speed of 2 meters per second and Stability Class F. This yielded a X/O of 3.12 x 104 seconds per cubic meter. The non-fumigation condition equation was applied from 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> to 30 days using a
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wind speed of 1 meter per second and Stability Class F. This yielded a X/Q of 1.22 x 104 seconds per cubic meter, b.
Main Steam Line Break - The Regulatory Guide 1.145 model for releases through vents or other building pens.uations was assumed, with a wind speed of 1 meter per second and Stability Class F. It was assumed that the lateral and vertical plume spreads were equal to the horizontal (27 meters) and vertical (6.1 meters) dimensions of the blowout panel. The calculated 4
X/O was 1.93 x 10 seconds per cubic meter.
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Protective Features:
The Control Room Air Treatment System is assumed to be automatically actuated at the onset of both accidents, by a loss of coolant accident or main steam line break signal. A 24 second delay before filtration begins is assumed to account for signal response time and valve closure. The outside air flow,2250 cubic feet per minute plus 10%, passes through a 90% efficient charcoal filter, which is conservative.
Unfiltered inlaakage of 30 cubic feet per minute is assumed; 10 cubic feet per minute to account for access / egress and an additional 20 cubic feet per minute to account for inleakage via an unsealed drain.
With the reactor coolant total iodine concentration less than or equal to the TS limit of 9.47 microcuries per gram, the Control Room Air Treatment Systern is not l
required to operate for doses in the Control Room to be less than the GDC-19 dose guidelines for the main steam line break. The doses in Table 1 for the main steam line break conservatively assume that the Control Room Air Treatment System does not operate. With automatic actuation upon receipt of a main steam line break l
signal, the doses will be lower.
Doses due to radioactivity levels in the Control Room itself were calculated using the methodology provided by K. G. Murphy and K. M. Campe, " Nuclear Power Plant Control Room Ventilation Design for Meeting General Design Criterion 19," 13th AEC Air Cleaning Conference, and the computer code DRAGON. The QADMOD computer code was used to calculate exposures due to direct shine from the extemal plume, the Reactor Building, and the Control Room emergency ventilation filters. The results of these calculations are provided in Table 1.
l Standard Review Plan Section 6.4 specifies dose criteria of 5 Rem whole body gamma,30 Rem beta skin and 30 Rem thyroid for Control Room personnel following a design basis l
accident. These criteria ara met for both a loss of coolant accident and a main steam line break accident, using conservative assumptions.
Based on the analyses, the use of potassium iodide is not required as a means to satisfy the GDC-19 requirement that adequate radiation protection be provided to permit access I
t.nd ~ occupancy of the Control Room under accident conditions without personnel receiving l
in excess of 5 Rem whole body gamma, or its equivalent to any part of the body (i.e.,30 Rem thyroid), for the duration of the accident.
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TABLE 1: POST-DESIGN BASIS ACCIDENT CONTROL ROOM DOSES LOCA Type / Source of Radiation Dose (Rem)
Thyroid l
Control Room Atmosphere due to Containment Release 4.80 Control Room Atmosphere due to Engineered Safety Feature Release 1.93 Control Room Atmosphere due to Secondary Containment Bypass Release 10.5 i
TOTAL 22.2 Beta Skin Control Room Atmosphere due to Containment 0.34 Release Control Room Atmosphere due to Engineered Safety 0.007 Feature Release Control Room Atmosphere due to Secondary 0.14 Containmerit Bypass Release TOTAL 0.48 Whole Body Gamma Control Room Atmosphere due to Containment 0.025 Release Control Room Atmosphere due to Engincnted Safety 0.0008 Feature Release Control Room Atmosphere due to Secondary 0.011 Containment Bypass Release External Plume Shine 1.21 Reactor Building Shine 2.82 Control Room Filter Shine 0.003 l
TOTAL 4.07 l
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I TABLE 1: POST-DESIGN BASIS ACCIDENT CONTROL ROOM DOSES (Cont'd) r MSLB' Type / Source of Radiation.
Dose (Rem)
Thyroid 28.6 Beta Skin 0.032 Whole Body Gamma 0.005 s
' Dose values for the main steam line break do not take credit for Control Room Air l
Treatment System filtration.
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