ML20003A261
| ML20003A261 | |
| Person / Time | |
|---|---|
| Site: | Maine Yankee |
| Issue date: | 01/16/1981 |
| From: | Johnson W Maine Yankee |
| To: | Eisenhut D Office of Nuclear Reactor Regulation |
| References | |
| RTR-NUREG-0737, RTR-NUREG-737, TASK-2.F.1, TASK-3.D.3.3, TASK-TM FMY-81-10, NUDOCS 8102030268 | |
| Download: ML20003A261 (4) | |
Text
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' ERIIE HRilHEE AlumlCPOWER COMPAmt *
,s,, w onces,en noAo h
ENGINEERING OFFICE FRAMINGH AM, M ASSACHUSETTS 017o1 U
617 872-8100 II 2.C.2.1 January 16, 1981 FMY 81-10 United States Nuclear Regulatory Commission Washington, D. C.
20555 Attention:
Darrell G. Eisenhut, Director Division of Licensing
References:
(a)
License No. DPR-36 (Docket No. 50-309)
(b)
USNRC Letter, D. G. Eisenhut to All Licensees of Operating Plants, dated October 31, 1980 (c) MYAPC Letter, J. B. Randazza to D. G. Eisenhut, da ted December 15, 1980 Sub je c t :
Deviations From Specific Post-TMI Requirements (NUREG-0737)
Dear Sir:
Reference (b) transmitted all TMI-related items approved for implementation by the Commission as of October 31, 1980.
Reference (c) provided a tabulation by item of the implementation schedules specified in of Reference (b), and our specific plans addressing each one.
Your letter, Reference (b) suggested that any deviation of staff positions / clarifications be discussed in subsequent letter (s).
The attachments to this letter detail deviations to certain items listed in Re ference (b).
Please recognize that actions are being taken on each item, although we have identified the need for devia tions.
We trust the information contained in the attachment adequately documents
)
Maine Yankee 's reasons for taking exception to certain items given in Reference (b) and our intended actions.
If additional clarification of our position is necessary, please contact us as soon as possible in order to allow a timely resolution of any difficulties.
Very truly yours, c
c.
MAINE YANKEE ATOMIC POWER COMPANY
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a-W. P. dohnson
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Vice President O 1 O ' '? Ch
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.i United States Nuclear Regulatory Com:ission January 16, 1981 Att: Mr.-D. G. Eisenhut, Director Page 2
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i C0K40NWEALTH OF MASSACHUSETTS)
)ss COUNTY OF WORCESTER
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Ther. personally appeared before se, W.P. Johnson, who, being duly sworn, did state that he is a Vice President of Maine Yankee Atocic Power Compa.y, that he is duly authorized to execute and file the foregoing request in the name and on the behalf of Ma'ne Yankee f Mcic Power Company, and tbe*
he statements therein are true to the best of his knowledge and beliet Robert H. Groce
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Notary Public My Commission Expires September 14, 1984:
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Attachment II.F.1. :
Noble Gas Effluent Monitor Table II.F.1-1 (High Range Noble Gas Effluent Monitors) states that the high range noble gas monitor should have a continuous and recording display in equivalent Xe-133 concentration orflCi/cc of actual noble gases.
However, clarification (4)(b) requires consideration of the radionuclide spectrum distribution as a function of time after shutdown.
Because of these conflicting requirements, we have chosen to have the instrument readout in dose rate (i.e., mr/hr).
Conversion to equivalent Xe-133 concentration and/or actual noble gas concentration is accomplished by procedure.
NUREG 0737 requires final design details be available for review by January 1, 1981. However, because work is still being performed by the vendor and Yankee NSD, final design details will not be available until May 1, 1981.
II.F.1 : Sampling and Analysis of Plant Effluents The design basis shielding envelope used for the stack sampling medium assumes the charcoal is exposed to 100[lCi/cc (I-131) for 30 minutes, which based on the stack sample flow rate (5 cfm) results in 425 C1 of I-131 on the charcoal sample medium.
Aconcentrationof100[lCi/ccintheprimaryventstackisonlypossible if you assume:
an unlikely total loss of coolant and subsequent core melt,
- a. loss of reactor vessel integrity, all I-131 fission products are released as a gas within. the containment, failure of the normally closed containment purge isolation valves to close should they be open during operation.
the absence of the charcoal filter units in the purge lines.
Maine Yankee believes a LOCA combined with a core melt and loss of vessel integrity is an incredible event, and beyond the design basis of the plant. We are confident that the containment isolation system and charcoal filter units will function as designed and thereby reduce actual iodine activity to extremely low levels.
Furthermore, as you no doubt already know the iodine source term has recently came under close scrutiny, and design bases accident assemptions are suspected of being inappropriately conservative.1 Based on the above information, we seriously question the 100 [lCi/cc source term at the stack sampler, and propose no change to the physical arrangements of the sample station.
The plant has the capability 'to continuously sample gaseous effluents for post-accident release of 1 Commission Meeting on Iodine Release From Accidents and Estimates of Consequences of Nc01 ear Accidents on Tuesday, November 18, 1980.
3 radioactive iodines and particulates. Onsite laboratory facilities are provided to measure and/or analyze the samples.
Detailed procedures have been developed concerning the handling and analysis of these samples as well as provisions to minimize noble gas interference.
In the unlikely event of a high level halogen release from the plant there exists other more reliable and reasoncble methods for a quantitative assessment of the effluent release; i.e.,
direct measurement St the source, or offsite sampling for I-131.
III.D.3 3 Improved Inplant Iodine Instrumentation Under Accinent '
Conditions The clarification for this item requires the use of portable instruments using sample media that will collect iodine selectively over xenon (e.g.,
silver zeolite).
Furthermore, the clarification goes on to state that the sample should be purged of any entrapped noble gases using nitrogen gas or clean air free of noble gases prior to analysis. We presume this action will remove noble gases from the cartridge free air vrlume.
Maine Yankee will have a sapply of silver loaded silica gel at the plant for use in the event of an emergency..since this medium has been -shown to be iodine-specific.
Additionally, we recognize that compressed (bottled) air or nitrogen can be used to purge entrapped noble gases from charcoal; therefore we intend to use activated charcoal as an alternative to the silver loaded silica gel when appropriate.
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