ML19322A257
| ML19322A257 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 02/05/1979 |
| From: | Reid R Office of Nuclear Reactor Regulation |
| To: | Herbein J METROPOLITAN EDISON CO. |
| References | |
| NUDOCS 7903060662 | |
| Download: ML19322A257 (4) | |
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UNITED STATES
[s NUCLEAR 'IEGULATORY COMMISSION
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WASHINGTON D.C.20555
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February 5,1979
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., i Docket No. 50-289 0
Mr. J. G. Herbein Vi.cc President Metropolitan Edison Company P. O. Box 542 Reading, Pennsylvarria 19640 -
Dear Mr. Herbein:
By letter dated April 20, 1977, you proyided a detailed evaluation of the potential consequences of a postulated fuel handling accident inside containment at the Three Mile Island Nuclear Station, Unit No.1 (TMI-1). We have reviewed your analysis and have determined that, where guidance is provided, the assumptions used for the analysis are comparable with the guidance of Regulatory Guide 1.25 and justified by the quality of the equipment on which you rely.
In our analys's, however,,,gehave3usedalargeratmogphericdispersionfactor(X/Q=
1.1 x 10 sec/m vs your 6.1 x 10- ) and have only given credit for conditions required by the TMI-1 Technical Specifications. Using these assumptions we find that the dose from this postulated accident is approximately 300 rem to the thyroid.
For us to conclude that the potential consequences of this postulated accident are appropriately within the guidelines of 10 CFR Part 100 (i.e., less than 100 rem thyroid), we have had to also use your assump-tion of operation of the purge exhaust filter system or to assume the minimum delay between shutdown and initiation of refueling is 400 hours0.00463 days <br />0.111 hours <br />6.613757e-4 weeks <br />1.522e-4 months <br />.
Either assumption reduces the calculated consequences of the accident by about a factor of three..Neither assumption, however, is based on requirements presently in the TMI-l Technical Specifications.
To assure that the consequences of this postulated accident are bounded we consider it appropriate to have one or the other of the above assump-tions required by the Technical Specifications. Therefore, we request that (1) you propose Technical Specifications requiring use of the purge exhaust filter system which you assume in your analysis (utilizing the model Technical Specifications in Enclosure 1) or (2) you either confirm that this minimum delay time of 400 hours0.00463 days <br />0.111 hours <br />6.613757e-4 weeks <br />1.522e-4 months <br /> is shorter than the time needed to begin refueling or you propose a Technical Specification establishing a minimum delay time of 400 hours0.00463 days <br />0.111 hours <br />6.613757e-4 weeks <br />1.522e-4 months <br /> before beginning refueling. Confirming the delay time is shorter than the time needed to begin refueling wfil 7903066 Mo2
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Mr. J. G. Herbein require, as a minimum, listing the mandatory steps. betwes.. shut-down and the initiation of refueling and the minimum time required for each step.
If you elect to request a change in the facility Technical Speciff-cations, you should submit such a request, together with the approp-riate fee, within 60 days of receipt of this letter.
Sincerely.
Afs.' - ' ? i -fN; Robert W. Reid, Chief Operati.ng Reactors Branch #4 Division of Operating Reactors
Enclosure:
Model Technical Specifications cc w/ enclosure:
See next page e
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!!etropolitan Edison Company CC:
G. F. Trowbridge, Esquire Shaw, Pittnan, Potts & Trowbridge 1800 il Street, N.W.
Washington, D.C.
20036 GPU Service Corporation Richard W. Heward, Project Manager Mr. E. G. Wallace, Licensing Manager 260 Cherry Hill Road Parsippany, New Jersey 07054 Pennsylvania Electric Company" Mr. R. W. Conrad Vice President, Generation 1001 Broad Street Johnstown, Pennsylvania 15907 fliss !!ary V. Southard, Chairman Citizens for a Safe Environment P. O. Box 405 Harrisburg, Pennsylvania 17108 Mr. Robert B. Borsum Sabcock & Wilcox Nuclear Power Generation Division Suite 420, 7735 Old Georget'own Road Bethesda, !!aryland 20014 Government Publications Section State Library of Pennsylvania Box 1601 (Education Building)
Harrisburg, Pennsylvania 17126 e
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REFUELI!:G OPERATIONS CONTAIfMENT BUILDING PURGE. FILTRATION SYSTEM LIMITIf!G CONDITION FOR OPERATION The Containment Building Purge Filtration Systen shall be exhausting through HEPA filters and charecal adsorbers.
- APPLICABILITY: WHEN IRPADIATED FUEL IS BEING HANDLED IN THE CONTAIlC4ENT IRRADIATED FUEL HAS DECAYED LESS THAN l(400) HOURS ACTIO!!: With the requiremenU of the above specification not satisfied, suspend all operattoc involving movement of fuel within the containment until the system is restored to operating status.
SURVEILLANCE PEQUIREMENTS The above required Containment Building Purge Filtration System shall be demon-strated OPERABLE:
At least once per 18 months and (1) after each complete or partial re-a.
placement of a HEPA filter or charcoal adsorber bank, or (2) after any structural maintenance on the HEPA filter or charcoal adsorber housing which could effect system operation:
1.
Verifying that the charcoal adsorbers remove 1 g% of a halogena;ed 9
hydrocarbon refrigerant test gas when they are tested in-place while 1
operating the ventilation system at a flow rate of cfm t 10%.
2.
Verifying that the HEPA filter banks remove t 99% of the DOP when they are tested in-place while operating the ventilation system at a flow rate of cfm i 10%.
, b. 'At least once per 18 months and after:every 1440 hours0.0167 days <br />0.4 hours <br />0.00238 weeks <br />5.4792e-4 months <br /> of system operation, subject a representative sample of carbon from the charcoal adsorbars to a laboratory analysts and. verify within 31 days a removal efficiency of a 75% for radioactive methyl 1odine at an air flow velocity of 0.67 ft/see t 20% per test 5.5 in Table 2 of Regulatory Guide 1.52, July 1976.
Basts: The Ifmitations on the Containment Butiding Purge Filtration System ensure that all radioactive material released frem an irradiated fuel assem51y will be ffitered through the HEPA fil-ters and a charcoal adsor5er prior to discharge to the atmosphere.
The OPERABILITY cf this system and the resulting iodine removal capacity are consistent with the assumptions of the accident analyses. The representative carbon sample will be two inches in diameter with a length equal to the thickness of the bed.
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