ML19256D328
| ML19256D328 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 12/01/1970 |
| From: | Crocker L US ATOMIC ENERGY COMMISSION (AEC) |
| To: | Deyoung R US ATOMIC ENERGY COMMISSION (AEC) |
| References | |
| NUDOCS 7910170834 | |
| Download: ML19256D328 (3) | |
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UNITED STATES f '* J q ;
AiOMIC ENERGY COMMISSION
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December 1,1970 R. C. DeYoung, Assistant Director for Pressurized Water React:cs, CRL THRU:
C. G. Long, Chief, PWR Project Branch No. 2, DRL hi'f {
MEETING WITH METROPOLITAN EDISON COMPANY ON THREE MILE ISLAND UNI" 1 OPERATING LICENSE (DOCKET No. 50-2S9)
A meeting was held at Bethesda on November 24, 1970 with represe.atatives of the Metropolitan Edi. son Company and its contractors to diccus a of draf t questions, and to disclose the results of the DRL evaluation set of the proposed use of so lium thiosulphate.
A list of attendees is enclosed.
A major portion of the meeting was devoted to discussions regarding the use of sodium thiosulphate as a spray additive. We pointed out that we would require a pH monitoring system designed to operate under post-LOCA conditions, and the capability of adding additional sodium hydroxide as necessary to maintain a solution pH >8.0 0.2.
We stressed the possible corrosion problems caused by the spray solution and indicated that the total weight of exposed aluminum should not exceed 500 pounds, and that the total quantity of exposed copper uhould be as low as practicable. Finally, we stated our concern regarding the long term storage stability of the sodium thiosulphate solution and indicated that either additional R&D would be required to better define this storage stability, or that a frecuent inspection schedule would be required.
Our stated position regarding the effectiveness of sodium thiosulphate was that its use would increase the removal cons tant for elemental iodine by about 30% over that for sodium hydroxide alone, and that we would grant credit for removal of organic iodides up to a maximum decontamination factor of 8-10 in the long term.
Representatives of the applicant pointed out that they do not feel we are giving full credit for the use of the thiosulphate.
B&W personnel presented a summary briefing of material contained in their topical BAW-10022 (not yet reviewed by us due to its recent availa-bility).
Among other things, they feel that hypoiadous ac d (HOI) 4 accounts for approximately one-half of what previously has been thought to be organic iodides. Further, they contend thst HOI would not be expected to form in the presence of the thiosulphate solution. Their calculations, using the SPRAY-2 code, predict an overall dose reduction factor for the iodine of 22.8, with a confidence lavel of 97% that the calculation is conservative.
1454 286 M
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R. C. DeYoung 2
December 1,1970 We furnished samples of our dose calculations to B&W.
It was agreed that they would review our assumptions and calculations while we reviewed their data and that we would have another meeting later to see if we can give any additional credit for the thiosulphate spray.
Our calculations indicate a (non-acceptable) 2-hour thyroid dose at the exclusion area boundary of 321 Rem, granting credit for the thiosulphate spray. We s:ated our desire to obtain calculated dose values substantially below the Part 100 guidelines and we indicated a number of design changes which could reduce the dose.
The alternatives mentioned were a reduction in the leak rate, increasing the spray system flow rate, installation of HEPA and charcoal filters, and evidence of better meteorology.
The draft questions were discussed with the applicant's representatives.
Acceptable answers to some of the questions were obtained during the meeting, while others are expected to be covered by submittals now being prepared by the applicant. A number of the questions will appear on the formal question list.
We pointed out that if B&W does not submit their topical on ECCS until 1 March, there may be a problem 1: going before the ACRS at the April meeting.
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m ne,&r L. Crocker PWR Project Branch No. 2 Division of Reactor Licensing Distribution:
Docket RWKlecker DRL Reading Branch Reading PAMorris FSchroeder 54 287 TRWils on RS3cyd RCDeYoung DShovholt EGCase, DRS RRMac cary Compliance ORL 3 ranch Chiefs DRS 3 ranch Chiefs Dross LCrocker G3urley TNovak FKaras
a LIST OF ATTENDEES MEETING WITH METROPOLITA:; EDISON COMPA.W RE THREE MILE ISLAND UNIT 1
':0VE'!BER 24, 1970 Me -Ed G. F. Bierman D. H. Reppert Pickard Love & Associates K. Woodard Gilbert Associates C. H. Bitting F. Symons L. B. Myers B&W E. Ward J. M. Cutchin D. A. Nitti R. W.
Prados R.
B.
Bo rs on J. F. Vallay 1454 288
. S. Delicate AEC/DRL C. G. Long (part time)
P. Howe D. F. Ross G. Burley T. Novak L. P. Crccker