ML19340B324
| ML19340B324 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 06/10/1976 |
| From: | Clark R Office of Nuclear Reactor Regulation |
| To: | Grimes B Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8010210872 | |
| Download: ML19340B324 (2) | |
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27 Brian K. Gtimes, Chief Environmental Evaluation Branch, DOR 7,
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L. Barrett, Section Leader, Environmental Evaluation Branch, D0R i
TRIP REPORT - DRESDEN UNIT NO. 1, DOCKET #50-10
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On May 25 and 26, 1976, I visited Dresden Unit No. 1 to observe'the 55f decontamination of the Dresden Unit No. 1 test loop. Decontamination of the test loop is one of several R (. D programs being conducted by Consnon-wealth Edison, Dow Chemical And General Electric to obtain data and
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experience in preparation for decontamination of the Dresden Unit No. 1 primary system.
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In 1974, Cc.amonwealth Edison advised us of their proposed plans to
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decontaminate Dresden Unit No.1 and submitted the preliminary results of fffffi the test programs and investigations which they had been conducting since
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S 1972. In response to staff questions, the licensee supplemented their
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original submittal on April 16, 1975. The staff approved the decontamina-sgs...
tion of Dresden Unit No.1 on December 9,1975. The decontamination of i+: 1::E?
the primary system is scheduled for March 1978, the estimated completion date for construction of a large, new radwaste processing facility (180' x 130', 3 stories high). The decontamination program is estbnated
._...2 to cost $36 million, with ERDA expected to pay about $8 million.
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The corrosion test loop currently being decontaminated was originally owned by the AEC and operat 3 under contract by GE to obtain data on stress
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corrosion. It was originally connected to the Dresden Unit No. 1 system in 1967. The system consists of three vessels containing corrosion test specimens, spool pieces containing specimens from other reactors, pu: ps, a heat exchanger, and associated valves, piping and instrumentaion. The 52-system so that none of the deccataminating solvent or rinse solutions N" :
corrosion test loop is now physically separated from the Dresden Unit No.1
"~=1 could leak into the Dresden primary system. Radiation 1cvels at the surface EE of the piping and components in the test loop were as high as 20 R/hr.
5:g The decontar.inating solvent being tested i i the corrosion test loop is s
a proprietary solvent developed by DOW Chemical Co. and designated as
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The general plan was to hydrotest the system, introduce the solvent, M:
0 bring the loop up to temperature (250 to 255 F) and pressure, circulate the solvent for 100 hours0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br />, drain and flush with demineralized water until
?2 all traces of the solvent are removed. DOW estimates that 2 or 3 complete 5;[
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flushes will accomplish complete removal of the tolvent. According to the E
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$;2,=J schedule, the solvent was to have been introduced on May 21, 1976. I had expected to be present wille the solvent was being drained to observe p~== _
the effectiveness of the decontamination and rinsing.
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JUN 10 Ed 2-However, the hydrotesta disclosed a number of leaks in the system, part-g; icularly in the many old thermocouple penetrations in the pressure vessels.
qg Wheb it was ev& dent that the hot hydrotest on May 26, 1975 disclosed
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additional leaks, I returned to the office.
(A successful hot hydro was'
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finally completed on June 3,1976 and solvent was introduced on June 4,1976.)
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One of the problems associated with decontamination is the large volume.
of liquid waste from the solvent and water rinses. As part of the test programs, DOW will be solidifying the concentrated waste solution with their newly developed p&lymer process. This is scheduled for mid_-July 1976.
Richard J. Clark
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Environmental Evaluation Branch
u-Division of Operating Reactors 11
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B. Rusche
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E. Case R. Heineman H. Denton R. Boyd DISTRIBUTION:
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