ML20237L178
| ML20237L178 | |
| Person / Time | |
|---|---|
| Site: | Seabrook  |
| Issue date: | 03/20/1986 |
| From: | Jamison J, Stoetzel G Battelle Memorial Institute, PACIFIC NORTHWEST NATION |
| To: | Hawxhurst J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| Shared Package | |
| ML20237L120 | List: |
| References | |
| FOIA-87-346 NUDOCS 8709080255 | |
| Download: ML20237L178 (2) | |
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serch 20. 1986 I'aciht Northwest Laboratories P.O. Box 999 Mr. James W. Hawxhurst Richland. Washington b.5 A. 99352 U.S. Nuclear Regulatory Commission Telephone g509i 375-3782 Region 1 Tele = 15.w4 631 Park Ave.
King of Prussia, PA 19406
Dear Jim:
SEABROOK DOSE ASSESSMENT SCENARIOS' During the Seabrook exercise George Wehman identified an apparent weakness in the licensee's dose assessment program.
It appears that their program is limited in that it can only handle LOCAs with a monitored release out the plant vent stack.
Four dose assessment scenarios were generated to compare against the licensee's results for a variety of release pathways.
Perhaps they can be used as a basis to determine the adequacy of the licensee's program during the continuation of the appraisal next week.
Copies of the four scenarios are attached.
Calculations were performed using IRDAM.
A brief description of each scenario is provided below:
Scenario 1 (Primary Vent Stack Release) - A ground-level release through the plant's primary vent stack was assumed.
A unit release of 1 C1/sec with an iodine to noble gas ratio of 0.001 after filtration was used in the calculation.
Other key paran.eters used can be. found on the attached print-outs.
Scenario 2 (Primary Vent Stack Release) - This scenario is similar to Scenario 1 except a 50-m release height was assumed.
Scenario 3 (Containment Leakaoe) - This scenario assumes that 0.1% of contain-ment is released per day for a fuel melt accident.
The release is at ground-level with an iodine to noble gas ratio of 0.001.
Scenario 4 (Coolant Leakaae) - This scenario assumes an accident where reactor coolant is leaking outside of containment at a rate of 1.000 gpm.
Again a ground-level release with an iodine to noble gas ratio of 0.001 was used.
Per your phone conversation with Greg Stoetzel, there are other types of acci-dents not directly involving the reactor system which could generete significant offsite doses. One is a fuel handling accident. provides infor-.
mation on a fuel handling accident from a recent exercise scenario.
The source' term for such an accident is dependent on the age of the affected fuel.
A waste gas decay tank rupture accident could also generate significant offsite 87090B0255 G70902 PDR FOIA 4
CONNOR87-346 PDR 1
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Mr. James 1l. Hawsburst l
March 20, 1986 i
Page 2 i
l doses.
The licensee should be able to estimate a source term and calculate l
off site doses for both these accident types.
If you have any questions on this information, please contact Greg Stoetzel on (509) 375-2781.
Sincerely, R
J. D. Jamison G. A. Stoetzel l
Technical leader Senior Research Scientist l
Health Physics Technology Section Health Physics Technology Section i
HEALTH PHYSICS DEPARTMENT HEALTH PHYSICS DEPARTMENT JDJ/ GAS:mae cc:
DB Matthews I
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