ML19343C236
| ML19343C236 | |
| Person / Time | |
|---|---|
| Site: | Haddam Neck File:Connecticut Yankee Atomic Power Co icon.png |
| Issue date: | 05/01/1978 |
| From: | Graves R CONNECTICUT YANKEE ATOMIC POWER CO. |
| To: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| CYH-78-128, RO-78-04-1P, RO-78-4-1P, NUDOCS 8103040636 | |
| Download: ML19343C236 (2) | |
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t C,, CONNECTICUT YA N K EE ATOMIC POWER COMPANY HADDAM NECK PLANT A
- 1. BOX 127E. EAST HAMPTONcCONN. 06424
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May 1, 1978 CYH 78-128 pE e
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w U. S. Nuclear Regulatory Commission 2
Region 1 Office of Inspection and Enforcement 631 Park Avenue King of Prussia, Pennsylvania 19406 Attn: Mr. Boyce Grier, Director
Reference:
Facility Operating License No. DPR-61 Docket No. 50-213 Reportable Occurrence 78-04/lP
Dear Mr. Grier:
In accordance with the reporting requirements of Connecticut Yankee Technical Specifications, Section 6.9.2.a. the following preliminary report 78-04/1P concerning the pressurization of the annular poison cavity of the spent fuel storage racks is hereby submitted.
As a result of a test completed on April 28, 1978 on the Connecticut Yankee Spent Fuel Racks, it has been demonstrated that there is significant gas generation and associated pressure buildup in the annular poison cavity of the racks which are presently storing fuel removed during the October 1977 outage. The cause of this gas generation appears to be the result of radiolytic decomposition of moisture in the 84C Flates and/or radiolytic decompositica of the binder material used in the r.naaufacture of the B4C Plates. The effect of this offgassing has been to cause the annular neutron absorber cavity to swell resulting in a reduction in internal cell dimensions as well as reducing the water gap between adjacent cells.
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Preliminary analysis has confirmed there are no imediate safety concerns with the pressurization of the annular poison area. An tr.vestigation is being cenducted to correct this probicm.
A follow-up report will be forwarded within fourteen (14) days.
Very truly yours, f
AW Richard H. Graves
~ Station Superintendent JHF:RHG/jhb cc: Office of Management Information and Program Control, Wash., D. C.
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