ML19309F240
| ML19309F240 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 03/24/1980 |
| From: | Counsil W NORTHEAST NUCLEAR ENERGY CO. |
| To: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| IEB-80-03, IEB-80-3, NUDOCS 8004290057 | |
| Download: ML19309F240 (2) | |
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L J :Z"O7lTf0"O' March 24,1980 Docket No. 50-245 Mr. Boyce H. Grier, Director Region I Office of Inspection and Enforcement U. S. Nuclear Regulatory Commission 631 Park Avenue King of Prussia, PA 19406
Reference:
(1)
B. H. Grier letter to W. G. Counsil dated February 6,1980, forwarding I&E Bulletin No. 80-03.
Gentl emen:
Millstone Nuclear Power Station, Unit No.1 Response to I&E Bulletin No. 80-03 Reference (1) requested Northeast Nuclear Energy Company (NNECO) conduct an inspection of standard type II, 2-inch tray adsorber cells presently utilized in various plant ventilation systems.
In particular, the NRC Staff requested the following information with regard to this inspection:
(1) The manufacturer and cell design presently in use and the systems containing the cells.
(2)
Examine the rivet spacing securing the cell casing to the perforated screen which may result in separation of the screen and cell housing and adsorber cell or filter housing deformation causing a loss of charcoal and/or channeling.
(3) Describe the manner of the visual inspection performed and determine if the charccal adsorber cells in use, or proposed for use, have the potential for a loss of charcoal incidental to handling, storage or use (as appropriate).
In addition, the NRC Staff requested that this informa-tion be submitted within 45 days of the date of Reference (1).
1... In response to the above items, NNECO provides the following:
ITEM 1 Millstone Unit No. l's only application of charcoal tray adsorber cells is in the Standby Gas Treatment System.
The main plant ventilation exhaust is not filtered.
It has been determined that the problem referenced in this Bulletin does not exist at Millstone Unit No.1.
Millstone Unit No.,' Standby Gas Treatment (SBGT) System consists of two (2) independent trains, each of which is equipped with three (3) charcoal adsorber cell s. Millstone Unit No.1 has twelve (12) cells on site, six (6) in service and six (6) spares.
Ten (10) cells are Mine. Safety Appliance Type II (MSA) and two (2) cells are Charcoal Services, Incorporated Type II.
ITEM 2 The MSA charcoal cells have a perforated screen spot welded at approximately one (1) inch intervals to a stainless steel border, which in turn is spot welded to the filter frame at approximately four (4) inch intervals.
The Charcoal Services' cells are of identical construction with the exception that the screen to border weldments are at approximately three (3). inch intervals.
ITEM 3 The visual inspections consisted of examinations of some of both types of cells.
An examination of three (3) MSA Type.II cells which had been in service for approximately ten years determined that.the screen was tightly affixed to the border and frame, and no evidence of sagging, deformation,.or loss of charcoal was observed.
l These SBGT System filters are tested and inspected every 720 hours0.00833 days <br />0.2 hours <br />0.00119 weeks <br />2.7396e-4 months <br /> of operation.
During 'che ten years of plant operation, no.significant degradation of the charcoal adsorber trays has occurred and in no case. have. they failed.to pass their j
surveillance leak testing.
j We trust you find this information satisfactory to disposition the Reference (1) concerns. We remain available should the Staff require clarification of any of the above information.
Very truly yours, NORTHEAST NUCLEAR ENERGY COMPANY W. G. Counsil Vice President