ML19224A727
| ML19224A727 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 01/25/1979 |
| From: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | Sniezek J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE) |
| References | |
| NUDOCS 7905300122 | |
| Download: ML19224A727 (3) | |
Text
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I MEMORANDUM FOR:
James H. Sniezek, Director, Division of Fuel Facility and Materials Safety Inspection, IE:HQ FROM:
Boyce H. Grier, Director, Region I PROPOSED IE. CIRCULAR:
INTERCONNECTION OF CONTAMINATED SUBJELT:
SYSTEMS WITii SERVICE AIR SYSTEMS USED AS THE SOURCE OF BREATHING AIR (AITS F18308H3)
Enclosed is a proposed IE Circular regarding interconnections of Our contaminated systems with the plant source of breathing air.
inquiries to 20 power reactor facilities in Region I have indicated that three of these facilities' service air systems, which are used as a source of breathing air, have some physical interconnection with a contaminated system. Two other facilities have indicated that the possibility of such an interconnection exists.
Consequently, it is reconnended that this Circular be issued to all power reactor licensees, permit holders, test reactors, and fuel cycle facilities.
e Bo
. 'Grier Director
Enclosure:
Proposed IE Circular CONTACT:
D. R. Neely (488-5212)
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790530012;t Ch 167 072
DRAFT U. S. Nuclear Regulatory Commission Office of Inspection and Enforcement Washington, D. C.
Proposed Circular Date Page 1 of 2 i
i INTERCONNECTION OF CONTAMINATED SYSTEMS WITH SERVICE AIR SYSTEMS USED AS THE SOURCE OF BREATHING AIR DESCRIPTION OF CIRCUMSTANCES:
This circular describes an event which occurred at a nuclear power facility; however, the generic implications may be applicable to test reactors and fuel cycle facilities.
On October 4,1978, the Philadelphia Electric Company (PECO) reported that, on two occasions at Unit 2, contamination had leaked from the radwaste system to a system used to provide the plant source of breathing air. The leakage occurred by means of an interconnection of the radwaste system with the plant breathing air source.
PECO has established that no individuals were subject to contaminated breathing air as a result of this leakage.
One of the functions of the service air system at Peach Bottom is to provide a source of breathing air for personnel using supplied air respiratory protective equipment.
Peach Bottom also uses the service air system to provide a source of compressed air by means of an inter-connection to the radwaste system during the backwash cycle of the demineralizer filter element.
The compressed air provides the motive force for reverse water flow through the filter element and was being used to perform this function at the time the two incidents occurred.
Liquid from the radwaste system leaked past a check valve and a process valve.
PECO datermined by analysis of liquid samples that contamination had ler.ked 'nto the service air system. Valves in the leakage path were subsequently dismantled and examined.
The examinations revealed the presence of dirt deposits in the check valve and air operated ball valve.
PECO attributes the specific cause of the leakage to these dirt deposits which prevented the proper seating of the valves.
NRC contacts with other cperating power reactors have indicated that some of these facilities also use service air as a source of breathing air.
In several cases, the service. air system is physically inter-connected to other systems which carry radioactive material and relies on valves or other barriers to preve ~.t contamination of the plant source of breathing air.
167 073
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i Proposed Circular
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Date l
Page 2 of 2 i
l NUREG-0041, " Manual of Respiratory Protection Against Airborne Radioactive Haterials," which supplements the stipulations of Regulatory Guide 8.15, I
states in Section 9.8, "A separate breathing air supply and distribution I
system shall be used.
The ordinary plant supply of compressed air in any building shall not be used for breathing purposes...unless it has been specially modified and properly adapted for such use and specifically approved for this purpose by the qualified person supervising the respiratory protective equipment program".
It is recommended that you review your systems and as-built (or design) drawings, identify all interconnections between contaminated and non-cc.itaminated systems used to provide a source of breathing air, and review the interconnection design to assure that adequate separation has been provided.
Operating procedures which could lead to inadvertent contamination of the plant breathing air source should be reviewed and administrative controls provided to prevent contamination of the plant breathing air source.
No written response to this Circular is required.
Your review of this matter to determine its applicability to your facility and any correc-I tive and preventive actions taken or planned, as appropriate, will be reviewed during a subsequent NRC inspection.
If you desire additional information regarding this matter, contact the Director of the appro-priate NRC Regional Office.
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167 074
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