ML20040E273
| ML20040E273 | |
| Person / Time | |
|---|---|
| Site: | 05000000 |
| Issue date: | 03/04/1982 |
| From: | NRC OFFICE OF INSPECTION & ENFORCEMENT (IE) |
| To: | |
| References | |
| IEIN-82-03, IEIN-82-3, NUDOCS 8202040111 | |
| Download: ML20040E273 (3) | |
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6835 Accession No.:
8202040111 IN 82-03 UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, DC 20555 March 4, 1982 IE INFORMATION NOTICE NO. 82-03:
ENVIRONMENTAL TESTS OF ELECTRICAL TERMINAL BLOCKS Discussion:
This information notice pertains to the results of NRC sponsored research con-ducted on electrical terminal blocks (type CF-1518 and CR 29605 General Electric and type FWM States).
These may be typical of those utilized in many nuclear power plants.
The research program was conducted at Sandia Laboratories in Albuquerque, New Mexico, and consisted of approximately 600 individual tests made on enclosed and open terminal blocks of the type used at TMI-2.
The terminal blocks were subjected to 100% humidity conditions at 186 F which were the conditions experienced by some terminal blocks during the TMI-2 accident.
(Note:
To date, there has been no evidence of terminal block failure at TMI-2 during the TMI-2 accident or after).
No tests at other LOCA conditions were conducted.
Terminal block performance ander the test conditions was measured by monitoring electrical terminal to ground leakage current with terminal to ground voltages of 120, 240, and 480 volts.
Some terminal blocks were installed in metal enclosures with a 6 mm pressure relief hole.
These metal enclosures were mounted in a horizontal plane during the tests.
Some tests were made by simulating chemical spray and various contaminants that may be found on terminal blocks and could result in electrolytic leakage paths in nuclear power plants.
The results of these tests indicated instances of leakage currents when blocks were directly expcsed to chemicals and steam.
The NRC recognizes that the use of properly designed terminal blocks inside containment is an option of the applicant.
NRC requires qualification of all electrical connections, cable splices as well as terminal blocks, for accident conditions.
It is recognized that cleanliness of terminations and terminal blocks in circuits important to safety is of concert to designers, constructors, and licensees.
The cleanliness aspects are addressed in Appendix B of 10 CFR 50.
These regula-tions require the licensee to establish appropriate procedures based upon manu-facturers' and constructors' recommendations, operating experience, and specific component characteristics to assure that equipment is stored, installed, and maintained in an acceptable state.
To this end, IEEE-336, ANS 3.2, and ANSI 45.2.3 Standards and NRC Regulatory Guide 1.39 are being used by designers, constructors, and operators of power plants which address the installation, cleanliness, and on going maintenance of Class 1E electrical components, including terminal blocks.
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IN 82-03 March 4, 1982 Page 2 of 2 In view of the above, licensees are reminded that the plant preventive maintenance program in use at their facilites should assure (1) proper operation of all essential components is achieved throughout the life of the plant; and (2) that periodic inspection of those terminations and terminal blocks for cleanliness and installation integrity is performed following any maintenance activity affecting them.
The Office of Inspection and Enforcement has general inspection procedures which are used by inspectors to monitor compliance with the above Standards, Guides, and recommendations.
Terminal blocks are specifically identified as an example of a component which must be inspected for cleanliness during construction of the power plant.
No specific action or response is required at this time.
If you have any questions regarding this matter, please contact the Regional Administrator of the appropriate NRC Regional Office.
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IE Information Notice No. 82-01, Revision 1 February 26, 1982 LISTING OF RECENTLY ISSUED IE INFORMATION NOTICES Information Subject Date Issued To Notice No.
Issued 81-37 Unnecessary Radiation 12/15/81 All byproduct material Exposure to.Public &
licensees Workers during Events Involving Thickness &
Level Measuring Devices 81-38 Potentially Significant 12/17/81 All power reactor facilities Equipment Failures with an Operating License Resulting from Contam-(0L) or Construction Permit ination of (CP)
Air-0perated Systems 81-39 EPA Crosscheck Program -
12/23/81 All power reactor facilities Low Level Radiciodine in with an Operating L"ense Water Test Program (0L) or Construction Permit (CP), and Priority I material licensees 82-01 Auxiliary Feedwater Pump 1/25/82 All power reactor facilities Lockout Resulting from with an Operating License Westinghouse W-2 Switch (OL) or Construction Permit Circuit Modification (CP) 80-32 Clarification of Certain 2/12/82 All fuel facility, materials, Rev. 1 Requirements for Exclusive-and Part 50 licensees Use Shipments of Radioactive Materials 82-01 Auxiliary Feedwater Pump 2/26/82 All power reactor facilities Rev. 1 Lockout Resulting from with an Operating License Westinghouse W-2 Switch (0L) or Construction Permit Circuit Modification (CP) 82-03 ENVIRONMENTAL TESTS OF 3/4/82 All power reactor facilities ELECTRICAL TERMINAL BLOCKS
.with an Operating License (0L) or Construction Permit (CP)
Enclosure