ML18139B775
| ML18139B775 | |
| Person / Time | |
|---|---|
| Site: | Surry  |
| Issue date: | 02/24/1982 |
| From: | Leasburg R VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | Harold Denton, Varga S Office of Nuclear Reactor Regulation |
| References | |
| REF-SSINS-6820 329A, IEB-79-01B, IEB-79-1B, NUDOCS 8203050245 | |
| Download: ML18139B775 (2) | |
Text
e VIRGINIA ELECTRIC AND POWER COMPANY RICHMOND~ VIRGINIA 23261 R.H.LEASBUHO VICE PRESIDENT NUCLEAR OPERATIONS February 24, 1982 Mr. Harold R. Denton, Director Office of Nuclear Reactor Regulation Attn:
Mr. Steven A. Varga, Chief Operating Reactors Branch No. 1 Division of Licensing U. S. Nuclear Regulatory Commission Washington, D. C.
20555 Gentlemen:
Serial No. 329A NO/RGS:lms Docket No. 50-281 License No. DPR-37 REVISION TO RESPONSE TO SAFETY EVALUATION REPORT FOR ENVIRONMENTAL QUALIFICATION OF SAFETY RELATED ELECTRICAL EQUIPMENT CABLE TERMINATIONS AND SPLICES I.E. BULLETIN 79-0lB 90-DAY REVIEW SURRY POWER STATION UNIT 2 This letter provides a rev1s1on to Vepco's response to the Safety Evaluation Report (SER) submitted to you on August 24, 1981 for Surry Unit 2.
In our SER response we indicated that, "As part of the field verification
- program, all terminal blocks in safety related circuits located inside containment were replaced with qualified Raychem Splices (WCSF-N)."
During a January 1982 meeting with our architect-engineer on the environmental qualifi-cation modification project, we were informed that apparently a number of cable terminations had not been modified during the December 1981 Refueling Outage.
In response to this information, we made a full-power Unit 2 Containment entry to check sample circuits and conducted a search of our documentation files.
As a result of our review, it appears that a large percentage of the subject cable terminations were not replaced with the qualified Raychem Splices.
In view of the above situation, it is our intent to modify a significant number of the cable terminations in the Unit 2 Containment Building with the Raychem Splice material during the upcoming May 1982 Spring Maintenance Outage on Unit 2.
The remaining cable terminations shall be modified with the quali-fied mater.ial during the Fall 1982 Maintenance Outage.
It is my understanding that the terminal blocks and splices that exist in the plant have been specified and installed in strict accordance with established power industry practices.
We have identified three (3) types of terminal blocks that are installed in the Unit 2 Containment:
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e VIRGINIA ELECTRIC AND POWER COMPANY TO 2
- 1.
General Electric terminal blocks -
The GE EB 25 AW terminal blocks are made of phenolic material which is not affected by less than 10 7 Rads (NUREG C12-1682, SANDB0-1957 Rv, page 56, Section C, Para. 1).
The blocks were chemically sprayed with boric acid concentration of 2600 ppm at an average temperature of 286°F for about 25 hours2.893519e-4 days <br />0.00694 hours <br />4.133598e-5 weeks <br />9.5125e-6 months <br /> (FIRL-DOCK 50-213).
These terminal blocks have been irradiated up to 108 Rads by Wyle Labs and presently are under test by Burntly for more severe LOCA temperature, pressure and chemical spray profiles for 30 days.
- 2.
Buchanan terminal blocks -
The block phenolic material is typical of acceptable industrial quality terminal blocks.
These terminal blocks are similar is quality to the GE EB type block.
In addition, they are protected by NEMA enclosures.
The environmental conditions at the block location outside the cranewell are relatively mild, particularly the 40 year plus LOCA gamma dose of only 7.4 Megarads.
- 3.
Ceramic terminal blocks -
The ceramic type terminal blocks are mounted in junction boxes serving the hydrogen re combiners.
The terminal blocks are installed in NEMA enclosures which provides significant protection against moisture and chemical spray.
The ceramic material provides radiation resistance and evidence 0£ high-temperature suitability.
On the basis of the above discussions, it is reasonable to conclude that these terminal blocks will perform their intended safety function when expos1;d to harsh environments.
Therefore, continued operation of Unit 2 with this equip-ment, albeit incomplete qualification documentation, will have no impact on plant safety.
Attachments cc:
Mr. Richard C. DeYoung, Director NRG Office of Inspection and Enforcement Division of Reactor Operations Inspection Washington, D. C. 20555 Mr. Zoltan R. Rosztoczy, Branch Chief NRG Equipment Qualification Branch Division of Engineering Washington, D. C.
20555 Mr. James P. O'Reilly, Regional Administrator Office of Inspection and Enforcement Region II 101 Marietta Street, Suite 3100 Atlanta, Georgia 30303 (8 copies)
(1 copy)
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