ML19263E789
| ML19263E789 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 06/22/1979 |
| From: | Brown S VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | Harold Denton, Parr O Office of Nuclear Reactor Regulation |
| References | |
| 459-060179, 459-60179, NUDOCS 7906250280 | |
| Download: ML19263E789 (2) | |
Text
- r.
3 CO VIRGINI A ELECTRIC AND POWER COMP ANY, RICHMONO, VIRGINI A 23261 June 22, 1979 Mr. Harold R. Denton, Director Serial No. 459/060179 Office of Nuclear Reactor Regulation PSE&C/JMD:mac: wang Attention: Mr. 0. D. Parr, Chief Light Water Reactors Branch No. 3 Docket No. 50-339 Division of Project Management U. S. Nuclear Regulatory Commission Washington, D. C.
20555
Dear Mr. Denton:
We have reviewed your letter dated June 1, 1979 concerning, " Instrument Qualification" and we have the following additional information in response to your letter.
The justification for use of the Barton Transmitters at North Anna was presented as an attachment to our letter of August 22, 1978, Serial No. 424.
However, additional justification has been provided since that submittal.
In a letter sent to Mr. Harold R. Denton, Serial No. 541, September 29, 1978, we submitted a report entitled " Westinghouse Reactor Protection System /
Engineered Safety Features Actuation System Setpoint Methology."
That report contains a table which shows instrument setpoints and allowed deviations.
You will note that an allowance of +14% has been made for the Barton 763 Narrow Range Prcssurizer Pressure to account for the inaccuracies which were seen during LOCA testing.
In a follow-up letter, Serial No. 565, October 13, 1978, we indicated that the trip setpoints at North Anna had been revised based on the new methodology, therefore the eniironmental affects of the LOCA testing have been accounted for by a setpoint change.
Also, additional testing performed by Westinghouse and reported in NS-TMA-1059, dated September 29, 1978, demonstrates that inaccuracies would be within specification for radiation doses and environments characteristic of design. basis events.
In the NRC evaluation letter (dated May 15, 1978) of NS-TMA-1950 the Staff did request Westinghouse to perform additional confirmatory testing on production Lot 1 Barton transmitters to demonstrate their long-term acceptability. Westinghouse will be completing an additional test program on the Barton Lot 1 transmitters to provide the additional justification requested by the NRC.
Preliminary results are expected to be available by the requested date of September,1979. Westinghouse states that the details of this additional test program have not yet been finalized, but will be submitted to the rRC within the stipulated period.
The safety evaluation contained in Attachment 2 to Vepco, letter Serial No. 424, states that under a steam line rupture transient condition, reactor vessel integrity is assured far in excess of one effective full power year based on a fracture mechanics analysis performed by Westinghouse.
2214 344 4
7906250270 g