ML13304A347
| ML13304A347 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 06/23/1988 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML13304A346 | List: |
| References | |
| NUDOCS 8807210336 | |
| Download: ML13304A347 (1) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATING TO THE OFFSITE HAZARDS EVALUATION SOUTHERN CALIFORNIA EDISON COMPANY SAN ONOFRE NUCLEAR -ENERATING STATION UNITS 2 AND 3 DOCKET NOS. 50-361 AND 50-362 By letter dated February 8, 1988, Southern California Edison Company (SCE) submitted the results of a survey of nearby hazardous cargo traffic.
This survey was conducted in accordance with San Onofre Nuclear Generating Station (SONGS) Units 2 and 3 Technical Specification 6.9.1.14, which requires that the licensee periodically monitor the hazardous cargo traffic on Interstate 5 (1-5) and the AT&SF railway in the vicinity of the plant.
The staff has reviewed SCE's analysis of the survey results and concurs with the licensee that the risk to the plant from hazardous cargo traffic on the above transportation routes is acceptably small and is within the guidelines of Standard Review Plan (SRP) 2.2.3. Specifically, the results of the survey indicate that the risk of toxic gas incapacit-at on of the control room operators remains acceptably small (less than 10
/year).
Similarly, the risk with respect to traffic accidents involving explosions also remains acceptably low (less than 10-'/year).
It should be noted, however, that SCE's analysis of the survey results is incorrect in its application of the SRP 2.2.3 guidelines to toxic gases. The licensee applies the guidelines individually to each event involving the release of a particular toxic gas. On this basis, the licensee concludes that the risk of control room operatior incapacit ation due to each toxic material separately is within the guidelines.
The correct procedure is to sum the contributions from all relevant toxic material events and to apply the SRP 2.2.3 guidelines to the resultant aggregate toxic gas risk. In the case of SONGS 2 and 3, however, the contributions from chlorine and ammonia need to be subtracted, since specific protection against these is provided for in the plant design. On this basis, te survey results indicate that the total toxic gas risk is less than 10 /year.
With proper application of SRP 2.2.3 guidelines, as described above, and on the basis of the current hazardous cargo traffic near SONGS 2 and 3, the staff finds that the total risk with respect to each type of hazard (i.e., toxic gas, overpressure) remains acceptably small.