ML19273B232
| ML19273B232 | |
| Person / Time | |
|---|---|
| Site: | Salem  |
| Issue date: | 03/06/1979 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML19273B233 | List: |
| References | |
| NUDOCS 7904060012 | |
| Download: ML19273B232 (3) | |
Text
8 UNITED STATES
[V
[*4 NUCLEAR REGULATORY COMMisslON WASHINGTON, D. C. 20565 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDMENT N0. 15 TO FACILITY OPERATING LICENSE NO. DPR-70
'IBLIC SERVICE ELECTRIC AND GAS COMPANY, PHILADELPHIA ELECTRIC COMPANY, DELMARVA POWER AND LIGHT COMPANY, AND ATLANTIC CITY ELECTRIC COMPANY SALEM NUCLEAR GENERATING STATION, UNIT NO. 1 DOCKET NO. 50-272 Introduction By letter dated January 12, 1979 and telecopied to the NRC on thas date, Public Service Electric and Gas Company (PSE&G) requested a temporary change to the Technical Specifications appended to Facility Operating License DPR-70 for the Salem Nuclear Generating Station Unit No.1.
The proposed change involved revision of the time limita-tion that the Boron Injection Tank (BIT) is permitted to be inoperable prior to havin9 the reactor in HOT STANDBY and borated to a SHUTDOWN MARGIN equivalent to 1% ak/k. The staff performed a safety evaluation of this request and authorized by telephone, an emergency Technical Specification change on January 12, 1979 which was confirmed in writing on January 12, 1979.
Background
At 10:55 A.M. on January 12, 1979 while at power, the Boron Injection Tank (BIT) was found to be out of Technical Specification 3.5.4.1 tolerance for boron concentration.
Efforts were started to increase the BIT boron concentration.
At 11:55 A.M. since the concentration, while increasing was still not within tolerance limits, the licensee proceedaltowards HOT STANDBY by initiating a power reduction.
When it became apparent that the concentrations would not be restored within the six hours allowed to achieve the H0T STANDBY condition of ACTION STATEMENT 3.5.4.1, the licensee performed a safety evaluation to demonstrate that it would be safe to continue to operate the plant at 7904060 0
- power with the existing concentration while the concentration was being returned to within tolerance limits. On the basis of that evaluation, the licensee requested NRC to grant a one time 18 hour2.083333e-4 days <br />0.005 hours <br />2.97619e-5 weeks <br />6.849e-6 months <br /> extension of time in the HOT SHUTDOWN requirement. The intent of this extension was to allow time for the boron concentration to complete its return to within Technical Specification 3.5.4.1 limits,41thout further power reduction. We perfomed a review of this matter, as discussed below, and grar,td de requested extension.
Evaluation The The BIT is provided as part of the Emergency Core Cooling System.
Technical Specification on the lower limit for boron concentration in the BIT water is required to ensure that sufficient negative reactivity is injected into the core to promptly counteract any positive increase in reactivity caused by inadvertent cooldown of the reactor coolant Such cooldown.could be caused by inadvertent depressurization, system.
a loss-of-coolant accident or a main steam line rupture.
The minimum capability for injection of high concentration boron (20,100 ppm) is based on the most restrictive core conditions:
end-of-life shutdown margin, equilibrium xenon conditions, most reactive control rod assembly stuck in its fully withdrawn position, and the negative moderator coefficignt corresponding to the end-of-life, rodded core.
For the conditions existing on January 12, 1979, the licensee detennined by calculations that a boric acid concentration of 16,000 ppm in the BIT would be sufficient to ensure the required shutdown margin of 1% ak/k at 2000F, should the reactor experience an inadvertent cooldown from full power.
We have reviewed the licensee's analysis and agreed with the conclusions stated. The analysis was based on (1) actual control rod worth, (2) the value of the moderator coefficient at the actual time in cycle rather than at end-of-life (E0L) and (3) the normal assumption of the worst reactive RCCA stuck in the fully withdrawn position.
We also agreed that an analysis using the then present plant conditions was acceptable and that the margin Detween the actual boron concentration of 18,522 ppm and the value required to maintain adequate shutdown margin,16,000 ppm, was suf ficient to compensate for any uncertainties in the then present plant values for moderator temperature coefficient and rod worths.
. In conclusion, we found that an 18 hour2.083333e-4 days <br />0.005 hours <br />2.97619e-5 weeks <br />6.849e-6 months <br /> extension of the time limitation (from 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />) that the BIT is permitted to be " inoperable",
(i.e., outside limits for boron concentration) without being in the HOT STANDBY called for in Action Statement 3.5.4.1, was an acceptable temporary Technical Specification change at the then current exposure history (12,800 MhD/MTU) for Salem Unit No.1.
Environmental Considerations We have determined that the amendment does not authorize a change in effluent types or total amounts nor an increase in power level and will not result in any significant environmental impact.
Having made this determination, we have further concluded that the amendment involves an action which is insignificant from the standpoint of environmental impact and pursuant to 10 CFR 651.5(d)(4) that an environmental impact statement or negative declaration and environmental impact appraisal need not be prepared in connection with the issuance of this amendment Conclesion We have concluded, based on the considerations discussed above, that:
(1) because the amendment does not involve a significant increase in the probability or consequences of accidents previously considered and does not involve a significant decrease in a safety margin, the amendment does not involve a significant hazards consideration, (2) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, and (3) such activities will be conducted in compliance with the Commission's regulations and the issuance of this amendment will not be inimical to the coranon defense and security or to the health and safety of the public.
Dated: March 6, 1979