ML20059E021
| ML20059E021 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 12/30/1993 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20059E018 | List: |
| References | |
| NUDOCS 9401100196 | |
| Download: ML20059E021 (2) | |
Text
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O cea d
'o UNITED STATES g
NUCLEAR REGULATORY COMMISSION n
(
WASH 1NGTON, D. C. 20555 b
SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION I
RELATED TO AMENDMENT NO.
183 TO FACILITY OPERATING LICENSE NO. NPF-3 TOLEDO EDIS0N COMPANY CENTERIOR SERVICE COMPANY THE CLEVELAND ELECTRIC ILLUMINATING COMPANY DAVIS-BESSE NUCLEAR POWER STATION. UNIT NO. 1 DOCKET NO. 50-346 L
1.0 INTRODUCTION
By letter dated August 30, 1993, Toledo Edison Company requested a revision to the Technical Specifications for the Davis-Besse Nuclear Power Station (DBNPS).
The proposed amendment adds an Action statement to Technical Specification (TS) 3/4.6.3, " Containment Hydrogen Dilution System," which would apply when both containment hydrogen dilution (CHD) systems are inoperable.
The change would allow 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to return one of the two inoperable CHD systems to operable status or be in at least Hot Standby within the next six hours. Also, the associated TS bases Rection 3/4.6.4,
" Combustible Gas Control," would be revised to cit. afy the discussion of the CHD and containment hydrogen purge systems, and to add mention of the capability to install an external hydrogen recombination system.
[
2.0 EVALUATION The combustible gas control system is designed to control the concentration of hydrogen which may be released wit'.in the containment vessel atmosphere following a loss-of-coolant accident (LOCA). The system is composed of the CHD systems and the hydrogen purge (HP) system. As a backup to the CHD and HP systems, the capability to install an external hydrogen recombination system has been provided at DBNPS.
s The lower flammability limit for hydrogen that is assumed for a pust-LOCA j
environment is four percent by volume. The combustible gas control systems are designed to be operated as necessary to maintain hydrogen concentration in the containment vessel at or below three percent by volume following a LOCA.
9401100196 931230 M
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t Hydrogen concentrations of three percent and four percent are calculated.to be 1
reached in approximately 17 days and 28 days following a postulated design basis LOCA at DBNPS. This amount of time is ample for either returning one CHD system to service or for installing the external hydrogen recombination system in the event that a LOCA occurs when both CHD systems are inoperable.
Therefore, the proposed 72-hour action statement for both CHD systems inoperable is acceptable.
The change to the associated bases is just clarifying in nature and is acceptable.
Based on the above, the NRC staff finds that'the proposed amendment to add an action statement for two CHD systems inoperable is acceptable.
3.0 STATE CONSULTATION
In accordance with the Commission's regulations, the Ohio State official was notified of the proposed issuance of the amendment.
The State official had no comments.
4.0
[NVIRONMENTAL CONSIDERATION l
This amendment changes a requirement witn respect to installation or.use of a l
facility component located within the restricted area as defined in 10 CFR Part 20. The staff has determined that the amendment involves no si'nificant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite, and that there is no significant j
increase in individual or cumulative occupational radiation exposure.
The j
Commission has previously issued a proposed finding that the amendment t
involves no significant hazards consideration and there has been no public comment on such finding (58 FR 52995). Accordingly, the amendment meets the eligibility criteria for categorical exclusion set /3rth in 10 CFR 51.22(c)(9).
Pursuant to 10 CFR 51.22(b), no envirt. mental impact statement
.l or environmental assessment need be prepared in connemtion with the issuance
)
of the amendmer..
5.0 CONCLUSI0i i
The staff has concluded, based on the considerations discussed above, that-(1) there is reasonable assurance that the health and safety of the public j
will not be endangered by operation in the proposed manner, (2) such i
activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of this amendment will not be inimical ~ to the common defense and security or to the health and safety of the public.
Principal Contributor: J. Hopkins l
Date:
December 30, 1993 e,
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