ML20207J003
| ML20207J003 | |
| Person / Time | |
|---|---|
| Site: | Hatch  |
| Issue date: | 12/29/1986 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20207H974 | List: |
| References | |
| TAC-63412, NUDOCS 8701080252 | |
| Download: ML20207J003 (3) | |
Text
' 4"Np uz UNITED STATES e
8 NUCLEAR REGULATORY COMMISSION o
5 E
WASHINGTON, D. C. 20555 M
m
/
SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDMENT N0. 71 TO FACILITY OPERATING LICENSE NO. NPF-5 GEORGIA POWER COMPANY OGLETHORPE POWER CORPORATION MUNICIPAL ELECTRIC AUTHORITY OF GEORGIA CITY OF DALTON, GEORGIA EDWIN I. HATCH NUCLEAR PLANT, UNIT N0. 2 DOCKET N0. 50-366
1.0 INTRODUCTION
i By letter dated November 10, 1986, Georgia Power Company requested that the Hatch Unit 2 Technical Specification Sections related to operability requirements for the Main Control Room Environmental Control System (MCRECS) be modified to (1) delete the requirement for automatic actuation of the control room pressurization mode of operation of the MCRECS upon receipt of a low-low reactor vessel water level signal, (2) change the requirement for automatic actuation of the control room pressurization mode of the MCRECS upon receipt of a high radiation signal in the refueling floor exhaust to require automatic actuation based on a high radiation signal in the refueling floor area (i.e., the word " exhaust" would be replaced by the word " area", (3) change the location and format of the requirements related to the operability of the MCRECS to clarify and facilitate their use, (4) correct errors in the identification numbers listed for instrumentation that provides actuation signals for operation l
of the MCRECS, and (5) augment the MCRECS applicability requirements (Operational Conditions for which the MCRECS is required to be operable) l to include additional Operational Conditions.
Proposed changes (1) and (2) above are needed to make the Technical Specifications compatible with the existing plant design and the design as described and evaluated in the Hatch Unit 2 Final Safety Analysis Report.
2.0 EVALUATION With respect to change (1), the existing Technical Specification requires that the control room pressurization mode of MCRECS operation be l
automatically actuated upon receipt of a low-low (Level 2) reactor vessel j
water level signal and also upon receipt of a low-low-low (Level 3) reactor vessel water level signal.
In addition, the existing Technical Specification also requires actuation of the control room pressurization mode based on high drywell pressure. Thus, even with deletion of the low-low reactor vessel water level signal, the remaining low-low-low reactor vessel water level actuation requirement together with this high drywell pressure actuation requirement continue to provide diverse LOCA l
signal actuation of the control room pressurization mode, and the 8701080252 861229 PDR ADOCK 05000366 P
j v
i
.o elimination of the redundant reactor vessel water level actuation l
requirement does not significantly change the safety margin provided by the current Technical Specification requirements.
It is also noted that the Standard Review Plan and the Standard Technical Specifications do not specify a requirement for actuation of the control room pressurization mode based on low reactor vessel water level. On the basis of the above discussion, we conclude that deletion of the requirement for automatic actuation of the control room pressurization mode based on a low-low reactor vessel water level is acceptable.
With respect to change (2), the area radiation monitors that will actuate the control room pressurization mode of MCRECS operation are area radiation monitors 2011-K002A and D and are located in the refueling floor area close to the exhaust ducts rather than inside the ducts as currently required. They are located approximately five feet above the refueling floor and directly below the vent duct on the wall. These locations assure that air flow in the refueling area will be monitored before entering the vent ducts.
In addition, the design basis fuel handling accident described in Hatch Unit 2 FSAR Section 15.1.4.1 indicates that the resultant radiological doses are sufficiently high to trip off the set points of these area radiation monitors and provide signals to isolate the MCRECS.
The refueling area exhaust radiation monitor which actuates secondary containment isolation in the event of release of activity in the refueling area, in effect, acts as a backup to the area radiation monitors.
It signals the control room that it has actuated on high radiation levels.
The control room operators would then be able to manually actuate the control room pressurization mode of MCRECS operation before this release becomes a problem for control room.
On the basis of the abo /e discussion, we conclude that the change to require automatic actuation of the control room pressurization mode based on signals from the refueling floor area radiation monitors rather than on refueling area exhaust monitors is acceptable.
Changes (3) and (4) do not modify any current Technical Specification requirements. They change the location and format of information and correct instrument numbers related to MCRECS requirements. We conclude that these changes improve the Technical Specifications, and are acceptable.
The current Technical Specifications do not explicitly require that actuation of the MCRECS control room isolation mode of operation be demonstrated. However, operability of the isolation mode is needed in all Operational Conditions because a chlorine release accident can be postulated to occur independent of the reactor Operational Condition.
V
. y I
- The current Technical Specifications do not require that the MCRECS control room pressurization mode of operation be operable during Operating Condition 5 (Refueling) or other fuel handling operations. However, operability of the control room pressurization mode is needed whenever irradiated fuel is being handled because a fuel handling accident that might require actuation of the control room pressurization mode can be postulated to occur in these situations.
Change (5) adds requirements a) that the control room isolation mode of MCRECS operation shall be operable when the reactor is in Operational Conditions 4 and 5 (Cold-Shutdown and Refueling) and b) that the control room pressurization mode of MCRECS be operable when the reactor is in Operational Condition 5 and when irradiated fuel is being handled in the secondary containment. We conclude that these additions should increase the safety of operation in' these situations and are acceptable.
3.0 ENVIRONMENTAL CONSIDERATION
S This amendment changes a requirement with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20.
The staff has determined that the amendment involves no significant 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 increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that the amendment involves no significant hazards consideration and there has been no public comment on such finding. Accordingly, the amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9).
Pursuant to 10 CFR 51.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendment.
4.0 CONCLUSION
We have concluded, based on the considerations discussed above, that:
(1) there is reasonable assurance that the health and safety of the will not be endangered by operation in the proposed manner, and (2) public such activities will be conducted in compliance with the Commission's regulations, and the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributors:
G. Rivenbark, A. Chu, M. Lamastra Dated:
December 29, 1986 4
7