ML20056G330
| ML20056G330 | |
| Person / Time | |
|---|---|
| Site: | Hope Creek  |
| Issue date: | 08/18/1993 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20056G329 | List: |
| References | |
| NUDOCS 9309030005 | |
| Download: ML20056G330 (4) | |
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDNENT NO. 57 TO FACILITY OPERATING LICENSE NO. NPF-57 PUBLIC SERVICE ELECTRIC & GAS COMPANY i
ATLANTIC CITY ELECTRIC COMPANY HOPE CREEK GENERATING STATION f
DOCKET NO. 50-354 i
1.0 INTRODUCTION
I By letter dated May 6,1993, the Public Service Electric and Gas Company (the I
licensee) submitted a request for changes to the Hope Creek Generating i
Station, Technical Specifications (TS). The requested changes would modify the requirements of Technical Specification 3.3.2, Table 3.3.2-1, Action 26, l
which mandates that the filtration, recirculation, and ventilation system 1
(FRVS) be in operation when the reactor vessel water level instrumentation is inoperable. The proposed changes would not require FRVS to be in operation i
while the reactor _ vessel water level instrumentation is inoperable provided additional conditions are met.
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2.0 BACKGROUND
The FRVS is an Engineered Safety Feature designed to minimize offsite doses in the event of a loss of coolant accident, a refueling accident, or a high i
radioactivity event in the' reactor building.
FRVS is automatically started in response to the following signals:
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High drywell pressure, b.
Low reactor vessel water level (Level 2),
Refueling floor exhaust duct high radioactivity, c.
d.- Reactor building exhaust air high radioactivity, and e.
Reactor building ventilation system isolation.
l In addition, the FRVS can also be manually started from the main control room.
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' During refueling operations, there exists the potential that a loss of coolant accident or-inadvertent diversion of RCS water could lead to a draining of the l-reactor vessel. With the reactor vessel level instrumentation inoperable, an automatic initiation based on a Level 2 start signal for the FRVS would not be possible. To' compensate for the loss of level start signal in this case, current plant technical specifications require that the FRVS be in operation when the reactor vessel level instrumentation is inoperable.
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. l During refueling operations, the reactor vessel level instrumentation is periodically removed from service for maintenance purposes. When this occurs, the FRVS must be put into operation. While the FRVS is in operation, condensation forms on the ductwork and results in high humidity conditions on the refueling. floor. This creates both an uncomfortable work environment for plant personnel and difficulties related to contamination control.
l Additionally, operation of the FRVS increases the usage time for the charcoal filters within this system. As a result, sampling and testing of these filters as required by plant Technical Specification Surveillance requirements must be completed more often.
i To compensate for the loss of level actuation signal to the FRVS, the amendment specifies additional criteria which must be met during periods when the reactor vessel level instrumentation is inoperable.
3.0 EVALUATION The FRVS is required to be in operation with the reactor vessel water level instrumentation inoperable to compensate for the loss of an automatic initiation signal in the event that the water level in the reactor vessel decreases below the Level 2 setpoint. With the FRVS in operation, it would be available to mitigate the consequences of a radiological release to the refueling floor in the event of a significant decrease in reactor vessel water l
level. The additional criteria specified in this amendment ensure that other alarms would alert operators to a draindown of the reactor vessel.
The first criterion requires that the water level in the reactor cavity be at least 22 feet 2 inches above the reactor vessel flange when level instrumentation is inoperable. At this minimum water level, there is a total of 547,745 gallons above the reactor vessel flange.
In order to reach the Level 2 setpoint, the loss or diversion of more than 550,000 gallons of water from the refueling cavity and the reactor vessel would be required.
During periods when the refueling cavity is flooded, plant personnel will usually occupy the refueling floor. Plant personnel in this vicinity would probably l
notice a loss of inventory of this magnitude.
If a draindown of the reactor vessel cavity to the suppression pool were to occur, the stipulations requiring operability of the suppression pool high level alarm and maintaining a level in the suppression pool at or above 5 inches indicated level would serve to alert operators to a loss of inventory event. Diverting water from the reactor vessel to the suppression pool would l
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, lead to an increase in the suppression pool water level. At an initial suppression pool level of 5 inches indicated level, the addition of 482,490 gallons of water would lead to a high suppression pool water level alarm in the control room.
The spent fuel pool is equipped with a low water level alarm. Decreasing the water level in the refueling cavity with the fuel pool gates open would concurrently decrease the water level in the fuel pool. A cuntinued decrease in level would actuate the low fuel pool level alarm in the main control room alerting operators to the loss of inventory. This alarm would occur irrespective of the leak /draindown path from the reactor vessel.
In addition, the design of the spent fuel pool cooling system is such that the decreased level.in the pool would lead to a fuel pool cooling pump trip. A fuel pool cooling pump trip will'also cause an alarm in the control room.
An undetected loss of inventory event resulting in the draining of the refueling cavity would also decrease water level in the dryer / separator pit.
If the draindown went undetected, the water level would drop low enough to expose the dryer / separator assembly. Upon exposing these reactor vessel internals high refueling floor radioactivity levels would automatically initiate FRVS.
The licensee proposes to delete the requirement which mandates that the FRVS be in operation when the reactor vessel level instrumentation is inoperable.
l This modification along with the additional criteria necessary to meet this condition specified in the amendment weie evaluated by the staff.
Based on this evaluation, the staff finds the proposed changes acceptable.
3.0 STATE CONSULTATION
In accordance with the Commission's regulations, the New Jersey State Official was ' notified of the proposed issuance of the' amendment. The State official had no comments.
4.0 ENVIRONMENTAL CONSIDERATION
The 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 NRC 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 connent on such finding (58 FR 34090). Accordingly, the amendment meets _the eligibility criteria for categorical exclusion set forth in 10 CFR l
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.
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5.0 CONCLUSION
The Commission has concluded, based on the considerations discussed above, that:
(1) there is reasonable assurance.that the health and safety of the
.public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security'or to the health and safety of the public.
i Principal Contributor:
P. Rush Date: August 18, 1993 i
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