ML17156A176
| ML17156A176 | |
| Person / Time | |
|---|---|
| Site: | Susquehanna  |
| Issue date: | 04/23/1985 |
| From: | NRC |
| To: | |
| Shared Package | |
| ML17156A175 | List: |
| References | |
| NUDOCS 8504300062 | |
| Download: ML17156A176 (5) | |
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UNITEDSTATES NUCLEAR REGULATORY COMMISSION WASMINGTON,D. C. 20555 SAFETY EVALUATION AMENDMENT NO.
TO NPF-14 AND AMENDMENT NO.
TO NPF-22 SUSQUEHANNA STEAM ELECTRIC STATION, UNITS 1 AND 2 DOCKET NOS.
50-387 AND 50-388 Introduction (Unit 1)
By letter dated September 6, 1984, Pennsylvania Power and Light Company (the licensee) made application to amend the Technical Specifications of the Susquehanna Steam Electric Station, Unit 1.
The proposed changes would:
(1)
Revise the trip setpoint on the Rod Block Monitor to provide dual settings with corresponding operating limit Minimum Critical Power Ratio (MCPR) values; (2)
Reanalyze. those transients taking credit for the Reactor Pump "Trip to account for the measured flow coastdown characteristics and revise the MCPR operating limits accordingly; and (3)
Revise the labels on Figures 3.2.3-1a and 3.2.3-1b to increase their clarity.
Evaluation (Unit 1
1.
Rod Block Monitor Trip Setpoints The analysis of the rod withdrawal error at power produces a table of ch'anges in Critical Power Ratio (Delta CPR) as a function of the trip setpoint of the Rod Block Monitor.
The licensee has proposed to employ two different settings-108 percent full power and 106'ercent full power.
The higher values would be used at low powers and the lower value when operating at or near full power.
Alternatively the higher value might be used in portions of the cycle when normal operating margins are high and the smaller value when they are low.
The higher value of trip setpoint requires larger operating MCPR values than does the lower value.
Accordingly the curve of MCPR as a function of the scram speed parameter
( 7 ), Figure 3.2.3-1, has been replaced by two Figures - 3.2.3-1a for the 106 percent trip setpoint and 3.2.3-1b for 108 percent.
The Technical Specification 3/4.2.3 has been revised to reflect this change.
Since the increased setpoint of the Rod Block Monitor is accompanied by a requirement for.an increased operating MCPR in order to maintain margins to safety limits we conclude that this, change is acceptable.
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PDR ADOCK 05000387 PDRJ
~2.
Recirculation Pump Coastdown Events During startup testing of Unit 1 it was discovered that the coastdown flow during the first second following a recirculation pump trip was larger than had been assumed in safety analyses.
Operation was continued by invoking the operating limit MCPR values appropriate to the case in which the pump trip was inoperable..
The vendor, General Electric, has-since-reanalyzed the events which might be affected by the altered coastdown curve and prepared revised operating limit MCPR values.
The analysis was performed with the same codes and procedures as was employed for the FSAR analyses and the operating limit MCPR values have been increased to provide the same margin to safety limits as before.
We find this to be acceptable.
3.
Revised Labels for OLMCPR Curves The curves'perating Limit MCPR (OLMCPR) as a function of the scram time parameter, +,
h'as been relabeled in order to more clearly identify the conditions under which each of the curves is applicable.
Since this change reduces the likelihood of confusion as to which of the curves in Figures 3.2.3-1a and 3.2.3-1b are to be used for the OLMCPR we find the proposed change acceptable.-
Introduction (Unit 2)
By the same letter dated September 6,
1984, Pennsylvania Power and Light Company (the licenspe) made application to amend the Technical Specification of the Susquehanna Steam Station, Unit 2.
The proposed changes would:
(1)
Revise the trip setpoint on the Rod Block Monitor to provide dual settings with corresponding operating limit MCPR values; (2)
Revise the labels on Figures 3.2.3-la and 3.2.3-1b to increase their clarity; Evaluation (Unit 2) 1.
Rod Block Monitor Trip Setpoints The analysis of the rod withdrawal error at power produces a table of changes in Critical Power Ratio (Delta CPR) as a function of the trip setpoint of the Rod Block Monitor.
The licensee has proposed to employe two different settings
- 108 percent full power and 106 percent full power.
This higher value 'would be used at low power and the lower value when operating at or near full power.
Atlernatively the higher value might be used in portions of the cycle when normal operating margins are high and the smaller value when they are low.
The higher value of trip setpoint requires larger operating
MCPR values than does.the lower value.
Accordingly the curve of MCPR as a
function of the scram speed parameter
( V), Figure 3.2.3-1, has been replaced by two figures - 3.2.3-1a for the 106 percent trip setpoint and 3.2.3-lb for the 108 percent.
The Technical Specification 3/4.2.3 has been revised to reflect this change.
Since the increased setpoint of the Rod Block Monitor is accompanied bp a requirement for an increased operating MCPR in order to maintain margins to safety limits we conclude that this change is acceptable.
2.
Revised Labels for OLMCPR Curves The curves of Operating Limit MCPR (OLMCPR) as a function of the scram time parameter,V, has been relabeled in order to mor e clearly identify the con-ditions under which each of the curves is applicable.
Since this change reduces the likelihood of confusion as to which of the curves in Figures 3.2.3-1a and 3.2.3-1b are to be used for the OLMCPR we find the proposed change acceptable.
Conclusion (Units 1 and 2
The proposed changes to the Susquehanna Unit 1 and Unit 2 Technical Specifi-cations are found to be acceptable to the NRC staff.
These modifications do not involve any significant safety considerations.
We, therefore, recommend approval of the changes to the Unit 1 and Unit 2 Technical Specifications as proposed by the licensee.
Environmental Consider ation These amendments involve changes in the 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 amendments involve 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 incr ease in indivi-dual or cumulative occupational radiation exposure.
The Commission has previously issued a proposed finding that these amendments involve no signi-ficant hazards consideration and there has been no public comment on such finding.
Accordingly, these amendments meet the eligibility criteria for categorical exclusion set forth in 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 these amendments.
Conclusion We have 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, and (2) such activities will be conducted. in compliance with the Commission's regulations and the issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public.
Dated:
APR 3 3 ]985