ML20207B063
| ML20207B063 | |
| Person / Time | |
|---|---|
| Site: | Hatch  |
| Issue date: | 11/06/1986 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20207B062 | List: |
| References | |
| TAC-62029, NUDOCS 8611110456 | |
| Download: ML20207B063 (5) | |
Text
_ _ _
'l p Kt?
- o UNITED STATES g
8 NUCLEAR REGULATORY COMMISSION o
g j-w
_ Asumarow,p.c.aossa j
....J SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION
^
SUPPORT AMENDMENT NO. 67 TO FACILITY OPERATING LICENSE NO.
NPF-5 GEORGIA POWER COMPANY OGETHORPE POWER CORPORATION HUNICIPAL ELECTRIC AUTHORITY OF GEORGIA CITY OF DALTON, GEORGIA J
EDWIN I. HATCH NUCLEAR PLANT, UNIT NO. 2 DOCKET NO. 50-366
1.0 INTRODUCTION
By letter dated July 18, 1986 (Reference 1), the Georgia Power Company (GPC) proposed changes to the Hatch Plant Unit 2 Technical Specifications thatwould(1)reviseallowablevaluestoprovidefortheuseof Rosemount, as well as Barton, transmitters for certain instrumentation channels associated with the Analog Transmitter Tri provide certain administrative clarifications; (3) p System (ATTS); (2) revise allowable values for instruments which actuate on high drywell pressure; and (4) lower the core spray and residual heat removal low pressure coolant injection low reactor pressure injection permissive _ setpoints to allow for increased flexibility in the use of Rosemount transmitters for this trip function.
Additional information was provided by letters dated September 26, 1986 (Reference 2)andOctober 15, 1986 (Reference 3) in response to staff requests.
2.0 EVALUATION The original design of the ATTS used Barton Models 763 and 764 transmitters. GPC has decided to replace the Barton transmitters with Rosemount Models 1153 and 1154 transmitters, because they offer
-increased operational and maintenance flexibility. Because the accuracy j
characteristics of those transmitters differ, the Technical Specifications allowable values need to be revised in order to accommodate the new f
transmitter types.
In particular, the following changes were proposed in change 1:
i
,em
$8@.
Present Proposed lg Trip Function Allowable Value Allowable Value
- en
,so Reactor Vessel Water Level 1
-121.5 inches
-113 inches 4x Reactor Vessel Water Level 2
-55 inches
-47 inches So Reactor Vessel Water Level 3 8.5 inches 10 inches
,. SQ Reactor Shroud Water Level 0
-207 inches
-202 inches Reactor Vessel Steam Dome
! Im Pressure Low 325 psig 335 psig i
$@n.
HPCI Steam Line High Flow 307%
303%
RCIC Steam Line High Flow 307%
31P.%
J
.,---,-,...,,.._-,,,.-,-,-.-,.ge.._-.--4
-w.
Since there is no change of analytical limits, there will be no effect on the staff approved safety analyses as a result of the proposed change 1.
The proposed change 2 provides administrative clarifications or corrections-to the Technical Specifications as follows:
A.
Correct the parts number for the ATTS recirculation pump trip instruments appearing in Table 3.3.1-1.
Correct parts numbers 2B21-N024 A, B and 2821-N025A, B would replace the presently listed 2B21-N681 A, B, C, D.
B.
The reactor shroud water level trip (2B21-N685 A, B), as listed in Table 3.3.3-1, is not a high-level trip. Thus, the word "high" is deleted from the table.
C.
The suppression chamber water level high trip function (2E41-N662A,'B) used an arbitrary-zero point to derive the allowable value. Thenewallowablevalue(154.2inchesversus 33.2 inches) is derived from the torus invert. The actual level is unchanged.
D.
The suppression pool area differential temperature high system allowable value-is proposed to be changed from 42.5*F to 42 F for simplicity.
Since this change does not impact any plant operation, there will be no effect on the staff approved safety analyses as a result of the proposed change 2.
During the forthcoming refueling outage, the presently installed Barton 4
Model 746 transmitters which provide the high drywell pressure trip function, would be replaced with Rosemount Model 1154 transmitters. This modification necessitates a revision of the Technical Specifications allowable value for the high drywell pressure trip function.
It was proposed to revise the allowable values to bound the use of either Barton or Rosemount transmitters. The calculated allowable value of 1.70 psig, however, was unacceptably low from an operation's standpoint such that spurious trips during drywell inerting would likely occur. A new allowable value was calculated using a smaller range Rosemount 1154 transmitter. The proposed allowable value for this transmitter type (1.92 psig) was developed using the 2.0 psig analytical limit and the criteria of Regulatory Guide 1.105. Since there is no change of analytical limits, I
there will be no effect on the staff approved safety analyses as a result of the proposed change 3.
Change 4 proposes to lower the allowable value for the RHR-l.PCI and core spray low reactor pressure pennissives, which open the injection valves, 4
from 422 psig to 390 psig. This change is required to allow for increased flexibility in the use of Rosemount transmitters for this function.
In order to justify this change, an equivalent relaxation to the corresponding analytical limit needs to be provided. General Electric analyzed the proposed analytical limit for its effects on fuel thermal limits and LOCA limits in MDE-263-1185 (Appendix in Reference 1).
1
. As to the fuel thermal limits, i.e. minimum critical power ratio (MCPR),
i transients governing these limits occur at relatively high pressure, far above the operating ranges of the RHR-LPCI and core spray low reactor pressure permissive. Therefore, the fuel thermal limits are not impacted by this proposed change 4.
As to the LOCA limits, the core maximum average planar linear heat generation rate (MAPLHGR) limits were detennined by analyzing the postulated LOCAs in accordance with 10 CFR 50. General Electric's evaluation (Appendix in Reference 1) showed that the proposed change 4 to the low pressure injection permissive would not have a significant effect on peak clad temperature (PCT) for the limiting design basis accident.
Because PCTs for certain fuel types and exposures are presently at or near the limiting value 2200*F, further clarification was requested by the staff as to whether the. proposed change would result in the calculated limiting PCT remaining at or below 2200'F when calculated according to approved Appendix K models. This verification was provided by General Electric to GPC that the calculated MAPLHGR limits for Hatch-2 would not change and the calculated limiting PCT would remain at or below 2200"F (Reference 2).
GPC referenced the utilization of a setpoint methodology for the subject modifications and stated that the methodology is consistent with that previously reviewed and accepted by the staff during its evaluation of setpoint modifications (Amendment 39 to Hatch, Unit 2 Operating License) related to the implementation of the original ATTS design for Hatch, Unit 2.
The staff based its' acceptance of the original ATTS setpoint modification on the review of information submitted in a June 7, 1984 letter from GPC. The subject letter contained (1) specific responses to NRC requests for information related to the setpoint methodology program and (2) information prepared by General Electric (GE) which addresses the specific setpoint calculation methodology utilized for Hatch, Unit 2.
The staff's evaluation of this information was provided in the Safety Evaluation for Amendment 39 and was enclosed with the amendment in the staff's July 13, 1986 letter to Mr. J. T. Beckham, Jr., Georgia Power Company.
GPC has verified by letter dated October 15, 1986 that the information provided in the June 7,1984 letter (with additional clarification information) remains valid in support of the latest request for ATTS setpoint changes. The staff has reviewed the clarification information and finds it to be acceptable.
Based on the above discussion, we conclude that the proposed Technical Specification changes are acceptable.
3.0 ENVIRONMENTAL CONSIDERATION
S 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 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 this 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).
Pursuantto10CFR51.22(b),noenvironmentalimpact 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 abeve, 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 the amendment will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributor:
D. Yue and R. Stevens Date: November 6, 1986 e
c -
e
.. REFERENCES 1.
Letter from J. T. Beckham, Jr., Georgia Power Company, to D. Muller, NRC, July 18 1986.
2.
Letter from L. T. Gucwa, Georgia Power Company, to D. Muller, NRC, September 26, 1986.
3.
Letter from L. T. Gucwa, Georgia Power Company to D. Muller, NRC, October 15, 1986.
e a
1
- _ - -