ML20205G478
| ML20205G478 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 03/12/1999 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20205G477 | List: |
| References | |
| NUDOCS 9904070259 | |
| Download: ML20205G478 (8) | |
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UNITED STATES j
NUCLEAR REGULATORY COMMISSION t
WASHINGTON, D.C. ff.W50001
. SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 231 TO FACILITY OPERATING LICENSE NO. DPR 65 NORTHEAST NUCLEAR ENERGY COMPANY THE CONNECTICUT LIGHT AND POWER COMPANY THE WESTERN MASSACHUSETTS ELECTRIC COMPANY MILLSTONE NUCLEAR POWER STATION. UNIT NO. 2 DOCKET NO. 50-336
1.0 INTRODUCTION
By letter dated July 17,1998, as supplemented by letters dated November 10,1998, and.
February 11,1999, tbn Northeast Nuclear Energy Company, et al. (NNECO, or the licensee),
submitted a request for changes to the Millstone Nuclear Power Station, Unit 2, Technical Specifications (TS) regarding certain diesel generator (DG) action statements and surveillance requirements (SRs). The supplementalletters provided additionalinformation that did not change the staff's original no significant hazards consideration determination.
2.0 BACKGROUND
The licensee's requested changes would incorporate recommendations contained in Generic Letters (GLs) 84-15, " Proposed Staff Actions To improve and Maintain Diesel Generator Reliability," dated July 2,1984; 91-04, " Changes in Technical Specifications Improvements To Reduce Surveillance Intervals To Accommodate a 24-Month Fuel Cycle," dated April 2,1991;
' 93-05, "Line-item Technical Specifications improvements for Testing During Power Operatior,,-
dated September 27,1993; and NUREG -1432, " Standard Technical Specifications, Combustion Engineering Plants," Revision 1, dated April 1,1995. Specifically, the proposed changes would amend TS 3.8.1.1, " Electrical Power Systems - A.C. Sources - Operating," and 3.8.1.2, "Electncal Power System - Shutdown." Information will be added to the Bases of the TS to address the proposed changes. The proposed changes will revise the DG TS SRs to 1
achieve overallimprovement in DG reliability and availability.
j Millstone Unit 2 TS requires that while in Modes 1 through 4, as a minimum, the unit will have two physically independent circuits between the offsite transmission network and the onsite o
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Class 1E distribubon system, and two separate and independent DGs. The safety function of DGs is to supply ac electrical power to plant safety systems whenever the preferred ac power supply is unavailable.
The staff has reviewed and evaluated the changes to the TS proposed by the licensee in the following secbon.
3.0 EVALUATION 3.1 Chance 1 TS Section 3.8.1.1 Limitina Condition for Operation (LCO)"a" The word " switchyard" will be replaced by "onsite Class 1E distribution system." This change is consistent with NUPEG-0212, " Standard Technical Specification for Combustion Engineering Pressurized-Water Reactors," Revision 2, Fall 1980, and therefore, is acceptable to the staff.
3.2 Chance 2 TS Section 3.8.1.1 Action Statement "a"- One offsite circuit inoperable TS 3.8.1.1.s currently requires that if one offsite circuit breaker is inoperable, that the licensee demonstrate the operability of the remaining A.C. sources by performing Surveillance Requirement 4.8.1.1.1. It also requires that if either DG has not been successfully tested within the past 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, the licensee must demonstrate its operability by performing
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Surveillance Requirement 4.8.1.1.2.a.2. In its submittal, the licensee proposed changes to these requirements. Specifically,3.8.1.1, action statement a, would (1) state that if one offsite circuit is inoperable, perform Suiveillance Requirement 4.8.1.1.1 for the remaining offsite circuit and (2) delete the statement regarding the DG. These changes will eliminate an I
unnecessary start of the DG, are consistent with GL 93-05 and NUREG-1432 and are therefore, acceptable to the staff.
The requirement contained in the second footnote (**) to allow a one-time extension of the allowed outage time to 7 days will be deleted. This provision is no longer necessary since the Millstone Unit 1 work has been completed. The Bases explanation of this provision (*) will also I
be deleted.
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Since this change was due to an expired one-time extension, the staff accepts this change.
3.3 Chance 3 Section 3.8.1.1 Action Statement "b"- One diesel oenerator inoperable The requirement to test the remaining operable DG will be modified. Testing will not be required unless a common-cause failure is the reason for declaring the DG inoperable.
Guidance concoming common-cause failures will be added to the Bases for the specification instead of defining it in the action statement. This approach is consistent with GL 93-05 and NUREG-1432 and is tnerefore, acceptable to the staff.
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l' The time requirement for determining whether a common-cause failure exists on the other DG L
will remain at 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. Even though this time requirement is not consistent with GL 93-05, it j
is consistent with NUREG-1432.
l The requirement contained in the first footnote (*) to complete testing of the remaining DG will be based on the determination of a common-cause failure. This change will eliminate a l
potential unnecessary start of a DG. The removal of this requirement is consistent with GL 93-l 05 and NUREG-1432 and is therefore, acceptable to the staff, 3.4 Chance 4 i
i TS 3.8.1.1 Action Statement "C"- One offsite circuit and one diesel oenerator inoperable i
The wording will be changed from " remaining A.C. sources by performing Surveillance Requirement 4.8.1.1.1" to " Perform Surveillance Requirement 4.8.1.1.1 for remaining offsite circuit." This wording change is editorial in nature, and is therefore, acceptable.
The requirement to test the remaining operable DG will be modified. This proposed change is consistent with the proposed changes to Action Statement b as previously discussed in Change 3.
. As discussed in Change 3, the requirement contained in the first footnote (*) to complete the test of the remaining DG will be deleted for the same reason.
The statement that a successful test of the DG for this action statement will satisfy the required test of Action Statement a or b is no longer necessary as a result of the proposed changes l
previously discussed. Therefore, this sentence will be deleted.
These changes are acceptable to the staff.
3.5 Chance 5 1
L TS 3.8.1.1 Action Statement "d"- Two offsite circuits inoperable The requirement to test the DGs for inoperable offsite circuits will be deleted to eliminate an
. unnecessary start of the DGs. This practice is consistent with GL 93 05 and NUREG-1432.
The statement that successful tests of the DGs for this action statement will satisfy the j
required test of Action Statement a or b is no longer necessary with the proposed changes previously discussed. Therefore, this sentence will be deleted.
These changes are acceptable to the staff.
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4 3.6 Chance 6 TS 3.8.1.1 Action Statement "e"- Two diesel oeneratore inoperable The statement that a successful test of the diesel generator for this action statement will satisfy the required test of Action Statement b is no longer necessary'with the proposed changos discussed previously. Therefore, this sentence will be deleted. This change is acceptable to the staff.
3.7 Chance 7 TS 3.8.1.1. SR 4.8.1.1.1 The words "Two physically independent circuits between the offsite transmission network and the switchyard" will be replaced by "Each required offsite circuit." The details concoming the offsite circuits, which are proposed to be eliminated, are still contained in the LCO. The Bases will also be expanded to discuss offsite circuits. Therefore, this wording change does not affect any technical aspect of this SR and is consistent with NUREG-1432. This change is acceptable to the staff.
3.8 Chance 8 TS 3.8.1.1. SR 4.8.1.1.2 The wording of the SR will be changed from "Each diesel generator" to "Each required diesel generator." This is an editorial change.
A footnote (*) will be added to apply to all DG surveillance starts. The footnote will allow an engine prelube before starting, which in tum will reduce unnecessary engine wear. This practice is consistent with GL 84-15 and NUREG-1432.
Both changes are acceptable to the staff.
3.9 Chance 9 TS 3.8.1.1. SR 4.8.1.1.2.a.2 Millstone Unit 2 does not specify acceptance criteria for frequency or upper limit for voltage in the 31-day test as required by the standard technical specif' ation. Instead, the existing TS c
calls for a DG test to verify that the DG starts at a 97 percent voltage and a 90 percent rated
- speed within 15 seconds. Millstone Unit 2 is not committed to Regulatory Guide (RG) 1.9, Revision 3. The licensee is committed to address the differences of the TS during the conversion to NUREG-1432, since NUREG-1432 is based on RG 1.9 Rev. 3.
The words " Verifying the diesel starts from ambient conditions" are replaced with the words
" Verifying the diesel starts from standby conditions." The Bases will be expanded to include the definition of " standby condition." This is consistent with NUREG-1432.
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5 The 31-day testing requirement for the DGs to start and obtain speed and voltage will be retained. The addition of the sentence "A modifed start involving idling and gradual acceleration to synchronous speed may be used as recommended by the manufacturer," will allow the use of a modified start. In a conference call with the licensee, the staff noted that NUREG-1432 includes specific requirements for when the modified start procedure is not used. Based on this discussion with the staff, in its February 11,1999, supplemental submittal the licensee agreed to add the following sentence "If a modified start, as just defmed, is not used, the requirements of Surveillanco Requirement 4.8.1.1.2.d.1 apply for the test." This is consistent witn NUREG-1432.
A footnots (") will be added to state that this SR can be satisfed by performance of SR 4.8.1.1.2.d. SR 4.8.1.1.2.d, which is proposed to be added for at least once per 184 days, is a more restrictive test of the DGs. Therefore, successful performance will meet the requirements of this SR. This is consistent with NUREG-1432. The list of acceptable methods to start the DGs for this SR will be added to the Bases of this specification.
These changes are acceptable to the staff.
3.10 Chance 10 TS 3.8.1.1. SR 4.8.1.1.2.a.3 The requirement to load the DG within 60 seconds will be deleted, instead, a statement will be added: " loaded in accordance with manufacturer's recommendations." This statement will allow gradual loading, on the basis of the manufacturer's recommendations. This change is consistent with GL 84-15, GL 93-05 and NUREG-1432.
A footnote (") will be added stating that this SR can be satisfied by performance of SR 4.8.1.1.2.d which is proposed to be added, a more restrictive test of the DG. Therefore, successful performance will meet the requirement of this SR. This practice is consistent with NUREG-1432.
These changes are acceptable to the staff.
3.11 Chance 11 TS 3.8.1.1. SR 4.8.1.1.2.b The standard referenced for diesel fuel oil sampling will be changed from American Society for Testing and Materials (ASTM) 270-65 to ASTM D4057. ASTM D270 was replaced by ASTM D4057 (manual sampling) and ASTM D4177 (automatic sampling). Millstone Unit 2 only performs manual sampling. The standard referenced for the acceptable Anits of the sample, ASTM D975-78, will be modified by deleting "78", which refers to either the year of adoption or the year of revision. Deleting the reference to the year will allow the latest revised standard to be used without requiring a TS change. This change will not affect the sampling frequency or the acceptance limits of this SR and is, therefore, acceptable to the staff.
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3.12 Chance 12 TS 3.8.1.1. SR 4.8.1.1.2.c j
j in its first submittal of July 17,1998, the licensee proposed to delete tha words "during shutdown" from the first sentence: "At least once per 18 months during shutdown." The s
licensee claimed the change was consistent with GL 93-04, which concluded that TSs need i
not restrict survedlance as only bemg performed during shutdown. However, GL 93-04 a!so added that " safety dictates that when refueling interval survedlances are performed during power operation, licensees give proper regard for their effect on the safe operation of the plant. If the performance of a refueling interval surveillance during plant operation would adversely affect safety, the I,consee should postpone the surveillance until the unit is shut down for refuelmg or is in a condition or a mode that is consistent with safe conduct of the surveillance." Additionally, NUREG-1432 specifically mentions not to perform any of the 18-month surveillances in Mode 1 and 2, and some of the surveillances at any Mcdes 1 through 4. Because of the contradictory statements in two different regulatory docaments, the staff has taken a consistent position that if any licensee wants to perform this 18-month surveillance during any other modes other than shutdown, a justification is needed to describe all compensatory measures to be taken and how these measures ensure plant safety for each of these surveillance in a telephone conference call with the licensee on November 4,1998, the staff conveyed its position regarding 18-month surveillance to be performed in any other mode than shutdown. In a letter dated November 10,1998, the licensee, after re-evaluating the need for this change, withdrew this proposed change.
3.13 Chance 13 TS 3.8.1.1, SR 4.8.1.1.2.c.5.b The wording of this SR will be changed from " verifying the diesel start from ambient conditions" to " verifying the diesel starts from standby conditions."
This change is consistent with NUREG-1432 and is therefore, acceptable to the staff.
3.14 Chanae 14 TS 3.8.1.1. SR 4.8.1.1.2.c.8.a The wording of this SR will be modified by adding "from standify conditions" after "the diesel generator starts." This change is consistent with NUREG-1432 and is therefore, acceptable to the staff.
3.15 Chance 15 TS 3.8.1.1 SR 4.8.1.1.2.d This SR will be added to test tne DGs every 184 days at conditions similar to the current 31-day SR which is discussed in Change 9.
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As is discussed in Change 9, Millstone Unit 2 does not speafy acceptance criteria for frequency or upper limit for voltage in the 184-day test as required by the standard teMnical 5
i specification. Instead, the existing TS calls for DG test to verify it starts at a 97 perca. voltage and a 90 percent rated speed within 15 seconds. In a conference call with the iicensee, the staff expressed concern that if the time for voltage and speed to stabilize was not monitored and trended then any degradation of govemor or voltage regulator performance would not be known. As a result of this discussion, in its February 11,1999, supplemental response the licensee agreed to add a paragraph to the Bases sechon stating that the time for voltage and speed to stabikze would be monitored and trended.
The words "Venfying the diesel starts from ambient conditions" are replaced with the words
" Verifying the diesel starts from standby conditions." The Bases will be expanded to include the definition of " standby condition." This is consistent with NUREG-1432.
The list of acceptable methods of starting the DGs for this SR will be added to the Bases for this TS.
This SR will require the DGs to start and obtain speed and voltage within 15 seconds. It will also require the DGs to be synchronized, loaded, and maintain the load for at least 60 minutes.
However, it will allow a gradual loading, based on manufacturer's recommendations, to be used. This is consistent with GL 84-15, GL 93-05, and NUREG-1432.
The addition of this SR is acceptable to the staff.
3.16 Chance 16 TS 3.8.1.2 (SHUTDOWN) LCO a The word " switchyard" will be changed to "onsite Class 1E distribution system." This is the same change proposed for TS 3.8.1.1 (OPERATING) LCO a, as previously discussed in Change 1. This change is consistent with NUREG-0212 and is therefore, acceptable to the staff.
3.17 Chaaos 17 TS 3.8.1.2. SR 4.8.1.2 The SR will be changed by adding SR 4.8.1.1.2.d.2 to the list of SRs that do not have to be performed for the operable DG in Modes 5 and 6. This measure is consistent with NUREG-1432 and is therefore, acceptable to the staff.
3.18 Chance 18 TS 3.8.1.1 and 3.8.1.2 Bases The Bases of these TS will be changed and expanded to discuss proposed changes and to provide guidance to ensure that the requirements are correct'y applied. The changes are acceptable to the staff.
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3.19 Evaluation Summarv l
The proposed changes will revise the DG TS SRs to achieve an overall improvement in DG reliability and availability. The proposed changes will modify the requirement for the DG operabihty testag when the other DG is inoperable, delete the requirement for DG operability testing when one or both offsite sources are inoperable, eliminate the fast loading of the DGs except for the 18 month test and eliminste fast starts (15 seconds) except for once every 6 months and during 18-month tests. The changes are consistent with GL 84-15, GL 93-05, NUREG-0212, and NUREG-1432. Since the proposed changes do not involve any modification to the physical plant and do not involve a significant increase in the probability or consequences of an acadent previously evaluated or created the possibility of a new or different kind of accident from any previously evaluated, the staff concludes that the proposed TS changes are consistent with other provisions of the existing TS and their technical bases.
4.0 STATE CONSULTATION
in accordance with the Commission's regulations, the Connecticut State offlcial was notified of the proposed issuance of the amendment. The State official had no comments.
5.0 ENVIRONMENTAL CONSIDERATION
The amendment changes requirements with respect to installation or use of a facility component located within the restricted area, as defined in 10 CFR Part 20, and changes surveillance requ:rements. 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 comment on such finding (63 FR 43207, August 12,1998). 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.
6.0 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.
Principal Contributor. S.K. Mitra Date: March 12, 1999