ML20205B335
| ML20205B335 | |
| Person / Time | |
|---|---|
| Site: | Prairie Island  |
| Issue date: | 03/17/1999 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20205B328 | List: |
| References | |
| NUDOCS 9903310220 | |
| Download: ML20205B335 (4) | |
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NUCLEAR REGULATORY COMMISSION 2
WASHINGTON, D.C. 'annan anni
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i SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION l
RELATED TO AMENDMENT NO. 143 i
~ TO FACILITY OPERATING LICENSE NO. DPR-42 AND AMENDMENT NO.134 TO FACILITY OPERATION LICENSE NO. DPR-60 NORTHERN STATES POWER COMPANY PRAIRIE ISLAND NUCL EAR GENERATING PLANT. UNITS 1 AND 2 DOCKET NOS. 50-282 AND 50-306
1.0 INTRODUCTION
By letter dated November 25,1998, Northem States Power Company (NSP, the licensee) requested an amendment to the Prairie Island Nuclear Generating Plant (PINGP) Units 1 and 2 Operating Licenses that would authorize changes to the Technical Specification (TS) for the boric acid storage tank (BAST) level instrumentation and transfer logic.
l The PINGP TSs currently require monthly operability testing of the BAST transfer logic associated with the transfer of safety injection pump suction from the BAST to the refueling water storage tank (RWST). ' To perform this required testing, individual BAST level anu transfer logic channels must be made inoperable. However, the TSs do not permit inoperability of those channels for performing the required testing. The proposed TS changes would permit limited inoperability for performing these tests.
2.0 EVALUATION The licensee proposed changes to the following TSs:
a.
TS 3.2.B The licensee proposed a revision to TS 3.2.B to reference revised Table TS.3.5 2B
' which contains actions required in ene of inoperability of the instrumentation required to be operable by TS 3.2.B.5, for transfen?ng safsty injection pump suction from the BAST to the RWST.
b.
Table TS.3.5-2B Functional Unit 9a, B/.ST Lo-Lo Level The licensee proposed a revision b Table TS.3.5-2B to add Functional Unit 9a, BAST Lo-Lo Level. Functional Unit 9a provides the requirements for operability of the BAST lo-lo level function. The proposed TS total number of channels for lo-lo level operability 9903310220 990317 PDR ADOCK 05000282 P
PDR 2
u 2-is 2 with 2 sensors per channel. The number of sensors required to activate the BAST to RWST transfer is 1 per channel. The proposed TS minimum number of sensors j
required to be operable per channel is 2. The proposed TS requn 9d number of operable channels for this functional unit is consistant in format an:f number with other instrumentation in current Table TS.3.5-28 with similar logic configurations. The
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proposed TS applicable operability modes,1,2,3, and 4, are the same as those specified for the transfer logic in TS 3.2.B.5.
c.
Table TS.3.5-28, Action 34 Proposed Action 34 specifies that with the number of operable channels less than the total number of channels, operation may proceed provided the inoperable channel is placed in the tripped condition within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />. Placing an inoperable channel in the tripped condition ensures that if the BAST to RWST transfer becomes necessary, the inoperable channel will not prevent the transfer. The 6-hour allowance for completion of this action allows adequate time for personnel to complete tripping of the channel, while minimbing the time and associated risk that the transfer functinn could be defeated by an inoperable channel during an event. The proposed requirement to place an inoperable channel in the tripped condition within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> is consistent with the actions specified for other similar instrumentation in current Table TS.3.5-28.
Proposed Action 34 also specifies a 72-hour limitation on operation with an inoperable BAST level channel. This 72-hour allowance limits the risk from a premature transfer from the BAST to the RWST while providing time for testing and repair or replacement
. of failed components. The 72-hour allowance for operation with an inoperable BAST level channel is comparable to the allowed out-of-service time specified in TS 3.2.C.5 1
and TS 3.3.A.2 for related BAST and RWST valves. The effect of continued operation with an inoperable BAST level channel is comparable to that associated with continued operation with an inoperable BAST supply valve and RWST supply valve.
Proposed Action 34, additionally, requires that if the inoperable BAST level channel cannot be restored to operable status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, the unit must be brought to at 4
least hot shutdown within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and to cold shutdown within the following 30
- i hours. These are standard shutdown times utilized throughout the licensee's current TSs.
d.
Table TS.3.5-28, Functional Unit 9b - BAST Automatic Actuation l'ogic and Actuation Relays The licensee proposed a revision to Table TS.3.5 RB to add Functional Unit 9b, BAST Automatic Actuation Logic and Actuation Relays. Functional Unit 9b provides the requirements for the operability of the BAST to RWST transfer logic and actuation relay channels. The proposed TS required total number of operable channels is 2. The
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number of channels required to actuate the BAST to RWST transfer is 1. The proposed i
TS required operable channels for this functional unit are consistent in format and number with other actuation logic channels in current Table TS.3.5-2B. The proposed
.TS applicable operating modes,1,2,3, and 4, are the same as those specified for the
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transfer interlocks in TS 3.2.B.S.
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Table TS.3.5-2B, Action 35 Proposed Action 35 allows continued operation for 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> with an inoperable logic i
channel. The 72-hour allowance limits the time and associated risk incurred from operating with an inoperable logic channel while praviding time for testing and repair or replacement of failed components. The 72-hour allowance for operation with an inoperable BAST to RWST logic channel is compa:able to the allowed out-of-service times specified in TS 3.2.C.5 and TS 3.3.A.2.d for related BAST and RWST valves.'
Proposed Action 35 also requires that if the inoperable logic channel cannot be restored
. to operable status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, the unit must be brought to at least hot shutdown within the nest 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and to cold shutdown within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />. These are standard shutdown times utilized throughout the licensee's current TSs.
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Table TS.3.5-2B, Action 36 Proposed Action 36 allows continued operation for 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> with both BAST and RWST i
transfer logic channels inoperable for surveillance testing. The 1-hour allowance limits the time and associated risk incurrer from operation with both logic channels j
inoperable, while providing time for testing of the logic channels. The proposed 1-hour allowed outage time is comparable to the time allowed by the licensee's current TSs for l
the loss of function of other systems.
l g.
Bases 3.5, Instrumentation System The proposed revision to TS Bases 3.5, " Instrumentation System" incorporates descriptions related to the proposed changes to TS 3.2.B and Table TS.3.5-2B and describes the automatic transfer of safety injection pump suction from the BAST to the p
RWST.
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The staff finds that the above proposed TS changes provide appropriate limiting conditions for i
operation ar'd action statements for operability of BAST lo-lo level instrumentation and for logic j
instrumentation for transfer of safety injection pump suction from the BAST to the RWST.
j Based on the above evaluation, the staff concludes that the proposed changes to the Prairie i
Island TS to allow limited inoperability of the BAST level instrumentation and BAST to RWST j
transfer logic instrumentation are consistent with the current Prairie Island TSs for instrumentation performing similar safety functions and are, therefore, acceptable,
3.0 STATE CONSULTATION
in accordance with the Commission's regulations, the Minnesota State official was notified of
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the proposed issuance of the amendments. The State official had no comments.
4.0 ENVIRONMENTAL' CONSIDERATION i
The amendments change a requirement with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20 and change 4
j surveillance requirements. The NRC staff has determined that the amendments involve no p
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l 1 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 incre'se in individual or cumulative l
occupational radiation exposure. The Commission has previously issued a proposed finding that the amendments involve no significant hazards consideration and there has been no public comment on such finding (63 FR 69345). Accordingly, the amendments meet 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 amendments.
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 amendments will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributor:
B. Marcus Date: March 17, 1999 1
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