ML20034G452
| ML20034G452 | |
| Person / Time | |
|---|---|
| Site: | Cooper  |
| Issue date: | 03/02/1993 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20034G446 | List: |
| References | |
| NUDOCS 9303090532 | |
| Download: ML20034G452 (6) | |
Text
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NUCLEAR REGULATORY COMMISSION e
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-t WASHINGTON D. C. 20555 E
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION l
RELATED TO AMENDMENT NO.158 TO FAClllTY OPERATING LICENSE NO. DPR-46 NEBRASKA PUBLIC POWER DISTRICT COOPER NUCLEAR STATION l
DOCKET NO. 50-298
1.0 INTRODUCTION
By letter dated May 4,1992 (Reference 1), as supplemented by letters dated October 15, 1992 (Reference 2), January 13, 1993 (Reference 4), February 12, 1993 (Reference 8), and February 24,1993 (Reference 9), Nebraska Public Power District (the District, NPPD, or the licensee) submitted a request for an amendment authorizing the removal of the Main Steam Line Radiation Monitor (MSLRM) reactor scram and Group I Containment Isolation functions, and modifying the Technical Specifications (TS) for Cooper Nuclear Station (CNS) accordingly.
Specifically, this amendment will make the following changes to the TS.
(1)
References to Main Steam Line Radiation Monitor RMP-RM-251 A, B, C, and l
D are removed from TS Table 3.1.1, " Reactor Protection System l
Instrumentation Requirements," TS Table 4.1.1, " Reactor Protection System (Scram Instrumentation) Functional Tests, Minimum Functional Test frequencies for Safety Instrumentation and Control Circuits," and TS Table 4.1.2, " Reactor Protection System (Stram) Instrument Calibration Minimum Calibration Frequencies For Reactor Protection
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Instrument Channels."
(2)
Action Statement "D" is removed from TS Table 3.1.1.
l (3)
Note 4 is deleted from TS Table 4.1.1.
(4)
Note 3 is deleted from TS Table 4.1.2.
(5)
The discussion in TS Bases 3.1 relating to reactor scram on high MSLRM signal is deleted.
(6)
A new Action Statement "E" is added to TS Table 3.2. A, " Primary Containment and Reactor Vessel Isolation Instrumentation," to require isolation of the Reactor Water Sample Valves (Group 7) if the MSLRM becomes inoperable.
Also, MSLRM is removed from the Group 1 Containment isolation signal list in Table 3.2. A.
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(7)
Minor editorial changes are made to Action Statement "E" of TS Table 3.2.D, " Radiation Monitoring Systems That Initiate And/0r Isolate Systems."
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Surveillance requirements of the MSLM are added to TS Table 4.2. A,
" Primary Containment and Reactor Vessel 1 solation System Test and Calibration Frequencies."
(9)
References in TS Table 4.2.D, " Minimum Test and Calibration-Frequencies For Radiation Monitoring Systems," to surveillance requirements l
associated with the Mechanical Vacuum Pump isolation (provided by the MSLRM) in TS Tables 4.1.1 and 4.1.2 are changed to TS Table 4.2. A to reflect the relocation of MSLRM surveillance requirements from Tables 4.1.1 and 4.1.2 to Table 4.2.D.
(10)
Note 5 to TS Tables 4.2. A through 4.2.F is revised to delete reference to the MSLRM.
New notes 13 and 14 have been added to address MSLRM surveillance requirements.
(11)
TS Bases 3.2 has been revised to reflect the removal of the Main Steam l
Isolation Valve (MSIV) closure function from the MSLRM.
i The plant modifications authorized by this amendment will provide a number of operational benefits, while improving radiological release management l
associated with the Control Rod Drop Accident (CRDA).
The October 15, 1992, and January 13, February 12, and February:24, 1993, NPPD letters provided clarifying information that did not change the initial proposed no significant i
hazards consideration determination published in the Federal Register on July 8, 1992, at 57 FR 30252.
2.0 DISCUSSION j
i Boiling Water Reactors (BWRs) are equipped with radiation monitors which are located on the main steam lines downstream from the main steam isolation valves (MSIVs). The MSLRMs detect moderate-to-large fuel failures and close the MSIVs to stop the release of radioactivity into the steam lines.
On detection of high radiation in the main steam line, trip circuits automatically shut dowr. the reactor and close the MSIVs.
i On July 9, 1987 (Reference 5), the Boiling Water Reactor Owner's Group (BWROG) requested that the NRC staff review NEDD-31400 (Reference 6), a topical report prepared by the General Electric Company, which evaluated the elimination of the MSIV closure function and reactor scram function of the MSLRM.
NED0-31400 j
showed that the radiological release consequences of the bounding accident (the CRDA) are within the NRC st6ff's acceptance criteria even without the automatic MSIV closure and reactor trip.
The NRC staff reviewed NED0-31400 and concluded that the proposed cnanges were acceptable.
However, the staff's
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generic approval of NED0-31400 imposed three additional requirements which must be met by licensees desiring to implement the proposed changes for j
specific plants. The NRC staff's safety evaluation of NEDD-31400 and the additional staff requirements were provided in Reference 7.
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The additional requirements that must be met by licensees are:
(1)
The licensee must demonstrate that the assumptions with regard to input i
values (including power per assembly, Chi /Q, and decay times) that are made in the generic analysis bound those for the plant.
(2)
The licensee must include sufficient evidence (implemented or proposed operating procedures, or equivalent commitments) to provide reasonable assurance that increased significant levels of radioactivity in the main steam lines will be controlled expeditiously to limit both occupational doses and environmental releases.
(3)
The licensee must standardize the MSLRM and of fgas radiation monitor alarm setpoints at 1,5 times the nominal nitrogen-16 background dose rate at the monitor locations, and commit to promptly sample the reactor coolant to determine possible contamination levels in the plant reactor coolant and the need for additional corrective actions, if the MSLRM or offgas radiation monitors, or both, exceed their alarm setpoints.
3.0 EVALUATION The CNS licensee has proposed several changes to the T5 to implement the deletion of the MSLRM containment isolation and reactor trip functions, and to meet the three additional requirements imposed by Reference 7.
With regard to requirement (1) of Reference 7, the licensee provided, in l
i Reference 4 (as corrected by Reference 9), a table comparing the key input assumptions used in NED0-31400 and those used for the CNS analysis. The staff has reviewed the table and finds that it' provides an acceptable demonstration that the CNS CRDA analysis is bounded by the assumptions used in the generic analysis of NED0-31400. On this basis the NRC staff concludes that requirement (1) of Reference 7 has been met.
With regard to requirement (2) of Reference 7, the licensee provided,'in Reference 4, a discussion of the existing procedures and procedural' changes i
that will be made to assure that expeditious actions will be taken to minimize both occupational exposure and environmental releases during periods when increased coolant activity is experienced. The NRC staff has reviewed the licensee's discussion of plant procedures and procedural changes and concludes that it is acceptable.
On this basis the staff finds that requirement (2) of Reference 7 has been met.
With regard to requirement (3) of Reference 7, the licensee stated in Reference 4 that the MSLRM high alarm setpoint will be retained at 1.5 times background, and the offgas radiation monitor high alarm will be set at slightly greater than 1.5 times background. The offgas radiation monitor alarm will be set slightly above 1.5 times background in order to avoid nuisance alarms in the control room while performing weekly grab sampling or monthly source checks.
In Reference 4, the licensee provides a description of I
the operator actions to be taken following high and high-high alarms from the
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-; i MSLRM or offgas radiation r e itor. The actions include prompt sampling of the reactor coolant following a Ligh alarm. The NRC staff has reviewed the i
licensee's commitments regarding standardizing the MSLRM and offgas radiation monitor alarm setpoints and prompt sampling of reactor coolant on an. alarm and finds them acceptable. On this basis the staff concludes that requirement (3) of Reference 7 has been adequately met.
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In summary, the NRC staff has reviewed the proposed TS changes to implement i
removal of the MSLRM Reactor Scram and Group 1 Containment Isolation closure functions. The NRC staff has previously reviewed and found acceptable the l
generic topical report prepared by the General Electric Company for implementing these changes. The staff safety evaluation is documented in Reference 7.
The staff approval of these changes for specific plants is conditional on the licensee meeting the three additional requirements defined in Reference 7.
The staff review of the proposed changes to the CNS TS concludes that the licensee's application and the proposed changes meet the three additional requirements. Accordingly, the proposed TS changes discussed in References 1, 2 and 4 are acceptable to the staff and are hereby approved.
4.0 STATE CONSULTATION
l In accordance with the Commission's regulations, the Nebraska State official was notified of the proposed issuance of the amendment.
The State official i
had no comment.
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5.0 ENVIRONMENTAL CONSIDERATION
The amendment changes a requirement with respect to installation or use of a i
facility component located within the restricted area as defined in 10 CFR Part 20 and changes in surveillance requirements. 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 t
occupational radiation exposure. The Commission has previously issued a pro-posed finding that the amendment involves no significant hazards. consideration and there has been no public comment on such finding (57 FR 30252).
i Accordingly, the amendment meets the eligibility criteria for categorical l
exclusion set forth in 10 CFR Section 51.22(c)(9).
Pursuant to 10 CFR 51.22(b) no environmental impact statement or environmental assessment need be
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prepared in connection with the issuance of the amendment.
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6.0 CONCLUSION
The Commission has concluded, base,on the considerations discussed above, that: (1) there is reasonable assi rance that the health and safety of the i
public will not be endangered by o,eration 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.
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7.0 REFERENCES
I (1)
Letter and enclosures from G. R. Horn, Nebraska Public Power District, f
to USNRC, dated May 4, 1992, " Proposed Change No. 100 to Technical Specifications, Elimination of Main Steam Line Radiation Monitor Scram and Isolation Functions, Cooper Nuclear Station, NRC Docket No. 50-298, DPR-46."
i (2)
Letter and enclosures from G. R. Horn, Nebraska Public Power District, to USNRC, dated October 15, 1992, " Revision to Proposed Change No. 100 to Technical Specifications, Elimination of Main Steam Line Radiation Monitor Scram and Isolation functions, Cooper Nuclear Station, NRC Docket No. 50-298, DPR-46."
(3)
Letter from H. Rood, NRC, to G. R. Horn, Nebraska Public Power District, dated December 1, 1992, " Request for Additional Information (RAl) Related to Proposed Change No. 100 to the Cooper Nuclear Station Technical Specifications, Elimination of Main Steam Line Radiation Monitor Scram and Isolation Functions (TAC No. 83768)."
(4)
Letter from G. R. Horn, Nebraska Public Power District, to USNRC, dated sanuary 13, 1993, " Response to Request for Additional Information Related to Proposed Change No.100 to Technical Specifications,
' Elimination of Main Steam Line Radiation Monitor Scram and Isolation Functions,' (LAC No. M83768), Cooper Nuclear Station, NRC Docket No.
50-298, DPR-46."
(5)
Letter and enclosures from R. Janeck, BWR Owner's Group, to J. Funches, NRC, dated July 9,1987, requesting an NRC review of the generic Topical Report NEDO-31400.
(6)
NED0-31400, " Safety Evaluation of Eliminating the Boiling Water Reactor Main Steam Line Isolation Valve Closure function and Scram function of the Main Steam Line Radiation Monitor," the General Electric Company, May 1987.
(7)
Letter and enclosures from A. Thadani, NRC, to George J. Beck, Chairman, BWR Owner's Group, dated May 15, 1991, " Acceptance for Referencing of Licensing Topical Report NE00-31400, ' Safety Evaluation for Eliminating the Boiling Water Reactor Main Steam Line Isolation l
Valve Closure Function and Scram function of Main Steam Line Radiation Monitor.'"
(8)
Letter and enclosures from G. R. Horn, Nebraska Public Power District, to USNRC, dated February 12,1993, " Submittal of Pages Inadvertently Omitted from Proposed Change No.100 to Technical Specifications,
' Elimination of Main Steam Line Radiation Monitor Scram and Isolation J
Functions,' Cooper Nuclear Station, NRC Docket No. 50-298, DPR-46."
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(9)
Letter from G. R. Horn, Nebraska Public Power District, to USNRC, dated February 24,1993, " Correction to Response to Request for Additional Information Regarding Proposed Change No. 100 to Technical Specifications Elimination of Main Steam Line Radiation Monitor Scram 1
and Isolation functions, Cooper Nuclear Station, NRC Docket No. 50-298, DPR-46 "
i Principal Contributor:
H. Rood j
Date:
March 2, 1993 I
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