ML20236V315
| ML20236V315 | |
| Person / Time | |
|---|---|
| Site: | Monticello  |
| Issue date: | 11/25/1987 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20236V304 | List: |
| References | |
| NUDOCS 8712040227 | |
| Download: ML20236V315 (4) | |
Text
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UNITED STATES -
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WASHINGTON, D. C. 20656
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SAFETY EVALUATION BY THE OFFICE OF' NUCLEAR REACTOR' REGULATION.
RELAltD TO AMENUMENT NO. 55 TO FACILITY OPERATING LICEN5L NO. DPR-22 NORTHERN STATES POWER COMPANY a
.MONTICELLO NUCLEAR GENERATING PLANT DOCKET NO. 50-263 1
1.0 _INTPCDUCTION By letter dated May 1,1986, as supplemented July 15 'and October 7,1987,.
i Northern States Power. Company (the licensee) requested an amendment to Facility' Operating License No. OPR-22 for the Monticello Nuclear Generating Plant. The anendment request proposed the following changes to the Technical. Specifications 1
(TS) concerned with the containment system.
1 1.
Revise the wording of TS Section 4.7.A.2, " Primary Containment Integrity "
4 and associated bases to conform to the wording of NRC Standard TS-
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(NUREG-0123);
2.
Change the airlock testing requirements for Type [B testing; 3.
Increase the TS value of Pa, Peak Containment Accident Pressure, from 41 psig to 42 psig; 4.
Delete the requirement for inerting system makeup monitoring as specified in Section 4.7.A.2.6;
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Revise the Bases for Sections 3.7 and 4.7 to.reflectLthe above changes; and 6.
Add Action Statements consistent with NUREG-0123 to TS Section'3.7.A.2 on 1
containment integrity limiting condition for operation. -
The July 15 and October 7,1987 submittels contained additional information or clarified the changes requested and did not substantially alter the action noticed, or affect the staf f's initial determination in the Federal Register on August 16, 1986.
2.0 EVALUATION 1.
Revised Wording of TS Section 4.7. A.2 (paragraphs 4.7. A.2.b.4.c and 4.7.A.2.b.4.d)
The licensee proposes to revise the wording of TS Section 4.7.A.2 to confonn to the wording of General Electric Standard Technical.Speci-fications. The staff has reviewed the licensee's revisions'and finds them acceptable. Specifically, in the case of paragraph 4.7.A.2.b.4.c j
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dealing with the rate 'of gas injected into containment, by letter dated October 7, 1987, the licensee clarified the requirement recarding the limitation of the gas to be injected between 75 and 125% of La. By letter dated July 15, 1987, the licensee relocated the contents of
'l paragraph 4.7.A.2.b.5 to 4.7. A.2.b.4.d and specified that the test interval for Type B and C tests and the main steam isolation valves shall be conducted at each refueling outage. The lionsee did not-specify the test interval for the feedwater isolation valves as previously suggested by the staff. The licensee stated that the 7eedwater isolation valves are tested in accordance with Type C test requirements as spec'ified in Appendix J to 10 CFR Part 50. The staff finds that the feedwater isolation valves do not have valve leakage collection systems and the test can be performed at 24-month Type C test intervals as _ required for all the containment isolation valves. Therefore, it is acceptable not to specify leak rate test frequencies for the feedwater isolation valves.
On this basis, the staff finds the changes to paragraphs 4.7.A.2.b.4.c and 4.7.A.2.b.4.d acceptable, j
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2.
Revision to TS 4.7.A.2.c - Airlock Testing Requirements By letter dated October 7, 1987, the licensee submitted a revision to the Technical Specification, deleting testing of the airlock at reduced pres-
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sure which had been previously proposed in paragraph 4.5.C.I.
The licensee's I
revision to paragraph 4.5.C.1 also included the provision to extend the test
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interval up to the next refueling outage (up to a maximum interval of 24
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months) if there have not been airlock openings since the last successful I
test at Pa. The licensee stated that an exemption from Appendix J require-I ments for extending the 6-month airlock test' interval was previously granted l
by NRC in a letter dated June 3,1984' The staff has examined the NRC's j
Appendix J exemption document and finds that the proposed statement in TS 4.5.C.1 conforms to the exemption as granted. On this basis, the staff finds-l the licensee's proposed TS changes acceptable. However, any maintenance or repair of the airlock should be considered as an airlock opening and should not be included in the Appendix J test interval exemption.
4 3.
Increase desion basis accident pressure Pa from 41 to 42 psig The licensee increased the TS value of Pa from 41 psig to 42 psig because of the new GE containment response calculations. GE has assumed additional break area of the RHR intertie line installed in 1984, yielding a peak accident pressure of 42 psig when rounded off to the nearest Psi. The licensee has submitted a GE analysis report entitled Monticello Design Basis Accident Containment Pressure and Temperature Response for FSAR Update." The licensee stated that all future testing will be performed l
at the higher pressure. The staff has reviewed the GE report and finds l
the increased Pa acceptable since the new containment response analysis l
1s based on a plant modification and is conservative for use as the leak i
testing pressure. The licensee should review'all leak test acceptance criteria based on the new Pa value.
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. 4.
Delete TS Section 4.7.A.2.6 requirements for inerting system makeup monitoring The licensee proposes to delete the monitoring requirements for the nitrogen makeup line. The licensee states that this specification is based on a false hypothesis that monitoring makeup flow into the containment would detect significant changes in containment leakage.
Fourteen years of plant operating experience has proven this requirement to be impractical. The licensee concludes that this is not a requirement of the GE Standard Technical Specifications and proposes to delete it.
The staff concurs with the licensee's decision because the snell amount of makeup flow to the containment could not be used to monitor low leak-l age out of containment at the low differential pressure between the inside l
and outside of the drywell during normal operation. Therefore, deleting TS 4.7.A.2.6 requirements for inerting. system makeup monitoring is accept-
- able, f
5.
Revision of Bases for Sections 3.7.A and 4.7.A of the TS In section 3.7.A. the licensee has changed containment pressure to 42 psig and updated the FSAR reference.
In section 4.7.A, the licensee has proposed to change checks of the suppression chamber temperature and volume from weekly to daily to ensure that these parameters are within their allowable j
ranges, delete a paragraph concerning primary containment preoperational test pressure as described in Section 5.2.3 of the FSAR, and change contain-ment maximum allowable accident leak rate from 1.5 wt.% per day to 1.2% on NRC offsite dose analyses. These revisions are to reflect the above described 1
changes and to update the TS and, therefore, are acceptable.
6.
Add Action Statements for Section 3.7.A.2 of the TS l
The licensee proposes to add the Action Statements using a format similar to Section 3.6.1.2 of the GE Standard Technical Specifications, which provides the bases for containment leakage rate measurement. The staff has reviewed the bases contained in the Action Statements and finds them acceptable.
3.0 ENVIRONMENTAL CONSIDERATION
l This amendment involves a change to a requirement with respect to the installa-tion or use of a facility component located within the restricted area as definec in 10 CFR Part 20 or changes surveillance requirements. The staff has determined that the amendment involves no significant increase in the amounts, and no signif-icant 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 i
exposure. The Commission has previously issued a proposed finding that this l
amendment involves no significant hazards consideration and there has been I
no public coment on such finding. Accordingly, this 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 this amendment.
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4.0 CONCLUSION
The staff has concluded, based on the considerations discussed above, that:
(1) there is reasonable assurance that the health and safety of the will not be endangered by operation in the proposed manner; and (2) public
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activities will be conducted in compliance with the Commission's regulations' l
and the issuance of this arnendment will not be inimical to the common defense
.l and security or to the health and safety of the public.
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Principal Contributors:
J. S. Guo and D. C. Dilanni Dated: November 25,~1987 l
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