ML20137W192
| ML20137W192 | |
| Person / Time | |
|---|---|
| Site: | Monticello  |
| Issue date: | 04/11/1997 |
| From: | Hill W NORTHERN STATES POWER CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20137W196 | List: |
| References | |
| TAC-M96256, NUDOCS 9704180053 | |
| Download: ML20137W192 (3) | |
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1 Northem States Power Company Monticello Nuclear Generating Plant 2807 West Hwy 75 1
Monticello, Minnesota 55362 9637
/
April 11,1997 10 CFR Part 50 Section 50.90 U S Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555 i
1 MONTICELLO NUCLEAR GENERATING PLANT Docket No. 50-263 License No. DPR-22 Revision One to License Amendment Request Dated July 26,1996 Reactor Coolant Eauivalent Radioiodine Concentration and Control Room Habitability (TAC M96256)
Attached is a revision to our July 26,1996 license amendment request which proposed 4
changes to the Technical Specifications, Appendix A of the Operating License, for the Monticello Nuclear Generating Plant. This request is submitted in accordance with the provisions of 10 CFR Part 50, Section 50.90. This revision supersedes in its entirety our submittal dated July 26,1996. Changes to our July 26,1996 submittal are indicated by revision bars in the margins of Exhibits A, D and E.
This proposed amendment changes Technical Specification sections 3.6.C, Coolant Chemistry, and 3/4.17.B, Control Room Emergency Filtration System. In addition, changes are submitted for the bases for these sections. The changes were proposed to establish Technical Specification requirements consistent with modified analysis inputs used for the evaluation of the radiological consequences of the Main Steam Line Break Accident. This revision to our license amendment request dated July 26,1996, proposes to revise the reactor coolant radiciodine concentration specified in Technical Specification section 3.6.C, Coolant Chemistry in response to evaluations performed of the radiological consequence of a postulated line break in the Reactor Water Cleanup (RWCU) system.
I As reported in Monticello Licensee Event Report (LER)96-008, " Reactor Water Clean Up Line Break Reanalysis Due to an Error Discovered During Re-evaluation," a discrepancy in the mass f
and energy release calculated for a postulated high energy line break (HELB) in the Reactor Water Cleanup (RWCU) piping has been identified. As part of the corrective actions to address this issue, a justification for continued operation for plant operation with the RWCU system in j
service was prepared and an administrative limit of 0.25 Cl/gm for the reactor coolant dose j
i equivalent radiolodine concentration was established. This administrative limit provides appropriate limits on the radiological sourcs term to assure that for a postulated HELB in the f
i RWCU piping, the radiological consequences remain bounded by those of a postulated Main Steam Line Break as analyzed in the Atomic Energy Commission Safety Evaluation Report, issued March 18,1970, in support of the Monticello Provisional Operating License. Submittal of l
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l t 5 t f USNRC NORTHERN STATES POWER COMPANY April 11',1997 Page 2 this license amendment request revision satisfies the action committed to in LER 96-008 to l submit a change to the Technical Specifications to establish the administrative limit on reactor coolant dose equivalent radioiodine concentration as a Technical Specification Limiting Condition for Operation. The analysis of the postulated RWCU HELB dose consequences, as summarized in Exhibit E, was performed using an input assumption for reactor coolant dose equivalent radioiodine of 0.25 pCi/gm This proposed change to the reactor coolant dose equivalent radiciodine concentration is an interim change to address the issue reported in LER 96-008. As reported in LER 96-008, Monticello is pursuing the evaluation of plant modifications to provide automatic isolation of postulated RWCU HELBs. It is expected upon completion of the plant modification evaluation and design, that the design analyses will support a reactor coolant dose equivalent radioiodine concentration of 2 Ci/gm. The analysis of the postulated Main Steam Line Break summarized in Exhibit D was performed using an input of 2 pCi/gm for the reactor coolant dose equivalent radiciodine concentration. Retaining the analysis input of 2 Ci/gm for the evaluation of the postulated Main Steam Line Break Accident demonstrates that the change proposed herein to I the specification for reactor coolant dose equivalent radiciodine is conservative with respect to the evaluation of the postulated Main Steam Line Break Accident, while retaining intact this analysis to support the future planned submittal to establish the Technical Specification limit for reactor coolant dose equivalent radioiodine concentration at 2 pCi/gm. Exhibit A contains a description of the proposed changes, the reasons for requesting the changes, a Safety Evaluation, a Determination of Significant Hazards Consideration, and an Environmental Assessrnent. Exhibit B contains the current Technical Specification pages marked up with the proposed changes. Exhibit C contains revised Monticello Technical Specification pages. Exhibit D,"MNGP MSLBA Analysis Summary," provides a summary of the modified Main Steam Line Break analysic and reports the results of the re-evaluation of this postulated accident scenario. Exhibit E,"MNGP RWCU Evaluation Summary," provides a summary of the evaluation performed of the radiological consequences of a postulated line break in the RWCU system. Please contact Marvin Engen, Sr Licensing Engineer, (612-295-1291)if you require further information related to this request. l HEN n h4 William J Hill Plant Manager Monticello Nuclear Generating Plant c: See next page
.._...__.-_.__.m I 5 1 USNRC NORTHERN STATES POWER COMPANY April 11,1997 Page 3 c: Regional Administrator-lll, NRC ) NRR Project Manager, NRC I Resident inspector, NRC State of Minnesota Attn: Kris Sanda Attachments: Affidavit to the US Nuclear Regulatory Commission Exhibit A - Evaluation of Proposed Changes Exhibit B - Proposed Changes Marked Up on Existing Technical Specification Pages Exhibit C - Revised Monticello Technical Specification Pages Exhibit D - MNGP MSLBA Evaluation Summary i Exhibit E - MNGP RWCU Evaluation Summary i I 1 l-I i i I 1 d E}}