ML20246P829

Submits Revised Primary Coolant I-131 Concentration Limit. Administrative Limit Revised from 0.8 Uci/Ml I-131 to More Conservative Limit of 1.0 Uci/Ml Dose Equivalent I-131

ML20246P829
Person / Time
Site:	Rancho Seco
Issue date:	02/13/1989
From:	Croley B SACRAMENTO MUNICIPAL UTILITY DISTRICT
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
AGM-NTS-89-016, AGM-NTS-89-16, GL-85-02, GL-85-2, NUDOCS 8903280327
Download: ML20246P829 (4)

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• u. SACRAMENTO MUNICIPAL UTILITY DIST AN ELECTRIC SYSTEM SERVING THe HEART OF CALIFORNIA February 13, 1989 AGM/NTS89-016

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U. S. Nuclear Regulatory Commission 1 l Attn: Document Control Desk i Hashington, DC 20555 Docket No. 50-312 'l Rancho Seco Nuclear Generating Station j License No. DPR-54 REVISED PRIMARY COOLANT IODINE LIMIT CODMITMENT Attention: George Knighton The District's response to Generic Letter 85-02,' dated June 11, 1985, committed to administrative 1y implement a primary coolant Iodine-131 concentration limit of 0.8 pCi/ml. Clarification of the primary coolant j

l Iodine-131 concentration limit commitment and-its implementation is provided below. Specifically, the administrative limit is revised from 0.8 pCi/ml Iodine-131 to a more conservative limit of 1.0 pCi/ml Dose Equivalent Iodine-131 (DEI-131).

The B&W Standard Technical Specifications (NUREG-0103) provide guidance for the implementation of a primary coolant DEI-131 concentration limit. Limiting

, Condition for Operation 3.4.9 in NUREG-0103 specifies a 1.0 pCi/ml DEI-131 l limit and associated actions for plant operations above Hot Shutdown and a l 30-day reporting requirement if this DEI-131 limit is exceeded. NRC Generic Letter 85-19, dated September 27, 1985, modified the reporting requirement if.

the 1.0 pCi/ml DEI-131 limit is exceeded and eliminated the Standard Technical Specifications requirement to shut down a plant if the primary coolant DEI-131 limit is exceeded for 800 hours0.00926 days <br />0.222 hours <br />0.00132 weeks <br />3.044e-4 months <br /> in a 12-month period.

Specific types of analysis results are identified for inclusion in,the report, and' fuel burnup data by core region is no longer required. Also, the reporting requirement is reduced from a short term report (30-day)-to an annual report.

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RANCHO SECO NUCLEAR GENERATING STATION O 14440 Twin Cities Road, Herald, CA 95638-9799;(209)-333-2935 L

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George Knighton AGM/NTS89-016 l Revision 1 to procedure RSAP-0222 " Rancho Seco Chemistry Control Commitment" addresses the implementation of the revised administrative primary coolant DEI-131 limit, important aspects of which are discussed below:

• Hith the specific activity of the primary coolant greater than 1.0 pCi/ml DEI-131, but within the allowable limit shown on the attached figure (DEI-131 primary coolant concentration vs. percent thermal power), power operation may continue for up to 48 consecutive hours.

• Hith the specific activity of primary coolant greater than 1.0 pCi/ml DEI-131 for greater than 48 consecutive hours or exceeding the primary coolant DEI-131 limit line shown on the attached figure, be in Hot Shutdown within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.

• Hith the results of a specific activity analysis in excess of 1.0 pC1/ml DEI-131, include the following information in an annual report:

l (1) Reactor power history for the 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> prior to the first sample which indicated the DEI-131 limit was exceeded.

l (2) Results of the primary coolant analysis immediately before and after the limit was exceeded and the analyses performed during the time the limit was exceeded. For each result indicate the date and time of the sampling and the radiciodine concentrations.

l (3) Flow history of the Purification and Letdown system for the 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> prior to the first sample which indicated the DEI-131 l limit was exceeded.

1 I (4) Graph of the Iodine-131 concentration end one other radioiodine isotope concentration in pCi/ml as a function of time for the duration that the primary coolant iodine activity was above a j steady-state level.

(5) The time duration that the primary coolant activity exceeded the j DEI-131 limit, i l

The annual report shall be titled " Annual Primary Coolant Activity Report." The report shall be due March 1 of each year beginning in 1990, and shall cover events of the preceding calendar year.

Rancho Seco currently has a primary _ coolant specific activity Technical Specification limit of 43/E, This E limit is 43 percent of the NUREG-0103 j E limit. E is defined in the Rancho Seco Technical Specifications and j excludes iodines, consistent with NUREG-0103. To maintain consistency with j the relationship between the Rancho Seco Technical Specifications and l NUREG-0103, the administrative primary coolant iodine concentration limit j curve is ratioed by a factor of 0.43 to the NUREG-0103 iodine limit curve.

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George Knighton AGM/NTS89-016 The 1.0 pCi/mi DEI-131 primary coolant iodine concentration limit is adopted from NUREG-0103. This iodine concentration limit is more conservative than the existing 0.8 pCi/ml Iodine-131 limit committed to in the District's response to Generic Letter 85-02. U.S.A.E.C. publication TID-14844, dated March 23, 1963, presents data which indicates Iodine-131 contributes approximately 70 percent to the total DEI-131 concentration in primary coolant. Thus, a 1.0 pCi/ml DEI-131 limit (equivalent to approximately a 0.7 pCi/ml Iodine-131 limit) is more conservative than the current 0.8 pCi/ml Iodine-131 limit.

Members of your staff with questions requiring additional information or clarification may contact Mr. Richard Mannheimer at (209) 333-2935, extension 4916.

Sincerely, l

Bob G. Croley Assistant Gerieral Manager Nuclear Technical Services Attachment cc w/atch: J. B. Martin, NRC, Halnut Creek A. D'Angelo, NRC, Rancho Seco C. Hillis, NRC, Washington DC

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AGM/NTS89-016 l MANUAL: RANCHO SECO PROCEDURE MANUAL NUMBER: RSAP-0222 REVISION: 1 TITLE: RANCHO SECO CHEMISTRY CONTROL COMMITMENT PAGE 25 0F 31 QOSE EOUIVALENT I-131 ut x ter a i

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% inermal F:wer DOSE EQUIVALENT I-131 Primary Coolant Specific Activity Limit Versus Percent of RATED THERMAL POWER with the Primary Coolant Specific Activity

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