ML20237B171
| ML20237B171 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 11/25/1987 |
| From: | Shawn Smith TENNESSEE VALLEY AUTHORITY |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| 87-17, NUDOCS 8712160070 | |
| Download: ML20237B171 (4) | |
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TENNESSEE VALLEY AUTHORITY Sequoyah Nuclear Plant Post Office Box 2000 l
Soddy-Daisy, Tennessee 37379 November 25, 1987 U. S Nuclear Regulatory Commission Document Control Dest Washington, DC 20555 Gentlemen:
TENNESSEE VALLEY AUTHORITY - SEQUOYAH NUCLEAR PLANT UNITS 1 AND 2 - DOCKET NOS. 50-327 AND 50-328 - FACILITY OPERATING LICENSE DPR-77 AND DPR SPECIAL REPORT 87-17 The enclosed special report provides details concerning liquid releases from condensate demineralized waste system directly to the cooling tower blowdown line when effluents exceeded the 31-day total body projected dose limit.
This event is reported in accordance with action statement (a) of Limiting Conditions for Operation 3.11.1.3.
Very truly yours, TENNESSEE VALLEY AUTHORITY g[c S.
m Plant Manager Enclosure cc (Enclosure):
J. Nelson Grace, Regional Administrator U. S. Nuclear Regulatory Commission j
Suite 2900 101 Marietta Street, NW Atlanta, Georgia 30323 Records Center Institute of Nuclear Power Operations Suite 1500 1100 Circle 75 Parkway Atlanta, Georgia 30339 NRC Inspector, Sequoyah Nuclear Plant V
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SEQUOYAH NUCLEAR PLANT UNITS 1 AND 2 SPECIAL REPORT 87-17 DESCRIPTION OF EVENT On November 5, 1987, with units 1 and 2 in mode 5 (0 percent power, 3 psig, 120 degrees and 0 percent power, 114 psig, 100 degrees F, respectively), it was discovered (via a review of previously performed 11guld effluent dose calculations) that on two occasions, the Technical Specification (TS) Limiting j
Condition for Operation (LCO) 3.11.1.3 total body projected dose limit was exceeded, and releases were made without processing through the radwaste treatment system. TS LCO 3.11.1.3 requires the liquid rsdwaste treatment system to be used to reduce the radioactive materials in liquid wastes before their discharge when'the projected doses due to the liquid effluent to unrestricted areas would exceed 0.06 mrem per unit to the total body or 0.2 mrem per unit to any organ in a 31-day period.
In June 1985, radioactive liquid releases were made with a projected dose of 0.14 mrem to the total body, and in July 1985, radioactive liquid releases were made with a projected dose of 0.17.1mem to the total body. These releases were made from the condensate demineralized waste systems directly to the cooling tower blowdown line.
In August 1984, a new high crud filter was installed in line between the high crud tanks, which are part of the condensate demineralized waste system, and the cooling water blowdown line. This was a modification performed to provide a higher flow capacity discharge path necessary to support unit 1 and unit 2 releases. The postmodification testing has not been completed to date, and therefore, the filter has not been placed in operation. The filter is provided to reduce the suspended solids in a release. The releases made to the cooling tower blowdown line have been made through a filter bypass line.
This is contrary to Final Safety Analysis Report (FSAR) section 11.2 when releasing the high crud tank when the contents are radioactive.
The condensate demineralized wastes are generated and collected during condensate demineralized regeneration process. This waste was radioactive due to a steam generator tube leak during the time the regenerated condensate l
demineralized bed was in service. The cooling tower blowdown line provides a l
release path for these wastes. The cooling tower blowdown line discharges to
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the diffuser pond which is released to the Tennessee River.
j A review of the documentation for actual releases made were wlthin the concentration limits of TS LCO 3.11.1.1 and Appendix B, Table 2, column 2, of 10 CFR 20.
CAUSE OF EVENT The procedure used during the subject releases in 1985 for dose calculations for liquid effluents (SI-422.1, Revision 0, " Monthly Appendix I Dose I
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Calculations Liquid Effluents") incorrectly stated the projected total body dose limit as 0.5 mrem and the maximum organ projected dose limit as 1.66 mrem.
Since the limits stated in SI-422.1, Revision 0, were not violated, a notification was not made to the lead Chemical engineer to ensure the liquid radwaste treatment system would be used during releases.
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The high crud filter was not placed in service because preoperational testing has not been completed, and thus it has not been turned over for operations.
SI-400.1 did not require the high crud filter to be in service when releasing to the cooling tower blowdown line, and thus a filter bypass line has been used when performing releases.
The above stated contributing problems are symptoms indicative of a weak program in the past for ensuring complete and accurate commitments / requirements are captured in implementing documents.
ANALYSIS OF EVENT This event is being reported in accordance with the requirements of. action statement (a) of TS LCO 3.11.1.3.
Recent samples were taken from the diffuser pond at eight different locations. These samples were analyzed for resin and activity. No resin was found in any of the diffuser pond samples. Trace amounts of activity were found in some samples. No diffuser pond samples exceeded 0.51 pC1/g wet for any one radioisotope.
Samples were also taken from yard pond and the low volume waste treatment pond, which are not directly released to the Tennessee River, but do receive condensate demineralized wastes.
Resin was found in the yard pond and low volume waste treatment pond. The highest activity found was 4.74 pC1/g wet from Cs-137 In the. low volume waste treatment pond.
It was postulated that this activity was deposited on the shoreline diffuser pond with a man standing near it for 365 days.
It was calculated that the man would receive approximately 1 mrem to the whole body under this scenarlo.
This analysis resulted in the conclusion that this event had no significant environmental impact.
CORRECTIVE ACTION Releases from the high crud tanks were immediately suspended until procedures were changed. The 11guld waste effluent batch release procedure (SI-400.1) has been revised to require the use of the high crud filter when releasing the high crud tanks to the cooling tower blowdown line.
The current revision (revision 3) of SI-422.1 contains the correct limits for total body and maximum organ 31-day projected doses.
It will be revised to require the radwaste system to be used whenever the projected dose exceeds the limits of TS LCO 3.11.1.3 before unit 2 enters mode 4.
A filter system will be made available for high crud tank releases before unit 2 entry into operational mode 4.
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An SI review program has been implemented to review surveillance instructions to ensure they are technically adequate and in compliance with TS.
The program review for technical adequacy and compliance with TS of procedures has i
been completed for unit 2.
sis are also subject to periodic reviews, and all SI revisions which implement a TS surveillance requirement will be review ^d to ensure their compliance.
The FSAR section 11.2 will be updated in the April 1988 revision to clarify the purpose of the high curd filter and when it is required to be used.
j An investigatica is continuing concerning these matters.
An update to tht?
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Investightlon will be reported by February 15, 1988.
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