ML19329A530
| ML19329A530 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 07/07/1977 |
| From: | Grimes B Office of Nuclear Reactor Regulation |
| To: | Goller K Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8001060045 | |
| Download: ML19329A530 (4) | |
Text
{{#Wiki_filter:v- /bvM4 r.c JUL 0 7 igyy } MEHoaANDUM FOR: Karl R. Coller, Assistant Director for Operating Reactors, DOR FROM: Brian K. Crimes, Chief, Environmental Evaluation Branch, DOR i I OCONEE RADIGACTIVE LIQUID EFFLUENTS - EXCEEDING REPORT
SUBJECT:
LEVEL OF ONE-HALF DESIGN OBJECTIVE IN A QUARTER I FLANT 51ME: Oconee Nuclear Station, Unit Nos.1, 2 and 3 ' ' ' ~' DOCKET NUMBERS: 50-269, 270, 287 l f RESPONSIBLE BRANCH: ORB-1 PROJECT MANAGER: D. Neighbors By letter to the NRC dated April 25, 1977, Duke Power Company reported l that the Oconee liquid radioactive releaea had exceeded one-half the i This release rate ex-- design objective releases in a calendar quarter. [ ceeded the 30-day reporting requirement of Spscification 3.9.1. As a i result of our review of these releases we have concluded that additional monitoring and administrative controls are required at the Oconee fa-1 ) cility to keep radioactive releases as low as reasonably achievable in accordance with Appendix I to 10 CFR Part 50. We request that you initiate appropriate technical specification changes. J Per the reporting requirement the licensee must: a) Make an investigation to identify the cause for such release j rates; b) Define and initiate a program of action to reduce such release rates to the design objective levels, and; i c) Describe these actions in a report within 30 days. The April 25, 1977 letter fulfilled the reporting requirement and refer-enced Attachment A to an April 20, 1977 letter from Duke Power (Mr. C. Born, Jr.) to the NRC (Mr. E. Volgenau) to identify the cause and the l corrective action takan. The April 25, 1977 letter also identified a 15, 1977 letter from D ske Poesr to NRC which gave initial noti-February fication that one-half the design objectives were exceeded in the first i quarter of 1977 and identified the incident causing the abnormally high Y
Contact:
J. S. Bland / EEB, DOR orric s > a e....e
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i 3 0-M07 377 K. Coller l releases (Reportable Occurrence Report RO-269/77-3, submitted to OI&g, i NRC, Ragion II by letter dated February 3,1977). I i The Reportable Occurrence Report described an inadvertent release of liquid radioactivity ('3.2 Ci of I-131) from Unit 1 to the Keowee River. The incident identified as causing this release was a main generator hydrogen cooler gasket leak to the turbine building sump with the sump aligned to discharge to the oil collection basin while steam generator The usual was being leak tested to repair a steam generator tube leak. procedure for identifying a leaking tube is to drain the steam generator to liquid radwaste system if the secondary water is contaminated. The A change was made in steam generator is then filled with clean water. these procedures allowing leak testing prior to drainage of the steam I I During the testing a leak developed in the hy-generator to radwaste. This leak resulted in an unmonitored and uncon-p drogen cooler gasket. i trolled discharge to the Keowee River which resulted in reimes exceed-ing the maximum instantaneous concentration limits of 10 CFR Part 20, i The total releases exceeded one-half Appendix B. Table II, Column 2. the design objectives in a calendar quarter. 20, 1977 letter fr&L Duka Power, describing the corrective The April i action to prevent reoccurrence, reiterated Oconee administrative pro- { cedurs requirements for plugging steam generator tube leaks and for con-I The licensee did not I trolling secondary side contamination and leakage. propose the installation of any radiation monitors to alert the operators i of a release nor a composite sampler which would provide a record of the magnittvle of a release if it did occur. His position was that administra-l 4 tive control alone was sufficient to monitor and control radioactive I liquids during periods of steam generator tube leakage. On May 7,1977 Oconee Unit i experienced a steam generator leak and re-? actor shutdown was commenced to find and repair the leak. Despite the i administrative procedural controls that the licensee implemented to \\' contain the radioactive liquids on the secondary side, radioactive liquid' from the affected steam generator entered the turbine building sump via a steam system bypass valve. The turbine building sump was aligned to again I to the oil collection pond and the Keowee River. The contamination was-L ever *.he re%. detected by taking periodic grab samples from the sump. lease continued for several house before it was detected and corretive, action taken. The quantity of radioactivity released was not significant, the release of approximatsly 0.015 curies;.however, lack of indication o4 k radioactive materials to the operators is a significant concern. i On June 1,1977 the NRC staff (L. Barrett and S. Bland, EE8; D. Neighbors, .s ORPH; and A. Kowalczuk, Region II) met with the licenses at the Ocones site their iethod of controlline radioactivity in the secondarv en Macuna a stbn following a steam generator leak. Th0 licensee described their 41. ..;.1.. via c.l..;;l ;- ml; t: ;;;t:i:,;;21 201 y in th; ::::d .u==.eny side. The tuibine buildinz drainese sys1.em, condensat a polisher ra sin e.i+ l l NRC l'oRM 31s (9-76) NRCM 0240 - W u.s.sovsanusur pamtme orreces sere-eaomas
je 3-0 7 g7 l' K. Coller disposal systes, vaste water co11setion basins, and oil collection basin were examined with respect to detecting, containing and controlling radio-active materials. It was noted that a radiation monitor had been installed to monitor the turbine building sump effluent on a trial basis. While the licensee has improved the control of secondary side liquid radio-activity, the proposed administrative procedures alone are not considered adequate because of the complexity of the secondary system and the fre-quency of steam generator leaks. The release of radioactivity in May is an example of this. Although the licenses has instituted administrative procedures, a release of radioactive material did occur in an uncontrolled manner. Although in this case the amount was not si nificant, it was E indicative of a lack of control over radioactivity which has the potential for release of a larger amount of radioactivity. We consider that adequate control can be established by a combination of administrative procedures and installed instrumentation. Consequently we recommend that the licensee be requested to submit Technical Specification changes for the Oconee Station to:
- 1) include the installed turbine building sump monitor with an alarm in the control room,
- 2) add a composite water sampler at th's outfall of the oil collec-tion basin with weekly gamma spectra analysis and quarterly Sr-89, Sr-90 analysis, and
- 3) add procedural requirements for two independent checks on valve alignment for discharges of radioactive. spent resin from the secondary water clean-up sys tem to the receiving tanks to prevent an inadvertent release of highly contaminated resins following steam generator leaks to the waste water collection basin.
These positions have been discussed with Duke Power and the licensee has indicated that the changes would be implemented if required by NRC. With the above changes to the Oconee Technical Specifications, proper control over secondary side radioactivity can be maintained and inadvertent i'* releases minimised. Brian K. Crimes Chief Environmental Evaluation Branch i Division of Operating Reactors cc: Ses page 4 ovveen y. 1 ownwaus > i cars > j NaC PotM SIS (976) NRCM O24s W u: e. eovannuswv ensurine orrecs, s eve -eae.ea4 i i _ _ __}}