ML11297A015
| ML11297A015 | |
| Person / Time | |
|---|---|
| Site: | La Crosse File:Dairyland Power Cooperative icon.png |
| Issue date: | 10/11/2011 |
| From: | Berg W Dairyland Power Cooperative |
| To: | Document Control Desk, NRC/FSME |
| References | |
| LAC-14191 | |
| Download: ML11297A015 (2) | |
Text
WILLIAM L. BERG President and CEO DAiRYIAND POWER COOP E RAT IV E
October 11, 2011 In reply, please refer to LAC-14191 DOCKET NO. 50-409 Document Control Desk U. S. Nuclear Regulatory Commission Washington, DC 205553-001
Dear Sir or Madam:
SUBJECT:
Dairyland Power Cooperative (DPC)
La Crosse Boiling Water Reactor (LACBWR)
Possession-Only License No. DPR45 Off-site Dose Calculation Manual Commitment
REFERENCE:
(1) LACBWR Offsite Dose Calculation Manual, Rev. 11, December 2008 (Reviewed with no changes December 2010)
On September 9, 2011, DPC was reviewing the requirements of the Offsite Dose Calculation Manual (ODCM) for monitoring of reactor building exhaust air when it became evident the plant's ventilation configuration was not in full compliance with the ODCM. Section 3.3.1 of the ODCM regarding Gaseous Effluents, specifically Reactor Building Ventilation, contains a requirement for filtering of all reactor building gaseous effluents when the reactor building ventilation dampers are open. This section states that filtration of the exhaust implements the requirements of 10 CFR 50.36a, General Design Criterion 60 of Appendix A to 10CFR5O, and the design objectives given in section ILD of Appendix I to 10 CFR 50.
The normal configuration of the ventilation system for the last several years has been such that the majority of the reactor building gaseous effluent was discharged through the airlock to the tunnel then to the stack to ensure the effluents were monitored before release. The inlet dampers were maintained shut and the exhaust dampers left in the open position. A small portion of the effluent discharge from the reactor building was pulled through the installed HEPA filters using the stack blowers. This ventilation lineup was put into place after the installation of the reactor building bi-parting door to ensure air flow was maintained into the reactor building from outside sources thus preventing a potential unmonitored radioactive gaseous release.
DPC has taken immediate corrective action to prevent recurrence and comply with the ODCM requirement to filter reactor building exhaust air by operating the reactor building exhaust fan and verifying air is discharged through the exhaust filters. Additional actions may be developed based on the results of Corrective Action Report (CAR) 2011-137 initiated for this issue. During the corrective action process, a root cause analysis will be completed which will review the extent of condition. The root cause analysis was initiated immediately and is on-going due to the extensive amount of records to review. The A Touchstone Energy Cooperative 3200 East Ave. S.
- PO Box 817
- La Crosse, WI 54602-0817
- 608-787-1258
- 608-787-1469 fax
- www.dairynet.com
Document Control Desk LAC-14191 Page 2 October 11, 2011 history involved regarding the reactor building ventilation configuration dates back to 1995. Potential long term solutions identified thus far include developing an ODCM change to better reflect the status of the plant since permanent shutdown, re-training personnel on the 50.59 process and ODCM, and reviewing related 50.59 screenings and evaluations to address the extent of condition.
DPC has reviewed gaseous effluent data from 1990 to 2010 to determine if bypassing the filtration units has had a measureable effect on doses to the public. The release data indicate that the effect of operating without HEPA filtration is insignificant. The doses during the period from 1995 through 2010 (potential timeframe of bypassed filtration) are less than a few percent of the doses from 1990 to 1995 (with filtration). For purposes of estimating the maximum dose reduction that could be achieved by filtration, it is assumed that the filters are 99% efficient. With this assumption, the largest possible dose reduction would be 99% of the maximum dose during the period from 1995 through 2010, which is 1.58E-4 mRem.
This is an insignificant fraction of the dose limits of 10CFR 20 (100 mRem TEDE), 40 CFR 190 (15 mRem organ dose) or 10 CFR 50 Appendix 1 (15 mRem organ dose).
DPC has concluded a violation of the LACBWR License and Technical Specification has not occurred.
The ODCM requirement states if the reactor building exhaust is being discharged without filtration then a report needs to be submitted to the NRC within 30 days. This letter report is to satisfy the requirement for the 30 day report. Once the root cause analysis is completed and the corrective actions are approved, DPC will submit a follow-up summary of the findings and corrective actions. This analysis will be submitted no later than December 16, 2011.
If you have any questions, please contact LACBWR Plant Manager Mike Brasel at (608) 689-4220.
Sincerely, William L. Berg, Presiden~and CEO WLB:MAB:jkl cc:
John Hickman Project Manager U.S. Nuclear Regulatory Commission Mark Satorius Regional Administrator, Region III U.S. Nuclear Regulatory Commission Paul Schmidt Manager, Radiation Protection Section State of Wisconsin