ML20207N562
| ML20207N562 | |
| Person / Time | |
|---|---|
| Site: | Fermi  |
| Issue date: | 01/12/1987 |
| From: | Agosti F DETROIT EDISON CO. |
| To: | NRC OFFICE OF ADMINISTRATION (ADM) |
| References | |
| VP-NO-87-0007, VP-NO-87-7, NUDOCS 8701140291 | |
| Download: ML20207N562 (3) | |
Text
r (I$er'$1nY n e.., ope,.uon.
Detroit ru Edison E55F" w.L.
January 12, 1987 VP-NO.-87-0007 U. S. Nuclear Regulatory Cormnission Attn: Document Control Desk Washington, D. C. 20555 Reterence: 1) Fermi 2 NRC Docket No. 50-341 NRC License No. NPF-43
Subject:
Condensate Storace Tank On January 8, 1987, a conterence call was held betwecn Messrs. J. Stefano and W. Meinke ot the NIC and Messrr.
T. Randazzo, R. Andersen and S. Frost of Detroit Edison. The purpose of that call was to discuss the events surrounding the Fermi 2 Condensate Storage Tank (CST) spill of November 17, 1986. During this discussion, Detroit Edison connitted to submit the following information concerning any corrective actions that have been taken and a schedule for those actions in progress. In addition, LER 86-45 has been generated and will be submitted by January 12, 1987.
At 1930 hours0.0223 days <br />0.536 hours <br />0.00319 weeks <br />7.34365e-4 months <br /> on November 17, 1986, with the reactor in cold shutdown, a weld failed on the HPCI/RCIC test line penetration at the bottom of the CSr. The weld failure was due to overpressurization of the test line, which caused deformation of an expansion bellows and related movement of the test line against the tank bottom failing the weld. The failed weld resulted in leakage ot approximately 275,000 gallons of slightly contaminated water trom the C9r. The CST spill water soaked into the ground in the diked area surrounding the CST while some of the water flowed into underground cable ducts. Approxinately 160,000 gallons ot dilute contaminated water was recovered from the cable ducts and processed thru to the Radwaste facility.
The cause of the event has been attributed to insutticient overpressure protection on the HPCI/BCIC test line, in combination with a sequencing ot valves in a manner which resulted in a high pressure water source being valved into an isolated low pressure rated systen.
y
- d Spill water samples indicated radioactivity concentrations ot approximately 2% (0.02) of the Maxinom 9
DOhK hhh$$$q 0
USNBC January 12, 1987 VP-NO-87-0007 Page 2 Permissible Concentration (MPC) values specified in 10CFR20, Appendix B, Table II, Column 2, for radioactivity in effluents to unrestricted areas. The detectable radioactivity consisted primarily of tritium (H-3) with trace quantities of Cobalt-58. In addition, samples taken in the CST diked area following the spill indicated trace levels of radioactivity in the soil.
Using the methods of the Fermi 2 Offsite Dose Calculation Manual (ODCM), a maxinom potential dose to a member of the public through fish and water consunption was calculated as 0.00002 millirem (2/100,000ths of a millirem). H is is well below the value of 3 millirems per year which is given in the Fermi 2 Technical Specifications as the limit for total body radiation exposure fr a liquid radioactive effluents to a member of the public.
Corrective actions which have been taken include the following:
1.
Electrical interlocks have been installed to preclude simultaneously closing the CST and CRr valves on the test line.
2.
Three (3) pressure relief valves have been installed which are capable of relieving design pressure flows to the CErr/CRP diked area to prevent overpressurization and potential
- releases, i
i 3.
We CRD minimum flow line involved in the event l
has been relocated to prevent overpressurization of the line section.
t 4.
Certain valves and affected line sections have been replaced with higher pressure-rated couponents to prevent pipe overprc-asurization.
l 5.
Overflow gutters have been installed on the CSI and the CRP to prevent any future overflow from splashing outsi6e the diked area.
6.
An alarm has been installed to warn control rom personnel that CSr or CRP overflow con 6u !ons exist.
7.
The Csr/CRP diked area has been sealed with a liner to contain any future spill water for recovery.
l
USNRC January 12, 1987 VP-N>-87-0007 Page 3 8.
An engineering review of other system designs for potential overpressurization events has been coupleted;. corrective action to address identified concerns have been made.
9.
Procedures associated with identified concerns regarding valve manipulations have been modified and designated as required reading by Operations grsonnel.
- 10. Responsible personnel involved in the event he.ve been disciplined.
Additional actions which are in progress include the following:
1.
A review of plant design and procedures for potential radiological releam pathways is being conducted; identified concerns or inprovements are being addressed to preclude unmonitored or uncontrolled liquid releases. Expected Coupletion Date (D): March 31, 1987 2.
Sampling and analysis of the CSP diked area soil is being conducted to couplete a final radiological assessment and respond to related regulatory actions; as is reasonable, arri weather conditions permitting.
2: March 31, 1987 If you have any questions, please contact Mr. Steven Frost at (313) 586-4210.
Sincerely, A
h 4 -4 d e-cc: Mr. J. J. Stefano Mr. W. G. Rogers USNRC Region III l
.