05000409/LER-1982-016, Forwards LER 82-016/03L-0.Detailed Event Analysis Encl

Forwards LER 82-016/03L-0.Detailed Event Analysis Encl

ML20058J399
Person / Time
Site:	La Crosse File:Dairyland Power Cooperative icon.png
Issue date:	07/29/1982
From:	Linder F DAIRYLAND POWER COOPERATIVE
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
Shared Package
ML20058J403	List: 05000409/LER-1982-016, Forwards LER 82-016/03L-0.Detailed Event Analysis Encl 05000409/LER-1982-016-03, /03L-0:on 820702,during Refueling Outage 1,200 Gallons of Water Leaked from Condensate Demineralizer Sys. Caused by Resin Addition Not Closing When Turned to Close. Valve Control Relay Replaced
References
LAC-8457, NUDOCS 8208090249
Download: ML20058J399 (4)

LER-1982-016, Forwards LER 82-016/03L-0.Detailed Event Analysis Encl

Event date:
Report date:
4091982016R00 - NRC Website

text

.. _ _..

DlDA/RYLAND h

[k COOPERAT/VE

• PO BOX 817

• 2615 EAST AV SOUTH

• LA CROSSE. WISCONSIN 54601 (608) 788 4 000 July 29,1982 In reply, please refer to LAC-8457 DOCKET N0. 50-409 He. James G. Keppler, Regional Administrator U. S. Nuclear Regulatory Commission Directorate of Regulatory Operations Region III 799 Roosevelt Road Glen Ellyn, Illinois 60137

SUBJECT:

DAIRYLAND POWER COOPERATIVE LA CROSSE B0ILING WATER REACTOR (LACBWR)

PROVISIONAL OPERATING LICENSE N0. DPR-45 REPORTABLE OCCURRENCE NO. 82-16

REFERENCES:

(1)

LACBWR Technical Specifications, Section 6.9.1.9.b.

(2) 10 CFR 20.405.a.5 (3) LACBWR Technical Specifications, Section 6.12.2

Dear Mr. Keppler:

In accordance with References 1 and 2, this is to inform you of abnormal degradation of a system designed to contain radioactive material, which resulted in release of concentrations of radioactive material to an unrestricted area in excess of ten times the Maximum Permissible Concentration set forth in 10 CFR 20.

During startup of the condensate system on July 2,1982, during a refueling outage, approximately 1200 gallons of water were released to the Turbine Building floor over a five minute period. Approximately 1125 gallons were recovered by the waste water tanks, about 20 gallons entered the ground in the radiologically controlled area outside the west turbine hall door and the turbine hall truck bay door, and an estimated 30 gallons were recovered from the oil separator overflow sump, with the remaining 25 gallons discharged to an unrestricted area.

The cause of the spill was as follows.

New resins had been added to the Number 1 Condensate Demineralizer Service Tank on July 1.

Following the resin addition, the control switch for the Resin Inlet Valve Tank No. 1 (63-25-004) had been turned to "close", as per procedure, but the valve did not actually close. The control switch is located on a local panel outside the Condensate Demineralizer Room shield walls.

The entrance to the room is barricaded by a locked gate per Reference 3.

Since the Resin Inlet Valve Tank No. I was open, when the condensate system was started on July 2, the resin fill line was exposed to the operating system pressure of approximately 300 psig.

(See attached drawing).

The gaskets on B208090249 820729 2

WP-6.5 PDR ADOCK 05000409

'M S

PDR JfAh

Mr. James G. Keppler, Regional Administrator July 29, 1982 U. S. Nuclear Regulatory Commission LAC-8457 the bulls eye sightglass in the resin fill line could not hold the pressure and water started spilling onto the floor.

The Shif t Supervisor heard an unusual noise and investigated.

He had the condenste system shutdown and the service tank isolated. The leak was stopped in approximately 5 minutes.

Since the drain system from the Condensate Demineralizer room is blocked with grout (Refer to R0 No. 80-12), water flowed onto the grade floor of the Turbine Building. Approximately 20 gallons of water passed under the wes turbine hall door and the truck bay door combined.

Some water entered the clean (non-contaminated) drain system, and the west turbine sump, and from there passed into the oil separator overflow sump, which is the receiving sunp for several clean drain systems.

Investigation and testing have demonstrated that some contaminated water flowed into the Mississippi River, through a line which had been blocked with a concrete plug, which was no longer in evidence.

From the discharge into the river, the majority of water was then claimed by the suction of the Genoa Unit No. 3 condenser circulating water, where it mixed with 130,000 gpm of riverwater, prior to being finally discharged to the river. A slight amount of contaminated water probably passed through erosion holes in the overflow sump into the ground. Approximately 30 gallons of contaminated water was discovered in the overflow sump. This water was pumped into the plant waste water system. A total of about 25 gallons of contaminated water was estimated to have passed into the environment.

The concentration of radionuclides found in the west turbine building sump was as follows:

Radionculide uCi/ml

% Composition Co-60 2.3 x 10 4 50%

Mn-54 8.2 x 10 5 18%

Co-58 4.8 x 10 5 11%

Fe-59 2.3 x 10 5 5%

Zn-65 8.6 x 10 6 2%

Ce-144 2.1 x 10 5 5%

Nb-95 1.9 x 10 5 4%

Zr-95 1.1 x 10 5 2%

Ru-103 6.8 x 10 6 1%

Ce-141 5.0 x 10 6 1%

Rh-105 2.5 x 10 6 1%

Cs-137 5.3 x 10 7 0.2%

TOTAL......

4.57 x 10 4 WP-6.5 - _. - _.... - _.

F Mr. James G. Keppler, Regional Administrator July 29, 1982 U. S. Nuclear Regulatory Commission LAC-8457 The concentration of radionuclides found in the oil separator overflow sump was as follows:

Radionculide uCi/ml

% Composition Co-60 2.4 x 10 "

49%

Mn-54 8.4 x 10 5 17%

Co-58 5.1 x 10 5 10%

Fe-59 2.4 x 10 5 5%

Zn-65 1.0 x 10 3 2%

Ce-144 2.1 x 10 5 4g Nb-95 1.9 x 10 5 4%

Zr-95 1.3 x 10 5 3%

Ru-103 6.9 x 10 6 1%

Ce-141 4.7 x 10 6 1%

Cr-51 6.3 x 10 6 1%

Cs-137 8.0 x 10 7 0%

TOTAL......

4.87 x 10 4 Since the activity in the overflow sump was approximately the same as in the west turbine sump, it did not appear to be diluted by water possibly standing in the overflow sump prior to the spill. Therefore, it was assumed that the concentration of the water discharged to the river was 4.87 x 10 4 pC1/ml, of the composition found in the overflow sump. Based on the Maximum Permissible Concentrations in water of the individual radionuclides, the discharge to the river was determined to be 12.6 MPCw.

If the dilution achieved by the contaminated water passing through the Genoa Unit 3 circulating water system prior to being permanently discharged into the river is taken into account, the discharged water concentration was 0.05%

MPCw.

The total number of curies discharged to the river was approximately 5 x 10 5 C1.

Several actions have been taken since the incident to prevent reoccurrence and others are underway.

The Resin Inlet Valve, which is a 2 inch, motor-operated valve manufactured by Ramcon Corporation was examined. An open contact was discovered in the Potter Rumfield control relay, which opens and closed the valve. The relay was replaced. A poor contact was found on the relay which controls the Potter Rumfield relay, which caused a wire to burn out, resulting WP-6.5 r

Mr. James G. Keppler, Regional Administrator July 29, 1982 U. S. Nuclear Regulatory Commission LAC-8457 in the open contact.

This relay was overhauled and reinstalled. The valve mechanically moved without problem, though the limit switch may have been slightly sticky.

The limit switch was removed and exercised, after which it moved properly.

The valve was tested several times, operating satisfactorily.

Other similar valves in the system were also checked.

No additional malfunctions were noted.

The drop gate between the west turbine sump and the oil separator overflow sump was closed to prevent any future potentially contaminated water from reaching the overflow sump.

A 1/4 inch thick carbon steel plate disk was installed in the end of the 10 inch clay pipe bell located in the overflow sump. The plate was dammed in place with concrete, resulting in the establishment of a substantial plug in the 10 inch line to the river. An integrity test of the overflow sump demonstrated that the sump itself is not leaktight, so it will not be utilized as is. A Facility Change has been initiated to modify the existing floor drain system to remedy the problems associated with it.

The contaminated soil outside the turbine building was removed and placed in barrels. All areas were decontaminated.

The gaskets on the bullseye sightglass were replaced.

Procedures were followed throughout the event.

Operators were in attendance and prompt remedial actions were taken by plant personnel.

A Licensee Report (Reference: Appendix A, Regulatory Guide 1.16, Revision 4) is enclosed.

If you have any questions, please contact us.

Very truly yours, DAIRYLAND POW COOPERATIVE g

br' Frank Linder, General Manager l

FL:LSG:eme Enclosures cc: Document Control Desk l

U. S. Nuclear Regulatory Commission Washington, D. C.

20555 INP0 Institute of Nuclear Power Operations 1820 Water Place l

Atlanta, GA 30339 NRC Resident Inspector WP-6.5