05000409/LER-1981-006, Forwards LER 81-006/01T-0.Detailed Event Analysis Encl

Forwards LER 81-006/01T-0.Detailed Event Analysis Encl

ML20004D132
Person / Time
Site:	La Crosse File:Dairyland Power Cooperative icon.png
Issue date:	05/29/1981
From:	Linder F DAIRYLAND POWER COOPERATIVE
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
Shared Package
ML20004D133	List: 05000409/LER-1981-006, Forwards LER 81-006/01T-0.Detailed Event Analysis Encl 05000409/LER-1981-006-01, /01T-0:on 810518,during Installation of Attachment on Containment Pressure Sensing Line,High Containment Bldg Pressure Starting Signal to HPCS Pump 1B,auxiliary Cooling Sys Pump & AC Valve Was Isolated.Procedures Not Followe
References
LAC-7571, NUDOCS 8106080445
Download: ML20004D132 (5)

LER-1981-006, Forwards LER 81-006/01T-0.Detailed Event Analysis Encl

Event date:
Report date:
4091981006R00 - NRC Website

text

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D DA/RYLAND h

[k COOPERAT/VE eo soxsi7 esis EAST AV SOUTH LA CROSSE. WISCONSIN M601 y

(60a17es4000 May 29, 1981 In reply, please o

o refer to LAC-7571 DOCKET.NO. 50-409

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Mr. James G. Keppler, Director U. S. Nuclear Regulatory Co:tmission o>

Directorate of Regulatory Operations

,G Region III 799 Roosevelt Road

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SUBJECT:

DAIRYLAND POWER COOPERATIVE L's JUN 0519816 32 LA CROSSE ECILING WATER REACTOR (LACBWR)

", ' ' T M '***

PROVISIONAL OPERATING LICENSE NO. DPR-45 C'

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p, REPORTABLE CCCURRENCE NO. 81-06 4l

(*

References:

(1)

DPC Letter, LAC-7555, Linder to Keppler, dated May 19, 1981.

(2; LACBWR Technical Specifications, Section G.8.1.

(3)

LACBWR Technical Specifications, Section 6.5.1.6.d.

(4) u.unr.wechnical Specifications, Section 4.2.2.18.

(5)

LAC 3WR Technical Specifications, Section 4.2.2.15.

(6)

LACBWR Technical Specifications, Section 4.2.1.1.

(7)

LACBWR Technical Specifications,, Section 4.0.1.

(8)

LACBWR Technical Specifications, Section 5.2.1.1. (b).

Dear Mr. Keppler:

This letter constitutes the written follow-up to the event reported to you in Reference 1.

The subject occurrence involved the discovery on May 18, 1981 of an attachment which had been added to the Contain-ment Building pressure sensing line leading to Pressure Switch 37-35-702 which activates IB High Pressure Core Spray Pump (HPCS) and 1B High Pressure Service Water (HPSW)/ Alternate Core Spray (ACS) pump and sends one of two required opening signals to the AC Alternate Core Spray Valve on high Containment Building pressure of 5 psig.

The in-I stallation had been made without an approved Maintenance Request or Facility Change.

. 88106 080 49$

Mr. James G. Keppler, Director LAC-7571 U. S. Nuclear Regulatory Commission May 29, 1981 This is contrary to DPC procedures, Reference 2, which requires that written procedures be implemented and Reference 3, shi~ch requires that the Operations Review Committee review all proposed changes or modifications to unit systems or equipment that affect nuclear safety.

The attachment consisted of an additional pressure switch, and isolation and drain valve, and 1/4 in. copper tubing (see attached sketch).

The attachment had been assembled and leak tested at 60 psig without leakage prior to being installed.

Reference 4 requires that the low pressure coolant injection system (ACS) shall be available for automatic operation except at times when the reactor is shut down and the system depressurized to approximately atmospheric pressure.

Reference 5 allows one core spray pump to be removed from service for maintenance provided that all control rods are fully inserted, the reacter pressure is less than 85 psig, the " Control Power" key switch is in the "0FF" position, and the low pressure core spray subsystem is operable.

During the installation on April 1, 1981, while the reactor was at 85% Rated Thermal Pcwer, the valve between the conrainment wall and Pressure Switch 37-35-702 was closed for less than one minute, there-by deactivating the pressure switch.

Therefore, the installation process reduced the degree of redundancy of actuating signals for the 1B HPCS Pump, 1B HPSW/ACS Pump and AC ACS valve, but would not have prevented system actuation if required.

Since a leakage test had not been performed immediately following installation, verification that Containment Integrity, as rcquired by References 6 and 7, was not reduced, was not achieved.

In order to accomplish a leakage test of the installation, it was necessary

' to prevent r " anted operation of the IB EPCS pump.

This temporary deactivatior.

guired advanced authorization frcm the NRC.

The de-activation wa. accomplished by placing the 1B HPCS pump in " PULLOUT",

thereby preventing pump start with consequential injection of cold water into the reactor.

A leakage test was performed on May 19, 1981.

The previously untested connections did not leak, however, an extremely small amount of leak-age was detected by the soap bubble method on the new isolation valve leading to the new pressure switch.

The amount of leakage observed, when comparing the size and rate of bubbles, appeared considerably less than'what has previously been observed during electrical pene-tration tests with acceptable leakage rates.

Therefore, the test was considered acceptable. i

Mr. James G. Keppler, Director LAC-7571 U. S. Nuclear Regulatory Commission May 29, 1981 Since the maximum leakage allowable through an electrical penetration ir. 0.375 SCFH, the leakage through the attachment can be assumed -

to be less than 0.375 SCFH'."

If this amount of leakage is added to the as-left Containment Building leakage after the Type A test in December, the leakage rate would be 29.95 SCFH + 0.375 SCFH =

30.33 SCFH, or 0.06% per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, still well within the Technical Specification limit (Reference 8) of 0.1% per day, on which the accident analyses have been based.

Therefore, the actual safety consequences of the pressure switch installation were minimal.

After the satisfactory leakage test on May 19, 1981, the installation was removed and the system returned to its initial configuration.

Another leakage test was then conducted with zero leakage observed.

This event has been discussed with the responsible departments and individuals involved.

The importance of following the procedural requirements for proper review of proposed modifications has been atrossed.

This action should prevent reoccurrence of similar events.

A Licensee Event Report (Reference:

Regulatory Guide 1.16, Revision 4) is enclosed.

Should you have any questions regarding this submittal, please contact us.

Very truly yours, DAIRYLAI!D PCWER CCOPEPATIVE Frank Linder, General Manager FL:LSG:af Enclosures

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. Mr. James G. Keppler, Director -

LAC-7571 U.. S. Nuclear Regulatory Comissicn May 29, 1981 a

cc:

Director, Office of Inspection and Enforcement - (3 0 )

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

20555 Director, Office of Management Information and (3)

Program Control U. S. Nuclear Regulatory Comission Washington, D. C.

.20555 NRC Resident Inspectors 9

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