05000295/LER-1997-012-02, :on 970423,determined That Test Criteria for H Recombiner Was Inappropriate.Caused by Low Std for for Documentation of Changes to Vendor Recommendations. Will Review Results of 1995 TS Compliance Self Assessment

:on 970423,determined That Test Criteria for H Recombiner Was Inappropriate.Caused by Low Std for for Documentation of Changes to Vendor Recommendations. Will Review Results of 1995 TS Compliance Self Assessment

ML20141K954
Person / Time
Site:	Zion File:ZionSolutions icon.png
Issue date:	05/23/1997
From:	Brennan N COMMONWEALTH EDISON CO.
To:
Shared Package
ML20141K952	List: 05000295/LER-1997-012, Forwards LER 97-012-00,which Documents 970423 Event That Occurred at Zion Generating Station.Commitments Made by Util,Listed 05000295/LER-1997-012-02, :on 970423,determined That Test Criteria for H Recombiner Was Inappropriate.Caused by Low Std for for Documentation of Changes to Vendor Recommendations. Will Review Results of 1995 TS Compliance Self Assessment
References
LER-97-012-02, LER-97-12-2, NUDOCS 9706020157
Download: ML20141K954 (5)

LER-1997-012, on 970423,determined That Test Criteria for H Recombiner Was Inappropriate.Caused by Low Std for for Documentation of Changes to Vendor Recommendations. Will Review Results of 1995 TS Compliance Self Assessment

Event date:
Report date:
Reporting criterion:	10 CFR 50.73(a)(2)(iv), System Actuation 10 CFR 50.73(a)(2)(v), Loss of Safety Function 10 CFR 50.73(a)(2) 10 CFR 50.73(a)(2)(1) 10 CFR 50.73(a)(2)(viii)(A) 10 CFR 50.73(a)(2)(viii)(B) 10 CFR 50.73(a)(2)(iii) 10 CFR 50.73(a)(2)(x)
2951997012R02 - NRC Website

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FACILITY NAME 30CKET NUMBER PAGE 0l5l0l0l0l2l9l5 1 l0Fl 0 l 5 j

ZION NUCLEAR POWER STATION TITLE INAPPROPRIATE TEST CRITERIA FOR HYOR0 GEN RECOMBINER BECAUSE OF INTERPRETATION OF TECH SPECS WITH MINIMAL IMPACT ON PLANT.

EVENT DATE LER NUMBER REPORT DATE OTHER FACILITIES INVOLVED MONTH DAY YEAR YEAR SEO.

REV.

MONTH DAY YEAR FACILITY NAMES DOCKET NUMBER (S)

ZION UNIT 7 0 l 5 l 0 l 0 l 0 l 3 l 0 l4 nl4 213 1

ol7 o

7 c1112 ole ois 213 ol7 I I I I I I I THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR $: (CHECK ONE OR MORE OF THE FOLLOWING) 6 20.402(b) 20.405(e) 50.73(a)(2)(iv) 73.71(b)

POWER 20.405(a)(1)(i) 50.36(c)(1) 50.73(a)(2)(v) 73.71(c) 0l0l0 LEVEL 20.405(a)(1)(ti) 50.36(c)(2) 50.73(a)(2)(vti)

OTHER (Specify in 20.405(a)(1)(fii)

X 50.73(a)(2)(1) 50.73(a)(2)(viii)(A)

Abstract below 20.405(a)(1)(iv) 50.73(a)(2)(ti) 50.73(a)(2)(viii)(B) l 36 20.405(a)(1)(v) 50.73(a)(2)(iii) 50.73(a)(2)(x)

LICENSEE CONTACT FOR THIS LER NAME TFtFPHONr NUMRrR Neil Brennan, Root Cause Ext. 2380 e1417 714181-12l ale 14 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT

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^

CAUSE

SYSTEM COMPONENT MANUFACTURER

CAUSE

SYSTEM COMPONENT MANUFACTURER Y

TO NPROS TO NPRDS I

I l l I I I I

I I I I II I

I I I I I I I

I I I I I I

)

SUPPLEMENTAL REPORT EXPECTED EXPECTED MONTH DAY YEAR SUBMISSION

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YES. (If yes. complete EXPECTED SUBMISSION DATE)

M NO DATE l

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ABSTRACT (Limit to 1400 spaces. i.e.

approximately fifteen single-space typewritten lines).

Technical specification #4.8.8. A requires readiness testing of the hydrogen recombiner in accordance with the manuf acturer's recommended tests. The plant testing procedures did not include the manufacturer's acceptance criteria for testing. Because the station tests contained acceptance criteria which were less restrictive. the specification requirements were not met. However, the testing performed j

was sufficient to confirm that the hydrogen recombiner would function as required to mitigate the effects of an accident. Though the specific root cause of the ever.t could not be determined. the apparent cause of the event was a low standard for documentation of changes to vendor information and for explicit Technical Specification compliance at Zion Station which assumed the Technical Specifications could be interpreted rather than followed explicitly. There was minimal safety significance to this event.

Corrective actions include: 1) changing the high level and low level test criteria to conform to the manufacturer's recommendations.

2) updating of the on site vendor manual to reflect new vendor recommendations. 3) the results of the 1995 Technical Specification compliance self assessment will be reviewed to ensure that other findings have been appropriately addressed.

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9706020157 970523 PDR ADOCK 05000295 S

PDR g:\\zler\\97012.ler(l)

LICENSEE EVENT REPORT (LER) TEXT CONTINUATION FACILITY NAME DOCKET NUMBER LER NUMBER PAGE YEAR SEO.

REV.

ZION NUCLEAR POWER STATION 0l5l0l0l0l2l9l5 9l7 0l1l2 0l0 0l2 0l5

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0F TEXT Energy Industry Identification System (EIIS) codes are identified in the text as [XX]

A.

PLANT CONDITIONS PRIOR TO EVENT Unit 1 MODE 6 - Refueling Rx Power 0%

RCS [AB] 74' F Atmospheric Pressure Unit 2 MODE 5 - CSD Rx Power 0%

RCS 83 F Atmospheric Pressure B.

DESCRIPTION OF EVENT

Surveillance testing of the hydrogen recombiner [BB] does not meet the Technical Specification requirement of testing in accordance with the manufacturer's recommendation as documented in the vendor technical information of record.

An independent line-by-line review of Technical Specification surveillance requirements and their im)lementing procedures was performed in response to a previous NRC commitment.

Durino tlat review process discre]ancies were found with station compliance to Technicai Specification 4.8.8.A. whic1 requires a low level and high level " readiness test in accordance with the manufacturers recommendations." A comparison was made between the manufacturer's recommended tests and the tests performed by the station.

Some of the control points and time intervals were not

)

consistent.

The tests in question are PT-15C. " Hydrogen Recombiner Low Level Readiness Test." that is performed semiannually, and TSS-15.6.105. " Hydrogen Recombiner High Level Readiness Test." that is ]erformed every five years. The low level readiness test is performed on a six mont, frequency to satisfy the requirements of the functional test.

During the initial investigation completed in November 1995.

the System Engineer determined that test procedures were consistent with the manufacturer's recommendation.

However, this was based on an understanding that the manufacturer's recommendations had changed during conversations between previous

{

System Engineers and vendor personnel.

Recent review as a result of increased emphasis on Technical Specificaticn compliance determined that the manufacturer's tests specified in the vendor technical information of record and station's tests are in conflict. The differences in heatup rates between vendor recommendation and the Zion test procedures are as follows:

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g:\\zler\\97012.ler(2)

LICENSEE EVENT REPORT (LER) TEXT CONTINUATION FACILITY NAME DOCKET NUMBER LER NUMBER PAGE YEAR SEO.

REV.

ZION NUCLEAR POWER STATION 0l5l0l0l0l2l9l5 9l7 0l1l2 0l0 0l4 0l5

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0F TEXT Energy Industry Identification System (EIIS) codes are identified in the text as [XX)

D.

SAFETY ANALYSIS

This inappropriate test criteria has minimal safety significance.

Per UFSAR Section 6.2.5.1. the Hydrogen Recombiner System is designed to control combustible gas i

(hydrogen and oxygen) in the Containment atmosphere during a Loss of Coolant Accident (LOCA).

Per UFSAR 15.6.5.6. the hydrogen recombiners are operated under the following conditions: hy M en concentration in the containment is less than 4% and containment pressure is be h I wig.

For the design basis LOCA this pressure is achieved after approximately 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br />.to the LOCA.

At 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br />, the postulated hydrogen concentration is well 4 Mw 4%.

The limit of 4% for hydrogen concentration in containment is not rea6 antil after greater than 30 days.

During a LOCA. the operation of the Hydrogen Recombiner is directed by the Technical Support Center as stated in Emergency Operating Procedure E-1 (Loss of Reactor or Secondary Coolant) step 21.

Operational guidance is provided in System Operating Instruction S0I-9G (Hydrogen Recombiner 0)eration After a LOCA).

These procedures provide guidance to connect the Hydrogen Recombiner based on plant conditions.

Per l

the UFSAR the recombiner may be connected any time after 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br /> following a LOCA and prior to approximately 30 days after a LOCA.

Consecuently, the discrepancy in the test criteria for heat up rates is not significant cue to the substantial amount of time available to align the recombiner for operation after an accident.

The operating temperature of the Hydrogen Recombiner is based on the auto-ignition temperature for hydrogen.

At a specific temperature, hydrogen and oxygen exothermically react and recombine to form water.

Based on the Condensed Chemical Dictionary (Tenth Edition revised by Gessner G. Hawley), this temperature is 1075 degrees F.

The minimum acceptable temperature in the Zion high level readiness test is 1100 degrees F.

Thus, the ability of the hydrogen recombiner to achieve the temperatures required to perform its function is confirmed by the Zion test criteria.

)

In addition, a review of nine low level performance tests showed that the equipment did res)ond in accordance with recommendations by the manufacturer.

Although the time to reac1600 F was not specifically documented in the tests, the tests require operators to record the system temperatures at 15 minute increments.

Eight of the nine tests showed that the heater outlet temperature was greater than 600 F at the i

thirty minute increment.

One test was not greater than 600 degress F at thirty minutes but was at 45 minutes.

A review of high level readiness tests found that the manufacturer's criteria specified in the vendor technical information manual of record were not met.

The time required to attain 1300 F was approximately two hours rather than the fifty minutes prescribed in the manufacturer's operating manual.

A review of the station's pre-operational test and the manufacturer's pre-shi) ment shop test indicated that a two hour heatup to 1300 F is expected.

The vendor las stated that the 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> heatup time is apr 7priate for the Zion recombiners.

However, the heater size installed at Zion is sufhcient to attain the temperature necessary to perform the required function and I

would remove hydrogen as required for post accident usage. Therefore, there was minimal safety impact on the plant.

9 :\\zler\\97012.ler(4) l

LICENSEE EVENT REPORT (LER) TEXT CONTINVATION FACILITY NAME DOCKET NUMBER LER NUMBER PAGE YEAR SEO.

REV.

ZION NUCLEAR POWER STATION 0l5l0l0l0l2l9l5 9l7 0l1l2 0l0 0l5 0l5

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0F TEXT Energy Industry Identification System (EIIS) codes are identified in the text as (XX)

L E.

CORRECTIVE ACTIONS

1.

The low level readiness test 3rocedure (PT-15C) will be changed prior to the next performance to include t1e manufacturer's acceptance criteria.

2.

The high level readiness test procedure (TSS-15.6.105) m ll be changed prior to the next performance to include the updated manufacturer s acceptance criteria.

3.

Technical Specification amendment policies in place now require detailed review and personal accountability for changes to the Technical Specification to ensure comph ance.

4.

The onsite vendor manual for the Hydrogen Recombiner will be updated to reflect the new vendor recommendations.

5.

Management's expectations for maintaining procedural and Technical Specification ccep iance were communicated to personnel during a series of meetings conducted in the fall of 1996.

6.

The results of the 1995 Technical Specification Compliance Self Assessment will be reviewed to ensure that other findings have been appropriately addressed.

F.

PREVIOUS EVENTS SEARCH AND ANALYSIS Emergency Diesel Generator Re? orts were issued late because Regulatory Assurance personnel misinterpreted the Regulatory Reporting Requirements.

Containment Sump Recirculation Level Calibration was placed on wrong inspection frequency due to Technical Specification misinterpretation.

There are other Licensee Event Reports such as the missed surveillance for Radiation Monitors and Steam Line Flow.

G.

COMPONENT FAILURE DATA

None r

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