ML18102A283

LER 96-002-00:on 960701,waste Gas Decay Tank Oxygen Concentration Exceeded TS 3.11.2.5 Limit.Caused by Poor Wording & Interpretation of Ts.Oxygen Concentration Levels Restored to TS Limit & Amend to TS Submitted

ML18102A283
Person / Time
Site:	Salem
Issue date:	07/26/1996
From:	Hassler D Public Service Enterprise Group
To:
Shared Package
ML18102A282	List: ML18102A281 ML18102A283
References
LER-96-002-02, LER-96-2-2, NUDOCS 9608050198
Download: ML18102A283 (4)

Text

NRCFORM366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB NO. 3150-0104 (4-95) EXPIRES 04130198 ESTIMATED BURDEN PER RESPONSE TO COMPLY WITH THIS MANDATORY INFORMATION COLLECTION REQUEST: 50.0 HRS. REPORTED LESSONS LEARNED ARE INCORPORATED INTO THE LICENSEE EVENT REPORT (LER) LICENSING PROCESS AND FED BACK TO INDUSTRY.

FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO THE INFORMATION (See reverse for required number of AND RECORDS MANAGEMENT BRANCH (HI NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC , AND TO digits/characters for each block) THE PAPERWORK REDUCTION PROJECT OFFICE OF MANAGEMENT AND BUDGET, WASHINGTON, 20503. FACILITY NAME (1) DOCKET NUllBER (2) PAOE(3) SALEM GENERATING STATION, UNIT 2 05000311 1 OF4 TITLE (4) Waste Gas Decay Tank Oxygen Concentration Exceeded Technical Specifications Limit EVENT DATE (5) LER NUMBER (6) REPORT DATE (7) OTHER FACILITIES INVOLVED (8) I FACILITY NAME DOCKET NUMBER MONTH DAY YEAR YEAR SEQUENTIAL I REVISION MONTH DAY YEAR NUMBER NUMBER Salem Unlt1 05000272 07 01 96 96 002 00 07 26 96 FACILITY NAME DOCKET NUMBER --05000 OPERATING THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check one or more) (11) MODE (9) 20.2201(b) 20.2203(a)(2)(v) x 50. 73(a)(2)(i)

50. 73(a)(2)(viii)

POWER 20.2203(a)(1) 20.2203(a)(3)(i)

50. 73(a)(2)(ii)

50. 73(a)(2)(x)

LEVEL (10) 20.2203(a)(2)(i) 20.2203(a)(3)(ii)

50. 73(a)(2)(iii) 73.71 -20.2203(a)(2)(ii) 20.2203(a)(4)

50. 73(a)(2)(iv)

OTHER 20.2203(a)(2)(iii) 50.36(c)(1)

50. 73(a)(2)(v)

Abstract below or In C Form 366A 20.2203(a)(2)(iv) 50.36(c)(2)

50. 73(a)(2)(vii)

LICENSEE CONTACT FOR THIS LER (12) NAME TELEPHONE NUllBER (Include Ara* Code) Dennis v. Hassler, LER Coordinator 609-339-1989 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13) CAUSE SYSTEM COMPONENT MANUFACTURER REPORTABLE I CAUSE SYSTEll COMPONENT MANUFACTURER REPORTABLE TONPRDS TONPRDS SUPPLEMENTAL REPORT EXPECTED (14) EXPECTED MONTH DAY YEAR x IYES INO SUBMISSION 09 16 96 (If yea, complete EXPECTED SUBMISSION DATE). DATE(15) ABSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines) (16) On April 24, 1996, the Unit 2 Waste Gas System was taken out of service for maintenance and was vented to atmosphere.

Technical Specification 3.11.2.5 requires the oxygen concentration to be less than 2% at all times. This Technical Specification was not considered applicable at the time because the system was not being used for waste gas storage. However, further evaluation by Plant Management and Licensing personnel determined that this interpretation was not correct. Contrary to the Technical Specification, the concentration of oxygen was greater than 2% for greater than 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />. In addition, the concentration of oxygen was greater than 4% and was not reduced immediately.

The cause of the occurrence was determined to be poor wording and interpretation of the Technical Specifications.

Corrective actions include restoring the Oxygen concentration levels to Technical Specifications limit at Salem Unit 2. Oxygen concentration levels will be restored at Unit 1 in accordance with a maintenance schedule currently being developed.

The need to comply with the intent and exact wording of the Technical Specifications has been corrmunicated to the operating crews. Technical Specification administrative/wording problems will be resolved by submitting a License Change Request. This event is reportable in accordance with 10 CFR 73(a) (2) (i) (B)' any condition prohibited by the plant's Technical Specifications.

9608050198 960729 PDR ADOCK 05000311 5 PDR NRC FORM 366A (4-95) U.S. NUCLEAR REGULATORY COMMISSION LICENSEE EVENT REPORT (LER) TEXT CONTINUATION FACILITY NAME (1) DOCKET NUMBER (2) LER NUMBER (8) PAGE (3) SALEM GENERATING STATION UNIT 2 96 -002 -00 TEXT (If more apace i* required, use additional copies of NRC Form 366A) (17) PLANT AND SYSTEM IDENTIFICATION Westinghouse

-Pressurized Water Reactor Waste Gas Disposal {WE/-}*

• Energy Industry Identification System (EIIS) codes and component function codes appear as (SS/CCC) CONDITIONS PRIOR.TO OCCURRENCE At the time of identification, Salem Units 1 and 2 were shutdown and defueled.

DESCRIPTION OF OCCURRENCE On April 24, 1996, the Unit 2 waste Gas System was taken out of service for maintenance and was vented to atmosphere.

Technical Specification 3.11.2.5 was not considered applicable at the time because the system was not being used for waste gas storage. However, further evaluation by Plant Management and Licensing personnel determined that this interpretation was not correct. ,The Technical Specification 3.11.2.5 Limiting Condition for Operation (LCO) states "the concentration of oxygen in the waste gas holdup system shall be limited to less than or equal to 2% by volume." If this condition is not met, the actions required are to: (1) With the concentration of oxygen in the waste gas holdup system greater than 2% by volume but less than or equal to 4% by volume, reduce the oxygen concentration to within limits within 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />; or (2) With the concentration of oxygen in the waste gas holdup system greater than 4% by volume immediately suspend all additions of waste gasses to the system and reduce the concentration of oxygen to less than or equal to 2% by volume without delay. The Technical Specifications state that these actions are applicable "at all times." As such, the following non-compliance issues existed from April 24 to July 10, 1996, at Unit 2: (1) The concentration of oxygen was greater than 2% for greater than 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />. In addition the concentration of oxygen was greater than 4% and was not reduced without delay. (2) All waste gas additions to system were not secured when oxygen concentrations exceeded 4%. It was also noted, however, that isolation of waste gas additions from all of the decay tanks once the system is in operation may not be practical.

This could result in uncontrolled waste gas release into the auxiliary building.

This Technical Specification compliance problem is also applicable to Unit 1. The Unit 1 Waste Gas System was taken out of service on August 26, 1995, and the gas decay tanks were vented to atmosphere. Unit 1 tanks are still vented to atmosphere; however, a maintenance schedule is being developed to return oxygen concentration in the tanks to NRC FORM 366A (4-95)

NRC FORM 366A (4-95) FACILITY NAME (1) U.S. NUCLEAR REGULATORY COMMISSION LICENSEE EVENT REPORT (LER) TEXT CONTINUATION DOCKET NUMBER (2) LER NUMBER (6) PAGE (3) 05000311 YEAR I 3 OF 4 SALEM GENERATING STATION UNIT 2 96 -002 00 TEXT (If more space is required, use additional copies of NRC Form 366A) (17) DESCRIPTION OF OCCURRENCE The issues identified above were discovered during the period from July 1 to July 24, 1996. The issue identified on July 1 was that oxygen levels had exceeded 2% for greater than forty eight hours. On July 24, during investigation of the original issue, it was determined that the Technical Specification should apply even when the system is not being used for waste gas storage. Although not validated, similar occurrences may have occurred in the past. CAUSE OF OCCURRENCE The cause of the occurrence was determined to be poor wording and interpretation of the Technical Specifications.

Specific issues were: (1) An administrative error was created when corrections to Technical Specification 3.11.2.5 Amendments 64 and 36 inadvertently removed hydrogen applicability wording in the LCO. On December 5, 1984, the Salem Units 1 and 2 Technical Specifications were amended (Amendments 59 and 28, respectively) to add Section 11 "Radioactive Effluents Explosive Gas Mixture." The Technical Specification 3.11.2.5 Limiting Condition for Operation (LCO) stated that "the concentration of oxygen in the waste gas holdup system shall be limited to less than or equal to 2% by volume whenever the hydrogen concentration exceeds 4% by volume." On May 30, 1985, Technical Specification 3.11.2.5 Amendments 64 and 36 were issued to correct typographical errors, but did not change the LCO wording " ..... whenever the hydrogen concentration exceeds 4% by volume." Less than a month later (June 21, 1985), the NRC issued a correction to Amendments 64 and 36 which inadvertently removed the LCO hydrogen applicability wording. The. amendments' Safety Evaluation did not address the reason for the hydrogen applicability wording change. PSE&G did not identify the discrepancy.

Since the systems were vented to atmosphere and hydrogen was not being used in the plant, use of the hydrogen exclusion would have negated the need to enter the action statements of Technical Specification 3.11.2.5.

(2) Technical Specification 3.11.2.5 was poorly interpreted to apply at all times when the system was being used for waste gas storage, rather than at all times. This is also a wording problem because the specification should specify at all times when the system was being used for waste gas storage, to allow for maintenance activities.

(3) Technical Specification 3.11.2.5 was poorly interpreted to apply to individual decay tanks vice all of the tanks at the same time. This is also a wording problem because the waste gas holdup tanks should be treated as individual units, as described in the Salem UFSAR. Otherwise, uncontrolled waste gas release into the auxiliary building could result. NRC FORM 366A (4-95}

... " NRC FORM 366A (4-95) U.S. NUCLEAR REGULATORY COMMISSION LICENSEE EVENT REPORT (LER) TEXT CONTINUATION FACILITY NAME (1) DOCKET NUMBER (2) LER NUMBER (8) PAGE (3) 05000311 YEAR I 4 OF 4 SALEM GENERATING STATION UNIT 2 96 -002 00 TEXT (If more space is required, use additional copies of NRC Form 366A) (17) PRIOR SIMILAR OCCURRENCES In the past two years there has been one similar LER. LER 311/96-003-00 identified an occurrence where an erroneous determination was made regarding Technical Specification applicability The Technical Specifications contained a surveillance for an auto-start feature in the FHB Ventilation System that was not installed.

Corrective actions were to install the auto-start feature and the continuation of the Technical Specification Improvement Project. SAFETY CONSEQUENCES AND IMPLICATIONS During the period when the oxygen concentration in the Waste Gas System exceeded the Technical Specifications Limiting Condition for Operation, the system was vented to atmosphere, or was being returned to service following an extended system outage. Consequently, there was no concentration of hydrogen which would create the potential for an explosive gas mixture with oxygen. The build up of hydrogen under the current condition is not credible.

Therefore, there was no actual safety significance with this occurrence.

The health and safety of the public was not affected.

CORRECTIVE ACTION 1. Oxygen concentration levels were restored to Technical Specifications requirements at Unit 2. 2. Oxygen concentration levels will be restored at Unit 1 expeditiously in accordance with the maintenance schedule currently being developed.

This LER will be supplemented when oxygen levels are restored.

3. The problems with this Technical Specification have been communicated to the operating crews. Isolation of waste gas from all holdup tanks, if oxygen levels exceed 4 percent, will carefully evaluated since such action may cause uncontrolled release of waste gas into the Auxiliary Building.

If isolation of all waste gas is not practical, the tank with the high oxygen levels will be isolated and purged, and another tank will be placed in service, as described in the UFSAR. If this occurs prior to a change to the Technical Specifications, a supplement to this LER will be submitted.

4. Operations Management has emphasized the need to comply with the intent and the exact wording of the Technical Specifications, and to immediately address any issues where the intent and the wording are in conflict.

5. A request to resolve Technical Specification 3.11.2.5 administrative/wording problems will be submitted by August 15, 1996. NRC FORM 366A (4-95)