ML18096A788

LER 91-038-01:on 911219,discovered That Max Concentration Release from 3,000 Gallon Ammonium Hydroxide Storage Tank Could Exceed Reg Guide 1.78 Guidelines.Caused by Design/Mfg Error.Temp Indicator Placed Near vessel.W/920604 Ltr

ML18096A788
Person / Time
Site:	Salem
Issue date:	06/04/1992
From:	POLLACK M J, VONDRA C A Public Service Enterprise Group
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
RTR-REGGD-01.078, RTR-REGGD-1.078 LER-91-038, LER-91-38, NUDOCS 9206240284
Download: ML18096A788 (7)

Text

e Public Service Electric and Gas Company P.O. Box 236 Hancpcks Bridge, New Jersey 08038 Salem Generating Station U. S. Nuclear Regulatory Commission Document Control Desk Washington, DC 20555

Dear Sir:

SALEM GENERATING STATION LICENSE NO. DPR-70 DOCKET NO. 50-272 UNIT NO. 1 June 4, 1992 SUPPLEMENTAL LICENSEE EVENT REPORT 91-038-01 This Licensee Event Report supplement is being submitted pursuant to the requirements of the Code of Federal Regulations lOCFR 50.73. Additional event assessment has shown that the event discussed in this LER is not reportable by either Code of Federal Regulations lOCFR 50.72 or lOCFR 50.73. MJP:pc Distribution 9206240284 920604 PDR ADOCK 05000272 S PDR The Energy People Sincerely yours, c. A Vondra General Manager -Salem Operations 95-2189 (10M) 12-89 NRC FORM 366 (6-89) U.S. NUCLEAR REGULATORY COMMISSION APPROVED OMB NO. 3150*0104 LICENSEE EVENT REPORT (LERI FACILITY NAME (1) Salem Generating Station -Unit 1 TITLE (4) EXPIRES: 4/30/92 ESTIMATED BURDEN PER RESPONSE TO COMPLY WTH THIS INFORMATION COLLECTION REQUEST: 50.0 HRS. FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO THE RECORDS AND REPORTS MANAGEMENT BRANCH (P-530), U.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555, AND TO THE PAPERWORK REDUCTION PROJECT (3150-0104), OFFICE OF MANAGEMENT AND BUDGET, WASHINGTON, DC 20503. l DOCKET NUMBER (2). I PAGE 131 o 15 Io Io Io 12 I 712 1 loF 0 16 Control Room Concern From Postulated Ammonium Release EVENT DATE (5) LEA NUMBER (61 REPORT DATE (7) OTHER FACILITIES INVOLVED (BJ MONTH DAY YEAR YEAR

()

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MONTH DAY YEAR FACILITY NAMES DOCKET NUMBER(SI Salem Unit 2 o 1 s I o I o I o I 3 11 11 1 12 119 9 1 911 -oj 3 js -o I 1 o j 6 oj 4 9 I 2 OPERATING MODE (BJ THIS REPORT IS SUBMITTED PURSUANT TO THE RcOUIREMENTS OF 10 CFR §: !Ch*ck ono or mor* of th* following)

(11) 1 20.405(c) 20.405(1)(1 J(i) --.....__ POWER I LEVEL 1. Q Q ....._ 1101 I I 20.405111!1 lliil ,_ 50.38(c)(1)

-50.3B(cJ(2)

....._ 50.73(1)(2)(v) 73.71 (c) 50.73(1)(2) (viii 50.73(1)(211viii)(A) 50.73(1) (2) (viii I (BJ 50.73(1)(2Jlx)

....._ X OTHER ISP6cify in Abstract ""--btJlow and in Tt1xt. NRC Form 366A) NAME 20.406(1)(1

)(iii) 20.406(1)(1

)(iv) 20.40511111 JM -50.73(1J(2)(i)

-....._ 60.73(1)(2J(ii)

-....._ 50.73(11(2Jlii1J LICENSEE CONTACT FDR THIS LER (12) Informataion Only TELEPHONE NUMBER AREA CODE M. J. Pollack -LER Coordinator 6 I 0 19 3 13 I 9 I -12 I 0 12 12 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13) CAUSE SYSTEM COMPONENT I I I I I I I I MANUFAC* TUR ER I I I I I I SUPPLEMENTAL REPORT EXPECTED (14) I YES (If v*s. compl*t* EXPECTED SUBMISSION DA TE) ABSTRACT (Limit to 1400 spaces, i.t1., approximately fifttJtJn sing/s-spaca typt1writtttn lines) (16) CAUSE SYSTEM I I COMPONENT MANUFAC* TUR ER I I I I I I I I I I I I EXPECTED SUBMISSION DATE (151 MONTH DAY YEAR I I I On 12/19/91, an interim calculation concluded that a Control Room habitability concern was possible, due to postulated failure of a 3000 gallon ammonium hydroxide storage tank. In accordance with Regulatory Guide 1.78, the maximum concentration release was postulated from a catastrophic failure of the largest storage tank of ammonium hydroxide (27.5 wt%). The liquid ammonium hydroxide would vaporize to ammonia upon release, exhaust to the environment, and disperse to the Control Room air supply intakes. The calculation indicated that the Regulatory Guide 1.78 guideline could be exceeded.

Immediate actions were taken to mitigate the potential consequences.

Continued evaluation has shown that the interim calculation did not accurately simulate plant conditions.

A more appropriate calculational method was since used which shows that PSE&G does conform to Regulatory Guide 1.78. The root cause of not addressing the ammonium hydroxide concern in the Final Safety Analysis Report (FSAR) is design, manufacturing, constuction/installation error. Compensatory actions were taken to ensure control room habitability under postulated accident conditions when the concern was first identified.

A survey for additional hazardous chemical on-site storage concerns was conducted.

An Engineering Evaluation, including a 10CFR50.59 Safety Evaluation, was completed addressing ammonium hydroxide and other applicable hazardous chemical issues. A change to the UFSAR has been initiated.

The chemical control program and procedures were evaluated and applicable procedure revisions made. NRC Form 366 (6-89)

LICENSEE EVENT REPORT (LER) TEXT CONTINUATION Salem Generating Station Unit 1 DOCKET NUMBER 5000272 PLANT AND SYSTEM IDENTIFICATION:

Westinghouse

-Pressurized Water Reactor LER NUMBER 91-038-01 PAGE 2 of 6 Energy Industry Identification System (EIIS) codes are identified in the text as {xx} IDENTIFICATION OF OCCURRENCE:

Control Room habitability concern from postulated ammonium hydroxide release Discovery Date: 12/19/91 Report Date: 6/4/92 This report was initiated by Incident Report No.91-920. This LER Supplement retracts the identification of reportability per Code of Federal Regulations 10CFR50.72 or lOCFR 50.73 based on subsequent investigation of the event. CONDITIONS PRIOR TO OCCURRENCE:

Unit 1: Unit 2: Mode 1 Reaftor Power 100% -Unit Load 1158 MWe Defueled -6 li Refueling in progress DESCRIPTION OF OCCURRENCE:

On December 19, 1991, an interim calculation concluded that a Control Room habitability concern was possible due to postulated failure of a 3000 gallon capacity ammonium hydroxide storage tank (1CFE24), located on 120 1 El. Unit 1 Turbine Building.

The analysis was prepared by Stone & Webster Engineering Corporation (SWEC) using the "VAPOR" computer program. Ammonium hydroxide is used to maintain secondary plant pH control (i.e., Chemical Feed System {KD}). In accordance with Regulatory Guide 1.78, the maximum concentration release was postulated from a catastrophic failure of the largest storage tank of ammonium hydroxide (27.5 wt%). It was assumed that the liquid ammonium hydroxide would vaporize to ammonia upon release, exhaust to the environment (from the Turbine Building Ventilation System), and disperse to the Control Room air supply intakes. The VAPOR calculation indicated that the Regulatory Guide 1.78 toxic limit for ammonia (100 ppm) would be exceeded.

On December 19, 1991, at 1530 hours0.0177 days <br />0.425 hours <br />0.00253 weeks <br />5.82165e-4 months <br />, the Nuclear Regulatory Commission (NRC) was notified in accordance with Code of Federal Regulations 10CFR50.72(b)

(1) (ii). Continued evaluation utilizing the more representative computer model "CHARM", after it had been validated and verified in accordance with PSE&G QA and Engineering Department procedures, has determined that both Salem Units 1 & 2 would have remained habitable per Regulatory LICENSEE EVENT REPORT (LER) TEXT CONTINUATION Salem Generating Station Unit 1 DOCKET NUMBER 5000272 DESCRIPTION OF OCCURRENCE: (cont'd) Guide 1.78. APPARENT CAUSE OF OCCURRENCE LER NUMBER 91-038-01 PAGE 3 of 6 The root cause of not addressing the ammonium hydroxide concern in the Final Safety Analysis Report (FSAR) is design, manufacturing, constuction/installation error. The original design identified the current storage tank used for secondary water chemistry control as containing morpholine.

Prior to issuance of an operating license, secondary water treatment was changed and the tank designated to store ammonium hydroxide.

FSAR Section 10.2.1.6, "Chemical Feed system", and Figure 10.2-9, "Feedwater Chemical Treatment System" were revised (by Amendment 37 dated April 5, 1976). No discussion of control room habitability for ammonium hydroxide was included in the FSAR. Discussions involve other.hazardous chemicals, airborne radiation, smoke and fire. Because ammonium hydroxide was not specifically identified as a toxic chemical in Regulatory Guide 1.78 or any of its references, it was concluded that it was not considered a hazardous chemical for control Room habitability evaluations.

Additionally, the original FSAR was developed in accordance with the June 30, 1966 AEC Guide for the Organization and Contents of Safety Analysis Reports and AEC General Design Criteria dated July 10, 1967. These documents did not require review and evaluation of site hazards to the degree required after Salem was licensed.

The FSAR made no commitment to Regulatory Guide 1.78 dated June 1974, but did evaluate the effects from accidents involving potential hazardous materials stored on-site as a result of FSAR Review Question 2.11. During the licensing of Unit 2 the response to FSAR Review Question 9.60 and NUREG-0737 TMI Action Item III.D.3.4 stated that plant and site were evaluated for compliance with Regulatory Guide 1.78 and Standard Review Plan Sections 2.2 and 6.4. A preliminary assessment, conducted in September 1991 utilizing the Radian Corporation CHARM code, supported the conclusion that the Control Room habitability would not exceed the two (2) minute criteria contained in Regulatory Guide 1.78 upon failure of the ammonium hydroxide storage tank. However, CHARM could not be validated and verified in time to support PSE&Gs schedule to reply to an NRC inspection open item. An alternate contractor was selected (SWEC). They utilized the VAPOR code which identified the safety concern as discussed above. PSE&G proactively took immediate conservative actions. The VAPOR code was subsequently determined to be too conservative.

Evaluations continued with a more representative model (the CHARM code). Once the CHARM code was validated and verified, the LICENSEE EVENT REPORT (LER) TEXT CONTINUATION Salem Generating Station Unit 1 APPARENT CAUSE OF OCCURRENCE:

DOCKET NUMBER 5000272 (cont'd) LER NUMBER 91-038-01 PAGE 4 of 6 10CFR50.59 Safety Evaluations were updated. These evaluations concluded that the guidelines for Control Room habitability, per Regulatory Guide 1.78, had been met. ANALYSIS OF OCCURRENCE In July 1980, a review and evaluation of the plant and site was conducted per NUREG-0737 Action Item III.D.3.4.

The Action Item required identification and evaluation of potential hazardous material and a determination that the control room was adequately protected.

The review concluded that the control room was adequately protected since "no chemical hazards exist" based on previous responses to NRC inquiries.

The Updated Final Safety Analysis Report {UFSAR) does not include ammonium hydroxide on the stored hazardous chemical list (UFSAR Section 2.2). UFSAR Section 6.4, does not address ammonium hydroxide impact on control room habitability.

Also, the AEC standard format (dated 1966) did not require discussions of control room habitability.

During the Unit 2 FSAR review (to support Unit 2 licensing), NRC Question 9.60 did ask how Salem's design complied with Regulatory Guide 1.78, but it was asked relative to off-site river accidents.

When the ammonium hydroxide concern was first identified in September 1991 (reference NRC Inspection Report 50-272/91-25, dated September 26, 1991) an assessment of control room habitability was initiated using the "CHARM" computer program. Results indicated that the toxic limit for ammonia gas, listed in Regulatory guide 1.78, would be met. The CHARM methodology is used by industries and regulatory agencies for evaluating chemical spills. Since the computer code was being utilized for an "important to safety" calculation, validation and verification was required.

Radian Corp. could not comply with PSE&G's NRC Open Item response schedule.

An alternate contractor

{SWEC) was selected, who used the VAPOR code which identified a safety concern. VAPOR is based on methodology which utilizes very conservative assumptions.

The VAPOR program determined that the two (2) minute toxic limit of Regulatory Guide 1.78 could be exceeded.

Hope Creek Generating Station, located on the same site as Salem Generating Station, was notified of the Salem Control Room habitability concern for potential impact at Hope Creek Generating Station. During the approval cycle for the calculation, PSE&G questioned the VAPOR model assumptions, associated with plant conditions, and continued the evaluation by qualifying the CHARM code per the Nuclear Department Engineering procedures.

The CHARM model more accurately

,-LICENSEE EVENT REPORT (LER) TEXT CONTINUATION Salem Generating Station Unit 1 ANALYSIS OF OCCURRENCE:

DOCKET NUMBER 5000272 (cont'd) LER NUMBER 91-038-01 PAGE 5 of 6 reflects actual plant conditions by including the jet effect from the roof top exhaust ventilators and the buoyancy effect of the lighter resultant mixture of ammonia gas and warmed Turbine Building air. Use of CHARM, for source term postulated toxic gas concentrations at the Control Room Ventilation intakes and the final toxic gas buildup concentration calculation in the Control Room proper, produced results .that remained within the guidelines of Regulatory Guide 1.78. The Salem Unit Nos. 1 and 2 and Hope creek Control Rooms would not become uninhabitable, per CHARM code results and routine operating practices.

Therefore, the health and safety of the public was not affected.

CORRECTIVE ACTION The following compensatory actions were taken to ensure control room habitability under postulated accident conditions (per VAPOR): 1. A temperature indicator (with chart recorder) was placed in the proximity of the storage vessel to monitor temperature in the tank area. Ammonia release is temperature dependent (i.e., 27.5 wt% ammonium hydroxide solution has a boiling point of 82°F)

• 2. The maximum allowable storage volumes for 27.5 wt% ammonium hydroxide were determined for temperatures up to 75°F and transmitted to the Salem Operations and Chemistry departments.

3. Precautionary administrative controls, for tanker truck delivery, have been initiated as per revision of Chemistry procedure SC.CH-AD.ZZ-0474, "Receipt of Ammonium Hydroxide Tank Trucks". With the use of the CHARM code, the need to continue the above corrective actions will be assessed.

A survey for additional hazardous chemical on-site storage concerns was conducted.

Results identified two (2) additional chemicals with the potential to impact Control Room habitability, 35 wt% hydrazine and 50 wt% sodium hydroxide.

Preliminary assessment indicates no impact on Control Room habitability.

Further corrective actions were taken to ensure Control Room habitability even though present calculations show that control Room habitability is not in question:

1. An Engineering Evaluation, A-O-ZZ-SEE-0659 "Engineering Evaluation for the Use of 15 Wt% Ammonium Hydroxide at the Salem Generating Station Unit Nos. 1 & 2 11 , was performed' LICENSEE EVENT REPORT (LER) TEXT CONTINUATION Salem Generating station Unit 1 DOCKET NUMBER 5000272 LER NUMBER 91-038-01 PAGE 6 of 6 CORRECTIVE ACTION (cont'd) MJP:pc and issued to allow a transition to 15 Wt% ammonium hydroxide (from 27.5 Wt%), which is less affected by the temperature range experienced by the storage tanks. 2. Operators were trained to identify the odor of ammonia. Also, ammonia was added to the annual olfactory recognition testing performed by the Medical Department on the licensed operators.

3. An Abnormal Operating Procedure, SC.OP-AB.CR-0003(Q), "Toxic Gas Release", was issued. 4. NC.NA-AP.ZZ-0019(Q), "Procurement of Materials and Services" and NC.NA-AP.ZZ-0038(Q), "The Chemical Control Program" were reviewed.

NC.NA-AP.ZZ-0038(Q) was revised concerning potential impact of chemicals on Control Room habitability.

5. A revision was made to procedure NC.DE-AP.ZZ-OOOl(Q) "Design Bases/Input" to address the possible impact from hazardous chemicals, used in conjunction with or added by Design Changes, on Control Room habitability.

6. A 10CFR50.59 Safety Evaluation was issued, in conjunction with SAR Change Notice 92-07. The UFSAR will be revised to identify the evaluation showing that the guidelines of Regulatory Guide 1.78 are met. General Manager -Salem Operations SORC Mtg.92-064