ML20245K274

Insp Rept 50-344/89-18 on 890712-14.Violations Noted.Major Areas Inspected:Uresolved Item Re Licensee High Pressure Hydrogen & Nitrogen Storage Facility at Plant & Review of Licensee Implementation of NRC Info Notice 87-020

ML20245K274
Person / Time
Site:	Trojan File:Portland General Electric icon.png
Issue date:	08/03/1989
From:	Garcia E, Hooker C, Andrea Johnson NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
To:
Shared Package
ML20245K259	List: ML20245K254 ML20245K262 ML20245K274
References
50-344-89-18, IEIN-87-020, IEIN-87-20, NUDOCS 8908180381
Download: ML20245K274 (9)

See also: IR 05000344/1989018

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V. S. NUCLEAR REGULATORY COMMISSION

REGION V

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Report No. 50-344/89-18

Docket No. 50-344'

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Licensee: Portland General Electric Company

121 S.W. Salmon Street

Portland, Oregon 97204

Facility Name: Trojan Nuclear Plant

Inspection at:' Portland and Rainier, Oregon

Inspection Conducted: July 12-14 1989

Inspectors: 5!(ff ,

E. A Ho e 1 Facilities Inspector Date i ned

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A. D. Johns

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, Regional Enforcement Officer Dfite' Sighed

Approved: . .

8/

E. M. Garcia, Acting Chief Date' Sigried

Facilities Radiological Protection Section

Summary:

a. Areas Inspected: ,

This was a special, unannounced inspection of an unresolved item

J (50-344/89-07-04) concerning the licensee's high: pressure hydrogen i

> , and nitrogen storage facility at the Trojan Nuclear Plant. In

addition the inspection included a review of the licensee's

evaluation and implementation of recommendations associated with NRC

Information Notice (IN) 87-20, Hydrogen Leak in Auxiliary Building,

. dated April 20, 1987. Inspection procedures 30703 and 92701 were-

addressed.

h b. Results:

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One potential safety problem associated with. bulk storage of

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hydrogen on the roof of the control building had not been ,

- identified, evaluated or resolved as a result of the licensee's

review associated with NRC Information Notice 87-20. In addition,

the licensee's review and evaluation of the matters discussed in the

Information Notice were narrow in scope and not timely in completion.

Accordingly, one violation of 10 CFR 50, Appendix B, Criterion XVI

was idectified, paragraph 2.

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DR sDOCK 0500o344

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DETAILS

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M - 1. . Persons Contacted

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Lice'nsee

• D. WL Cockfield, Vice President, Nuclear

. C' P. Yundt, General Manager, Trojan

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2 *A.L N. Roller, Manager, Nuclear 71 ant Engineering -(NPE); <

R. M. Nelson, Manager, Nuclear Safety & Regulation' Department (NSRD)

D.;R. Swanson, Manager, Nuclear: Safety Branch-(NSB)

• M..W. Hoffmann, Branch Manager, Mechanical Engineering

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• S. A.'Bauer,-Branch Manager, Nuclear Regulation

D. W. Swan, Manager,-Technical Services'(TSM)

• W. 'J. Williams, Jr.,' Compliance Engineer

A. P. Corral, Nuclear Safety Engineer-

J. D. Guberski, Compliance Engineer "

D. R. Pearson, Specialist III, Nuclear Operations

M. H. Malmros, Supervisor, Instrument _ & Control Maintenance

, 'G'; Van'Bladeren, Supervisor, Mechanical Maintenance Engineering

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.W. Monroe, Systems Engineer

NRC Resident Inspector

jR. C. Barr , Senior Resident Inspector

~* Denotes individuals' attending the exit interview on July 14, 1989.

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.In additien to the individuals noted above, the inspectors met and held ,

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discussions with other' members of the licensee's staff. 4

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- 2. Followup (92701)

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Background ',

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Inspection' Report No. '50-344/89-07, dated May 23, 1989, describes several [# . _( _

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rNRC Region.V concerns regarding potential safety problems with the-

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1ocation of the' licensee's hydrogen and nitrogen storage facility

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(seismic Class II design) on the roof of the control room. Concerns sere

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also raised with the location of the hydrogen system's fill station that #

t was' located on.the exterior of the auxiliary building wall. The

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"l . potential safety problems included:. (1) The potential for introducing an a

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explosive or flammable gas mixture of hydrogen into the control room via

o the control room ventilation system; (2) nitrogen leakage into the

L; control room ventilation system that could cause asphyxiation of the

. operators; (3) detonation of a hydrogen tank resulting in damage to the

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roof of the control room that could-have an effect on the performance of i

safety-related equipment; and (4) an explosion of the hydrogen delivery

truck that could result in damage to safety-related components in the

auxiliary building in the vicinity of the fill station. The potential

safety problems were identified based on the guidance provided in EPRI

NP-5283-SR-A., Special Report, September 1987, Guidelines for Permanent

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F,%  %' BWR' Hydrogen' Water Chemistry Installations-1987 Revision; IN 87-20 3 4

j. , n .C indicated that the NRC was reviewing this EPRI/BWROG topical report. As. . , 1

L  : 3.3 a' result'of these potential safety: problems, the NRC issued IN 89-44, y '

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A y; . ii- l Hydrogen Storage on the Roof of the Control Room, dated April-27, 19894A ij

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Chronology?of Events- _

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Based'on a review of licensee records,L the-inspectors made the following

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g' 7: d. The licensee's Corporate Office in Portland, OR, received IN 87-20 f

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on May 1, 1987, and forwarded it to the NSRD, also of the Corporatef

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J Office; for review. An individual (0ERP Coordinator) in the NSB of. -

'the NSRD that was assigned the responsibility for the initial review

t land coordination of such documents, initiated Operational Assessment'

q ReviewForml(0AR)87-29.

The OERP Coordinator completed Part A,. Sections I and II, of 0AR

87-29 on May 2, 1987, marking: II.A. to note that IN.87-20 was

applicable to Trojan;Section II, item C " Conditionally

1 Significant;" II.F. " Investigate and recommend corrective action,

if any" and provided the following comment " Recommend that NPE

verify that Trojan's design-precludes excess hydrogen accumulation

in the Control / Aux Building / Fuel Building complex. The proper

sizing'of the excess flow valves shown on P&ID M-232/Rev 23 in

combination with adequate building ventilation would appear to

alleviate the. problem at Trojan." Item II.G. " Evaluation Priority"

assigned a target due date of July 3,.1987, and item II.H. assigned

NPE as the evaluation ~ action group. On May 3, 1987, the NSB Manager

approved the initial review and forwarded 0AR 87-29 to NPE, located

in the Corporate Office

NPE completed their evaluation (Part A,Section III and Part B) of

OAR 87-29 and submitted a request for design change (RDC), Startup

No.74,,datedOctober7,1987,andmemorandum(ANR-1246-87M), dated

October 8, 1987, with their recommendations to NSRD.

The memorandum (ANR-1246-87M) recommended that PGE 1012, Fire

Protection Plan Program Description, be revised to include the

effects of a hydrogen gas supply line leak.in the Auxiliary and Fuel

Buildings. The memorandum noted that the reason for the revision

was that PGE-1012 did not adequately address the possibility of

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leaking hydrogen building up to flammability limits (4-75 percent by

volume). The memorandum also stated: 1

" Evaluation of 0AR 87-29 concluded that ventilation in rooms

carrying hydrogen lines in the Auxiliary / Fuel Buildings is ,

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inadequate for the existing hydrogen gas supply excess flow  !

valve (GS-037, -038, -162) closure setpoint.

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For example, ventilation in the volume control tank (VCT) room

is only 300 cubic feet per minute (cfm). Excess flow valve

, closure setpoint is 600 standard cubic feet per minute (scfm). ,

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Flammability limits could:be. reached very quickly if a leak.

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4 , , . The 600 scfm flow rate was subsequently determined to be. incorrect,

as discussed later in this report. .

The memorandum furti,+r ,uoted from the Standard Review Plan

-(NUREG-0800):

, " Hydrogen lines in safety-related areas should be either'

designed to Seismic Class 1 requirements.. or sleeved such that

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l- the outer pipe is directly vented to the outside, or should be

equipped with excess flow valves so that in case of a line'

C break the hydrogen concentration in the affected areas will not-

. exceed 2. percent."

.0AR (Part B)' Evaluation Criteria Checklist,Section III.B., states:

L"Could the identified problem:... Item 7. Degrade the facilities'

' fire protectionLprogram or fire-fighting capability?... Item 13.

' Result in unsafe' conditions not readily identifiable to Plant

Operators."-

These were marked yes.

RDC, Startup No. 7.4, recommended that: (1) to increase the '

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ventilation in the rooms carrying hydrogen lines in'the

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% Auxiliary / Fuel. Buildings; or (2) replace hydrogen gas system excess ,-

• n . flow valves <that have'a lower closure set point and (3) install- ,

"] 'e1  : hydrogen sensing equipment equipment in the Auxiliary / Fuel Bui.1 ding

i s ' rooms carrying hydrogen. lines-to detect hydrogen leakage. A,

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7 r The. Manager, NSRD approved 0AR 87-29 on November 19, 1987, and ~, '

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cforwarded it to the TSM at the Trojan Plant for review and approval.

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W The TSM reviewed the 0AR package and returned it to NPE on November

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x25,11987, with the following note attached:

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j' "I see this as~a case.of over correcting for a potential ,'_ 1

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problem of low probability and questionable safety concern. 1

m' Need exists as I see it to look more closely for a cost  !

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effective solution."

The OAR was reassigned to NSRD and, on December 8, 1988, an 4

-individual from the Nuclear Safety group signed off as completing  !

the re-evaluation of 0AR 87-29. This subsequent evaluation

recommended: (1) to delete the previous recommendation to increase ,

the ventilation flows; (2) instead of replacing the hydrogen gas .l

supply excess flow valves, install a new excess flow valve in the 1

hydrogen line on the roof of the Auxiliary Building that supplies )

the VCT; (3) delete the previous recommendation to install hydrogen

sensing equipment in the Auxiliary / Fuel Buildings, since the system

engineer performs daily reviews of hydroren tank pressures; and (4)

revise PGE-1012 as previously recommended. J

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The final approval process for 0AR 87-29 was completed and signed-

off_by the Vice President, Nuclear, on April 4, 1989. The target'

> due date to revise PGE-1012 was' July l', 1989, and the target due

date to install the new excess flow control valve was July 1, 1990.

Based on the above review, interviews with the individuals that performed

0AR 87-29 reviews and evaluations, and other document reviews, the

inspectors made the following additional observations:

The individual that initiated 0AR 87-29 and performed the screening

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(Attachment A, Sections I and II) informed the inspectors that: (1)

the scope of his review consisted of the topic addressed in IN 87-20

only and did not, and typically would not, include any other

documents such as those referenced in IN 87-20 (NUREG/CR-3551,

ORNL/N0AC-214 and EPRI/BWROG topical report, 1987 revision); (2) his

recommendations were made to stimulate interest in the review and

evaluation process; (3) his recommendation, to verify that Trojan's

design precluded excess hydrogen accumulation in the

Control / Auxiliary Building / Fuel Building complex from hydrogen

lines that may be routed through these areas, was based on personal

knowledge of the plant; (4) the control room was not considered

since there were no hydrogen lines in that area; (5) the Control

Building was listed because he did not know for sure that hydrogen s

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lines-were not routed through parts of this area; and (6) hydrogen

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storage on the roof of the control room was also not considered +

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since storage was not the topic addressed in IN 87-20.

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NPE management staff informed the inspectors that the OAR evaluation

target due date (July 3,1987) was changed due to their involvement

in refueling outage activities.

The individual that completed the initial evaluation informed the

inspectors that: (1) the scope of his evaluation was based on the

topic addressed in IN 87-20, guidance in the Standard Review Plan

(NUREG-0800), information in the FSAR, system drawing, a walk down

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thethe hydrogen

documents system's

referenced in IN line

87-20routing (, and review of PGE-1012; (2)

NUREG/CR-3551,ORNL/N0AC-214

) and EPRI/BWROG topical report, 1987 revision) were not reviewed; and

(3) the control room was not a concern since no hydrogen lines were

routed through this area.

The inspectors were also informed by this individual that the value

of 600 scfm, used in his evaluation to determine the flammability

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mixture in the VCT room, was based on information obtained from the

model number of one (middle valve) of three excess flow control

valves in the hydrogen supply manifold. The drawing he used only

listed one model number and he assumed that the other two valves had

the same flow rates, since their model numbers were not listed.

Based on the interview with cognizant NPE staff, the inspectors were

informed that the 600 scfm was the shut off flow for the excess flow

control bypass valve (GS-162) in the supply man 1 fold located on the

roof of the control room. This valve was normally isolated during

j routine operations and only used during filling of the turbine

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g , generator's hydrogen cooling system. The normal operation' of the

! hydrogen supply system was through excess control valves GS-037 and

GS-038 with a nominal flow rate of 25 scfm and shut off flow at' 75

scfm_. 'Both of these valves supplied the header to the VCT and the

generator's cooling system.

1 -* . Based on discussions with the individuals that completed the OAR

87-29 review', it appeared that they did not realize prior to the

Chemistry Team Inspection the 600 scfm flow rate was limited to the

f bypass flow path only.

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~ The TSM informed the inspectors that his request for a re-evaluation

of 0AR 87-29 was based on his engineering judgement that: (1) the 1

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initial evaluation was'not thorough based on his knowledge of the

l plant systems and areas and (2) to increase the ventilation in the

VCT room would be a very difficult and. costly task. The inspectors

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were also informed that he did not consider hydrogen storage because

the OAR did not address it.

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Based on interviews with cognizant NPE and NSRD staff, the licensee

could not confirm where the OAR resided during the period of

I November 25, 1987, to December 8, 1988. The individual that

completed the re-evaluation informed the inspectors that he may have

had the OAR in his possession; however, he was not positive.

The individual that completed the re-evaluation informed the

inspectors that: (1) the scope of his evaluation was based on the

topic addressed in IN 87-20, guidance in-the Standard Review Plan

(NUREG-0800), information in the FSAR, system drawing, and review of

PGE-1012; (2) the documents referenced in IN 87-20 (NUREG/CR-3551,

ORNL/N0AC-214 and EPRI/BWROG topical report, 1987 revision) were not

reviewed and (3) that any leakage of hydrogen into the VCT room was

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not considered to be a significant safety problem, since there was

no ignition source in the room and the VCT was designed to seismic

Class I requirements.

Based on an examination of. licensee diagrams, the inspectors noted

that the hydrogen supply control valves were exterior to the VCT

room and appeared to have been hard piped to the VCT within the

room. In addition, the level indicating units and control valves to

and from the VCT were also exterior to the room. The VCT was also

noted to be the only tank in the room and appeared to occupy a major

portion of the room's volume,

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Based on the above observations and interviews with NPE and NRSD

management, it appeared that the the documents referenced in IN 87-20

(NUREG/CR-3551, ORNL/NOAC-214 and EPRI/BWROG topical report, 1987

revision) were not reviewed by any of the persons responsible for the

reviews and evaluations associated with OAR 87-29. The initial review

and evaluation of the OAR appeared timely; however, the re-evaluation

appeared not to have been performed in a timely manner. One would

perceive that a matter originally considered to be conditionally

significant, a potential fire hazard, and could result in unsafe

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conditions not readily identifiable to plant operators would have

k received a more timely re-evaluation.

These matters were discussed with the licensee's staff during.the

inspection and at the exit interview on July 14, 1989. The inspectors

observations were acknowledged by the licensee. The inspectors were

informed that improvements.have been made in their Commitment Control

System to reduce delays in the 0AR review process.

The inspectors were also informed by the management staff and the Vice

' President, Nuclear, that since the referenced EPRI report was published

for BWR Plants, this document and other such documents for BWRs would not

receive the attention normally given to PWR documents. The licensee's

management staff stated that they believed their reviews and evaluations

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were consistent with the subject matter presented in IN 87-20 and that

'O the matter was'not considered to be a significant safety problem.

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Based on review of the concerns identified during the Chemistry Team

Inspection _on April 17-21, 1989, personnel interviews, observations ,

. during this' inspection (50-344/89-18), and in-office review of documents, 4

the inspectors made;the following additional observations:

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Prior to a recent change in the licensee's hydrogen storage

. facility, the hydrogen and nitrogen storage system was found as

- . described in the UFSAR. Trojan's Design Base Document'(DBD) No. 30,

Control Building-Ventilation Systems, dated September 16, 1987, did

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not. address the hydrogen storage facility's impact on the control

room. An independent design base review, completed by a contractor '

on September 29, 1988, stated in DBD C3, Section 4.1 (2):

" Gas storage tanks: All storage tanks were evaluated for

potential missile generation, and it was-determined that the H

and N 9 bulkgastanksontheroofoftheControlBuildingwoulb

produte the most significant and potentially damaging missiles

for safety-related equipment. These tanks have a relatively

high internal pressure (2,450 psig)..."

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...(see Appendix A, Open Item C3-0-06)."

Appendix A, Item C3-0-06, Description, read, in part:

"For the following items, Trojan UFSAR information was used in

defining design bases in this document; however, no supporting

documentation was found (subsection 4.1.2):

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( b) -pH and pN tanks mounted on the Control Building roof

cannot penetrate the 2 ft. 6 in, thick roof as stated on

UFSAR pages 3.5-16/17...." 1

Following the Chemistry Team Inspection (performed during the licensee's

refueling outage), the licensee, on the evening of April 21, 1989,

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isolated the hydrogen storage tanks and installed oxygen monitors (for

any potential nitrogen inleakage) in the control room.

The Manager, NPE, informed the inspectors that during a meeting with

Bechtel during the first week of May 1989, the Bechtel representatives

informed PGE that, based on a cursory engineering evaluation, the

existing hydrogen and nitrogen storage facility's did not have any

adverse effect on the control room habitability (detonation, missiles and

line breaks); however, a detailed analysis to confirm this would be

costly. The licensee's staff informed the inspectors that rather than

expending money on;an analysis, they elected to rel_ocate the hydrogen

storage facility as'it could be incorporated into other modifications

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already in progress and to assure that it will meet the EPRI guidelines.

'No detailed, analysis was performed to determine whether or not the

previous hydrogen storage facility on the roof of the control building

. represented a. safety problem to the control room or other nearby safety

related equipment.

By' letter, dated May 5, 1989, the licensee, informed the Commission that

_ PGE was going ~to relocate the bulk hydrogen storage tanks from the roof

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of the' Control Building prior to reactor restart. The letter also read,

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in part, that a complete evaluation, including the new storage facility

. location and any supporting analysis, would be submitted to the

commission by May 31, 1989.

During an Enforcement Conference held on May 12, 1989, at the NRC Region

V Office, related to security matters, the issue of hydrogen storage was

discussed. The licensee acknowledged the lack of timely action in

response to IN 87-20 but stated that'they believed the scope of their

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review was consistent with the topic addressed in the notice.

On May 31, 1989, PGE submitted their evaluation of the new hydrogen

storage system and the existing nitrogen system (on the roof of the

control room). No analysis ~ addressing the,old hydrogen system was

included in the report. The licensee also informed the Commission that

they would re-revaluate the hydrogen distribution system by July 14,

1989.

During the inspection the deportability of the hydrogen issue in

accordance with 10 CFR 50.73 requirements was discussed with the

licensee. At the exit meeting on July 14, 1989, the licensee informed

the inspectors that a report with their re-evaluation would be submitted

to the Commission by August 14, 1989, for information even though in

their view the matter was not reportable under the regulation.

The inspectors toured the area of the previous hydrogen storage facility

and the licensee's new storage facility. The inspectors verified that

the old storage tanks and fill station had been removed, as stated by the

licensee. The new hydrogen storage facility, includh g new tanks, was

located on the South side of the Cooling Tower. The hydrogen gas from

the new system to the plant was pressure reduced (2450 to 200 psig) and

supplied normal flow through two excess flow control valves with a shut

off flow of 75 scfm. The hydrogen supply lines were routed underground

from the Cooling Tower area to the South side of the Turbine Building,

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fl s#where they 'came out of the ground and ran over the Turbine Building roof

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to the roof of the Control Building. The hydrogen suppl

.this area was further pressure reduced (200 to 100,psig)y and to the VCT from

flowed

.through another flow control valve with a cut off flow of 5.5 scfm. .The

licensee installed the new system under the provisions of 10 CFR 50.59.

10 CFR 50, Appendix B, XVI., Corrective Action, reads in part:

'" Measures shall .be established to assure that conditions adverse to

quality, such as failures, malfunctions, deficiencies, deviations,

i defective material,. and equipment and nonconformances are promptly

identified and corrected...'."

The failure to take prompt corrective actions for a potential safety

problem was identified as an apparent violation of 10 CFR 50, Appendix

B.,XVI (50-344/89-18-01).

3. Exit Interview

-The inspectors met with the licensee representatives, denoted in

paragraph 1, at the conclusion of the inspection on July 14, 1989. The

scope and findings.of the inspection were summarized.

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The requirements of 10 CFR Part 50 Appendix B, XVI, were discussed. The

inspectors informed the licensee that the findings and observations made

during the inspection would be given further in-office review.

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